Re: [PATCH 2/3] Input: of_touchscreen - fix setting max values on X/Y axis

[Dmitry Torokhov]

Hi Roger,

On Tue, Jul 07, 2015 at 12:37:31PM +0300, Roger Quadros wrote:
> Hi Dmitry,
> 
> On 07/07/15 03:27, Dmitry Torokhov wrote:
> >The binding specification says that "touchscreen-size-x" and "-y" specify
> >horizontal and vertical resolution of the touchscreen and therefore maximum
> >absolute coordinates should be reduced by 1 since we are starting with 0.
> >
> >Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> >---
> >  drivers/input/touchscreen/of_touchscreen.c | 10 ++++++----
> >  1 file changed, 6 insertions(+), 4 deletions(-)
> >
> >diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
> >index 759cf4b..50bc0f2 100644
> >--- a/drivers/input/touchscreen/of_touchscreen.c
> >+++ b/drivers/input/touchscreen/of_touchscreen.c
> >@@ -71,23 +71,25 @@ void touchscreen_parse_of_params(struct input_dev *dev, bool multitouch)
> >
> >  	axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
> >  	data_present = touchscreen_get_prop_u32(np, "touchscreen-size-x",
> >-						input_abs_get_max(dev, axis),
> >+						input_abs_get_max(dev,
> >+								  axis) + 1,
> 
> Why do we need to pass default_value to touchscreen_get_prop_u32()?
> If the property doesn't exist we are not updating the parameter
> anyway right?

The binding can specify max, fuzz, both, or neither. If only one is
specified we do not want to "undo" whatever the driver did (for example
tsc2005 sets up the default maximums before trying to parse OF), so we
fetch the current value and pass it on as default one.

> 
> >  						&maximum) |
> >  		       touchscreen_get_prop_u32(np, "touchscreen-fuzz-x",
> >  						input_abs_get_fuzz(dev, axis),
> >  						&fuzz);
> >  	if (data_present)
> >-		touchscreen_set_params(dev, axis, maximum, fuzz);
> >+		touchscreen_set_params(dev, axis, maximum - 1, fuzz);
> >
> >  	axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y;
> >  	data_present = touchscreen_get_prop_u32(np, "touchscreen-size-y",
> >-						input_abs_get_max(dev, axis),
> >+						input_abs_get_max(dev,
> >+								  axis) + 1,
> >  						&maximum) |
> >  		       touchscreen_get_prop_u32(np, "touchscreen-fuzz-y",
> >  						input_abs_get_fuzz(dev, axis),
> >  						&fuzz);
> >  	if (data_present)
> >-		touchscreen_set_params(dev, axis, maximum, fuzz);
> >+		touchscreen_set_params(dev, axis, maximum - 1, fuzz);
> >
> >  	axis = multitouch ? ABS_MT_PRESSURE : ABS_PRESSURE;
> >  	data_present = touchscreen_get_prop_u32(np, "touchscreen-max-pressure",
> >
> 

Thanks.

-- 
Dmitry
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