[media] doc-rst: add documentation for si4713

Convert it to ReST and add it to the media/v4l-drivers book.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/v4l-drivers/si4713.rst

-Driver for I2C radios for the Silicon Labs Si4713 FM Radio Transmitters
+.. include:: <isonum.txt>
+
+The Silicon Labs Si4713 FM Radio Transmitter Driver
+===================================================
+
+Copyright |copy| 2009 Nokia Corporation
 
-Copyright (c) 2009 Nokia Corporation
 Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
 
 
 Information about the Device
-============================
+----------------------------
+
 This chip is a Silicon Labs product. It is a I2C device, currently on 0x63 address.
 Basically, it has transmission and signal noise level measurement features.
 
@@ -19,7 +24,8 @@ properties which can change the behavior of this chip.
 Users must comply with local regulations on radio frequency (RF) transmission.
 
 Device driver description
-=========================
+-------------------------
+
 There are two modules to handle this device. One is a I2C device driver
 and the other is a platform driver.
 
@@ -37,140 +43,148 @@ etc. But mostly of its properties will be present in the extended controls.
 When the v4l2 mute property is set to 1 (true), the driver will turn the chip off.
 
 Properties description
-======================
+----------------------
 
 The properties can be accessed using v4l2 extended controls.
 Here is an output from v4l2-ctl util:
-/ # v4l2-ctl -d /dev/radio0 --all -L
-Driver Info:
-	Driver name   : radio-si4713
-	Card type     : Silicon Labs Si4713 Modulator
-	Bus info      :
-	Driver version: 0
-	Capabilities  : 0x00080800
-		RDS Output
-		Modulator
-Audio output: 0 (FM Modulator Audio Out)
-Frequency: 1408000 (88.000000 MHz)
-Video Standard = 0x00000000
-Modulator:
-	Name                 : FM Modulator
-	Capabilities         : 62.5 Hz stereo rds
-	Frequency range      : 76.0 MHz - 108.0 MHz
-	Subchannel modulation: stereo+rds
-
-User Controls
-
-			   mute (bool) : default=1 value=0
-
-FM Radio Modulator Controls
-
-	   rds_signal_deviation (int)  : min=0 max=90000 step=10 default=200 value=200 flags=slider
-		 rds_program_id (int)  : min=0 max=65535 step=1 default=0 value=0
-	       rds_program_type (int)  : min=0 max=31 step=1 default=0 value=0
-		    rds_ps_name (str)  : min=0 max=96 step=8 value='si4713  '
-		 rds_radio_text (str)  : min=0 max=384 step=32 value=''
-  audio_limiter_feature_enabled (bool) : default=1 value=1
-     audio_limiter_release_time (int)  : min=250 max=102390 step=50 default=5010 value=5010 flags=slider
-	audio_limiter_deviation (int)  : min=0 max=90000 step=10 default=66250 value=66250 flags=slider
-audio_compression_feature_enabl (bool) : default=1 value=1
-	 audio_compression_gain (int)  : min=0 max=20 step=1 default=15 value=15 flags=slider
-    audio_compression_threshold (int)  : min=-40 max=0 step=1 default=-40 value=-40 flags=slider
-  audio_compression_attack_time (int)  : min=0 max=5000 step=500 default=0 value=0 flags=slider
- audio_compression_release_time (int)  : min=100000 max=1000000 step=100000 default=1000000 value=1000000 flags=slider
-     pilot_tone_feature_enabled (bool) : default=1 value=1
-	   pilot_tone_deviation (int)  : min=0 max=90000 step=10 default=6750 value=6750 flags=slider
-	   pilot_tone_frequency (int)  : min=0 max=19000 step=1 default=19000 value=19000 flags=slider
-	  pre_emphasis_settings (menu) : min=0 max=2 default=1 value=1
-	       tune_power_level (int)  : min=0 max=120 step=1 default=88 value=88 flags=slider
-	 tune_antenna_capacitor (int)  : min=0 max=191 step=1 default=0 value=110 flags=slider
-/ #
+
+.. code-block:: none
+
+	/ # v4l2-ctl -d /dev/radio0 --all -L
+	Driver Info:
+		Driver name   : radio-si4713
+		Card type     : Silicon Labs Si4713 Modulator
+		Bus info      :
+		Driver version: 0
+		Capabilities  : 0x00080800
+			RDS Output
+			Modulator
+	Audio output: 0 (FM Modulator Audio Out)
+	Frequency: 1408000 (88.000000 MHz)
+	Video Standard = 0x00000000
+	Modulator:
+		Name                 : FM Modulator
+		Capabilities         : 62.5 Hz stereo rds
+		Frequency range      : 76.0 MHz - 108.0 MHz
+		Subchannel modulation: stereo+rds
+
+	User Controls
+
+				mute (bool) : default=1 value=0
+
+	FM Radio Modulator Controls
+
+		rds_signal_deviation (int)  : min=0 max=90000 step=10 default=200 value=200 flags=slider
+			rds_program_id (int)  : min=0 max=65535 step=1 default=0 value=0
+		rds_program_type (int)  : min=0 max=31 step=1 default=0 value=0
+			rds_ps_name (str)  : min=0 max=96 step=8 value='si4713  '
+			rds_radio_text (str)  : min=0 max=384 step=32 value=''
+	audio_limiter_feature_enabled (bool) : default=1 value=1
+	audio_limiter_release_time (int)  : min=250 max=102390 step=50 default=5010 value=5010 flags=slider
+		audio_limiter_deviation (int)  : min=0 max=90000 step=10 default=66250 value=66250 flags=slider
+	audio_compression_feature_enabl (bool) : default=1 value=1
+		audio_compression_gain (int)  : min=0 max=20 step=1 default=15 value=15 flags=slider
+	audio_compression_threshold (int)  : min=-40 max=0 step=1 default=-40 value=-40 flags=slider
+	audio_compression_attack_time (int)  : min=0 max=5000 step=500 default=0 value=0 flags=slider
+	audio_compression_release_time (int)  : min=100000 max=1000000 step=100000 default=1000000 value=1000000 flags=slider
+	pilot_tone_feature_enabled (bool) : default=1 value=1
+		pilot_tone_deviation (int)  : min=0 max=90000 step=10 default=6750 value=6750 flags=slider
+		pilot_tone_frequency (int)  : min=0 max=19000 step=1 default=19000 value=19000 flags=slider
+		pre_emphasis_settings (menu) : min=0 max=2 default=1 value=1
+		tune_power_level (int)  : min=0 max=120 step=1 default=88 value=88 flags=slider
+		tune_antenna_capacitor (int)  : min=0 max=191 step=1 default=0 value=110 flags=slider
 
 Here is a summary of them:
 
 * Pilot is an audible tone sent by the device.
 
-pilot_frequency - Configures the frequency of the stereo pilot tone.
-pilot_deviation - Configures pilot tone frequency deviation level.
-pilot_enabled - Enables or disables the pilot tone feature.
+- pilot_frequency - Configures the frequency of the stereo pilot tone.
+- pilot_deviation - Configures pilot tone frequency deviation level.
+- pilot_enabled - Enables or disables the pilot tone feature.
 
-* The si4713 device is capable of applying audio compression to the transmitted signal.
+* The si4713 device is capable of applying audio compression to the
+  transmitted signal.
 
-acomp_enabled - Enables or disables the audio dynamic range control feature.
-acomp_gain - Sets the gain for audio dynamic range control.
-acomp_threshold - Sets the threshold level for audio dynamic range control.
-acomp_attack_time - Sets the attack time for audio dynamic range control.
-acomp_release_time - Sets the release time for audio dynamic range control.
+- acomp_enabled - Enables or disables the audio dynamic range control feature.
+- acomp_gain - Sets the gain for audio dynamic range control.
+- acomp_threshold - Sets the threshold level for audio dynamic range control.
+- acomp_attack_time - Sets the attack time for audio dynamic range control.
+- acomp_release_time - Sets the release time for audio dynamic range control.
 
 * Limiter setups audio deviation limiter feature. Once a over deviation occurs,
-it is possible to adjust the front-end gain of the audio input and always
-prevent over deviation.
+  it is possible to adjust the front-end gain of the audio input and always
+  prevent over deviation.
 
-limiter_enabled - Enables or disables the limiter feature.
-limiter_deviation - Configures audio frequency deviation level.
-limiter_release_time - Sets the limiter release time.
+- limiter_enabled - Enables or disables the limiter feature.
+- limiter_deviation - Configures audio frequency deviation level.
+- limiter_release_time - Sets the limiter release time.
 
 * Tuning power
 
-power_level - Sets the output power level for signal transmission.
-antenna_capacitor - This selects the value of antenna tuning capacitor manually
-or automatically if set to zero.
+- power_level - Sets the output power level for signal transmission.
+  antenna_capacitor - This selects the value of antenna tuning capacitor
+  manually or automatically if set to zero.
 
 * RDS related
 
-rds_ps_name - Sets the RDS ps name field for transmission.
-rds_radio_text - Sets the RDS radio text for transmission.
-rds_pi - Sets the RDS PI field for transmission.
-rds_pty - Sets the RDS PTY field for transmission.
+- rds_ps_name - Sets the RDS ps name field for transmission.
+- rds_radio_text - Sets the RDS radio text for transmission.
+- rds_pi - Sets the RDS PI field for transmission.
+- rds_pty - Sets the RDS PTY field for transmission.
 
 * Region related
 
-preemphasis - sets the preemphasis to be applied for transmission.
+- preemphasis - sets the preemphasis to be applied for transmission.
 
 RNL
-===
+---
 
 This device also has an interface to measure received noise level. To do that, you should
 ioctl the device node. Here is an code of example:
 
-int main (int argc, char *argv[])
-{
-	struct si4713_rnl rnl;
-	int fd = open("/dev/radio0", O_RDWR);
-	int rval;
+.. code-block:: none
+
+	int main (int argc, char *argv[])
+	{
+		struct si4713_rnl rnl;
+		int fd = open("/dev/radio0", O_RDWR);
+		int rval;
 
-	if (argc < 2)
-		return -EINVAL;
+		if (argc < 2)
+			return -EINVAL;
 
-	if (fd < 0)
-		return fd;
+		if (fd < 0)
+			return fd;
 
-	sscanf(argv[1], "%d", &rnl.frequency);
+		sscanf(argv[1], "%d", &rnl.frequency);
 
-	rval = ioctl(fd, SI4713_IOC_MEASURE_RNL, &rnl);
-	if (rval < 0)
-		return rval;
+		rval = ioctl(fd, SI4713_IOC_MEASURE_RNL, &rnl);
+		if (rval < 0)
+			return rval;
 
-	printf("received noise level: %d\n", rnl.rnl);
+		printf("received noise level: %d\n", rnl.rnl);
 
-	close(fd);
-}
+		close(fd);
+	}
 
 The struct si4713_rnl and SI4713_IOC_MEASURE_RNL are defined under
 include/linux/platform_data/media/si4713.h.
 
 Stereo/Mono and RDS subchannels
-===============================
+-------------------------------
 
 The device can also be configured using the available sub channels for
 transmission. To do that use S/G_MODULATOR ioctl and configure txsubchans properly.
 Refer to the V4L2 API specification for proper use of this ioctl.
 
 Testing
-=======
+-------
 Testing is usually done with v4l2-ctl utility for managing FM tuner cards.
 The tool can be found in v4l-dvb repository under v4l2-apps/util directory.
 
 Example for setting rds ps name:
-# v4l2-ctl -d /dev/radio0 --set-ctrl=rds_ps_name="Dummy"
+
+.. code-block:: none
+
+	# v4l2-ctl -d /dev/radio0 --set-ctrl=rds_ps_name="Dummy"