[PATCH v6 22/25] gpio/omap: save and restore debounce registers

[DebBarma, Tarun Kanti]

On Wed, Sep 7, 2011 at 5:33 AM, Kevin Hilman <khilman at ti.com> wrote:
> 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.)
Yes, it should haven been "Nishanth".

>
>> 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.
Good catch! Thanks.
--
Tarun
>
>> +     }
>> +
>> +     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
>