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

From: Bartosz Golaszewski

Date: Wed Jun 03 2026 - 04:31:08 EST


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@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/63487206f6e5a93eaf9f41784317fe99d394312f.1780399750.git.chleroy@xxxxxxxxxx/
Fixes: ec2cceadfae7 ("gpiolib: normalize the return value of gc->get() on behalf of buggy drivers")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxxxx>