Currently we use the `linux,default-trigger` device tree property of a LED to define the default trigger which should be activated for a LED.
But the LED device tree binding also documents the `trigger-sources` property, which specifies the source device which should be triggering the LED. The `trigger-sources` property is currently implemented only in drivers/usb/core/ledtrig-usbport.c. Lets add a method to struct led_trigger which, if implemented, can check whether this trigger should be enabled as default. This check shall be done by checking whether the specified `trigger-sources` refers to a device compatible with the trigger. For this two new helper functions, of_led_count_trigger_sources and of_led_get_trigger_source, are implemented. Signed-off-by: Marek Behún <[email protected]> Cc: Rob Herring <[email protected]> Cc: [email protected] --- drivers/leds/led-triggers.c | 68 ++++++++++++++++++++++++++++++++----- include/linux/leds.h | 25 ++++++++++++++ 2 files changed, 85 insertions(+), 8 deletions(-) diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c index 91da90cfb11d9..a93c1b6a94282 100644 --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -243,18 +243,30 @@ void led_trigger_remove(struct led_classdev *led_cdev) } EXPORT_SYMBOL_GPL(led_trigger_remove); +static bool trigger_is_default(struct led_classdev *led_cdev, + struct led_trigger *trig) +{ + if (!trigger_relevant(led_cdev, trig)) + return false; + + if (led_cdev->default_trigger && + !strcmp(led_cdev->default_trigger, trig->name)) + return true; + + if (trig->has_valid_source && trig->has_valid_source(led_cdev)) + return true; + + return false; +} + void led_trigger_set_default(struct led_classdev *led_cdev) { struct led_trigger *trig; - if (!led_cdev->default_trigger) - return; - down_read(&triggers_list_lock); down_write(&led_cdev->trigger_lock); list_for_each_entry(trig, &trigger_list, next_trig) { - if (!strcmp(led_cdev->default_trigger, trig->name) && - trigger_relevant(led_cdev, trig)) { + if (trigger_is_default(led_cdev, trig)) { led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER; led_trigger_set(led_cdev, trig); break; @@ -306,9 +318,7 @@ int led_trigger_register(struct led_trigger *trig) down_read(&leds_list_lock); list_for_each_entry(led_cdev, &leds_list, node) { down_write(&led_cdev->trigger_lock); - if (!led_cdev->trigger && led_cdev->default_trigger && - !strcmp(led_cdev->default_trigger, trig->name) && - trigger_relevant(led_cdev, trig)) { + if (!led_cdev->trigger && trigger_is_default(led_cdev, trig)) { led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER; led_trigger_set(led_cdev, trig); } @@ -459,3 +469,45 @@ void led_trigger_unregister_simple(struct led_trigger *trig) kfree(trig); } EXPORT_SYMBOL_GPL(led_trigger_unregister_simple); + +int of_led_count_trigger_sources(struct led_classdev *led_cdev) +{ + struct device_node *np; + int count; + + np = dev_of_node(led_cdev->dev); + if (!np) + return 0; + + count = of_count_phandle_with_args(np, "trigger-sources", + "#trigger-source-cells"); + if (count == -ENOENT) + return 0; + else if (count < 0) + dev_warn(led_cdev->dev, + "Failed parsing trigger sources for %pOF!\n", np); + + return count; +} +EXPORT_SYMBOL_GPL(of_led_count_trigger_sources); + +int of_led_get_trigger_source(struct led_classdev *led_cdev, int index, + struct of_phandle_args *args) +{ + struct device_node *np; + int err; + + np = dev_of_node(led_cdev->dev); + if (!np) + return -ENOENT; + + err = of_parse_phandle_with_args(np, "trigger-sources", + "#trigger-source-cells", index, args); + if (err < 0 && err != -ENOENT) + dev_warn(led_cdev->dev, + "Failed parsing trigger source index %i for %pOF!\n", + index, np); + + return err; +} +EXPORT_SYMBOL_GPL(of_led_get_trigger_source); diff --git a/include/linux/leds.h b/include/linux/leds.h index 6a8d6409c993e..c03e0a4e0e45d 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -13,6 +13,7 @@ #include <linux/kernfs.h> #include <linux/list.h> #include <linux/mutex.h> +#include <linux/of.h> #include <linux/rwsem.h> #include <linux/spinlock.h> #include <linux/timer.h> @@ -352,6 +353,14 @@ struct led_trigger { int (*activate)(struct led_classdev *led_cdev); void (*deactivate)(struct led_classdev *led_cdev); + /* + * Check whether LED has defined valid source for this trigger. + * If yes, this trigger should be set as default trigger for LED. + * This should use of_led_count_trigger_sources and + * of_led_get_trigger_source functions. + */ + bool (*has_valid_source)(struct led_classdev *led_cdev); + /* LED-private triggers have this set */ struct led_hw_trigger_type *trigger_type; @@ -394,6 +403,10 @@ void led_trigger_set_default(struct led_classdev *led_cdev); int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger); void led_trigger_remove(struct led_classdev *led_cdev); +int of_led_count_trigger_sources(struct led_classdev *led_cdev); +int of_led_get_trigger_source(struct led_classdev *led_cdev, int index, + struct of_phandle_args *args); + static inline void led_set_trigger_data(struct led_classdev *led_cdev, void *trigger_data) { @@ -452,6 +465,18 @@ static inline int led_trigger_set(struct led_classdev *led_cdev, } static inline void led_trigger_remove(struct led_classdev *led_cdev) {} + +static inline int of_led_count_trigger_sources(struct led_classdev *led_cdev) +{ + return 0; +} +static inline int of_led_get_trigger_source(struct led_classdev *led_cdev, + int index, + struct of_phandle_args *args) +{ + return -EOPNOTSUPP; +} + static inline void led_set_trigger_data(struct led_classdev *led_cdev) {} static inline void *led_get_trigger_data(struct led_classdev *led_cdev) { -- 2.26.2
