From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay5-d.mail.gandi.net ([217.70.183.197]:39863 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137AbeECPqv (ORCPT ); Thu, 3 May 2018 11:46:51 -0400 Date: Thu, 3 May 2018 17:46:43 +0200 From: jacopo mondi Subject: Re: [PATCH v4 03/14] media: ov772x: allow i2c controllers without I2C_FUNC_PROTOCOL_MANGLING Message-ID: <20180503154643.GC19612@w540> References: <1525021993-17789-1-git-send-email-akinobu.mita@gmail.com> <1525021993-17789-4-git-send-email-akinobu.mita@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ncSAzJYg3Aa9+CRW" Content-Disposition: inline In-Reply-To: <1525021993-17789-4-git-send-email-akinobu.mita@gmail.com> Sender: devicetree-owner@vger.kernel.org To: Akinobu Mita Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org, Jacopo Mondi , Laurent Pinchart , Hans Verkuil , Sakari Ailus , Mauro Carvalho Chehab , Wolfram Sang List-ID: --ncSAzJYg3Aa9+CRW Content-Type: text/plain; charset=utf-8 Content-Disposition: inline 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 > Cc: Laurent Pinchart > Cc: Hans Verkuil > Cc: Sakari Ailus > Cc: Mauro Carvalho Chehab > Cc: Wolfram Sang > Signed-off-by: Akinobu Mita 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 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 > --ncSAzJYg3Aa9+CRW Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJa6y7jAAoJEHI0Bo8WoVY8FKcQAIJweuIR2i8cbqot8QpADbdL Q1zLbhPCYqFxrKwiLa49sINDNdwpCJsqBFAL+Ef/Pt0RGDNbiZLA/MzL2RYdjVLR ELk/6P1gGOVMEAblIqGEnfWfwklUSg2mMU/wLmO+3CfPi5qNC+DktdaPjJgJx4TO Ez95JOPkZGFc3OXKh7xOGOTh8A0cR5DvkM4rKX1o1Ey4pbWOmeGB3EPbGmZp/Hy4 Cx4HLhuWlpsM7m5rMsH+VB3i5tQvxmTm7AwHlyuMUdAXHDtIiJHzeEkbrlUdK9OP xXIVMY9qkZB4gr8HGUhv1cBVSYRmiyJFNeMyIWzo6+4fkdbwHZX9GX4meVrKXrRq Uc7rAy/kmXu1zSHMv122R8SPRa5VbM0KCH+BfKZcR0PEG2zofBEEzaIYbnMeIM8p M2lXIAeHm7sVtUpT+mcLCXyzSCr+0ffGUWFgPX90APO5/80Mof5GEnLuv5caWLGj F0AJC+KGagyHn8y+UdT2mFSqO4mlLuKQK2NIoXDjcKk3B0zySUA8jEIPsXFAEHoK O4wGAfIywhW5tU71Z7cDavF+cmrfJ2ASITjd1VbUPOanZzZN/kzweQZk85C2Tojy QDNs1zEjlduUJNZEHjpvN/NH0aVnekrvVzbI61PiGK778dybm9aHYlwSQOM0edUZ IAKR/rSIljxd0XMrbiPj =ytqw -----END PGP SIGNATURE----- --ncSAzJYg3Aa9+CRW--