V4L/DVB: ov7670: Don't use SMBUS I/O

Contrary to my earlier belief, the ov7670 is not actually an SMBUS device,
though it will pretend to be one if it's in a good mood.  Unfortunately,
it's rarely in a good mood, especially on the XO 1.5.  So use low-level i2c
I/O instead.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 30 insertions, 4 deletions

diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
index b2e6f8e730a3..95507770f120 100644
--- a/drivers/media/video/ov7670.c
+++ b/drivers/media/video/ov7670.c
@@ -410,16 +410,33 @@ static struct regval_list ov7670_fmt_raw[] = {
 /*
  * Low-level register I/O.
  */
-
 static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,
                 unsigned char *value)
 {
         struct i2c_client *client = v4l2_get_subdevdata(sd);
+        u8 data = reg;
+        struct i2c_msg msg;
         int ret;
 
-        ret = i2c_smbus_read_byte_data(client, reg);
+        /*
+         * Send out the register address...
+         */
+        msg.addr = client->addr;
+        msg.flags = 0;
+        msg.len = 1;
+        msg.buf = &data;
+        ret = i2c_transfer(client->adapter, &msg, 1);
+        if (ret < 0) {
+                printk(KERN_ERR "Error %d on register write\n", ret);
+                return ret;
+        }
+        /*
+         * ...then read back the result.
+         */
+        msg.flags = I2C_M_RD;
+        ret = i2c_transfer(client->adapter, &msg, 1);
         if (ret >= 0) {
-                *value = (unsigned char)ret;
+                *value = data;
                 ret = 0;
         }
         return ret;
@@ -430,8 +447,17 @@ static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,
                 unsigned char value)
 {
         struct i2c_client *client = v4l2_get_subdevdata(sd);
-        int ret = i2c_smbus_write_byte_data(client, reg, value);
+        struct i2c_msg msg;
+        unsigned char data[2] = { reg, value };
+        int ret;
 
+        msg.addr = client->addr;
+        msg.flags = 0;
+        msg.len = 2;
+        msg.buf = data;
+        ret = i2c_transfer(client->adapter, &msg, 1);
+        if (ret > 0)
+                ret = 0;
         if (reg == REG_COM7 && (value & COM7_RESET))
                 msleep(5);  /* Wait for reset to run */
         return ret;