leds: add new LP5562 LED driver

LP5562 can drive up to 4 channels, RGB and White.
LEDs can be controlled directly via the led class control interface.

 LP55xx common driver
  LP5562 is one of LP55xx family device, so LP55xx common code are used.
  On the other hand, chip specific configuration is defined in the structure
  'lp55xx_device_config'

 LED pattern data
  LP5562 has also internal program memory which is used for running various LED
  patterns. LP5562 driver supports the firmware interface and the predefined
  pattern data as well.

 LP5562 device attributes: 'led_pattern' and 'engine_mux'
  A 'led_pattern' is an index code which runs the predefined pattern data.
  And 'engine_mux' is updated with the firmware interface is activated.
  Detailed description has been updated in the documentation files,
  'leds-lp55xx.txt' and 'leds-lp5562.txt'.

 Changes on the header file
  LP5562 configurable definitions are added.
  Pattern RGB data is fixed as constant value.
  (No side effect on other devices, LP5521 or LP5523.)

(cooloney@gmail.com: remove redundant mutex_unlock(). Reported by Dan
Carpenter <dan.carpenter@oracle.com>)

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 135 insertions, 0 deletions

diff --git a/Documentation/leds/leds-lp5562.txt b/Documentation/leds/leds-lp5562.txt
new file mode 100644
index 000000000000..96061000dd93
--- /dev/null
+++ b/Documentation/leds/leds-lp5562.txt
@@ -0,0 +1,135 @@
+Kernel driver for LP5562
+========================
+
+* TI LP5562 LED Driver
+
+Author: Milo(Woogyom) Kim <milo.kim@ti.com>
+
+Description
+
+  LP5562 can drive up to 4 channels. R/G/B and White.
+  LEDs can be controlled directly via the led class control interface.
+
+  All four channels can be also controlled using the engine micro programs.
+  LP5562 has the internal program memory for running various LED patterns.
+  For the details, please refer to 'firmware' section in leds-lp55xx.txt
+
+Device attribute: engine_mux
+
+  3 Engines are allocated in LP5562, but the number of channel is 4.
+  Therefore each channel should be mapped to the engine number.
+  Value : RGB or W
+
+  This attribute is used for programming LED data with the firmware interface.
+  Unlike the LP5521/LP5523/55231, LP5562 has unique feature for the engine mux,
+  so additional sysfs is required.
+
+  LED Map
+  Red   ... Engine 1 (fixed)
+  Green ... Engine 2 (fixed)
+  Blue  ... Engine 3 (fixed)
+  White ... Engine 1 or 2 or 3 (selective)
+
+How to load the program data using engine_mux
+
+  Before loading the LP5562 program data, engine_mux should be written between
+  the engine selection and loading the firmware.
+  Engine mux has two different mode, RGB and W.
+  RGB is used for loading RGB program data, W is used for W program data.
+
+  For example, run blinking green channel pattern,
+  echo 2 > /sys/bus/i2c/devices/xxxx/select_engine     # 2 is for green channel
+  echo "RGB" > /sys/bus/i2c/devices/xxxx/engine_mux    # engine mux for RGB
+  echo 1 > /sys/class/firmware/lp5562/loading
+  echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
+  echo 0 > /sys/class/firmware/lp5562/loading
+  echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
+
+  To run a blinking white pattern,
+  echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine
+  echo "W" > /sys/bus/i2c/devices/xxxx/engine_mux
+  echo 1 > /sys/class/firmware/lp5562/loading
+  echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
+  echo 0 > /sys/class/firmware/lp5562/loading
+  echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
+
+How to load the predefined patterns
+
+  Please refer to 'leds-lp55xx.txt"
+
+Setting Current of Each Channel
+
+  Like LP5521 and LP5523/55231, LP5562 provides LED current settings.
+  The 'led_current' and 'max_current' are used.
+
+(Example of Platform data)
+
+To configure the platform specific data, lp55xx_platform_data structure is used.
+
+static struct lp55xx_led_config lp5562_led_config[] = {
+        {
+                .name           = "R",
+                .chan_nr        = 0,
+                .led_current    = 20,
+                .max_current    = 40,
+        },
+        {
+                .name           = "G",
+                .chan_nr        = 1,
+                .led_current    = 20,
+                .max_current    = 40,
+        },
+        {
+                .name           = "B",
+                .chan_nr        = 2,
+                .led_current    = 20,
+                .max_current    = 40,
+        },
+        {
+                .name           = "W",
+                .chan_nr        = 3,
+                .led_current    = 20,
+                .max_current    = 40,
+        },
+};
+
+static int lp5562_setup(void)
+{
+        /* setup HW resources */
+}
+
+static void lp5562_release(void)
+{
+        /* Release HW resources */
+}
+
+static void lp5562_enable(bool state)
+{
+        /* Control of chip enable signal */
+}
+
+static struct lp55xx_platform_data lp5562_platform_data = {
+        .led_config     = lp5562_led_config,
+        .num_channels   = ARRAY_SIZE(lp5562_led_config),
+        .setup_resources   = lp5562_setup,
+        .release_resources = lp5562_release,
+        .enable            = lp5562_enable,
+};
+
+If the current is set to 0 in the platform data, that channel is
+disabled and it is not visible in the sysfs.
+
+The 'update_config' : CONFIG register (ADDR 08h)
+This value is platform-specific data.
+If update_config is not defined, the CONFIG register is set with
+'LP5562_PWRSAVE_EN | LP5562_CLK_AUTO'.
+(Enable auto-powersave, set automatic clock source selection)
+
+#define LP5562_CONFIGS  (LP5562_PWM_HF | LP5562_PWRSAVE_EN | \
+                         LP5562_CLK_SRC_EXT)
+
+static struct lp55xx_platform_data lp5562_pdata = {
+        .led_config = lp5562_led_config,
+        .num_channels = ARRAY_SIZE(lp5562_led_config),
+        .update_config = LP5562_CONFIGS,
+};