From: grinberg@compulab.co.il (Igor Grinberg)
Date: Wed, 13 Jun 2012 13:13:32 +0300
Subject: [PATCH V2 5/5] Input: ads7846: set proper debounce time in driver
 level
In-Reply-To: <4FD8577B.1010408@windriver.com>
References: <zumeng.chen@gmail.com>
 <1339551850-20827-1-git-send-email-zumeng.chen@gmail.com>
 <1339551850-20827-6-git-send-email-zumeng.chen@gmail.com>
 <4FD8467E.4010302@compulab.co.il> <4FD8577B.1010408@windriver.com>
Message-ID: <4FD867CC.30302@compulab.co.il>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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<zumeng.chen@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@windriver.com>
>>> Signed-off-by: Syed Mohammed Khasim<khasim@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
>> 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");
> 
> -- 
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Regards,
Igor.