2022-10-07 15:00:22

by Jean-Jacques Hiblot

Subject: [PATCH v4 3/6] leds: provide devm_of_led_get_optional()

This version of devm_of_led_get() doesn't fail if a LED is not found.
Instead it returns a NULL pointer.

Signed-off-by: Jean-Jacques Hiblot <[email protected]>
---
drivers/leds/led-class.c | 25 +++++++++++++++++++++++++
include/linux/leds.h | 2 ++
2 files changed, 27 insertions(+)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 2c0d979d0c8a..2fea79a2300d 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -295,6 +295,31 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
}
EXPORT_SYMBOL_GPL(devm_of_led_get);

+/**
+ * devm_of_led_get_optional - Resource-managed request of an optional LED device
+ * @dev: LED consumer
+ * @index: index of the LED to obtain in the consumer
+ *
+ * The device node of the device is parse to find the request LED device.
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
+ * led was not found.
+ */
+struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
+ int index)
+{
+ struct led_classdev *led;
+
+ led = devm_of_led_get(dev, index);
+ if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
+ return NULL;
+
+ return led;
+}
+EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
+
static int led_classdev_next_name(const char *init_name, char *name,
size_t len)
{
diff --git a/include/linux/leds.h b/include/linux/leds.h
index ba4861ec73d3..41df18f42d00 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -215,6 +215,8 @@ extern struct led_classdev *of_led_get(struct device_node *np, int index);
extern void led_put(struct led_classdev *led_cdev);
struct led_classdev *__must_check devm_of_led_get(struct device *dev,
int index);
+struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
+ int index);

/**
* led_blink_set - set blinking with software fallback
--
2.25.1

2022-10-07 17:00:41

by Andy Shevchenko

Subject: Re: [PATCH v4 3/6] leds: provide devm_of_led_get_optional()

On Fri, Oct 7, 2022 at 5:56 PM Jean-Jacques Hiblot
<[email protected]> wrote:
>
> This version of devm_of_led_get() doesn't fail if a LED is not found.
> Instead it returns a NULL pointer.

Yep, thanks!

Reviewed-by: Andy Shevchenko <[email protected]>

> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> ---
> drivers/leds/led-class.c | 25 +++++++++++++++++++++++++
> include/linux/leds.h | 2 ++
> 2 files changed, 27 insertions(+)
>
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 2c0d979d0c8a..2fea79a2300d 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -295,6 +295,31 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
> }
> EXPORT_SYMBOL_GPL(devm_of_led_get);
>
> +/**
> + * devm_of_led_get_optional - Resource-managed request of an optional LED device

I'm not sure we need to keep "_of" here in the name, but it's not
harmful anyway.

> + * @dev: LED consumer
> + * @index: index of the LED to obtain in the consumer
> + *
> + * The device node of the device is parse to find the request LED device.

I guess you copy'n'pasted this, but this has some spelling issues, I
would change

parse --> parsed
request --> requested

> + * The LED device returned from this function is automatically released
> + * on driver detach.
> + *
> + * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
> + * led was not found.
> + */
> +struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
> + int index)
> +{
> + struct led_classdev *led;
> +
> + led = devm_of_led_get(dev, index);
> + if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
> + return NULL;
> +
> + return led;
> +}
> +EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
> +
> static int led_classdev_next_name(const char *init_name, char *name,
> size_t len)
> {
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index ba4861ec73d3..41df18f42d00 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -215,6 +215,8 @@ extern struct led_classdev *of_led_get(struct device_node *np, int index);
> extern void led_put(struct led_classdev *led_cdev);
> struct led_classdev *__must_check devm_of_led_get(struct device *dev,
> int index);
> +struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
> + int index);
>
> /**
> * led_blink_set - set blinking with software fallback
> --
> 2.25.1
>


--
With Best Regards,
Andy Shevchenko