[PATCH v9 18/31] gpio/omap: cleanup prepare_for_idle and resume_after_idle

[Tarun Kanti DebBarma <tarun.kanti@ti.com>]

Since *_prepare_for_idle() and *_resume_after_idle() are called
with interrupts disabled they should be kept as simple as possible.
So, moving most of the stuff to *_runtime_suspend/resume() callbacks.

To avoid invalid context restore happening in *_runtime_resume()
callback as a result of *_get_sync() call in *_gpio_probe(), update
bank->context_loss_count. This would make context restore condition
check false in the callback and skip restore until further
initialization take place.

Unlike most GPIO registers the OE has 0xffffffff as the default value.
To make sure invalid context is not restored, updating the OE context
with default value.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Signed-off-by: Charulatha V <charu@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
 drivers/gpio/gpio-omap.c |  249 +++++++++++++++++++++++++++-------------------
 1 files changed, 147 insertions(+), 102 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 174aa06..175a364 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -29,6 +29,8 @@
 #include <asm/gpio.h>
 #include <asm/mach/irq.h>
 
+#define OFF_MODE	1
+
 static LIST_HEAD(omap_gpio_list);
 
 struct gpio_regs {
@@ -74,6 +76,7 @@ struct gpio_bank {
 	u32 context_loss_count;
 	bool need_context_restore;
 	u16 id;
+	int power_mode;
 
 	void (*set_dataout)(struct gpio_bank *bank, int gpio, int enable);
 	u32 (*get_context_loss_count)(struct device *dev);
@@ -908,6 +911,8 @@ static void omap_gpio_mod_init(struct gpio_bank *bank)
 	if (bank->regs->debounce_en)
 		_gpio_rmw(base, bank->regs->debounce_en, 0, 1);
 
+	/* Save OE default value (0xffffffff) in the context */
+	bank->context.oe = __raw_readl(bank->base + bank->regs->direction);
 	 /* Initialize interface clk ungated, module enabled */
 	if (bank->regs->ctrl)
 		_gpio_rmw(base, bank->regs->ctrl, 0, 1);
@@ -1059,6 +1064,13 @@ static int __devinit omap_gpio_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(bank->dev);
 	pm_runtime_irq_safe(bank->dev);
+	/*
+	 * Avoid context restore happening in runtime callback
+	 * because of pm_runtime_get_sync() by making context
+	 * context restore condition check false. This is to make
+	 * sure that we do not restore invalid context.
+	 */
+	bank->context_loss_count = bank->get_context_loss_count(bank->dev);
 	pm_runtime_get_sync(bank->dev);
 
 	if (bank->is_mpuio)
@@ -1132,141 +1144,170 @@ static int omap_gpio_resume(struct device *dev)
 static void omap_gpio_save_context(struct gpio_bank *bank);
 static void omap_gpio_restore_context(struct gpio_bank *bank);
 
-void omap2_gpio_prepare_for_idle(int off_mode)
+static int omap_gpio_runtime_suspend(struct device *dev)
 {
-	struct gpio_bank *bank;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct gpio_bank *bank = platform_get_drvdata(pdev);
+	u32 l1 = 0, l2 = 0;
+	unsigned long flags;
 
-	list_for_each_entry(bank, &omap_gpio_list, node) {
-		u32 l1 = 0, l2 = 0;
-		int j;
+	if (!bank->loses_context)
+		return 0;
 
-		if (!bank->loses_context)
-			continue;
+	spin_lock_irqsave(&bank->lock, flags);
+	if (bank->power_mode != OFF_MODE) {
+		bank->power_mode = 0;
+		goto save_gpio_context;
+	}
+	/*
+	 * If going to OFF, remove triggering for all
+	 * non-wakeup GPIOs.  Otherwise spurious IRQs will be
+	 * generated.  See OMAP2420 Errata item 1.101.
+	 */
+	if (!(bank->enabled_non_wakeup_gpios))
+		goto save_gpio_context;
 
-		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
-			clk_disable(bank->dbck);
+	bank->saved_datain = __raw_readl(bank->base +
+						bank->regs->datain);
+	l1 = __raw_readl(bank->base + bank->regs->fallingdetect);
+	l2 = __raw_readl(bank->base + bank->regs->risingdetect);
 
-		if (!off_mode)
-			continue;
+	bank->saved_fallingdetect = l1;
+	bank->saved_risingdetect = l2;
+	l1 &= ~bank->enabled_non_wakeup_gpios;
+	l2 &= ~bank->enabled_non_wakeup_gpios;
 
-		/* If going to OFF, remove triggering for all
-		 * non-wakeup GPIOs.  Otherwise spurious IRQs will be
-		 * generated.  See OMAP2420 Errata item 1.101. */
-		if (!(bank->enabled_non_wakeup_gpios))
-			goto save_gpio_context;
+	__raw_writel(l1, bank->base + bank->regs->fallingdetect);
+	__raw_writel(l2, bank->base + bank->regs->risingdetect);
 
-		bank->saved_datain = __raw_readl(bank->base +
-							bank->regs->datain);
-		l1 = __raw_readl(bank->base + bank->regs->fallingdetect);
-		l2 = __raw_readl(bank->base + bank->regs->risingdetect);
+	bank->need_context_restore = true;
 
-		bank->saved_fallingdetect = l1;
-		bank->saved_risingdetect = l2;
-		l1 &= ~bank->enabled_non_wakeup_gpios;
-		l2 &= ~bank->enabled_non_wakeup_gpios;
+save_gpio_context:
+	if (bank->get_context_loss_count)
+		bank->context_loss_count =
+				bank->get_context_loss_count(bank->dev);
 
-		__raw_writel(l1, bank->base + bank->regs->fallingdetect);
-		__raw_writel(l2, bank->base + bank->regs->risingdetect);
+	omap_gpio_save_context(bank);
+	spin_unlock_irqrestore(&bank->lock, flags);
 
-		bank->need_context_restore = true;
+	return 0;
+}
 
-save_gpio_context:
+static int omap_gpio_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct gpio_bank *bank = platform_get_drvdata(pdev);
+	u32 context_lost_cnt_after;
+	u32 l = 0, gen, gen0, gen1;
+	unsigned long flags;
 
-		if (bank->get_context_loss_count)
-			bank->context_loss_count =
-				bank->get_context_loss_count(bank->dev);
+	if (!bank->loses_context)
+		return 0;
 
-		omap_gpio_save_context(bank);
+	spin_lock_irqsave(&bank->lock, flags);
+	if (!bank->enabled_non_wakeup_gpios || !bank->need_context_restore) {
+		spin_unlock_irqrestore(&bank->lock, flags);
+		return 0;
+	}
 
-		if (!pm_runtime_suspended(bank->dev))
-			pm_runtime_put(bank->dev);
+	if (bank->get_context_loss_count) {
+		context_lost_cnt_after =
+			bank->get_context_loss_count(bank->dev);
+		if (context_lost_cnt_after != bank->context_loss_count) {
+			omap_gpio_restore_context(bank);
+		} else {
+			spin_unlock_irqrestore(&bank->lock, flags);
+			return 0;
+		}
 	}
-}
 
-void omap2_gpio_resume_after_idle(void)
-{
-	struct gpio_bank *bank;
+	__raw_writel(bank->saved_fallingdetect,
+			bank->base + bank->regs->fallingdetect);
+	__raw_writel(bank->saved_risingdetect,
+			bank->base + bank->regs->risingdetect);
+	l = __raw_readl(bank->base + bank->regs->datain);
 
-	list_for_each_entry(bank, &omap_gpio_list, node) {
-		u32 context_lost_cnt_after;
-		u32 l = 0, gen, gen0, gen1;
-		int j;
+	/*
+	 * Check if any of the non-wakeup interrupt GPIOs have changed
+	 * state.  If so, generate an IRQ by software.  This is
+	 * horribly racy, but it's the best we can do to work around
+	 * this silicon bug.
+	 */
+	l ^= bank->saved_datain;
+	l &= bank->enabled_non_wakeup_gpios;
 
-		if (!bank->loses_context)
-			continue;
+	/*
+	 * No need to generate IRQs for the rising edge for gpio IRQs
+	 * configured with falling edge only; and vice versa.
+	 */
+	gen0 = l & bank->saved_fallingdetect;
+	gen0 &= bank->saved_datain;
+	gen1 = l & bank->saved_risingdetect;
+	gen1 &= ~(bank->saved_datain);
 
-		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
-			clk_enable(bank->dbck);
+	/* FIXME: Consider GPIO IRQs with level detections properly! */
+	gen = l & (~(bank->saved_fallingdetect) & ~(bank->saved_risingdetect));
+	/* Consider all GPIO IRQs needed to be updated */
+	gen |= gen0 | gen1;
 
-		if (!bank->need_context_restore)
-			continue;
+	if (gen) {
+		u32 old0, old1;
 
-		bank->need_context_restore = false;
-		if (pm_runtime_suspended(bank->dev))
-			pm_runtime_get_sync(bank->dev);
+		old0 = __raw_readl(bank->base + bank->regs->leveldetect0);
+		old1 = __raw_readl(bank->base + bank->regs->leveldetect1);
 
-		if (bank->get_context_loss_count) {
-			context_lost_cnt_after =
-				bank->get_context_loss_count(bank->dev);
-			if (context_lost_cnt_after != bank->context_loss_count
-				|| !context_lost_cnt_after)
-				omap_gpio_restore_context(bank);
+		if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
+			__raw_writel(old0 | gen, bank->base +
+						bank->regs->leveldetect0);
+			__raw_writel(old1 | gen, bank->base +
+						bank->regs->leveldetect1);
 		}
 
-		if (!(bank->enabled_non_wakeup_gpios))
-			continue;
+		if (cpu_is_omap44xx()) {
+			__raw_writel(old0 | l, bank->base +
+						bank->regs->leveldetect0);
+			__raw_writel(old1 | l, bank->base +
+						bank->regs->leveldetect1);
+		}
+		__raw_writel(old0, bank->base + bank->regs->leveldetect0);
+		__raw_writel(old1, bank->base + bank->regs->leveldetect1);
+	}
 
-		__raw_writel(bank->saved_fallingdetect,
-				bank->base + bank->regs->fallingdetect);
-		__raw_writel(bank->saved_risingdetect,
-				bank->base + bank->regs->risingdetect);
-		l = __raw_readl(bank->base + bank->regs->datain);
+	bank->need_context_restore = false;
+	spin_unlock_irqrestore(&bank->lock, flags);
 
-		/* Check if any of the non-wakeup interrupt GPIOs have changed
-		 * state.  If so, generate an IRQ by software.  This is
-		 * horribly racy, but it's the best we can do to work around
-		 * this silicon bug. */
-		l ^= bank->saved_datain;
-		l &= bank->enabled_non_wakeup_gpios;
+	return 0;
+}
 
-		/*
-		 * No need to generate IRQs for the rising edge for gpio IRQs
-		 * configured with falling edge only; and vice versa.
-		 */
-		gen0 = l & bank->saved_fallingdetect;
-		gen0 &= bank->saved_datain;
+void omap2_gpio_prepare_for_idle(int power_mode)
+{
+	struct gpio_bank *bank;
 
-		gen1 = l & bank->saved_risingdetect;
-		gen1 &= ~(bank->saved_datain);
+	list_for_each_entry(bank, &omap_gpio_list, node) {
+		int j;
 
-		/* FIXME: Consider GPIO IRQs with level detections properly! */
-		gen = l & (~(bank->saved_fallingdetect) &
-				~(bank->saved_risingdetect));
-		/* Consider all GPIO IRQs needed to be updated */
-		gen |= gen0 | gen1;
+		if (!bank->mod_usage)
+			continue;
 
-		if (gen) {
-			u32 old0, old1;
+		bank->power_mode = power_mode;
 
-			old0 = __raw_readl(bank->base +
-						bank->regs->leveldetect0);
-			old1 = __raw_readl(bank->base +
-						bank->regs->leveldetect1);
+		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
+			clk_disable(bank->dbck);
+	}
+}
+
+void omap2_gpio_resume_after_idle(void)
+{
+	struct gpio_bank *bank;
 
-			if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
-				old0 |= gen;
-				old1 |= gen;
-			}
+	list_for_each_entry(bank, &omap_gpio_list, node) {
+		int j;
 
-			if (cpu_is_omap44xx()) {
-				old0 |= l;
-				old1 |= l;
-			}
-			__raw_writel(old0, bank->base +
-						bank->regs->leveldetect0);
-			__raw_writel(old1, bank->base +
-						bank->regs->leveldetect1);
-		}
+		if (!bank->mod_usage)
+			continue;
+
+		for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
+			clk_enable(bank->dbck);
 	}
 }
 
@@ -1314,10 +1355,14 @@ static void omap_gpio_restore_context(struct gpio_bank *bank)
 #else
 #define omap_gpio_suspend NULL
 #define omap_gpio_resume NULL
+#define omap_gpio_runtime_suspend NULL
+#define omap_gpio_runtime_resume NULL
 #endif
 
 static const struct dev_pm_ops gpio_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(omap_gpio_suspend, omap_gpio_resume)
+	SET_RUNTIME_PM_OPS(omap_gpio_runtime_suspend, omap_gpio_runtime_resume,
+									NULL)
 };
 
 static struct platform_driver omap_gpio_driver = {
-- 
1.7.0.4