From 2bf7de48888fceed8d8e5cddd51f1d474bdbfae6 Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Sun, 28 Feb 2010 21:02:55 -0300
Subject: 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>
---
drivers/media/video/ov7670.c | 34 ++++++++++++++++++++++++++++++----
1 file changed, 30 insertions(+), 4 deletions(-)
(limited to 'drivers/media/video/ov7670.c')
diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
index b2e6f8e730a..95507770f12 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;
--
cgit v1.2.3-18-g5258