[PATCH] ARM: OMAP2+: ads7846 init: fix fault caused by freeing pen-down GPIO

[zumeng.chen]

On 2012年07月27日 03:30, Kevin Hilman wrote:
> + Zumeng Chen
>
> Igor Grinberg<grinberg at compulab.co.il>  writes:
>
>> Hi Kevin,
>>
>> I've just noticed that the patch has been modified by Arnd in a way
>> that of course will trigger GPIO use without being requested.
>> I'm sorry, I was not available by that time Arnd changed the patch.
> Your right, your original patch isn't the problem.  I found the root
> cause.
>
> The real problem is actually introduced by the merge of your patch from
> the arm-soc/cleanup branch, and this one from Zumeng Chen: commit
> 16aced80f6 (ARM: OMAP3530evm: set pendown_state and debounce time for
> ads7846) from the arm-soc/boards branch.
>
> However, looking closer at the one from Zumeng, that one is clearly not
> right.  It unconditionally adds a *board-specific* ->get_pendown_state
> function to the pdata that is common to *all* boards.  That's just wrong
> and has the side-effect of making ->get_pendown_state() wrong on every
> board except the OMAP3EVM.  Oops.
>
> So, IMO, in addition to $SUBJECT patch, in order to get the touchscreen
> GPIO working on non OMAP3EVM boards, we also need something like this as
> well.
Definitely, thanks Kevin.
> Igor, Zumeng, could you try this out on your boards anc confirm if it's
> working?  I currently don't have a board setup with a touchscreen in my
> board farm.
Acked

Zumeng
> Kevin
>
>  From 85516c6a3354967caf4cff434d28c3001cd411eb Mon Sep 17 00:00:00 2001
> From: Kevin Hilman<khilman at ti.com>
> Date: Thu, 26 Jul 2012 12:15:38 -0700
> Subject: [PATCH 2/2] ARM: OMAP2+: ads7846: fix ->get_pendown_state() to work
>   on all boards
>
> commit 16aced80f6 (ARM: OMAP3530evm: set pendown_state and debounce
> time for ads7846) introduced a common ->get_pendown_state() function
> into the generic code, but that function was board-specific for the
> OMAP3EVM.
>
> Fix this up to work for all boards that pass in a pendown GPIO.
>
> Cc: Zumeng Chen<zumeng.chen at windriver.com>
> Cc: Igor Grinberg<grinberg at compulab.co.il>
> Signed-off-by: Kevin Hilman<khilman at ti.com>
> ---
>   arch/arm/mach-omap2/board-omap3evm.c       |    1 +
>   arch/arm/mach-omap2/common-board-devices.c |    4 +++-
>   arch/arm/mach-omap2/common-board-devices.h |    1 -
>   3 files changed, 4 insertions(+), 2 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 0fee95f..06f176f 100644
> --- a/arch/arm/mach-omap2/common-board-devices.c
> +++ b/arch/arm/mach-omap2/common-board-devices.c
> @@ -40,9 +40,10 @@ static struct omap2_mcspi_device_config ads7846_mcspi_config = {
>    * of pdata->get_pendown_state, but we have done this. So set
>    * get_pendown_state to avoid twice gpio requesting.
>    */
> +static int omap3_gpio_pendown;
>   static int omap3_get_pendown_state(void)
>   {
> -	return !gpio_get_value(OMAP3_EVM_TS_GPIO);
> +	return !gpio_get_value(omap3_gpio_pendown);
>   }
>
>   static struct ads7846_platform_data ads7846_config = {
> @@ -74,6 +75,7 @@ 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;
>
> +	omap3_gpio_pendown = gpio_pendown;
>   	err = gpio_request_one(gpio_pendown, GPIOF_IN, "TSPenDown");
>   	if (err) {
>   		pr_err("Couldn't obtain gpio for TSPenDown: %d\n", err);
> diff --git a/arch/arm/mach-omap2/common-board-devices.h b/arch/arm/mach-omap2/common-board-devices.h
> index 4c4ef6a..a0b4a428 100644
> --- a/arch/arm/mach-omap2/common-board-devices.h
> +++ b/arch/arm/mach-omap2/common-board-devices.h
> @@ -4,7 +4,6 @@
>   #include "twl-common.h"
>
>   #define NAND_BLOCK_SIZE	SZ_128K
> -#define OMAP3_EVM_TS_GPIO	175
>
>   struct mtd_partition;
>   struct ads7846_platform_data;