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Message-ID: <513131B4.6050306@gmail.com>
Date: Sat, 02 Mar 2013 09:54:44 +1100
From: Ryan Mallon <rmallon@...il.com>
To: Michail Kurachkin <michail.kurachkin@...mwad.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Kuten Ivan <Ivan.Kuten@...mwad.com>,
"benavi@...vell.com" <benavi@...vell.com>,
Palstsiuk Viktar <Viktar.Palstsiuk@...mwad.com>,
Dmitriy Gorokh <dmitriy.gorokh@...mwad.com>,
Oliver Neukum <oneukum@...e.de>
Subject: Re: [PATCH v2 01/11] staging: Initial commit of TDM core
On 01/03/13 21:50, Michail Kurachkin wrote:
> From: Michail Kurochkin <michail.kurachkin@...mwad.com>
>
> Signed-off-by: Michail Kurochkin <michail.kurachkin@...mwad.com>
Hi Michail,
Quick review below. I'll try to find some time to look through
the other patches later.
~Ryan
> ---
> drivers/staging/Kconfig | 4 +
> drivers/staging/Makefile | 4 +-
> drivers/staging/tdm/Kconfig | 38 ++
> drivers/staging/tdm/Makefile | 19 +
> drivers/staging/tdm/tdm.h | 292 ++++++++++++++
> drivers/staging/tdm/tdm_core.c | 826 ++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 1182 insertions(+), 1 deletions(-)
> create mode 100644 drivers/staging/tdm/Kconfig
> create mode 100644 drivers/staging/tdm/Makefile
> create mode 100644 drivers/staging/tdm/tdm.h
> create mode 100644 drivers/staging/tdm/tdm_core.c
>
> diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
> index 329bdb4..9bba991 100644
> --- a/drivers/staging/Kconfig
> +++ b/drivers/staging/Kconfig
> @@ -26,6 +26,10 @@ if STAGING
>
> source "drivers/staging/et131x/Kconfig"
>
> +source "drivers/staging/si3226x/Kconfig"
> +
> +source "drivers/staging/tdm/Kconfig"
> +
> source "drivers/staging/slicoss/Kconfig"
>
> source "drivers/staging/usbip/Kconfig"
> diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
> index c7ec486..a7f3699 100644
> --- a/drivers/staging/Makefile
> +++ b/drivers/staging/Makefile
> @@ -1,4 +1,4 @@
> -# Makefile for staging directory
> + # Makefile for staging directory
>
> # fix for build system bug...
> obj-$(CONFIG_STAGING) += staging.o
> @@ -7,6 +7,8 @@ obj-y += media/
> obj-y += net/
> obj-$(CONFIG_ET131X) += et131x/
> obj-$(CONFIG_SLICOSS) += slicoss/
> +obj-$(CONFIG_SI3226X) += si3226x/
> +obj-$(CONFIG_TDM) += tdm/
> obj-$(CONFIG_USBIP_CORE) += usbip/
> obj-$(CONFIG_W35UND) += winbond/
> obj-$(CONFIG_PRISM2_USB) += wlan-ng/
> diff --git a/drivers/staging/tdm/Kconfig b/drivers/staging/tdm/Kconfig
> new file mode 100644
> index 0000000..77b08fb4
> --- /dev/null
> +++ b/drivers/staging/tdm/Kconfig
> @@ -0,0 +1,38 @@
> +#
> +# TDM driver configuration
> +#
> +menuconfig TDM
> + bool "TDM support"
> + depends on HAS_IOMEM
> + help
> + Time-division multiplexing (TDM) is a type of digital (or rarely analog)
> + multiplexing in which two or more bit streams or signals are
> + transferred apparently simultaneously as sub-channels in one
> + communication channel, but are physically taking turns on the
> + channel. The time domain is divided into several recurrent
> + timeslots of fixed length, one for each sub-channel. A sample
> + byte or data block of sub-channel 1 is transmitted during timeslot 1,
> + sub-channel 2 during timeslot 2, etc. One TDM frame consists of one
> + timeslot per sub-channel plus a synchronization channel and
> + sometimes error correction channel before the synchronization.
> +
> +if TDM
> +
> +config TDM_DEBUG
> + bool "Debug support for TDM drivers"
> + depends on DEBUG_KERNEL
> + help
> + Say "yes" to enable debug messaging (like dev_dbg and pr_debug),
> + sysfs, and debugfs support in TDM controller and protocol drivers.
> +
> +
> +comment "TDM controllers"
> +
> +config TDM_KIRKWOOD
> +# TODO: add depend on kirkwood architecture
> +# depends on ARCH_KIRKWOOD
> + tristate "Marvel Kirkwood TDM Controller"
> + help
> + This selects a driver for the Marvel Kirkwood TDM Controller.
> +
> +endif # TDM
> diff --git a/drivers/staging/tdm/Makefile b/drivers/staging/tdm/Makefile
> new file mode 100644
> index 0000000..f99ab5a
> --- /dev/null
> +++ b/drivers/staging/tdm/Makefile
> @@ -0,0 +1,19 @@
> +#
> +# Makefile for kernel TDM drivers.
> +#
> +
> +ccflags-$(CONFIG_TDM_DEBUG) := -DDEBUG
> +
> +# small core, mostly translating board-specific
> +# config declarations into driver model code
> +obj-$(CONFIG_TDM) += tdm_core.o
> +
> +# TDM controller drivers (bus)
> +obj-$(CONFIG_TDM_KIRKWOOD) += kirkwood_tdm.o
> +
> +# ... add above this line ...
> +
> +# TDM protocol drivers (device/link on bus)
> +#obj-$(CONFIG_TDM_TDMDEV) += tdmdev.o
> +# ... add above this line ...
> +
> diff --git a/drivers/staging/tdm/tdm.h b/drivers/staging/tdm/tdm.h
> new file mode 100644
> index 0000000..ee7b5bf
> --- /dev/null
> +++ b/drivers/staging/tdm/tdm.h
> @@ -0,0 +1,292 @@
> +/*
> + * tdm_base.h
> + *
> + * Created on: 20.01.2012
> + * Author: Michail Kurochkin
> + */
> +
> +#ifndef TDM_BASE_H_
> +#define TDM_BASE_H_
> +
> +#include <linux/device.h>
> +
> +extern struct bus_type tdm_bus_type;
> +
> +
> +
Nitpick - Please just leave a single blank line between functions,
globals, etc. Same applies in many other places.
> +/**
> + * General hardware TDM settings
> + */
> +struct tdm_controller_hw_settings {
> + u8 fs_freq; /* Frequency of discretization for audio transport. Normally 8KHz. */
> + u8 count_time_slots; /* Total count of time slots in frame. One time slot = 8bit */
> + u8 channel_size; /* Sample size (in time slots). 1 or 2 time slots. */
> +
> + /* Controller generate PCLK clock - TDM_CLOCK_OUTPUT, */
> + /* or clock generate remote device - TDM_CLOCK_INPUT */
> +#define TDM_CLOCK_INPUT 0
> +#define TDM_CLOCK_OUTPUT 1
> + u8 clock_direction; /* Drirection for PCLK */
> + u8 fs_clock_direction; /* Drirection for FS */
These could be:
bool clock_is_out;
bool fs_clock_is_out;
and then remove the defines?
> +
> + /* FS and data polarity. Detection on rise or fall */
> +#define TDM_POLAR_NEGATIVE 0
> +#define TDM_POLAR_POSITIV 1
> + u8 fs_polarity;
> + u8 data_polarity;
Same here:
bool fs_polarity_negative;
bool data_polarity_negative;
?
> +
> + struct mbus_dram_target_info *dram;
> +};
> +
> +
> +/*
> + * Voice channel
> + */
> +struct tdm_voice_channel {
> + u8 channel_num; /* Hardware channel number */
> + u8 mode_wideband; /* 1 - support wideband mode for current voice channel */
> + u8 tdm_channel; /* TDM channel on registered voice channel */
> + u8 buffer_len; /* Length of transmit and receive buffers */
> + void *private_data; /* hardware dependency channel private data */
> +
> + /* wait queue for transmit and receive operations */
> + wait_queue_head_t tx_queue;
> + wait_queue_head_t rx_queue;
> +
> + struct list_head list; /* Union all tdm voice channels by one controller */
Indentation is messed here. Same is true in a few other places. Running
through checkpatch should point them all out.
> + struct device *dev; /* device requested voice channel */
> +};
> +
> +
> +/**
> + * Remote device connected to TDM bus
> + */
> +struct tdm_device {
> + struct device dev; /* device connected to TDM bus */
> + struct tdm_controller *controller; /* controller attendant TDM bus */
> + u8 tdm_channel_num; /* requested TDM channel number on TDM frame */
> + u16 buffer_sample_count; /* count samples for tx and rx buffers */
> + u8 mode_wideband; /* quality mode 1 or 0. Wideband mode demand is 16bit tdm channel size */
> + struct tdm_voice_channel *ch; /* requested voice channel */
> + char modalias[32];
> +};
> +
> +
> +/**
> + * Driver remote device connected to TDM bus
> + */
> +struct tdm_driver {
> + int (*probe)(struct tdm_device *tdm_dev);
> + int (*remove)(struct tdm_device *tdm_dev);
> + void (*shutdown)(struct tdm_device *tdm_dev);
> + int (*suspend)(struct tdm_device *tdm_dev, pm_message_t mesg);
> + int (*resume)(struct tdm_device *tdm_dev);
> + struct device_driver driver;
> +};
> +
> +
> +/**
> + * TDM controller device
> + */
> +struct tdm_controller {
> + struct device dev;
> + spinlock_t lock;
A comment explaining what fields the lock protects would be nice.
> +
> + struct list_head list; /* Union all TDM controllers */
> +
> + s16 bus_num; /* Number of controller, use -1 for auto numeration */
Do you really need to use fixed width types for some of these values?
Generally fixed width types should only be used for things which map
directly to the hardware, otherwise it is fine to use int here.
> +
> +/* struct tdm_voice_channel *voice_channels; // Hardware or software voice channels transport */
> +/* u8 count_voice_channels; // count voice channels supported by current TDM controller */
Remove commented out code?
> + /* List of voice channels */
> + struct list_head voice_channels;
> +
> + /* TDM hardware settings */
> + struct tdm_controller_hw_settings *settings;
> +
> + int (*setup_voice_channel)(struct tdm_voice_channel *ch);
> + int (*send)(struct tdm_voice_channel *ch, u8 *data);
> + int (*recv)(struct tdm_voice_channel *ch, u8 *data);
> + int (*run_audio)(struct tdm_device *tdm_dev);
> + int (*stop_audio)(struct tdm_device *tdm_dev);
> + int (*poll_rx)(struct tdm_device *tdm_dev);
> + int (*poll_tx)(struct tdm_device *tdm_dev);
> +
> + /* called on release() for TDM device to free memory provided by tdm_controller */
> + void (*cleanup)(struct tdm_device *tdm);
> +};
> +
> +
> +
> +/*
> + * Board specific information for requested TDM channel
> + */
> +struct tdm_board_info {
> + /* the device name and module name are coupled, like platform_bus;
> + * "modalias" is normally the driver name.
> + *
> + * platform_data goes to tdm_controller.dev.platform_data,
> + * controller_data goes to tdm_device.controller_data,
> + * irq is copied too
> + */
> + char modalias[32];
> +
> + /* bus_num is board specific and matches the bus_num of some
> + * tdm_controller that will probably be registered later.
> + */
> + u16 bus_num;
> +
> + const void *platform_data;
> + void *controller_data;
> +
> + u8 tdm_channel_num; /* Number TDM channel for connected device */
> + u8 buffer_sample_count; /* Size for transmit and receive buffer */
> + u8 mode_wideband; /* 1 - Enable wideband mode for requested TDM */
> +
> + struct list_head list; /* Entry for union all board info */
> +};
> +
> +
> +
> +
> +/**
> + * Search address tdm_controller structure contained device stucture
> + * @param dev - device
> + * @return pointer to tdm_device
> + */
> +static inline struct tdm_controller *to_tdm_controller(struct device *dev) {
> + return dev ? container_of(dev, struct tdm_controller, dev) : NULL;
> +}
Do you really need the dev check? Why would a caller be doing
to_tdm_controller on a NULL device?
> +
> +
> +/**
> + * Search address tdm_device structure contained device stucture
> + * @param dev - device
> + * @return pointer to tdm_device
> + */
> +static inline struct tdm_device *to_tdm_device(struct device *dev) {
> + return dev ? container_of(dev, struct tdm_device, dev) : NULL;
> +}
> +
> +/**
> + * Search address tdm_driver structure contained device stucture
> + * @param dev - device
> + * @return pointer to tdm_driver
> + */
> +static inline struct tdm_driver *to_tdm_driver(struct device_driver *drv) {
> + return drv ? container_of(drv, struct tdm_driver, driver) : NULL;
> +}
> +
> +
> +/**
> + * Get private driver tdm controller data
> + * @param tdm
> + */
> +static inline void *tdm_controller_get_devdata(struct tdm_controller *tdm)
> +{
> + return dev_get_drvdata(&tdm->dev);
> +}
Nitpick - This helper function is actually more verbose than the
function it calls :-).
> +
> +
> +/**
> + * decrement pointer counter to tdm_controller
> + * @param tdm - tdm_controller
> + */
> +static inline void tdm_controller_put(struct tdm_controller *tdm)
> +{
> + if (tdm)
> + put_device(&tdm->dev);
> +}
This function really shouldn't have a check for dev, since presumably
you had to get the device in able to put it, so hopefully it isn't
NULL.
> +
> +
> +/**
> + * Increment pointer counter to tdm_controller
> + * @param tdm - tdm_controller
> + */
> +static inline struct tdm_controller *tdm_controller_get(struct tdm_controller *tdm) {
> + if (!tdm || !get_device(&tdm->dev))
> + return NULL;
> + return tdm;
> +}
> +
> +
> +/**
> + * Store private data for tdm device
> + * @param tdm_dev - tdm device
> + * @param data - private data
> + */
> +static inline void tdm_set_drvdata(struct tdm_device *tdm_dev, void *data)
> +{
> + dev_set_drvdata(&tdm_dev->dev, data);
> +}
> +
> +
> +/**
> + * Get stored early private data for tdm device
> + * @param tdm_dev - tdm device
> + */
> +static inline void *tdm_get_drvdata(struct tdm_device *tdm_dev)
> +{
> + return dev_get_drvdata(&tdm_dev->dev);
> +}
> +
> +
> +int tdm_register_driver(struct tdm_driver *tdm_drv);
> +
> +void tdm_unregister_driver(struct tdm_driver *tdm_dev);
> +
> +struct tdm_controller *tdm_alloc_controller(struct device *dev, unsigned size);
> +
> +struct tdm_voice_channel *tdm_alloc_voice_channel(void);
> +
> +int tdm_free_controller(struct tdm_controller *tdm);
> +
> +int tdm_controller_register(struct tdm_controller *tdm);
> +
> +void tdm_controller_unregister(struct tdm_controller *tdm);
> +
> +struct tdm_device *tdm_new_device(struct tdm_controller *tdm,
> + struct tdm_board_info *chip);
> +
> +int tdm_add_device(struct tdm_device *tdm_dev);
> +
> +int tdm_recv(struct tdm_device *tdm_dev, u8 *data);
> +
> +int tdm_send(struct tdm_device *tdm_dev, u8 *data);
> +
> +int tdm_run_audio(struct tdm_device *tdm_dev);
> +
> +int tdm_stop_audio(struct tdm_device *tdm_dev);
> +
> +int tdm_poll_rx(struct tdm_device *tdm_dev);
> +
> +int tdm_poll_tx(struct tdm_device *tdm_dev);
> +
> +int tdm_get_voice_block_size(struct tdm_device *tdm_dev);
> +
> +int
> +tdm_register_new_voice_channel(struct tdm_controller *tdm,
> + struct tdm_voice_channel *ch,
> + void *driver_private);
> +
> +int tdm_free_voice_channels(struct tdm_controller *tdm);
> +
> +struct tdm_voice_channel *
> +get_voice_channel_by_num(struct tdm_controller *tdm, int num);
> +
> +
> +#ifdef CONFIG_TDM
Why is this ifdef here, don't you need CONFIG_TDM for all of the
above also?
> +int __init
> +tdm_register_board_info(struct tdm_board_info const *info, unsigned n);
> +#else
> +/* board init code may ignore whether TDM is configured or not */
> +static inline int __init
> +tdm_register_board_info(struct tdm_board_info const *info, unsigned n)
> +{
> + return 0;
> +}
> +#endif
> +
> +#endif /* TDM_BASE_H_ */
> diff --git a/drivers/staging/tdm/tdm_core.c b/drivers/staging/tdm/tdm_core.c
> new file mode 100644
> index 0000000..0182a4f
> --- /dev/null
> +++ b/drivers/staging/tdm/tdm_core.c
> @@ -0,0 +1,826 @@
> +/**********************************************************************
> + * Author: Michail Kurachkin
> + *
> + * Contact: michail.kurachkin@...mwad.com
> + *
> + * Copyright (c) 2013 Promwad Inc.
> + *
> + * This file 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 file is distributed in the hope that it will be useful, but
> + * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
> + * NONINFRINGEMENT. See the GNU General Public License for more
> + * details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this file; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> + * or visit http://www.gnu.org/licenses/.
> +**********************************************************************/
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/sched.h>
> +#include <linux/interrupt.h>
> +#include <linux/types.h>
> +#include <linux/device.h>
> +#include <linux/spinlock.h>
> +#include <linux/platform_device.h>
> +#include "tdm.h"
> +
> +#include <linux/cache.h>
> +#include <linux/mutex.h>
> +#include <linux/mod_devicetable.h>
> +
> +static void tdmdev_release(struct device *dev)
> +{
> + struct tdm_device *tdm_dev = to_tdm_device(dev);
> +
> + /* tdm controllers may cleanup for released devices */
> + if (tdm_dev->controller->cleanup)
> + tdm_dev->controller->cleanup(tdm_dev);
> +
> + put_device(&tdm_dev->controller->dev);
> + kfree(tdm_dev);
> +}
> +
> +static ssize_t
> +modalias_show(struct device *dev, struct device_attribute *a, char *buf)
> +{
> + const struct tdm_device *tdm_dev = to_tdm_device(dev);
> +
> + return sprintf(buf, "%s\n", tdm_dev->modalias);
> +}
> +
> +static struct device_attribute tdm_dev_attrs[] = {
> + __ATTR_RO(modalias),
> + __ATTR_NULL,
> +};
> +
> +
> +static int tdm_match_device(struct device *dev, struct device_driver *drv)
> +{
> + const struct tdm_device *tdm_dev = to_tdm_device(dev);
> +
> + return strcmp(tdm_dev->modalias, drv->name) == 0;
> +}
> +
> +
> +static int tdm_uevent(struct device *dev, struct kobj_uevent_env *env)
> +{
> + const struct tdm_device *tdm_dev = to_tdm_device(dev);
> +
> + add_uevent_var(env, "MODALIAS=%s%s", "tdm:", tdm_dev->modalias);
> + return 0;
> +}
> +
> +
> +static void tdm_release(struct device *dev)
> +{
> + struct tdm_device *tdm_dev;
> +
> + tdm_dev = to_tdm_device(dev);
> +
> + kfree(tdm_dev);
> +}
> +
> +
> +static struct class tdm_class = {
> + .name = "tdm",
> + .owner = THIS_MODULE,
> + .dev_release = tdm_release,
> + };
Indentation is all messed here.
> +
> +
> +
> +/**
> + * Struct for TDM bus
> + */
> +struct bus_type tdm_bus_type = {
> + .name = "tdm",
> + .dev_attrs = tdm_dev_attrs,
> + .match = tdm_match_device,
> + .uevent = tdm_uevent,
> + .suspend = NULL,
> + .resume = NULL,
Nitpick - You can ommit the NULL fields, they will automatically
be initialised to NULL.
> +};
> +EXPORT_SYMBOL_GPL(tdm_bus_type);
> +
> +
> +
> +static int tdm_drv_probe(struct device *dev)
> +{
> + const struct tdm_driver *tdm_drv = to_tdm_driver(dev->driver);
> +
> + return tdm_drv->probe(to_tdm_device(dev));
> +}
> +
> +static int tdm_drv_remove(struct device *dev)
> +{
> + const struct tdm_driver *tdm_drv = to_tdm_driver(dev->driver);
> +
> + return tdm_drv->remove(to_tdm_device(dev));
> +}
> +
> +static void tdm_drv_shutdown(struct device *dev)
> +{
> + const struct tdm_driver *tdm_drv = to_tdm_driver(dev->driver);
> +
> + tdm_drv->shutdown(to_tdm_device(dev));
> +}
> +
> +
> +/**
> + * tdm_register_driver - register a TDM driver
> + * @sdrv: the driver to register
> + * Context: can sleep
> + */
> +int tdm_register_driver(struct tdm_driver *tdm_drv)
> +{
> + tdm_drv->driver.bus = &tdm_bus_type;
> +
> + if (tdm_drv->probe)
> + tdm_drv->driver.probe = tdm_drv_probe;
> +
> + if (tdm_drv->remove)
> + tdm_drv->driver.remove = tdm_drv_remove;
> +
> + if (tdm_drv->shutdown)
> + tdm_drv->driver.shutdown = tdm_drv_shutdown;
You don't need the checks here, since you will just end up
assigning NULL if the various callbacks are not set.
> + return driver_register(&tdm_drv->driver);
> +}
> +EXPORT_SYMBOL_GPL(tdm_register_driver);
> +
> +
> +/**
> + * tdm_unregister_driver - reverse effect of tdm_register_driver
> + * @sdrv: the driver to unregister
> + * Context: can sleep
> + */
> +void tdm_unregister_driver(struct tdm_driver *tdm_dev)
> +{
> + if (tdm_dev)
> + driver_unregister(&tdm_dev->driver);
> +}
> +EXPORT_SYMBOL_GPL(tdm_unregister_driver);
> +
> +
> +
> +/**
> + * Request unused voice channel
> + * @param tdm_dev - TDM device requested voice channel
> + * @return pointer to voice channel
> + */
> +struct tdm_voice_channel *request_voice_channel(struct tdm_device *tdm_dev) {
> + struct tdm_controller *tdm = tdm_dev->controller;
> + struct tdm_voice_channel *ch;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&tdm->lock, flags);
All usage of tdm->lock use irqsave/irqrestore, but I can't see an
interrupt handlers in this patch. irqsave/restore should be used
when you don't know if the callsite will be run from interrupt
context or not. Is that the case here? Otherwise you should be
using normal spin_lock, or spin_lock_irq if this callsite runs
in process context, but other uses of the lock run in irq
context.
> +
> + list_for_each_entry(ch, &tdm->voice_channels, list)
> + if (ch->dev == NULL) {
> + ch->dev = &tdm_dev->dev;
> + tdm_dev->ch = ch;
> + spin_unlock_irqrestore(&tdm->lock, flags);
> + return ch;
> + }
> +
> + spin_unlock_irqrestore(&tdm->lock, flags);
> + return NULL;
> +}
> +
> +/**
> + * Release requested voice channel
> + * @param TDM device requested early voice channel
> + * @return 0 - OK
> + */
> +int release_voice_channel(struct tdm_device *tdm_dev)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> + struct tdm_voice_channel *ch;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&tdm->lock, flags);
> +
> + tdm_dev->ch = NULL;
> + list_for_each_entry(ch, &tdm->voice_channels, list)
> + if (ch->dev == &tdm_dev->dev) {
> + ch->dev = NULL;
> + spin_unlock_irqrestore(&tdm->lock, flags);
> + return 0;
> + }
> +
> + spin_unlock_irqrestore(&tdm->lock, flags);
> +
> + return -ENODEV;
> +}
> +
> +
> +
> +/*
> + * Container for union board info of all TDM devices
> + */
> +struct tdm_board_devices {
> + struct list_head list;
> + struct tdm_board_info bi; /* Board specific info */
> +};
> +
> +/* List of all board specific TDM devices */
> +static LIST_HEAD(tdm_devices_list);
> +
> +/* List of all registred TDM controllers */
> +static LIST_HEAD(tdm_controller_list);
> +
> +
> +/*
> + * Used to protect add/del opertion for board_info list and
> + * tdm_controller list, and their matching process
> + */
> +static DEFINE_MUTEX(board_lock);
> +
> +
> +static void tdm_match_controller_to_boardinfo(struct tdm_controller *tdm,
> + struct tdm_board_info *bi)
> +{
> + struct tdm_device *tdm_dev;
> +
> + if (tdm->bus_num != bi->bus_num)
> + return;
> +
> + tdm_dev = tdm_new_device(tdm, bi);
> + if (!tdm_dev)
> + dev_err(tdm->dev.parent, "can't create new device for %s\n",
> + bi->modalias);
> +}
This function is confusingly named. It's name suggested it should return
true if the boardinfo matches the device, but instead it goes and
allocates a new device on match. It also doesn't propogate any errors
back to the caller if the device allocation fails.
> +
> +
> +
> +/**
> + * Allocate memory for TDM controller device
> + * @dev: the controller, possibly using the platform_bus
> + * @size: how much zeroed driver-private data to allocate; the pointer to this
> + * memory is in the driver_data field of the returned device,
> + * accessible with tdm_controller_get_devdata().
> + * Context: can sleep
> + */
> +struct tdm_controller *tdm_alloc_controller(struct device *dev, unsigned size) {
> + struct tdm_controller *tdm;
> +
> + if (!dev)
> + return NULL;
> +
> + tdm = kzalloc(sizeof *tdm + size, GFP_KERNEL);
Nitpick:
sizeof(*tdm)
is more typical.
> + if (!tdm)
> + return NULL;
> +
> + device_initialize(&tdm->dev);
> + tdm->dev.class = &tdm_class;
> + tdm->dev.parent = get_device(dev);
> + spin_lock_init(&tdm->lock);
> + INIT_LIST_HEAD(&tdm->list);
> + INIT_LIST_HEAD(&tdm->voice_channels);
> +
> + dev_set_drvdata(&tdm->dev, tdm + 1);
> +
> + return tdm;
> +}
> +EXPORT_SYMBOL_GPL(tdm_alloc_controller);
> +
> +
> +/**
> + * Free memory for TDM controller device, allocated by tdm_alloc_controller
> + * @dev: the controller, possibly using the platform_bus
> + * Context: can sleep
> + */
> +int tdm_free_controller(struct tdm_controller *tdm)
> +{
> + if (!tdm)
> + return -EINVAL;
> +
> + dev_set_drvdata(&tdm->dev, NULL);
> + put_device(&tdm->dev);
> + kzfree(tdm);
Is kzfree, rather than just plain kfree, really necessary?
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(tdm_free_controller);
> +
> +
> +/**
> + * Allocate memory for voice channel
> + * @return object voice_channel or NULL if error
> + */
> +struct tdm_voice_channel *tdm_alloc_voice_channel(void)
> +{
> + struct tdm_voice_channel *ch;
> +
> + ch = kzalloc(sizeof *ch, GFP_KERNEL);
> + if (!ch)
> + return NULL;
> +
> + memset(ch, 0, sizeof *ch);
Remove the memset. kzalloc already clears the memory.
> + init_waitqueue_head(&ch->tx_queue);
> + init_waitqueue_head(&ch->rx_queue);
> +
> + return ch;
> +}
> +EXPORT_SYMBOL_GPL(tdm_alloc_voice_channel);
> +
> +
> +
> +/**
> + * Add allocated voice channel in tdm controller
> + * @param tdm - tdm controller
> + * @param ch - allocated voice channel
> + * @param driver_private - private driver structure
> + * @return 0 - ok
> + */
> +int
> +tdm_register_new_voice_channel(struct tdm_controller *tdm,
> + struct tdm_voice_channel *ch,
> + void *driver_private)
> +{
> + struct tdm_voice_channel *c;
> + int last_num;
> +
> + last_num = -1;
> + list_for_each_entry(c, &tdm->voice_channels, list)
> + if (c->channel_num > last_num)
> + last_num = c->channel_num;
Should this list access be protected by tdm->lock? If the caller
needs to hold the lock then that should be documented.
> +
> + ch->channel_num = last_num + 1;
> + ch->private_data = driver_private;
> + list_add_tail(&ch->list, &tdm->voice_channels);
Same here, this probably needs to be protected by tdm->lock.
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(tdm_register_new_voice_channel);
> +
> +/**
> + * free memory for voice channels allocated by tdm_alloc_voice_channels
> + * @param tdm - TDM controller
> + * @param count_channels - count supported voice channels
> + * @return
> + */
> +int tdm_free_voice_channels(struct tdm_controller *tdm)
> +{
> + struct tdm_voice_channel *ch, *ch_tmp;
> + if (!tdm)
> + return -EINVAL;
> +
> + list_for_each_entry_safe(ch, ch_tmp, &tdm->voice_channels, list)
> + {
> + list_del(&ch->list);
> + kzfree(ch);
> + }
Locking? If it is the callers responsibility, document it.
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(tdm_free_voice_channels);
> +
> +
> +/**
> + * get voice_channel object by voice number
> + * @param tdm - tdm_controller contained voice channels
> + * @param num - voice channel number
> + * @return voice_channel object or NULL
> + */
> +struct tdm_voice_channel *
> +get_voice_channel_by_num(struct tdm_controller *tdm, int num)
> +{
> + struct tdm_voice_channel *ch;
> + list_for_each_entry(ch, &tdm->voice_channels, list)
> + if (ch->channel_num == num)
> + return ch;
Locking.
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(get_voice_channel_by_num);
> +
> +
> +/**
> + * tdm_controller_register - register TDM controller
> + * @master: initialized master, originally from spi_alloc_master()
> + * Context: can sleep
> + *
> + * This must be called from context that can sleep. It returns zero on
> + * success, else a negative error code (dropping the master's refcount).
> + * After a successful return, the caller is responsible for calling
> + * tdm_controller_unregister().
> + */
> +int tdm_controller_register(struct tdm_controller *tdm)
> +{
> + static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
> + struct device *dev = tdm->dev.parent;
> + struct tdm_board_devices *bi;
> + int status = -ENODEV;
> + int dynamic = 0;
> +
> + if (!dev) {
> + dev_err(dev, "parent device not exist\n");
> + return -ENODEV;
> + }
> +
> + /* convention: dynamically assigned bus IDs count down from the max */
> + if (tdm->bus_num < 0) {
> + tdm->bus_num = atomic_dec_return(&dyn_bus_id);
I haven't looked at the other patches yet, but this is the only place
that dyn_bys_id is used in this patch. Does it really need to be
atomic, or can it just be a plain int protected by a mutex? Atomics
can be somewhat difficult to get correct since atomic != concurrency
safe.
> + dynamic = 1;
> + }
> +
> + /* register the device, then userspace will see it.
> + * registration fails if the bus ID is in use.
> + */
> + dev_set_name(&tdm->dev, "tdm%u", tdm->bus_num);
> + status = device_add(&tdm->dev);
> + if (status < 0) {
> + dev_err(dev, "cannot added controller device, %d\n", status);
> + goto done;
> + }
> + dev_dbg(dev, "registered controller %s%s\n", dev_name(&tdm->dev),
> + dynamic ? " (dynamic)" : "");
> +
> + mutex_lock(&board_lock);
> + list_add_tail(&tdm->list, &tdm_controller_list);
> + list_for_each_entry(bi, &tdm_devices_list, list)
> + tdm_match_controller_to_boardinfo(tdm, &bi->bi);
> +
> + mutex_unlock(&board_lock);
> +
> + status = 0;
Nitpick - If you initialise status to 0 above then you can remove
this line.
> +done:
> + return status;
> +}
> +EXPORT_SYMBOL_GPL(tdm_controller_register);
> +
> +
> +static int __unregister(struct device *dev, void *null)
> +{
> + device_unregister(dev);
> + return 0;
> +}
> +
> +
> +/**
> + * tdm_controller_unregister - unregister TDM controller
> + * @tdm: the controller being unregistered
> + * Context: can sleep
> + *
> + * This call is used only by TDM controller drivers, which are the
> + * only ones directly touching chip registers.
> + *
> + * This must be called from context that can sleep.
> + */
> +void tdm_controller_unregister(struct tdm_controller *tdm)
> +{
> + int dummy;
> +
> + mutex_lock(&board_lock);
> + list_del(&tdm->list);
> + mutex_unlock(&board_lock);
> +
> + dummy = device_for_each_child(&tdm->dev, NULL, __unregister);
device_for_each_child is not __must_check, so you can remove the
dummy variable.
> + device_unregister(&tdm->dev);
> +}
> +EXPORT_SYMBOL_GPL(tdm_controller_unregister);
> +
> +
> +/**
> + * tdm_new_device - instantiate one new TDM device
> + * @tdm: TDM Controller to which device is connected
> + * @chip: Describes the TDM device
> + * Context: can sleep
> + *
> + * Returns the new device, or NULL.
> + */
> +struct tdm_device *tdm_new_device(struct tdm_controller *tdm,
> + struct tdm_board_info *chip) {
> + struct tdm_device *tdm_dev;
> + int status;
> +
> + if (!tdm_controller_get(tdm))
> + return NULL;
> +
> + tdm_dev = kzalloc(sizeof *tdm_dev, GFP_KERNEL);
> + if (!tdm_dev) {
> + dev_err(tdm->dev.parent, "cannot alloc for TDM device\n");
You don't need to print errors on kalloc failures, you will
automatically get a stack trace.
> + tdm_controller_put(tdm);
> + return NULL;
> + }
> +
> + tdm_dev->controller = tdm;
> + tdm_dev->dev.parent = tdm->dev.parent;
> + tdm_dev->dev.bus = &tdm_bus_type;
> + tdm_dev->dev.release = tdmdev_release;
> + device_initialize(&tdm_dev->dev);
> +
> + WARN_ON(strlen(chip->modalias) >= sizeof(tdm_dev->modalias));
> +
> + tdm_dev->tdm_channel_num = chip->tdm_channel_num;
> + tdm_dev->mode_wideband = chip->mode_wideband;
> + tdm_dev->buffer_sample_count = chip->buffer_sample_count;
> + strlcpy(tdm_dev->modalias, chip->modalias, sizeof(tdm_dev->modalias));
> +
> + status = tdm_add_device(tdm_dev);
> + if (status < 0) {
> + put_device(&tdm_dev->dev);
> + return NULL;
> + }
> +
> + return tdm_dev;
> +}
> +EXPORT_SYMBOL_GPL(tdm_new_device);
> +
> +
> +
> +/**
> + * tdm_add_device - Add tdm_device on TDM bus
> + * @tdm_dev: TDM device to register
> + *
> + * Returns 0 on success; negative errno on failure
> + */
> +int tdm_add_device(struct tdm_device *tdm_dev)
> +{
> + static DEFINE_MUTEX(tdm_add_lock);
Ick, please move this out of the function.
> + struct tdm_controller *tdm = tdm_dev->controller;
> + struct tdm_controller_hw_settings *hw = tdm->settings;
> + struct device *dev = tdm->dev.parent;
> + struct device *d;
> + struct tdm_voice_channel *ch;
> + int status;
> + u8 count_tdm_channels;
> +
> +
> + if (tdm_dev->mode_wideband) {
> + dev_err(dev, "mode_wideband is not supported by this driver\n");
> + status = -EINVAL;
> + goto done;
> + }
> +
> + count_tdm_channels = hw->count_time_slots / hw->channel_size;
> +
> + if (tdm_dev->tdm_channel_num >= count_tdm_channels) {
> + dev_err(dev, "Incorrect requested TDM channel.\n"
> + "Requested %d TDM channel, %d TDM channels available.\n",
> + tdm_dev->tdm_channel_num, count_tdm_channels);
> +
> + status = -EINVAL;
> + goto done;
> + }
> +
> + if (tdm_dev->mode_wideband &&
You just rejected mode_wideband devices above?
> + (tdm_dev->tdm_channel_num > count_tdm_channels / 2)) {
> + dev_err(dev, "Incorrect requested TDM channel in wideband mode.\n"
> + "Requested %d TDM channel, %d TDM channels available\n"
> + "in wideband mode\n",
> + tdm_dev->tdm_channel_num, count_tdm_channels / 2);
> +
> + status = -EINVAL;
> + goto done;
> + }
> +
> +
> + /* Set the bus ID string */
> + dev_set_name(&tdm_dev->dev, "%s.%u", dev_name(&tdm_dev->controller->dev),
> + tdm_dev->tdm_channel_num);
> +
> + /* We need to make sure there's no other device with this
> + * chipselect **BEFORE** we call setup(), else we'll trash
> + * its configuration. Lock against concurrent add() calls.
> + */
> + mutex_lock(&tdm_add_lock);
> +
> + d = bus_find_device_by_name(&tdm_bus_type, NULL, dev_name(&tdm_dev->dev));
> + if (d != NULL) {
> + dev_err(dev, "TDM channel %d already in use\n",
> + tdm_dev->tdm_channel_num);
> + put_device(d);
> + status = -EBUSY;
> + goto done;
> + }
> +
> + ch = request_voice_channel(tdm_dev);
> + if (ch == NULL) {
> + dev_err(dev, "Can't request TDM voice channel. All voice channels is busy\n");
> + status = -EBUSY;
> + goto done;
Missing put_device.
> + }
> +
> + printk("ch = %s\n", dev_name(ch->dev));
Left over debugging? Remove or change to dev_dbg.
> + /* Configuring voice channel */
> + ch->mode_wideband = tdm_dev->mode_wideband;
> + ch->tdm_channel = tdm_dev->tdm_channel_num;
> +
> + /* Run setup voice channel */
> + status = tdm_dev->controller->setup_voice_channel(ch);
> + if (status < 0) {
> + dev_err(dev, "can't setup voice channel, status %d\n", status);
> + goto done;
Missing put_device.
> + }
> +
> + /* Device may be bound to an active driver when this returns */
> + status = device_add(&tdm_dev->dev);
> + if (status < 0)
> + dev_err(dev, "can't add %s, status %d\n",
> + dev_name(&tdm_dev->dev), status);
> + else
> + dev_dbg(dev, "registered child %s\n", dev_name(&tdm_dev->dev));
> +
> +done:
> + mutex_unlock(&tdm_add_lock);
> + return status;
> +}
> +EXPORT_SYMBOL_GPL(tdm_add_device);
> +
> +
> +
> +/**
> + * Receive audio-data from tdm device.
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @param data - pointer to receive block data.
> + * Allocated data size must be equal value
> + * returned by tdm_get_voice_block_size();
Is it possible to check this inside the function and return
-EINVAL if it is not true, so that dodgy callers can't cause
an overflow?
> + * @return 0 - success
> + */
> +int tdm_recv(struct tdm_device *tdm_dev, u8 *data)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> +
> + if (tdm_dev->ch == NULL)
> + return -ENODEV;
> +
> + return tdm->recv(tdm_dev->ch, data);
> +}
> +EXPORT_SYMBOL_GPL(tdm_recv);
> +
> +
> +/**
> + * Transmit audio-data from tdm device.
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @param data - pointer to transmit block data.
> + * Transmit data size must be equal value
> + * returned by tdm_get_voice_block_size();
> + * @return 0 - success
> + */
> +int tdm_send(struct tdm_device *tdm_dev, u8 *data)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> +
> + if (tdm_dev->ch == NULL)
> + return -ENODEV;
> +
> + return tdm->send(tdm_dev->ch, data);
> +}
> +EXPORT_SYMBOL_GPL(tdm_send);
> +
> +
> +/**
> + * Enable audio transport
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @return 0 - success
> + */
> +int tdm_run_audio(struct tdm_device *tdm_dev)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> +
> + if (!tdm_dev->ch) {
> + dev_err(&tdm_dev->dev, "Can't run audio because not allocated tdm voice channel\n");
> + return -ENODEV;
> + }
> +
> + return tdm->run_audio(tdm_dev);
> +}
> +EXPORT_SYMBOL_GPL(tdm_run_audio);
> +
> +
> +/**
> + * Disable audio transport
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @return 0 - success
> + */
> +int tdm_stop_audio(struct tdm_device *tdm_dev)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> +
> + if (!tdm_dev->ch) {
> + dev_err(&tdm_dev->dev, "Can't stop audio because not allocated tdm voice channel\n");
> + return -ENODEV;
> + }
> +
> + return tdm->stop_audio(tdm_dev);
> +}
> +EXPORT_SYMBOL_GPL(tdm_stop_audio);
> +
> +
> +
> +/**
> + * Check rx audio buffer for exist new data
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @return 0 - not enought data, 1 - data exist
> + */
> +int tdm_poll_rx(struct tdm_device *tdm_dev)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> +
> + return tdm->poll_rx(tdm_dev);
> +}
> +EXPORT_SYMBOL_GPL(tdm_poll_rx);
> +
> +
> +/**
> + * Check tx audio buffer for free space
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @return 0 - not enought free space, 1 - exist free space
> + */
> +int tdm_poll_tx(struct tdm_device *tdm_dev)
> +{
> + struct tdm_controller *tdm = tdm_dev->controller;
> +
> + return tdm->poll_tx(tdm_dev);
> +}
> +EXPORT_SYMBOL_GPL(tdm_poll_tx);
> +
> +
> +/**
> + * Get voice block size for transmit or receive operations
> + * @param tdm_dev - tdm device registered on TDM bus
> + * @return voice block size, or error if returned value less 0
> + */
> +int tdm_get_voice_block_size(struct tdm_device *tdm_dev)
> +{
> + struct tdm_voice_channel *ch;
> +
> + ch = tdm_dev->ch;
> + if (ch == NULL)
> + return -ENODEV;
> +
> + return ch->buffer_len;
> +}
> +EXPORT_SYMBOL_GPL(tdm_get_voice_block_size);
> +
> +
> +
> +/**
> + * tdm_register_board_info - register TDM devices for a given board
> + * @info: array of chip descriptors
> + * @n: how many descriptors are provided
> + * Context: can sleep
> + */
> +int __init
> +tdm_register_board_info(struct tdm_board_info const *info, unsigned n)
> +{
> + struct tdm_board_devices *bi;
> + int i;
> +
> + bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
Use kcalloc.
> + if (!bi)
> + return -ENOMEM;
> +
> + for (i = 0; i < n; i++, bi++, info++) {
> + struct tdm_controller *tdm;
> +
> + memcpy(&bi->bi, info, sizeof(*info));
> + mutex_lock(&board_lock);
> +
> + list_add_tail(&bi->list, &tdm_devices_list);
> + list_for_each_entry(tdm, &tdm_controller_list, list)
> + tdm_match_controller_to_boardinfo(tdm, &bi->bi);
> +
> + mutex_unlock(&board_lock);
> + }
> +
> + return 0;
> +}
> +
> +
> +
> +static int __init tdm_core_init(void)
> +{
> + int status;
> +
> + status = bus_register(&tdm_bus_type);
> + if (status < 0)
> + goto err0;
> +
> + status = class_register(&tdm_class);
> + if (status < 0)
> + goto err1;
> + return 0;
> +
> +err1:
> + bus_unregister(&tdm_bus_type);
> +err0:
> + return status;
> +}
> +
> +postcore_initcall(tdm_core_init);
> +
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