Re: [PATCH resend 1/4] of_touchscreen-helpers: Add support for inverted / swapped axis

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 27-01-16 23:45, Dmitry Torokhov wrote:
> Hi Hans,
>
> On Wed, Jan 27, 2016 at 07:25:21PM +0100, Hans de Goede wrote:
>> Extend touchscreen_parse_properties() with support for the
>> touchscreen-inverted-x/y and touchscreen-swapped-x-y properties and
>> add a touchscreen_apply_prop_to_x_y() helper function for adjusting
>> x and y coordinates to take these properties into account.
>>
>> This commit also modifies the existing callers of
>> touchscreen_parse_properties() to pass in NULL for the new third
>> argument, keeping the existing behavior.
>
> Thank you for re-sending the patches. I was wondering if we should add
> the transformation flags directly to the input devices and perform
> transformation in input core... Probably won't going to work well unless
> we start defining order in which we send events to the core.

Interesting that you mention this, I had the same thought. The problem
with doing this in the core is that we rely on the order of applying
invert then axis swapping specified in the dt binding, so it seems best
to keep this in the of helpers.

>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>   drivers/input/touchscreen/edt-ft5x06.c     |  2 +-
>>   drivers/input/touchscreen/of_touchscreen.c | 56 +++++++++++++++++++++++++++++-
>>   drivers/input/touchscreen/pixcir_i2c_ts.c  |  2 +-
>>   drivers/input/touchscreen/tsc200x-core.c   |  2 +-
>>   include/linux/input/touchscreen.h          | 16 ++++++++-
>>   5 files changed, 73 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
>> index 0b0f8c1..a97b54a 100644
>> --- a/drivers/input/touchscreen/edt-ft5x06.c
>> +++ b/drivers/input/touchscreen/edt-ft5x06.c
>> @@ -966,7 +966,7 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
>>   	input_set_abs_params(input, ABS_MT_POSITION_Y,
>>   			     0, tsdata->num_y * 64 - 1, 0, 0);
>>
>> -	touchscreen_parse_properties(input, true);
>> +	touchscreen_parse_properties(input, true, NULL);
>>
>>   	error = input_mt_init_slots(input, tsdata->max_support_points,
>>   				INPUT_MT_DIRECT);
>> diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
>> index bb6f2fe..6fd9872 100644
>> --- a/drivers/input/touchscreen/of_touchscreen.c
>> +++ b/drivers/input/touchscreen/of_touchscreen.c
>> @@ -55,12 +55,16 @@ static void touchscreen_set_params(struct input_dev *dev,
>>    * @input: input device that should be parsed
>>    * @multitouch: specifies whether parsed properties should be applied to
>>    *	single-touch or multi-touch axes
>> + * @prop: pointer to a struct touchscreen_properties into which to store
>> + *	axis swap and invert info for use with touchscreen_report_x_y();
>> + *	or NULL
>>    *
>>    * This function parses common DT properties for touchscreens and setups the
>>    * input device accordingly. The function keeps previously set up default
>>    * values if no value is specified via DT.
>>    */
>> -void touchscreen_parse_properties(struct input_dev *input, bool multitouch)
>> +void touchscreen_parse_properties(struct input_dev *input, bool multitouch,
>> +				  struct touchscreen_properties *prop)
>>   {
>>   	struct device *dev = input->dev.parent;
>>   	unsigned int axis;
>> @@ -104,5 +108,55 @@ void touchscreen_parse_properties(struct input_dev *input, bool multitouch)
>>   						&fuzz);
>>   	if (data_present)
>>   		touchscreen_set_params(input, axis, maximum, fuzz);
>> +
>> +	if (!prop)
>> +		return;
>> +
>> +	axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
>> +
>> +	prop->max_x = input_abs_get_max(input, axis);
>> +	prop->max_y = input_abs_get_max(input, axis + 1);
>> +	prop->invert_x =
>> +		device_property_read_bool(dev, "touchscreen-inverted-x");
>> +	prop->invert_y =
>> +		device_property_read_bool(dev, "touchscreen-inverted-y");
>> +	prop->swap_x_y =
>> +		device_property_read_bool(dev, "touchscreen-swapped-x-y");
>> +
>> +	if (prop->swap_x_y) {
>> +		struct input_absinfo tmp_absinfo;
>> +
>> +		tmp_absinfo = input->absinfo[axis];
>> +		input->absinfo[axis] = input->absinfo[axis + 1];
>> +		input->absinfo[axis + 1] = tmp_absinfo;
>> +	}
>>   }
>>   EXPORT_SYMBOL(touchscreen_parse_properties);
>> +
>> +/**
>> + * touchscreen_apply_prop_to_x_y - Adjust abs x and y coordinates
>> + * @prop: pointer to a struct touchscreen_properties
>> + * @x: X coordinate to apply inversion and swapping to
>> + * @y: Y coordinate to apply inversion and swapping to
>> + *
>> + * Adjust the passed in x and y values applying any axis inversion and
>> + * swapping requested in the passed in touchscreen_properties.
>> + */
>> +void touchscreen_apply_prop_to_x_y(struct touchscreen_properties *prop,
>> +				   s16 *x, s16 *y)
>
> why s16?

To match the type used in struct input_mt_pos, so that this can be
called directly on a struct input_mt_pos (something which I ended
up not doing in all of the followup patches, but probably still
useful for the future).

>> +{
>> +	if (prop->invert_x)
>> +		*x = prop->max_x - *x;
>> +
>> +	if (prop->invert_y)
>> +		*y = prop->max_y - *y;
>> +
>> +	if (prop->swap_x_y) {
>> +		s16 tmp;
>> +
>> +		tmp = *x;
>> +		*x = *y;
>> +		*y = tmp;
>
> 		swap(*x, *y);
>
>> +	}
>> +}
>> +EXPORT_SYMBOL(touchscreen_apply_prop_to_x_y);
>> diff --git a/drivers/input/touchscreen/pixcir_i2c_ts.c b/drivers/input/touchscreen/pixcir_i2c_ts.c
>> index 09523a3..f58784d 100644
>> --- a/drivers/input/touchscreen/pixcir_i2c_ts.c
>> +++ b/drivers/input/touchscreen/pixcir_i2c_ts.c
>> @@ -515,7 +515,7 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
>>   	} else {
>>   		input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
>>   		input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
>> -		touchscreen_parse_properties(input, true);
>> +		touchscreen_parse_properties(input, true, NULL);
>>   		if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
>>   		    !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
>>   			dev_err(dev, "Touchscreen size is not specified\n");
>> diff --git a/drivers/input/touchscreen/tsc200x-core.c b/drivers/input/touchscreen/tsc200x-core.c
>> index 15240c1..26e81d1 100644
>> --- a/drivers/input/touchscreen/tsc200x-core.c
>> +++ b/drivers/input/touchscreen/tsc200x-core.c
>> @@ -559,7 +559,7 @@ int tsc200x_probe(struct device *dev, int irq, __u16 bustype,
>>   	input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
>>
>>   	if (np)
>> -		touchscreen_parse_properties(input_dev, false);
>> +		touchscreen_parse_properties(input_dev, false, NULL);
>>
>>   	input_dev->open = tsc200x_open;
>>   	input_dev->close = tsc200x_close;
>> diff --git a/include/linux/input/touchscreen.h b/include/linux/input/touchscreen.h
>> index c91e137..9e6ba20 100644
>> --- a/include/linux/input/touchscreen.h
>> +++ b/include/linux/input/touchscreen.h
>> @@ -9,8 +9,22 @@
>>   #ifndef _TOUCHSCREEN_H
>>   #define _TOUCHSCREEN_H
>>
>> +#include <asm/types.h>
>
> If you are trying to add this to have s32 typedefs

Yes that is why it is there.

> then I think it is
> wrong one.

Looks like your right, do you know what the right one is ?

>
>> +
>>   struct input_dev;
>>
>> -void touchscreen_parse_properties(struct input_dev *dev, bool multitouch);
>> +struct touchscreen_properties {
>> +	s32 max_x;
>> +	s32 max_y;
>> +	bool invert_x;
>> +	bool invert_y;
>> +	bool swap_x_y;
>> +};
>> +
>> +void touchscreen_parse_properties(struct input_dev *input, bool multitouch,
>> +				  struct touchscreen_properties *prop);
>> +
>> +void touchscreen_apply_prop_to_x_y(struct touchscreen_properties *prop,
>> +				   s16 *x, s16 *y);
>>
>>   #endif
>> --
>> 2.5.0
>>
>
> Thanks.
>

Regards,

Hans