gpio/omap: cleanup prepare_for_idle and resume_after_idle

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. The workaround_enabled static variable
is now a member of struct gpio_bank.

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>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 147 insertions, 98 deletions

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index e9a30fa8715b..d483cc9f0c63 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 {
@@ -73,6 +75,8 @@ struct gpio_bank {
         u32 width;
         int context_loss_count;
         u16 id;
+        int power_mode;
+        bool workaround_enabled;
 
         void (*set_dataout)(struct gpio_bank *bank, int gpio, int enable);
         int (*get_context_loss_count)(struct device *dev);
@@ -905,6 +909,8 @@ 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);
@@ -1127,141 +1133,179 @@ static int omap_gpio_resume(struct device *dev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
+#if defined(CONFIG_PM_RUNTIME)
 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;
-
-        list_for_each_entry(bank, &omap_gpio_list, node) {
-                u32 l1 = 0, l2 = 0;
-                int j;
-
-                if (!bank->loses_context)
-                        continue;
-
-                for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
-                        clk_disable(bank->dbck);
+        struct platform_device *pdev = to_platform_device(dev);
+        struct gpio_bank *bank = platform_get_drvdata(pdev);
+        u32 l1 = 0, l2 = 0;
+        unsigned long flags;
 
-                if (!off_mode)
-                        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;
 
-                /* 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;
+        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->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->saved_fallingdetect = l1;
+        bank->saved_risingdetect = l2;
+        l1 &= ~bank->enabled_non_wakeup_gpios;
+        l2 &= ~bank->enabled_non_wakeup_gpios;
 
-                bank->saved_fallingdetect = l1;
-                bank->saved_risingdetect = l2;
-                l1 &= ~bank->enabled_non_wakeup_gpios;
-                l2 &= ~bank->enabled_non_wakeup_gpios;
+        __raw_writel(l1, bank->base + bank->regs->fallingdetect);
+        __raw_writel(l2, bank->base + bank->regs->risingdetect);
 
-                __raw_writel(l1, bank->base + bank->regs->fallingdetect);
-                __raw_writel(l2, bank->base + bank->regs->risingdetect);
+        bank->workaround_enabled = true;
 
 save_gpio_context:
-
-                if (bank->get_context_loss_count)
-                        bank->context_loss_count =
+        if (bank->get_context_loss_count)
+                bank->context_loss_count =
                                 bank->get_context_loss_count(bank->dev);
 
-                omap_gpio_save_context(bank);
+        omap_gpio_save_context(bank);
+        spin_unlock_irqrestore(&bank->lock, flags);
 
-                if (!pm_runtime_suspended(bank->dev))
-                        pm_runtime_put(bank->dev);
-        }
+        return 0;
 }
 
-void omap2_gpio_resume_after_idle(void)
+static int omap_gpio_runtime_resume(struct device *dev)
 {
-        struct gpio_bank *bank;
-
-        list_for_each_entry(bank, &omap_gpio_list, node) {
-                int context_lost_cnt_after;
-                u32 l = 0, gen, gen0, gen1;
-                int j;
-
-                if (!bank->loses_context)
-                        continue;
-
-                for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
-                        clk_enable(bank->dbck);
+        struct platform_device *pdev = to_platform_device(dev);
+        struct gpio_bank *bank = platform_get_drvdata(pdev);
+        int context_lost_cnt_after;
+        u32 l = 0, gen, gen0, gen1;
+        unsigned long flags;
 
-                if (pm_runtime_suspended(bank->dev))
-                        pm_runtime_get_sync(bank->dev);
+        spin_lock_irqsave(&bank->lock, flags);
+        if (!bank->enabled_non_wakeup_gpios || !bank->workaround_enabled) {
+                spin_unlock_irqrestore(&bank->lock, flags);
+                return 0;
+        }
 
-                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 (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);
+                } else {
+                        spin_unlock_irqrestore(&bank->lock, flags);
+                        return 0;
                 }
+        }
 
-                if (!(bank->enabled_non_wakeup_gpios))
-                        continue;
+        __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);
 
-                __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);
+        /*
+         * 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;
 
-                /* 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;
+        /*
+         * 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;
 
-                /*
-                 * 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);
 
-                gen1 = l & bank->saved_risingdetect;
-                gen1 &= ~(bank->saved_datain);
+        /* 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;
 
-                /* 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 (gen) {
+                u32 old0, old1;
 
-                if (gen) {
-                        u32 old0, old1;
+                old0 = __raw_readl(bank->base + bank->regs->leveldetect0);
+                old1 = __raw_readl(bank->base + bank->regs->leveldetect1);
 
-                        old0 = __raw_readl(bank->base +
+                if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
+                        __raw_writel(old0 | gen, bank->base +
                                                 bank->regs->leveldetect0);
-                        old1 = __raw_readl(bank->base +
+                        __raw_writel(old1 | gen, bank->base +
                                                 bank->regs->leveldetect1);
+                }
 
-                        if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
-                                old0 |= gen;
-                                old1 |= gen;
-                        }
-
-                        if (cpu_is_omap44xx()) {
-                                old0 |= l;
-                                old1 |= l;
-                        }
-                        __raw_writel(old0, bank->base +
+                if (cpu_is_omap44xx()) {
+                        __raw_writel(old0 | l, bank->base +
                                                 bank->regs->leveldetect0);
-                        __raw_writel(old1, bank->base +
+                        __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);
+        }
+
+        bank->workaround_enabled = false;
+        spin_unlock_irqrestore(&bank->lock, flags);
+
+        return 0;
+}
+#endif /* CONFIG_PM_RUNTIME */
+
+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);
+        }
+}
+
+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);
         }
 }
 
+#if defined(CONFIG_PM_RUNTIME)
 static void omap_gpio_save_context(struct gpio_bank *bank)
 {
         bank->context.irqenable1 =
@@ -1303,13 +1347,18 @@ static void omap_gpio_restore_context(struct gpio_bank *bank)
                                 bank->base + bank->regs->fallingdetect);
         __raw_writel(bank->context.dataout, bank->base + bank->regs->dataout);
 }
+#endif /* CONFIG_PM_RUNTIME */
 #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 = {