4.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: Akinobu Mita <[email protected]> [ Upstream commit 0b964d183cbf3f95a062ad9f3eec87ffa2790558 ] 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 <[email protected]> Cc: Hans Verkuil <[email protected]> Cc: Wolfram Sang <[email protected]> Reviewed-by: Jacopo Mondi <[email protected]> Signed-off-by: Akinobu Mita <[email protected]> Signed-off-by: Sakari Ailus <[email protected]> Signed-off-by: Mauro Carvalho Chehab <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/media/i2c/ov772x.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) --- a/drivers/media/i2c/ov772x.c +++ b/drivers/media/i2c/ov772x.c @@ -542,9 +542,19 @@ static struct ov772x_priv *to_ov772x(str 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) @@ -1263,13 +1273,11 @@ static int ov772x_probe(struct i2c_clien 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)
