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[media] media: i2c: ov772x: Force use of SCCB protocol 

Commit e789029761 ("i2c: sh_mobile: don't send a stop condition by
default inside transfers") makes the i2c_sh_mobile I2C-adapter emit a
stop/start sequence between messages in a single transfer only when
explicitly requested with I2C_M_STOP.

This breaks the ov772x driver in the SH4 Migo-R board as the Omnivision
sensor uses the I2C-like SCCB protocol that doesn't support repeated
starts:

i2c-sh_mobile i2c-sh_mobile.0: Transfer request timed out
ov772x 0-0021: Product ID error 92:92

Fix it by marking the client as SCCB, forcing the emission of a
stop/start sequence between all messages.
As I2C_M_STOP requires the I2C adapter to support protocol mangling,
ensure that the I2C_FUNC_PROTOCOL_MANGLING functionality is available.

Tested on SH4 Migo-R board, with OV772x now successfully probing

soc-camera-pdrv soc-camera-pdrv.0: Probing soc-camera-pdrv.0
ov772x 0-0021: ov7725 Product ID 77:21 Manufacturer ID 7f:a2

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Jacopo Mondi 2017-05-12 09:36:59 -03:00 committed by Mauro Carvalho Chehab
parent affd250dec
commit ab924af9ac
1 changed files with 4 additions and 2 deletions
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6
drivers/media/i2c/soc_camera/ov772x.c
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@ -1047,11 +1047,13 @@ static int ov772x_probe(struct i2c_client *client,
return -EINVAL;
}
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_PROTOCOL_MANGLING)) {
dev_err(&adapter->dev,
"I2C-Adapter doesn't support I2C_FUNC_SMBUS_BYTE_DATA\n");
"I2C-Adapter doesn't support SMBUS_BYTE_DATA or PROTOCOL_MANGLING\n");
return -EIO;
}
client->flags |= I2C_CLIENT_SCCB;
priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)