Create sub directory Documentation/leds and add short documentation for LP5521 and LP5523 drivers. Signed-off-by: Samu Onkalo <samu.p.onkalo@xxxxxxxxx> --- Documentation/leds/leds-lp5521.txt | 88 ++++++++++++++++++++++++++++++++++++ Documentation/leds/leds-lp5523.txt | 84 ++++++++++++++++++++++++++++++++++ 2 files changed, 172 insertions(+), 0 deletions(-) create mode 100644 Documentation/leds/leds-lp5521.txt create mode 100644 Documentation/leds/leds-lp5523.txt diff --git a/Documentation/leds/leds-lp5521.txt b/Documentation/leds/leds-lp5521.txt new file mode 100644 index 0000000..c4d8d15 --- /dev/null +++ b/Documentation/leds/leds-lp5521.txt @@ -0,0 +1,88 @@ +Kernel driver for lp5521 +======================== + +* National Semiconductor LP5521 led driver chip +* Datasheet: http://www.national.com/pf/LP/LP5521.html + +Authors: Mathias Nyman, Yuri Zaporozhets, Samu Onkalo +Contact: Samu Onkalo (samu.p.onkalo-at-nokia.com) + +Description +----------- + +LP5521 can drive up to 3 channels. Leds can be controlled directly via +the led class control interface. Channels have generic names: +lp5521:channelx, where x is 0 .. 2 + +All three channels can be also controlled using the engine micro programs. +More details of the instructions can be found from the public data sheet. + +Control interface for the engines: +x is 1 .. 3 +enginex_mode : disabled, load, run +enginex_load : store program (visible only in engine load mode) + +Example (start to blink the channel 2 led): +cd /sys/class/leds/lp5521:channel2/device +echo "load" > engine3_mode +echo "037f4d0003ff6000" > engine3_load +echo "run" > engine3_mode + +stop the engine: +echo "disabled" > engine3_mode + +sysfs contains a selftest entry. +The test communicates with the chip and checks that +the clock mode is automatically set to the requested one. + +Each channel has its own led current settings. +/sys/class/leds/lp5521:channel0/led_current - RW +/sys/class/leds/lp5521:channel0/max_current - RO +Format: 10x mA i.e 10 means 1.0 mA + +example platform data: + +Note: chan_nr can have values between 0 and 2. + +static struct lp5521_led_config lp5521_led_config[] = { + { + .chan_nr = 0, + .led_current = 50, + .max_current = 130, + }, { + .chan_nr = 1, + .led_current = 0, + .max_current = 130, + }, { + .chan_nr = 2, + .led_current = 0, + .max_current = 130, + } +}; + +static int lp5521_setup(void) +{ + /* setup HW resources */ +} + +static void lp5521_release(void) +{ + /* Release HW resources */ +} + +static void lp5521_enable(bool state) +{ + /* Control of chip enable signal */ +} + +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, + .setup_resources = lp5521_setup, + .release_resources = lp5521_release, + .enable = lp5521_enable, +}; + +If the current is set to 0 in the platform data, that channel is +disabled and it is not visible in the sysfs. diff --git a/Documentation/leds/leds-lp5523.txt b/Documentation/leds/leds-lp5523.txt new file mode 100644 index 0000000..265758d --- /dev/null +++ b/Documentation/leds/leds-lp5523.txt @@ -0,0 +1,84 @@ +Kernel driver for lp5523 +======================== + +* National Semiconductor LP5523 led driver chip +* Datasheet: http://www.national.com/pf/LP/LP5523.html + +Authors: Mathias Nyman, Yuri Zaporozhets, Samu Onkalo +Contact: Samu Onkalo (samu.p.onkalo-at-nokia.com) + +Description +----------- +LP5523 can drive up to 9 channels. Leds can be controlled directly via +the led class control interface. Channels have generic names: +lp5523:channelx where x is 0...8 + +The chip provides 3 engines. Each engine can control channels without +interaction from the main CPU. Details of the micro engine code can be found +from the public data sheet. Leds can be muxed to different channels. + +Control interface for the engines: +x is 1 .. 3 +enginex_mode : disabled, load, run +enginex_load : microcode load (visible only in load mode) +enginex_leds : led mux control (visible only in load mode) + +cd /sys/class/leds/lp5523:channel2/device +echo "load" > engine3_mode +echo "9d80400004ff05ff437f0000" > engine3_load +echo "111111111" > engine3_leds +echo "run" > engine3_mode + +sysfs contains a selftest entry. It measures each channel +voltage level and checks if it looks reasonable. If the level is too high, +the led is missing; if the level is too low, there is a short circuit. + +Selftest uses always the current from the platform data. + +Each channel contains led current settings. +/sys/class/leds/lp5523:channel2/led_current - RW +/sys/class/leds/lp5523:channel2/max_current - RO +Format: 10x mA i.e 10 means 1.0 mA + +Example platform data: + +Note - chan_nr can have values between 0 and 8. + +static struct lp5523_led_config lp5523_led_config[] = { + { + .chan_nr = 0, + .led_current = 50, + .max_current = 130, + }, +... + }, { + .chan_nr = 8, + .led_current = 50, + .max_current = 130, + } +}; + +static int lp5523_setup(void) +{ + /* Setup HW resources */ +} + +static void lp5523_release(void) +{ + /* Release HW resources */ +} + +static void lp5523_enable(bool state) +{ + /* Control chip enable signal */ +} + +static struct lp5523_platform_data lp5523_platform_data = { + .led_config = lp5523_led_config, + .num_channels = ARRAY_SIZE(lp5523_led_config), + .clock_mode = LP5523_CLOCK_EXT, + .setup_resources = lp5523_setup, + .release_resources = lp5523_release, + .enable = lp5523_enable, +}; + -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
