[PATCH 2/2] input: wacom - Pass touch resolution to clients through input_absinfo

[PATCH 2/2] input: wacom - Pass touch resolution to clients through input_absinfo

[Ping Cheng]

Fixed the workaround used for kernels older than 2.6.35.

Signed-off-by: Ping Cheng <pingc@wacom.com>
---
 drivers/input/tablet/wacom_wac.c |   18 +++++++++++++++---
 1 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index f44c822..497d0ba 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -1105,7 +1105,7 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 				    struct wacom_wac *wacom_wac)
 {
 	struct wacom_features *features = &wacom_wac->features;
-	int i;
+	int i, res;
 
 	input_dev->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 
@@ -1228,8 +1228,13 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 	case TABLETPC:
 		if (features->device_type == BTN_TOOL_DOUBLETAP ||
 		    features->device_type == BTN_TOOL_TRIPLETAP) {
-			input_set_abs_params(input_dev, ABS_RX, 0, features->x_phy, 0, 0);
-			input_set_abs_params(input_dev, ABS_RY, 0, features->y_phy, 0, 0);
+			/* set touch resolution in points/mm */
+			res = features->x_phy/100;
+			input_abs_set_res(input_dev, ABS_X,
+					    features->x_max/res);
+			res = features->y_phy/100;
+			input_abs_set_res(input_dev, ABS_Y,
+					    features->y_max/res);
 			__set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
 		}
 
@@ -1272,6 +1277,13 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 			input_set_abs_params(input_dev, ABS_MT_PRESSURE,
 					     0, features->pressure_max,
 					     features->pressure_fuzz, 0);
+			/* set touch resolution in points/mm */
+			res = features->x_phy/100;
+			input_abs_set_res(input_dev, ABS_X,
+					    features->x_max/res);
+			res = features->y_phy/100;
+			input_abs_set_res(input_dev, ABS_Y,
+					    features->y_max/res);
 		} else if (features->device_type == BTN_TOOL_PEN) {
 			__set_bit(BTN_TOOL_RUBBER, input_dev->keybit);
 			__set_bit(BTN_TOOL_PEN, input_dev->keybit);
-- 
1.7.3.4

Re: [2/2] input: wacom - Pass touch resolution to clients through input_absinfo

[Henrik Rydberg]

Hi Ping,

> @@ -1228,8 +1228,13 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
>  	case TABLETPC:
>  		if (features->device_type == BTN_TOOL_DOUBLETAP ||
>  		    features->device_type == BTN_TOOL_TRIPLETAP) {
> -			input_set_abs_params(input_dev, ABS_RX, 0, features->x_phy, 0, 0);
> -			input_set_abs_params(input_dev, ABS_RY, 0, features->y_phy, 0, 0);
> +			/* set touch resolution in points/mm */
> +			res = features->x_phy/100;
> +			input_abs_set_res(input_dev, ABS_X,
> +					    features->x_max/res);

It seems to me the construction above looses precision twice for no
apparent reason. How about instead use "100 * features->x_max /
features->x_phy"? Besides, it is a bit unfortunate that "res" is short
for both result and resolution. Finally, are the physical dimensions
actually presented in 100ths of millimeters?

Thanks,
Henrik

Re: [2/2] input: wacom - Pass touch resolution to clients through input_absinfo

[Ping Cheng]

On Mon, Jan 24, 2011 at 6:40 AM, Henrik Rydberg <rydberg@euromail.se> wrote:
> Hi Ping,
>
>> @@ -1228,8 +1228,13 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
>>       case TABLETPC:
>>               if (features->device_type == BTN_TOOL_DOUBLETAP ||
>>                   features->device_type == BTN_TOOL_TRIPLETAP) {
>> -                     input_set_abs_params(input_dev, ABS_RX, 0, features->x_phy, 0, 0);
>> -                     input_set_abs_params(input_dev, ABS_RY, 0, features->y_phy, 0, 0);
>> +                     /* set touch resolution in points/mm */
>> +                     res = features->x_phy/100;
>> +                     input_abs_set_res(input_dev, ABS_X,
>> +                                         features->x_max/res);
>
> It seems to me the construction above looses precision twice for no
> apparent reason.

Well, there was a reason (logically instead of mathematically though):
features->x_phy/100 gives us the physical size of the touch area in
mm.

> How about instead use "100 * features->x_max /
> features->x_phy"?

Sure.

> Besides, it is a bit unfortunate that "res" is short
> for both result and resolution.

Resolution is defined as __s32 in input_absinfo. How about we use __s32 then?

> Finally, are the physical dimensions
> actually presented in 100ths of millimeters?

Well, the protocol says it is in thousandth of a centimeter. So, 100th
of a mm is right too.

Thank you for the comments.

Ping
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Re: [2/2] input: wacom - Pass touch resolution to clients through input_absinfo

[Dmitry Torokhov]

On Mon, Jan 24, 2011 at 10:18:54AM -0800, Ping Cheng wrote:
> On Mon, Jan 24, 2011 at 6:40 AM, Henrik Rydberg <rydberg@euromail.se> wrote:
> > Hi Ping,
> >
> >> @@ -1228,8 +1228,13 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
> >>       case TABLETPC:
> >>               if (features->device_type == BTN_TOOL_DOUBLETAP ||
> >>                   features->device_type == BTN_TOOL_TRIPLETAP) {
> >> -                     input_set_abs_params(input_dev, ABS_RX, 0, features->x_phy, 0, 0);
> >> -                     input_set_abs_params(input_dev, ABS_RY, 0, features->y_phy, 0, 0);
> >> +                     /* set touch resolution in points/mm */
> >> +                     res = features->x_phy/100;
> >> +                     input_abs_set_res(input_dev, ABS_X,
> >> +                                         features->x_max/res);
> >
> > It seems to me the construction above looses precision twice for no
> > apparent reason.
> 
> Well, there was a reason (logically instead of mathematically though):
> features->x_phy/100 gives us the physical size of the touch area in
> mm.
> 
> > How about instead use "100 * features->x_max /
> > features->x_phy"?
> 
> Sure.
> 
> > Besides, it is a bit unfortunate that "res" is short
> > for both result and resolution.
> 
> Resolution is defined as __s32 in input_absinfo. How about we use __s32 then?

input_abs_set_res() takes and int argument so keep it int  (or just
embed the expression into the call and forgo 'res').

-- 
Dmitry
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Re: [2/2] input: wacom - Pass touch resolution to clients through input_absinfo

[Ping Cheng]

On Mon, Jan 24, 2011 at 10:36 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Mon, Jan 24, 2011 at 10:18:54AM -0800, Ping Cheng wrote:
>> On Mon, Jan 24, 2011 at 6:40 AM, Henrik Rydberg <rydberg@euromail.se> wrote:
>> > Hi Ping,
>> >
>> >> @@ -1228,8 +1228,13 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
>> >>       case TABLETPC:
>> >>               if (features->device_type == BTN_TOOL_DOUBLETAP ||
>> >>                   features->device_type == BTN_TOOL_TRIPLETAP) {
>> >> -                     input_set_abs_params(input_dev, ABS_RX, 0, features->x_phy, 0, 0);
>> >> -                     input_set_abs_params(input_dev, ABS_RY, 0, features->y_phy, 0, 0);
>> >> +                     /* set touch resolution in points/mm */
>> >> +                     res = features->x_phy/100;
>> >> +                     input_abs_set_res(input_dev, ABS_X,
>> >> +                                         features->x_max/res);
>> >
>> > It seems to me the construction above looses precision twice for no
>> > apparent reason.
>>
>> Well, there was a reason (logically instead of mathematically though):
>> features->x_phy/100 gives us the physical size of the touch area in
>> mm.
>>
>> > How about instead use "100 * features->x_max /
>> > features->x_phy"?
>>
>> Sure.
>>
>> > Besides, it is a bit unfortunate that "res" is short
>> > for both result and resolution.
>>
>> Resolution is defined as __s32 in input_absinfo. How about we use __s32 then?
>
> input_abs_set_res() takes and int argument so keep it int  (or just
> embed the expression into the call and forgo 'res').

I added 'res' to avoid confusion hence questions about the formula. I
am still questioned ;).

 I'll forgo 'res' in v2. Thank you for the suggestions.

Ping
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