Subject: [PATCH V2 5/5] Input: ads7846: set proper debounce time in driver level

From: [email-masked] (Igor Grinberg)
Date: Wed, 13 Jun 2012 13:13:32 +0300

On 06/13/12 12:03, Zumeng Chen wrote:
> ? 2012?06?13? 15:51, Igor Grinberg ??:
>> On 06/13/12 04:44, Zumeng Chen wrote:
>>> From: Zumeng Chen<[email-masked]>
>>>
>>> If we don't set proper debouce time for ads7846, then there are
>>> flooded interrupt counters of ads7846 responding to one time
>>> touch on screen, so the driver couldn't work well.
>>>
>>> And since most OMAP3 series boards pass NULL pointer of board_pdata
>>> to omap_ads7846_init, so it's more proper to set it in driver level
>>> after having gpio_request done.
>>>
>>> This patch has been validated on 3530evm.
>>>
>>> Signed-off-by: Zumeng Chen<[email-masked]>
>>> Signed-off-by: Syed Mohammed Khasim<[email-masked]>
>>> ---
>>>   drivers/input/touchscreen/ads7846.c |    4 ++++
>>>   1 files changed, 4 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
>>> index f02028e..459ff29 100644
>>> --- a/drivers/input/touchscreen/ads7846.c
>>> +++ b/drivers/input/touchscreen/ads7846.c
>>> @@ -980,6 +980,10 @@ static int __devinit ads7846_setup_pendown(struct spi_device *spi, struct ads784
>>>           }
>>>
>>>           ts->gpio_pendown = pdata->gpio_pendown;
>>> +#ifdef CONFIG_ARCH_OMAP3
>>> +        /* 310 means about 10 microsecond for omap3 */
>>> +        gpio_set_debounce(pdata->gpio_pendown, 310);
>>> +#endif
>> Unless this concerns many boards/archs/platforms,
> Yes, this is the case.
>> I'd suggest you to implement
>> the get_pendown_state() method in the board file.
> it seems they are different way between gpio and
> get_pendown_state, and gpio way is used for omap3
> to drive ads7846, so I guess we may have to do like this.

No, this is not (and does not have to be) OMAP wide.
The decision for this is made on per-board basis.

> 
> Regards,
> Zumeng
>> If more users will need this, it can be facilitated in the driver.
>> (and of course not with the ugly ifdefs...)
>>
>>>
>>>       } else {
>>>           dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
> 
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-- 
Regards,
Igor.