[media] em28xx: add support for registering multiple i2c buses

Register both buses 0 and 1 via I2C API. For now, bus 0 is used
only by eeprom on all known devices. Later patches will be needed
if this changes in the future.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index 16ab4d7..6e62b72 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -2235,8 +2235,8 @@
 		dev->board.i2c_speed = EM28XX_I2C_CLK_WAIT_ENABLE |
 				       EM28XX_I2C_FREQ_100_KHZ;
 
-	if (dev->board.def_i2c_bus == 1)
-		dev->board.i2c_speed |= EM2874_I2C_SECONDARY_BUS_SELECT;
+	/* Should be initialized early, for I2C to work */
+	dev->def_i2c_bus = dev->board.def_i2c_bus;
 }
 
 
@@ -2642,7 +2642,7 @@
 
 	/* user did not request i2c scanning => do it now */
 	if (!dev->i2c_hash)
-		em28xx_do_i2c_scan(dev);
+		em28xx_do_i2c_scan(dev, dev->def_i2c_bus);
 
 	for (i = 0; i < ARRAY_SIZE(em28xx_i2c_hash); i++) {
 		if (dev->i2c_hash == em28xx_i2c_hash[i].hash) {
@@ -2953,7 +2953,9 @@
 
 	em28xx_release_analog_resources(dev);
 
-	em28xx_i2c_unregister(dev);
+	if (dev->def_i2c_bus)
+		em28xx_i2c_unregister(dev, 1);
+	em28xx_i2c_unregister(dev, 0);
 
 	v4l2_ctrl_handler_free(&dev->ctrl_handler);
 
@@ -3109,14 +3111,25 @@
 	v4l2_ctrl_handler_init(hdl, 8);
 	dev->v4l2_dev.ctrl_handler = hdl;
 
-	/* register i2c bus */
-	retval = em28xx_i2c_register(dev);
+	rt_mutex_init(&dev->i2c_bus_lock);
+
+	/* register i2c bus 0 */
+	retval = em28xx_i2c_register(dev, 0);
 	if (retval < 0) {
-		em28xx_errdev("%s: em28xx_i2c_register - error [%d]!\n",
+		em28xx_errdev("%s: em28xx_i2c_register bus 0 - error [%d]!\n",
 			__func__, retval);
 		goto unregister_dev;
 	}
 
+	if (dev->def_i2c_bus) {
+		retval = em28xx_i2c_register(dev, 1);
+		if (retval < 0) {
+			em28xx_errdev("%s: em28xx_i2c_register bus 1 - error [%d]!\n",
+				__func__, retval);
+			goto unregister_dev;
+		}
+	}
+
 	/*
 	 * Default format, used for tvp5150 or saa711x output formats
 	 */
@@ -3186,7 +3199,9 @@
 	return 0;
 
 fail:
-	em28xx_i2c_unregister(dev);
+	if (dev->def_i2c_bus)
+		em28xx_i2c_unregister(dev, 1);
+	em28xx_i2c_unregister(dev, 0);
 	v4l2_ctrl_handler_free(&dev->ctrl_handler);
 
 unregister_dev: