[PATCH 0/2] gpio: pl061: hook request if gpio-ranges avaiable

[PATCH 0/2] gpio: pl061: hook request if gpio-ranges avaiable

[Yunlei He]

Hi,

This series includes two patches for sloving pinctrl_request_gpio() returns
EPROBE_DEFER problem. We find this problem when we use gpio device without
"gpio-ranges" property in gpio device node. 

 - First patch provides solutions to this problem
 
 - Second patch documents gpio-ranges property for bindings file.

Yunlei He (2):
  gpio: pl061: hook request if gpio-ranges avaiable
  gpio: pl061: document gpio-ranges property for bindings file

 .../devicetree/bindings/gpio/pl061-gpio.txt          |  2 +-
 drivers/gpio/gpio-pl061.c                            | 20 ++++++++++++++------
 2 files changed, 15 insertions(+), 7 deletions(-)

-- 
1.9.1

[PATCH 1/2] gpio: pl061: hook request if gpio-ranges avaiable

[Yunlei He]

Gpio-ranges property is useful to represent which GPIOs correspond
to which pins on which pin controllers. But there may be some gpios
without pinctrl operation. So check whether gpio-ranges property
exists in device node first.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
---
 drivers/gpio/gpio-pl061.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
index 84b49cf..15d1885 100644
--- a/drivers/gpio/gpio-pl061.c
+++ b/drivers/gpio/gpio-pl061.c
@@ -52,28 +52,34 @@ struct pl061_gpio {
 
 	void __iomem		*base;
 	struct gpio_chip	gc;
+	bool			uses_pinctrl;
 
 #ifdef CONFIG_PM
 	struct pl061_context_save_regs csave_regs;
 #endif
 };
 
-static int pl061_gpio_request(struct gpio_chip *chip, unsigned offset)
+static int pl061_gpio_request(struct gpio_chip *gc, unsigned offset)
 {
 	/*
 	 * Map back to global GPIO space and request muxing, the direction
 	 * parameter does not matter for this controller.
 	 */
-	int gpio = chip->base + offset;
+	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+	int gpio = gc->base + offset;
 
-	return pinctrl_request_gpio(gpio);
+	if (chip->uses_pinctrl)
+		return pinctrl_request_gpio(gpio);
+	return 0;
 }
 
-static void pl061_gpio_free(struct gpio_chip *chip, unsigned offset)
+static void pl061_gpio_free(struct gpio_chip *gc, unsigned offset)
 {
-	int gpio = chip->base + offset;
+	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+	int gpio = gc->base + offset;
 
-	pinctrl_free_gpio(gpio);
+	if (chip->uses_pinctrl)
+		pinctrl_free_gpio(gpio);
 }
 
 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
@@ -263,6 +269,8 @@ static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 		return PTR_ERR(chip->base);
 
 	spin_lock_init(&chip->lock);
+	if (of_property_read_bool(dev->of_node, "gpio-ranges"))
+		chip->uses_pinctrl = true;
 
 	chip->gc.request = pl061_gpio_request;
 	chip->gc.free = pl061_gpio_free;
-- 
1.9.1

[PATCH 2/2] gpio: pl061: document gpio-ranges property for bindings file

[Yunlei He]

Document gpio-ranges property in pl061-gpio.txt

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
---
 Documentation/devicetree/bindings/gpio/pl061-gpio.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
index a2c416b..89058d3 100644
--- a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
@@ -7,4 +7,4 @@ Required properties:
   - bit 0 specifies polarity (0 for normal, 1 for inverted)
 - gpio-controller : Marks the device node as a GPIO controller.
 - interrupts : Interrupt mapping for GPIO IRQ.
-
+- gpio-ranges : Interaction with the PINCTRL subsystem.
-- 
1.9.1

Re: [PATCH 1/2] gpio: pl061: hook request if gpio-ranges avaiable

[Linus Walleij]

On Tue, Dec 2, 2014 at 5:32 AM, Yunlei He <heyunlei@huawei.com> wrote:

> Gpio-ranges property is useful to represent which GPIOs correspond
> to which pins on which pin controllers. But there may be some gpios
> without pinctrl operation. So check whether gpio-ranges property
> exists in device node first.
>
> Signed-off-by: Yunlei He <heyunlei@huawei.com>
> Signed-off-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

Yep simple and elegant.

Patch applied.

However I wonder if it would be possible to move this to the
gpiolib.c or gpiolib-of.c core so not all drivers with this problem
has to implement it.

Yours,
Linus Walleij

Re: [PATCH 2/2] gpio: pl061: document gpio-ranges property for bindings file

[Linus Walleij]

On Tue, Dec 2, 2014 at 5:33 AM, Yunlei He <heyunlei@huawei.com> wrote:

> Document gpio-ranges property in pl061-gpio.txt
>
> Signed-off-by: Yunlei He <heyunlei@huawei.com>
> Signed-off-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

Patch applied.

Yours,
Linus Walleij

Re: [PATCH 1/2] gpio: pl061: hook request if gpio-ranges avaiable

[He YunLei]

On 2014/12/3 21:45, Linus Walleij wrote:
> On Tue, Dec 2, 2014 at 5:32 AM, Yunlei He <heyunlei@huawei.com> wrote:
>
>> Gpio-ranges property is useful to represent which GPIOs correspond
>> to which pins on which pin controllers. But there may be some gpios
>> without pinctrl operation. So check whether gpio-ranges property
>> exists in device node first.
>>
>> Signed-off-by: Yunlei He <heyunlei@huawei.com>
>> Signed-off-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
>> Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
>
> Yep simple and elegant.
>
> Patch applied.
>
> However I wonder if it would be possible to move this to the
> gpiolib.c or gpiolib-of.c core so not all drivers with this problem
> has to implement it.
>
> Yours,
> Linus Walleij
>
>
Thanks for your suggest, I can move this judgement to the gpiolib.c in function
gpio_request() along with a symbol uses_pinctrl in struct gpio_chip. But the symbol
uses_pinctrl still need to assign a value in device initial time. So I think that drivers
do this separately is better.

Yours,
Yunlei