leds: add new lp8788 led driver

TI LP8788 PMU has the current sink as the keyboard led driver.
The brightness is controlled by the i2c commands.
Configurable parameters can be defined in the platform side.

Patch v2.
(a) use workqueue on changing the brightness

(b) use mutex_lock/unlock when the brightness is set
    and the led block of lp8788 device is enabled

(c) remove err_dev on _probe()
    : just return as returned value if any errors

(d) replace module_init/exit() with module_platform_driver()

(e) add led configuration structure and loading them by default
    if platform data is null

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index f0aaf415316d..c96bbaadeebd 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -200,6 +200,13 @@ config LEDS_LP5523
           Driver provides direct control via LED class and interface for
           programming the engines.
 
+config LEDS_LP8788
+        tristate "LED support for the TI LP8788 PMIC"
+        depends on LEDS_CLASS
+        depends on MFD_LP8788
+        help
+          This option enables support for the Keyboard LEDs on the LP8788 PMIC.
+
 config LEDS_CLEVO_MAIL
         tristate "Mail LED on Clevo notebook"
         depends on LEDS_CLASS