[PATCH] gpio: omap: implement get_direction

[PATCH] gpio: omap: implement get_direction

[yegorslists]

From: Yegor Yefremov <yegorslists@googlemail.com>

This patch implements gpio_chip's get_direction() routine, that
lets other drivers get particular GPIOs direction using
struct gpio_desc.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
---
 drivers/gpio/gpio-omap.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 19b886c..b55bf7b 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -102,6 +102,20 @@ static int omap_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 	return irq_find_mapping(bank->domain, offset);
 }
 
+static int _get_gpio_direction(struct gpio_bank *bank, int gpio)
+{
+	void __iomem *reg = bank->base;
+	u32 l;
+	u32 mask = 1 << gpio;
+
+	reg += bank->regs->direction;
+	l = readl_relaxed(reg);
+	if (l & mask)
+		return 1;
+
+	return 0;
+}
+
 static void _set_gpio_direction(struct gpio_bank *bank, int gpio, int is_input)
 {
 	void __iomem *reg = bank->base;
@@ -936,6 +950,19 @@ static inline void mpuio_init(struct gpio_bank *bank)
 
 /*---------------------------------------------------------------------*/
 
+static int gpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+	struct gpio_bank *bank;
+	unsigned long flags;
+	int dir;
+
+	bank = container_of(chip, struct gpio_bank, chip);
+	spin_lock_irqsave(&bank->lock, flags);
+	dir = _get_gpio_direction(bank, offset);
+	spin_unlock_irqrestore(&bank->lock, flags);
+	return dir;
+}
+
 static int gpio_input(struct gpio_chip *chip, unsigned offset)
 {
 	struct gpio_bank *bank;
@@ -1092,6 +1119,7 @@ static void omap_gpio_chip_init(struct gpio_bank *bank)
 	 */
 	bank->chip.request = omap_gpio_request;
 	bank->chip.free = omap_gpio_free;
+	bank->chip.get_direction = gpio_get_direction;
 	bank->chip.direction_input = gpio_input;
 	bank->chip.get = gpio_get;
 	bank->chip.direction_output = gpio_output;
-- 
1.7.7

Re: [PATCH] gpio: omap: implement get_direction

[Javier Martinez Canillas]

Hello Yegor,

On Tue, Apr 22, 2014 at 11:23 AM,  <yegorslists@googlemail.com> wrote:
> From: Yegor Yefremov <yegorslists@googlemail.com>
>
> This patch implements gpio_chip's get_direction() routine, that
> lets other drivers get particular GPIOs direction using
> struct gpio_desc.
>
> Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
> ---
>  drivers/gpio/gpio-omap.c |   28 ++++++++++++++++++++++++++++
>  1 files changed, 28 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index 19b886c..b55bf7b 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -102,6 +102,20 @@ static int omap_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
>         return irq_find_mapping(bank->domain, offset);
>  }
>
> +static int _get_gpio_direction(struct gpio_bank *bank, int gpio)
> +{
> +       void __iomem *reg = bank->base;
> +       u32 l;
> +       u32 mask = 1 << gpio;
> +
> +       reg += bank->regs->direction;
> +       l = readl_relaxed(reg);
> +       if (l & mask)
> +               return 1;
> +
> +       return 0;
> +}
> +

You can avoid the if condition here by using return !!(l & mask) but
the above code is more clear indeed so is up to you.

Acked-by: Javier Martinez Canillas <javier@dowhile0.org>

>  static void _set_gpio_direction(struct gpio_bank *bank, int gpio, int is_input)
>  {
>         void __iomem *reg = bank->base;
> @@ -936,6 +950,19 @@ static inline void mpuio_init(struct gpio_bank *bank)
>
>  /*---------------------------------------------------------------------*/
>
> +static int gpio_get_direction(struct gpio_chip *chip, unsigned offset)
> +{
> +       struct gpio_bank *bank;
> +       unsigned long flags;
> +       int dir;
> +
> +       bank = container_of(chip, struct gpio_bank, chip);
> +       spin_lock_irqsave(&bank->lock, flags);
> +       dir = _get_gpio_direction(bank, offset);
> +       spin_unlock_irqrestore(&bank->lock, flags);
> +       return dir;
> +}
> +
>  static int gpio_input(struct gpio_chip *chip, unsigned offset)
>  {
>         struct gpio_bank *bank;
> @@ -1092,6 +1119,7 @@ static void omap_gpio_chip_init(struct gpio_bank *bank)
>          */
>         bank->chip.request = omap_gpio_request;
>         bank->chip.free = omap_gpio_free;
> +       bank->chip.get_direction = gpio_get_direction;
>         bank->chip.direction_input = gpio_input;
>         bank->chip.get = gpio_get;
>         bank->chip.direction_output = gpio_output;
> --
> 1.7.7
>

Re: [PATCH] gpio: omap: implement get_direction

[Yegor Yefremov]

On Tue, Apr 22, 2014 at 12:24 PM, Javier Martinez Canillas
<javier@dowhile0.org> wrote:
> Hello Yegor,
>
> On Tue, Apr 22, 2014 at 11:23 AM,  <yegorslists@googlemail.com> wrote:
>> From: Yegor Yefremov <yegorslists@googlemail.com>
>>
>> This patch implements gpio_chip's get_direction() routine, that
>> lets other drivers get particular GPIOs direction using
>> struct gpio_desc.
>>
>> Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
>> ---
>>  drivers/gpio/gpio-omap.c |   28 ++++++++++++++++++++++++++++
>>  1 files changed, 28 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
>> index 19b886c..b55bf7b 100644
>> --- a/drivers/gpio/gpio-omap.c
>> +++ b/drivers/gpio/gpio-omap.c
>> @@ -102,6 +102,20 @@ static int omap_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
>>         return irq_find_mapping(bank->domain, offset);
>>  }
>>
>> +static int _get_gpio_direction(struct gpio_bank *bank, int gpio)
>> +{
>> +       void __iomem *reg = bank->base;
>> +       u32 l;
>> +       u32 mask = 1 << gpio;
>> +
>> +       reg += bank->regs->direction;
>> +       l = readl_relaxed(reg);
>> +       if (l & mask)
>> +               return 1;
>> +
>> +       return 0;
>> +}
>> +
>
> You can avoid the if condition here by using return !!(l & mask) but
> the above code is more clear indeed so is up to you.

Hm, nice trick. I've reworked the calculation in v2.

Yegor