[PATCH] gpio: ixp4xx: switch to dynamic GPIO base

[PATCH] gpio: ixp4xx: switch to dynamic GPIO base

[Mohamed Ayman]

Most IXP4xx platforms are Device Tree-based, and GPIO consumers
use phandle-based descriptors rather than legacy integer GPIO numbers.

Audit of the IXP4xx platform shows:
- No gpio_request(), gpio_get_value(), or gpio_set_value() users
  in arch/arm/mach-ixp4xx/
- No platform data using fixed GPIO numbers

This switches the gpiochip to dynamic base allocation, aligning
with modern gpiolib expectations where GPIO numbers are not globally
fixed and may be assigned dynamically.

Set gpiochip.base = -1 to allow gpiolib to assign the GPIO base
dynamically, avoiding global GPIO number space conflicts.

Signed-off-by: Mohamed Ayman <mohamedaymanworkspace@gmail.com>
---
 drivers/gpio/gpio-ixp4xx.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-ixp4xx.c b/drivers/gpio/gpio-ixp4xx.c
index f34d87869c8b..669b139cd499 100644
--- a/drivers/gpio/gpio-ixp4xx.c
+++ b/drivers/gpio/gpio-ixp4xx.c
@@ -311,12 +311,7 @@ static int ixp4xx_gpio_probe(struct platform_device *pdev)
 	}
 	g->chip.gc.ngpio = 16;
 	g->chip.gc.label = "IXP4XX_GPIO_CHIP";
-	/*
-	 * TODO: when we have migrated to device tree and all GPIOs
-	 * are fetched using phandles, set this to -1 to get rid of
-	 * the fixed gpiochip base.
-	 */
-	g->chip.gc.base = 0;
+	g->chip.gc.base = -1;
 	g->chip.gc.parent = &pdev->dev;
 	g->chip.gc.owner = THIS_MODULE;
 
-- 
2.34.1

Re: [PATCH] gpio: ixp4xx: switch to dynamic GPIO base

[Linus Walleij]

On Mon, Apr 27, 2026 at 11:43 PM Mohamed Ayman
<mohamedaymanworkspace@gmail.com> wrote:

> Most IXP4xx platforms are Device Tree-based, and GPIO consumers
> use phandle-based descriptors rather than legacy integer GPIO numbers.
>
> Audit of the IXP4xx platform shows:
> - No gpio_request(), gpio_get_value(), or gpio_set_value() users
>   in arch/arm/mach-ixp4xx/
> - No platform data using fixed GPIO numbers
>
> This switches the gpiochip to dynamic base allocation, aligning
> with modern gpiolib expectations where GPIO numbers are not globally
> fixed and may be assigned dynamically.
>
> Set gpiochip.base = -1 to allow gpiolib to assign the GPIO base
> dynamically, avoiding global GPIO number space conflicts.
>
> Signed-off-by: Mohamed Ayman <mohamedaymanworkspace@gmail.com>

You're right and you beat me to it! No-one is dependent on the
fixed GPIO numbering for this platform.
Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij

Re: [PATCH] gpio: ixp4xx: switch to dynamic GPIO base

[Bartosz Golaszewski]

On Tue, 28 Apr 2026 00:43:10 +0300, Mohamed Ayman wrote:
> Most IXP4xx platforms are Device Tree-based, and GPIO consumers
> use phandle-based descriptors rather than legacy integer GPIO numbers.
> 
> Audit of the IXP4xx platform shows:
> - No gpio_request(), gpio_get_value(), or gpio_set_value() users
>   in arch/arm/mach-ixp4xx/
> - No platform data using fixed GPIO numbers
> 
> [...]

Applied, thanks!

[1/1] gpio: ixp4xx: switch to dynamic GPIO base
      https://git.kernel.org/brgl/c/1005d6e0257a5623ef79bfbd8f588b498c1cab0d

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