linux-kernel - [PATCH v9 19/25] gpio/omap: fix debounce clock handling

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Date:	Thu, 2 Feb 2012 23:00:45 +0530
From:	Tarun Kanti DebBarma <tarun.kanti@...com>
To:	<linux-omap@...r.kernel.org>
CC:	<grant.likely@...retlab.ca>, <khilman@...com>, <tony@...mide.com>,
	<linux-kernel@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	Tarun Kanti DebBarma <tarun.kanti@...com>
Subject: [PATCH v9 19/25] gpio/omap: fix debounce clock handling

The dbck_enable_mask indicates which all GPIOs within a bank have debounce
enabled and dbck is enabled/disabled based upon this. But there is no
mechanism to track the dbck state. In order to manage the dbck state we need
additional flag and logic so that turning off/on dbck is synchronized with
pm_runtime_put/get_sync calls.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@...com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@...com>
---
 drivers/gpio/gpio-omap.c |   29 +++++++++++++++++++----------
 1 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 8b619fd..0ea3dc9 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -67,6 +67,7 @@ struct gpio_bank {
 	struct clk *dbck;
 	u32 mod_usage;
 	u32 dbck_enable_mask;
+	bool dbck_enabled;
 	struct device *dev;
 	bool is_mpuio;
 	bool dbck_flag;
@@ -158,6 +159,22 @@ static inline void _gpio_rmw(void __iomem *base, u32 reg, u32 mask, bool set)
 	__raw_writel(l, base + reg);
 }
 
+static inline void _gpio_dbck_enable(struct gpio_bank *bank)
+{
+	if (bank->dbck_enable_mask && !bank->dbck_enabled) {
+		clk_enable(bank->dbck);
+		bank->dbck_enabled = true;
+	}
+}
+
+static inline void _gpio_dbck_disable(struct gpio_bank *bank)
+{
+	if (bank->dbck_enable_mask && bank->dbck_enabled) {
+		clk_disable(bank->dbck);
+		bank->dbck_enabled = false;
+	}
+}
+
 /**
  * _set_gpio_debounce - low level gpio debounce time
  * @bank: the gpio bank we're acting upon
@@ -1176,6 +1193,7 @@ save_gpio_context:
 				bank->get_context_loss_count(bank->dev);
 
 	omap_gpio_save_context(bank);
+	_gpio_dbck_disable(bank);
 	spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
@@ -1190,6 +1208,7 @@ static int omap_gpio_runtime_resume(struct device *dev)
 	unsigned long flags;
 
 	spin_lock_irqsave(&bank->lock, flags);
+	_gpio_dbck_enable(bank);
 	if (!bank->enabled_non_wakeup_gpios || !bank->workaround_enabled) {
 		spin_unlock_irqrestore(&bank->lock, flags);
 		return 0;
@@ -1271,16 +1290,11 @@ void omap2_gpio_prepare_for_idle(int pwr_mode)
 	struct gpio_bank *bank;
 
 	list_for_each_entry(bank, &omap_gpio_list, node) {
-		int j;
-
 		if (!bank->mod_usage || !bank->loses_context)
 			continue;
 
 		bank->power_mode = pwr_mode;
 
-		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
-			clk_disable(bank->dbck);
-
 		pm_runtime_put_sync_suspend(bank->dev);
 	}
 }
@@ -1290,14 +1304,9 @@ void omap2_gpio_resume_after_idle(void)
 	struct gpio_bank *bank;
 
 	list_for_each_entry(bank, &omap_gpio_list, node) {
-		int j;
-
 		if (!bank->mod_usage || !bank->loses_context)
 			continue;
 
-		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
-			clk_enable(bank->dbck);
-
 		pm_runtime_get_sync(bank->dev);
 	}
 }
-- 
1.7.0.4

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