V4L/DVB (12138): em28xx: add support for Silvercrest Webcam

This webcam uses a em2710 chipset, that identifies itself as em2820,
plus a mt9v011 sensor, and a DY-301P lens.

It needs a few different initializations than a normal em28xx device.

Thanks to Hans de Goede <hdegoede@redhat.com> and Douglas Landgraf
<dougsland@redhat.com> for providing the acces for the webcam during
this weekend, I could make a patch for it while returning back from
FISL/Fudcom LATAM 2009.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/video4linux/CARDLIST.em28xx

@@ -66,3 +66,4 @@
  68 -> Terratec AV350                           (em2860)        [0ccd:0084]
  69 -> KWorld ATSC 315U HDTV TV Box             (em2882)        [eb1a:a313]
  70 -> Evga inDtube                             (em2882)
+ 71 -> Silvercrest Webcam 1.3mpix               (em2820/em2840)

drivers/media/video/em28xx/Kconfig

@@ -8,6 +8,8 @@ config VIDEO_EM28XX
 	select VIDEO_SAA711X if VIDEO_HELPER_CHIPS_AUTO
 	select VIDEO_TVP5150 if VIDEO_HELPER_CHIPS_AUTO
 	select VIDEO_MSP3400 if VIDEO_HELPER_CHIPS_AUTO
+	select VIDEO_MT9V011 if VIDEO_HELPER_CHIPS_AUTO
+
 	---help---
 	  This is a video4linux driver for Empia 28xx based TV cards.
 

drivers/media/video/em28xx/em28xx-cards.c

@@ -191,6 +191,13 @@ static struct em28xx_reg_seq terratec_av350_unmute_gpio[] = {
 	{EM28XX_R08_GPIO,	0xff,	0xff,		10},
 	{	-1,		-1,	-1,		-1},
 };
+
+static struct em28xx_reg_seq silvercrest_reg_seq[] = {
+	{EM28XX_R08_GPIO,	0xff,	0xff,		10},
+	{EM28XX_R08_GPIO,	0x01,	0xf7,		10},
+	{	-1,		-1,	-1,		-1},
+};
+
 /*
  *  Board definitions
  */
@@ -438,6 +445,18 @@ struct em28xx_board em28xx_boards[] = {
 			.amux     = EM28XX_AMUX_VIDEO,
 		} },
 	},
+	[EM2820_BOARD_SILVERCREST_WEBCAM] = {
+		.name         = "Silvercrest Webcam 1.3mpix",
+		.tuner_type   = TUNER_ABSENT,
+		.is_27xx      = 1,
+		.decoder      = EM28XX_MT9V011,
+		.input        = { {
+			.type     = EM28XX_VMUX_COMPOSITE1,
+			.vmux     = 0,
+			.amux     = EM28XX_AMUX_VIDEO,
+			.gpio     = silvercrest_reg_seq,
+		} },
+	},
 	[EM2821_BOARD_SUPERCOMP_USB_2] = {
 		.name         = "Supercomp USB 2.0 TV",
 		.valid        = EM28XX_BOARD_NOT_VALIDATED,
@@ -1639,6 +1658,11 @@ static unsigned short tvp5150_addrs[] = {
 	I2C_CLIENT_END
 };
 
+static unsigned short mt9v011_addrs[] = {
+	0xba >> 1,
+	I2C_CLIENT_END
+};
+
 static unsigned short msp3400_addrs[] = {
 	0x80 >> 1,
 	0x88 >> 1,
@@ -1706,7 +1730,10 @@ void em28xx_pre_card_setup(struct em28xx *dev)
 			em28xx_info("chip ID is em2750\n");
 			break;
 		case CHIP_ID_EM2820:
-			em28xx_info("chip ID is em2820\n");
+			if (dev->board.is_27xx)
+				em28xx_info("chip is em2710\n");
+			else
+				em28xx_info("chip ID is em2820\n");
 			break;
 		case CHIP_ID_EM2840:
 			em28xx_info("chip ID is em2840\n");
@@ -2158,6 +2185,10 @@ void em28xx_card_setup(struct em28xx *dev)
 		   before probing the i2c bus. */
 		em28xx_set_mode(dev, EM28XX_ANALOG_MODE);
 		break;
+	case EM2820_BOARD_SILVERCREST_WEBCAM:
+		/* FIXME: need to document the registers bellow */
+		em28xx_write_reg(dev, 0x0d, 0x42);
+		em28xx_write_reg(dev, 0x13, 0x08);
 	}
 
 	if (dev->board.has_snapshot_button)
@@ -2189,6 +2220,10 @@ void em28xx_card_setup(struct em28xx *dev)
 		v4l2_i2c_new_probed_subdev(&dev->v4l2_dev, &dev->i2c_adap,
 			"tvp5150", "tvp5150", tvp5150_addrs);
 
+	if (dev->board.decoder == EM28XX_MT9V011)
+		v4l2_i2c_new_probed_subdev(&dev->v4l2_dev, &dev->i2c_adap,
+			"mt9v011", "mt9v011", mt9v011_addrs);
+
 	if (dev->board.adecoder == EM28XX_TVAUDIO)
 		v4l2_i2c_new_subdev(&dev->v4l2_dev, &dev->i2c_adap,
 			"tvaudio", "tvaudio", dev->board.tvaudio_addr);

drivers/media/video/em28xx/em28xx-core.c

@@ -648,17 +648,29 @@ int em28xx_capture_start(struct em28xx *dev, int start)
 int em28xx_set_outfmt(struct em28xx *dev)
 {
 	int ret;
+	int vinmode, vinctl, outfmt;
+
+	outfmt  = dev->format->reg;
+
+	if (dev->board.is_27xx) {
+		vinmode = 0x0d;
+		vinctl  = 0x00;
+		outfmt  = 0x24;
+	} else {
+		vinmode = 0x10;
+		vinctl  = 0x11;
+	}
 
 	ret = em28xx_write_reg_bits(dev, EM28XX_R27_OUTFMT,
-				    dev->format->reg | 0x20, 0x3f);
+				outfmt | 0x20, 0xff);
 	if (ret < 0)
-		return ret;
+			return ret;
 
-	ret = em28xx_write_reg(dev, EM28XX_R10_VINMODE, 0x10);
+	ret = em28xx_write_reg(dev, EM28XX_R10_VINMODE, vinmode);
 	if (ret < 0)
 		return ret;
 
-	return em28xx_write_reg(dev, EM28XX_R11_VINCTRL, 0x11);
+	return em28xx_write_reg(dev, EM28XX_R11_VINCTRL, vinctl);
 }
 
 static int em28xx_accumulator_set(struct em28xx *dev, u8 xmin, u8 xmax,
@@ -695,13 +707,19 @@ static int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)
 {
 	u8 mode;
 	/* the em2800 scaler only supports scaling down to 50% */
-	if (dev->board.is_em2800)
+
+	if (dev->board.is_27xx) {
+		/* FIXME: Don't use the scaler yet */
+		mode = 0;
+	} else if (dev->board.is_em2800) {
 		mode = (v ? 0x20 : 0x00) | (h ? 0x10 : 0x00);
-	else {
+	} else {
 		u8 buf[2];
+
 		buf[0] = h;
 		buf[1] = h >> 8;
 		em28xx_write_regs(dev, EM28XX_R30_HSCALELOW, (char *)buf, 2);
+
 		buf[0] = v;
 		buf[1] = v >> 8;
 		em28xx_write_regs(dev, EM28XX_R32_VSCALELOW, (char *)buf, 2);
@@ -720,8 +738,11 @@ int em28xx_resolution_set(struct em28xx *dev)
 	height = norm_maxh(dev) >> 1;
 
 	em28xx_set_outfmt(dev);
+
+
 	em28xx_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);
 	em28xx_capture_area_set(dev, 0, 0, width >> 2, height >> 2);
+
 	return em28xx_scaler_set(dev, dev->hscale, dev->vscale);
 }
 

drivers/media/video/em28xx/em28xx.h

@@ -107,6 +107,7 @@
 #define EM2860_BOARD_TERRATEC_AV350		  68
 #define EM2882_BOARD_KWORLD_ATSC_315U		  69
 #define EM2882_BOARD_EVGA_INDTUBE		  70
+#define EM2820_BOARD_SILVERCREST_WEBCAM           71
 
 /* Limits minimum and default number of buffers */
 #define EM28XX_MIN_BUF 4
@@ -360,6 +361,7 @@ enum em28xx_decoder {
 	EM28XX_NODECODER,
 	EM28XX_TVP5150,
 	EM28XX_SAA711X,
+	EM28XX_MT9V011,
 };
 
 enum em28xx_adecoder {
@@ -388,6 +390,7 @@ struct em28xx_board {
 	unsigned int max_range_640_480:1;
 	unsigned int has_dvb:1;
 	unsigned int has_snapshot_button:1;
+	unsigned int is_27xx:1;
 	unsigned int valid:1;
 
 	unsigned char xclk, i2c_speed;