Merge tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg...

[karo-tx-linux.git] / Documentation / leds / leds-lp5521.txt

diff --git a/Documentation/leds/leds-lp5521.txt b/Documentation/leds/leds-lp5521.txt
index f48ab757d12079d51eee0a39ef5ec16a891cfa5f..0e542ab3d4a0f0d21cf915672c0686bf105a2e23 100644 (file)
--- a/Documentation/leds/leds-lp5521.txt
+++ b/Documentation/leds/leds-lp5521.txt
@@ -92,3 +92,60 @@ static struct lp5521_platform_data lp5521_platform_data = {
 
 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
+'LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT'.
+(Enable auto-powersave, set charge pump to auto, red to battery)
+
+example of update_config :
+
+#define LP5521_CONFIGS (LP5521_PWM_HF | LP5521_PWRSAVE_EN | \
+                       LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT | \
+                       LP5521_CLK_INT)
+
+static struct lp5521_platform_data lp5521_pdata = {
+       .led_config = lp5521_led_config,
+       .num_channels = ARRAY_SIZE(lp5521_led_config),
+       .clock_mode = LP5521_CLOCK_INT,
+       .update_config = LP5521_CONFIGS,
+};
+
+LED patterns : LP5521 has autonomous operation without external control.
+Pattern data can be defined in the platform data.
+
+example of led pattern data :
+
+/* RGB(50,5,0) 500ms on, 500ms off, infinite loop */
+static u8 pattern_red[] = {
+               0x40, 0x32, 0x60, 0x00, 0x40, 0x00, 0x60, 0x00,
+               };
+
+static u8 pattern_green[] = {
+               0x40, 0x05, 0x60, 0x00, 0x40, 0x00, 0x60, 0x00,
+               };
+
+static struct lp5521_led_pattern board_led_patterns[] = {
+       {
+               .r = pattern_red,
+               .g = pattern_green,
+               .size_r = ARRAY_SIZE(pattern_red),
+               .size_g = ARRAY_SIZE(pattern_green),
+       },
+};
+
+static struct lp5521_platform_data lp5521_platform_data = {
+        .led_config     = lp5521_led_config,
+        .num_channels   = ARRAY_SIZE(lp5521_led_config),
+        .clock_mode     = LP5521_CLOCK_EXT,
+       .patterns = board_led_patterns,
+       .num_patterns = ARRAY_SIZE(board_led_patterns),
+};
+
+Then predefined led pattern(s) can be executed via the sysfs.
+To start the pattern #1,
+# echo 1 > /sys/bus/i2c/devices/xxxx/led_pattern
+(xxxx : i2c bus & slave address)
+To end the pattern,
+# echo 0 > /sys/bus/i2c/devices/xxxx/led_pattern