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media: ov772x: allow i2c controllers without I2C_FUNC_PROTOCOL_MANGLING

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The ov772x driver only works when the i2c controller have
I2C_FUNC_PROTOCOL_MANGLING.  However, many i2c controller drivers don't
support it.

The reason that the ov772x requires I2C_FUNC_PROTOCOL_MANGLING is that
it doesn't support repeated starts.

This changes the reading ov772x register method so that it doesn't
require I2C_FUNC_PROTOCOL_MANGLING by calling two separated i2c messages.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Akinobu Mita 2018-05-06 10:19:18 -04:00 committed by Mauro Carvalho Chehab
parent c3f3ba3e6f
commit 0b964d183c
1 changed files with 14 additions and 6 deletions
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20
drivers/media/i2c/ov772x.c
View file

@ -542,9 +542,19 @@ static struct ov772x_priv *to_ov772x(struct v4l2_subdev *sd)
return container_of(sd, struct ov772x_priv, subdev);
}
static inline int ov772x_read(struct i2c_client *client, u8 addr)
static int ov772x_read(struct i2c_client *client, u8 addr)
{
return i2c_smbus_read_byte_data(client, addr);
int ret;
u8 val;
ret = i2c_master_send(client, &addr, 1);
if (ret < 0)
return ret;
ret = i2c_master_recv(client, &val, 1);
if (ret < 0)
return ret;
return val;
}
static inline int ov772x_write(struct i2c_client *client, u8 addr, u8 value)
@ -1255,13 +1265,11 @@ static int ov772x_probe(struct i2c_client *client,
return -EINVAL;
}
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_PROTOCOL_MANGLING)) {
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
dev_err(&adapter->dev,
"I2C-Adapter doesn't support SMBUS_BYTE_DATA or PROTOCOL_MANGLING\n");
"I2C-Adapter doesn't support SMBUS_BYTE_DATA\n");
return -EIO;
}
client->flags |= I2C_CLIENT_SCCB;
priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)