[PATCH] [v2] leds: gpio: make legacy gpiolib interface optional

Arnd Bergmann
2026-04-30T09:12:13Z

From: Arnd Bergmann <arnd@arndb.de>

There are still a handful of ancient mips/armv5/sh boards that use the
gpio_led:gpio member to pass an old-style gpio number, but all modern
users have been converted to gpio descriptors.

While the CONFIG_GPIOLIB_LEGACY option that guards devm_gpio_request_one()
and related helpers is currently turned on in all kernel builds,
the plan is to only enable it on the few platforms that actually
pass gpio numbers in any platform_data.

Split out the legacy portion of the platform_data handling into a custom
helper function that is guarded with in #ifdef block, to allow the
the leds-gpio driver to compile cleanly when CONFIG_GPIOLIB_LEGACY
gets turned off. Once the last user is converted, this function can
be removed.

Link: https://lore.kernel.org/all/e9252384-a55c-4a91-9c61-06e05a0b2ce4@app.fastmail.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: rework a little bit to keep the legacy code path more separate,
extend changelog description

Related to this, we may also want to remove support for passing
a gpio descriptor in the ->gpiod flag. The only user doing this
at the moment was introduced in commit 1892e87a3e91 ("powerpc/warp:
switch to using gpiod API").

Linus Walleij previously gave a Reviewed-by tag, but I dropped
it again during the rework.
---
drivers/leds/leds-gpio.c | 48 +++++++++++++++++++++++++++++-----------
include/linux/leds.h | 2 ++
2 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 961acc18d0ac..788d9ef7720a 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -212,7 +212,6 @@ static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
const struct gpio_led *template)
{
struct gpio_desc *gpiod;
- int ret;

/*
* This means the LED does not come from the device tree
@@ -228,11 +227,27 @@ static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
return gpiod;
}

- /*
- * This is the legacy code path for platform code that
- * still uses GPIO numbers. Ultimately we would like to get
- * rid of this block completely.
- */
+ return gpiod;
+}
+
+#ifdef CONFIG_GPIOLIB_LEGACY
+/*
+ * This is the legacy code path for platform code that still uses
+ * GPIO numbers, mainly MIPS and SuperH board files.
+ * Ultimately we would like to get rid of this block completely.
+ *
+ * ppc44x-warp sets the template->gpiod directly instead of
+ * adding a lookup table or device properties. This is not
+ * much better.
+ */
+static struct gpio_desc *gpio_led_get_legacy_gpiod(struct device *dev, int idx,
+ const struct gpio_led *template)
+{
+ struct gpio_desc *gpiod;
+ int ret;
+
+ if (template->gpiod)
+ return template->gpiod;

/* skip leds that aren't available */
if (!gpio_is_valid(template->gpio))
@@ -252,6 +267,13 @@ static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,

return gpiod;
}
+#else
+static struct gpio_desc *gpio_led_get_legacy_gpiod(struct device *dev, int idx,
+ const struct gpio_led *template)
+{
+ return template->gpiod;
+}
+#endif

static int gpio_led_probe(struct platform_device *pdev)
{
@@ -270,14 +292,14 @@ static int gpio_led_probe(struct platform_device *pdev)
const struct gpio_led *template = &pdata->leds[i];
struct gpio_led_data *led_dat = &priv->leds[i];

- if (template->gpiod)
- led_dat->gpiod = template->gpiod;
- else
- led_dat->gpiod =
- gpio_led_get_gpiod(dev, i, template);
+ led_dat->gpiod = gpio_led_get_gpiod(dev, i, template);
+ if (!led_dat->gpiod)
+ led_dat->gpiod = gpio_led_get_legacy_gpiod(dev,
+ i, template);
+
if (IS_ERR(led_dat->gpiod)) {
- dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
- template->gpio, template->name);
+ dev_info(dev, "Skipping unavailable LED gpio %s\n",
+ template->name);
continue;
}

diff --git a/include/linux/leds.h b/include/linux/leds.h
index b16b803cc1ac..e646bffcd8e7 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -676,8 +676,10 @@ typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
struct gpio_led {
const char *name;
const char *default_trigger;
+#ifdef CONFIG_GPIOLIB_LEGACY
unsigned gpio;
unsigned active_low : 1;
+#endif
unsigned retain_state_suspended : 1;
unsigned panic_indicator : 1;
unsigned default_state : 2;
--
2.39.5