[PATCH 1/2] gpio: unify gpio direction macros names with Linux kernel

[PATCH 1/2] gpio: unify gpio direction macros names with Linux kernel

[Antony Pavlov]

See linux.git/include/linux/gpio.h and
linux.git/Documentation/gpio.txt for details.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 drivers/gpio/gpio-dw.c | 2 +-
 include/gpio.h         | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-dw.c b/drivers/gpio/gpio-dw.c
index 6577042..e46cc8e 100644
--- a/drivers/gpio/gpio-dw.c
+++ b/drivers/gpio/gpio-dw.c
@@ -95,7 +95,7 @@ static int dw_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
 	struct dw_gpio_instance *chip = to_dw_gpio(gc);
 
 	return (readl(chip->regs + DW_GPIO_DDR) & (1 << offset)) ?
-		GPIO_DIR_OUT : GPIO_DIR_IN;
+		GPIOF_DIR_OUT : GPIOF_DIR_IN;
 }
 
 static struct gpio_ops imx_gpio_ops = {
diff --git a/include/gpio.h b/include/gpio.h
index 708b2aa..f33b435 100644
--- a/include/gpio.h
+++ b/include/gpio.h
@@ -3,8 +3,8 @@
 
 #include <asm/gpio.h>
 
-#define GPIO_DIR_OUT	(0 << 0)
-#define GPIO_DIR_IN	(1 << 0)
+#define GPIOF_DIR_OUT	(0 << 0)
+#define GPIOF_DIR_IN	(1 << 0)
 
 #ifndef CONFIG_GPIOLIB
 static inline int gpio_request(unsigned gpio, const char *label)
-- 
1.8.4.2


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[PATCH 2/2] gpiolib: import gpio_request_array() from linux 3.7

[Antony Pavlov]

Also import related functions gpio_request_one() and
gpio_free_array().

This commit imports code from linux 3.7 as
the more recent linux kernel versions use gpiolib descriptors,
see this commit for details:

  commit 372e722ea4dd4ca11c3d04845e11cbc15f32144c
  Author: Alexandre Courbot <acourbot@nvidia.com>
  Date:   Sun Feb 3 01:29:29 2013 +0900

      gpiolib: use descriptors internally

      Make sure gpiolib works internally with descriptors and (chip, offset)
      pairs instead of using the global integer namespace. This prepares the
      ground for the removal of the global gpio_desc[] array and the
      introduction of the descriptor-based GPIO API.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 drivers/gpio/gpiolib.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/gpio.h         | 39 +++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b7db596..8168bd3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -85,6 +85,72 @@ void gpio_free(unsigned gpio)
 	free(gi->label);
 }
 
+/**
+ * gpio_request_one - request a single GPIO with initial configuration
+ * @gpio:	the GPIO number
+ * @flags:	GPIO configuration as specified by GPIOF_*
+ * @label:	a literal description string of this GPIO
+ */
+int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
+{
+	int err;
+
+	err = gpio_request(gpio, label);
+	if (err)
+		return err;
+
+	if (flags & GPIOF_DIR_IN)
+		err = gpio_direction_input(gpio);
+	else
+		err = gpio_direction_output(gpio,
+				(flags & GPIOF_INIT_HIGH) ? 1 : 0);
+
+	if (err)
+		goto free_gpio;
+
+	return 0;
+
+ free_gpio:
+	gpio_free(gpio);
+	return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_one);
+
+/**
+ * gpio_request_array - request multiple GPIOs in a single call
+ * @array:	array of the 'struct gpio'
+ * @num:	how many GPIOs in the array
+ */
+int gpio_request_array(const struct gpio *array, size_t num)
+{
+	int i, err;
+
+	for (i = 0; i < num; i++, array++) {
+		err = gpio_request_one(array->gpio, array->flags, array->label);
+		if (err)
+			goto err_free;
+	}
+	return 0;
+
+err_free:
+	while (i--)
+		gpio_free((--array)->gpio);
+	return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_array);
+
+/**
+ * gpio_free_array - release multiple GPIOs in a single call
+ * @array:	array of the 'struct gpio'
+ * @num:	how many GPIOs in the array
+ */
+void gpio_free_array(const struct gpio *array, size_t num)
+{
+	while (num--)
+		gpio_free((array++)->gpio);
+}
+EXPORT_SYMBOL_GPL(gpio_free_array);
+
 void gpio_set_value(unsigned gpio, int value)
 {
 	struct gpio_info *gi = gpio_to_desc(gpio);
diff --git a/include/gpio.h b/include/gpio.h
index f33b435..b851e85 100644
--- a/include/gpio.h
+++ b/include/gpio.h
@@ -6,6 +6,25 @@
 #define GPIOF_DIR_OUT	(0 << 0)
 #define GPIOF_DIR_IN	(1 << 0)
 
+#define GPIOF_INIT_LOW	(0 << 1)
+#define GPIOF_INIT_HIGH	(1 << 1)
+
+#define GPIOF_IN		(GPIOF_DIR_IN)
+#define GPIOF_OUT_INIT_LOW	(GPIOF_DIR_OUT | GPIOF_INIT_LOW)
+#define GPIOF_OUT_INIT_HIGH	(GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
+
+/**
+ * struct gpio - a structure describing a GPIO with configuration
+ * @gpio:	the GPIO number
+ * @flags:	GPIO configuration as specified by GPIOF_*
+ * @label:	a literal description string of this GPIO
+ */
+struct gpio {
+	unsigned	gpio;
+	unsigned long	flags;
+	const char	*label;
+};
+
 #ifndef CONFIG_GPIOLIB
 static inline int gpio_request(unsigned gpio, const char *label)
 {
@@ -15,9 +34,29 @@ static inline int gpio_request(unsigned gpio, const char *label)
 static inline void gpio_free(unsigned gpio)
 {
 }
+
+static inline int gpio_request_one(unsigned gpio,
+					unsigned long flags, const char *label)
+{
+	return 0;
+}
+
+static inline int gpio_request_array(const struct gpio *array, size_t num)
+{
+	return 0;
+}
+
+static inline void gpio_free_array(const struct gpio *array, size_t num)
+{
+	/* GPIO can never have been requested */
+	WARN_ON(1);
+}
 #else
 int gpio_request(unsigned gpio, const char *label);
 void gpio_free(unsigned gpio);
+int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
+int gpio_request_array(const struct gpio *array, size_t num);
+void gpio_free_array(const struct gpio *array, size_t num);
 #endif
 
 struct gpio_chip;
-- 
1.8.4.2


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Re: [PATCH 2/2] gpiolib: import gpio_request_array() from linux 3.7

[Sascha Hauer]

Hi Antony,

On Fri, Nov 22, 2013 at 12:11:24AM +0400, Antony Pavlov wrote:
> Also import related functions gpio_request_one() and
> gpio_free_array().
> 
> This commit imports code from linux 3.7 as
> the more recent linux kernel versions use gpiolib descriptors,
> see this commit for details:
> 
>   commit 372e722ea4dd4ca11c3d04845e11cbc15f32144c
>   Author: Alexandre Courbot <acourbot@nvidia.com>
>   Date:   Sun Feb 3 01:29:29 2013 +0900
> 
>       gpiolib: use descriptors internally
> 
>       Make sure gpiolib works internally with descriptors and (chip, offset)
>       pairs instead of using the global integer namespace. This prepares the
>       ground for the removal of the global gpio_desc[] array and the
>       introduction of the descriptor-based GPIO API.
> 
> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>

What a pitty, we duplicated some work. I created exactly the same patch
recently but haven't posted it yet, shame on me.

> +static inline int gpio_request_one(unsigned gpio,
> +					unsigned long flags, const char *label)
> +{
> +	return 0;
> +}
> +
> +static inline int gpio_request_array(const struct gpio *array, size_t num)
> +{
> +	return 0;
> +}
> +

That's the only place our patches differ. In my version I return -ENOSYS
since gpio_request_one() and gpio_request_array() not only request gpios
but also configure them. We can't return success without configuring the
gpios. I applied your version but with -ENOSYS here.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
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Re: [PATCH 2/2] gpiolib: import gpio_request_array() from linux 3.7

[Antony N. Pavlov]

On Fri, 22 Nov 2013 08:20:08 +0100
Sascha Hauer <s.hauer@pengutronix.de> wrote:

> Hi Antony,
> 
> On Fri, Nov 22, 2013 at 12:11:24AM +0400, Antony Pavlov wrote:
> > Also import related functions gpio_request_one() and
> > gpio_free_array().
> > 
> > This commit imports code from linux 3.7 as
> > the more recent linux kernel versions use gpiolib descriptors,
> > see this commit for details:
> > 
> >   commit 372e722ea4dd4ca11c3d04845e11cbc15f32144c
> >   Author: Alexandre Courbot <acourbot@nvidia.com>
> >   Date:   Sun Feb 3 01:29:29 2013 +0900
> > 
> >       gpiolib: use descriptors internally
> > 
> >       Make sure gpiolib works internally with descriptors and (chip, offset)
> >       pairs instead of using the global integer namespace. This prepares the
> >       ground for the removal of the global gpio_desc[] array and the
> >       introduction of the descriptor-based GPIO API.
> > 
> > Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> 
> What a pitty, we duplicated some work. I created exactly the same patch
> recently but haven't posted it yet, shame on me.

I must say "Thanks!" to Sebastian Hesselbarth. It's him who introduced
get_direction callback. His patch conflicted with patch in my local repo.
So I made the decision to post my patch as soon as possible.


> > +static inline int gpio_request_one(unsigned gpio,
> > +					unsigned long flags, const char *label)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline int gpio_request_array(const struct gpio *array, size_t num)
> > +{
> > +	return 0;
> > +}
> > +
> 
> That's the only place our patches differ. In my version I return -ENOSYS
> since gpio_request_one() and gpio_request_array() not only request gpios
> but also configure them. We can't return success without configuring the
> gpios. I applied your version but with -ENOSYS here.
> 
> Sascha
> 
> -- 
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox


-- 
С уважением,
  Павлов Антон

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Re: [PATCH 2/2] gpiolib: import gpio_request_array() from linux 3.7

[Sebastian Hesselbarth]

On 11/22/2013 08:49 AM, Antony N. Pavlov wrote:
> On Fri, 22 Nov 2013 08:20:08 +0100
> Sascha Hauer <s.hauer@pengutronix.de> wrote:
>
>> Hi Antony,
>>
>> On Fri, Nov 22, 2013 at 12:11:24AM +0400, Antony Pavlov wrote:
>>> Also import related functions gpio_request_one() and
>>> gpio_free_array().
>>>
>>> This commit imports code from linux 3.7 as
>>> the more recent linux kernel versions use gpiolib descriptors,
>>> see this commit for details:
>>>
>>>    commit 372e722ea4dd4ca11c3d04845e11cbc15f32144c
>>>    Author: Alexandre Courbot <acourbot@nvidia.com>
>>>    Date:   Sun Feb 3 01:29:29 2013 +0900
>>>
>>>        gpiolib: use descriptors internally
>>>
>>>        Make sure gpiolib works internally with descriptors and (chip, offset)
>>>        pairs instead of using the global integer namespace. This prepares the
>>>        ground for the removal of the global gpio_desc[] array and the
>>>        introduction of the descriptor-based GPIO API.
>>>
>>> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
>>
>> What a pitty, we duplicated some work. I created exactly the same patch
>> recently but haven't posted it yet, shame on me.
>
> I must say "Thanks!" to Sebastian Hesselbarth. It's him who introduced
> get_direction callback. His patch conflicted with patch in my local repo.
> So I made the decision to post my patch as soon as possible.

I added that callback because I needed it for working on Marvell Berlin
support. Don't expect too fancy stuff, but as soon as I find some time
to work out the Chipidea USB device driver, I'll be posting patches for
Chromecast.

The get_direction callback gives valuable information for unknown HW :P

Sebastian

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