A question about touchscreen absmax value

A question about touchscreen absmax value

[Joonyoung Shim]

Hi, all.

I have a question about touchscreen resolution. My touchscreen device
can report the position from 0 to 1023 of x and y coordinates, so i
setted the absmax of input device to 1023. BTW, i only can get from 0 to 
479 x position and to 799 y position because the LCD resolution of the
target is 480 x 800. I wonder which value is setted to the absmax - 479
and 799 or 1023.

Re: A question about touchscreen absmax value

[Dmitry Torokhov]

Hi Joonyoung,

On Mon, Nov 16, 2009 at 10:53:18AM +0900, Joonyoung Shim wrote:
> Hi, all.
> 
> I have a question about touchscreen resolution. My touchscreen device
> can report the position from 0 to 1023 of x and y coordinates, so i
> setted the absmax of input device to 1023. BTW, i only can get from 0 to 
> 479 x position and to 799 y position because the LCD resolution of the
> target is 480 x 800. I wonder which value is setted to the absmax - 479
> and 799 or 1023.

I believe driver should, by default, set absmin and absmax to match the
limits of the hardware/protocol. In your case it would be 1023. The
driver may choose to accept additional infromation from platform data, if
present, you can also adjust absmin/absmax etc via ioctl durng the
bootup sequence.

Hope this helps.

-- 
Dmitry

Re: A question about touchscreen absmax value

[Joonyoung Shim]

On 11/17/2009 2:12 AM, Dmitry Torokhov wrote:
> Hi Joonyoung,
> 
> On Mon, Nov 16, 2009 at 10:53:18AM +0900, Joonyoung Shim wrote:
>> Hi, all.
>>
>> I have a question about touchscreen resolution. My touchscreen device
>> can report the position from 0 to 1023 of x and y coordinates, so i
>> setted the absmax of input device to 1023. BTW, i only can get from 0 to 
>> 479 x position and to 799 y position because the LCD resolution of the
>> target is 480 x 800. I wonder which value is setted to the absmax - 479
>> and 799 or 1023.
> 
> I believe driver should, by default, set absmin and absmax to match the
> limits of the hardware/protocol. In your case it would be 1023. The
> driver may choose to accept additional infromation from platform data, if
> present, you can also adjust absmin/absmax etc via ioctl durng the
> bootup sequence.

Hmm, i get the resolution information from platform data, so i can 
set absmax values from platform data. Is it ok?

Thanks for reply.

Re: A question about touchscreen absmax value

[Dmitry Torokhov]

On Tue, Nov 17, 2009 at 12:00:08PM +0900, Joonyoung Shim wrote:
> On 11/17/2009 2:12 AM, Dmitry Torokhov wrote:
> > Hi Joonyoung,
> > 
> > On Mon, Nov 16, 2009 at 10:53:18AM +0900, Joonyoung Shim wrote:
> >> Hi, all.
> >>
> >> I have a question about touchscreen resolution. My touchscreen device
> >> can report the position from 0 to 1023 of x and y coordinates, so i
> >> setted the absmax of input device to 1023. BTW, i only can get from 0 to 
> >> 479 x position and to 799 y position because the LCD resolution of the
> >> target is 480 x 800. I wonder which value is setted to the absmax - 479
> >> and 799 or 1023.
> > 
> > I believe driver should, by default, set absmin and absmax to match the
> > limits of the hardware/protocol. In your case it would be 1023. The
> > driver may choose to accept additional infromation from platform data, if
> > present, you can also adjust absmin/absmax etc via ioctl durng the
> > bootup sequence.
> 
> Hmm, i get the resolution information from platform data, so i can 
> set absmax values from platform data. Is it ok?
> 

Sure, if there is only one possible configuration for the device on a
given platform - yes.

-- 
Dmitry

Re: A question about touchscreen absmax value

[Joonyoung Shim]

On 11/17/2009 2:48 PM, Dmitry Torokhov wrote:
> On Tue, Nov 17, 2009 at 12:00:08PM +0900, Joonyoung Shim wrote:
>> On 11/17/2009 2:12 AM, Dmitry Torokhov wrote:
>>> Hi Joonyoung,
>>>
>>> On Mon, Nov 16, 2009 at 10:53:18AM +0900, Joonyoung Shim wrote:
>>>> Hi, all.
>>>>
>>>> I have a question about touchscreen resolution. My touchscreen device
>>>> can report the position from 0 to 1023 of x and y coordinates, so i
>>>> setted the absmax of input device to 1023. BTW, i only can get from 0 to 
>>>> 479 x position and to 799 y position because the LCD resolution of the
>>>> target is 480 x 800. I wonder which value is setted to the absmax - 479
>>>> and 799 or 1023.
>>> I believe driver should, by default, set absmin and absmax to match the
>>> limits of the hardware/protocol. In your case it would be 1023. The
>>> driver may choose to accept additional infromation from platform data, if
>>> present, you can also adjust absmin/absmax etc via ioctl durng the
>>> bootup sequence.
>> Hmm, i get the resolution information from platform data, so i can 
>> set absmax values from platform data. Is it ok?
>>
> 
> Sure, if there is only one possible configuration for the device on a
> given platform - yes.
> 

OK, it is helpful me.

Thanks.