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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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