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Date:	Tue, 2 Mar 2010 01:12:46 -0800
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	Christopher Heiny <cheiny@...aptics.com>
Cc:	Linux Kernel <linux-kernel@...r.kernel.org>,
	Allie Xiong <axiong@...aptics.com>,
	William Manson <wmanson@...aptics.com>
Subject: Re: [RFC PATCH 1/1] input/touchscreen: Synaptics Touchscreen Driver

Hi Christofer,

On Wed, Feb 17, 2010 at 02:37:38PM -0800, Christopher Heiny wrote:
> Initial driver for Synaptics touchscreens using RMI4 protocol.
> 

I assume that since you sent it with git-send-email it was your
corporate mail server that murdered all identation and whitespace.
Please try sending next version using alternative server, like gmail or
maybe your personal account. On the off chance that the formatting used
in the driver was preserved intact - please remember that kernel uses
hard tabs for identation (8 chars, no expanding). Camel-casing is also
frowned upon.

> Signed-off-by: William Manson <WManson@...aptics.com>
> Signed-off-by: Allie Xiong <axiong@...aptics.com>
> Signed-off-by: Christopher Heiny <cheiny@...aptics.com>
> ---
> 
>  drivers/input/touchscreen/Kconfig            |   13 +
>  drivers/input/touchscreen/Makefile           |    1 +
>  drivers/input/touchscreen/rmi.h              |  214 +++++++++
>  drivers/input/touchscreen/rmi_app_touchpad.c |  490 +++++++++++++++++++++
>  drivers/input/touchscreen/rmi_core.c         |  602 ++++++++++++++++++++++++++
>  drivers/input/touchscreen/rmi_core.h         |   59 +++
>  drivers/input/touchscreen/rmi_function_11.c  |  333 ++++++++++++++
>  drivers/input/touchscreen/rmi_function_11.h  |   41 ++
>  drivers/input/touchscreen/rmi_functions.h    |  107 +++++
>  drivers/input/touchscreen/rmi_i2c.h          |   57 +++
>  drivers/input/touchscreen/rmi_i2c_gta01.c    |  125 ++++++
>  drivers/input/touchscreen/rmi_phys_i2c.c     |  555 ++++++++++++++++++++++++
>  12 files changed, 2597 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index dfafc76..319cb45 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -295,6 +295,19 @@ config TOUCHSCREEN_MIGOR
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called migor_ts.
>  
> +config TOUCHSCREEN_SYNAPTICS_RMI4_I2C
> +	tristate "Synaptics RMI4 I2C touchscreens"
> +	depends on I2C
> +	help
> +	  Say Y here if you have a Synaptics RMI4 I2C touchscreen connected to
> +   	  your system. This enables support for Synaptics RMI4 over I2C based

Spaces followed by tabs.

> +          touchscreens.

Wierd identation.
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a set of modules, choose M here: the
> +	  modules will be called rmi, rmi_app_touchpad, rmi_phys_i2c.
> +
>  config TOUCHSCREEN_TOUCHRIGHT
>  	tristate "Touchright serial touchscreen"
>  	select SERIO
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index d61a3b4..8e7b708 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_TOUCHSCREEN_USB_COMPOSITE)	+= usbtouchscreen.o
>  obj-$(CONFIG_TOUCHSCREEN_PCAP)		+= pcap_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
>  obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
> +obj-$(CONFIG_TOUCHSCREEN_SYNAPTICS_RMI4_I2C)	+= rmi_core.o rmi_app_touchpad.o rmi_function_11.o rmi_phys_i2c.o rmi_i2c_gta01.o

You have separated RMI core from touchpad. It would be prudent to build
these as separate modules as well (have touchpad "select" RMI).

>  obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)	+= touchit213.o
>  obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o
>  obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)	+= touchwin.o
> diff --git a/drivers/input/touchscreen/rmi.h b/drivers/input/touchscreen/rmi.h
> new file mode 100755
> index 0000000..aa45578
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi.h
> @@ -0,0 +1,214 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) Header File.
> + * Copyright (c) 2007-2009 Synaptics Incorporated
> + *
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#ifndef _RMI_H
> +#define _RMI_H
> +
> +/** RMI4 Protocol Support
> + */
> +
> +/** For each function present on the RMI device, we need to get the RMI4 Function
> + *  Descriptor info from the Page Descriptor Table. This will give us the
> + *  addresses for Query, Command, Control, Data and the Source Count (number
> + *  of sources for this function) and the function id.
> + */
> +struct rmi_function_descriptor {
> +  unsigned char queryBaseAddr;
> +  unsigned char commandBaseAddr;
> +  unsigned char controlBaseAddr;
> +  unsigned char dataBaseAddr;
> +  unsigned char interruptSrcCnt;
> +  unsigned char functionNum;
> +};
> +
> +/** For each function present on the RMI device, there will be a corresponding
> + * entry in the functions list of the rmi_module_info structure.  This entry
> + * gives information about the number of data sources and the number of data
> + * registers associated with the function.
> + * \see rmi_module_info
> + */

If you want to use markups for functions/data structures please forllow
kerneldoc format:

	Documentation/kernel-doc-nano-HOWTO.txt

Nothing in kernel understands \xxx (\node, \see, etc) tags.

> +struct rmi_function_info {
> +  unsigned char functionNum;
> +
> +  /** This is the number of data sources associated with the function.
> +   * \note This is not the total number of data registers associated with
> +   * this function!
> +   * \see data_regs
> +   */
> +  unsigned char numSources;
> +
> +  /** This is the number of data points supported - for example, for
> +   *  function $11 (2D sensor) the number of data points is equal to the number
> +   *  of fingers - for function $19 (buttons)it is the number of buttons.
> +   */
> +  unsigned char numDataPoints;
> +  /** This is the number of data registers to read.
> +   */
> +  unsigned char dataRegBlockSize;
> +
> +  /** This is the interrupt register and mask - needed for enabling the interrupts
> +   *  and for checking what source had caused the attention line interrupt.
> +   */
> +  unsigned char interruptRegister;
> +  unsigned char interruptMask;
> +
> +  /** This is the RMI function descriptor associated with this function.
> +   *  It contains the Base addresses for the functions query, command,
> +   *  control, and data registers.
> +   */
> +  struct rmi_function_descriptor funcDescriptor;
> +
> +  /** Standard kernel linked list implementation.
> +   * Documentation on how to use it can be found at
> +   * http://isis.poly.edu/kulesh/stuff/src/klist/.
> +   */

Yep, we know ;)

> +  struct list_head link;
> +};
> +
> +/** This encapsulates the information found using the RMI4 Function $01
> + *  query registers. There is only one Function $01 per device.
> + *
> + *  Assuming appropriate endian-ness, you can populate most of this
> + *  structure by reading query registers starting at the query base address
> + *  that was obtained from RMI4 function 0x01 function descriptor info read
> + *  from the Page Descriptor Table.
> + *
> + *  Specific register information is provided in the comments for each field.
> + *  For further reference, please see the <i>Synaptics RMI4 Interfacing
> + *  Guide</i> document.

Is it publicly available?

> + */
> +struct rmi_module_info {
> +  /** The Protocol Major Version number.
> +   */
> +  unsigned rmi_maj_ver;
> +
> +  /** The Protocol Minor Version number.
> +   */
> +  unsigned rmi_min_ver;
> +
> +  /** The manufacturer identification byte.
> +   */
> +  unsigned char mfgid;
> +
> +  /** The Product Properties information.
> +   */
> +  unsigned char properties;
> +
> +  /** The product info bytes.
> +   * You can build a product info string using the following printf
> +   * format and args:
> +   * \code printf("%i %02i", productInfo[0], productInfo[1]); \endcode
> +   */
> +  unsigned char prod_info[2];
> +
> +   /** Date Code - Year, Month, Day.
> +    */
> +  unsigned char date_code[3];
> +
> +  /** Tester ID (14 bits).
> +   */
> +  unsigned short tester_id;
> +
> +  /** Serial Number (14 bits).
> +   */
> +  unsigned short serial_num;
> +
> +  /** A null-terminated string that identifies this particular product.
> +   */
> +  char prod_id[10];
> +
> +  /** A list of the function presence queries.
> +   * This list uses the standard kernel linked list implementation.
> +   * Documentation on on how to use it can be found at
> +   * http://isis.poly.edu/kulesh/stuff/src/klist/.
> +   * \see rmi_function_info
> +   */
> +  struct list_head functions;
> +};
> +
> +struct rmi_phys_driver {
> +  char *name;
> +  int  (*write)(struct rmi_phys_driver *pd, unsigned short address, char data);
> +  int  (*read)(struct rmi_phys_driver *pd, unsigned short address, char *buffer);
> +  int  (*write_multiple)(struct rmi_phys_driver *pd, unsigned short address, char *buffer, int length);
> +  int  (*read_multiple)(struct rmi_phys_driver *pd, unsigned short address, char *buffer, int length);
> +  void (*attention)(struct rmi_phys_driver *pd, int instance);
> +  int  (*get_attention)(struct rmi_phys_driver *pd);
> +  int  polling_required;
> +  /* Private elements of the structure */
> +  /** Standard kernel linked list implementation.
> +   * Documentation on how to use it can be found at
> +   * http://isis.poly.edu/kulesh/stuff/src/klist/.
> +   */
> +  struct list_head drivers;
> +  struct rmi_application *app;
> +  struct rmi_module_info rmi;
> +  struct module *module;
> +};
> +
> +int rmi_read(struct rmi_application *app, unsigned short address, char *dest);
> +int rmi_write(struct rmi_application *app, unsigned short address, unsigned char data);
> +int rmi_read_multiple(struct rmi_application *app, unsigned short address, char *dest, int length);
> +int rmi_write_multiple(struct rmi_application *app, unsigned short address, unsigned char *data, int length);
> +int rmi_register_phys_driver(struct rmi_phys_driver *rpd);
> +int rmi_unregister_phys_driver(struct rmi_phys_driver *rpd);
> +
> +struct rmi_application *rmi_register_application(const char *name,
> +  void (*attention)(struct rmi_phys_driver *pd, int instance),
> +  int (*probe)(struct rmi_application *app, const struct rmi_module_info *rmi),
> +  void (*config)(struct rmi_application *app));
> +
> +void rmi_unregister_application(struct rmi_application *app);
> +int  rmi_polling_required(struct rmi_application *app);
> +int  rmi_get_attn(struct rmi_application *app);
> +
> +/** Set this to 1 to turn on code used in detecting buffer leaks. */
> +#define RMI_ALLOC_STATS 1
> +
> +#if RMI_ALLOC_STATS
> +extern int appallocsrmi;
> +extern int rfiallocsrmi;
> +extern int fnallocsrmi;
> +
> +#   define INC_ALLOC_STAT(X)   (X##allocsrmi++)
> +#   define DEC_ALLOC_STAT(X)   \
> +	do { \
> +	  if (X##allocsrmi) X##allocsrmi--; \
> +	  else printk(KERN_DEBUG "Too many " #X " frees\n"); \
> +	} while (0)
> +#   define CHECK_ALLOC_STAT(X) \
> +	do { \
> +	  if (X##allocsrmi) printk(KERN_DEBUG "Left over " #X " buffers: %d\n", \
> +		X##allocsrmi); \
> +	} while (0)
> +#else
> +#   define INC_ALLOC_STAT(X)   do { } while (0)
> +#   define DEC_ALLOC_STAT(X)   do { } while (0)
> +#   define CHECK_ALLOC_STAT(X) do { } while (0)
> +#endif
> +
> +#endif
> +
> +/* vim600: set noexpandtab sw=8 ts=8 :*/
> diff --git a/drivers/input/touchscreen/rmi_app_touchpad.c b/drivers/input/touchscreen/rmi_app_touchpad.c
> new file mode 100755
> index 0000000..b3d0b99
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_app_touchpad.c
> @@ -0,0 +1,490 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) TouchPad Application Layer Driver.
> + * Copyright (c) 2007-2009 Synaptics Incorporated
> + *
> + *
> + * This code implements a polling mechanism with backoff as well as
> + * interrupt-driven sampling.  For polling, the module has two parameters:
> + * polljif (Poll Jiffies) and hspolljif (High Speed Poll Jiffies).  The driver
> + * polls at polljif until it sees a press, and then it polls at hspolljif.
> + * When there is no longer a touch, it reverts to the polljif period.
> + *
> + * The polljif parameter can be changed during run time like this:\code
> + *   echo 100 > /sys/module/rmi_app_touchpad/parameters/polljif
> + * \endcode
> + *
> + * That will change the pollrate to 1 per second (assuming HZ == 100).  The
> + * same is true for hspolljif.
> + *
> + * The parameters have no effect for the interrupt-driven case.
> + *
> + * Note that it is the lower-level drivers that determine whether this driver
> + * has to do polling or interrupt-driven.  Polling can always be done, but if
> + * we have an interrupt connected to the attention (ATTN) line, then it is
> + * better to be interrupt driven.
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/delay.h>
> +#include <linux/kthread.h>
> +#include <linux/freezer.h>
> +#include <linux/input.h>
> +
> +#include "rmi.h"
> +#include "rmi_core.h"
> +#include "rmi_functions.h"
> +
> +#if RMI_ALLOC_STATS
> +  static int pollallocsrmi;
> +#endif
> +
> +#define RMI_REPORT_RATE_40 (1 << 6)
> +
> +/** The number of jiffies between polls without touches */
> +static int polljif = HZ/20;
> +/** The number of jiffies between polls with touches */
> +static int hspolljif = HZ/40;
> +module_param(polljif, int, 0644);
> +module_param(hspolljif, int, 0644);
> +MODULE_PARM_DESC(polljif,   "How many jiffies between low speed polls.");
> +MODULE_PARM_DESC(hspolljif, "How many jiffies between high speed polls.");

Jiffies is not the best units of measurement. You need to use fractions
of seconds - something that does not depent on processor speed and
current value of HZ.

> +
> +static struct rmi_application *app;
> +static struct completion touch_completion;
> +static struct completion thread_comp;
> +struct task_struct *kthread;
> +static int time_to_quit;

bool.

> +static struct input_dev *input;

One device per system? This is a harsh limitation and something that
I'd rather not have.

> +
> +extern unsigned short fn01ControlBaseAddr;	/* RMI4 device control == function 0x01 */
> +extern unsigned int interruptRegisterCount;   /* number of total interrupt registers to read */
> +
> +extern struct list_head fns_list;
> +
> +/**
> + * This is the function we pass to the RMI4 subsystem so we can be notified
> + * when attention is required.  It may be called in interrupt context.
> + */
> +static void attention(struct rmi_phys_driver *rpd, int instance)
> +{
> +  /* All we have to do is wake up the kernel sampling thread. */
> +  complete(&touch_completion);

I do not see you re-initializing this completion anywhere so once
signalled your thread will be spinning with wait_for_completion() being
a noop.

> +}
> +
> +/**
> + * This is the meat of the driver.  It reads in all data sources and reports them to
> + * the input subsystem.  It is used for both polling and interrupt driven operation.
> + */
> +int report_sensor_data(struct rmi_application *app)
> +{
> +  unsigned char interruptStatus[4] = {0, 0, 0, 0};
> +  int touch; /* number of touch points - fingers or buttons */
> +  struct rmi_functions *fn;
> +  struct rmi_function_info *rfi;
> +  struct rmi_phys_driver *rpd;
> +  struct rmi_module_info *rmi;
> +  static int num_error_reports;
> +
> +  touch = 0;
> +
> +  /* Get the interrupt status from the function $01 control register+1 to find
> +	 which source(s) were interrupting so we can read the data from the
> +	 source(s) (2D sensor, buttons, etc.). */
> +  if (rmi_read_multiple(app, fn01ControlBaseAddr + 1, interruptStatus, interruptRegisterCount)) {
> +	printk(KERN_ERR "Could not read interrupt status registers 0x%x\n", fn01ControlBaseAddr + 1);
> +	return 0;
> +  }
> +
> +  /* check each function that has data sources and if the interrupt for that triggered
> +	 then call that RMI4 functions report() function to gather data and report it to the input
> +	 subsystem
> +  */
> +  rpd  = app->rpd; /* get ptr to rmi_physical_driver from app */
> +  rmi  = &(rpd->rmi); /* get ptr to rmi_module_info from physical driver */
> +
> +  list_for_each_entry(rfi, &rmi->functions, link) {
> +	if (rfi->numSources) {
> +	  if (interruptStatus[rfi->interruptRegister] & rfi->interruptMask) {
> +		bool found;
> +		found = false;
> +		list_for_each_entry(fn, &fns_list, link) {
> +		  if (rfi->functionNum == fn->functionNum) {
> +			found = true;
> +			if (fn->report) {
> +			  touch = fn->report(app, rfi, fn->input);
> +			} else {
> +			  num_error_reports++;
> +			  if (num_error_reports < 6) {
> +				/* the developer did not add in the pointer to the report
> +				   function into rmi4_supported_data_src_functions */
> +				printk(KERN_ERR "rmi_app_touchpad.report_sensor_data: no find report function for function 0x%x\n", fn->functionNum);
> +			  }
> +			  break;
> +			}
> +		  }
> +		}
> +
> +		if (!found) {
> +		  num_error_reports++;
> +		  if (num_error_reports < 6) {
> +			/* if no support found for this RMI4 function it means the
> +			   developer did not add the appropriate function pointer
> +			   list into the rmi4_supported_data_src_functions array
> +			   and/or did not bump up the number of supported RMI4
> +			   functions in rmi.h as required */
> +			printk(KERN_ERR "rmi_app_touchpad.report_sensor_data: could not any support for function 0x%x\n", fn->functionNum);
> +		  }
> +		}
> +	  }
> +	}
> +  }
> +
> +  /* return the number of touch points - fingers down and/or buttons pressed, etc. */
> +  return touch;
> +}
> +
> +
> +/**
> + * This is a kernel thread that processes packets when we receive them.  It is
> + * only used for the interrupt-driven case.  Polling may also be done in this
> + * driver and doesn't use this thread (although I suppose it could be modified
> + * to do polling, too, instead of using timers).
> + */
> +int rmitouchd(void *param)
> +{
> +  struct rmi_application *app = (struct rmi_application *)param;
> +
> +  daemonize("rmitouchd");

No need to daemonize if you use ktherad_run().

> +
> +  while (!kthread_should_stop()) {
> +	if (time_to_quit)
> +	  break;

Why do you need separate flag? kthread_should_stop() should be enough.

> +
> +	/* wait for interrupt from ATTN line */
> +	wait_for_completion_interruptible(&touch_completion);

wait_event_freezable().

> +	if (time_to_quit)
> +	  break;
> +
> +	try_to_freeze();
> +	do {
> +	  report_sensor_data(app);
> +	  /* check if time to quit so we don't loop when we are in mod_exit(). */
> +	  if (time_to_quit)
> +		break;
> +	} while (rmi_get_attn(app));

You still want to be able to suspend even if someone is keeping finger
on a touchpad... You need to check freeze state alongside of checking
attention.

> +  }
> +
> +  complete_and_exit(&thread_comp, 0);

No need for this either.

> +}
> +
> +/* Head of the list to keep track of who is polling.  This is so we can
> + * properly shut down the timers on exit. */
> +static struct list_head pollers;
> +
> +/* Simple structure to keep track of things */
> +struct poll_instance {
> +  struct delayed_work dw;
> +  struct rmi_application *app;
> +  struct list_head link;
> +};
> +
> +/* The main routine for the polling case. */
> +static void poll_work_callback(struct work_struct *data)
> +{
> +  struct delayed_work *dw = container_of(data, struct delayed_work, work);
> +  struct poll_instance *pi = container_of(dw, struct poll_instance, dw);
> +  static int calls_with_no_data;
> +  int touch = 0;
> +
> +  if (time_to_quit)
> +    return;
> +
> +  touch = report_sensor_data(pi->app);
> +
> +  /* This code implements a backoff.  If we have a call with data being
> +   * received, we decrease the time between polls to hspolljif.  If
> +   * there are several calls at that faster rate that do not have data,
> +   * we go back to slower polling.
> +   */
> +  if (touch)
> +	calls_with_no_data = 0;
> +  if (!time_to_quit) {	/* Don't schedule if it's time to quit. */
> +	if (calls_with_no_data > 5) {
> +	  schedule_delayed_work(dw, polljif);

This is wrong. You need

	schedule_delayed_work(dw, jiffies + polljif);

or

	schedule_delayed_work(dw, jiffies + msecs_to_jiffies(poll_time));

> +	} else {
> +	  if (!touch)
> +		calls_with_no_data++;
> +	  schedule_delayed_work(dw, hspolljif);

Same here but hspoll_time.

> +	}
> +  }
> +}
> +
> +/**
> + * This is the probe function passed to the RMI4 subsystem that gives us a
> + * chance to recognize an RMI4 device.  In this case, we're looking for
> + * Synaptics devices that have data sources - such as touch screens, buttons, etc.
> + */
> +static int probe(struct rmi_application *app, const struct rmi_module_info *rmi)
> +{
> +  struct rmi_function_info *rfi;
> +  int data_sources = 0;
> +  int retval = 0;
> +
> +  if (!rmi) {
> +	printk(KERN_ERR "rmi_app_touchpad.probe: "
> +	  "Invalid module info: %p\n", rmi);
> +	return 0;
> +  }
> +
> +  /* Make sure this is a Synaptics device */
> +  if (rmi->mfgid != 1) { /* Synaptics */
> +	printk(KERN_ERR "rmi_app_touchpad.probe: "
> +	  "Invalid mfg id: %d\n", rmi->mfgid);
> +	return 0;
> +  }
> +
> +  /* for each function entry in the list accumulate it's number of data sources */
> +  list_for_each_entry(rfi, &rmi->functions, link) {
> +	  data_sources += rfi->numSources;
> +  }
> +
> +  if (data_sources) {
> +	retval = 1;
> +	/* We have detected one or more data sources such as a 2D Sensors, buttons, etc. */
> +	printk(KERN_ERR "rmi_app_touchpad.probe: "
> +	  "Found %d data sources for : %p\n", data_sources, rmi);
> +  } else {
> +	/* we don't have any data sources for this sensor - oops! - either an un-flashed sensor or bad!! */
> +	printk(KERN_ERR "rmi_app_touchpad.probe: "
> +	  "No data sources found for : %p\n", rmi);
> +  }
> +
> +  return retval;
> +}
> +
> +static void config(struct rmi_application *app)
> +{
> +  /* For each data source we had detected print info and set up interrupts or polling. */
> +  struct rmi_function_info *rfi;
> +  struct rmi_phys_driver *rpd;
> +  struct rmi_module_info *rmi;
> +
> +  rpd = app->rpd; /* get ptr to rmi_physical_driver from app */
> +  rmi = &(rpd->rmi); /* get ptr to rmi_module_info from physical driver */
> +
> +  list_for_each_entry(rfi, &rmi->functions, link) {
> +	if (rfi->numSources) /* if this function has data sources associated with it...*/ {
> +	  /* Get and print some info about the data sources... */
> +	  struct rmi_functions *fn;
> +	  bool found;
> +
> +	  found = false;
> +	  list_for_each_entry(fn, &fns_list, link) {
> +		/* check if function number matches - if so call that config function */
> +		if (fn->functionNum == rfi->functionNum) {
> +		  found = true;
> +		  if (fn->config) {
> +			fn->config(app, rfi);
> +		  } else {
> +			/* the developer did not add in the pointer to the config
> +			   function into rmi4_supported_data_src_functions */
> +			printk(KERN_ERR "rmi_app_touchpad.config - no config function for function 0x%x\n", rfi->functionNum);
> +			break;
> +		  }
> +		}
> +	  }
> +	  if (!found) {
> +		/* if no support found for this RMI4 function it means the
> +		   developer did not add the appropriate function pointer list
> +		   into the rmi4_supported_data_src_functions array and/or did
> +		   not bump up the number of supported RMI4 functions in rmi.h as
> +		   required */
> +		printk(KERN_ERR "rmi_app_touchpad.config - could not find support for function 0x%x\n", rfi->functionNum);
> +	  }
> +
> +	  /* if we are not doing polling then enable the interrupts for the
> +		 data sources for this function */
> +	  if (!rmi_polling_required(app)) {
> +		/* Turn on interrupts for this functions data sources. */
> +		rmi_write(app, fn01ControlBaseAddr + 1 + rfi->interruptRegister, rfi->interruptMask);
> +		printk(KERN_INFO "rmi_app_touchpad.config -  Interrupt Driven - turning on interrupts for function 0x%x\n", rfi->functionNum);
> +	  }
> +	}
> +  }
> +
> +  /* if we are not polling we need to set up the interrupt thread - otherwise we need to
> +	 set up the polling callback and worker thread. */
> +  if (!rmi_polling_required(app)) {
> +	/* We're interrupt driven, so turn on the thread. */
> +	kthread = kthread_run(&rmitouchd, app, "rmitouchd");
> +
> +	if (HZ < 500) {
> +	  /* The default polling frequency of 80 times per
> +	   * second is too fast (the Linux time slice for
> +	   * sub-GHz processors is only 100 times per second).
> +	   * So program it to 40.
> +	   */
> +	  rmi_write(app, fn01ControlBaseAddr, RMI_REPORT_RATE_40);
> +	}
> +  } else {
> +	/* We're polling driven, so set up the polling callback and worker thread */
> +	struct poll_instance *pi;
> +	pi = kmalloc(sizeof(*pi), GFP_KERNEL);
> +
> +	if (!pi) {
> +	  printk(KERN_ERR "rmi_app_touchpad.config: "
> +		"Out of memory claiming %s\n",
> +		rmi->prod_id);
> +	  return;
> +	}
> +	INC_ALLOC_STAT(poll);

Bah, this is too complex for no good reason. Just make dw embedded in
rmi_application instance.

> +	INIT_DELAYED_WORK(&pi->dw, poll_work_callback);
> +
> +	pi->app	 = app;
> +	list_add_tail(&pi->link, &pollers);
> +	schedule_delayed_work(&pi->dw, polljif);

Why can't we also use workqueue when in interrupt mode or use thread
when in polling mode. I think these 2 modes should be combined together
as much as possible.

> +  }
> +}
> +
> +/**
> + * The module initialization function in which we register as a RMI4
> + * application driver.  We also register with the input subsystem so we can
> + * pass coordinates to it.
> + */
> +static int __init mod_init(void)

Call it rmi_app_touchpad_init(). It makes so much easier to see crash
trace.

> +{
> +  struct rmi_functions *fn;
> +  int retval;
> +
> +  retval = 0;
> +
> +  printk(KERN_INFO "rmi_app_touchpad.mod_init: RMI4 TouchPad Driver\n");
> +
> +  INIT_LIST_HEAD(&pollers);
> +
> +  time_to_quit = 0;
> +  init_completion(&touch_completion);
> +  init_completion(&thread_comp);
> +
> +  /* NOTE: we are creating only one input dev file for this but theoretically
> +	 you could create a separate one for each data source and store it below.
> +	 This will let you put 2D sensor events into one dev file, button events into
> +	 a separate dev file, other data source event like GPIOs, etc. into yet a
> +	 third dev file. As this is being coded it will dump all events into the
> +	 one dev file.
> +   */
> +  input = input_allocate_device();
> +  if (input == NULL) {
> +	printk(KERN_ERR "rmi_app_touchpad.mod_init:  Failed to allocate memory for a new input device.\n");
> +	return -ENOMEM;
> +  }
> +
> +  input->name = "RMI4 Touchpad";
> +  input->phys = "rmi_app_touchpad";
> +
> +  /* Set input device specific params for each data source...*/
> +  list_for_each_entry(fn, &fns_list, link) {
> +	if (fn->init) {
> +	  fn->input = input; /* store the input_dev ptr for use later */
> +	  fn->init(fn->input);

Can fn->init fail for any reason?

> +	} else {
> +	  /* the developer did not add in the pointer to the init function into rmi4_supported_data_src_functions */
> +	  printk(KERN_ERR "rmi_app_touchpad.mod_init: no init function for function 0x%x\n", fn->functionNum);

If this is an error why don't you handle it when building fns_list?

> +	}
> +  }
> +
> +  retval = input_register_device(input);
> +
> +  if (retval) {
> +	printk(KERN_ERR "rmi_app_touchpad.mod_init:  Failed input_register_device.\n");

What about undoing the parts of the setup that were successful?

> +	return retval;
> +  }
> +
> +  app = rmi_register_application("rmi4_touchpad", attention, probe, config);
> +
> +  if (!app) {
> +	printk(KERN_ERR "rmi_app_touchpad.mod_init:  Failed to register app.\n");
> +	input_unregister_device(input);
> +	retval = -ENODEV;
> +  }
> +
> +  return retval;
> +}
> +
> +/**
> + * The module exit function.
> + */
> +static void __exit mod_exit(void)
> +{
> +  struct poll_instance *pi, *pi_tmp;
> +
> +  printk(KERN_INFO "rmi_app_touchpad.mod_exit: RMI4 TouchPad Driver\n");
> +
> +  time_to_quit = 1;
> +
> +  complete(&touch_completion); /* Kick the thread awake */

kthread_stop() is what you should be calling and it will wait for thread
to exit. You won't be needing raising touch_completion here nor wait for
thread_comp below.

> +  list_for_each_entry(pi, &pollers, link) {
> +	cancel_delayed_work(&pi->dw);	/* Cancel any pending polls */

cancel_delayed_work_sync(), otherwise work may rearm itself.

> +  }
> +  flush_scheduled_work();	/* Make sure all pollers are stopped */

and then it is not needed.

> +  if (kthread)
> +	wait_for_completion(&thread_comp);
> +
> +  /* Unregister everything */
> +  printk(KERN_WARNING "rmi_app_touchpad.mod_exit: Unregistering app - %s\n", app->name);
> +  rmi_unregister_application(app);
> +  input_unregister_device(input);
> +
> +  /* Free up the structures */
> +  list_for_each_entry_safe(pi, pi_tmp, &pollers, link) {
> +	list_del(&pi->link);
> +	kfree(pi);
> +	DEC_ALLOC_STAT(poll);
> +  }
> +
> +  CHECK_ALLOC_STAT(poll);

Not needed if you embed wq in application.

> +}
> +
> +/** Standard driver module information - the author of the module.
> + */

Please get rid of comments taht do not add any useful information.

> +MODULE_AUTHOR("Synaptics, Inc.");
> +/** Standard driver module information - a summary description of this module.
> + */
> +MODULE_DESCRIPTION("RMI4 Driver");
> +/** Standard driver module information - the license under which this module
> + * is included in the kernel.
> + */
> +MODULE_LICENSE("GPL");
> +
> +/** Specifies to the kernel that the mod_init() function should be called when
> + * the module is loaded.
> + * \see mod_init()
> + */
> +module_init(mod_init);


> +/** Specifies to the kernel that the mod_exit() function should be called when
> + * the module is unloaded.
> + * \see mod_exit()
> + */
> +module_exit(mod_exit);
> +
> +/* vim600: set noexpandtab sw=8 ts=8 :*/
> diff --git a/drivers/input/touchscreen/rmi_core.c b/drivers/input/touchscreen/rmi_core.c
> new file mode 100755
> index 0000000..fdedd09
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_core.c
> @@ -0,0 +1,602 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) Data Layer Driver.
> + * Copyright (C) 2007 - 2009, Synaptics Incorporated
> + *
> + *
> + * This protocol is layered as follows.
> + *
> + * <pre>
> + *  +----------------------------------------+
> + *  |										|
> + *  |			  Application			   |
> + *  |										|
> + *  +----------------------------------------+
> + *  |										|
> + *  |			   RMI4 Driver			  | Data Layer (THIS DRIVER)
> + *  |			  (this file)			   |
> + *  +-----+-----+-------+----------+---------+
> + *  | I2C | SPI | SMBus |		etc.		| Physical Layer
> + *  +-----+-----+-------+----------+---------+
> + *</pre>
> + *  Each of the physical layer drivers is contained in a file called
> + *  rmi_phys_xxx.c.  Someone compiling the kernel enables CONFIG_RMI and then
> + *  one or more CONFIG_RMI_xxx options in the .config file.  For example, when
> + *  CONFIG_RMI_I2C=m is enabled, a rmi.ko and a rmi_phys_i2c.ko will be
> + *  compiled.  rmi_phys_i2c.ko will depend on rmi.ko, so when rmi_phys_i2c.ko
> + *  is loaded, rmi.ko will automatically be loaded.  Each of the physical
> + *  layer drivers is a platform_driver that may handle suspend/resume, etc.,
> + *  so this driver does not do so.
> + *
> + *  The register paradigm of RMI is a "pull" rather than "push" data flow.
> + *  As such, it is the application driver that needs to implement either
> + *  polling or interrupt driven, and the physical driver merely handles
> + *  the register accesses.  For interrupt driven, the application registers
> + *  an "attention" function that may be called in interrupt context by the
> + *  physical driver if an attention interrupt is available.  The physical
> + *  driver notifies the application through the polling_required variable,
> + *  and the application driver must do one or the other based on this variable.
> + *
> + *  At this point in time, there can only be one application driver per
> + *  physical driver.
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +static const char drvname[] = "rmi4";
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/miscdevice.h>
> +#include <linux/fs.h>
> +#include <linux/delay.h>
> +#include <asm/uaccess.h>
> +
> +#include "rmi.h"
> +#include "rmi_core.h"
> +#include "rmi_functions.h"
> +
> +/* we need these to control and query interrupts */
> +unsigned short fn01QueryBaseAddr;	 /* RMI4 device control */
> +EXPORT_SYMBOL(fn01QueryBaseAddr);
> +unsigned short fn01ControlBaseAddr;
> +EXPORT_SYMBOL(fn01ControlBaseAddr);
> +unsigned int interruptRegisterCount;
> +EXPORT_SYMBOL(interruptRegisterCount);
> +
> +#define PDT_START_SCAN_LOCATION 0x00E9
> +#define PDT_END_SCAN_LOCATION 0x000A
> +#define PDT_ENTRY_SIZE 0x0006
> +
> +static LIST_HEAD(phys_drivers);
> +static DEFINE_MUTEX(phys_drivers_mutex);
> +static LIST_HEAD(app_drivers);
> +static DEFINE_MUTEX(app_drivers_mutex);
> +static LIST_HEAD(fns_list);
> +EXPORT_SYMBOL(fns_list);

Exporting lists like this is not pretty. It would be much better if RMI
core provided proper iterators and accessor functions.

> +static DEFINE_MUTEX(fns_mutex);
> +EXPORT_SYMBOL(fns_mutex);
> +static DEFINE_MUTEX(rfi_mutex);
> +EXPORT_SYMBOL(rfi_mutex);
> +
> +#if RMI_ALLOC_STATS
> +  int appallocsrmi = 0;
> +  EXPORT_SYMBOL(appallocsrmi);
> +  int rfiallocsrmi = 0;
> +  EXPORT_SYMBOL(rfiallocsrmi);
> +  int fnallocsrmi = 0;
> +  EXPORT_SYMBOL(fnallocsrmi);
> +#endif
> +
> +int rmi_read(struct rmi_application *app, unsigned short address, char *dest)
> +{
> +  struct rmi_phys_driver *rpd = app->rpd;
> +  if (!app->rpd)
> +	return -ENODEV;
> +  return rpd->read(rpd, address, dest);
> +}
> +EXPORT_SYMBOL(rmi_read);
> +
> +int rmi_write(struct rmi_application *app, unsigned short address, unsigned char data)
> +{
> +  struct rmi_phys_driver *rpd = app->rpd;
> +  if (!app->rpd)
> +	return -ENODEV;
> +  return rpd->write(rpd, address, data);
> +}
> +EXPORT_SYMBOL(rmi_write);
> +
> +int rmi_read_multiple(struct rmi_application *app, unsigned short address, char *dest, int length)
> +{
> +  struct rmi_phys_driver *rpd = app->rpd;
> +  if (!app->rpd)
> +	return -ENODEV;
> +  return rpd->read_multiple(rpd, address, dest, length);
> +}
> +EXPORT_SYMBOL(rmi_read_multiple);
> +
> +int rmi_write_multiple(struct rmi_application *app, unsigned short address, unsigned char *data, int length)
> +{
> +  struct rmi_phys_driver *rpd = app->rpd;
> +  if (!app->rpd)
> +	return -ENODEV;
> +  return rpd->write_multiple(rpd, address, data, length);
> +}
> +EXPORT_SYMBOL(rmi_write_multiple);
> +
> +int rmi_polling_required(struct rmi_application *app)
> +{
> +  return app->polling_required;
> +}
> +EXPORT_SYMBOL(rmi_polling_required);
> +
> +int rmi_get_attn(struct rmi_application *app)
> +{
> +  if (!app->rpd)
> +	return -ENODEV;
> +  return app->rpd->get_attention(app->rpd);
> +}
> +EXPORT_SYMBOL(rmi_get_attn);
> +
> +/*
> +   This function searches for a match between an app driver and physical
> +   driver and binds them together.
> +*/
> +static void match_and_bind(struct rmi_application *app, struct rmi_phys_driver *rpd)
> +{
> +  app->polling_required = rpd->polling_required;
> +  if (app->probe(app, &rpd->rmi)) {
> +	/* Found a match, bind them together. */
> +	/** The try_module_get() makes sure that the physical
> +	 * driver cannot be unloaded while a app driver is
> +	 * using it.
> +	 */
> +	if (try_module_get(rpd->module)) {
> +	  app->rpd = rpd;
> +	  rpd->app = app;
> +	  printk(KERN_INFO "%s: %s bound to %s\n", drvname, app->name, rpd->name);
> +	  rpd->attention = app->attention;
> +	  app->config(app);
> +	}
> +  } else {
> +	app->polling_required = 0;
> +  }
> +}
> +
> +int rmi_register_phys_driver(struct rmi_phys_driver *rpd)
> +{
> +  struct rmi_application *app;
> +  int i;
> +  unsigned char std_queries[21];
> +  unsigned char interruptCount;
> +  struct rmi_function_info *rfi;
> +  struct rmi_function_descriptor rmi_fd;
> +  struct rmi_functions *fn;
> +  bool found;
> +  int retval;
> +
> +  if (!rpd->name) {
> +	printk(KERN_ERR "%s: Physical driver must specify a name\n", drvname);
> +	return -EINVAL;
> +  }
> +  if (!rpd->write) {
> +	printk(KERN_ERR "%s: Physical driver %s must specify a writer.\n",  drvname, rpd->name);
> +	return -EINVAL;
> +  }
> +  if (!rpd->read) {
> +	printk(KERN_ERR "%s: Physical driver %s must specify a reader.\n", drvname, rpd->name);
> +	return -EINVAL;
> +  }
> +  if (!rpd->write_multiple) {
> +	printk(KERN_ERR "%s: Physical driver %s must specify a multiple writer.\n",  drvname, rpd->name);
> +	return -EINVAL;
> +  }
> +  if (!rpd->read_multiple) {
> +	printk(KERN_ERR "%s: Physical driver %s must specify a multiple reader.\n", drvname, rpd->name);
> +	return -EINVAL;
> +  }
> +  if (!rpd->module) {
> +	printk(KERN_ERR "%s: Physical driver %s must specify a module.\n",  drvname, rpd->name);
> +	return -EINVAL;
> +  }
> +
> +  pr_debug("%s: Registering phys driver %s\n", drvname, rpd->name);
> +
> +  rpd->attention = 0;
> +
> +  /* Get some information from the device */
> +  {
> +	printk(KERN_INFO "%s: Functions:\n", drvname);
> +
> +	interruptCount = 0;
> +
> +	/* init the physical drivers RMI module info list of functions */
> +	INIT_LIST_HEAD(&rpd->rmi.functions);
> +
> +	/* Read the Page Descriptor Table to determine what functions are present */
> +	for (i = PDT_START_SCAN_LOCATION; i > PDT_END_SCAN_LOCATION; i -= PDT_ENTRY_SIZE) {
> +	  retval = rpd->read_multiple(rpd, i, (char *)&rmi_fd, sizeof(rmi_fd));
> +	  if (!retval) {
> +		rfi = NULL;
> +		if (rmi_fd.functionNum) {
> +		  switch (rmi_fd.functionNum & 0xff) {
> +		  case 0x01:
> +			printk(KERN_INFO "%s:   Fn $01 Found - RMI Device Control\n", drvname);
> +			/* Save Fn $01 query and control base addresses since
> +			   we'll need them later to get/set properties and check interrupts.
> +			   There is only one Fn $01 for the device that is used to control
> +			   and query device specific info so we only need to save it
> +			   globally here for later use. */
> +			fn01QueryBaseAddr = rmi_fd.queryBaseAddr;
> +			fn01ControlBaseAddr = rmi_fd.controlBaseAddr;
> +			break;
> +		  default:
> +		    if (rmi_fd.interruptSrcCnt) {
> +			  rfi = kmalloc(sizeof(*rfi), GFP_KERNEL);
> +
> +			  if (!rfi) {
> +			    printk(KERN_ERR "%s: could not allocate memory for function 0x%x\n",
> +				  drvname, rmi_fd.functionNum);
> +			    retval = -ENOMEM;
> +			    goto exit_fail;
> +			  } else {
> +			    INC_ALLOC_STAT(rfi);
> +
> +			    /* Get the ptr to the detect function based on the function number */
> +			    found = false;
> +			    list_for_each_entry(fn, &fns_list, link) {
> +				  /* check if function number matches - if so call that detect function */
> +				  if (fn->functionNum == rmi_fd.functionNum) {
> +				    found = true;
> +				    fn->detect(rpd->app, rfi, &rmi_fd, interruptCount);
> +				  }
> +			    }
> +			    if (!found) {
> +				  printk(KERN_ERR "%s: could not find support for function 0x%x\n",
> +					drvname, rmi_fd.functionNum);
> +			    }
> +			  }
> +		    } else {
> +			  printk(KERN_INFO "%s:   Found Function %02x - Ignored.\n", drvname, rmi_fd.functionNum & 0xff);
> +		    }
> +		    break;
> +		  }
> +
> +	      /* bump interrupt count for next iteration */
> +		  interruptCount += (rmi_fd.interruptSrcCnt & 0x7);
> +
> +		  /* We only want to add functions to the list that have data associated with them. */
> +	      if (rfi && rmi_fd.interruptSrcCnt) {
> +			printk(KERN_INFO "%s: Adding function 0x%x with %d sources. \n", drvname, rfi->functionNum, rfi->numSources);
> +
> +			/* link this function info to the RMI module infos list of functions */
> +			mutex_lock(&rfi_mutex);
> +			list_add_tail(&rfi->link, &rpd->rmi.functions);
> +			mutex_unlock(&rfi_mutex);
> +		  }
> +		} else {
> +		  /* A zero in the function number signals the end of the PDT */
> +		  printk(KERN_INFO "%s:   Found End of PDT\n", drvname);
> +		  break;
> +		}
> +	  } else {
> +		/* failed to read next PDT entry - end PDT scan - this may result
> +		   in an incomplete set of recognized functions - should probably
> +		   return an error but the driver may still be viable for diagnostics
> +		   and debugging so let's let it continue. */
> +		printk(KERN_ERR "%s:   Read Error 0x%x when reading next PDT entry - ending PDT scan.\n", drvname, retval);
> +		break;
> +	  }
> +	}
> +
> +	/* calculate the interrupt register count - used in the ISR to read the correct number of interrupt registers */
> +	interruptRegisterCount = (interruptCount + 7) / 8;
> +
> +	/* Function $01 will be used to query the product properties, and product ID
> +	 * so we had to read the PDT above first to get the Fn $01 query address and
> +	 * prior to filling in the product info. NOTE: Even an unflashed
> +	 * device will still have FN $01.
> +	 */
> +
> +	/* Load up the standard queries and get the RMI4 module info */
> +	retval = rpd->read_multiple(rpd, fn01QueryBaseAddr, std_queries, sizeof(std_queries));
> +	if (retval) {
> +	  printk(KERN_ERR "%s: Fail reading queries\n", drvname);
> +	  retval = -EIO;
> +	  goto exit_fail;
> +	}
> +
> +	rpd->rmi.rmi_maj_ver  = 4; /* Currently supported RMI version is 4.0 */
> +	rpd->rmi.rmi_min_ver  = 0;
> +
> +	/* get manufacturer id, properties, product info, date code, tester id, serial num and product id (name) */
> +	rpd->rmi.mfgid		= std_queries[0];
> +	rpd->rmi.properties   = std_queries[1];
> +
> +	rpd->rmi.prod_info[0] = std_queries[2];
> +	rpd->rmi.prod_info[1] = std_queries[3];
> +
> +	rpd->rmi.date_code[0] = std_queries[4] & 0x1f; /* year - 2001-2032 */
> +	rpd->rmi.date_code[1] = std_queries[5] & 0x0f; /* month - 1-12 */
> +	rpd->rmi.date_code[2] = std_queries[6] & 0x1f; /* day - 1-31 */
> +
> +	rpd->rmi.tester_id	= ((std_queries[7] & 0x7f) << 8) | (std_queries[8] & 0x7f);
> +
> +	rpd->rmi.serial_num   = ((std_queries[9] & 0x7f) << 8) | (std_queries[10] & 0x7f);
> +
> +	memcpy(rpd->rmi.prod_id, &std_queries[11], 10);
> +	rpd->rmi.prod_id[10] = 0;
> +
> +	printk(KERN_INFO "%s: RMI Protocol: %d.%d\n",
> +	  drvname, rpd->rmi.rmi_maj_ver, rpd->rmi.rmi_min_ver);
> +	printk(KERN_INFO "%s: Manufacturer: %d", drvname,
> +	  rpd->rmi.mfgid);
> +
> +	if (rpd->rmi.mfgid == 1) {
> +	  printk(KERN_INFO " (Synaptics)");
> +	}
> +	printk(KERN_INFO "\n");
> +
> +	printk(KERN_INFO "%s: Properties: 0x%x \n", drvname, rpd->rmi.properties);
> +
> +	printk(KERN_INFO "%s: Product Info: 0x%x 0x%x \n", drvname, rpd->rmi.prod_info[0], rpd->rmi.prod_info[1]);
> +
> +	printk(KERN_INFO "%s: Date Code: Year : %d Month: %d Day: %d\n", drvname, rpd->rmi.date_code[0],
> +	  rpd->rmi.date_code[1], rpd->rmi.date_code[2]);
> +
> +	printk(KERN_INFO "%s: Tester ID: %d \n", drvname, rpd->rmi.tester_id);
> +
> +	printk(KERN_INFO "%s: Serial Number: 0x%x \n", drvname, rpd->rmi.serial_num);
> +
> +	printk(KERN_INFO "%s: Product ID: %s\n", drvname, rpd->rmi.prod_id);
> +  }
> +
> +  /* Add physical driver struct to list */
> +  mutex_lock(&phys_drivers_mutex);
> +  list_add_tail(&rpd->drivers, &phys_drivers);
> +  mutex_unlock(&phys_drivers_mutex);
> +
> +  /* Do a probe for any applications that are registered and bind this physical driver to them */
> +  list_for_each_entry(app, &app_drivers, apps) {
> +	/* Only check apps that are not already bound */
> +	if (!app->rpd) {
> +	  match_and_bind(app, rpd);
> +	}
> +  }
> +
> +  pr_debug("Registered phys driver %s\n", rpd->name);
> +  return 0;
> +
> +exit_fail:
> +  return retval;
> +}
> +EXPORT_SYMBOL(rmi_register_phys_driver);
> +
> +int rmi_unregister_phys_driver(struct rmi_phys_driver *rpd)
> +{
> +  if (rpd->app) {
> +	printk(KERN_WARNING "%s: WARNING: unregister of %s while %s still attached\n",
> +	  drvname, rpd->name, rpd->app->name);
> +  }
> +
> +  pr_debug("Unregistering phys driver %s\n", rpd->name);
> +  mutex_lock(&phys_drivers_mutex);
> +  list_del(&rpd->drivers);
> +  mutex_unlock(&phys_drivers_mutex);
> +
> +  return 0;
> +}
> +EXPORT_SYMBOL(rmi_unregister_phys_driver);
> +
> +struct rmi_application *rmi_register_application(const char *name,
> +  void (*attention)(struct rmi_phys_driver *pd, int instance),
> +  int (*probe)(struct rmi_application *app,
> +  const struct rmi_module_info *rmi),
> +  void (*config)(struct rmi_application *app))
> +{
> +  struct rmi_application *app;
> +  struct rmi_phys_driver *rpd;
> +
> +  if (!name) {
> +	printk(KERN_ERR "%s: Application driver must specify a name\n", drvname);
> +	return 0;
> +  }
> +
> +  if (!attention) {
> +	printk(KERN_ERR "%s: Application driver %s must specify attention notifier.\n",
> +	  drvname, name);
> +	return 0;
> +  }
> +
> +  if (!probe) {
> +	printk(KERN_ERR "%s: Application driver %s must specify a probe function.\n",
> +	  drvname, name);
> +	return 0;
> +  }
> +
> +  if (!config) {
> +	printk(KERN_ERR "%s: Application driver %s must specify a config function.\n",
> +	  drvname, name);
> +	return 0;
> +  }
> +
> +  pr_debug("Registering app driver %s\n", name);
> +
> +  app = kmalloc(sizeof(*app), GFP_KERNEL);
> +  if (!app) {
> +	printk(KERN_ERR "%s: Out of memory\n", drvname);
> +	return 0;
> +  }
> +  INC_ALLOC_STAT(app);
> +
> +  app->name	  = name;
> +  app->attention = attention;
> +  app->probe	 = probe;
> +  app->config	= config;
> +  app->rpd	   = 0;
> +
> +  mutex_lock(&app_drivers_mutex);
> +  list_add_tail(&app->apps, &app_drivers);
> +  mutex_unlock(&app_drivers_mutex);
> +
> +  /* Probe for any matches with physical drivers and bind them. */
> +  list_for_each_entry(rpd, &phys_drivers, drivers) {
> +	if (!rpd->app) {
> +	  match_and_bind(app, rpd);
> +	}
> +  }
> +
> +  pr_debug("Registered app driver %s (%p)\n", name, app);
> +
> +  return app;
> +}
> +EXPORT_SYMBOL(rmi_register_application);
> +
> +void rmi_unregister_application(struct rmi_application *app)
> +{
> +  struct rmi_application *tmp;
> +  int found = 0;
> +
> +  if (!app) {
> +	return;
> +  }
> +
> +  pr_debug("Unregistering app driver %s (%p)\n", app->name, app);
> +
> +  list_for_each_entry(tmp, &app_drivers, apps) {
> +	if (tmp == app) {
> +	  found = 1;
> +	  break;
> +	}
> +  }
> +
> +  if (!found) {
> +	printk(KERN_ERR "%s: Removing rmi application %s: not found\n",
> +	  drvname, app->name);
> +	return;
> +  }
> +
> +  if (app->rpd) {
> +	/* Release the phys driver so it can be unloaded. */
> +	module_put(app->rpd->module);
> +	app->rpd->app = 0;
> +  }
> +
> +  list_del(&app->apps);
> +  kfree(app);
> +  DEC_ALLOC_STAT(app);
> +
> +  pr_debug("Unregistered app driver %p\n", app);
> +}
> +EXPORT_SYMBOL(rmi_unregister_application);
> +
> +static int __init mod_init(void)
> +{
> +  int i;
> +  struct rmi_functions_data *rmi4_fn;
> +
> +  printk(KERN_INFO "Register Mapped Interface Data Layer Driver\n");

No need for announcements, kernel boot is noisy enough.

> +
> +  /* Initialize global list of RMI4 Functions that have data sources.
> +	 We need to add all new functions to this list so that we will have pointers
> +	 to their associated functions for init, config, report and detect. See rmi.h
> +	 for more details. The developer will add a new RMI4 function number in the
> +	 array in rmi.h and then add a new file to the build (called rmi_function_XX.c
> +	 where XX is the hex number for the added RMI4 function). The rest should be
> +	 automatic.
> +  */
> +
> +  /* for each function number defined in rmi.h creat a new rmi_function struct and
> +	 initialize the pointers to the servicing functions and then add it into the
> +	 global list for function support.
> +  */
> +  for (i = 0; i < rmi4_num_supported_data_src_fns; i++) {
> +	/* Add new rmi4 function struct to list */
> +	struct rmi_functions *fn = kmalloc(sizeof(*fn), GFP_KERNEL);
> +	if (!fn) {
> +	  printk(KERN_ERR "%s mod_init: could not allocate memory for rmi_function struct for function 0x%x\n",
> +	drvname, rmi4_supported_data_src_functions[i].functionNumber);
> +	  return -ENOMEM;
> +	} else {
> +
> +	  INC_ALLOC_STAT(fn);
> +
> +	  rmi4_fn = &rmi4_supported_data_src_functions[i];
> +	  fn->functionNum = rmi4_fn->functionNumber;
> +	  /* Fill in ptrs to functions. The functions are linked in from a file
> +	 called rmi_function_xx.c where xx is the hex number of the RMI4 function
> +	 from the RMI4 spec. Also, the function prototypes need to be added to
> +	 rmi_function_xx.h - also where xx is the hex number of the RMI4 function.
> +	 So that you don't get compile errors and that new header needs to be
> +	 included in the rmi.h header file.
> +	  */
> +	  fn->report = rmi4_fn->reportFn;
> +	  fn->config = rmi4_fn->configFn;
> +	  fn->init =   rmi4_fn->initFn;
> +	  fn->detect = rmi4_fn->detectFn;
> +
> +	  /* Add the new fn to the global list */
> +	  mutex_lock(&fns_mutex);
> +	  list_add_tail(&fn->link, &fns_list);
> +	  mutex_unlock(&fns_mutex);
> +	}
> +  }
> +
> +  return 0;
> +}
> +
> +static void __exit mod_exit(void)
> +{
> +  struct rmi_application *app, *apptmp;
> +
> +  /* These lists should be empty, but just in case . . . */
> +  mutex_lock(&app_drivers_mutex);
> +  list_for_each_entry_safe(app, apptmp, &app_drivers, apps) {
> +	list_del(&app->apps);
> +	kfree(app);
> +	DEC_ALLOC_STAT(app);
> +  }
> +  mutex_unlock(&app_drivers_mutex);
> +
> +  CHECK_ALLOC_STAT(app);

OK, so overall this module seem to be re-implementing the driver model
already presented in the kernel. Why didn't you simply create "rmi" bus
and rmi_device and rmi_driver on that bus?

> +}
> +
> +/** Specifies to the kernel that the mod_init() function should be called when
> + * the module is loaded.
> + * \see mod_init()
> + */
> +module_init(mod_init);
> +/** Specifies to the kernel that the mod_exit() function should be called when
> + * the module is unloaded.
> + * \see mod_exit()
> + */
> +module_exit(mod_exit);
> +
> +/** Standard driver module information - the author of the module.
> + */
> +MODULE_AUTHOR("Synaptics, Inc.");
> +/** Standard driver module information - a summary description of this module.
> + */
> +MODULE_DESCRIPTION("RMI4 Driver");
> +/** Standard driver module information - the license under which this module
> + * is included in the kernel.
> + */
> +MODULE_LICENSE("GPL");
> +
> +/* vim600: set noexpandtab sw=8 ts=8 : */
> diff --git a/drivers/input/touchscreen/rmi_core.h b/drivers/input/touchscreen/rmi_core.h
> new file mode 100755
> index 0000000..dab4997
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_core.h
> @@ -0,0 +1,59 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) Data Layer Core Header.
> + * Copyright (c) 2007-2009 Synaptics Incorporated.
> + *
> + * \note YOU SHOULD NOT NEED TO INCLUDE THIS FILE FOR PHYSICAL OR APPLICATION
> + * LAYERS.
> + *
> + */
> +/*
> + *
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#ifndef _RMI_CORE_H
> +#define _RMI_CORE_H
> +
> +struct rmi_application {
> +  const char *name;
> +  void (*attention)(struct rmi_phys_driver *pd, int instance);
> +  /** Probe Function
> +   *  This function is called to give the application layer an
> +   *  opportunity to claim an RMI device.  The application layer cannot
> +   *  read RMI registers at this point.  Defer that to the config
> +   *  function call which occurs immediately after a successful probe.
> +   */
> +  int (*probe)(struct rmi_application *app, const struct rmi_module_info *rmi);
> +  /** Config Function
> +   *  This function is called after a successful probe.  It gives the
> +   *  application driver an opportunity to query and/or configure an RMI
> +   *  device before data starts flowing.
> +   */
> +  void (*config)(struct rmi_application *app);
> +  /** Standard kernel linked list implementation.
> +   *  Documentation on how to use it can be found at
> +   *  http://isis.poly.edu/kulesh/stuff/src/klist/.
> +   */
> +  struct list_head apps;
> +  struct rmi_phys_driver *rpd;
> +  int    polling_required;
> +};
> +
> +#endif
> +
> +/* vim600: set noexpandtab sw=8 ts=8 : */
> diff --git a/drivers/input/touchscreen/rmi_function_11.c b/drivers/input/touchscreen/rmi_function_11.c
> new file mode 100755
> index 0000000..d490c21
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_function_11.c
> @@ -0,0 +1,333 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) Function $11 support for 2D.
> + * Copyright (c) 2009 Synaptics Incorporated
> + *
> + * For every RMI4 function that has a data source - like 2D sensors, buttons, LEDs,
> + * GPIOs, etc. - the user will create a new rmi_function_xx.c file and add these
> + * functions to perform the config(), init(), report() and detect() functionality.
> + * The function pointers are then srored under the RMI function info and these
> + * functions will automatically be called by the global config(), init(), report()
> + * and detect() functions that will loop through all data sources and call the
> + * data sources functions using these functions pointed to by the function ptrs.
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/delay.h>
> +#include <linux/kthread.h>
> +#include <linux/freezer.h>
> +#include <linux/input.h>
> +
> +#include "rmi.h"
> +#include "rmi_core.h"
> +#include "rmi_functions.h"
> +
> +extern unsigned short fn01ControlBaseAddr;  /* RMI4 device contorl == function 0x01 */
> +
> +static int sensorMaxX;
> +static int sensorMaxY;
> +
> +/**
> + * This reads in a sample and reports the function $11 source data to the input subsystem.
> + * It is used for both polling and interrupt driven operation. This is called a lot
> + * so don't put in any informational printks since they will slow things way down!
> + */
> +int FN_11_report(struct rmi_application *app, struct rmi_function_info *rfi, struct input_dev *input)
> +{
> +  unsigned char values[2] = {0, 0};
> +  unsigned char data[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
> +  int touch; /* number of touch points - fingers in this case */
> +  int X, Y, Z, W, Wy, Wx;
> +  int finger;
> +  int fn11FingersSupported;
> +  int fn11FingerRegisters;
> +  unsigned short fn11DataBaseAddr;
> +  unsigned char fn11DataRegBlockSize;
> +
> +  touch = 0;
> +
> +  /* get 2D sensor finger data */
> +  /* First get the finger status field - the size of the finger status field is
> +     determined by the number of finger supporte - 2 bits per finger, so the number
> +     of registers to read is : registerCount = ciel(numberOfFingers/4).
> +     Read the required number of registers and check each 2 bit field to determine
> +     if a finger is down (00 = finger not present, 01 = finger present and data accurate,
> +     10 = finger present but data may not be accurate, 11 = reserved for product use).
> +  */
> +  fn11FingersSupported = rfi->numDataPoints;
> +  fn11FingerRegisters = (fn11FingersSupported + 3)/4;
> +
> +  fn11DataBaseAddr = rfi->funcDescriptor.dataBaseAddr;
> +
> +  if (rmi_read_multiple(app, fn11DataBaseAddr, values, fn11FingerRegisters)) {
> +    printk(KERN_ERR "RMI4 function $11 report: Could not read finger status registers 0x%x\n", fn11DataBaseAddr);
> +    return 0;
> +  }
> +
> +  /* For each finger present, read the proper number of registers to get absolute data. */
> +  fn11DataRegBlockSize = rfi->dataRegBlockSize;
> +
> +  for (finger = 0; finger < fn11FingersSupported; finger++) {
> +    int reg;
> +    int fingerShift;
> +    int fingerStatus;
> +
> +    reg = finger/4; /* determine which data byte the finger status is in */
> +    fingerShift = (finger % 4) * 2; /* determine bit shift to get that fingers status */
> +    fingerStatus = (values[reg] >> fingerShift) & 3;
> +
> +    /* if finger status indicates a finger is present then read the finger data and report it */
> +    if (fingerStatus == 1 || fingerStatus == 2) {
> +      touch++; /* number of active touch points not same as number of supported fingers */
> +
> +      /* Read the finger data */
> +      if (rmi_read_multiple(app, fn11DataBaseAddr +
> +	((finger  * fn11DataRegBlockSize) + fn11FingerRegisters), data, fn11DataRegBlockSize)) {
> +		printk(KERN_ERR "RMI4 function $11 report: Could not read finger data registers 0x%x\n",
> +		fn11DataBaseAddr + ((finger  * fn11DataRegBlockSize) + fn11FingerRegisters));
> +		return 0;
> +      } else {
> +		X = (data[0] & 0x1f) << 4;
> +		X |= data[2] & 0xf;
> +		Y = (data[1] & 0x1f) << 4;
> +		Y |= (data[2] >> 4) & 0xf;
> +		W = data[3];
> +
> +	/* upper 4 bits of W are Wy, lower 4 of W are Wx */
> +		Wy =  (W >> 4) & 0x0f;
> +		Wx = W & 0x0f;
> +
> +		Z = data[4];
> +
> +	/* if this is the first finger report normal ABS_X, ABS_Y, PRESSURE, TOOL_WIDTH events for non-MT apps.
> +	   Apps that support Multi-touch will ignore these events and use the MT events. Apps that don't support
> +	   Multi-touch will still function.
> +	*/
> +	if (touch == 1) {
> +	  input_report_abs(input, ABS_X, X);
> +	  input_report_abs(input, ABS_Y, Y);
> +	  input_report_abs(input, ABS_PRESSURE, Z);
> +	  input_report_abs(input, ABS_TOOL_WIDTH, max(Wx, Wy));

BTN_TOUCH for applications not using pressure is nice too.

> +	}
> +
> +	/* Report Multi-Touch events for each finger */
> +	input_report_abs(input, ABS_MT_TOUCH_MAJOR, max(Wx, Wy)); /* major axis of touch area ellipse */
> +	input_report_abs(input, ABS_MT_TOUCH_MINOR, min(Wx, Wy)); /* minor axis of touch area ellipse */
> +	input_report_abs(input, ABS_MT_ORIENTATION, (Wx > Wy ? 1 : 0)); /* Currently only 2 supported - 1 or 0 */
> +	input_report_abs(input, ABS_MT_POSITION_X, X);
> +	input_report_abs(input, ABS_MT_POSITION_Y, Y);
> +	input_report_abs(input, ABS_MT_TRACKING_ID, finger+1); /* Tracking ID reported but not used yet */
> +	input_mt_sync(input); /* MT sync between fingers */
> +      }
> +    }
> +  }
> +
> +  if (touch) /* touch will be non-zero if we had any reported events */
> +    input_sync(input); /* sync after groups of events */
> +
> +  /* return the number of touch points - fingers down or buttons pressed */
> +  return touch;
> +}
> +
> +void FN_11_config(struct rmi_application *app, struct rmi_function_info *rfi)
> +{
> +  /* For the data source - print info and do any source specific configuration. */
> +  unsigned char data[14];
> +
> +  printk(KERN_INFO "RMI4 function $11 config\n");
> +
> +  /* Get and print some info about the data source... */
> +
> +  /*
> +   * To Query 2D devices we need to read from the address obtained
> +   * from the function descriptor stored in the RMI function info.
> +   */
> +  if (rmi_read_multiple(app, rfi->funcDescriptor.queryBaseAddr, data, 9)) {
> +    printk(KERN_ERR "RMI4 function $11 config: Could not read function query registers 0x%x\n", rfi->funcDescriptor.queryBaseAddr);
> +    return;
> +  } else {
> +    printk(KERN_INFO "  Number of Fingers:   %d\n", data[1] & 7);
> +    printk(KERN_INFO "  Is Configurable:     %d\n", data[1] & (1 << 7) ? 1 : 0);
> +    printk(KERN_INFO "  Has Gestures:        %d\n", data[1] & (1 << 5) ? 1 : 0);
> +    printk(KERN_INFO "  Has Absolute:        %d\n", data[1] & (1 << 4) ? 1 : 0);
> +    printk(KERN_INFO "  Has Relative:        %d\n", data[1] & (1 << 3) ? 1 : 0);
> +
> +    printk(KERN_INFO "  Number X Electrodes: %d\n", data[2] & 0x1f);
> +    printk(KERN_INFO "  Number Y Electrodes: %d\n", data[3] & 0x1f);
> +    printk(KERN_INFO "  Maximum Electrodes:  %d\n", data[4] & 0x1f);
> +
> +    printk(KERN_INFO "  Absolute Data Size:  %d\n", data[5] & 3);
> +
> +    printk(KERN_INFO "  Has XY Dist:         %d\n", data[7] & (1 << 7) ? 1 : 0);
> +    printk(KERN_INFO "  Has Pinch:           %d\n", data[7] & (1 << 6) ? 1 : 0);
> +    printk(KERN_INFO "  Has Press:           %d\n", data[7] & (1 << 5) ? 1 : 0);
> +    printk(KERN_INFO "  Has Flick:           %d\n", data[7] & (1 << 4) ? 1 : 0);
> +    printk(KERN_INFO "  Has Early Tap:       %d\n", data[7] & (1 << 3) ? 1 : 0);
> +    printk(KERN_INFO "  Has Double Tap:      %d\n", data[7] & (1 << 2) ? 1 : 0);
> +    printk(KERN_INFO "  Has Tap and Hold:    %d\n", data[7] & (1 << 1) ? 1 : 0);
> +    printk(KERN_INFO "  Has Tap:             %d\n", data[7] & 1 ? 1 : 0);
> +    printk(KERN_INFO "  Has Palm Detect:     %d\n", data[8] & 1 ? 1 : 0);
> +    printk(KERN_INFO "  Has Rotate:          %d\n", data[8] & (1 << 1) ? 1 : 0);

Way yoo noisy... if this is important maybe use debugfs.

> +
> +    if (rmi_read_multiple(app, rfi->funcDescriptor.controlBaseAddr, data, 14)) {
> +      printk(KERN_ERR "RMI4 function $11 config: Could not read function control registers 0x%x\n", rfi->funcDescriptor.controlBaseAddr);
> +      return;
> +    }
> +
> +    /* Store these for use later...*/
> +    sensorMaxX = ((data[6] & 0x1f) << 8) | ((data[7] & 0xff) << 0);
> +    sensorMaxY = ((data[8] & 0x1f) << 8) | ((data[9] & 0xff) << 0);
> +
> +    printk(KERN_INFO "  Sensor Max X:  %d\n", sensorMaxX);
> +    printk(KERN_INFO "  Sensor Max Y:  %d\n", sensorMaxY);
> +  }
> +}
> +
> +/**
> + * Initialize any function $11 specific params and settings - input settings, device settings, etc.
> + */
> +void FN_11_init(struct input_dev *input)
> +{
> +  printk(KERN_INFO "RMI4 function $11 init\n");
> +
> +  /* need to init the input abs params for the 2D */
> +  input->evbit[0] = BIT(EV_ABS);
> +
> +  /* Use the max X and max Y read from the device...*/
> +  input_set_abs_params(input, ABS_X, 0, sensorMaxX, 0, 0);
> +  input_set_abs_params(input, ABS_Y, 0, sensorMaxY, 0, 0);
> +  input_set_abs_params(input, ABS_MT_POSITION_X, 0, sensorMaxX, 0, 0);
> +  input_set_abs_params(input, ABS_MT_POSITION_Y, 0, sensorMaxY, 0, 0);
> +
> +  input_set_abs_params(input, ABS_PRESSURE, 0, 255, 0, 0);
> +  input_set_abs_params(input, ABS_TOOL_WIDTH, 0, 15, 0, 0);
> +
> +  input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 15, 0, 0);
> +  input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 15, 0, 0);
> +  input_set_abs_params(input, ABS_MT_ORIENTATION, 0, 1, 0, 0);
> +  input_set_abs_params(input, ABS_MT_TRACKING_ID, 1, 10, 0, 0);
> +}
> +
> +void FN_11_detect(struct rmi_application *app, struct rmi_function_info *rfi,
> +  struct rmi_function_descriptor *fd, unsigned int interruptCount)
> +{
> +  char fn11Queries[9];
> +  int i;
> +  unsigned short fn11InterruptOffset;
> +  unsigned char fn11AbsDataSize;
> +  unsigned char fn11AbsDataBlockSize;
> +  int fn11HasPinch, fn11HasFlick, fn11HasTap;
> +  int fn11HasTapAndHold, fn11HasDoubleTap;
> +  int fn11HasEarlyTap, fn11HasPress;
> +  int fn11HasPalmDetect, fn11HasRotate;
> +  int fn11HasRel;
> +  unsigned char f11_egr_0, f11_egr_1;
> +  unsigned int fn11AllDataBlockSize;
> +  int retval;
> +
> +  printk(KERN_INFO "RMI4 function $11 detect\n");
> +
> +  /* Store addresses - used elsewhere to read data, control, query, etc. */
> +  rfi->funcDescriptor.queryBaseAddr = fd->queryBaseAddr;
> +  rfi->funcDescriptor.commandBaseAddr = fd->commandBaseAddr;
> +  rfi->funcDescriptor.controlBaseAddr = fd->controlBaseAddr;
> +  rfi->funcDescriptor.dataBaseAddr = fd->dataBaseAddr;
> +  rfi->funcDescriptor.interruptSrcCnt = fd->interruptSrcCnt;
> +  rfi->funcDescriptor.functionNum = fd->functionNum;
> +
> +  rfi->numSources = fd->interruptSrcCnt;
> +
> +  /* need to get number of fingers supported, data size, etc. -
> +     to be used when getting data since the number of registers to
> +     read depends on the number of fingers supported and data size. */
> +  if (rmi_read_multiple(app, fd->queryBaseAddr, fn11Queries, sizeof(fn11Queries))) {
> +    printk(KERN_ERR "RMI4 function $11 detect: Could not read function query registers 0x%x\n", rfi->funcDescriptor.queryBaseAddr);
> +    return;
> +  }
> +
> +  /* 2D data sources have only 3 bits for the number of fingers supported - so the encoding is a bit wierd. */
> +  rfi->numDataPoints = 2; /* default number of fingers supported */
> +  if ((fn11Queries[1] & 0x7) <= 4)
> +   rfi->numDataPoints = (fn11Queries[1] & 0x7) + 1; /* add one since zero based */
> +  else {
> +    if ((fn11Queries[1] & 0x7) == 5) /* a value of 5 is up to 10 fingers - 6 and 7 are reserved (shouldn't get these i int retval;n a normal 2D source). */
> +      rfi->numDataPoints = 10;
> +  }
> +
> +  /* Need to get interrupt info to be used later when handling interrupts. */
> +  rfi->interruptRegister = (interruptCount + 7)/8;
> +
> +  /* loop through interrupts for each source in fn $11 and or in a bit to the interrupt mask for each. */
> +  fn11InterruptOffset = interruptCount % 8;
> +
> +  for (i = fn11InterruptOffset; i < ((fd->interruptSrcCnt & 0x7) + fn11InterruptOffset); i++) {
> +    rfi->interruptMask |= 1 << i;
> +  }
> +
> +  /* Size of just the absolute data for one finger */
> +  fn11AbsDataSize = fn11Queries[5] & 0x03;
> +  fn11AbsDataBlockSize = 3 + (2 * (fn11AbsDataSize == 0 ? 1 : 0)); /* One each for X and Y, one for LSB for X & Y, one for W, one for Z */
> +  rfi->dataRegBlockSize = fn11AbsDataBlockSize;
> +
> +  /* need to determine the size of data to read - this depends on conditions such as
> +     whether Relative data is reported and if Gesture data is reported. */
> +  f11_egr_0 = fn11Queries[7];
> +  f11_egr_1 = fn11Queries[8];
> +
> +  /* Get info about what EGR data is supported, whether it has Relative data supported, etc. */
> +  fn11HasPinch = f11_egr_0 & 0x40;
> +  fn11HasFlick = f11_egr_0 & 0x10;
> +  fn11HasTap = f11_egr_0 & 0x01;
> +  fn11HasTapAndHold = f11_egr_0 & 0x02;
> +  fn11HasDoubleTap = f11_egr_0 & 0x04;
> +  fn11HasEarlyTap = f11_egr_0 & 0x08;
> +  fn11HasPress = f11_egr_0 & 0x20;
> +  fn11HasPalmDetect = f11_egr_1 & 0x01;
> +  fn11HasRotate = f11_egr_1 & 0x02;
> +  fn11HasRel = fn11Queries[1] & 0x08;
> +
> +  /* Size of all data including finger status, absolute data for each finger, relative data and EGR data */
> +  fn11AllDataBlockSize =
> +    /* finger status, four fingers per register */
> +    ((rfi->numDataPoints + 3) / 4) +
> +    /* absolute data, per finger times number of fingers */
> +    (fn11AbsDataBlockSize * rfi->numDataPoints) +
> +    /* two relative registers (if relative is being reported) */
> +    2 * fn11HasRel +
> +    /* F11_2D_Data8 is only present if the egr_0 register is non-zero. */
> +    !!(f11_egr_0) +
> +    /* F11_2D_Data9 is only present if either egr_0 or egr_1 registers are non-zero. */
> +    (f11_egr_0 || f11_egr_1) +
> +    /* F11_2D_Data10 is only present if EGR_PINCH or EGR_FLICK of egr_0 reports as 1. */
> +    !!(fn11HasPinch | fn11HasFlick) +
> +    /* F11_2D_Data11 and F11_2D_Data12 are only present if EGR_FLICK of egr_0 reports as 1. */
> +    2 * !!(fn11HasFlick);
> +
> +  /* Disable Interrupts. It is up to the Application Driver to
> +   * turn them on when it's ready for them. */
> +  retval = rmi_write(app, fn01ControlBaseAddr + 1 + rfi->interruptRegister, 0);
> +  if (!retval) {
> +    printk(KERN_ERR "Function $11 Interrupt Disable Fail: %d\n", retval);
> +  }
> +
> +}
> +
> +/* vim600: set noexpandtab sw=8 ts=8 :*/
> diff --git a/drivers/input/touchscreen/rmi_function_11.h b/drivers/input/touchscreen/rmi_function_11.h
> new file mode 100755
> index 0000000..70de6c6
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_function_11.h
> @@ -0,0 +1,41 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) Function $11 support for 2D.
> + * Copyright (c) 2009 Synaptics Incorporated
> + *
> + * For every RMI4 function that has a data source - like 2D sensors, buttons, LEDs,
> + * GPIOs, etc. - the user will create a new rmi_function_xx.c file and add these
> + * functions to perform the config(), init(), report() and detect() functionality.
> + * The function pointers are then stored under the RMI function info and these
> + * functions will automatically be called by the global config(), init(), report()
> + * and detect() functions that will loop through all data sources and call the
> + * data sources functions using these functions pointed to by the function ptrs.
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +#ifndef _RMI_FUNCTION_11_H
> +#define _RMI_FUNCTION_11_H
> +
> +int  FN_11_report(struct rmi_application *app, struct rmi_function_info *rfi, struct input_dev *input);
> +void FN_11_config(struct rmi_application *app, struct rmi_function_info *rfi);
> +void FN_11_init(struct input_dev *input);
> +void FN_11_detect(struct rmi_application *app, struct rmi_function_info *rfi, struct rmi_function_descriptor *fd, unsigned int interruptCount);
> +
> +#endif
> +
> +/* vim600: set noexpandtab sw=8 ts=8 :*/
> diff --git a/drivers/input/touchscreen/rmi_functions.h b/drivers/input/touchscreen/rmi_functions.h
> new file mode 100644
> index 0000000..dff44c0
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_functions.h
> @@ -0,0 +1,107 @@
> +
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) Functions Definition Header File.
> + * Copyright (c) 2007-2009 Synaptics Incorporated
> + *
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#ifndef _RMI_FUNCTIONS_H
> +#define _RMI_FUNCTIONS_H
> +
> +/* This struct is for creating a list of RMI4 functions that have data sources
> +   associated with them. This is to facilitate adding new support for other
> +   data sources besides 2D sensors.
> +   To add a new data source support, the developer will create a new file
> +   and add these 4 functions below with FN$## in front of the names - where
> +   ## is the hex number for the function taken from the RMI4 specification.
> +
> +   The function number will be associated with this and later will be used to
> +   match the RMI4 function to the 4 functions for that RMI4 function number.
> +
> +   The user will also have to add code that adds the new rmi_functions item
> +   to the global list of RMI4 functions and stores the pointers to the 4 functions
> +   in the function pointers.
> +*/
> +struct rmi_functions {
> +  unsigned char functionNum;
> +
> +  struct input_dev *input;
> +
> +  /* ptrs to function specific functions for report, config, init and detect. */
> +  /* These ptrs. need to be filled in for every RMI4 function that has data
> +     source(s) associated with it - like fn $11 (2D sensors), fn $19 (buttons),
> +     etc. Each RMI4 function that has data sources will be added into a list
> +     that is used to match the function number against the number stored here.
> +  */
> +  int  (*report)(struct rmi_application *app, struct rmi_function_info *rfi, struct input_dev *input);
> +  void (*config)(struct rmi_application *app, struct rmi_function_info *rfi);
> +  void (*init)(struct input_dev *input);
> +  void (*detect)(struct rmi_application *app, struct rmi_function_info *rfi, struct rmi_function_descriptor *fd, unsigned int interruptCount);
> +
> +  /** Standard kernel linked list implementation.
> +   * Documentation on how to use it can be found at
> +   * http://isis.poly.edu/kulesh/stuff/src/klist/.
> +   */
> +  struct list_head link;
> +};
> +
> +
> +/* Each time a new RMI4 function support is added the developer needs to bump the number of
> +   supported data src functions and add the info for that RMI4 function to the array along
> +   with pointers to the report, config, init and detect functions that they coded in rmi_function_xx.c
> +   and rmi_function_xx.h - where xx is the RMI4 function number for the new RMI4 data source function.
> +   The information for the RMI4 functions is obtained from the RMI4 specification document.
> +*/
> +#define rmi4_num_supported_data_src_fns 1
> +
> +/* add hdr files for all prototypes for RMI4 data source functions being supported */
> +#include "rmi_function_11.h"
> +/* #include "rmi_function_19.h" */
> +
> +typedef int(*reportFuncPtr)(struct rmi_application *app, struct rmi_function_info *rfi, struct input_dev *input);
> +typedef void(*configFuncPtr)(struct rmi_application *app, struct rmi_function_info *rfi);
> +typedef void(*initFuncPtr)(struct input_dev *input);
> +typedef void(*detectFuncPtr)(struct rmi_application *app, struct rmi_function_info *rfi, struct rmi_function_descriptor *fd, unsigned int interruptCount);
> +
> +struct rmi_functions_data {
> +  int functionNumber;
> +  reportFuncPtr reportFn;
> +  configFuncPtr configFn;
> +  initFuncPtr initFn;
> +  detectFuncPtr detectFn;
> +};
> +
> +/* NOTE:
>    Developer - add in any new RMI4 fn data info - function number and ptrs to report, config, init and detect functions.
> +   This data is used to point to the functions that need to be called to config, init, detect and report data for the
> +   new RMI4 function. These only need to be added for RMI4 functions that support data source - like 2D sensors, buttons,
> +   LEDs, GPIOs, etc. Refer to the RMI4 specification for information on these RMI4 functions and what data they report.
> +*/
> +
> +struct rmi_functions_data rmi4_supported_data_src_functions[rmi4_num_supported_data_src_fns] = {
> +  /* Fn $11 */
> +  {0x11, FN_11_report, FN_11_config, FN_11_init, FN_11_detect},
> +  /* Fn $19 */
> +  /* {0x19, FN_19_report, FN_19_config, FN_19_init, FN_19_detect), */
> +
> +};
> +
> +#endif
> diff --git a/drivers/input/touchscreen/rmi_i2c.h b/drivers/input/touchscreen/rmi_i2c.h
> new file mode 100755
> index 0000000..8bfacb2
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_i2c.h
> @@ -0,0 +1,57 @@
> +/**
> + * \file
> + * Synaptics RMI over I2C Physical Layer Driver Header File.
> + * Copyright (c) 2007-2009 Synaptics Incorporated
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#ifndef _RMI_I2C_H
> +#define _RMI_I2C_H
> +
> +/** Platform-specific configuration data.
> + * This structure is used by the platform-specific driver to designate
> + * specific information about the hardware.  A platform client may supply
> + * an array of these to the rmi_phys_i2c driver.
> + */
> +struct rmi_i2c_clientdata {
> +	/** The seven-bit i2c address of the device. */
> +	int i2c_address;
> +	/** The number of the irq.  Set to zero if polling is required. */
> +	int irq;
> +	/** The type of the irq (e.g., IRQF_TRIGGER_FALLING).  Only valid if
> +	 * irq != 0 */
> +	int irq_type;
> +	/** Function used to query the state of the attention line.  It always
> +	 * returns 1 for "active" regardless of the polarity of the attention
> +	 * line. */
> +	int (*get_attention)(void);
> +};
> +
> +/** Descriptor structure.
> + * Describes the number of i2c devices on the bus that speak RMI.
> + */
> +struct rmi_i2c_data {
> +	int num_clients;
> +	struct rmi_i2c_clientdata *clientdata;
> +};
> +
> +#endif
> +
> +/* vim600: set noexpandtab sw=8 ts=8 :*/
> diff --git a/drivers/input/touchscreen/rmi_i2c_gta01.c b/drivers/input/touchscreen/rmi_i2c_gta01.c
> new file mode 100755
> index 0000000..598851d
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_i2c_gta01.c
> @@ -0,0 +1,125 @@
> +/**
> + * \file
> + * Synaptics RMI4 Support for I2C the OpenMoko phone (GTA01) hardware platform.
> + * Copyright (c) 2007-2009 Synaptics, Inc.
> + *
> + * To support a different device - for example if the GPIOs are different or
> + * different hardware is being used - make a copy of this file and change the
> + * name to reflect the new hardware platform then modify it to support the new
> + * platforms hardware (interrupts, IC chip, etc.).
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#include <linux/module.h>
> +#include <linux/jiffies.h>
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <asm/gpio.h>
> +#include "rmi_i2c.h"
> +
> +/* Set this to either 1 or 0 depending on your clearpad hardware. */
> +#define ATTENTION_ACTIVE_LOW 1
> +
> +#if ATTENTION_ACTIVE_LOW
> +#   define IRQ_TRIGGER IRQF_TRIGGER_FALLING
> +#else
> +#   define IRQ_TRIGGER IRQF_TRIGGER_RISING
> +#endif
> +
> +#define GPF3 S3C2410_GPF3
> +#define GPF3INT3 S3C2410_GPF3_EINT3
> +#define IRQINT3 IRQ_EINT3
> +
> +#define GPIO_CFG s3c2410_gpio_cfgpin(S3C2410_GPF3, S3C2410_GPF3_EINT3)
> +
> +static int
> +get_attention(void)
> +{
> +#if ATTENTION_ACTIVE_LOW
> +	return gpio_get_value_cansleep(GPF3) ? 0 : 1;
> +#else
> +	return gpio_get_value_cansleep(GPF3) ? 1 : 0;
> +#endif
> +}
> +
> +static struct rmi_i2c_clientdata rmi_test_clientdata[] = {
> +  [0] = {
> +    .i2c_address   = 0x20,
> +    .irq           = IRQINT3,
> +    .irq_type      = IRQ_TRIGGER,
> +    .get_attention = get_attention,
> +  },
> +};
> +
> +static struct rmi_i2c_data rmi_client_data = {
> +  .num_clients = ARRAY_SIZE(rmi_test_clientdata),
> +  .clientdata  = rmi_test_clientdata,
> +};
> +
> +static void
> +rmi_i2c_release(struct device *dev)
> +{
> +	struct platform_device *pd = container_of(dev, struct platform_device, dev);
> +
> +	kfree(pd);
> +}
> +
> +static struct platform_device *gta01_rmi_device;
> +
> +/*
> + * These are the module insert and remove functions.
> + */
> +static int __init
> +mod_init(void)
> +{
> +	struct platform_device *pd;
> +
> +	printk(KERN_INFO "GTA01 RMI4 Platform Driver Init.\n");
> +
> +	gta01_rmi_device = pd = kmalloc(sizeof(*pd), GFP_KERNEL);

kzalloc. Or even better platform_device_alloc().

> +	if (!pd)
> +		return -ENOMEM;
> +	memset(pd, 0, sizeof(*pd));
> +
> +	/* Set up the GPIO for interrupts */
> +	GPIO_CFG;
> +
> +	pd->name              = "rmi4-i2c";
> +	pd->id                = -1;
> +	pd->dev.platform_data = &rmi_client_data;
> +	pd->dev.release       = rmi_i2c_release;
> +
> +	return platform_device_register(pd);

I do not see why this module is needed - there is no corresponding
platform driver.

> +}
> +
> +static void __exit
> +mod_exit(void)
> +{
> +	return platform_device_unregister(gta01_rmi_device);
> +}
> +
> +MODULE_AUTHOR("Synaptics, Inc.");
> +MODULE_DESCRIPTION("GTA01 (OpenMoko Phone) RMI4 over I2C Device Configuration");
> +MODULE_LICENSE("GPL");
> +
> +module_init(mod_init);
> +module_exit(mod_exit);
> +
> +/* vim600: set noexpandtab sw=8 ts=8 : */
> diff --git a/drivers/input/touchscreen/rmi_phys_i2c.c b/drivers/input/touchscreen/rmi_phys_i2c.c
> new file mode 100755
> index 0000000..8ab1576
> --- /dev/null
> +++ b/drivers/input/touchscreen/rmi_phys_i2c.c
> @@ -0,0 +1,555 @@
> +/**
> + * \file
> + * Synaptics Register Mapped Interface (RMI4) I2C Physical Layer Driver.
> + * Copyright (c) 2007-2009, Synaptics Incorporated
> + *
> + */
> +/*
> + * This file is licensed under the GPL2 license.
> + *
> + *#############################################################################
> + * GPL
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> + * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> + * for more details.
> + *
> + *#############################################################################
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include "rmi_i2c.h"
> +#include "rmi.h"
> +
> +#define DRIVER_NAME	"rmi4_i2c"
> +
> +/** Used to lock access to the page address.
> + * \see rmi_set_page()
> + */
> +static DEFINE_MUTEX(page_mutex);
> +
> +/** This is a count of how many clients are accessing this driver.
> + */
> +static int num_clients;
> +static struct rmi_i2c_clientdata *clientdata;
> +
> +static const struct i2c_device_id rmi_i2c_id_table[] = {
> +	{ DRIVER_NAME, 0 },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(i2c, rmi_i2c_id_table);
> +
> +static struct i2c_driver rmi_i2c_driver;
> +
> +/**
> + * This is the data kept on a per instance (client) basis.  This data is
> + * always accessible by using the container_of() macro of the various elements
> + * inside.
> + */
> +struct instance_data {
> +	int instance_no;
> +	int irq;
> +	struct rmi_phys_driver rpd;
> +	struct i2c_client i2cclient;
> +	int page;
> +	int (*get_attention)(void);
> +};
> +
> +/**
> + * RMI devices have 16-bit addressing, but some of the physical
> + * implementations (like SMBus) only have 8-bit addressing.  So RMI implements
> + * a page address at 0xff of every page so we can reliable page addresses
> + * every 256 registers.  This function sets the page.
> + * \pre The page_mutex lock must be held when this function is entered.
> + * \param[in] id TBD
> + * \param[in] page The new page address.
> + * \return zero on success, non-zero on failure.
> + */
> +int
> +rmi_set_page(struct instance_data *id, unsigned int page)
> +{
> +	char txbuf[2];
> +	int retval;
> +	txbuf[0] = 0xff;
> +	txbuf[1] = page;
> +	retval = i2c_master_send(&id->i2cclient, txbuf, 2);
> +	if (retval != 2) {
> +		printk(KERN_ERR "rmi_i2c: Set page fail: %d\n", retval);
> +	} else {
> +		retval = 0;
> +		id->page = page;
> +	}
> +	return retval;
> +}
> +
> +/**
> + * Read a single register through i2c.
> + * \param[in] pd TBD
> + * \param[in] address The address at which to start the data read.
> + * \param[out] valp Pointer to the buffer where the data will be stored.
> + * \return xero upon success (with the byte read in valp), non-zero upon error.
> + */
> +static int
> +rmi_i2c_read(struct rmi_phys_driver *pd, unsigned short address, char *valp)
> +{
> +	struct instance_data *id = container_of(pd, struct instance_data, rpd);
> +	char txbuf[2];
> +	int retval = 0;
> +	int retry_count = 0;
> +
> +	/* Can't have anyone else changing the page behind our backs */
> +	mutex_lock(&page_mutex);
> +
> +	if (((address >> 8) & 0xff) != id->page) {
> +		/* Switch pages */
> +		retval = rmi_set_page(id, ((address >> 8) & 0xff));
> +		if (retval) {
> +			goto exit;
> +		}
> +	}
> +
> +retry:
> +	txbuf[0] = address & 0xff;
> +	retval = i2c_master_send(&id->i2cclient, txbuf, 1);
> +
> +	if (retval != 1) {
> +		printk(KERN_ERR "rmi_i2c.rmi_i2c_read: Write fail: %d\n",
> +			retval);
> +		goto exit;
> +	}
> +	retval = i2c_master_recv(&id->i2cclient, txbuf, 1);
> +
> +	if (retval != 1) {
> +		if (++retry_count == 5) {
> +			printk(KERN_ERR "rmi_i2c.rmi_i2c_read: "
> +				"Read of 0x%04x fail: %d\n", address, retval);
> +		} else {
> +			mdelay(10);
> +			rmi_set_page(id, ((address >> 8) & 0xff));
> +			goto retry;
> +		}
> +	} else {
> +		retval = 0;
> +		*valp = txbuf[0];
> +	}
> +exit:
> +	mutex_unlock(&page_mutex);
> +	return retval;
> +}
> +
> +/**
> + * Same as rmi_i2c_read, except that multiple bytes are allowed to be read.
> + * \param[in] pd TBD
> + * \param[in] address The address at which to start the data read.
> + * \param[out] valp Pointer to the buffer where the data will be stored.  This
> + * buffer must be at least size bytes long.
> + * \param[in] size The number of bytes to be read.
> + * \return zero upon success (with the byte read in valp), non-zero upon error.
> + * \see rmi_i2c_read()
> + */
> +static int
> +rmi_i2c_read_multiple(struct rmi_phys_driver *pd, unsigned short address,
> +	char *valp, int size)
> +{
> +	struct instance_data *id = container_of(pd, struct instance_data, rpd);
> +	char txbuf[2];
> +	int retval = 0;
> +	int retry_count = 0;
> +
> +	/* Can't have anyone else changing the page behind our backs */
> +	mutex_lock(&page_mutex);
> +
> +	if (((address >> 8) & 0xff) != id->page) {
> +		/* Switch pages */
> +		retval = rmi_set_page(id, ((address >> 8) & 0xff));
> +		if (retval) {
> +			goto exit;
> +		}
> +	}
> +
> +retry:
> +	txbuf[0] = address & 0xff;
> +	retval = i2c_master_send(&id->i2cclient, txbuf, 1);
> +
> +	if (retval != 1) {
> +		printk(KERN_ERR "rmi_i2c.rmi_i2c_read: Write fail: %d\n",
> +			retval);
> +		goto exit;
> +	}
> +	retval = i2c_master_recv(&id->i2cclient, valp, size);
> +
> +	if (retval != size) {
> +		if (++retry_count == 5) {
> +			printk(KERN_ERR "rmi_2ic.rmi_i2c_read_multiple: "
> +				"Read of 0x%04x size %d fail: %d\n",
> +				address, size, retval);
> +		} else {
> +			mdelay(10);
> +			rmi_set_page(id, ((address >> 8) & 0xff));
> +			goto retry;
> +		}
> +	} else {
> +		retval = 0;
> +	}
> +exit:
> +	mutex_unlock(&page_mutex);
> +	return retval;
> +}
> +
> +
> +/**
> + * Write a single register through i2c.
> + * You can write multiple registers at once, but I made the functions for that
> + * seperate for performance reasons.  Writing multiple requires allocation and
> + * freeing.
> + * \param[in] pd TBD
> + * \param[in] address The address at which to start the write.
> + * \param[in] data The data to be written.
> + * \return one upon success, something else upon error.
> + */
> +static int
> +rmi_i2c_write(struct rmi_phys_driver *pd, unsigned short address, char data)
> +{
> +	struct instance_data *id = container_of(pd, struct instance_data, rpd);
> +	unsigned char txbuf[2];
> +	int retval = 0;
> +
> +	/* Can't have anyone else changing the page behind our backs */
> +	mutex_lock(&page_mutex);
> +
> +	if (((address >> 8) & 0xff) != id->page) {
> +		/* Switch pages */
> +		retval = rmi_set_page(id, ((address >> 8) & 0xff));
> +		if (retval) {
> +			goto exit;
> +		}
> +	}
> +
> +	txbuf[0] = address & 0xff;
> +	txbuf[1] = data;
> +	retval = i2c_master_send(&id->i2cclient, txbuf, 2);
> +
> +	if (retval != 2) {
> +		printk(KERN_ERR "rmi_i2c.rmi_i2c_write: Write fail: %d\n",
> +			retval);
> +		goto exit; /* Leave this in case we add code below */
> +	}
> +exit:
> +	mutex_unlock(&page_mutex);
> +	return retval;
> +}
> +
> +/**
> + * Write multiple registers.
> + * \param[in] pd TBD
> + * \param[in] address The address at which to start the write.
> + * \param[in] valp A pointer to a buffer containing the data to be written.
> + * \param[in] size The number of bytes to write.
> + * \return one upon success, something else upon error.
> + */
> +static int
> +rmi_i2c_write_multiple(struct rmi_phys_driver *pd, unsigned short address,
> +	char *valp, int size)
> +{
> +	struct instance_data *id = container_of(pd, struct instance_data, rpd);
> +	unsigned char *txbuf;
> +	unsigned char txbuf_most[16];
> +	int retval = 0;
> +
> +	if (size < 15) {
> +		/* Avoid an allocation if we can help it. */
> +		txbuf = txbuf_most;
> +	} else {
> +		txbuf = kmalloc(size + 1, GFP_KERNEL);
> +		if (!txbuf)
> +		  return -ENOMEM;
> +	}
> +
> +	/* Yes, it stinks here that we have to copy the buffer */
> +	{
> +		int i;
> +		for (i = 0; i < size; i++) {
> +			txbuf[i + 1] = valp[i];
> +		}
> +	}
> +
> +	/* Can't have anyone else changing the page behind our backs */
> +	mutex_lock(&page_mutex);
> +
> +	if (((address >> 8) & 0xff) != id->page) {
> +		/* Switch pages */
> +		retval = rmi_set_page(id, ((address >> 8) & 0xff));
> +		if (retval) {
> +			goto exit;
> +		}
> +	}
> +
> +	txbuf[0] = address & 0xff;
> +	retval = i2c_master_send(&id->i2cclient, txbuf, size + 1);
> +
> +	if (retval != 1) {
> +		printk(KERN_ERR "rmi_i2c.rmi_i2c_read: Write fail: %d\n", retval);
> +		goto exit;
> +	}
> +exit:
> +	mutex_unlock(&page_mutex);
> +	if (txbuf != txbuf_most)
> +	  kfree(txbuf);
> +	return retval;
> +}
> +
> +/** Get the state of the attention line.
> + * This function returns 1 for an active attention regardless of the
> + * polarity of the ATTN signal.  If the get_attention function of the instance
> + * is not available (probably because ATTN is not implemented), then it always
> + * returns inactive.
> + */
> +static int
> +rmi_i2c_get_attention(struct rmi_phys_driver *rpd)
> +{
> +	struct instance_data *id = container_of(rpd, struct instance_data, rpd);
> +	if (id->get_attention) {
> +		return id->get_attention();
> +	} else {
> +		return 0; /* return inactive */
> +	}
> +}
> +
> +/**
> + * This is the Interrupt Service Routine.  It just notifies the application
> + * layer that attention is required.
> + *
> + * This is a work in progress.  It has yet to be figured out how the interrupt
> + * should be disabled/enabled for interrupt-driven platforms.
> + */
> +static irqreturn_t
> +i2c_attn_isr(int irq, void *info)
> +{
> +	struct instance_data *id = info;
> +	if (id->rpd.attention) {
> +		id->rpd.attention(&id->rpd, id->instance_no);
> +	}
> +	return IRQ_HANDLED;
> +}
> +
> +
> +/**
> + * This function detects each device on the i2c bus and sets up the structures
> + * for it.
> + */
> +static int
> +rmi_i2c_detect(struct i2c_client *client, struct i2c_board_info *board)
> +{
> +	struct instance_data *id;
> +	int retval;
> +	int i;
> +
> +	pr_debug("rmi_i2c: Detect: address = %08x\n", board->addr);
> +
> +	id = kmalloc(sizeof(*id) * 2, GFP_KERNEL);
> +	if (!id) {
> +		printk(KERN_ERR "rmi_i2c: Out of memory\n");
> +		return -ENOMEM;
> +	}
> +
> +	memset(id, 0, sizeof(*id));

Kzalloc.

> +
> +	id->rpd.name           = DRIVER_NAME;
> +	id->rpd.write          = rmi_i2c_write;
> +	id->rpd.read           = rmi_i2c_read;
> +	id->rpd.write_multiple = rmi_i2c_write_multiple;
> +	id->rpd.read_multiple  = rmi_i2c_read_multiple;
> +	id->rpd.get_attention  = rmi_i2c_get_attention;
> +	id->rpd.module         = THIS_MODULE;
> +	id->page               = 0xffff;    /* So we set the page correctly the first time */
> +
> +	/* "Attach" the i2c client to the i2c adapter */
> +	id->i2cclient.addr    = board->addr;
> +	id->i2cclient.driver  = &rmi_i2c_driver;
> +	strlcpy(id->i2cclient.name, "rmi_i2c", I2C_NAME_SIZE);
> +	i2c_set_clientdata(&id->i2cclient, id);
> +
> +	/* Loop through the client data and locate the one that was found. */
> +	for (i = 0; i < num_clients; i++) {
> +		if (board->addr == clientdata[i].i2c_address) {
> +			id->instance_no = i;
> +			id->get_attention = clientdata[i].get_attention;
> +			/*
> +			 * Determine if we need to poll (inefficient) or use
> +			 * interrupts.
> +			 */
> +			if (clientdata[i].irq) {
> +				int irqtype;
> +
> +				id->irq = clientdata[i].irq;
> +				switch (clientdata[i].irq_type) {
> +				case IORESOURCE_IRQ_HIGHEDGE:
> +					irqtype = IRQF_TRIGGER_RISING;
> +					break;
> +				case IORESOURCE_IRQ_LOWEDGE:
> +					irqtype = IRQF_TRIGGER_FALLING;
> +					break;
> +				case IORESOURCE_IRQ_HIGHLEVEL:
> +					irqtype = IRQF_TRIGGER_HIGH;
> +					break;
> +				case IORESOURCE_IRQ_LOWLEVEL:
> +					irqtype = IRQF_TRIGGER_LOW;
> +					break;
> +				default:
> +					printk(KERN_WARNING "rmi_i2c: Invalid IRQ flags in "
> +						"platform data\n");
> +					kfree(id);
> +					return -ENXIO;
> +				}
> +
> +				retval = request_irq(id->irq, i2c_attn_isr,
> +						  IRQF_DISABLED | irqtype, "rmi_i2c", id);
> +				if (retval) {
> +					printk(KERN_WARNING "rmi_i2c: Unable to get attn "
> +					  "irq %d.  Reverting to polling.\n",
> +					  id->irq);
> +					goto do_polling;
> +				}
> +				pr_debug("rmi_i2c: got irq\n");
> +				id->rpd.polling_required = 0;
> +			} else {
> +do_polling:
> +				id->rpd.polling_required = 1;
> +				printk(KERN_INFO "rmi_i2c: No IRQ info given. "
> +					"Polling required.\n");
> +			}
> +
> +			/* We found it, so exit the loop */
> +			break;
> +		}
> +	}
> +


Umm, I really doubt this whole function is correct. Please CC Jean
Delvare <khali@...ux-fr.org> for further i2c bits review.

> +	retval = rmi_register_phys_driver(&id->rpd);
> +	if (retval) {
> +		printk(KERN_ERR "rmi_i2c : Failed to Register %s phys driver\n", id->rpd.name);
> +
> +		if (id->irq) {
> +			free_irq(id->irq, id);
> +		}
> +		kfree(id);
> +		return retval;
> +	}
> +
> +	printk(KERN_INFO "rmi_i2c : Successfully Registered %s phys driver\n", id->rpd.name);
> +
> +	rmi_set_page(id, 0x04);

Why set page is done here?

> +
> +	return 0;
> +}
> +
> +
> +/**
> + * The Driver probe function.  We just tell the i2c subsystem about
> + * ourselves in this call.
> + */
> +static int
> +rmi_i2c_probe(struct i2c_client *client, const struct i2c_device_id *dev_id)
> +{
> +	pr_debug("Probing i2c RMI device\n");
> +
> +	pr_debug("Calling i2c_add_driver\n");
> +	return i2c_add_driver(&rmi_i2c_driver);

I have no idea what this code tires to do... rmi_i2c_probe is probe()
methid of rmi_i2c_driver.... which tries to register rmi_i2c_driver
again????

> +}
> +
> +/**
> + * The Driver remove function.  We tear down the instance data and unregister the phys driver
> + * in this call.
> + */
> +static int
> +rmi_i2c_remove(struct i2c_client *client)
> +{
> +	struct instance_data *id =
> +		container_of(client, struct instance_data, i2cclient);

You normally attach instance data with i2c_{get|set}_clientdata().

> +
> +	/* flush_scheduled_work(); */
> +
> +	pr_debug("Unregistering phys driver %s\n", id->rpd.name);
> +
> +	rmi_unregister_phys_driver(&id->rpd);
> +
> +	pr_debug("Unregistered phys driver %s\n", id->rpd.name);
> +
> +	if (id->irq) {
> +		free_irq(id->irq, id);
> +	}
> +
> +	kfree(id);
> +	pr_debug("remove successful\n");
> +
> +	return 0;
> +}
> +
> +/**
> + * This structure tells the i2c subsystem about us.
> + */
> +static struct i2c_driver rmi_i2c_driver = {
> +	.driver = {
> +		.name  = DRIVER_NAME,
> +		.owner = THIS_MODULE,
> +	},
> +	.probe = rmi_i2c_probe,
> +		.detect = rmi_i2c_detect,

Bad indent.

> +	.remove = rmi_i2c_remove,
> +	.id_table = rmi_i2c_id_table,
> +};
> +
> +/** Print an informational message to the kernel
> + * log and register ourselves with the Platform Driver Subsystem.
> + * This will be called when the module is inserted.
> + * \return the result of our call to platform_driver_register()

You do not call platform_driver_register() anywhere.

> + */
> +static int __init mod_init(void)
> +{
> +	printk(KERN_INFO "RMI I2C Driver\n");
> +	if (RMI_ALLOC_STATS) {
> +		printk(KERN_INFO "    Allocation Stats Enabled\n");
> +	}
> +
> +	return i2c_add_driver(&rmi_i2c_driver);
> +}
> +
> +/** Un-register ourselves from the Platform Driver Subsystem.
> + * This will be called when the module is removed.
> + */
> +static void __exit mod_exit(void)
> +{
> +	i2c_del_driver(&rmi_i2c_driver);
> +}
> +
> +/** Standard driver module information - the author of the module.
> + */
> +MODULE_AUTHOR("Synaptics, Inc.");
> +/** Standard driver module information - a summary description of this module.
> + */
> +MODULE_DESCRIPTION("RMI4 Driver I2C Physical Layer");
> +/** Standard driver module information - the license under which this module
> + * is included in the kernel.
> + */
> +MODULE_LICENSE("GPL");
> +
> +/** Specifies to the kernel that the mod_init() function should be called when
> + * the module is loaded.
> + * \see mod_init()
> + */
> +module_init(mod_init);
> +/** Specifies to the kernel that the mod_exit() function should be called when
> + * the module is unloaded.
> + * \see mod_exit()
> + */
> +module_exit(mod_exit);
> +
> +/* vim600: set noexpandtab sw=8 ts=8 :*/

-- 
Dmitry
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