From a96aa64cb5723d941de879a9cd1fea025d6acb1b Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Delgado Date: Mon, 30 Mar 2015 10:45:59 -0700 Subject: [PATCH] leds/led-class: Handle LEDs with the same name The current code expected that every LED had an unique name. This is a legit expectation when the device tree can no be modified or extended. But with device tree overlays this requirement can be easily broken. This patch finds out if the name is already in use and adds the suffix _1, _2... if not. Signed-off-by: Ricardo Ribalda Delgado Reported-by: Geert Uytterhoeven Signed-off-by: Bryan Wu --- drivers/leds/led-class.c | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 768d33a79881..fc57d9c2e6ad 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -212,6 +212,31 @@ static const struct dev_pm_ops leds_class_dev_pm_ops = { .resume = led_resume, }; +static int match_name(struct device *dev, const void *data) +{ + if (!dev_name(dev)) + return 0; + return !strcmp(dev_name(dev), (char *)data); +} + +static int led_classdev_next_name(const char *init_name, char *name, + size_t len) +{ + unsigned int i = 0; + int ret = 0; + + strlcpy(name, init_name, len); + + while (class_find_device(leds_class, NULL, name, match_name) && + (ret < len)) + ret = snprintf(name, len, "%s_%u", init_name, ++i); + + if (ret >= len) + return -ENOMEM; + + return i; +} + /** * led_classdev_register - register a new object of led_classdev class. * @parent: The device to register. @@ -219,12 +244,22 @@ static const struct dev_pm_ops leds_class_dev_pm_ops = { */ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) { + char name[64]; + int ret; + + ret = led_classdev_next_name(led_cdev->name, name, sizeof(name)); + if (ret < 0) + return ret; + led_cdev->dev = device_create_with_groups(leds_class, parent, 0, - led_cdev, led_cdev->groups, - "%s", led_cdev->name); + led_cdev, led_cdev->groups, name); if (IS_ERR(led_cdev->dev)) return PTR_ERR(led_cdev->dev); + if (ret) + dev_info(parent, "Led %s renamed to %s due to name collision", + led_cdev->name, dev_name(led_cdev->dev)); + #ifdef CONFIG_LEDS_TRIGGERS init_rwsem(&led_cdev->trigger_lock); #endif -- 2.20.1