Move led_stop_software_blink() code into led_brightness_set() to ensure
software blink timer is stopped and cleared when changing trigger.

Also use led_set_brightness() instead of calling
led_cdev->brightness_set() directly to keep led_cdev->brightness
consistent with current LED status.

This ensure proper cleaning when changing triggers, as without this fix
a LED may be turned off while leaving it's led_cdev->brightness = 1,
leading to an erratic software-blink behaviour.

The problem was easy to reproduce by changing the trigger from "timer"
to "oneshot".
Signed-off-by: NFabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: NBryan Wu <bryan.wu@canonical.com>

Add two new functions, led_blink_set_oneshot and
led_trigger_blink_oneshot, to be used by triggers for one-shot blink of
led devices.

This is implemented extending the existing software-blink code, and uses
the same timer and handler function.

The behavior of the code is to do a blink-on, blink-off sequence when
the function is called, ignoring other calls until the sequence is
completed so that the leds keep blinking at constant rate if the
functions are called repeatedly.

This is meant to be used by drivers which needs to trigger on sporadic
event, but doesn't have clear busy/idle trigger points.

After the blink sequence the led remains off. This behavior can be
inverted setting the "invert" argument, which blink the led off, than on
and leave the led on after the sequence.

(bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking
when writing the same value to delay_on or delay_off')
Signed-off-by: NFabio Baltieri <fabio.baltieri@gmail.com>
Acked-by: NShuah Khan <shuahkhan@gmail.com>
Signed-off-by: NBryan Wu <bryan.wu@canonical.com>

Function led_set_software_blink() assumes that blink timer is still running,
but commit 488bc35b introduced disabling
of blink timer before each call to led_set_software_blink().

Correct led_software_blink():
1) remove protection against reprogramming blink timer to the same values,
   because it only disables blinking now,
2) remove unnecessary call to led_stop_software_blink().
Signed-off-by: NRafal Prylowski <prylowski@metasoft.pl>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NBryan Wu <bryan.wu@canonical.com>

After moving some core functions to led-core.c, led-class.c can be built
as module again.
Signed-off-by: NBryan Wu <bryan.wu@canonical.com>
Acked-by: NRichard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Break the lines which were more than 80 characters into more
lines; replace SPACEs with TABs; correct ident at switch-case;
change character encoding from ISO-8859-2 to UTF-8.

The order of the functions in led-triggers.c changed in order
the similar functions can still be together under titles
"Used by LED Class", "LED Trigger Interface" and "Simple
LED Tigger Interface" as was grouped before when exported
with EXPORT_SYMBOL.
Signed-off-by: NMárton Németh <nm127@freemail.hu>
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

Covert leds_list_lock to a rw_sempahore to match previous LED trigger
locking fixes, fixing lock ordering.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

locking init cleanups:

 - convert " = SPIN_LOCK_UNLOCKED" to spin_lock_init() or DEFINE_SPINLOCK()
 - convert rwlocks in a similar manner

this patch was generated automatically.

Motivation:

 - cleanliness
 - lockdep needs control of lock initialization, which the open-coded
   variants do not give
 - it's also useful for -rt and for lock debugging in general
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add the foundations of a new LEDs subsystem.  This patch adds a class which
presents LED devices within sysfs and allows their brightness to be
controlled.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>