linux-kernel - [PATCH v11 2/5] leds: provide devm_of_led_get

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Message-ID: <20230718092527.37516-3-jjhiblot@traphandler.com>
Date:   Tue, 18 Jul 2023 11:25:24 +0200
From:   Jean-Jacques Hiblot <jjhiblot@...phandler.com>
To:     <lee@...nel.org>, <pavel@....cz>, <robh+dt@...nel.org>,
        <krzysztof.kozlowski+dt@...aro.org>, <conor+dt@...nel.org>
CC:     <linux-leds@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        Jean-Jacques Hiblot <jjhiblot@...phandler.com>,
        Andy Shevchenko <andy.shevchenko@...il.com>
Subject: [PATCH v11 2/5] leds: provide devm_of_led_get_optional()

Add an optional variant of devm_of_led_get(). It behaves the same as
devm_of_led_get() except where the LED doesn't exist. In this case,
instead of returning -ENOENT, the function returns NULL.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@...phandler.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>
---
 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 6dae56b914fe..eb1a8494dc5b 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -402,6 +402,31 @@ void led_remove_lookup(struct led_lookup_data *led_lookup)
 }
 EXPORT_SYMBOL_GPL(led_remove_lookup);
 
+/**
+ * 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 parsed to find the requested 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 50b2f8f153fb..95311c70d95c 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -270,6 +270,8 @@ 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
-- 
2.34.1