Subject: [PATCH] Revert "ARM: OMAP3530evm: set pendown_state and debounce time for ads7846"

From: [email-masked] (Igor Grinberg)
Date: Tue, 07 Aug 2012 09:05:08 +0300

On 08/07/12 04:42, Zumeng Chen wrote:
> ? 2012?08?07? 04:22, Igor Grinberg ??:
>> 1) The above commit introduced a common ->get_pendown_state() function
>> into the generic code, but that function was board-specific for the
>> OMAP3EVM and thus broke most other boards using this code.
>>
>> 2) The above commit was mis-merged introducing another bug which
>> prevents the ads7846 driver probe function to succeed.
>> The omap_ads7846_init() function frees the pendown GPIO in case there is
>> no ->get_pendown_state() function set by the caller (board specific
>> code), so it can be requested later by the ads7846 driver.
>> The above commit add a common ->get_pendown_state() function without
>> removing the gpio_free() call and thus once the ads7846 driver tries
>> to use the pendown GPIO, it crashes as the pendown GPIO has not been
>> requested.
>>
>> 3) The above commit introduces NO new functionality as
>> get_pendown_state() function is already implemented in a suitable way by
>> the ads7846 driver and the debounce time handling has already been
>> fixed by commit 97ee9f01 (ARM: OMAP: fix the ads7846 init code).
> Igor,
> 
> I suspect these two patches(this and 97ee9f01) works well, and there
> is something new introduced in ads7846.c, I'll try to look at that new
> stuff in this weekend.
> 
> Please refer to in-line comments:
> 
> Regards,
> Zumeng
>>
>> This reverts commit 16aced80f6739beb2a6ff7b6f96c83ba80d331e8.
>>
>> Conflicts:
>> 	arch/arm/mach-omap2/common-board-devices.c
>>
>> Solved by taking the working version prior to the above commit.
>>
>> Cc: Zumeng Chen <[email-masked]>
>> Cc: Arnd Bergmann <[email-masked]>
>> Signed-off-by: Igor Grinberg <[email-masked]>
>> ---
>> Kevin, sorry for the late reply.
>> How about the above commit message and the below patch?
>>
>> The patch applies cleanly to Tony's master branch (6 Aug 2012)
>> or Kevin's kevin-omap-pm/for_3.6/fixes/ads7846
>> after resetting two top most commits.
>>
>> This patch has been tested on both above branches on cm-t3730.
>> Any other board tested will be greately appreciated.
>>
>> Also, if after all said in the commit message, you still don't
>> want to revert the original patch, feel free to post your thoughts.
>>
>>  arch/arm/mach-omap2/board-omap3evm.c       |    1 +
>>  arch/arm/mach-omap2/common-board-devices.c |   11 -----------
>>  arch/arm/mach-omap2/common-board-devices.h |    1 -
>>  3 files changed, 1 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/board-omap3evm.c b/arch/arm/mach-omap2/board-omap3evm.c
>> index ef230a0..0d362e9 100644
>> --- a/arch/arm/mach-omap2/board-omap3evm.c
>> +++ b/arch/arm/mach-omap2/board-omap3evm.c
>> @@ -58,6 +58,7 @@
>>  #include "hsmmc.h"
>>  #include "common-board-devices.h"
>>  
>> +#define OMAP3_EVM_TS_GPIO	175
>>  #define OMAP3_EVM_EHCI_VBUS	22
>>  #define OMAP3_EVM_EHCI_SELECT	61
>>  
>> diff --git a/arch/arm/mach-omap2/common-board-devices.c b/arch/arm/mach-omap2/common-board-devices.c
>> index 1473474..c187586 100644
>> --- a/arch/arm/mach-omap2/common-board-devices.c
>> +++ b/arch/arm/mach-omap2/common-board-devices.c
>> @@ -35,16 +35,6 @@ static struct omap2_mcspi_device_config ads7846_mcspi_config = {
>>  	.turbo_mode	= 0,
>>  };
>>  
>> -/*
>> - * ADS7846 driver maybe request a gpio according to the value
>> - * of pdata->get_pendown_state, but we have done this. So set
>> - * get_pendown_state to avoid twice gpio requesting.
>> - */
>> -static int omap3_get_pendown_state(void)
>> -{
>> -	return !gpio_get_value(OMAP3_EVM_TS_GPIO);
>> -}
>> -
>>  static struct ads7846_platform_data ads7846_config = {
>>  	.x_max			= 0x0fff,
>>  	.y_max			= 0x0fff,
>> @@ -55,7 +45,6 @@ static struct ads7846_platform_data ads7846_config = {
>>  	.debounce_rep		= 1,
>>  	.gpio_pendown		= -EINVAL,
>>  	.keep_vref_on		= 1,
>> -	.get_pendown_state	= &omap3_get_pendown_state,
> You remove this, then please look at the following codes:
> 
> drivers/input/touchscreen/ads7846.c
> 
> 969 if (pdata->get_pendown_state) {
> 970 ts->get_pendown_state = pdata->get_pendown_state;
> 971 } else if (gpio_is_valid(pdata->gpio_pendown)) {
> 972
> 973 err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
> ^^^, the driver will want to request again, then it should
> be error if i'm right.

This patch removes the get_pendown_state function pointer from
the ads7846_platform_data and gpio_free() fires as there is no
get_pendown_state and therefore there will be no problem to request
it again by the ads7846 driver.
So, no there will be no error and if you still doubt, please test.

> 
> 974 "ads7846_pendown");
> 975 if (err) {
> 976 dev_err(&spi->dev,
> 977 "failed to request/setup pendown GPIO%d: %d\n",
> 978 pdata->gpio_pendown, err);
> 979 return err;
> 980 }
> 981
> 982 ts->gpio_pendown = pdata->gpio_pendown;
> 983
> 984 } else {

[...]

-- 
Regards,
Igor.