backlight: lp855x_bl: support new LP8555 device

LP8555 is one of the LP855x family devices.

This device needs pre_init_device() and post_init_device() driver
structure.  It's same as LP8557, so the device configuration code is
shared with LP8557.  Backlight outputs are generated from dual DC-DC boost
converters.  It's configurable EPROM settings which are defined in the
platform data.

Driver documentation and device tree bindings are updated.

Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/platform_data/lp855x.h b/include/linux/platform_data/lp855x.h
index ea3200527dd3..1b2ba24e4e03 100644
--- a/include/linux/platform_data/lp855x.h
+++ b/include/linux/platform_data/lp855x.h
@@ -40,6 +40,17 @@
 #define LP8553_PWM_CONFIG       LP8550_PWM_CONFIG
 #define LP8553_I2C_CONFIG       LP8550_I2C_CONFIG
 
+/* CONFIG register - LP8555 */
+#define LP8555_PWM_STANDBY      BIT(7)
+#define LP8555_PWM_FILTER       BIT(6)
+#define LP8555_RELOAD_EPROM     BIT(3)  /* use it if EPROMs should be reset
+                                           when the backlight turns on */
+#define LP8555_OFF_OPENLEDS     BIT(2)
+#define LP8555_PWM_CONFIG       LP8555_PWM_ONLY
+#define LP8555_I2C_CONFIG       LP8555_I2C_ONLY
+#define LP8555_COMB1_CONFIG     LP8555_COMBINED1
+#define LP8555_COMB2_CONFIG     LP8555_COMBINED2
+
 /* DEVICE CONTROL register - LP8556 */
 #define LP8556_PWM_CONFIG       (LP8556_PWM_ONLY << BRT_MODE_SHFT)
 #define LP8556_COMB1_CONFIG     (LP8556_COMBINED1 << BRT_MODE_SHFT)
@@ -65,6 +76,7 @@ enum lp855x_chip_id {
         LP8551,
         LP8552,
         LP8553,
+        LP8555,
         LP8556,
         LP8557,
 };
@@ -89,6 +101,13 @@ enum lp8553_brighntess_source {
         LP8553_I2C_ONLY = LP8550_I2C_ONLY,
 };
 
+enum lp8555_brightness_source {
+        LP8555_PWM_ONLY,
+        LP8555_I2C_ONLY,
+        LP8555_COMBINED1,       /* Brightness register with shaped PWM */
+        LP8555_COMBINED2,       /* PWM with shaped brightness register */
+};
+
 enum lp8556_brightness_source {
         LP8556_PWM_ONLY,
         LP8556_COMBINED1,       /* pwm + i2c before the shaper block */