Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Tested-by: Simon Guinot <simon.guinot@sequanux.org>

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Workqueue, 'set_brightness_work' is used for scheduling brightness control.
This workqueue is canceled when the LED class device is unregistered.
Currently, LED subsystem handles like below.

  cancel_work_sync(&led_cdev->set_brightness_work)
  led_set_brightness(led_cdev, LED_OFF)

However, this could be a problem.
Workqueue is going to be canceled but LED device needs to be off.
The worst case is null pointer access due to scheduling a workqueue.

LED module is loaded.
  LED driver private data is allocated by using devm_zalloc().

LED module is unloaded.
  led_classdev_unregister() is called.
    cancel_work_sync()
      led_set_brightness(led_cdev, LED_OFF)
        schedule_work() if LED driver uses brightness_set_blocking()
        In the meantime, driver private data will be freed.

        ..scheduling..

        brightness_set_blocking() callback is invoked.
          For the brightness control, LED driver tries to access private
          data but resource is removed!

To avoid this problem, LED subsystem should turn off the brightness first
and wait for completion.

  led_set_brightness(led_cdev, LED_OFF)
  flush_work(&led_cdev->set_brightness_work)

It guarantees that LED driver turns off the brightness prior to
resource management.

Cc: linux-leds@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Strobe state variable is declared as unsigned long, remove
the check for values less than zero then.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Reported-by: David Binderman <dcb314@hotmail.com>

The refcount of device_node increases after of_node_get() is called.
So, a break out of the loop requires of_node_put().

This patch adds missing of_node_put() when loop breaks.
Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Some PWMs are disabled by default or the default pin setting
does not match the LED_OFF state (e.g., active-low leds).
Hence, the driver may end up reporting 0 brightness, but
the leds are actually on using full brightness, because
it never enforces its default configuration.
So enforce it by calling led_pwm_set() after successfully
registering the device.

Tested on a Phytec phyFLEX i.MX6Q board based on kernel
v3.19.5.
Signed-off-by: Markus Hofstaetter <markus.hofstaetter@ait.ac.at>
Tested-by: Markus Hofstaetter <markus.hofstaetter@ait.ac.at>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

The header of this file fixes the license to GPL 2 only without the
option to use later version. So use the string "GPL v2" that is to be
used in this case.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

The transient trigger duration is documented to be in msec units, but is
actually in jiffies units. Other time based triggers are in msec units
as well. Fix the timer setup to convert from msec.

This could break an existing userspace that worked around this problem,
but exposing jiffies to userspace is just wrong and would break anyway
if HZ is changed.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Daniel Jeong <daniel.jeong@ti.com>
Cc: G.Shark Jeong <gshark.jeong@gmail.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Raphael Assenat <raph@8d.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Raphael Assenat <raph@8d.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Antonio Ospite <ao2@ao2.it>
Reviewed-by: Mark Brown <broonie@kernel.org>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Work queues are not used in this driver, so remove the include.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Dan Murphy <dmurphy@ti.com>
Cc: Ricardo Ribalda <ricardo.ribalda@gmail.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Nate Case <ncase@xes-inc.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Milo Kim <milo.kim@ti.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Milo Kim <milo.kim@ti.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Daniel Jeong <daniel.jeong@ti.com>
Cc: G.Shark Jeong <gshark.jeong@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Johan Hovold <johan@kernel.org>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Jan-Simon Moeller <dl9pf@gmx.de>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Kim Kyuwon <q1.kim@samsung.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Now the core implements the work queue, remove it from the driver,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

LED subsystem shifted responsibility for choosing between SYNC or ASYNC
way of setting brightness from drivers to the caller. Adapt the wrapper
to those changes.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: linux-media@vger.kernel.org
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Ingi Kim <ingi2.kim@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>

Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>

This patch adds description of the LED subsystem API for
setting an LED brightness.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

This patch removes SET_BRIGHTNESS_ASYNC and SET_BRIGHTNESS_SYNC flags.
led_set_brightness() now calls led_set_brightness_nosleep() instead of
choosing between sync and async op basing on the flags defined by the
driver.

From now on, if a user wants to make sure that brightness will be set
synchronously, they have to use led_set_brightness_sync() API. It is now
being made publicly available since it has become apparent that it is
a caller who should decide whether brightness is to be set in
a synchronous or an asynchronous way.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>