[media] V4L2: em28xx: register a V4L2 clock source

Camera sensors usually require a master clock for data sampling. This patch
registers such a clock source for em28xx cameras. This fixes the currently
broken em28xx ov2640 camera support and can also be used by other camera
sensors.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

3 files changed, 35 insertions, 10 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c
index 73cc50afa5e1..2f451e40edaf 100644
--- a/drivers/media/usb/em28xx/em28xx-camera.c
+++ b/drivers/media/usb/em28xx/em28xx-camera.c
@@ -22,6 +22,7 @@
 #include <linux/i2c.h>
 #include <media/soc_camera.h>
 #include <media/mt9v011.h>
+#include <media/v4l2-clk.h>
 #include <media/v4l2-common.h>
 
 #include "em28xx.h"
@@ -325,13 +326,24 @@ int em28xx_detect_sensor(struct em28xx *dev)
 
 int em28xx_init_camera(struct em28xx *dev)
 {
+        char clk_name[V4L2_SUBDEV_NAME_SIZE];
+        struct i2c_client *client = &dev->i2c_client[dev->def_i2c_bus];
+        struct i2c_adapter *adap = &dev->i2c_adap[dev->def_i2c_bus];
+        int ret = 0;
+
+        v4l2_clk_name_i2c(clk_name, sizeof(clk_name),
+                          i2c_adapter_id(adap), client->addr);
+        dev->clk = v4l2_clk_register_fixed(clk_name, "mclk", -EINVAL);
+        if (IS_ERR(dev->clk))
+                return PTR_ERR(dev->clk);
+
         switch (dev->em28xx_sensor) {
         case EM28XX_MT9V011:
         {
                 struct mt9v011_platform_data pdata;
                 struct i2c_board_info mt9v011_info = {
                         .type = "mt9v011",
-                        .addr = dev->i2c_client[dev->def_i2c_bus].addr,
+                        .addr = client->addr,
                         .platform_data = &pdata,
                 };
 
@@ -352,10 +364,11 @@ int em28xx_init_camera(struct em28xx *dev)
                 dev->sensor_xtal = 4300000;
                 pdata.xtal = dev->sensor_xtal;
                 if (NULL ==
-                    v4l2_i2c_new_subdev_board(&dev->v4l2_dev,
-                                              &dev->i2c_adap[dev->def_i2c_bus],
-                                              &mt9v011_info, NULL))
-                        return -ENODEV;
+                    v4l2_i2c_new_subdev_board(&dev->v4l2_dev, adap,
+                                              &mt9v011_info, NULL)) {
+                        ret = -ENODEV;
+                        break;
+                }
                 /* probably means GRGB 16 bit bayer */
                 dev->vinmode = 0x0d;
                 dev->vinctl = 0x00;
@@ -391,7 +404,7 @@ int em28xx_init_camera(struct em28xx *dev)
                 struct i2c_board_info ov2640_info = {
                         .type = "ov2640",
                         .flags = I2C_CLIENT_SCCB,
-                        .addr = dev->i2c_client[dev->def_i2c_bus].addr,
+                        .addr = client->addr,
                         .platform_data = &camlink,
                 };
                 struct v4l2_mbus_framefmt fmt;
@@ -408,9 +421,12 @@ int em28xx_init_camera(struct em28xx *dev)
                 dev->sensor_yres = 480;
 
                 subdev =
-                     v4l2_i2c_new_subdev_board(&dev->v4l2_dev,
-                                               &dev->i2c_adap[dev->def_i2c_bus],
+                     v4l2_i2c_new_subdev_board(&dev->v4l2_dev, adap,
                                                &ov2640_info, NULL);
+                if (NULL == subdev) {
+                        ret = -ENODEV;
+                        break;
+                }
 
                 fmt.code = V4L2_MBUS_FMT_YUYV8_2X8;
                 fmt.width = 640;
@@ -427,8 +443,13 @@ int em28xx_init_camera(struct em28xx *dev)
         }
         case EM28XX_NOSENSOR:
         default:
-                return -EINVAL;
+                ret = -EINVAL;
         }
 
-        return 0;
+        if (ret < 0) {
+                v4l2_clk_unregister_fixed(dev->clk);
+                dev->clk = NULL;
+        }
+
+        return ret;
 }
diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index 3765670f742a..464cec060fa4 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -36,6 +36,7 @@
 #include <media/tvaudio.h>
 #include <media/i2c-addr.h>
 #include <media/tveeprom.h>
+#include <media/v4l2-clk.h>
 #include <media/v4l2-common.h>
 
 #include "em28xx.h"
@@ -2857,6 +2858,8 @@ void em28xx_release_resources(struct em28xx *dev)
         if (dev->def_i2c_bus)
                 em28xx_i2c_unregister(dev, 1);
         em28xx_i2c_unregister(dev, 0);
+        if (dev->clk)
+                v4l2_clk_unregister_fixed(dev->clk);
 
         v4l2_ctrl_handler_free(&dev->ctrl_handler);
 
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index 205e9038b1c0..c9ebe19d064c 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -492,6 +492,7 @@ struct em28xx {
 
         struct v4l2_device v4l2_dev;
         struct v4l2_ctrl_handler ctrl_handler;
+        struct v4l2_clk *clk;
         struct em28xx_board board;
 
         /* Webcam specific fields */