| Message ID | 1525021993-17789-4-git-send-email-akinobu.mita@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Akinobu, On Mon, Apr 30, 2018 at 02:13:02AM +0900, Akinobu Mita wrote: > 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: Jacopo Mondi <jacopo+renesas@jmondi.org> > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Cc: Hans Verkuil <hans.verkuil@cisco.com> > Cc: Sakari Ailus <sakari.ailus@linux.intel.com> > Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> > Cc: Wolfram Sang <wsa@the-dreams.de> > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> As you have sent a separate series to move the SCCB case handling to the i2c core, and I feel like it may take some time to get there, as Sakari suggested, I'm fine with this change in the driver code. Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> Thanks j > --- > * v4 > - No changes > > drivers/media/i2c/ov772x.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) > > diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c > index e255070..b6223bf 100644 > --- a/drivers/media/i2c/ov772x.c > +++ b/drivers/media/i2c/ov772x.c > @@ -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) > -- > 2.7.4 >
diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c index e255070..b6223bf 100644 --- a/drivers/media/i2c/ov772x.c +++ b/drivers/media/i2c/ov772x.c @@ -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)
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: Jacopo Mondi <jacopo+renesas@jmondi.org> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Hans Verkuil <hans.verkuil@cisco.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> --- * v4 - No changes drivers/media/i2c/ov772x.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)