Re: [PATCH] input: touchscreen: add driver for Pixcir Tango C series capacitive touchscreen

[Barry Song <21cnbao@gmail.com>]

Hi Dmitry,
thanks for quick reviewing.

2013/9/20 Dmitry Torokhov <dmitry.torokhov@gmail.com>:
> Hi Barry,
>
> On Thu, Sep 19, 2013 at 04:38:31PM +0800, Barry Song wrote:
>> From: Lisai Wang <Lisai.Wang@csr.com>
>>
>> Pixcir Tango C series touchscreen support true multi-touch for 5 fingers. this
>> patch adds a driver for it.
>>
>> Signed-off-by: Lisai Wang <Lisai.Wang@csr.com>
>> Signed-off-by: Qipan Li <Qipan.Li@csr.com>

i made a mistake here, this should be Guoying.Zhang <Guoying.Zhang@csr.com>

>> Signed-off-by: Barry Song <Baohua.Song@csr.com>
>> ---
>>  drivers/input/touchscreen/Kconfig            |   10 +
>>  drivers/input/touchscreen/Makefile           |    1 +
>>  drivers/input/touchscreen/pixcir_tangoc_ts.c |  242 ++++++++++++++++++++++++++
>>  3 files changed, 253 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/input/touchscreen/pixcir_tangoc_ts.c
>>
>> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
>> index e09ec67..2b80df6 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -919,4 +919,14 @@ config TOUCHSCREEN_TPS6507X
>>         To compile this driver as a module, choose M here: the
>>         module will be called tps6507x_ts.
>>
>> +config TOUCHSCREEN_TANGOC
>> +     tristate "PIXCIR TANGOC touchscreen"
>> +     depends on I2C
>> +     help
>> +       Say Y here if you support PIXCIR TangoC touchscreen
>> +       controller
>> +
>> +       If unsure, Say N.
>> +       To compile this driver as a module, choose M here.
>> +
>>  endif
>> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
>> index f5216c1..ef73c06 100644
>> --- a/drivers/input/touchscreen/Makefile
>> +++ b/drivers/input/touchscreen/Makefile
>> @@ -75,3 +75,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)  += mainstone-wm97xx.o
>>  obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)    += zylonite-wm97xx.o
>>  obj-$(CONFIG_TOUCHSCREEN_W90X900)    += w90p910_ts.o
>>  obj-$(CONFIG_TOUCHSCREEN_TPS6507X)   += tps6507x-ts.o
>> +obj-$(CONFIG_TOUCHSCREEN_TANGOC)     += pixcir_tangoc_ts.o
>> diff --git a/drivers/input/touchscreen/pixcir_tangoc_ts.c b/drivers/input/touchscreen/pixcir_tangoc_ts.c
>> new file mode 100644
>> index 0000000..8274917
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/pixcir_tangoc_ts.c
>> @@ -0,0 +1,242 @@
>> +/*
>> +* Pixcir Tango C series 5 points touch controller Driver
>> +*
>> +* Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company.
>> +*
>> +* Licensed under GPLv2 or later.
>> +*/
>> +
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/i2c.h>
>> +#include <linux/gpio.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/input.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/slab.h>
>> +
>> +#define TOUCHSCREEN_MINX 0
>> +#define TOUCHSCREEN_MAXX 1024
>> +#define TOUCHSCREEN_MINY 0
>> +#define TOUCHSCREEN_MAXY 600
>> +#define TOUCH_MAJOR_MAX 50
>> +#define WIDTH_MAJOR_MAX 15
>> +#define TRACKING_ID_MAX 5
>> +
>> +struct pixcir_ts_point_data {
>> +     u16 posx;  /* x coordinate */
>> +     u16 posy;  /* y coordinate */
>
> Since this represents on-wire data you need to specify endianess (__le16?) and
> then explicitly convert it to CPU endianess when you use the data.

agree, this was tested on le ARM. so the original codes ignored be ARCH.

>
>> +     u8 id;    /* finger ID */
>> +} __packed;
>> +
>> +struct pixcir_ts_touch_data {
>> +     u16 touch_fingers;
>
> This should be __le16 or __be16 as well.
>
>> +     struct pixcir_ts_point_data point[5];
>> +} __packed;
>> +
>> +struct pixcir_ts_data {
>> +     struct i2c_client *client;
>> +     struct input_dev *input_dev;
>> +     unsigned int touch_pin;
>> +     struct pixcir_ts_touch_data touch_data;
>> +};
>> +
>> +/*Report the touch position*/
>> +static void  pixcir_ts_report_event(struct pixcir_ts_data *ts)
>> +{
>> +     int ret, i;
>> +     int fingers;
>> +     u8 addr;
>> +
>> +     addr = 0;
>> +     ret = i2c_master_send(ts->client, &addr, sizeof(addr));
>> +     if (ret != sizeof(addr)) {
>> +             dev_err(&ts->client->dev,
>> +                             "pixcir_ts:Unable to reset pixcir_ts!\n");
>
> Reset?

typo.

>
>> +             return;
>> +     }
>> +
>> +     ret = i2c_master_recv(ts->client, (char *)&ts->touch_data,
>> +                                     sizeof(struct pixcir_ts_touch_data));
>> +     if (ret != sizeof(struct pixcir_ts_touch_data)) {
>> +             dev_err(&ts->client->dev,
>> +                             "pixcir_ts:Unable get the touch info\n");
>> +             return;
>> +     }
>
> Do you need 2 transactions? Can you use i2c_transfer() here?

ok.
>
>> +
>> +     fingers = ts->touch_data.touch_fingers & 0x07;
>> +     if (fingers > 0) {
>> +             for (i = 0; i < fingers; i++) {
>> +                     /*Get the touch position*/
>> +                     input_report_abs(ts->input_dev, ABS_MT_POSITION_X,
>> +                                     ts->touch_data.point[i].posx);
>> +                     input_report_abs(ts->input_dev, ABS_MT_POSITION_Y,
>> +                                     ts->touch_data.point[i].posy);
>> +
>> +                     input_report_key(ts->input_dev, ABS_MT_TRACKING_ID,
>> +                                     ts->touch_data.point[i].id);
>> +                     input_report_abs(ts->input_dev,
>> +                                     ABS_MT_TOUCH_MAJOR, TOUCH_MAJOR_MAX);
>> +                     input_report_abs(ts->input_dev,
>> +                                     ABS_MT_WIDTH_MAJOR, WIDTH_MAJOR_MAX);
>> +                     input_mt_sync(ts->input_dev);
>
> Any chance we could use the B flavor of MT protocol?

i am sorry i missed some, what do you mean for B flavor ?

>
>> +             }
>> +     } else
>> +             input_mt_sync(ts->input_dev);
>> +
>> +     input_sync(ts->input_dev);
>> +}
>> +
>> +static irqreturn_t pixcir_ts_irq_handler(int irq, void *dev_id)
>> +{
>> +     struct pixcir_ts_data *ts = dev_id;
>> +
>> +     pixcir_ts_report_event(ts);
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int pixcir_ts_suspend(struct device *dev)
>> +{
>> +     struct i2c_client *client = to_i2c_client(dev);
>> +
>> +     if (device_may_wakeup(&client->dev))
>> +             enable_irq_wake(client->irq);
>> +
>> +     return 0;
>> +}
>> +
>> +static int pixcir_ts_resume(struct device *dev)
>> +{
>> +     struct i2c_client *client = to_i2c_client(dev);
>> +
>> +     if (device_may_wakeup(&client->dev))
>> +             disable_irq_wake(client->irq);
>> +
>> +     return 0;
>> +}
>> +
>> +static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
>> +                     pixcir_ts_suspend, pixcir_ts_resume);
>> +#endif
>> +
>> +static int pixcir_ts_probe(struct i2c_client *client,
>> +                     const struct i2c_device_id *id)
>> +{
>> +     struct pixcir_ts_data *ts;
>> +     struct input_dev *input_dev;
>> +     struct device_node *np = client->dev.of_node;
>> +     u8 tmp = 0;
>> +     int ret;
>> +
>> +     if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
>> +             return -ENODEV;
>> +
>> +     ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
>> +     if (!ts)
>> +             return -ENOMEM;
>> +     ts->client = client;
>> +     i2c_set_clientdata(client, ts);
>> +
>> +     ts->touch_pin = of_get_named_gpio(np, "touch-gpio", 0);
>> +     if (!gpio_is_valid(ts->touch_pin)) {
>> +             dev_err(&client->dev, "invalid touch_pin supplied\n");
>> +             return -EINVAL;
>> +     }
>> +     client->irq = gpio_to_irq(ts->touch_pin);
>
> This should be done by the code that sets up i2c client, this driver
> should simply use client->irq, not set it up.

the driver is based on DT. so here i guess the node should put right
interrupt_parent to a gpio controller and fill right interrupts prop
to fix it.
non-DT users can still fill i2c board_info in mach.

>
>> +
>> +     input_dev = input_allocate_device();
>> +     if (!input_dev) {
>> +             ret = -ENOMEM;
>> +             goto err_free_mem;
>> +     }
>> +
>> +     /* if the client exists, this i2c transfer should be ok */
>> +     ret = i2c_master_send(ts->client, &tmp, 1);
>> +     if (ret != 1)
>> +             goto err_free_mem;
>> +
>> +     i2c_set_clientdata(client, ts);
>> +     input_set_drvdata(input_dev, ts);
>> +     input_dev->name = "tangoc-touchscreen";
>> +     input_dev->id.bustype = BUS_I2C;
>> +     input_dev->dev.parent = &client->dev;
>> +     set_bit(EV_SYN, input_dev->evbit);
>> +     set_bit(EV_ABS, input_dev->evbit);
>> +     set_bit(ABS_MT_TOUCH_MAJOR, input_dev->absbit);
>> +     set_bit(ABS_MT_WIDTH_MAJOR, input_dev->absbit);
>> +     set_bit(ABS_MT_POSITION_X, input_dev->absbit);
>> +     set_bit(ABS_MT_POSITION_Y, input_dev->absbit);
>> +     set_bit(ABS_MT_TRACKING_ID, input_dev->absbit);
>> +     set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
>> +     input_set_abs_params(input_dev, ABS_MT_POSITION_X,
>> +                     TOUCHSCREEN_MINX, TOUCHSCREEN_MAXX, 0, 0);
>> +     input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
>> +                     TOUCHSCREEN_MINY, TOUCHSCREEN_MAXY, 0, 0);
>> +     input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
>> +                     0, TOUCH_MAJOR_MAX, 0, 0);
>> +     input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR,
>> +                     0, WIDTH_MAJOR_MAX, 0, 0);
>> +     input_set_abs_params(input_dev, ABS_MT_TRACKING_ID,
>> +                     0, TRACKING_ID_MAX, 0, 0);
>> +
>> +     ret = devm_request_threaded_irq(&client->dev,
>> +             client->irq,
>> +             NULL, pixcir_ts_irq_handler,
>> +             IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
>> +             client->name, ts);
>> +     if (ret) {
>> +             dev_err(&client->dev, "\nFailed to register interrupt\n");
>> +             goto err_free_mem;
>> +     }
>> +
>> +     ts->input_dev = input_dev;
>
> You need to make this assignment earlier, otherwise, if somebody is
> touching the screen you'll get a nice oops here.

ok.

>
>> +     ret = input_register_device(ts->input_dev);
>> +     if (ret) {
>> +             dev_err(&client->dev, "Unable to register %s input device\n",
>> +                     input_dev->name);
>> +             goto err_free_mem;
>> +     }
>> +     device_init_wakeup(&client->dev, 1);
>> +
>> +     return 0;
>> +
>> +err_free_mem:
>> +     input_free_device(input_dev);
>> +     return ret;
>> +}
>> +
>> +static int pixcir_ts_remove(struct i2c_client *client)
>> +{
>> +     struct pixcir_ts_data *ts = i2c_get_clientdata(client);
>> +     device_init_wakeup(&client->dev, 0);
>> +     input_unregister_device(ts->input_dev);
>
> This is so going to bomb because input device disappears but IRQ is not
> going to be unregistered till later. The easiest way would be to use
> devm_input_allocate_device() and get rid of input_unregister_device()
> altogether.

ok.

>
>> +     return 0;
>> +}
>> +
>> +static const struct i2c_device_id pixcir_ts_id[] = {
>> +     { "tangoc-ts", 0 },
>> +     { }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(i2c, pixcir_ts_id);
>> +
>> +static struct i2c_driver pixcir_ts_driver = {
>> +     .driver = {
>> +             .name   = "tangoc-ts",
>> +             .owner  = THIS_MODULE,
>> +#ifdef CONFIG_PM_SLEEP
>> +             .pm     = &pixcir_dev_pm_ops,
>> +#endif
>> +     },
>> +     .id_table       = pixcir_ts_id,
>> +     .probe          = pixcir_ts_probe,
>> +     .remove         = pixcir_ts_remove,
>> +};
>> +
>> +module_i2c_driver(pixcir_ts_driver);
>> +
>> +MODULE_AUTHOR("Lisai Wang <Lisai.Wang@csr.com>, Guoying Zhang <Guoying.Zhang@csr.com>");
>> +MODULE_DESCRIPTION("PIXCIR-TangoC 5 points touch controller Driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.7.5.4
>>
>
> Thanks.
>
> --
> Dmitry

-barry