These new helpers simplify implementing multi-driver modules and
properly handle failure to register one driver by unregistering all
previously registered drivers.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

Each break out of the for_each_available_child_of_node loop requires
of_node_put().

This patch adds missing of_node_put() when loop breaks on conflicting
values of led-sources DT property.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>

The refcount of device_node increases after of_get_next_available_child()
is called. Make sure it is decremented also in case of DT parsing error.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>

Since brightness setting can sleep for this driver, implement
brightness_set_blocking op, instead of brightness_set.
It makes this driver compatible with LED triggers.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

Since brightness setting can sleep for this driver, implement
brightness_set_blocking op, instead of brightness_set.
It makes this driver compatible with LED triggers.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

No need to explicitly check for pointer to be null,
of_prop_next_string anyways returns NULL, if passed pointer is NULL
and hence loop will continue.
Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Acked-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

The values of BCM6328_LED_MODE_ON and BCM6328_LED_MODE_OFF were named
for active low LEDs. These should be swapped so that they are named for
the default case of active high LEDs.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

When ensuring a consistent initial LED state in bcm6328_led (as they may
be blinking instead of on/off), the LED register is set using an inverted
copy of bcm6328_led_set(). To avoid further errors relating to active low
handling, call this function directly instead.

As bcm6328_led_set() acquires the same spinlock again when updating the
register, it is called after unlocking.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
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>
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>