merge: http://www.linuxtv.org/hg/~hverkuil/v4l-dvb-rds

From: Mauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

15 files changed, 288 insertions, 102 deletions

diff --git a/linux/drivers/media/radio/radio-cadet.c b/linux/drivers/media/radio/radio-cadet.c
index 2fd4aae2e..99551d836 100644
--- a/linux/drivers/media/radio/radio-cadet.c
+++ b/linux/drivers/media/radio/radio-cadet.c
@@ -386,7 +386,8 @@ static int vidioc_querycap(struct file *file, void *priv,
 	strlcpy(v->card, "ADS Cadet", sizeof(v->card));
 	strlcpy(v->bus_info, "ISA", sizeof(v->bus_info));
 	v->version = CADET_VERSION;
-	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_READWRITE;
+	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO |
+			  V4L2_CAP_READWRITE | V4L2_CAP_RDS_CAPTURE;
 	return 0;
 }
 
@@ -399,7 +400,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
 	switch (v->index) {
 	case 0:
 		strlcpy(v->name, "FM", sizeof(v->name));
-		v->capability = V4L2_TUNER_CAP_STEREO;
+		v->capability = V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_RDS;
 		v->rangelow = 1400;     /* 87.5 MHz */
 		v->rangehigh = 1728;    /* 108.0 MHz */
 		v->rxsubchans = cadet_getstereo(dev);
@@ -413,6 +414,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
 		default:
 			break;
 		}
+		v->rxsubchans |= V4L2_TUNER_SUB_RDS;
 		break;
 	case 1:
 		strlcpy(v->name, "AM", sizeof(v->name));
diff --git a/linux/drivers/media/radio/radio-si470x.c b/linux/drivers/media/radio/radio-si470x.c
index 20aa447cc..3efd397d1 100644
--- a/linux/drivers/media/radio/radio-si470x.c
+++ b/linux/drivers/media/radio/radio-si470x.c
@@ -1254,7 +1254,7 @@ static int si470x_vidioc_querycap(struct file *file, void *priv,
 	usb_make_path(radio->usbdev, capability->bus_info, sizeof(capability->bus_info));
 	capability->version = DRIVER_KERNEL_VERSION;
 	capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
-		V4L2_CAP_TUNER | V4L2_CAP_RADIO;
+		V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
 
 	return 0;
 }
@@ -1413,7 +1413,8 @@ static int si470x_vidioc_g_tuner(struct file *file, void *priv,
 	/* driver constants */
 	strcpy(tuner->name, "FM");
 	tuner->type = V4L2_TUNER_RADIO;
-	tuner->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
+	tuner->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
+			    V4L2_TUNER_CAP_RDS;
 
 	/* range limits */
 	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_BAND) >> 6) {
@@ -1439,6 +1440,10 @@ static int si470x_vidioc_g_tuner(struct file *file, void *priv,
 		tuner->rxsubchans = V4L2_TUNER_SUB_MONO;
 	else
 		tuner->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
+	/* If there is a reliable method of detecting an RDS channel,
+	   then this code should check for that before setting this
+	   RDS subchannel. */
+	tuner->rxsubchans |= V4L2_TUNER_SUB_RDS;
 
 	/* mono/stereo selector */
 	if ((radio->registers[POWERCFG] & POWERCFG_MONO) == 0)
diff --git a/linux/drivers/media/video/bt8xx/bttv-driver.c b/linux/drivers/media/video/bt8xx/bttv-driver.c
index bd5dde3f8..9c25efe06 100644
--- a/linux/drivers/media/video/bt8xx/bttv-driver.c
+++ b/linux/drivers/media/video/bt8xx/bttv-driver.c
@@ -2679,6 +2679,8 @@ static int bttv_querycap(struct file *file, void  *priv,
 		V4L2_CAP_VBI_CAPTURE |
 		V4L2_CAP_READWRITE |
 		V4L2_CAP_STREAMING;
+	if (btv->has_saa6588)
+		cap->capabilities |= V4L2_CAP_RDS_CAPTURE;
 	if (no_overlay <= 0)
 		cap->capabilities |= V4L2_CAP_VIDEO_OVERLAY;
 
diff --git a/linux/drivers/media/video/saa6588.c b/linux/drivers/media/video/saa6588.c
index 58aff8305..dcc83511e 100644
--- a/linux/drivers/media/video/saa6588.c
+++ b/linux/drivers/media/video/saa6588.c
@@ -51,7 +51,7 @@ I2C_CLIENT_INSMOD;
 /* insmod options */
 static unsigned int debug;
 static unsigned int xtal;
-static unsigned int rbds;
+static unsigned int mmbs;
 static unsigned int plvl;
 static unsigned int bufblocks = 100;
 
@@ -59,8 +59,8 @@ module_param(debug, int, 0644);
 MODULE_PARM_DESC(debug, "enable debug messages");
 module_param(xtal, int, 0);
 MODULE_PARM_DESC(xtal, "select oscillator frequency (0..3), default 0");
-module_param(rbds, int, 0);
-MODULE_PARM_DESC(rbds, "select mode, 0=RDS, 1=RBDS, default 0");
+module_param(mmbs, int, 0);
+MODULE_PARM_DESC(mmbs, "enable MMBS mode: 0=off (default), 1=on");
 module_param(plvl, int, 0);
 MODULE_PARM_DESC(plvl, "select pause level (0..3), default 0");
 module_param(bufblocks, int, 0);
@@ -89,6 +89,7 @@ struct saa6588 {
 	unsigned char last_blocknum;
 	wait_queue_head_t read_queue;
 	int data_available_for_read;
+	u8 sync;
 };
 
 static inline struct saa6588 *to_saa6588(struct v4l2_subdev *sd)
@@ -272,13 +273,16 @@ static void saa6588_i2c_poll(struct saa6588 *s)
 	unsigned char tmp;
 
 	/* Although we only need 3 bytes, we have to read at least 6.
-	   SAA6588 returns garbage otherwise */
+	   SAA6588 returns garbage otherwise. */
 	if (6 != i2c_master_recv(client, &tmpbuf[0], 6)) {
 		if (debug > 1)
 			dprintk(PREFIX "read error!\n");
 		return;
 	}
 
+	s->sync = tmpbuf[0] & 0x10;
+	if (!s->sync)
+		return;
 	blocknum = tmpbuf[0] >> 5;
 	if (blocknum == s->last_blocknum) {
 		if (debug > 3)
@@ -297,9 +301,8 @@ static void saa6588_i2c_poll(struct saa6588 *s)
 	   occurred during reception of this block.
 	   Bit 6: Corrected bit. Indicates that an error was
 	   corrected for this data block.
-	   Bits 5-3: Received Offset. Indicates the offset received
-	   by the sync system.
-	   Bits 2-0: Offset Name. Indicates the offset applied to this data.
+	   Bits 5-3: Same as bits 0-2.
+	   Bits 2-0: Block number.
 
 	   SAA6588 byte order is Status-MSB-LSB, so we have to swap the
 	   first and the last of the 3 bytes block.
@@ -309,12 +312,21 @@ static void saa6588_i2c_poll(struct saa6588 *s)
 	tmpbuf[2] = tmpbuf[0];
 	tmpbuf[0] = tmp;
 
+	/* Map 'Invalid block E' to 'Invalid Block' */
+	if (blocknum == 6)
+		blocknum = V4L2_RDS_BLOCK_INVALID;
+	/* And if are not in mmbs mode, then 'Block E' is also mapped
+	   to 'Invalid Block'. As far as I can tell MMBS is discontinued,
+	   and if there is ever a need to support E blocks, then please
+	   contact the linux-media mailinglist. */
+	else if (!mmbs && blocknum == 5)
+		blocknum = V4L2_RDS_BLOCK_INVALID;
 	tmp = blocknum;
 	tmp |= blocknum << 3;	/* Received offset == Offset Name (OK ?) */
 	if ((tmpbuf[2] & 0x03) == 0x03)
-		tmp |= 0x80;	/* uncorrectable error */
+		tmp |= V4L2_RDS_BLOCK_ERROR;	 /* uncorrectable error */
 	else if ((tmpbuf[2] & 0x03) != 0x00)
-		tmp |= 0x40;	/* corrected error */
+		tmp |= V4L2_RDS_BLOCK_CORRECTED; /* corrected error */
 	tmpbuf[2] = tmp;	/* Is this enough ? Should we also check other bits ? */
 
 	spin_lock_irqsave(&s->lock, flags);
@@ -340,14 +352,14 @@ static void saa6588_work(struct work_struct *work)
 	schedule_delayed_work(&s->work, msecs_to_jiffies(20));
 }
 
-static int saa6588_configure(struct saa6588 *s)
+static void saa6588_configure(struct saa6588 *s)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&s->sd);
 	unsigned char buf[3];
 	int rc;
 
 	buf[0] = cSyncRestart;
-	if (rbds)
+	if (mmbs)
 		buf[0] |= cProcessingModeRBDS;
 
 	buf[1] = cFlywheelDefault;
@@ -393,8 +405,6 @@ static int saa6588_configure(struct saa6588 *s)
 	rc = i2c_master_send(client, buf, 3);
 	if (rc != 3)
 		printk(PREFIX "i2c i/o error: rc == %d (should be 3)\n", rc);
-
-	return 0;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -435,6 +445,24 @@ static long saa6588_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
 	return 0;
 }
 
+static int saa6588_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
+{
+	struct saa6588 *s = to_saa6588(sd);
+
+	vt->capability |= V4L2_TUNER_CAP_RDS;
+	if (s->sync)
+		vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
+	return 0;
+}
+
+static int saa6588_s_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
+{
+	struct saa6588 *s = to_saa6588(sd);
+
+	saa6588_configure(s);
+	return 0;
+}
+
 static int saa6588_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -449,8 +477,14 @@ static const struct v4l2_subdev_core_ops saa6588_core_ops = {
 	.ioctl = saa6588_ioctl,
 };
 
+static const struct v4l2_subdev_tuner_ops saa6588_tuner_ops = {
+	.g_tuner = saa6588_g_tuner,
+	.s_tuner = saa6588_s_tuner,
+};
+
 static const struct v4l2_subdev_ops saa6588_ops = {
 	.core = &saa6588_core_ops,
+	.tuner = &saa6588_tuner_ops,
 };
 
 /* ---------------------------------------------------------------------- */
diff --git a/linux/drivers/media/video/saa7134/saa7134-core.c b/linux/drivers/media/video/saa7134/saa7134-core.c
index da73430ad..e466afd18 100644
--- a/linux/drivers/media/video/saa7134/saa7134-core.c
+++ b/linux/drivers/media/video/saa7134/saa7134-core.c
@@ -1073,8 +1073,10 @@ static int __devinit saa7134_initdev(struct pci_dev *pci_dev,
 		sd = v4l2_i2c_new_probed_subdev_addr(&dev->v4l2_dev,
 				&dev->i2c_adap,	"saa6588", "saa6588",
 				saa7134_boards[dev->board].rds_addr);
-		if (sd)
+		if (sd) {
 			printk(KERN_INFO "%s: found RDS decoder\n", dev->name);
+			dev->has_rds = 1;
+		}
 	}
 
 	request_submodules(dev);
diff --git a/linux/drivers/media/video/saa7134/saa7134-video.c b/linux/drivers/media/video/saa7134/saa7134-video.c
index e7f78fcb8..5be072c57 100644
--- a/linux/drivers/media/video/saa7134/saa7134-video.c
+++ b/linux/drivers/media/video/saa7134/saa7134-video.c
@@ -1826,6 +1826,8 @@ static int saa7134_querycap(struct file *file, void  *priv,
 		V4L2_CAP_READWRITE |
 		V4L2_CAP_STREAMING |
 		V4L2_CAP_TUNER;
+	if (dev->has_rds)
+		cap->capabilities |= V4L2_CAP_RDS_CAPTURE;
 	if (saa7134_no_overlay <= 0)
 		cap->capabilities |= V4L2_CAP_VIDEO_OVERLAY;
 
diff --git a/linux/drivers/media/video/saa7134/saa7134.h b/linux/drivers/media/video/saa7134/saa7134.h
index 454802e73..be5abf059 100644
--- a/linux/drivers/media/video/saa7134/saa7134.h
+++ b/linux/drivers/media/video/saa7134/saa7134.h
@@ -544,6 +544,7 @@ struct saa7134_dev {
 	struct i2c_adapter         i2c_adap;
 	struct i2c_client          i2c_client;
 	unsigned char              eedata[256];
+	int 			   has_rds;
 
 	/* video overlay */
 	struct v4l2_framebuffer    ovbuf;
diff --git a/linux/include/linux/videodev2.h b/linux/include/linux/videodev2.h
index ee6458f74..b5c4f7295 100644
--- a/linux/include/linux/videodev2.h
+++ b/linux/include/linux/videodev2.h
@@ -1185,6 +1185,7 @@ struct v4l2_modulator {
 #define V4L2_TUNER_CAP_LANG2		0x0020
 #define V4L2_TUNER_CAP_SAP		0x0020
 #define V4L2_TUNER_CAP_LANG1		0x0040
+#define V4L2_TUNER_CAP_RDS		0x0080
 
 /*  Flags for the 'rxsubchans' field */
 #define V4L2_TUNER_SUB_MONO		0x0001
@@ -1192,6 +1193,7 @@ struct v4l2_modulator {
 #define V4L2_TUNER_SUB_LANG2		0x0004
 #define V4L2_TUNER_SUB_SAP		0x0004
 #define V4L2_TUNER_SUB_LANG1		0x0008
+#define V4L2_TUNER_SUB_RDS		0x0010
 
 /*  Values for the 'audmode' field */
 #define V4L2_TUNER_MODE_MONO		0x0000
@@ -1217,6 +1219,27 @@ struct v4l2_hw_freq_seek {
 };
 
 /*
+ *	R D S
+ */
+
+struct v4l2_rds_data {
+	__u8 	lsb;
+	__u8 	msb;
+	__u8 	block;
+} __attribute__ ((packed));
+
+#define V4L2_RDS_BLOCK_MSK 	 0x7
+#define V4L2_RDS_BLOCK_A 	 0
+#define V4L2_RDS_BLOCK_B 	 1
+#define V4L2_RDS_BLOCK_C 	 2
+#define V4L2_RDS_BLOCK_D 	 3
+#define V4L2_RDS_BLOCK_C_ALT 	 4
+#define V4L2_RDS_BLOCK_INVALID 	 7
+
+#define V4L2_RDS_BLOCK_CORRECTED 0x40
+#define V4L2_RDS_BLOCK_ERROR 	 0x80
+
+/*
  *	A U D I O
  */
 struct v4l2_audio {
diff --git a/v4l2-apps/util/v4l2-ctl.cpp b/v4l2-apps/util/v4l2-ctl.cpp
index 309e14312..6f6b5e2f8 100644
--- a/v4l2-apps/util/v4l2-ctl.cpp
+++ b/v4l2-apps/util/v4l2-ctl.cpp
@@ -956,6 +956,8 @@ static std::string rxsubchans2s(int rxsubchans)
 		s += "lang1 ";
 	if (rxsubchans & V4L2_TUNER_SUB_LANG2)
 		s += "lang2 ";
+	if (rxsubchans & V4L2_TUNER_SUB_RDS)
+		s += "rds ";
 	return s;
 }
 
@@ -990,6 +992,8 @@ static std::string tcap2s(unsigned cap)
 		s += "lang1 ";
 	if (cap & V4L2_TUNER_CAP_LANG2)
 		s += "lang2 ";
+	if (cap & V4L2_TUNER_CAP_RDS)
+		s += "rds ";
 	return s;
 }
 
diff --git a/v4l2-spec/biblio.sgml b/v4l2-spec/biblio.sgml
index b013ece1d..afc8a0dd2 100644
--- a/v4l2-spec/biblio.sgml
+++ b/v4l2-spec/biblio.sgml
@@ -158,54 +158,23 @@ Signal - NTSC for Studio Applications"</title>
 1125-Line High-Definition Production"</title>
     </biblioentry>
 
-    <biblioentry id="v4l">
-      <abbrev>V4L</abbrev>
-      <authorgroup>
-	<author>
-	  <firstname>Alan</firstname>
-	  <surname>Cox</surname>
-	  <affiliation>
-	    <orgname>Red Hat, Inc.</orgname>
-	    <address>
-	      <email>alan@redhat.com</email>
-	    </address>
-	  </affiliation>
-	</author>
-      </authorgroup>
-      <title>Video4Linux API Specification</title>
-      <abstract>
-	<para>This file is part of the Linux kernel sources under
-<filename>Documentation/video4linux</filename>.</para>
-      </abstract>
-    </biblioentry>
-
-    <biblioentry id="v4lprog">
-      <abbrev>V4LPROG</abbrev>
-      <authorgroup>
-	<author>
-	  <firstname>Alan</firstname>
-	  <surname>Cox</surname>
-	  <affiliation>
-	    <orgname>Red Hat, Inc.</orgname>
-	    <address>
-	      <email>alan@redhat.com</email>
-	    </address>
-	  </affiliation>
-	</author>
-      </authorgroup>
-      <title>Video4Linux Programming (a.k.a. The Video4Linux
-Book)</title>
-      <abstract>
-	<para>About V4L <emphasis>driver</emphasis> programming. This
-book is part of the Linux kernel DocBook documentation, for example at
-<ulink url="http://kernelnewbies.org/documents/">
-http://kernelnewbies.org/documents/</ulink>. SGML sources are included
-in the kernel sources.</para>
-      </abstract>
-      <copyright>
-	<year>2000</year>
-	<holder>Alan Cox</holder>
-      </copyright>
+    <biblioentry id="en50067">
+      <abbrev>EN&nbsp;50067</abbrev>
+      <authorgroup>
+	<corpauthor>European Committee for Electrotechnical Standardization
+(<ulink url="http://www.cenelec.eu">http://www.cenelec.eu</ulink>)</corpauthor>
+      </authorgroup>
+      <title>Specification of the radio data system (RDS) for VHF/FM sound broadcasting
+in the frequency range from 87,5 to 108,0 MHz</title>
+    </biblioentry>
+
+    <biblioentry id="nrsc4">
+      <abbrev>NRSC-4</abbrev>
+      <authorgroup>
+	<corpauthor>National Radio Systems Committee
+(<ulink url="http://www.nrscstandards.org">http://www.nrscstandards.org</ulink>)</corpauthor>
+      </authorgroup>
+      <title>NTSC-4: United States RBDS Standard</title>
     </biblioentry>
 
   </bibliography>
diff --git a/v4l2-spec/compat.sgml b/v4l2-spec/compat.sgml
index 94713023d..c1c725f35 100644
--- a/v4l2-spec/compat.sgml
+++ b/v4l2-spec/compat.sgml
@@ -1273,9 +1273,8 @@ also the size of the structure changed, which is encoded in the ioctl
 request code, thus older V4L2 devices will respond with an &EINVAL; to
 the new &VIDIOC-QUERYCAP; ioctl.</para>
 
-	  <para>There are new fields to identify the driver, a new (as
-of yet unspecified) device function
-<constant>V4L2_CAP_RDS_CAPTURE</constant>, the
+	  <para>There are new fields to identify the driver, a new RDS
+device function <constant>V4L2_CAP_RDS_CAPTURE</constant>, the
 <constant>V4L2_CAP_AUDIO</constant> flag indicates if the device has
 any audio connectors, another I/O capability
 <constant>V4L2_CAP_ASYNCIO</constant> can be flagged. In response to
@@ -2294,6 +2293,15 @@ was renamed to <structname id=v4l2-chip-ident-old>v4l2_chip_ident_old</structnam
 	</listitem>
        </orderedlist>
      </section>
+    <section>
+      <title>V4L2 in Linux 2.6.32</title>
+      <orderedlist>
+	<listitem>
+	  <para>Finalized the RDS capture API. See <xref linkend="rds"> for
+more information.</para>
+	</listitem>
+       </orderedlist>
+     </section>
    </section>
 
    <section id="other">
diff --git a/v4l2-spec/dev-rds.sgml b/v4l2-spec/dev-rds.sgml
index 07bfd4c65..8f357d9f0 100644
--- a/v4l2-spec/dev-rds.sgml
+++ b/v4l2-spec/dev-rds.sgml
@@ -2,38 +2,154 @@
 
       <para>The Radio Data System transmits supplementary
 information in binary format, for example the station name or travel
-information, on a inaudible audio subcarrier of a radio program. This
-interface aims at devices capable of receiving and decoding RDS
+information, on an inaudible audio subcarrier of a radio program. This
+interface is aimed at devices capable of receiving and decoding RDS
 information.</para>
 
-      <para>The V4L API defines its RDS API as follows.</para>
-
-      <para>From radio devices supporting it, RDS data can be read
-with the &func-read; function. The data is packed in groups of three,
-as follows:<orderedlist>
-      <listitem>
-	<para>First Octet Least Significant Byte of RDS Block</para>
-      </listitem>
-      <listitem>
-	<para>Second Octet Most Significant Byte of RDS Block</para>
-      </listitem>
-      <listitem>
-	<para>Third Octet Bit 7: Error bit. Indicates that an
-uncorrectable error occurred during reception of this block. Bit 6:
-Corrected bit. Indicates that an error was corrected for this data
-block. Bits 5-3: Received Offset. Indicates the offset received by the
-sync system. Bits 2-0: Offset Name. Indicates the offset applied to
-this data.</para>
-      </listitem>
-	</orderedlist></para>
-
-      <para>It was argued <!-- video4linux-list@redhat.com
-on 12 Nov 2002, subject "RDS/RBDS" --> the RDS API should be
-extended before integration into V4L2, no new API has been devised yet.
-Please write to the linux-media mailing list for discussion: &v4l-ml;.
-Meanwhile no V4L2 driver should set the
-<constant>V4L2_CAP_RDS_CAPTURE</constant> capability flag.</para>
+      <para>For more information see the core RDS standard <xref linkend="en50067">
+and the RBDS standard <xref linkend="nrsc4">.</para>
 
+      <para>Note that the RBDS standard as is used in the USA is almost identical
+to the RDS standard. Any RDS decoder can also handle RBDS. Only some of the fields
+have slightly different meanings. See the RBDS standard for more information.</para>
+
+      <para>The RBDS standard also specifies support for MMBS (Modified Mobile Search).
+This is a proprietary format which seems to be discontinued. The RDS interface does not
+support this format. Should support for MMBS (or the so-called 'E blocks' in general)
+be needed, then please contact the linux-media mailing list: &v4l-ml;.</para>
+
+  <section>
+    <title>Querying Capabilities</title>
+
+    <para>Devices supporting the RDS capturing API
+set the <constant>V4L2_CAP_RDS_CAPTURE</constant> flag in
+the <structfield>capabilities</structfield> field of &v4l2-capability;
+returned by the &VIDIOC-QUERYCAP; ioctl.</para>
+
+    <para>Any tuner that supports RDS will set the
+<constant>V4L2_TUNER_CAP_RDS</constant> flag in the <structfield>capability</structfield>
+field of &v4l2-tuner;.</para>
+
+    <para>Whether an RDS signal is present can be detected by looking at
+the <structfield>rxsubchans</structfield> field of &v4l2-tuner;: the
+<constant>V4L2_TUNER_SUB_RDS</constant> will be set if RDS data was detected.</para>
+
+  </section>
+
+  <section>
+    <title>Reading RDS data</title>
+
+      <para>RDS data can be read from the radio device
+with the &func-read; function. The data is packed in groups of three bytes,
+as follows:</para>
+    <table frame="none" pgwide="1" id="v4l2-rds-data">
+      <title>struct
+<structname>v4l2_rds_data</structname></title>
+      <tgroup cols="3">
+	<colspec colname="c1" colwidth="1*">
+	<colspec colname="c2" colwidth="1*">
+	<colspec colname="c3" colwidth="5*">
+	<tbody valign="top">
+	  <row>
+	    <entry>__u8</entry>
+	    <entry><structfield>lsb</structfield></entry>
+	    <entry>Least Significant Byte of RDS Block</entry>
+	  </row>
+	  <row>
+	    <entry>__u8</entry>
+	    <entry><structfield>msb</structfield></entry>
+	    <entry>Most Significant Byte of RDS Block</entry>
+	  </row>
+	  <row>
+	    <entry>__u8</entry>
+	    <entry><structfield>block</structfield></entry>
+	    <entry>Block description</entry>
+	  </row>
+	</tbody>
+      </tgroup>
+    </table>
+    <table frame="none" pgwide="1" id="v4l2-rds-block">
+      <title>Block description</title>
+      <tgroup cols="2">
+	<colspec colname="c1" colwidth="1*">
+	<colspec colname="c2" colwidth="5*">
+	<tbody valign="top">
+	  <row>
+	    <entry>Bits 0-2</entry>
+	    <entry>Block (aka offset) of the received data.</entry>
+	  </row>
+	  <row>
+	    <entry>Bits 3-5</entry>
+	    <entry>Deprecated. Currently identical to bits 0-2. Do not use these bits.</entry>
+	  </row>
+	  <row>
+	    <entry>Bit 6</entry>
+	    <entry>Corrected bit. Indicates that an error was corrected for this data block.</entry>
+	  </row>
+	  <row>
+	    <entry>Bit 7</entry>
+	    <entry>Error bit. Indicates that an uncorrectable error occurred during reception of this block.</entry>
+	  </row>
+	</tbody>
+      </tgroup>
+    </table>
+
+    <table frame="none" pgwide="1" id="v4l2-rds-block-codes">
+      <title>Block defines</title>
+      <tgroup cols="3">
+	<colspec colname="c1" colwidth="1*">
+	<colspec colname="c2" colwidth="1*">
+	<colspec colname="c3" colwidth="5*">
+	<tbody valign="top">
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_MSK</entry>
+	    <entry>7</entry>
+	    <entry>Mask for bits 0-2 to get the block ID.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_A</entry>
+	    <entry>0</entry>
+	    <entry>Block A.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_B</entry>
+	    <entry>1</entry>
+	    <entry>Block B.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_C</entry>
+	    <entry>2</entry>
+	    <entry>Block C.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_D</entry>
+	    <entry>3</entry>
+	    <entry>Block D.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_C_ALT</entry>
+	    <entry>4</entry>
+	    <entry>Block C'.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_INVALID</entry>
+	    <entry>7</entry>
+	    <entry>An invalid block.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_CORRECTED</entry>
+	    <entry>0x40</entry>
+	    <entry>A bit error was detected but corrected.</entry>
+	  </row>
+	  <row>
+	    <entry>V4L2_RDS_BLOCK_ERROR</entry>
+	    <entry>0x80</entry>
+	    <entry>An incorrectable error occurred.</entry>
+	  </row>
+	</tbody>
+      </tgroup>
+    </table>
+  </section>
 
 <!--
 Local Variables:
diff --git a/v4l2-spec/v4l2.sgml b/v4l2-spec/v4l2.sgml
index 470793d29..815e96ab5 100644
--- a/v4l2-spec/v4l2.sgml
+++ b/v4l2-spec/v4l2.sgml
@@ -131,6 +131,13 @@ structs, ioctls) must be noted in more detail in the history chapter
 applications. -->
 
       <revision>
+	<revnumber>0.26</revnumber>
+	<date>2009-06-15</date>
+	<authorinitials>hv</authorinitials>
+	<revremark>Finalized the RDS capture API.</revremark>
+      </revision>
+
+      <revision>
 	<revnumber>0.25</revnumber>
 	<date>2009-01-18</date>
 	<authorinitials>hv</authorinitials>
diff --git a/v4l2-spec/vidioc-g-tuner.sgml b/v4l2-spec/vidioc-g-tuner.sgml
index d5d379838..eb0b89e9a 100644
--- a/v4l2-spec/vidioc-g-tuner.sgml
+++ b/v4l2-spec/vidioc-g-tuner.sgml
@@ -120,9 +120,9 @@ field is not quite clear.--></para></entry>
 to decode audio subprograms. They will <emphasis>not</emphasis>
 change, for example with the current video standard.</para><para>When
 the structure refers to a radio tuner only the
-<constant>V4L2_TUNER_CAP_LOW</constant> and
-<constant>V4L2_TUNER_CAP_STEREO</constant> flags can be
-set.</para></entry>
+<constant>V4L2_TUNER_CAP_LOW</constant>,
+<constant>V4L2_TUNER_CAP_STEREO</constant> and
+<constant>V4L2_TUNER_CAP_RDS</constant> flags can be set.</para></entry>
 	  </row>
 	  <row>
 	    <entry>__u32</entry>
@@ -312,6 +312,12 @@ carrier for a monaural secondary language. Only
 supports the <constant>V4L2_STD_NTSC_M</constant> video
 standard.</para><!-- FIXME what if PAL+NTSC and Bi but not SAP? --></entry>
 	  </row>
+	  <row>
+	<entry><constant>V4L2_TUNER_CAP_RDS</constant></entry>
+	<entry>0x0080</entry>
+	<entry>RDS capture is supported. This capability is only valid for
+radio tuners.</entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>
@@ -353,6 +359,11 @@ bilingual audio signal (or a second audio program).</entry>
 <constant>V4L2_TUNER_SUB_SAP</constant> flag applies when the
 current video standard is <constant>V4L2_STD_NTSC_M</constant>.</entry>
 	  </row>
+	  <row>
+	    <entry><constant>V4L2_TUNER_SUB_RDS</constant></entry>
+	    <entry>0x0010</entry>
+	    <entry>The tuner receives an RDS channel.</entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>
diff --git a/v4l2-spec/vidioc-querycap.sgml b/v4l2-spec/vidioc-querycap.sgml
index 2715289d8..4a741f5e9 100644
--- a/v4l2-spec/vidioc-querycap.sgml
+++ b/v4l2-spec/vidioc-querycap.sgml
@@ -184,7 +184,7 @@ data.</entry>
 	  <row>
 	    <entry><constant>V4L2_CAP_RDS_CAPTURE</constant></entry>
 	    <entry>0x00000100</entry>
-	    <entry>[to be defined]</entry>
+	    <entry>The device supports the <link linkend="rds">RDS</link> interface.</entry>
 	  </row>
 	  <row>
 	    <entry><constant>V4L2_CAP_VIDEO_OUTPUT_OVERLAY</constant></entry>