[PATCH v9 20/25] gpio/omap: fix incorrect access of debounce module

From: Tarun Kanti DebBarma
Date: Thu Feb 02 2012 - 12:32:47 EST


Enable debounce clock before writing/reading debounce registers.
Disable the clock at the end so that it is synchronized with the
pm_runtime_get/put_sync calls.

Enable debounce clock per module. This call is mandatory because
in omap_gpio_request() when *_runtime_get_sync() is called,
_gpio_dbck_enable() within runtime callbck fails to turn on dbck
because dbck_enable_mask used within _gpio_dbck_enable() is still
not initialized at that point. Therefore we have to enable dbck here.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@xxxxxx>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
---
drivers/gpio/gpio-omap.c | 18 +++++++++++++-----
1 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 0ea3dc9..7515382 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -203,22 +203,30 @@ static void _set_gpio_debounce(struct gpio_bank *bank, unsigned gpio,

l = GPIO_BIT(bank, gpio);

+ clk_enable(bank->dbck);
reg = bank->base + bank->regs->debounce;
__raw_writel(debounce, reg);

reg = bank->base + bank->regs->debounce_en;
val = __raw_readl(reg);

- if (debounce) {
+ if (debounce)
val |= l;
- clk_enable(bank->dbck);
- } else {
+ else
val &= ~l;
- clk_disable(bank->dbck);
- }
bank->dbck_enable_mask = val;

__raw_writel(val, reg);
+ clk_disable(bank->dbck);
+ /*
+ * Enable debounce clock per module.
+ * This call is mandatory because in omap_gpio_request() when
+ * *_runtime_get_sync() is called, _gpio_dbck_enable() within
+ * runtime callbck fails to turn on dbck because dbck_enable_mask
+ * used within _gpio_dbck_enable() is still not initialized at
+ * that point. Therefore we have to enable dbck here.
+ */
+ _gpio_dbck_enable(bank);
}

static inline void set_gpio_trigger(struct gpio_bank *bank, int gpio,
--
1.7.0.4

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