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Subject[PATCH v9 18/25] gpio/omap: cleanup prepare_for_idle and resume_after_idle
Date
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>
---
drivers/gpio/gpio-omap.c | 241 +++++++++++++++++++++++++++-------------------
1 files changed, 143 insertions(+), 98 deletions(-)
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 9db892c..8b619fd 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);
@@ -1129,135 +1135,170 @@ 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;
-
- 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;
+}
+
+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);
}
}

@@ -1305,10 +1346,14 @@ 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


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