From 445110941eb94709216363f9d807d2508e64abd7 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 20 Jan 2023 12:45:14 +0100 Subject: leds: led-class: Add missing put_device() to led_put() led_put() is used to "undo" a successful of_led_get() call, of_led_get() uses class_find_device_by_of_node() which returns a reference to the device which must be free-ed with put_device() when the caller is done with it. Add a put_device() call to led_put() to free the reference returned by class_find_device_by_of_node(). And also add a put_device() in the error-exit case of try_module_get() failing. Fixes: 699a8c7c4bd3 ("leds: Add of_led_get() and led_put()") Reviewed-by: Andy Shevchenko Reviewed-by: Linus Walleij Signed-off-by: Hans de Goede Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20230120114524.408368-2-hdegoede@redhat.com --- drivers/leds/led-class.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/leds') diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 6a8ea94834fa..7391d2cf1370 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -241,8 +241,10 @@ struct led_classdev *of_led_get(struct device_node *np, int index) led_cdev = dev_get_drvdata(led_dev); - if (!try_module_get(led_cdev->dev->parent->driver->owner)) + if (!try_module_get(led_cdev->dev->parent->driver->owner)) { + put_device(led_cdev->dev); return ERR_PTR(-ENODEV); + } return led_cdev; } @@ -255,6 +257,7 @@ EXPORT_SYMBOL_GPL(of_led_get); void led_put(struct led_classdev *led_cdev) { module_put(led_cdev->dev->parent->driver->owner); + put_device(led_cdev->dev); } EXPORT_SYMBOL_GPL(led_put); -- cgit v1.2.3 From fafef58ef419f08bb761714a109870b617ac0bc0 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 20 Jan 2023 12:45:15 +0100 Subject: leds: led-class: Add led_module_get() helper Split out part of of_led_get() into a generic led_module_get() helper function. This is a preparation patch for adding a generic (non devicetree specific) led_get() function. Reviewed-by: Andy Shevchenko Reviewed-by: Linus Walleij Signed-off-by: Hans de Goede Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20230120114524.408368-3-hdegoede@redhat.com --- drivers/leds/led-class.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'drivers/leds') diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 7391d2cf1370..743d97b082dc 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -215,6 +215,23 @@ static int led_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); +static struct led_classdev *led_module_get(struct device *led_dev) +{ + struct led_classdev *led_cdev; + + if (!led_dev) + return ERR_PTR(-EPROBE_DEFER); + + led_cdev = dev_get_drvdata(led_dev); + + if (!try_module_get(led_cdev->dev->parent->driver->owner)) { + put_device(led_cdev->dev); + return ERR_PTR(-ENODEV); + } + + return led_cdev; +} + /** * of_led_get() - request a LED device via the LED framework * @np: device node to get the LED device from @@ -226,7 +243,6 @@ static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); struct led_classdev *of_led_get(struct device_node *np, int index) { struct device *led_dev; - struct led_classdev *led_cdev; struct device_node *led_node; led_node = of_parse_phandle(np, "leds", index); @@ -236,17 +252,7 @@ struct led_classdev *of_led_get(struct device_node *np, int index) led_dev = class_find_device_by_of_node(leds_class, led_node); of_node_put(led_node); - if (!led_dev) - return ERR_PTR(-EPROBE_DEFER); - - led_cdev = dev_get_drvdata(led_dev); - - if (!try_module_get(led_cdev->dev->parent->driver->owner)) { - put_device(led_cdev->dev); - return ERR_PTR(-ENODEV); - } - - return led_cdev; + return led_module_get(led_dev); } EXPORT_SYMBOL_GPL(of_led_get); -- cgit v1.2.3 From 537bdca2a085f524b74ac2aa83822d081c585ca6 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 20 Jan 2023 12:45:16 +0100 Subject: leds: led-class: Add __devm_led_get() helper Add a __devm_led_get() helper which registers a passed in led_classdev with devm for unregistration. This is a preparation patch for adding a generic (non devicetree specific) devm_led_get() function. Reviewed-by: Andy Shevchenko Reviewed-by: Linus Walleij Signed-off-by: Hans de Goede Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20230120114524.408368-4-hdegoede@redhat.com --- drivers/leds/led-class.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'drivers/leds') diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 743d97b082dc..4904d140a560 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -274,6 +274,22 @@ static void devm_led_release(struct device *dev, void *res) led_put(*p); } +static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led) +{ + struct led_classdev **dr; + + 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; +} + /** * devm_of_led_get - Resource-managed request of a LED device * @dev: LED consumer @@ -289,7 +305,6 @@ 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); @@ -298,17 +313,7 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev, 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; + return __devm_led_get(dev, led); } EXPORT_SYMBOL_GPL(devm_of_led_get); -- cgit v1.2.3 From abc3100fcba6827444ef4bdb17065ac3b6619dff Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 20 Jan 2023 12:45:17 +0100 Subject: leds: led-class: Add generic [devm_]led_get() Add a generic [devm_]led_get() method which can be used on both devicetree and non devicetree platforms to get a LED classdev associated with a specific function on a specific device, e.g. the privacy LED associated with a specific camera sensor. Note unlike of_led_get() this takes a string describing the function rather then an index. This is done because e.g. camera sensors might have a privacy LED, or a flash LED, or both and using an index approach leaves it unclear what the function of index 0 is if there is only 1 LED. This uses a lookup-table mechanism for non devicetree platforms. This allows the platform code to map specific LED class_dev-s to a specific device,function combinations this way. For devicetree platforms getting the LED by function-name could be made to work using the standard devicetree pattern of adding a -names string array to map names to the indexes. Reviewed-by: Linus Walleij Signed-off-by: Hans de Goede Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20230120114524.408368-5-hdegoede@redhat.com --- drivers/leds/led-class.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 21 ++++++++++++ 2 files changed, 105 insertions(+) (limited to 'drivers/leds') diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 4904d140a560..0c4b8d8d2b4f 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -23,6 +23,8 @@ #include "leds.h" static struct class *leds_class; +static DEFINE_MUTEX(leds_lookup_lock); +static LIST_HEAD(leds_lookup_list); static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -317,6 +319,88 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev, } EXPORT_SYMBOL_GPL(devm_of_led_get); +/** + * led_get() - request a LED device via the LED framework + * @dev: device for which to get the LED device + * @con_id: name of the LED from the device's point of view + * + * @return a pointer to a LED device or ERR_PTR(errno) on failure. + */ +struct led_classdev *led_get(struct device *dev, char *con_id) +{ + struct led_lookup_data *lookup; + const char *provider = NULL; + struct device *led_dev; + + mutex_lock(&leds_lookup_lock); + list_for_each_entry(lookup, &leds_lookup_list, list) { + if (!strcmp(lookup->dev_id, dev_name(dev)) && + !strcmp(lookup->con_id, con_id)) { + provider = kstrdup_const(lookup->provider, GFP_KERNEL); + break; + } + } + mutex_unlock(&leds_lookup_lock); + + if (!provider) + return ERR_PTR(-ENOENT); + + led_dev = class_find_device_by_name(leds_class, provider); + kfree_const(provider); + + return led_module_get(led_dev); +} +EXPORT_SYMBOL_GPL(led_get); + +/** + * devm_led_get() - request a LED device via the LED framework + * @dev: device for which to get the LED device + * @con_id: name of the LED from the device's point of view + * + * 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 *devm_led_get(struct device *dev, char *con_id) +{ + struct led_classdev *led; + + led = led_get(dev, con_id); + if (IS_ERR(led)) + return led; + + return __devm_led_get(dev, led); +} +EXPORT_SYMBOL_GPL(devm_led_get); + +/** + * led_add_lookup() - Add a LED lookup table entry + * @led_lookup: the lookup table entry to add + * + * Add a LED lookup table entry. On systems without devicetree the lookup table + * is used by led_get() to find LEDs. + */ +void led_add_lookup(struct led_lookup_data *led_lookup) +{ + mutex_lock(&leds_lookup_lock); + list_add_tail(&led_lookup->list, &leds_lookup_list); + mutex_unlock(&leds_lookup_lock); +} +EXPORT_SYMBOL_GPL(led_add_lookup); + +/** + * led_remove_lookup() - Remove a LED lookup table entry + * @led_lookup: the lookup table entry to remove + */ +void led_remove_lookup(struct led_lookup_data *led_lookup) +{ + mutex_lock(&leds_lookup_lock); + list_del(&led_lookup->list); + mutex_unlock(&leds_lookup_lock); +} +EXPORT_SYMBOL_GPL(led_remove_lookup); + 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..31cb74b90ffc 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -39,6 +39,21 @@ enum led_default_state { LEDS_DEFSTATE_KEEP = 2, }; +/** + * struct led_lookup_data - represents a single LED lookup entry + * + * @list: internal list of all LED lookup entries + * @provider: name of led_classdev providing the LED + * @dev_id: name of the device associated with this LED + * @con_id: name of the LED from the device's point of view + */ +struct led_lookup_data { + struct list_head list; + const char *provider; + const char *dev_id; + const char *con_id; +}; + struct led_init_data { /* device fwnode handle */ struct fwnode_handle *fwnode; @@ -211,6 +226,12 @@ void devm_led_classdev_unregister(struct device *parent, void led_classdev_suspend(struct led_classdev *led_cdev); void led_classdev_resume(struct led_classdev *led_cdev); +void led_add_lookup(struct led_lookup_data *led_lookup); +void led_remove_lookup(struct led_lookup_data *led_lookup); + +struct led_classdev *__must_check led_get(struct device *dev, char *con_id); +struct led_classdev *__must_check devm_led_get(struct device *dev, char *con_id); + 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, -- cgit v1.2.3