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From: Jean-Jacques Hiblot <jjhiblot@ti.com>
To: <jacek.anaszewski@gmail.com>, <pavel@ucw.cz>, <sre@kernel.org>,
	<robh+dt@kernel.org>, <mark.rutland@arm.com>,
	<lee.jones@linaro.org>, <daniel.thompson@linaro.org>
Cc: <dmurphy@ti.com>, <linux-leds@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
	<tomi.valkeinen@ti.com>, Jean-Jacques Hiblot <jjhiblot@ti.com>
Subject: [PATCH v9 3/5] leds: Add managed API to get a LED from a device driver
Date: Mon, 7 Oct 2019 14:44:35 +0200
Message-ID: <20191007124437.20367-4-jjhiblot@ti.com> (raw)
In-Reply-To: <20191007124437.20367-1-jjhiblot@ti.com>

If the LED is acquired by a consumer device with devm_led_get(), it is
automatically released when the device is detached.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
 drivers/leds/led-class.c | 49 ++++++++++++++++++++++++++++++++++++++++
 include/linux/leds.h     |  2 ++
 2 files changed, 51 insertions(+)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 1d1f1d546dc7..639224392ffa 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -264,6 +264,55 @@ void led_put(struct led_classdev *led_cdev)
 }
 EXPORT_SYMBOL_GPL(led_put);
 
+static void devm_led_release(struct device *dev, void *res)
+{
+	struct led_classdev **p = res;
+
+	led_put(*p);
+}
+
+/**
+ * devm_of_led_get - Resource-managed request of a 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 or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *__must_check devm_of_led_get(struct device *dev,
+						  int index)
+{
+	struct led_classdev *led;
+	struct led_classdev **dr;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	/* Consummer not using device tree? */
+	if (!dev_of_node(dev))
+		return ERR_PTR(-ENOTSUPP);
+
+	led = of_led_get(dev_of_node(dev), index);
+	if (IS_ERR(led))
+		return led;
+
+	dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
+			  GFP_KERNEL);
+	if (!dr) {
+		led_put(led);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*dr = led;
+	devres_add(dev, dr);
+
+	return led;
+}
+EXPORT_SYMBOL_GPL(devm_of_led_get);
+
 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 6f7371bc7757..9b94cf752012 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -199,6 +199,8 @@ extern void led_classdev_resume(struct led_classdev *led_cdev);
 
 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);
 
 /**
  * led_blink_set - set blinking with software fallback
-- 
2.17.1


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-07 12:44 [PATCH v9 0/5] Add a generic driver for LED-based backlight Jean-Jacques Hiblot
2019-10-07 12:44 ` [PATCH v9 1/5] leds: populate the device's of_node Jean-Jacques Hiblot
2019-10-07 12:44 ` [PATCH v9 2/5] leds: Add of_led_get() and led_put() Jean-Jacques Hiblot
2019-10-07 12:44 ` Jean-Jacques Hiblot [this message]
2019-10-13 12:09   ` [PATCH v9 3/5] leds: Add managed API to get a LED from a device driver Pavel Machek
2019-10-07 12:44 ` [PATCH v9 4/5] dt-bindings: backlight: Add led-backlight binding Jean-Jacques Hiblot
2019-10-07 16:15   ` Rob Herring
2019-10-08 12:51     ` Jean-Jacques Hiblot
2019-10-08 13:30       ` Jean-Jacques Hiblot
2019-10-08 15:00         ` Rob Herring
2019-10-08 17:17           ` Jacek Anaszewski
2019-10-08 17:17           ` Jacek Anaszewski
2019-10-08 20:00             ` Rob Herring
2019-10-09 18:31               ` Jacek Anaszewski
2019-10-08 14:52       ` Rob Herring
2019-10-07 12:44 ` [PATCH v9 5/5] backlight: add led-backlight driver Jean-Jacques Hiblot

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