From ab924af9acde26a5840b905c599dd4f3e10eaa00 Mon Sep 17 00:00:00 2001 From: Jacopo Mondi Date: Fri, 12 May 2017 09:36:59 -0300 Subject: [PATCH] [media] media: i2c: ov772x: Force use of SCCB protocol Commit e78902976150 ("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 Suggested-by: Laurent Pinchart Acked-by: Wolfram Sang Reviewed-by: Laurent Pinchart Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/soc_camera/ov772x.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/media/i2c/soc_camera/ov772x.c b/drivers/media/i2c/soc_camera/ov772x.c index 0f7b9d1b9c57..806383500313 100644 --- a/drivers/media/i2c/soc_camera/ov772x.c +++ b/drivers/media/i2c/soc_camera/ov772x.c @@ -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) -- 2.20.1