On 12/18/2013 07:39 PM, Dmitry Torokhov wrote:
> Hi Roger,
> 
> On Wed, Dec 18, 2013 at 02:51:12PM +0530, Roger Quadros wrote:
>> Provide device tree support and binding information.
>> Change platform data parameters from x/y_max to x/y_size..
> 
> I'd rather keep them as they were.

OK.

> 
>>
>> Signed-off-by: Roger Quadros <rog...@ti.com>
>> Acked-by: Mugunthan V N <mugunthan...@ti.com>
>> ---
>>  .../bindings/input/touchscreen/pixcir_i2c_ts.txt   | 26 ++++++++
>>  drivers/input/touchscreen/pixcir_i2c_ts.c          | 77 
>> ++++++++++++++++++++--
>>  include/linux/input/pixcir_ts.h                    |  5 +-
>>  3 files changed, 101 insertions(+), 7 deletions(-)
>>  create mode 100644 
>> Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
>>
>> diff --git 
>> a/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt 
>> b/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
>> new file mode 100644
>> index 0000000..c0b0b270
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt
>> @@ -0,0 +1,26 @@
>> +* Pixcir I2C touchscreen controllers
>> +
>> +Required properties:
>> +- compatible: must be "pixcir,pixcir_ts"
>> +- reg: I2C address of the chip
>> +- interrupts: interrupt to which the chip is connected
>> +- attb-gpio: GPIO connected to the ATTB line of the chip
>> +- x-size: horizontal resolution of touchscreen
>> +- y-size: vertical resolution of touchscreen
>> +
>> +Example:
>> +
>> +    i2c@00000000 {
>> +            /* ... */
>> +
>> +            pixcir_ts@5c {
>> +                    compatible = "pixcir,pixcir_ts";
>> +                    reg = <0x5c>;
>> +                    interrupts = <2 0>;
>> +                    attb-gpio = <&gpf 2 0 2>;
>> +                    x-size = <800>;
>> +                    y-size = <600>;
>> +            };
>> +
>> +            /* ... */
>> +    };
>> diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c 
>> b/drivers/input/touchscreen/pixcir_i2c_ts.c
>> index 6cc6b36..3a447c9 100644
>> --- a/drivers/input/touchscreen/pixcir_i2c_ts.c
>> +++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
>> @@ -24,6 +24,10 @@
>>  #include <linux/i2c.h>
>>  #include <linux/input.h>
>>  #include <linux/input/pixcir_ts.h>
>> +#include <linux/gpio.h>
>> +#include <linux/of.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/of_device.h>
>>  
>>  struct pixcir_i2c_ts_data {
>>      struct i2c_client *client;
>> @@ -125,15 +129,65 @@ static int pixcir_i2c_ts_resume(struct device *dev)
>>  static SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
>>                       pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
>>  
>> +#if defined(CONFIG_OF)
> 
> #ifdef is preferred for simple conditions.
> 
>> +static const struct of_device_id pixcir_of_match[];
>> +
>> +static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
>> +{
>> +    struct pixcir_ts_platform_data *pdata;
>> +    struct device_node *np = dev->of_node;
>> +    const struct of_device_id *match;
>> +
>> +    match = of_match_device(of_match_ptr(pixcir_of_match), dev);
>> +    if (!match)
>> +            return ERR_PTR(-EINVAL);
> 
> Why do you need an explicit match here?
> 

Right, it is not needed here for this patch but used later in patch 6
to get chip specific data. I'll fix this while re-arranging the patches.

>> +
>> +    pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
>> +    if (!pdata)
>> +            return ERR_PTR(-ENOMEM);
>> +
>> +    pdata->gpio_attb = of_get_named_gpio(np, "attb-gpio", 0);
>> +    if (!gpio_is_valid(pdata->gpio_attb))
>> +            dev_err(dev, "Failed to get ATTB GPIO\n");
>> +
>> +    if (of_property_read_u32(np, "x-size", &pdata->x_size)) {
>> +            dev_err(dev, "Failed to get x-size property\n");
>> +            return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    if (of_property_read_u32(np, "y-size", &pdata->y_size)) {
>> +            dev_err(dev, "Failed to get y-size property\n");
>> +            return ERR_PTR(-EINVAL);
>> +    }
>> +
>> +    dev_dbg(dev, "%s: x %d, y %d, gpio %d\n", __func__,
>> +                            pdata->x_size, pdata->y_size, pdata->gpio_attb);
>> +
>> +    return pdata;
>> +}
>> +#else
>> +static struct pixcir_ts_platform_data *pixcir_parse_dt(struct device *dev)
>> +{
>> +    return NULL;
> 
> This should be
> 
>       return ERR_PTR(-EINVAL);
> 
> since you test it with IS_ERR() later.

OK.

> 
>> +}
>> +#endif
>> +
>>  static int pixcir_i2c_ts_probe(struct i2c_client *client,
>>                                       const struct i2c_device_id *id)
>>  {
>>      const struct pixcir_ts_platform_data *pdata = client->dev.platform_data;
>> +    struct device *dev = &client->dev;
>> +    struct device_node *np = dev->of_node;
>>      struct pixcir_i2c_ts_data *tsdata;
>>      struct input_dev *input;
>>      int error;
>>  
>> -    if (!pdata) {
>> +    if (np) {
>> +            pdata = pixcir_parse_dt(dev);
>> +            if (IS_ERR(pdata))
>> +                    return PTR_ERR(pdata);
> 
> We should be favoring kernel-provided platform data if it is pesent even
> if there is dt-data available. This way user can override firmware,m if
> needed.
> 
OK. But how can the user override kernel provided platform data? Can't device
tree overlays be used to patch DT data in the same fashion.

I've not tried either so I don't know which one is more user friendly.

>> +
>> +    } else if (!pdata) {
>>              dev_err(&client->dev, "platform data not defined\n");
>>              return -EINVAL;
>>      }
>> @@ -157,10 +211,14 @@ static int pixcir_i2c_ts_probe(struct i2c_client 
>> *client,
>>      __set_bit(EV_KEY, input->evbit);
>>      __set_bit(EV_ABS, input->evbit);
>>      __set_bit(BTN_TOUCH, input->keybit);
>> -    input_set_abs_params(input, ABS_X, 0, pdata->x_max, 0, 0);
>> -    input_set_abs_params(input, ABS_Y, 0, pdata->y_max, 0, 0);
>> -    input_set_abs_params(input, ABS_MT_POSITION_X, 0, pdata->x_max, 0, 0);
>> -    input_set_abs_params(input, ABS_MT_POSITION_Y, 0, pdata->y_max, 0, 0);
>> +    input_set_abs_params(input, ABS_X,
>> +                                    0, pdata->x_size - 1, 0, 0);
>> +    input_set_abs_params(input, ABS_Y,
>> +                                    0, pdata->y_size - 1, 0, 0);
>> +    input_set_abs_params(input, ABS_MT_POSITION_X,
>> +                                    0, pdata->x_size - 1, 0, 0);
>> +    input_set_abs_params(input, ABS_MT_POSITION_Y,
>> +                                    0, pdata->y_size - 1, 0, 0);
>>  
>>      input_set_drvdata(input, tsdata);
>>  
>> @@ -211,11 +269,20 @@ static const struct i2c_device_id pixcir_i2c_ts_id[] = 
>> {
>>  };
>>  MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
>>  
>> +#if defined(CONFIG_OF)
>> +static const struct of_device_id pixcir_of_match[] = {
>> +    { .compatible = "pixcir,pixcir_ts", },
>> +    { }
>> +};
>> +MODULE_DEVICE_TABLE(of, pixcir_of_match);
>> +#endif
> 
> #ifdef is preferred for simple conditions.
> 
OK.

>> +
>>  static struct i2c_driver pixcir_i2c_ts_driver = {
>>      .driver = {
>>              .owner  = THIS_MODULE,
>>              .name   = "pixcir_ts",
>>              .pm     = &pixcir_dev_pm_ops,
>> +            .of_match_table = of_match_ptr(pixcir_of_match),
>>      },
>>      .probe          = pixcir_i2c_ts_probe,
>>      .remove         = pixcir_i2c_ts_remove,
>> diff --git a/include/linux/input/pixcir_ts.h 
>> b/include/linux/input/pixcir_ts.h
>> index 7163d91..b34ff7e 100644
>> --- a/include/linux/input/pixcir_ts.h
>> +++ b/include/linux/input/pixcir_ts.h
>> @@ -3,8 +3,9 @@
>>  
>>  struct pixcir_ts_platform_data {
>>      int (*attb_read_val)(void);
>> -    int x_max;
>> -    int y_max;
>> +    unsigned int x_size;    /* X axis resolution */
>> +    unsigned int y_size;    /* Y axis resolution */
>> +    int gpio_attb;          /* GPIO connected to ATTB line */
>>  };
> 
> OK, it looks like the series were split awkwardly: you are defining data
> that is used by follow-up patches and its purpose is unclear when
> reviewing patch-by-patch. I'd recommend rearranging so that DT support
> patch is the very last in the series.
> 
Got it.

>>  
>>  #endif
>> -- 
>> 1.8.3.2

cheers,
-roger
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