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>

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index e9a30fa8715b479051c1b4659ac0f8d1caaf8049..d483cc9f0c638e485476d54ec8c6c91481062014 100644 (file)
--- 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 = {