docs: leds: convert to ReST

Rename the leds documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

1 files changed, 115 insertions, 0 deletions

diff --git a/Documentation/leds/leds-lp5521.rst b/Documentation/leds/leds-lp5521.rst
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index 000000000000..0432615b083d
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+++ b/Documentation/leds/leds-lp5521.rst
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+========================
+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.
+
+LP5521 has the internal program memory for running various LED patterns.
+There are two ways to run LED patterns.
+
+1) Legacy interface - enginex_mode and enginex_load
+   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
+
+  To stop the engine::
+
+	echo "disabled" > engine3_mode
+
+2) Firmware interface - LP55xx common interface
+
+For the details, please refer to 'firmware' section in leds-lp55xx.txt
+
+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::
+
+  static struct lp55xx_led_config lp5521_led_config[] = {
+	  {
+		.name = "red",
+		  .chan_nr        = 0,
+		  .led_current    = 50,
+		.max_current    = 130,
+	  }, {
+		.name = "green",
+		  .chan_nr        = 1,
+		  .led_current    = 0,
+		.max_current    = 130,
+	  }, {
+		.name = "blue",
+		  .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 lp55xx_platform_data lp5521_platform_data = {
+	  .led_config     = lp5521_led_config,
+	  .num_channels   = ARRAY_SIZE(lp5521_led_config),
+	  .clock_mode     = LP55XX_CLOCK_EXT,
+	  .setup_resources   = lp5521_setup,
+	  .release_resources = lp5521_release,
+	  .enable            = lp5521_enable,
+  };
+
+Note:
+  chan_nr can have values between 0 and 2.
+  The name of each channel can be configurable.
+  If the name field is not defined, the default name will be set to 'xxxx:channelN'
+  (XXXX : pdata->label or i2c client name, N : channel number)
+
+
+If the current is set to 0 in the platform data, that channel is
+disabled and it is not visible in the sysfs.