From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84A91C3A5A2 for ; Fri, 23 Aug 2019 10:01:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3950D23426 for ; Fri, 23 Aug 2019 10:01:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="JZjOpKJH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391550AbfHWKBe (ORCPT ); Fri, 23 Aug 2019 06:01:34 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:34560 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391107AbfHWKBd (ORCPT ); Fri, 23 Aug 2019 06:01:33 -0400 Received: by mail-pf1-f196.google.com with SMTP id b24so6157661pfp.1 for ; Fri, 23 Aug 2019 03:01:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ZxM74Kyn3vZ+th1DbRlhNF+/q8zOmm1ovF5THAevQQM=; b=JZjOpKJHoUYRrLpakHjc97b9CEk91GJT7FTFH7UAfSkmUgCZdNBBf+q9wSsq414IKA xlF7jWhjdeKACV0jLzhfLCL4SZpusMOA6fI19IB/531cv7EjVD9s14wyZbcxozydK7c6 Evf3z55f76ZuAAKmPszOobDhsENxL3LXFCYwg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ZxM74Kyn3vZ+th1DbRlhNF+/q8zOmm1ovF5THAevQQM=; b=P4I1wpiuH1GsX4CO3Bs0sjyIEj/ZJs3luWrLg6KU9rZ7+1EypkK/03YlHvYvFtZw4v ROJiE3nUZ/dgP+23ljgrUcRC1ppbuUKi0HYRM2mxG7xNa4mRneuiCwzRYqn5/QnGym36 LYzdaThzQZRhkBPCduzKR0+CGubJrsUBfSzLh7EpyBtc6H+FUdl7F2eypI7XNRNJe4xQ obsaf33zwIE00q2KolgBnnlK63kDwQ09pOfDqeBiC7QAohPmedvVCy0U23OLoTE1HEta mwgjWUUjE+OIQJrKArJ9OrnrOIxZXGwOZOiMq3CkQ7orPrOrsGjX9YNqih091SzE6Ulb 4QCA== X-Gm-Message-State: APjAAAUa3gQy/jJF/LxpRuSZ2/UgRGQqIIwnW4iEVhOgRyZ7VswOUriG y6zX1rkB7cbIW1hfysd86qFUgw== X-Google-Smtp-Source: APXvYqyZPDyWUxmmKNelYf7xhlS+OtgyrzK2fy9Ri+dz5xWSKAIL+vJUlelv/74klwpO/vydDLpObA== X-Received: by 2002:a62:87c8:: with SMTP id i191mr4248619pfe.133.1566554492579; Fri, 23 Aug 2019 03:01:32 -0700 (PDT) Received: from chromium.org ([2401:fa00:4:4:6d27:f13:a0fa:d4b6]) by smtp.gmail.com with ESMTPSA id i137sm1942360pgc.4.2019.08.23.03.01.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Aug 2019 03:01:31 -0700 (PDT) Date: Fri, 23 Aug 2019 19:01:26 +0900 From: Tomasz Figa To: dongchun.zhu@mediatek.com Cc: mchehab@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, sakari.ailus@linux.intel.com, drinkcat@chromium.org, matthias.bgg@gmail.com, bingbu.cao@intel.com, srv_heupstream@mediatek.com, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, sj.huang@mediatek.com, linux-media@vger.kernel.org, devicetree@vger.kernel.org, louis.kuo@mediatek.com, shengnan.wang@mediatek.com Subject: Re: [V1, 2/2] media: i2c: Add more sensor mode for ov8856 camera sensor Message-ID: <20190823100126.GB33937@chromium.org> References: <20190808092215.5608-1-dongchun.zhu@mediatek.com> <20190808092215.5608-3-dongchun.zhu@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190808092215.5608-3-dongchun.zhu@mediatek.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Dongchun, On Thu, Aug 08, 2019 at 05:22:15PM +0800, dongchun.zhu@mediatek.com wrote: > From: Dongchun Zhu > > This patch mainly adds two more sensor modes for OV8856 image sensor. > The OV8856 driver currently supports output format: 10-bit Raw, > the resolution of 1632*1224 and 3264*2448, and the bayer order of BGGR. > The hardware version also differs in some OTP regiser, > as well as PLL register setting. > > Signed-off-by: Dongchun Zhu > --- > drivers/media/i2c/ov8856.c | 624 ++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 621 insertions(+), 3 deletions(-) > Thanks for the patch! Please see my comments inline. > diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c > index cd347d6..e0610b6 100644 > --- a/drivers/media/i2c/ov8856.c > +++ b/drivers/media/i2c/ov8856.c > @@ -1,12 +1,15 @@ > // SPDX-License-Identifier: GPL-2.0 > // Copyright (c) 2019 Intel Corporation. > > +#include > #include > #include > #include > +#include > #include > #include > #include > +#include > #include > #include > #include > @@ -19,6 +22,7 @@ > #define OV8856_LINK_FREQ_180MHZ 180000000ULL > #define OV8856_SCLK 144000000ULL > #define OV8856_MCLK 19200000 > +#define OV8856_XVCLK_FREQ 24000000 > #define OV8856_DATA_LANES 4 > #define OV8856_RGB_DEPTH 10 > > @@ -29,6 +33,18 @@ > #define OV8856_MODE_STANDBY 0x00 > #define OV8856_MODE_STREAMING 0x01 > > +/* define 1B module */ > +#define OV8856_1B_MODULE 0x02 > + > +/* otp sram register */ > +#define OV8856_OTP_REG 0x700f This isn't a register. I believe the OTP read-out buffer is at 0x7000 and 0xf is the offset of the byte in the OTP that means the module revision. > +#define OV8856_OTP_REG_ONE 0x3d84 > +#define OV8856_OTP_REG_TWO 0x3d81 These registers are definitely not "ONE" and "TWO". Please use proper names as per the datasheet. > + > +/* clock register */ > +#define OV8856_CLK_REG 0x3614 > +#define OV8856_CLK_REG_1B_VAL 0x20 Same here. These don't look like the real names of the register and bit field. > + > /* vertical-timings from sensor */ > #define OV8856_REG_VTS 0x380e > #define OV8856_VTS_MAX 0x7fff > @@ -64,6 +80,14 @@ > > #define to_ov8856(_sd) container_of(_sd, struct ov8856, sd) > > +static const char * const ov8856_supply_names[] = { > + "dovdd", /* Digital I/O power */ > + "avdd", /* Analog power */ > + "dvdd", /* Digital core power */ > +}; > + > +#define OV8856_NUM_SUPPLIES ARRAY_SIZE(ov8856_supply_names) > + > enum { > OV8856_LINK_FREQ_720MBPS, > OV8856_LINK_FREQ_360MBPS, > @@ -316,6 +340,208 @@ static const struct ov8856_reg mode_3280x2464_regs[] = { > {0x5e00, 0x00} > }; > > +static const struct ov8856_reg mode_3264x2448_regs[] = { > + {0x0103, 0x01}, > + {0x0302, 0x3c}, > + {0x0303, 0x01}, > + {0x031e, 0x0c}, > + {0x3000, 0x00}, > + {0x300e, 0x00}, > + {0x3010, 0x00}, > + {0x3015, 0x84}, > + {0x3018, 0x72}, > + {0x3021, 0x23}, > + {0x3033, 0x24}, > + {0x3500, 0x00}, > + {0x3501, 0x9a}, > + {0x3502, 0x20}, > + {0x3503, 0x08}, > + {0x3505, 0x83}, > + {0x3508, 0x01}, > + {0x3509, 0x80}, > + {0x350c, 0x00}, > + {0x350d, 0x80}, > + {0x350e, 0x04}, > + {0x350f, 0x00}, > + {0x3510, 0x00}, > + {0x3511, 0x02}, > + {0x3512, 0x00}, > + {0x3600, 0x72}, > + {0x3601, 0x40}, > + {0x3602, 0x30}, > + {0x3610, 0xc5}, > + {0x3611, 0x58}, > + {0x3612, 0x5c}, > + {0x3613, 0xca}, > + {0x3614, 0x60}, > + {0x3628, 0xff}, > + {0x3629, 0xff}, > + {0x362a, 0xff}, > + {0x3633, 0x10}, > + {0x3634, 0x10}, > + {0x3635, 0x10}, > + {0x3636, 0x10}, > + {0x3663, 0x08}, > + {0x3669, 0x34}, > + {0x366d, 0x00}, > + {0x366e, 0x10}, > + {0x3706, 0x86}, > + {0x370b, 0x7e}, > + {0x3714, 0x23}, > + {0x3730, 0x12}, > + {0x3733, 0x10}, > + {0x3764, 0x00}, > + {0x3765, 0x00}, > + {0x3769, 0x62}, > + {0x376a, 0x2a}, > + {0x376b, 0x30}, > + {0x3780, 0x00}, > + {0x3781, 0x24}, > + {0x3782, 0x00}, > + {0x3783, 0x23}, > + {0x3798, 0x2f}, > + {0x37a1, 0x60}, > + {0x37a8, 0x6a}, > + {0x37ab, 0x3f}, > + {0x37c2, 0x04}, > + {0x37c3, 0xf1}, > + {0x37c9, 0x80}, > + {0x37cb, 0x16}, > + {0x37cc, 0x16}, > + {0x37cd, 0x16}, > + {0x37ce, 0x16}, > + {0x3800, 0x00}, > + {0x3801, 0x00}, > + {0x3802, 0x00}, > + {0x3803, 0x0c}, > + {0x3804, 0x0c}, > + {0x3805, 0xdf}, > + {0x3806, 0x09}, > + {0x3807, 0xa3}, > + {0x3808, 0x0c}, > + {0x3809, 0xc0}, > + {0x380a, 0x09}, > + {0x380b, 0x90}, > + {0x380c, 0x07}, > + {0x380d, 0x8c}, > + {0x380e, 0x09}, > + {0x380f, 0xb2}, > + {0x3810, 0x00}, > + {0x3811, 0x04}, > + {0x3812, 0x00}, > + {0x3813, 0x02}, > + {0x3814, 0x01}, > + {0x3815, 0x01}, > + {0x3816, 0x00}, > + {0x3817, 0x00}, > + {0x3818, 0x00}, > + {0x3819, 0x00}, > + {0x3820, 0x80}, > + {0x3821, 0x46}, > + {0x382a, 0x01}, > + {0x382b, 0x01}, > + {0x3830, 0x06}, > + {0x3836, 0x02}, > + {0x3862, 0x04}, > + {0x3863, 0x08}, > + {0x3cc0, 0x33}, > + {0x3d85, 0x17}, > + {0x3d8c, 0x73}, > + {0x3d8d, 0xde}, > + {0x4001, 0xe0}, > + {0x4003, 0x40}, > + {0x4008, 0x00}, > + {0x4009, 0x0b}, > + {0x400a, 0x00}, > + {0x400b, 0x84}, > + {0x400f, 0x80}, > + {0x4010, 0xf0}, > + {0x4011, 0xff}, > + {0x4012, 0x02}, > + {0x4013, 0x01}, > + {0x4014, 0x01}, > + {0x4015, 0x01}, > + {0x4042, 0x00}, > + {0x4043, 0x80}, > + {0x4044, 0x00}, > + {0x4045, 0x80}, > + {0x4046, 0x00}, > + {0x4047, 0x80}, > + {0x4048, 0x00}, > + {0x4049, 0x80}, > + {0x4041, 0x03}, > + {0x404c, 0x20}, > + {0x404d, 0x00}, > + {0x404e, 0x20}, > + {0x4203, 0x80}, > + {0x4307, 0x30}, > + {0x4317, 0x00}, > + {0x4502, 0x50}, > + {0x4503, 0x08}, > + {0x4601, 0x80}, > + {0x4800, 0x44}, > + {0x4816, 0x53}, > + {0x481b, 0x50}, > + {0x481f, 0x27}, > + {0x4823, 0x3c}, > + {0x482b, 0x00}, > + {0x4831, 0x66}, > + {0x4837, 0x16}, > + {0x483c, 0x0f}, > + {0x484b, 0x05}, > + {0x5000, 0x77}, > + {0x5001, 0x0a}, > + {0x5003, 0xc8}, > + {0x5004, 0x04}, > + {0x5006, 0x00}, > + {0x5007, 0x00}, > + {0x502e, 0x03}, > + {0x5030, 0x41}, > + {0x5780, 0x14}, > + {0x5781, 0x0f}, > + {0x5782, 0x44}, > + {0x5783, 0x02}, > + {0x5784, 0x01}, > + {0x5785, 0x01}, > + {0x5786, 0x00}, > + {0x5787, 0x04}, > + {0x5788, 0x02}, > + {0x5789, 0x0f}, > + {0x578a, 0xfd}, > + {0x578b, 0xf5}, > + {0x578c, 0xf5}, > + {0x578d, 0x03}, > + {0x578e, 0x08}, > + {0x578f, 0x0c}, > + {0x5790, 0x08}, > + {0x5791, 0x04}, > + {0x5792, 0x00}, > + {0x5793, 0x52}, > + {0x5794, 0xa3}, > + {0x5795, 0x02}, > + {0x5796, 0x20}, > + {0x5797, 0x20}, > + {0x5798, 0xd5}, > + {0x5799, 0xd5}, > + {0x579a, 0x00}, > + {0x579b, 0x50}, > + {0x579c, 0x00}, > + {0x579d, 0x2c}, > + {0x579e, 0x0c}, > + {0x579f, 0x40}, > + {0x57a0, 0x09}, > + {0x57a1, 0x40}, > + {0x59f8, 0x3d}, > + {0x5a08, 0x02}, > + {0x5b00, 0x02}, > + {0x5b01, 0x10}, > + {0x5b02, 0x03}, > + {0x5b03, 0xcf}, > + {0x5b05, 0x6c}, > + {0x5e00, 0x00}, > + {0x5e10, 0xfc} > +}; > + It would be better if we could find the differences between the two arrays and handle them incrementally. [snip] > +static int ov8856_update_otp_reg(struct ov8856 *ov8856) > +{ > + int ret; > + > + ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT, > + OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING); > + if (ret) > + return ret; > + > + ret = ov8856_write_reg(ov8856, OV8856_OTP_REG_ONE, > + OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY); > + if (ret) > + return ret; > + > + return ov8856_write_reg(ov8856, OV8856_OTP_REG_TWO, > + OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING); Hmm, this doesn't sound right. The OTP register doesn't have anything to do with streaming. Also we should stop streaming at the end. > +} > + > static int ov8856_set_ctrl(struct v4l2_ctrl *ctrl) > { > struct ov8856 *ov8856 = container_of(ctrl->handler, > @@ -825,7 +1302,13 @@ static void ov8856_update_pad_format(const struct ov8856_mode *mode, > { > fmt->width = mode->width; > fmt->height = mode->height; > - fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10; > + > + /* Bayer Order is determined by image resolution */ > + if (fmt->width == 3264 || fmt->width == 1632) Could we instead set the bayer order in the mode struct? > + fmt->code = MEDIA_BUS_FMT_SBGGR10_1X10; > + else > + fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10; > + > fmt->field = V4L2_FIELD_NONE; > } > > @@ -850,6 +1333,17 @@ static int ov8856_start_streaming(struct ov8856 *ov8856) > return ret; > } > > + /* update R3614 for 1B module */ What's R3614? > + if (ov8856->is_1B_module) { > + ret = ov8856_write_reg(ov8856, OV8856_CLK_REG, > + OV8856_REG_VALUE_08BIT, > + OV8856_CLK_REG_1B_VAL); > + if (ret) { > + dev_err(&client->dev, "failed to set R3614"); > + return ret; > + } > + } > + > ret = __v4l2_ctrl_handler_setup(ov8856->sd.ctrl_handler); > if (ret) > return ret; > @@ -882,6 +1376,8 @@ static int ov8856_set_stream(struct v4l2_subdev *sd, int enable) > if (ov8856->streaming == enable) > return 0; > > + dev_dbg(&client->dev, "hardware version: (%d)\n", ov8856->is_1B_module); > + > mutex_lock(&ov8856->mutex); > if (enable) { > ret = pm_runtime_get_sync(&client->dev); > @@ -908,6 +1404,54 @@ static int ov8856_set_stream(struct v4l2_subdev *sd, int enable) > return ret; > } > > +/* Calculate the delay in us by clock rate and clock cycles */ > +static inline u32 ov8856_cal_delay(u32 cycles) > +{ > + return DIV_ROUND_UP(cycles, OV8856_XVCLK_FREQ / 1000 / 1000); > +} > + > +static int __ov8856_power_on(struct ov8856 *ov8856) > +{ > + int ret; > + u32 delay_us; > + struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd); > + > + ret = clk_prepare_enable(ov8856->xvclk); > + if (ret < 0) { > + dev_err(&client->dev, "Failed to enable xvclk\n"); > + return ret; > + } > + > + gpiod_set_value_cansleep(ov8856->reset_gpio, 1); According to my datasheet, this sensor doesn't have a reset pin. The one I can see there is XSHUTDN, which I would call "n_shutdn" here. > + > + ret = regulator_bulk_enable(OV8856_NUM_SUPPLIES, ov8856->supplies); > + if (ret < 0) { > + dev_err(&client->dev, "Failed to enable regulators\n"); > + goto disable_clk; > + } > + > + gpiod_set_value_cansleep(ov8856->reset_gpio, 0); According to the datasheet, XSHUTDN should be 0 for shutdown and 1 for running. Why is it the other way around here? > + > + /* 8192 cycles prior to first SCCB transaction */ > + delay_us = ov8856_cal_delay(8192); If we pass a constant to the function and the function itself only uses constants inside, could we just define a constant delay instead? > + usleep_range(delay_us * 2, delay_us * 4); Normally one one just give some small delta here, like +/- 100 us. > + > + return 0; > + > +disable_clk: > + clk_disable_unprepare(ov8856->xvclk); > + > + return ret; > +} > + > +static void __ov8856_power_off(struct ov8856 *ov8856) > +{ > + clk_disable_unprepare(ov8856->xvclk); > + gpiod_set_value_cansleep(ov8856->reset_gpio, 1); > + > + regulator_bulk_disable(OV8856_NUM_SUPPLIES, ov8856->supplies); > +} > + > static int __maybe_unused ov8856_suspend(struct device *dev) > { > struct i2c_client *client = to_i2c_client(dev); > @@ -915,8 +1459,8 @@ static int __maybe_unused ov8856_suspend(struct device *dev) > struct ov8856 *ov8856 = to_ov8856(sd); > > mutex_lock(&ov8856->mutex); > - if (ov8856->streaming) > - ov8856_stop_streaming(ov8856); > + > + __ov8856_power_off(ov8856); This change is incorrect because it will power off even if the device was already powered off, causing reference count mismatch. The original code was okay. > > mutex_unlock(&ov8856->mutex); > > @@ -1089,6 +1633,20 @@ static int ov8856_identify_module(struct ov8856 *ov8856) > return -ENXIO; > } > > + /* set R3614 to distinguish harward versions */ hardware > + ret = ov8856_update_otp_reg(ov8856); > + if (ret) { > + dev_err(&client->dev, "failed to set otp register"); > + return ret; > + } > + > + ret = ov8856_read_reg(ov8856, OV8856_OTP_REG, > + OV8856_REG_VALUE_08BIT, &val); > + if (ret) > + return ret; > + > + ov8856->is_1B_module = (val == OV8856_1B_MODULE) ? 1 : 0; I'd rename ov8856_update_otp_reg() to ov8856_check_revision() and move the few lines above to that function too. > + > return 0; > } > > @@ -1164,11 +1722,27 @@ static int ov8856_remove(struct i2c_client *client) > media_entity_cleanup(&sd->entity); > v4l2_ctrl_handler_free(sd->ctrl_handler); > pm_runtime_disable(&client->dev); > + if (!pm_runtime_status_suspended(&client->dev)) > + __ov8856_power_off(ov8856); > + pm_runtime_set_suspended(&client->dev); > mutex_destroy(&ov8856->mutex); > > return 0; > } > > +static int ov8856_configure_regulators(struct ov8856 *ov8856) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd); > + int i; > + > + for (i = 0; i < OV8856_NUM_SUPPLIES; i++) > + ov8856->supplies[i].supply = ov8856_supply_names[i]; > + > + return devm_regulator_bulk_get(&client->dev, > + OV8856_NUM_SUPPLIES, > + ov8856->supplies); > +} There is not much value in having a dedicated function just to call one more function. Could you move back to the caller? > + > static int ov8856_probe(struct i2c_client *client) > { > struct ov8856 *ov8856; > @@ -1186,6 +1760,40 @@ static int ov8856_probe(struct i2c_client *client) > return -ENOMEM; > > v4l2_i2c_subdev_init(&ov8856->sd, client, &ov8856_subdev_ops); > + > + ov8856->xvclk = devm_clk_get(&client->dev, "xvclk"); > + if (IS_ERR(ov8856->xvclk)) { > + dev_err(&client->dev, "Failed to get xvclk\n"); > + return -EINVAL; > + } > + > + ret = clk_set_rate(ov8856->xvclk, OV8856_XVCLK_FREQ); We should get the frequency from the DT bindings. > + if (ret < 0) { > + dev_err(&client->dev, "Failed to set xvclk rate (24MHz)\n"); > + return ret; > + } > + if (clk_get_rate(ov8856->xvclk) != OV8856_XVCLK_FREQ) > + dev_warn(&client->dev, > + "xvclk mismatched, modes are based on 24MHz\n"); > + > + ov8856->reset_gpio = devm_gpiod_get(&client->dev, > + "reset", > + GPIOD_OUT_LOW); > + if (IS_ERR(ov8856->reset_gpio)) { > + dev_err(&client->dev, "Failed to get reset-gpios\n"); > + return -EINVAL; > + } > + > + ret = ov8856_configure_regulators(ov8856); > + if (ret) { > + dev_err(&client->dev, "Failed to get power regulators\n"); > + return ret; > + } > + > + ret = __ov8856_power_on(ov8856); > + if (ret) > + goto probe_error_v4l2_ctrl_handler_free; > + > ret = ov8856_identify_module(ov8856); > if (ret) { > dev_err(&client->dev, "failed to find sensor: %d", ret); > @@ -1251,11 +1859,21 @@ static const struct acpi_device_id ov8856_acpi_ids[] = { > MODULE_DEVICE_TABLE(acpi, ov8856_acpi_ids); > #endif > > +#if IS_ENABLED(CONFIG_OF) > +static const struct of_device_id ov8856_of_match[] = { > + { .compatible = "ovti,ov8856" }, > + {}, > +}; > + nit: Unnecessary blank line. Best regards, Tomasz