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

Zumeng Chen zumeng.chen at windriver.com
Wed Jun 20 01:28:46 EDT 2012

于 2012年06月14日 14:59, Zumeng Chen 写道:
> 于 2012年06月14日 14:31, Hiremath, Vaibhav 写道:
>> On Thu, Jun 14, 2012 at 10:16:55, Zumeng Chen wrote:
>>> 于 2012年06月13日 20:18, Hiremath, Vaibhav 写道:
>>>> On Wed, Jun 13, 2012 at 07:14:10, Zumeng Chen wrote:
>>>>> From: Zumeng Chen<zumeng.chen at windriver.com>
>>>>> 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<zumeng.chen at windriver.com>
>>>>> Signed-off-by: Syed Mohammed Khasim<khasim at ti.com>
>>>>> ---
>>>>>   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
>>>> Zumeng,
>>>> With my sign-off you are changing the original code, that too
>>>> without my sign-off and ack.
>>>> I wouldn't mind you to submit patches from my tree, but the expectation is
>>>> if you are changing the original code, it should be under your sign-off.
>>> Thanks, good to learn. I'll remove in next time.
>>>> Coming to the patch, #ifdef in driver is not recommended, and this 10msec
>>>> delay is specific to OMAP GPIO and driver should not be aware of this,
>>>> that's where you will find the original patch handling it in board file.
>>> According to the git blame of the board-omap3evm.c I think
>>> 96974a24 did a good thing to all the related codes for omap3
>>> boards. So I think we can call board and driver as BSP level :-)
>>> If #ifdef in driver can save many codes, I guess it's deserved.
>> No, not really.
>> In the same commit, the debounce time is already handled as an argument to 
>> the function omap_ads7846_init(), and that’s the way it should be.
> That means you'd like to implement the same get_pendown_state for every
> omap3 board? Currently, board_pdata is NULL.
> And actually, the reason why I agree 96974a24 is that get_pendown_state
> for all omap3 boards is the common chip level gpio operations. so I think
> we should set debounce for them in one common point.
> But since Igor and you don't like them, I have created and tested the
> attachment
> patch, and I'd like Mike to check if convenience too
> But obviously there are more codes than mine before :-)
Hi Mike,

I'll send V3 with the change on the attachment to you for 5/5,
if you happen to get it, it's high appreciated to review it.

> Regards,
> Zumeng
>> So no need for #ifdefs in driver...
>> Thanks,
>> Vaibhav

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