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

From: [email-masked] (Igor Grinberg)
Date: Thu, 14 Jun 2012 11:06:41 +0300

On 06/14/12 10:08, Zumeng Chen wrote:
> ? 2012?06?14? 14:44, Igor Grinberg ??:
>> On 06/14/12 07:46, Zumeng Chen wrote:
>>> > ? 2012?06?13? 20:18, Hiremath, Vaibhav ??:
>>>> >> On Wed, Jun 13, 2012 at 07:14:10, 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
>>>>> >>>
>>>> >> 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, platform/board specific ifdefs in the generic driver code are never
>> deserved.
>> How about the attached patch, does it fix the problem for you?
> Sorry Igor, I just read your patch, yes, most are there, and we
> just have to set get_pendown_state as you early said. Really
> *thanks* for your drive :)

No, with my patch, you don't need the get_pendown_state() and
you don't need to change the board-omap3evm.c ADS7846 related code.
So, I'm going to submit my patch properly.

> 
> Regards,
> Zumeng
>> -- Regards, Igor.
>> ads7846.patch
>>
>>
>> diff --git a/arch/arm/mach-omap2/common-board-devices.c b/arch/arm/mach-omap2/common-board-devices.c
>> index 1706ebc..c187586 100644
>> --- a/arch/arm/mach-omap2/common-board-devices.c
>> +++ b/arch/arm/mach-omap2/common-board-devices.c
>> @@ -63,28 +63,30 @@ void __init omap_ads7846_init(int bus_num, int gpio_pendown, int gpio_debounce,
>>  	struct spi_board_info *spi_bi = &ads7846_spi_board_info;
>>  	int err;
>>  
>> -	if (board_pdata && board_pdata->get_pendown_state) {
>> -		err = gpio_request_one(gpio_pendown, GPIOF_IN, "TSPenDown");
>> -		if (err) {
>> -			pr_err("Couldn't obtain gpio for TSPenDown: %d\n", err);
>> -			return;
>> -		}
>> -		gpio_export(gpio_pendown, 0);
>> -
>> -		if (gpio_debounce)
>> -			gpio_set_debounce(gpio_pendown, gpio_debounce);
>> +	err = gpio_request_one(gpio_pendown, GPIOF_IN, "TSPenDown");
>> +	if (err) {
>> +		pr_err("Couldn't obtain gpio for TSPenDown: %d\n", err);
>> +		return;
>>  	}
>>  	
>> +	if (gpio_debounce)
>> +		gpio_set_debounce(gpio_pendown, gpio_debounce);
>> +
>>  	spi_bi->bus_num	= bus_num;
>>  	spi_bi->irq	= gpio_to_irq(gpio_pendown);
>>  
>>  	if (board_pdata) {
>>  		board_pdata->gpio_pendown = gpio_pendown;
>>  		spi_bi->platform_data = board_pdata;
>> +		if (board_pdata->get_pendown_state)
>> +			gpio_export(gpio_pendown, 0);
>>  	} else {
>>  		ads7846_config.gpio_pendown = gpio_pendown;
>>  	}
>>  
>> +	if (!board_pdata || (board_pdata && !board_pdata->get_pendown_state))
>> +		gpio_free(gpio_pendown);
>> +
>>  	spi_register_board_info(&ads7846_spi_board_info, 1);
>>  }
>>  #else
> 

-- 
Regards,
Igor.