[media] em28xx: add support for EM28174 chip

EM28174 is very similar as already supported EM2874.
I am not sure what are differences, but it could be analog support.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

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

@@ -2810,6 +2810,11 @@ static int em28xx_init_dev(struct em28xx **devhandle, struct usb_device *udev,
 			dev->reg_gpio_num = EM2874_R80_GPIO;
 			dev->wait_after_write = 0;
 			break;
+		case CHIP_ID_EM28174:
+			em28xx_info("chip ID is em28174\n");
+			dev->reg_gpio_num = EM2874_R80_GPIO;
+			dev->wait_after_write = 0;
+			break;
 		case CHIP_ID_EM2883:
 			em28xx_info("chip ID is em2882/em2883\n");
 			dev->wait_after_write = 0;

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

@@ -614,7 +614,7 @@ int em28xx_capture_start(struct em28xx *dev, int start)
 {
 	int rc;
 
-	if (dev->chip_id == CHIP_ID_EM2874) {
+	if (dev->chip_id == CHIP_ID_EM2874 || dev->chip_id == CHIP_ID_EM28174) {
 		/* The Transport Stream Enable Register moved in em2874 */
 		if (!start) {
 			rc = em28xx_write_reg_bits(dev, EM2874_R5F_TS_ENABLE,
@@ -1111,6 +1111,10 @@ int em28xx_isoc_dvb_max_packetsize(struct em28xx *dev)
 		/* FIXME - for now assume 564 like it was before, but the
 		   em2874 code should be added to return the proper value... */
 		packet_size = 564;
+	} else if (dev->chip_id == CHIP_ID_EM28174) {
+		/* FIXME same as em2874. 564 was enough for 22 Mbit DVB-T
+		   but too much for 44 Mbit DVB-C. */
+		packet_size = 752;
 	} else {
 		/* TS max packet size stored in bits 1-0 of R01 */
 		chip_cfg2 = em28xx_read_reg(dev, EM28XX_R01_CHIPCFG2);

drivers/media/video/em28xx/em28xx-i2c.c

@@ -332,7 +332,7 @@ static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
 	struct em28xx_eeprom *em_eeprom = (void *)eedata;
 	int i, err, size = len, block;
 
-	if (dev->chip_id == CHIP_ID_EM2874) {
+	if (dev->chip_id == CHIP_ID_EM2874 || dev->chip_id == CHIP_ID_EM28174) {
 		/* Empia switched to a 16-bit addressable eeprom in newer
 		   devices.  While we could certainly write a routine to read
 		   the eeprom, there is nothing of use in there that cannot be

drivers/media/video/em28xx/em28xx-reg.h

@@ -201,6 +201,7 @@ enum em28xx_chip_id {
 	CHIP_ID_EM2870 = 35,
 	CHIP_ID_EM2883 = 36,
 	CHIP_ID_EM2874 = 65,
+	CHIP_ID_EM28174 = 113,
 };
 
 /*