powerpc/8xx: implement get_direction() in cpm1

[PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Bartosz Golaszewski 4 days, 22 hours ago

The lack of get_direction() callbacks in this driver causes GPIOLIB to
emit a warning. Implement them for 16- and 32-bit variants.

Reported-by: Christophe Leroy <chleroy@kernel.org>
Closes: https://lore.kernel.org/all/63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy@kernel.org/
Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Hi Christophe, please test if this works for you to silence the warning
from GPIO core.
---
 arch/powerpc/platforms/8xx/cpm1.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/powerpc/platforms/8xx/cpm1.c b/arch/powerpc/platforms/8xx/cpm1.c
index f00734f0590cf7c7382f808dce27373d9ff3d8bc..b31376bf6778802a7f6b6b499066846b6b1f61e9 100644
--- a/arch/powerpc/platforms/8xx/cpm1.c
+++ b/arch/powerpc/platforms/8xx/cpm1.c
@@ -472,6 +472,18 @@ static int cpm1_gpio16_dir_in(struct gpio_chip *gc, unsigned int gpio)
 	return 0;
 }
 
+static int cpm1_gpio16_get_direction(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct cpm1_gpio16_chip *cpm1_gc = gpiochip_get_data(gc);
+	struct cpm_ioport16 __iomem *iop = cpm1_gc->regs;
+	u16 pin_mask = 1 << (15 - gpio);
+
+	if (in_be16(&iop->dir) & pin_mask)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
 int cpm1_gpiochip_add16(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
@@ -498,6 +510,7 @@ int cpm1_gpiochip_add16(struct device *dev)
 	gc->ngpio = 16;
 	gc->direction_input = cpm1_gpio16_dir_in;
 	gc->direction_output = cpm1_gpio16_dir_out;
+	gc->get_direction = cpm1_gpio16_get_direction;
 	gc->get = cpm1_gpio16_get;
 	gc->set = cpm1_gpio16_set;
 	gc->to_irq = cpm1_gpio16_to_irq;
@@ -604,6 +617,18 @@ static int cpm1_gpio32_dir_in(struct gpio_chip *gc, unsigned int gpio)
 	return 0;
 }
 
+static int cpm1_gpio32_get_direction(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct cpm1_gpio32_chip *cpm1_gc = gpiochip_get_data(gc);
+	struct cpm_ioport32b __iomem *iop = cpm1_gc->regs;
+	u32 pin_mask = 1 << (31 - gpio);
+
+	if (in_be32(&iop->dir) & pin_mask)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
 int cpm1_gpiochip_add32(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
@@ -621,6 +646,7 @@ int cpm1_gpiochip_add32(struct device *dev)
 	gc->ngpio = 32;
 	gc->direction_input = cpm1_gpio32_dir_in;
 	gc->direction_output = cpm1_gpio32_dir_out;
+	gc->get_direction = cpm1_gpio32_get_direction;
 	gc->get = cpm1_gpio32_get;
 	gc->set = cpm1_gpio32_set;
 	gc->parent = dev;

---
base-commit: b7bee4ca5688e30ca50fbc87b1b8f7eed7006c17
change-id: 20260603-powerpc-8xx-cpm1-get-dir-698cefe92647

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Re: [PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Christophe Leroy (CS GROUP) 3 days, 22 hours ago


Le 03/06/2026 à 10:26, Bartosz Golaszewski a écrit :
> The lack of get_direction() callbacks in this driver causes GPIOLIB to
> emit a warning. Implement them for 16- and 32-bit variants.
> 
> Reported-by: Christophe Leroy <chleroy@kernel.org>
> Closes: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy%40kernel.org%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C67d2207e02454f2ecf0008dec149d67c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639160720043016747%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=k6%2FENNl94WS7QvRdhhmx8VvDyZKMNW8sAlKEq3AtQe4%3D&reserved=0
> Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")

Isn't it e623c4303ed1 ("gpiolib: sanitize the return value of 
gpio_chip::get_direction()") ?

> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> ---
> Hi Christophe, please test if this works for you to silence the warning
> from GPIO core.
> ---
>   arch/powerpc/platforms/8xx/cpm1.c | 26 ++++++++++++++++++++++++++
>   1 file changed, 26 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/8xx/cpm1.c b/arch/powerpc/platforms/8xx/cpm1.c
> index f00734f0590cf7c7382f808dce27373d9ff3d8bc..b31376bf6778802a7f6b6b499066846b6b1f61e9 100644
> --- a/arch/powerpc/platforms/8xx/cpm1.c
> +++ b/arch/powerpc/platforms/8xx/cpm1.c
> @@ -472,6 +472,18 @@ static int cpm1_gpio16_dir_in(struct gpio_chip *gc, unsigned int gpio)
>   	return 0;
>   }
>   
> +static int cpm1_gpio16_get_direction(struct gpio_chip *gc, unsigned int gpio)
> +{
> +	struct cpm1_gpio16_chip *cpm1_gc = gpiochip_get_data(gc);
> +	struct cpm_ioport16 __iomem *iop = cpm1_gc->regs;
> +	u16 pin_mask = 1 << (15 - gpio);
> +
> +	if (in_be16(&iop->dir) & pin_mask)
> +		return GPIO_LINE_DIRECTION_OUT;
> +
> +	return GPIO_LINE_DIRECTION_IN;
> +}
> +
>   int cpm1_gpiochip_add16(struct device *dev)
>   {
>   	struct device_node *np = dev->of_node;
> @@ -498,6 +510,7 @@ int cpm1_gpiochip_add16(struct device *dev)
>   	gc->ngpio = 16;
>   	gc->direction_input = cpm1_gpio16_dir_in;
>   	gc->direction_output = cpm1_gpio16_dir_out;
> +	gc->get_direction = cpm1_gpio16_get_direction;
>   	gc->get = cpm1_gpio16_get;
>   	gc->set = cpm1_gpio16_set;
>   	gc->to_irq = cpm1_gpio16_to_irq;
> @@ -604,6 +617,18 @@ static int cpm1_gpio32_dir_in(struct gpio_chip *gc, unsigned int gpio)
>   	return 0;
>   }
>   
> +static int cpm1_gpio32_get_direction(struct gpio_chip *gc, unsigned int gpio)
> +{
> +	struct cpm1_gpio32_chip *cpm1_gc = gpiochip_get_data(gc);
> +	struct cpm_ioport32b __iomem *iop = cpm1_gc->regs;
> +	u32 pin_mask = 1 << (31 - gpio);
> +
> +	if (in_be32(&iop->dir) & pin_mask)
> +		return GPIO_LINE_DIRECTION_OUT;
> +
> +	return GPIO_LINE_DIRECTION_IN;
> +}
> +
>   int cpm1_gpiochip_add32(struct device *dev)
>   {
>   	struct device_node *np = dev->of_node;
> @@ -621,6 +646,7 @@ int cpm1_gpiochip_add32(struct device *dev)
>   	gc->ngpio = 32;
>   	gc->direction_input = cpm1_gpio32_dir_in;
>   	gc->direction_output = cpm1_gpio32_dir_out;
> +	gc->get_direction = cpm1_gpio32_get_direction;
>   	gc->get = cpm1_gpio32_get;
>   	gc->set = cpm1_gpio32_set;
>   	gc->parent = dev;
> 
> ---
> base-commit: b7bee4ca5688e30ca50fbc87b1b8f7eed7006c17
> change-id: 20260603-powerpc-8xx-cpm1-get-dir-698cefe92647
> 
> Best regards,

Re: [PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Bartosz Golaszewski 3 days, 20 hours ago

On Thu, 4 Jun 2026 10:24:27 +0200, "Christophe Leroy (CS GROUP)"
<chleroy@kernel.org> said:
>
>
> Le 03/06/2026 à 10:26, Bartosz Golaszewski a écrit :
>> The lack of get_direction() callbacks in this driver causes GPIOLIB to
>> emit a warning. Implement them for 16- and 32-bit variants.
>>
>> Reported-by: Christophe Leroy <chleroy@kernel.org>
>> Closes: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy%40kernel.org%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C67d2207e02454f2ecf0008dec149d67c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639160720043016747%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=k6%2FENNl94WS7QvRdhhmx8VvDyZKMNW8sAlKEq3AtQe4%3D&reserved=0

What happened here??

>> Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
>
> Isn't it e623c4303ed1 ("gpiolib: sanitize the return value of
> gpio_chip::get_direction()") ?
>

Sure, can be:

Fixes: e623c4303ed1 ("gpiolib: sanitize the return value of
gpio_chip::get_direction()")

Bart

Re: [PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Christophe Leroy (CS GROUP) 3 days, 20 hours ago


Le 04/06/2026 à 11:53, Bartosz Golaszewski a écrit :
> On Thu, 4 Jun 2026 10:24:27 +0200, "Christophe Leroy (CS GROUP)"
> <chleroy@kernel.org> said:
>>
>>
>> Le 03/06/2026 à 10:26, Bartosz Golaszewski a écrit :
>>> The lack of get_direction() callbacks in this driver causes GPIOLIB to
>>> emit a warning. Implement them for 16- and 32-bit variants.
>>>
>>> Reported-by: Christophe Leroy <chleroy@kernel.org>
>>> Closes: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy%40kernel.org%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C94897fc3d78242b6193308dec21f300e%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639161636389791222%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=an4ji%2Bk24tiNfOASUmnvOyp6kLJzRlH8qhihSkGp%2BVc%3D&reserved=0
> 
> What happened here??

Ask Bill Gates.

My company uses Microsoft 365 outlook, it mangles all links included in 
emails for security reasons they say, to minimise phishing.

> 
>>> Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
>>
>> Isn't it e623c4303ed1 ("gpiolib: sanitize the return value of
>> gpio_chip::get_direction()") ?
>>
> 
> Sure, can be:
> 
> Fixes: e623c4303ed1 ("gpiolib: sanitize the return value of
> gpio_chip::get_direction()")
> 
> Bart

Re: [PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Linus Walleij 3 days, 22 hours ago

On Wed, Jun 3, 2026 at 10:26 AM Bartosz Golaszewski
<bartosz.golaszewski@oss.qualcomm.com> wrote:

> The lack of get_direction() callbacks in this driver causes GPIOLIB to
> emit a warning. Implement them for 16- and 32-bit variants.
>
> Reported-by: Christophe Leroy <chleroy@kernel.org>
> Closes: https://lore.kernel.org/all/63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy@kernel.org/
> Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Re: [PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Linus Walleij 3 days, 22 hours ago

On Wed, Jun 3, 2026 at 10:26 AM Bartosz Golaszewski
<bartosz.golaszewski@oss.qualcomm.com> wrote:

> The lack of get_direction() callbacks in this driver causes GPIOLIB to
> emit a warning. Implement them for 16- and 32-bit variants.
>
> Reported-by: Christophe Leroy <chleroy@kernel.org>
> Closes: https://lore.kernel.org/all/63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy@kernel.org/
> Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij

Re: [PATCH RFT] powerpc/8xx: implement get_direction() in cpm1

Posted by Christophe Leroy (CS GROUP) 3 days, 22 hours ago


Le 03/06/2026 à 10:26, Bartosz Golaszewski a écrit :
> The lack of get_direction() callbacks in this driver causes GPIOLIB to
> emit a warning. Implement them for 16- and 32-bit variants.
> 
> Reported-by: Christophe Leroy <chleroy@kernel.org>
> Closes: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy%40kernel.org%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C67d2207e02454f2ecf0008dec149d67c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C639160720043016747%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=k6%2FENNl94WS7QvRdhhmx8VvDyZKMNW8sAlKEq3AtQe4%3D&reserved=0
> Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Tested-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
> Hi Christophe, please test if this works for you to silence the warning
> from GPIO core.

Hi Bartosz, yes it does, many thanks for the fix.

By the way, wouldn't it also make sense to update the following comment 
in include/linux/gpio/driver.h to change from 'recommended' to 'mandatory' ?

  * @get_direction: returns direction for signal "offset", 0=out, 1=in,
  *	(same as GPIO_LINE_DIRECTION_OUT / GPIO_LINE_DIRECTION_IN),
  *	or negative error. It is recommended to always implement this
  *	function, even on input-only or output-only gpio chips.


> ---
>   arch/powerpc/platforms/8xx/cpm1.c | 26 ++++++++++++++++++++++++++
>   1 file changed, 26 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/8xx/cpm1.c b/arch/powerpc/platforms/8xx/cpm1.c
> index f00734f0590cf7c7382f808dce27373d9ff3d8bc..b31376bf6778802a7f6b6b499066846b6b1f61e9 100644
> --- a/arch/powerpc/platforms/8xx/cpm1.c
> +++ b/arch/powerpc/platforms/8xx/cpm1.c
> @@ -472,6 +472,18 @@ static int cpm1_gpio16_dir_in(struct gpio_chip *gc, unsigned int gpio)
>   	return 0;
>   }
>   
> +static int cpm1_gpio16_get_direction(struct gpio_chip *gc, unsigned int gpio)
> +{
> +	struct cpm1_gpio16_chip *cpm1_gc = gpiochip_get_data(gc);
> +	struct cpm_ioport16 __iomem *iop = cpm1_gc->regs;
> +	u16 pin_mask = 1 << (15 - gpio);
> +
> +	if (in_be16(&iop->dir) & pin_mask)
> +		return GPIO_LINE_DIRECTION_OUT;
> +
> +	return GPIO_LINE_DIRECTION_IN;
> +}
> +
>   int cpm1_gpiochip_add16(struct device *dev)
>   {
>   	struct device_node *np = dev->of_node;
> @@ -498,6 +510,7 @@ int cpm1_gpiochip_add16(struct device *dev)
>   	gc->ngpio = 16;
>   	gc->direction_input = cpm1_gpio16_dir_in;
>   	gc->direction_output = cpm1_gpio16_dir_out;
> +	gc->get_direction = cpm1_gpio16_get_direction;
>   	gc->get = cpm1_gpio16_get;
>   	gc->set = cpm1_gpio16_set;
>   	gc->to_irq = cpm1_gpio16_to_irq;
> @@ -604,6 +617,18 @@ static int cpm1_gpio32_dir_in(struct gpio_chip *gc, unsigned int gpio)
>   	return 0;
>   }
>   
> +static int cpm1_gpio32_get_direction(struct gpio_chip *gc, unsigned int gpio)
> +{
> +	struct cpm1_gpio32_chip *cpm1_gc = gpiochip_get_data(gc);
> +	struct cpm_ioport32b __iomem *iop = cpm1_gc->regs;
> +	u32 pin_mask = 1 << (31 - gpio);
> +
> +	if (in_be32(&iop->dir) & pin_mask)
> +		return GPIO_LINE_DIRECTION_OUT;
> +
> +	return GPIO_LINE_DIRECTION_IN;
> +}
> +
>   int cpm1_gpiochip_add32(struct device *dev)
>   {
>   	struct device_node *np = dev->of_node;
> @@ -621,6 +646,7 @@ int cpm1_gpiochip_add32(struct device *dev)
>   	gc->ngpio = 32;
>   	gc->direction_input = cpm1_gpio32_dir_in;
>   	gc->direction_output = cpm1_gpio32_dir_out;
> +	gc->get_direction = cpm1_gpio32_get_direction;
>   	gc->get = cpm1_gpio32_get;
>   	gc->set = cpm1_gpio32_set;
>   	gc->parent = dev;
> 
> ---
> base-commit: b7bee4ca5688e30ca50fbc87b1b8f7eed7006c17
> change-id: 20260603-powerpc-8xx-cpm1-get-dir-698cefe92647
> 
> Best regards,