Date:	Tue, 13 Jul 2010 00:55:44 -0700
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	Trilok Soni <tsoni@...eaurora.org>
Cc:	Kevin McNeely <kev@...ress.com>,
	David Brown <davidb@...eaurora.org>,
	Fred <fwk@...ntu.linuxcertified.com>,
	Samuel Ortiz <sameo@...ux.intel.com>,
	Eric Miao <eric.y.miao@...il.com>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Simtec Linux Team <linux@...tec.co.uk>,
	Arnaud Patard <arnaud.patard@...-net.org>,
	Antonio Ospite <ospite@...denti.unina.it>,
	Henrik Rydberg <rydberg@...omail.se>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-i2c@...r.kernel.org, khali@...ux-fr.org,
	linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH] i2c: cyttsp i2c touchscreen driver init submit

On Tue, Jul 13, 2010 at 01:01:32PM +0530, Trilok Soni wrote:
> Hi Kevin,
> 
> Thanks for posting this driver.
> 
> Adding Jean Delvar for i2c bits.
> 
> On 7/13/2010 2:26 AM, Kevin McNeely wrote:
> > From: Fred <fwk@...ntu.linuxcertified.com>
> 
> E-mail id looks wrong. Do you mean fwk@...ress.com?
> 
> > 
> > This is a new touchscreen driver for the Cypress Semiconductor
> > cyttsp family of devices.  This driver is for the i2c version
> > of cyttsp parts.
> 
> Please explain in commit text which exact version of the chips this driver is supporting.
> It is hard to make out that from this text.
> > 
> > Signed-off-by: Kevin McNeely <kev@...ress.com>
> > ---
> >  drivers/input/touchscreen/Kconfig      |   13 +
> >  drivers/input/touchscreen/Makefile     |    1 +
> >  drivers/input/touchscreen/cyttsp-i2c.c | 2016 ++++++++++++++++++++++++++++++++
> >  include/linux/cyttsp.h                 |  649 ++++++++++
> 
> Please move this file to include/linux/input directory.
> 

Or even keep it in drivers/input/touchscreen/

> 
> > 
> > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> > index 3b9d5e2..a7a69a0 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -603,4 +603,17 @@ config TOUCHSCREEN_TPS6507X
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called tps6507x_ts.
> >  
> > +config TOUCHSCREEN_CYTTSP_I2C
> > +	default n
> 
> Do we need to provide this if it is no by default?
> 
> > +	tristate "Cypress TTSP i2c touchscreen"
> > +	depends on I2C
> > +	help
> > +	  Say Y here if you have a Cypress TTSP touchscreen
> > +	  connected to your system's i2c bus.
> 
> What is TTSP?
> 
> > +
> > +	  If unsure, say N.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called cyttsp_i2c.
> > +
> >  endif
> 

Since there is SPI part should we prepare for the support and split
bus-independent parts off? Are you working on SPI support?

> 
> > diff --git a/drivers/input/touchscreen/cyttsp-i2c.c b/drivers/input/touchscreen/cyttsp-i2c.c
> > new file mode 100644
> > index 0000000..8397aa1
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/cyttsp-i2c.c
> > @@ -0,0 +1,2016 @@
> > +/* Source for:
> > + * Cypress TrueTouch(TM) Standard Product I2C touchscreen driver.
> > + * drivers/input/touchscreen/cyttsp-i2c.c
> 
> No file paths please. Already commented on it by Christoph.
> 
> > + *
> > + * Copyright (C) 2009, 2010 Cypress Semiconductor, Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License
> > + * version 2, and only 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.
> > + *
> > + * You should have received a copy of the GNU General Public License along
> > + * with this program; if not, write to the Free Software Foundation, Inc.,
> > + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> > + *
> > + * Cypress reserves the right to make changes without further notice
> > + * to the materials described herein. Cypress does not assume any
> > + * liability arising out of the application described herein.
> > + *
> > + * Contact Cypress Semiconductor at www.cypress.com
> 
> I would like Dmitry to comment on it. Dmitry?
> 

Not a lwayer but I do not really see an issue here. It is still GPL and
they as copyright holders obviously can modify the code. What exactly
troubles you here?


> > + *
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/i2c.h>
> > +#include <linux/input.h>
> > +#include <linux/slab.h>
> > +#include <linux/gpio.h>
> > +#include <linux/irq.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/timer.h>
> > +#include <linux/workqueue.h>
> > +#include <linux/byteorder/generic.h>
> > +#include <linux/bitops.h>
> > +#ifdef CONFIG_HAS_EARLYSUSPEND
> > +#include <linux/earlysuspend.h>
> > +#endif /* CONFIG_HAS_EARLYSUSPEND */
> 
> We don't have early suspend support yet into the mainline kernel. Please remove this code from the driver.
> 
> > +
> > +#define CY_DECLARE_GLOBALS
> 
> Could you please explain what it does?
> 
> > +
> > +#include <linux/cyttsp.h>
> > +
> > +uint32_t cyttsp_tsdebug1 = 0xff;
> > +module_param_named(tsdebug1, cyttsp_tsdebug1, uint, 0664);
> > +
> > +/* CY TTSP I2C Driver private data */
> > +struct cyttsp {
> > +	struct i2c_client *client;
> > +	struct input_dev *input;
> > +	struct work_struct work;
> > +	struct timer_list timer;
> > +	struct mutex mutex;
> > +	char phys[32];
> > +	struct cyttsp_platform_data *platform_data;
> > +	u8 num_prv_st_tch;
> > +	u16 act_trk[CY_NUM_TRK_ID];
> > +	u16 prv_st_tch[CY_NUM_ST_TCH_ID];
> > +	u16 prv_mt_tch[CY_NUM_MT_TCH_ID];
> > +	u16 prv_mt_pos[CY_NUM_TRK_ID][2];
> > +	atomic_t irq_enabled;
> > +#ifdef CONFIG_HAS_EARLYSUSPEND
> > +	struct early_suspend early_suspend;
> > +#endif /* CONFIG_HAS_EARLYSUSPEND */
> > +};
> > +static u8 irq_cnt;		/* comparison counter with register valuw */
> 
> s/valuw/value 
> 
> > +static u32 irq_cnt_total;	/* total interrupts */
> > +static u32 irq_err_cnt;		/* count number of touch interrupts with err */
> > +#define CY_IRQ_CNT_MASK	0x000000FF	/* mapped for sizeof count in reg */
> > +#define CY_IRQ_CNT_REG	0x00		/* tt_undef[0]=reg 0x1B - Gen3 only */
> > +
> > +#ifdef CONFIG_HAS_EARLYSUSPEND
> > +static void cyttsp_early_suspend(struct early_suspend *handler);
> > +static void cyttsp_late_resume(struct early_suspend *handler);
> > +#endif /* CONFIG_HAS_EARLYSUSPEND */
> > +
> > +static struct workqueue_struct *cyttsp_ts_wq;
> 
> Why there are so many global variables lying around?
> 
> > +
> > +
> > +/* ****************************************************************************
> > + * Prototypes for static functions
> > + * ************************************************************************** */
> > +static void cyttsp_xy_worker(struct work_struct *work);
> > +static irqreturn_t cyttsp_irq(int irq, void *handle);
> > +static int cyttsp_inlist(u16 prev_track[],
> > +			u8 cur_trk_id, u8 *prev_loc, u8 num_touches);
> > +static int cyttsp_next_avail_inlist(u16 cur_trk[],
> > +			u8 *new_loc, u8 num_touches);
> > +static int cyttsp_putbl(struct cyttsp *ts, int show,
> > +			int show_status, int show_version, int show_cid);
> > +static int __devinit cyttsp_probe(struct i2c_client *client,
> > +			const struct i2c_device_id *id);
> > +static int __devexit cyttsp_remove(struct i2c_client *client);
> > +static int cyttsp_resume(struct i2c_client *client);
> > +static int cyttsp_suspend(struct i2c_client *client, pm_message_t message);
> 
> Please re-order the functions in the driver such a way so that you don't need have these prototypes here.
> 
> > +
> > +/* Static variables */
> > +static struct cyttsp_gen3_xydata_t g_xy_data;
> > +static struct cyttsp_bootloader_data_t g_bl_data;
> > +static struct cyttsp_sysinfo_data_t g_sysinfo_data;
> 
> again globals?
> 
> > +static const struct i2c_device_id cyttsp_id[] = {
> > +	{ CY_I2C_NAME, 0 },  { }
> 
> Why dont you put ,{} at the next line.
> 
> > +};
> 
> You should not put driver name above, but it should be something like real chip name.
> 
> Say cy8ctXXX.
> 
> > +static u8 bl_cmd[] = {
> > +	CY_BL_FILE0, CY_BL_CMD, CY_BL_EXIT,
> > +	CY_BL_KEY0, CY_BL_KEY1, CY_BL_KEY2,
> > +	CY_BL_KEY3, CY_BL_KEY4, CY_BL_KEY5,
> > +	CY_BL_KEY6, CY_BL_KEY7};
> 
> and what these keys does?
> 
> > +
> > +MODULE_DEVICE_TABLE(i2c, cyttsp_id);
> 
> Why it is not with cyttsp_id above?
> 
> > +
> > +static struct i2c_driver cyttsp_driver = {
> > +	.driver = {
> > +		.name = CY_I2C_NAME,
> > +		.owner = THIS_MODULE,
> > +	},
> > +	.probe = cyttsp_probe,
> > +	.remove = __devexit_p(cyttsp_remove),
> > +	.suspend = cyttsp_suspend,
> > +	.resume = cyttsp_resume,
> > +	.id_table = cyttsp_id,
> > +};
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver");
> > +MODULE_AUTHOR("Cypress");
> 
> MODULE_ALIAS?
> 
> > +
> > +static ssize_t cyttsp_irq_status(struct device *dev,
> > +				struct device_attribute *attr, char *buf)
> > +{
> > +	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
> > +	struct cyttsp *ts = i2c_get_clientdata(client);
> > +	return sprintf(buf, "%u\n", atomic_read(&ts->irq_enabled));
> > +}
> > +
> > +static ssize_t cyttsp_irq_enable(struct device *dev,
> > +				struct device_attribute *attr,
> > +				const char *buf, size_t size)
> > +{
> > +	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
> > +	struct cyttsp *ts = i2c_get_clientdata(client);
> > +	int err = 0;
> > +	unsigned long value;
> > +
> > +	if (size > 2)
> > +		return -EINVAL;
> > +
> > +	err = strict_strtoul(buf, 10, &value);
> > +	if (err != 0)
> > +		return err;
> > +
> > +	switch (value) {
> > +	case 0:
> > +		if (atomic_cmpxchg(&ts->irq_enabled, 1, 0)) {
> > +			pr_info("touch irq disabled!\n");
> > +			disable_irq_nosync(ts->client->irq);

I do not believe that this achieves what you want.., You may reschedule
between cmpxchg and disable_irq_nosync().


Haven't looked any further yet...

-- 
Dmitry
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