Re: [PATCH 3/4] Input: goodix - Tweak configuration to use passed in touchscreen resolution

[Bastien Nocera]

On Thu, 2016-10-20 at 14:59 -0500, Franklin S Cooper Jr wrote:
> Some goodix touchscreen controllers aren't programed properly to
> match the
> display panel it is used on. Although the defaults may largely work
> it is
> also likely that the screen resolution will be incorrect. Therefore,
> add support to allow via DT for the touchscreen resolution to be set
> and
> reprogram the controller to use this updated resolution.
> 
> Signed-off-by: Franklin S Cooper Jr <fcooper@xxxxxx>
> ---
> Â.../bindings/input/touchscreen/goodix.txtÂÂÂÂÂÂÂÂÂÂ|ÂÂ2 ++
> Âdrivers/input/touchscreen/goodix.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ| 26
> +++++++++++++++++++++-
> Â2 files changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git
> a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> index c98757a..ebc7cb7 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt
> @@ -19,6 +19,8 @@ Optional properties:
> Â			ÂÂinterrupt gpio pin as output to reset the
> device.
> Â - reset-gpios		: GPIO pin used for reset
> Â
> + - touchscreen-size-xÂÂÂÂÂÂ: horizontal resolution of touchscreen
> (in pixels)
> + - touchscreen-size-yÂÂÂÂÂÂ: vertical resolution of touchscreen (in
> pixels)
> Â - touchscreen-inverted-xÂÂ: X axis is inverted (boolean)
> Â - touchscreen-inverted-yÂÂ: Y axis is inverted (boolean)
> Â - touchscreen-swapped-x-y : X and Y axis are swapped (boolean)
> diff --git a/drivers/input/touchscreen/goodix.c
> b/drivers/input/touchscreen/goodix.c
> index 01e12f8..c2428e1 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -496,6 +496,10 @@ static void goodix_tweak_config(struct
> goodix_ts_data *ts)
> Â		return;
> Â	}
> Â
> +	/* Setting X and Y Resolution */
> +	put_unaligned_le16(ts->abs_x_max, &config[RESOLUTION_LOC]);
> +	put_unaligned_le16(ts->abs_y_max, &config[RESOLUTION_LOC +
> 2]);
> +
> Â	check_sum = goodix_calculate_checksum(ts->cfg_len, config);
> Â
> Â	config[raw_cfg_len] = check_sum;
> @@ -669,6 +673,8 @@ static int goodix_request_input_dev(struct
> goodix_ts_data *ts)
> Âstatic int goodix_configure_dev(struct goodix_ts_data *ts)
> Â{
> Â	int error;
> +	bool alter_config = false;
> +	u32 max_x, max_y;
> Â
> Â	ts->swapped_x_y = device_property_read_bool(&ts->client-
> >dev,
> Â						ÂÂÂÂ"touchscreen-
> swapped-x-y");
> @@ -676,9 +682,27 @@ static int goodix_configure_dev(struct
> goodix_ts_data *ts)
> Â						ÂÂÂ"touchscreen-
> inverted-x");
> Â	ts->inverted_y = device_property_read_bool(&ts->client->dev,
> Â						ÂÂÂ"touchscreen-
> inverted-y");
> -

No need for that linefeed removal.

> Â	goodix_read_config(ts);
> Â
> +	if (device_property_present(&ts->client->dev, "touchscreen-
> size-x") &&

Is it expected that incomplete or invalid arguments do not generate
errors? I'd expect that the presence of just one of those properties,
or...

> +	ÂÂÂÂdevice_property_present(&ts->client->dev, "touchscreen-
> size-y")) {
> +
> +		device_property_read_u32(&ts->client->dev,
> "touchscreen-size-x",
> +				&max_x);
> +
> +		device_property_read_u32(&ts->client->dev,
> "touchscreen-size-y",
> +				&max_y);
> +
> +		if (max_x > 0 && max_y > 0) {

... invalid values for those properties would throw errors (either
warnings, or lower severity messages).

> +			ts->abs_x_max = max_x;
> +			ts->abs_y_max = max_y;
> +			alter_config = true;
> +		}
> +	}
> +
> +	if (alter_config)
> +		goodix_tweak_config(ts);
> +
> Â	error = goodix_request_input_dev(ts);
> Â	if (error)
> Â		return error;