[PATCH v6 22/25] gpio/omap: save and restore debounce registers
Kevin Hilman
khilman at ti.com
Tue Sep 6 20:03:10 EDT 2011
Tarun Kanti DebBarma <tarun.kanti at ti.com> writes:
> From: Nishant Menon <nm at ti.com>
Check spelling of first name (I believe version in signed-off-by below
is the correct one.)
> GPIO debounce registers need to be saved and restored for proper functioning
> of driver. To save the registers, we cannot cut the clock before the save,
> hence move the clk disable after the save.
>
> Signed-off-by: Nishanth Menon <nm at ti.com>
> Signed-off-by: Tarun Kanti DebBarma <tarun.kanti at ti.com>
> Reviewed-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
> ---
> drivers/gpio/gpio-omap.c | 22 +++++++++++++++++++---
> 1 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index dc382f6..67e08e9 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -41,6 +41,8 @@ struct gpio_regs {
> u32 risingdetect;
> u32 fallingdetect;
> u32 dataout;
> + u32 debounce;
> + u32 debounce_en;
> };
>
> struct gpio_bank {
> @@ -1158,9 +1160,6 @@ static int omap_gpio_runtime_suspend(struct device *dev)
> u32 l1 = 0, l2 = 0;
> int j;
>
> - for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
> - clk_disable(bank->dbck);
> -
> if (!bank->mod_usage)
> return 0;
>
> @@ -1192,6 +1191,16 @@ update_gpio_context_count:
> bank->context_loss_count =
> bank->get_context_loss_count(bank->dev);
>
> + if (bank->dbck_enable_mask) {
> + bank->context.debounce = __raw_readl(bank->base +
> + bank->regs->debounce);
> + bank->context.debounce_en = __raw_readl(bank->base +
> + bank->regs->debounce_en);
Here you're taking a step backwards from the goal of not having to read
registers in the runtime suspend callback.
Rather than reading the registers here, the values should be saved into
bank->context when they are initially written (_set_gpio_debounce()), so
you don't have the overhead of reading the registers in ->runtime_suspend.
> + }
> +
> + for (j = 0; j < hweight_long(bank->dbck_enable_mask); j++)
> + clk_disable(bank->dbck);
> +
> return 0;
> }
>
> @@ -1331,6 +1340,13 @@ static void omap_gpio_restore_context(struct gpio_bank *bank)
> __raw_writel(bank->context.fallingdetect,
> bank->base + bank->regs->fallingdetect);
> __raw_writel(bank->context.dataout, bank->base + bank->regs->dataout);
> +
> + if (bank->dbck_enable_mask) {
> + __raw_writel(bank->context.debounce, bank->base +
> + bank->regs->debounce);
> + __raw_writel(bank->context.debounce_en,
> + bank->base + bank->regs->debounce_en);
> + }
> }
> #else
> #define omap_gpio_runtime_suspend NULL
Kevin
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