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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Akinobu Mita <akinobu.mita@gmail.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL 4.18 076/136] media: ov772x: allow i2c controllers
 without I2C_FUNC_PROTOCOL_MANGLING
Thread-Topic: [PATCH AUTOSEL 4.18 076/136] media: ov772x: allow i2c
 controllers without I2C_FUNC_PROTOCOL_MANGLING
Thread-Index: AQHUTjKpBY6WC5jwwkKUl21NBZlQYA==
Date:   Mon, 17 Sep 2018 03:00:59 +0000
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From: Akinobu Mita <akinobu.mita@gmail.com>

[ 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 <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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 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 ef6581e56753..3fdbe644648a 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_subde=
v *sd)
 	return container_of(sd, struct ov772x_priv, subdev);
 }
=20
-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 =3D i2c_master_send(client, &addr, 1);
+	if (ret < 0)
+		return ret;
+	ret =3D i2c_master_recv(client, &val, 1);
+	if (ret < 0)
+		return ret;
+
+	return val;
 }
=20
 static inline int ov772x_write(struct i2c_client *client, u8 addr, u8 valu=
e)
@@ -1263,13 +1273,11 @@ static int ov772x_probe(struct i2c_client *client,
 		return -EINVAL;
 	}
=20
-	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 |=3D I2C_CLIENT_SCCB;
=20
 	priv =3D devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
--=20
2.17.1