Re: [PATCH] i2c: cyttsp i2c touchscreen driver init submit

Dmitry Torokhov
2010-07-13T07:55:55Z

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@ubuntu.linuxcertified.com>
>
> E-mail id looks wrong. Do you mean fwk@cypress.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@cypress.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