media: ov772x: allow i2c controllers without I2C_FUNC_PROTOCOL_MANGLING (0b964d18) · Commits · 戴 / test

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>

drivers/media/i2c/ov772x.c

+14 −6

Original line number	Diff line number	Diff line
		@@ -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)

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