History log of /linux-master/drivers/media/i2c/ml86v7667.c
Revision Date Author Comments
# aaeb31c0 14-May-2023 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

media: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
commit 03c835f498b5 ("i2c: Switch .probe() to not take an id parameter")
convert back to (the new) .probe() to be able to eventually drop
.probe_new() from struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>


# c14e8589 18-Nov-2022 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

media: i2c/ml86v7667: Convert to i2c's .probe_new()

The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>


# ed5c2f5f 15-Aug-2022 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

i2c: Make remove callback return void

The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>


# 6a7bdd89 03-Jan-2022 Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

media: v4l2-mediabus: Use structures to describe bus configuration

The media bus configuration is specified through a set of flags, some of
which being mutually exclusive. This doesn't scale to express more
complex configurations. Improve the API by replacing the single flags
field in v4l2_mbus_config by a union of v4l2_mbus_config_* structures.
The flags themselves are still used in those structures, so they are
kept here. Drivers are however updated to use structure fields instead
of flags when already possible.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>


# 0d346d2a 10-Jun-2021 Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

media: v4l2-subdev: add subdev-wide state struct

We have 'struct v4l2_subdev_pad_config' which contains configuration for
a single pad used for the TRY functionality, and an array of those
structs is passed to various v4l2_subdev_pad_ops.

I was working on subdev internal routing between pads, and realized that
there's no way to add TRY functionality for routes, which is not pad
specific configuration. Adding a separate struct for try-route config
wouldn't work either, as e.g. set-fmt needs to know the try-route
configuration to propagate the settings.

This patch adds a new struct, 'struct v4l2_subdev_state' (which at the
moment only contains the v4l2_subdev_pad_config array) and the new
struct is used in most of the places where v4l2_subdev_pad_config was
used. All v4l2_subdev_pad_ops functions taking v4l2_subdev_pad_config
are changed to instead take v4l2_subdev_state.

The changes to drivers/media/v4l2-core/v4l2-subdev.c and
include/media/v4l2-subdev.h were written by hand, and all the driver
changes were done with the semantic patch below. The spatch needs to be
applied to a select list of directories. I used the following shell
commands to apply the spatch:

dirs="drivers/media/i2c drivers/media/platform drivers/media/usb drivers/media/test-drivers/vimc drivers/media/pci drivers/staging/media"
for dir in $dirs; do spatch -j8 --dir --include-headers --no-show-diff --in-place --sp-file v4l2-subdev-state.cocci $dir; done

Note that Coccinelle chokes on a few drivers (gcc extensions?). With
minor changes we can make Coccinelle run fine, and these changes can be
reverted after spatch. The diff for these changes is:

For drivers/media/i2c/s5k5baf.c:

@@ -1481,7 +1481,7 @@ static int s5k5baf_set_selection(struct v4l2_subdev *sd,
&s5k5baf_cis_rect,
v4l2_subdev_get_try_crop(sd, cfg, PAD_CIS),
v4l2_subdev_get_try_compose(sd, cfg, PAD_CIS),
- v4l2_subdev_get_try_crop(sd, cfg, PAD_OUT)
+ v4l2_subdev_get_try_crop(sd, cfg, PAD_OUT),
};
s5k5baf_set_rect_and_adjust(rects, rtype, &sel->r);
return 0;

For drivers/media/platform/s3c-camif/camif-capture.c:

@@ -1230,7 +1230,7 @@ static int s3c_camif_subdev_get_fmt(struct v4l2_subdev *sd,
*mf = camif->mbus_fmt;
break;

- case CAMIF_SD_PAD_SOURCE_C...CAMIF_SD_PAD_SOURCE_P:
+ case CAMIF_SD_PAD_SOURCE_C:
/* crop rectangle at camera interface input */
mf->width = camif->camif_crop.width;
mf->height = camif->camif_crop.height;
@@ -1332,7 +1332,7 @@ static int s3c_camif_subdev_set_fmt(struct v4l2_subdev *sd,
}
break;

- case CAMIF_SD_PAD_SOURCE_C...CAMIF_SD_PAD_SOURCE_P:
+ case CAMIF_SD_PAD_SOURCE_C:
/* Pixel format can be only changed on the sink pad. */
mf->code = camif->mbus_fmt.code;
mf->width = crop->width;

The semantic patch is:

// <smpl>

// Change function parameter

@@
identifier func;
identifier cfg;
@@

func(...,
- struct v4l2_subdev_pad_config *cfg
+ struct v4l2_subdev_state *sd_state
, ...)
{
<...
- cfg
+ sd_state
...>
}

// Change function declaration parameter

@@
identifier func;
identifier cfg;
type T;
@@
T func(...,
- struct v4l2_subdev_pad_config *cfg
+ struct v4l2_subdev_state *sd_state
, ...);

// Change function return value

@@
identifier func;
@@
- struct v4l2_subdev_pad_config
+ struct v4l2_subdev_state
*func(...)
{
...
}

// Change function declaration return value

@@
identifier func;
@@
- struct v4l2_subdev_pad_config
+ struct v4l2_subdev_state
*func(...);

// Some drivers pass a local pad_cfg for a single pad to a called function. Wrap it
// inside a pad_state.

@@
identifier func;
identifier pad_cfg;
@@
func(...)
{
...
struct v4l2_subdev_pad_config pad_cfg;
+ struct v4l2_subdev_state pad_state = { .pads = &pad_cfg };

<+...

(
v4l2_subdev_call
|
sensor_call
|
isi_try_fse
|
isc_try_fse
|
saa_call_all
)
(...,
- &pad_cfg
+ &pad_state
,...)

...+>
}

// If the function uses fields from pad_config, access via state->pads

@@
identifier func;
identifier state;
@@
func(...,
struct v4l2_subdev_state *state
, ...)
{
<...
(
- state->try_fmt
+ state->pads->try_fmt
|
- state->try_crop
+ state->pads->try_crop
|
- state->try_compose
+ state->pads->try_compose
)
...>
}

// If the function accesses the filehandle, use fh->state instead

@@
struct v4l2_subdev_fh *fh;
@@
- fh->pad
+ fh->state

@@
struct v4l2_subdev_fh fh;
@@
- fh.pad
+ fh.state

// Start of vsp1 specific

@@
@@
struct vsp1_entity {
...
- struct v4l2_subdev_pad_config *config;
+ struct v4l2_subdev_state *config;
...
};

@@
symbol entity;
@@
vsp1_entity_init(...)
{
...
entity->config =
- v4l2_subdev_alloc_pad_config
+ v4l2_subdev_alloc_state
(&entity->subdev);
...
}

@@
symbol entity;
@@
vsp1_entity_destroy(...)
{
...
- v4l2_subdev_free_pad_config
+ v4l2_subdev_free_state
(entity->config);
...
}

@exists@
identifier func =~ "(^vsp1.*)|(hsit_set_format)|(sru_enum_frame_size)|(sru_set_format)|(uif_get_selection)|(uif_set_selection)|(uds_enum_frame_size)|(uds_set_format)|(brx_set_format)|(brx_get_selection)|(histo_get_selection)|(histo_set_selection)|(brx_set_selection)";
symbol config;
@@
func(...) {
...
- struct v4l2_subdev_pad_config *config;
+ struct v4l2_subdev_state *config;
...
}

// End of vsp1 specific

// Start of rcar specific

@@
identifier sd;
identifier pad_cfg;
@@
rvin_try_format(...)
{
...
- struct v4l2_subdev_pad_config *pad_cfg;
+ struct v4l2_subdev_state *sd_state;
...
- pad_cfg = v4l2_subdev_alloc_pad_config(sd);
+ sd_state = v4l2_subdev_alloc_state(sd);
<...
- pad_cfg
+ sd_state
...>
- v4l2_subdev_free_pad_config(pad_cfg);
+ v4l2_subdev_free_state(sd_state);
...
}

// End of rcar specific

// Start of rockchip specific

@@
identifier func =~ "(rkisp1_rsz_get_pad_fmt)|(rkisp1_rsz_get_pad_crop)|(rkisp1_rsz_register)";
symbol rsz;
symbol pad_cfg;
@@

func(...)
{
+ struct v4l2_subdev_state state = { .pads = rsz->pad_cfg };
...
- rsz->pad_cfg
+ &state
...
}

@@
identifier func =~ "(rkisp1_isp_get_pad_fmt)|(rkisp1_isp_get_pad_crop)";
symbol isp;
symbol pad_cfg;
@@

func(...)
{
+ struct v4l2_subdev_state state = { .pads = isp->pad_cfg };
...
- isp->pad_cfg
+ &state
...
}

@@
symbol rkisp1;
symbol isp;
symbol pad_cfg;
@@

rkisp1_isp_register(...)
{
+ struct v4l2_subdev_state state = { .pads = rkisp1->isp.pad_cfg };
...
- rkisp1->isp.pad_cfg
+ &state
...
}

// End of rockchip specific

// Start of tegra-video specific

@@
identifier sd;
identifier pad_cfg;
@@
__tegra_channel_try_format(...)
{
...
- struct v4l2_subdev_pad_config *pad_cfg;
+ struct v4l2_subdev_state *sd_state;
...
- pad_cfg = v4l2_subdev_alloc_pad_config(sd);
+ sd_state = v4l2_subdev_alloc_state(sd);
<...
- pad_cfg
+ sd_state
...>
- v4l2_subdev_free_pad_config(pad_cfg);
+ v4l2_subdev_free_state(sd_state);
...
}

@@
identifier sd_state;
@@
__tegra_channel_try_format(...)
{
...
struct v4l2_subdev_state *sd_state;
<...
- sd_state->try_crop
+ sd_state->pads->try_crop
...>
}

// End of tegra-video specific

// </smpl>

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>


# 0c3da525 17-Jul-2020 Jacopo Mondi <jacopo+renesas@jmondi.org>

media: i2c: Use the new get_mbus_config pad op

Move the existing users of the g_mbus_config video operation to use the
newly introduced get_mbus_config pad operations.

All the ported drivers report a static media bus configuration and do no
support s_mbus_config so the operation implementation has not changed.

Bridge drivers needs to call the new pad operation and will receive an
-ENOICTLCMD when calling the old g_mbus_config video operation

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>


# 2874c5fd 27-May-2019 Thomas Gleixner <tglx@linutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 5610ced4 13-Dec-2016 Bhumika Goyal <bhumirks@gmail.com>

[media] drivers: media: i2c: ml86v7667: constify v4l2_subdev_* structures

v4l2_subdev_{core/video}_ops structures are stored in the
fields of the v4l2_subdev_ops structure which are of type const.
Also, v4l2_subdev_ops structure is passed to a function
having its argument of type const. As these structures are never
modified, so declare them as const.
Done using Coccinelle: (One of the scripts used)

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct v4l2_subdev_ops i@p = {...};

@ok1@
identifier r1.i;
position p;
@@
v4l2_i2c_subdev_init(...,&i@p)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct v4l2_subdev_ops i;

File size before:
text data bss dec hex filename
2732 608 8 3348 d14 drivers/media/i2c/ml86v7667.o

File size after:
text data bss dec hex filename
3100 232 8 3340 d0c drivers/media/i2c/ml86v7667.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>


# edf8875f 01-Oct-2015 Fengguang Wu <fengguang.wu@intel.com>

[media] i2c: fix platform_no_drv_owner.cocci warnings

drivers/media/i2c/ml86v7667.c:430:3-8: No need to set .owner here. The core will do it.

Remove .owner field if calls are used which set it automatically

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

CC: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


# 280e87b2 03-Sep-2015 Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

[media] ml86v7667: implement g_std() method

The driver was written with the 'soc_camera' use in mind, however the g_std()
video method was forgotten. Implement it at last...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


# da298c6d 09-Apr-2015 Hans Verkuil <hans.verkuil@cisco.com>

[media] v4l2: replace video op g_mbus_fmt by pad op get_fmt

The g_mbus_fmt video op is a duplicate of the pad op. Replace all uses
by the get_fmt pad op and remove the video op.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Cc: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


# ebcff5fc 09-Apr-2015 Hans Verkuil <hans.verkuil@cisco.com>

[media] v4l2: replace enum_mbus_fmt by enum_mbus_code

Replace all calls to the enum_mbus_fmt video op by the pad
enum_mbus_code op and remove the duplicate video op.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Scott Jiang <scott.jiang.linux@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kamil Debski <k.debski@samsung.com>
Acked-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


# f5fe58fd 10-Nov-2014 Boris Brezillon <bbrezillon@kernel.org>

[media] i2c: Make use of media_bus_format enum

In order to have subsytem agnostic media bus format definitions we've
moved media bus definitions to include/uapi/linux/media-bus-format.h and
prefixed values with MEDIA_BUS_FMT instead of V4L2_MBUS_FMT.

Replace all references to the old definitions in i2c drivers.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


# 8774bed9 28-Apr-2014 Laurent Pinchart <laurent.pinchart@ideasonboard.com>

[media] v4l: subdev: Move [gs]_std operation to video ops

The g_std and s_std operations are video-related, move them to the video
ops where they belong.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>


# 037f4e6b 30-Jun-2013 Hans Verkuil <hans.verkuil@cisco.com>

[media] ml86v7667: fix compile warning: 'ret' set but not used

media_build/v4l/ml86v7667.c: In function 'ml86v7667_s_ctrl':
media_build/v4l/ml86v7667.c:120:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
int ret;
^
And indeed, ret is set but not used. Let's actually return the error
code.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>


# 2fa8de19 15-Jul-2013 Vladimir Barinov <vladimir.barinov@cogentembedded.com>

[media] ml86v7667: override default field interlace order

ML86V7667 always transmits top field first for both PAL and NTSC -- that makes
application incorrectly treat interlaced fields when relying on the standard.
Hence we must set V4L2_FIELD_INTERLACED_TB format explicitly.

[Sergei: added a comment.]

Reported-by: Katsuya MATSUBARA <matsu@igel.co.jp>
Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Tested-by: Katsuya MATSUBARA <matsu@igel.co.jp>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>


# 3f1a94ba 30-Jun-2013 Hans Verkuil <hans.verkuil@cisco.com>

[media] ml86v7667: fix compile warning: 'ret' set but not used

media_build/v4l/ml86v7667.c: In function 'ml86v7667_s_ctrl':
media_build/v4l/ml86v7667.c:120:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
int ret;
^
And indeed, ret is set but not used. Let's actually return the error
code.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>


# 2641ff99 20-Jun-2013 Hans Verkuil <hans.verkuil@cisco.com>

[media] ml86v7667: fix compiler warning

build/media_build/v4l/ml86v7667.c: In function 'ml86v7667_s_ctrl':
build/media_build/v4l/ml86v7667.c:120:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
int ret = 0;
^

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Vladimir Barinov <source@cogentembedded.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>


# d13ac96f 31-May-2013 Hans Verkuil <hans.verkuil@cisco.com>

[media] ml86v7667: fix the querystd implementation

The *std should be set to V4L2_STD_UNKNOWN, not the function's return code.
Also, *std should be ANDed with 525_60 or 625_50.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>


# ed3e12d2 29-May-2013 Vladimir Barinov <vladimir.barinov@cogentembedded.com>

[media] ML86V7667: new video decoder driver

Add OKI Semiconductor ML86V7667 video decoder driver.
[Sergei: added v4l2_device_unregister_subdev() call to the error cleanup path
of ml86v7667_probe(), renamed ml86v7667_try_mbus_fmt() to ml86v7667_mbus_fmt(),
killed v4l2_chip_match_i2c_client() checks in the [gs]_register() methods, fixed
the prototype of the s_register() method, did some cleanup.]

Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>