Re: [PATCH -next 1/2] leds: add /sys/devices/virtual/led-trigger/
On Thu, Oct 03, 2019 at 12:13:00AM +0900, Akinobu Mita wrote: > Reading /sys/class/leds//trigger returns all available LED triggers. > However, this violates the "one value per file" rule of sysfs. > > This makes led_triggers "real" devices and provides an > /sys/devices/virtual/led-trigger/ directory that contains a sub-directoriy > for each LED trigger device. The name of the sub-directory matches the LED > trigger name. > > We can find all available LED triggers by listing this directory contents. > > Cc: Greg Kroah-Hartman > Cc: "Rafael J. Wysocki" > Cc: Jacek Anaszewski > Cc: Pavel Machek > Cc: Dan Murphy > Signed-off-by: Akinobu Mita > --- > .../ABI/testing/sysfs-devices-virtual-led-trigger | 8 +++ > drivers/leds/led-triggers.c| 57 > ++ > include/linux/leds.h | 3 ++ > 3 files changed, 68 insertions(+) > create mode 100644 > Documentation/ABI/testing/sysfs-devices-virtual-led-trigger > > diff --git a/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger > b/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger > new file mode 100644 > index 000..b8eb8f3 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger > @@ -0,0 +1,8 @@ > +What:/sys/devices/virtual/leds-trigger/ > +Date:September 2019 > +KernelVersion: 5.5 > +Contact: linux-l...@vger.kernel.org > +Description: > + This directory contains a sub-directoriy for each LED trigger "directoriy"? > + device. The name of the sub-directory matches the LED trigger > + name. You are just creating directories here, and doing nothing with them, why? That seems kind of pointless. thanks, greg k-h
Re: [PATCH -next 1/2] leds: add /sys/devices/virtual/led-trigger/
On Thu, Oct 03, 2019 at 12:13:00AM +0900, Akinobu Mita wrote:
> Reading /sys/class/leds//trigger returns all available LED triggers.
> However, this violates the "one value per file" rule of sysfs.
>
> This makes led_triggers "real" devices and provides an
> /sys/devices/virtual/led-trigger/ directory that contains a sub-directoriy
> for each LED trigger device. The name of the sub-directory matches the LED
> trigger name.
>
> We can find all available LED triggers by listing this directory contents.
>
> Cc: Greg Kroah-Hartman
> Cc: "Rafael J. Wysocki"
> Cc: Jacek Anaszewski
> Cc: Pavel Machek
> Cc: Dan Murphy
> Signed-off-by: Akinobu Mita
> ---
> .../ABI/testing/sysfs-devices-virtual-led-trigger | 8 +++
> drivers/leds/led-triggers.c| 57
> ++
> include/linux/leds.h | 3 ++
> 3 files changed, 68 insertions(+)
> create mode 100644
> Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
>
> diff --git a/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
> b/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
> new file mode 100644
> index 000..b8eb8f3
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
> @@ -0,0 +1,8 @@
> +What:/sys/devices/virtual/leds-trigger/
> +Date:September 2019
> +KernelVersion: 5.5
> +Contact: linux-l...@vger.kernel.org
> +Description:
> + This directory contains a sub-directoriy for each LED trigger
> + device. The name of the sub-directory matches the LED trigger
> + name.
> diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
> index 79e30d2..0b810cf 100644
> --- a/drivers/leds/led-triggers.c
> +++ b/drivers/leds/led-triggers.c
> @@ -267,21 +267,76 @@ void led_trigger_rename_static(const char *name, struct
> led_trigger *trig)
> }
> EXPORT_SYMBOL_GPL(led_trigger_rename_static);
>
> +struct ledtrig_device {
> + struct device dev;
> +};
> +
> +static void ledtrig_device_release(struct device *dev)
> +{
> + struct ledtrig_device *trig_dev =
> + container_of(dev, struct ledtrig_device, dev);
> +
> + kfree(trig_dev);
> +}
> +
> +static struct bus_type led_trigger_subsys = {
> + .name = "led-trigger",
> +};
> +
> +static int led_trigger_subsys_init(void)
> +{
> + static DEFINE_MUTEX(init_mutex);
> + static bool init_done;
> + int ret = 0;
> +
> + mutex_lock(_mutex);
> + if (!init_done) {
a test and set of an atomic would solve the issue of having both a mutex
and a boolean, right?
thanks,
greg k-h
[PATCH -next 1/2] leds: add /sys/devices/virtual/led-trigger/
Reading /sys/class/leds//trigger returns all available LED triggers.
However, this violates the "one value per file" rule of sysfs.
This makes led_triggers "real" devices and provides an
/sys/devices/virtual/led-trigger/ directory that contains a sub-directoriy
for each LED trigger device. The name of the sub-directory matches the LED
trigger name.
We can find all available LED triggers by listing this directory contents.
Cc: Greg Kroah-Hartman
Cc: "Rafael J. Wysocki"
Cc: Jacek Anaszewski
Cc: Pavel Machek
Cc: Dan Murphy
Signed-off-by: Akinobu Mita
---
.../ABI/testing/sysfs-devices-virtual-led-trigger | 8 +++
drivers/leds/led-triggers.c| 57 ++
include/linux/leds.h | 3 ++
3 files changed, 68 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
diff --git a/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
b/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
new file mode 100644
index 000..b8eb8f3
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-virtual-led-trigger
@@ -0,0 +1,8 @@
+What: /sys/devices/virtual/leds-trigger/
+Date: September 2019
+KernelVersion: 5.5
+Contact: linux-l...@vger.kernel.org
+Description:
+ This directory contains a sub-directoriy for each LED trigger
+ device. The name of the sub-directory matches the LED trigger
+ name.
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 79e30d2..0b810cf 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -267,21 +267,76 @@ void led_trigger_rename_static(const char *name, struct
led_trigger *trig)
}
EXPORT_SYMBOL_GPL(led_trigger_rename_static);
+struct ledtrig_device {
+ struct device dev;
+};
+
+static void ledtrig_device_release(struct device *dev)
+{
+ struct ledtrig_device *trig_dev =
+ container_of(dev, struct ledtrig_device, dev);
+
+ kfree(trig_dev);
+}
+
+static struct bus_type led_trigger_subsys = {
+ .name = "led-trigger",
+};
+
+static int led_trigger_subsys_init(void)
+{
+ static DEFINE_MUTEX(init_mutex);
+ static bool init_done;
+ int ret = 0;
+
+ mutex_lock(_mutex);
+ if (!init_done) {
+ ret = subsys_virtual_register(_trigger_subsys, NULL);
+ if (!ret)
+ init_done = true;
+ }
+ mutex_unlock(_mutex);
+
+ return ret;
+}
+
/* LED Trigger Interface */
int led_trigger_register(struct led_trigger *trig)
{
struct led_classdev *led_cdev;
struct led_trigger *_trig;
+ struct ledtrig_device *trig_dev;
+ int ret;
rwlock_init(>leddev_list_lock);
INIT_LIST_HEAD(>led_cdevs);
+ ret = led_trigger_subsys_init();
+ if (ret)
+ return ret;
+ trig_dev = kzalloc(sizeof(*trig_dev), GFP_KERNEL);
+ if (!trig_dev)
+ return -ENOMEM;
+
+ trig_dev->dev.bus = _trigger_subsys;
+ trig_dev->dev.release = ledtrig_device_release;
+ dev_set_name(_dev->dev, "%s", trig->name);
+
+ ret = device_register(_dev->dev);
+ if (ret) {
+ put_device(_dev->dev);
+ return ret;
+ }
+
+ trig->trig_dev = trig_dev;
+
down_write(_list_lock);
/* Make sure the trigger's name isn't already in use */
list_for_each_entry(_trig, _list, next_trig) {
if (!strcmp(_trig->name, trig->name)) {
up_write(_list_lock);
+ device_unregister(_dev->dev);
return -EEXIST;
}
}
@@ -327,6 +382,8 @@ void led_trigger_unregister(struct led_trigger *trig)
up_write(_cdev->trigger_lock);
}
up_read(_list_lock);
+
+ device_unregister(>trig_dev->dev);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index da78b27..d63c8e7 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -336,6 +336,8 @@ static inline bool led_sysfs_is_disabled(struct
led_classdev *led_cdev)
#define TRIG_NAME_MAX 50
+struct ledtrig_device;
+
struct led_trigger {
/* Trigger Properties */
const char *name;
@@ -350,6 +352,7 @@ struct led_trigger {
struct list_head next_trig;
const struct attribute_group **groups;
+ struct ledtrig_device *trig_dev;
};
/*
--
2.7.4
