From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ua0-f170.google.com ([209.85.217.170]:38342 "EHLO mail-ua0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934173AbeCBPoY (ORCPT ); Fri, 2 Mar 2018 10:44:24 -0500 Received: by mail-ua0-f170.google.com with SMTP id f5so6310556uam.5 for ; Fri, 02 Mar 2018 07:44:23 -0800 (PST) Received: from mail-ua0-f182.google.com (mail-ua0-f182.google.com. [209.85.217.182]) by smtp.gmail.com with ESMTPSA id h128sm2234277vkd.7.2018.03.02.07.44.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 02 Mar 2018 07:44:21 -0800 (PST) Received: by mail-ua0-f182.google.com with SMTP id z3so6284775uae.12 for ; Fri, 02 Mar 2018 07:44:21 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1520002549-6564-1-git-send-email-andy.yeh@intel.com> References: <1520002549-6564-1-git-send-email-andy.yeh@intel.com> From: Tomasz Figa Date: Sat, 3 Mar 2018 00:43:59 +0900 Message-ID: Subject: Re: [PATCH v6] media: imx258: Add imx258 camera sensor driver To: Andy Yeh Cc: Linux Media Mailing List , Sakari Ailus , jasonx.z.chen@intel.com, Alan Chiang Content-Type: text/plain; charset="UTF-8" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Andy, Thanks for the patch. Let me post some comments inline. On Fri, Mar 2, 2018 at 11:55 PM, Andy Yeh wrote: > Add a V4L2 sub-device driver for the Sony IMX258 image sensor. > This is a camera sensor using the I2C bus for control and the > CSI-2 bus for data. > > Signed-off-by: Jason Chen > Signed-off-by: Alan Chiang > --- > since v2: > -- Update the streaming function to remove SW_STANDBY in the beginning. > -- Adjust the delay time from 1ms to 12ms before set stream-on register. > since v3: > -- fix the sd.entity to make code be compiled on the mainline kernel. > since v4: > -- Enabled AG, DG, and Exposure time control correctly. > since v5: > -- Sensor vendor provided a new setting to fix different CLK issue > -- Add one more resolution for 1048x780, used for VGA streaming > > MAINTAINERS | 7 + > drivers/media/i2c/Kconfig | 11 + > drivers/media/i2c/Makefile | 1 + > drivers/media/i2c/imx258.c | 1341 ++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 1360 insertions(+) > create mode 100644 drivers/media/i2c/imx258.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index a339bb5..9f75510 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -12646,6 +12646,13 @@ S: Maintained > F: drivers/ssb/ > F: include/linux/ssb/ > > +SONY IMX258 SENSOR DRIVER > +M: Sakari Ailus > +L: linux-media@vger.kernel.org > +T: git git://linuxtv.org/media_tree.git > +S: Maintained > +F: drivers/media/i2c/imx258.c > + > SONY IMX274 SENSOR DRIVER > M: Leon Luo > L: linux-media@vger.kernel.org > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig > index fd01842..bcd4bf1 100644 > --- a/drivers/media/i2c/Kconfig > +++ b/drivers/media/i2c/Kconfig > @@ -565,6 +565,17 @@ config VIDEO_APTINA_PLL > config VIDEO_SMIAPP_PLL > tristate > > +config VIDEO_IMX258 > + tristate "Sony IMX258 sensor support" > + depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API > + depends on MEDIA_CAMERA_SUPPORT > + ---help--- > + This is a Video4Linux2 sensor-level driver for the Sony > + IMX258 camera. > + > + To compile this driver as a module, choose M here: the > + module will be called imx258. > + > config VIDEO_IMX274 > tristate "Sony IMX274 sensor support" > depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API > diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile > index 1b62639..4bf7d00 100644 > --- a/drivers/media/i2c/Makefile > +++ b/drivers/media/i2c/Makefile > @@ -94,6 +94,7 @@ obj-$(CONFIG_VIDEO_IR_I2C) += ir-kbd-i2c.o > obj-$(CONFIG_VIDEO_ML86V7667) += ml86v7667.o > obj-$(CONFIG_VIDEO_OV2659) += ov2659.o > obj-$(CONFIG_VIDEO_TC358743) += tc358743.o > +obj-$(CONFIG_VIDEO_IMX258) += imx258.o > obj-$(CONFIG_VIDEO_IMX274) += imx274.o > > obj-$(CONFIG_SDR_MAX2175) += max2175.o > diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c > new file mode 100644 > index 0000000..0418edd > --- /dev/null > +++ b/drivers/media/i2c/imx258.c > @@ -0,0 +1,1341 @@ > +// Copyright (C) 2018 Intel Corporation > +// SPDX-License-Identifier: GPL-2.0 > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define IMX258_REG_VALUE_08BIT 1 > +#define IMX258_REG_VALUE_16BIT 2 > +#define IMX258_REG_VALUE_24BIT 3 Is there any need for these macros? Respective functions could just take the number of bytes as the argument directly. > + > +#define IMX258_REG_MODE_SELECT 0x0100 > +#define IMX258_MODE_STANDBY 0x00 > +#define IMX258_MODE_STREAMING 0x01 > + > +/* Chip ID */ > +#define IMX258_REG_CHIP_ID 0x0016 > +#define IMX258_CHIP_ID 0x0258 > + > +/* V_TIMING internal */ > +#define IMX258_REG_VTS 0x0340 > +#define IMX258_VTS_30FPS 0x0c98 > +#define IMX258_VTS_MAX 0xffff > + > +/*Frame Length Line*/ > +#define IMX258_FLL_MIN 0x08a6 > +#define IMX258_FLL_MAX 0xffff > +#define IMX258_FLL_STEP 1 > +#define IMX258_FLL_DEFAULT 0x0c98 > + > +/* HBLANK control - read only */ > +#define IMX258_PPL_650MHZ 5352 > +#define IMX258_PPL_325MHZ 2676 > + > +/* Exposure control */ > +#define IMX258_REG_EXPOSURE 0x0202 > +#define IMX258_EXPOSURE_MIN 4 > +#define IMX258_EXPOSURE_STEP 1 > +#define IMX258_EXPOSURE_DEFAULT 0x640 > +#define IMX258_EXPOSURE_MAX 65535 > + > +/* Analog gain control */ > +#define IMX258_REG_ANALOG_GAIN 0x0204 > +#define IMX258_ANA_GAIN_MIN 0 > +#define IMX258_ANA_GAIN_MAX 0x1fff > +#define IMX258_ANA_GAIN_STEP 1 > +#define IMX258_ANA_GAIN_DEFAULT 0x0 > + > +/* Digital gain control */ > +#define IMX258_REG_GR_DIGITAL_GAIN 0x020e > +#define IMX258_REG_R_DIGITAL_GAIN 0x0210 > +#define IMX258_REG_B_DIGITAL_GAIN 0x0212 > +#define IMX258_REG_GB_DIGITAL_GAIN 0x0214 > +#define IMX258_DGTL_GAIN_MIN 0 > +#define IMX258_DGTL_GAIN_MAX 4096 /* Max = 0xFFF */ > +#define IMX258_DGTL_GAIN_DEFAULT 1024 > +#define IMX258_DGTL_GAIN_STEP 1 > + > +/* Orientation */ > +#define REG_MIRROR_FLIP_CONTROL 0x0101 > +#define REG_CONFIG_MIRROR_FLIP 0x03 > + > +struct imx258_reg { > + u16 address; > + u8 val; > +}; > + > +struct imx258_reg_list { > + u32 num_of_regs; > + const struct imx258_reg *regs; > +}; > + > +/* Link frequency config */ > +struct imx258_link_freq_config { > + u32 pixels_per_line; > + > + /* PLL registers for this link frequency */ > + struct imx258_reg_list reg_list; > +}; > + > +/* Mode : resolution and related config&values */ > +struct imx258_mode { > + /* Frame width */ > + u32 width; > + /* Frame height */ > + u32 height; > + > + /* V-timing */ > + u32 vts_def; > + u32 vts_min; > + > + /* Index of Link frequency config to be used */ > + u32 link_freq_index; > + /* Default register values */ > + struct imx258_reg_list reg_list; > +}; > + > +/* 4208x3118 needs 1300Mbps/lane, 4 lanes */ > +static const struct imx258_reg mipi_data_rate_1300mbps[] = { > + {0x0301, 0x05}, CodingStyle: Spaces inside the braces and lowercase hex, e.g. { 0x1234, 0xabcd }, [snip] > + {0x951B, 0x50}, > + {0x3030, 0x00}, > + {0x3032, 0x00}, > + {0x0220, 0x00}, > +}; nit: Blank line would be nice here. > +static const char * const imx258_test_pattern_menu[] = { > + "Disabled", > + "Vertical Color Bar Type 1", > + "Vertical Color Bar Type 2", > + "Vertical Color Bar Type 3", > + "Vertical Color Bar Type 4" > +}; > + > +/* Configurations for supported link frequencies */ > +#define IMX258_LINK_FREQ_650MHZ 649600000ULL > +#define IMX258_LINK_FREQ_325MHZ 324800000ULL > + > +/* > + * pixel_rate = link_freq * data-rate * nr_of_lanes / bits_per_sample > + * data rate => double data rate; number of lanes => 4; bits per pixel => 10 > + */ > +static u64 link_freq_to_pixel_rate(u64 f) > +{ > + f *= 2 * 4; > + do_div(f, 10); > + > + return f; > +} > + > +/* Menu items for LINK_FREQ V4L2 control */ > +static const s64 link_freq_menu_items[] = { > + IMX258_LINK_FREQ_650MHZ, > + IMX258_LINK_FREQ_325MHZ, > +}; > + > +/* Link frequency configs */ > +static const struct imx258_link_freq_config link_freq_configs[] = { > + { > + .pixels_per_line = IMX258_PPL_650MHZ, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mipi_data_rate_1300mbps), > + .regs = mipi_data_rate_1300mbps, > + } > + }, > + { > + .pixels_per_line = IMX258_PPL_325MHZ, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mipi_data_rate_650mbps), > + .regs = mipi_data_rate_650mbps, > + } > + }, Could you define an enum for the entries here nd use explicit indexing? e.g. enum { IMX258_LINK_FREQ_1300MBPS, IMX258_LINK_FREQ_650MBPS, }; static const struct imx258_link_freq_config link_freq_configs[] = { [IMX258_LINK_FREQ_1300MBPS] = { ... }, [IMX258_LINK_FREQ_650MBPS] = { ... }, }; and then... (See below.) > +}; > + > +/* Mode configs */ > +static const struct imx258_mode supported_modes[] = { > + { > + .width = 4208, > + .height = 3118, > + .vts_def = IMX258_VTS_30FPS, > + .vts_min = IMX258_VTS_30FPS, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mode_4208x3118_regs), > + .regs = mode_4208x3118_regs, > + }, > + .link_freq_index = 0, ...use the indices defined above here. This way we have an explicit link between both arrays and it's not possible to accidentally break it. [snip] > + > + /* Mutex for serialized access */ > + struct mutex mutex; Please document what needs to be serialized. > + > + /* Streaming on/off */ > + bool streaming; > +}; > + > +#define to_imx258(_sd) container_of(_sd, struct imx258, sd) Please use a static inline for compiler type safety. > + > +/* Read registers up to 4 at a time */ > +static int imx258_read_reg(struct imx258 *imx258, u16 reg, u32 len, u32 *val) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); > + struct i2c_msg msgs[2]; > + u8 *data_be_p; > + int ret; > + u32 data_be = 0; > + u16 reg_addr_be = cpu_to_be16(reg); > + > + if (len > 4) > + return -EINVAL; > + > + data_be_p = (u8 *)&data_be; > + /* Write register address */ > + msgs[0].addr = client->addr; > + msgs[0].flags = 0; > + msgs[0].len = 2; > + msgs[0].buf = (u8 *)®_addr_be; No need for this big endian and pointer cast magic. Let's make this a bit more readable: u8 addr_buf[2] = { reg >> 8, reg & 0xff }; [...] msgs[0].len = ARRAY_SIZE(addr_buf); msgs[0].buf = addr_buf; > + > + /* Read data from register */ > + msgs[1].addr = client->addr; > + msgs[1].flags = I2C_M_RD; > + msgs[1].len = len; > + msgs[1].buf = &data_be_p[4 - len]; u8 data_buf[4] = { 0, }; [...] msgs[1].buf = &data_buf[4 - len]; > + > + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); > + if (ret != ARRAY_SIZE(msgs)) > + return -EIO; > + > + *val = be32_to_cpu(data_be); *val = get_unaligned_be32(data_buf); > + > + return 0; > +} > + > +/* Write registers up to 4 at a time */ > +static int imx258_write_reg(struct imx258 *imx258, u16 reg, u32 len, u32 val) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); > + int buf_i, val_i; > + u8 buf[6], *val_p; > + > + if (len > 4) > + return -EINVAL; > + > + buf[0] = reg >> 8; > + buf[1] = reg & 0xff; > + > + val = cpu_to_be32(val); > + val_p = (u8 *)&val; > + buf_i = 2; > + val_i = 4 - len; > + > + while (val_i < 4) > + buf[buf_i++] = val_p[val_i++]; Similar thing here. The above 7 lines are the same as: put_unaligned_be32(val << (8 * (4 - len)), buf); > + > + if (i2c_master_send(client, buf, len + 2) != len + 2) > + return -EIO; > + > + return 0; > +} > + > +/* Write a list of registers */ > +static int imx258_write_regs(struct imx258 *imx258, > + const struct imx258_reg *regs, u32 len) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); > + int ret; > + u32 i; > + > + for (i = 0; i < len; i++) { > + ret = imx258_write_reg(imx258, regs[i].address, 1, > + regs[i].val); > + if (ret) { > + dev_err_ratelimited( > + &client->dev, > + "Failed to write reg 0x%4.4x. error = %d\n", > + regs[i].address, ret); > + > + return ret; > + } > + } > + > + return 0; > +} > + > +static int imx258_write_reg_list(struct imx258 *imx258, > + const struct imx258_reg_list *r_list) > +{ > + return imx258_write_regs(imx258, r_list->regs, r_list->num_of_regs); This is the only place where imx258_write_regs() is used. Is there any need to make it a separate function? > +} > + > +/* Open sub-device */ > +static int imx258_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) > +{ > + struct v4l2_mbus_framefmt *try_fmt = > + v4l2_subdev_get_try_format(sd, fh->pad, 0); > + > + /* Initialize try_fmt */ > + try_fmt->width = supported_modes[0].width; > + try_fmt->height = supported_modes[0].height; > + try_fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10; > + try_fmt->field = V4L2_FIELD_NONE; > + > + return 0; > +} > + > +static int imx258_i2c_write_reg_ext(struct imx258 *imx258, u16 reg, > + u32 len, u32 val) > +{ > + u32 val_d, val_d2; > + int ret; > + u32 mask = 0xff; > + > + val_d = (val & ~mask) >> 8; > + val_d2 = val & mask; > + > + ret = imx258_write_reg(imx258, reg, len/2, val_d); > + ret = imx258_write_reg(imx258, reg+1, len/2, val_d2); > + > + if (ret) > + return ret; > + return 0; > +} What is this function for? I don't see why imx258_write_reg() couldn't be called directly... > + > +static int imx258_update_digital_gain(struct imx258 *imx258, u32 len, u32 val) > +{ > + int ret; > + > + ret = imx258_i2c_write_reg_ext(imx258, IMX258_REG_GR_DIGITAL_GAIN, > + IMX258_REG_VALUE_16BIT, > + val); > + ret |= imx258_i2c_write_reg_ext(imx258, IMX258_REG_GB_DIGITAL_GAIN, > + IMX258_REG_VALUE_16BIT, > + val); > + ret |= imx258_i2c_write_reg_ext(imx258, IMX258_REG_R_DIGITAL_GAIN, > + IMX258_REG_VALUE_16BIT, > + val); > + ret |= imx258_i2c_write_reg_ext(imx258, IMX258_REG_B_DIGITAL_GAIN, > + IMX258_REG_VALUE_16BIT, > + val); Please don't do bitwise OR on return values. If two or more of the above calls return different non-zero values, the resulting value will make no sense. > + if (ret) > + return ret; > + return 0; > +} > + > +static int imx258_set_ctrl(struct v4l2_ctrl *ctrl) > +{ > + struct imx258 *imx258 = > + container_of(ctrl->handler, struct imx258, ctrl_handler); > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); > + int ret = 0; > + /* > + * Applying V4L2 control value only happens > + * when power is up for streaming > + */ > + if (pm_runtime_get_if_in_use(&client->dev) <= 0) > + return 0; I thought we decided to fix this to handle disabled runtime PM properly. > + > + switch (ctrl->id) { > + case V4L2_CID_ANALOGUE_GAIN: > + ret = imx258_i2c_write_reg_ext(imx258, IMX258_REG_ANALOG_GAIN, > + IMX258_REG_VALUE_16BIT, > + ctrl->val); > + break; > + case V4L2_CID_EXPOSURE: > + ret = imx258_i2c_write_reg_ext(imx258, IMX258_REG_EXPOSURE, > + IMX258_REG_VALUE_16BIT, > + ctrl->val); > + break; > + case V4L2_CID_DIGITAL_GAIN: > + ret = imx258_update_digital_gain(imx258, IMX258_REG_VALUE_16BIT, > + ctrl->val); > + break; > + default: > + dev_info(&client->dev, > + "ctrl(id:0x%x,val:0x%x) is not handled\n", > + ctrl->id, ctrl->val); dev_err() and set ret to an error. > + break; > + } > + > + pm_runtime_put(&client->dev); > + > + return ret; > +} [snip] > +/* Start streaming */ > +static int imx258_start_streaming(struct imx258 *imx258) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); > + const struct imx258_reg_list *reg_list; > + int ret, link_freq_index; > + > + /* Setup PLL */ > + link_freq_index = imx258->cur_mode->link_freq_index; > + reg_list = &link_freq_configs[link_freq_index].reg_list; > + ret = imx258_write_reg_list(imx258, reg_list); > + if (ret) { > + dev_err(&client->dev, "%s failed to set plls\n", __func__); > + return ret; > + } > + > + /* Apply default values of current mode */ > + reg_list = &imx258->cur_mode->reg_list; > + ret = imx258_write_reg_list(imx258, reg_list); > + if (ret) { > + dev_err(&client->dev, "%s failed to set mode\n", __func__); > + return ret; > + } > + > + /* Set Orientation be 180 degree */ > + ret = imx258_write_reg(imx258, REG_MIRROR_FLIP_CONTROL, > + IMX258_REG_VALUE_08BIT, REG_CONFIG_MIRROR_FLIP); > + if (ret) { > + dev_err(&client->dev, "%s failed to set orientation\n", > + __func__); > + return ret; > + } > + > + /* Apply customized values from user */ > + ret = __v4l2_ctrl_handler_setup(imx258->sd.ctrl_handler); > + if (ret) > + return ret; > + > + usleep_range(12000, 13000); Please add a comment explaining what this usleep_range() is waiting for. > + > + /* set stream on register */ > + return imx258_write_reg(imx258, IMX258_REG_MODE_SELECT, > + IMX258_REG_VALUE_08BIT, > + IMX258_MODE_STREAMING); > +} [snip] > +/* Initialize control handlers */ > +static int imx258_init_controls(struct imx258 *imx258) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd); > + struct v4l2_ctrl_handler *ctrl_hdlr; > + s64 exposure_max; > + s64 vblank_def; > + s64 vblank_min; > + s64 pixel_rate_min; > + s64 pixel_rate_max; > + int ret; > + > + ctrl_hdlr = &imx258->ctrl_handler; > + ret = v4l2_ctrl_handler_init(ctrl_hdlr, 8); > + if (ret) Missing error message. > + return ret; > + > + mutex_init(&imx258->mutex); > + ctrl_hdlr->lock = &imx258->mutex; > + imx258->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr, > + &imx258_ctrl_ops, > + V4L2_CID_LINK_FREQ, > + ARRAY_SIZE(link_freq_menu_items) - 1, > + 0, > + link_freq_menu_items); > + > + if (!imx258->link_freq) { > + ret = -EINVAL; Missing error message. > + goto error; > + } > + > + imx258->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY; > + > + pixel_rate_max = link_freq_to_pixel_rate(link_freq_menu_items[0]); > + pixel_rate_min = link_freq_to_pixel_rate(link_freq_menu_items[1]); > + /* By default, PIXEL_RATE is read only */ > + imx258->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops, > + V4L2_CID_PIXEL_RATE, > + pixel_rate_min, pixel_rate_max, > + 1, pixel_rate_max); > + > + > + vblank_def = imx258->cur_mode->vts_def - imx258->cur_mode->height; > + vblank_min = imx258->cur_mode->vts_min - imx258->cur_mode->height; > + imx258->vblank = v4l2_ctrl_new_std( > + ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_VBLANK, > + vblank_min, > + IMX258_VTS_MAX - imx258->cur_mode->height, 1, > + vblank_def); > + > + imx258->hblank = v4l2_ctrl_new_std( > + ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_HBLANK, > + IMX258_PPL_650MHZ - imx258->cur_mode->width, > + IMX258_PPL_650MHZ - imx258->cur_mode->width, > + 1, > + IMX258_PPL_650MHZ - imx258->cur_mode->width); > + > + if (!imx258->hblank) { > + ret = -EINVAL; > + goto error; > + } Why checking hblank, but not other controls? I think in this case just the general check for ctrl_hdlr->error should be enough. > + > + imx258->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY; > + > + exposure_max = imx258->cur_mode->vts_def - 8; > + imx258->exposure = v4l2_ctrl_new_std( > + ctrl_hdlr, &imx258_ctrl_ops, > + V4L2_CID_EXPOSURE, IMX258_EXPOSURE_MIN, > + IMX258_EXPOSURE_MAX, IMX258_EXPOSURE_STEP, > + IMX258_EXPOSURE_DEFAULT); > + > + v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_ANALOGUE_GAIN, > + IMX258_ANA_GAIN_MIN, IMX258_ANA_GAIN_MAX, > + IMX258_ANA_GAIN_STEP, IMX258_ANA_GAIN_DEFAULT); > + > + v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_DIGITAL_GAIN, > + IMX258_DGTL_GAIN_MIN, IMX258_DGTL_GAIN_MAX, > + IMX258_DGTL_GAIN_STEP, IMX258_DGTL_GAIN_DEFAULT); > + > + v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &imx258_ctrl_ops, > + V4L2_CID_TEST_PATTERN, > + ARRAY_SIZE(imx258_test_pattern_menu) - 1, > + 0, 0, imx258_test_pattern_menu); > + > + if (ctrl_hdlr->error) { > + ret = ctrl_hdlr->error; > + dev_err(&client->dev, "%s control init failed (%d)\n", > + __func__, ret); > + goto error; > + } > + > + imx258->sd.ctrl_handler = ctrl_hdlr; > + > + return 0; > + > +error: > + v4l2_ctrl_handler_free(ctrl_hdlr); > + mutex_destroy(&imx258->mutex); > + > + return ret; > +} > + > +static void imx258_free_controls(struct imx258 *imx258) > +{ > + v4l2_ctrl_handler_free(imx258->sd.ctrl_handler); > + mutex_destroy(&imx258->mutex); > +} > + > +static int imx258_probe(struct i2c_client *client) > +{ > + struct imx258 *imx258; > + int ret; > + u32 val = 0; > + > + device_property_read_u32(&client->dev, "clock-frequency", &val); > + if (val != 19200000) Would be nice to print some error. > + return -EINVAL; > + > + imx258 = devm_kzalloc(&client->dev, sizeof(*imx258), GFP_KERNEL); > + if (!imx258) > + return -ENOMEM; > + > + /* Initialize subdev */ > + v4l2_i2c_subdev_init(&imx258->sd, client, &imx258_subdev_ops); > + > + /* Check module identity */ > + ret = imx258_identify_module(imx258); > + if (ret) > + return ret; > + > + /* Set default mode to max resolution */ > + imx258->cur_mode = &supported_modes[0]; > + > + ret = imx258_init_controls(imx258); > + if (ret) > + return ret; > + > + /* Initialize subdev */ > + imx258->sd.internal_ops = &imx258_internal_ops; > + imx258->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE; > + imx258->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR; > + > + /* Initialize source pad */ > + imx258->pad.flags = MEDIA_PAD_FL_SOURCE; > + > + ret = media_entity_pads_init(&imx258->sd.entity, 1, &imx258->pad); > + if (ret) { > + dev_err(&client->dev, "%s failed:%d\n", __func__, ret); This isn't a very useful error message. "media_entity_pads_init() failed: %d\n" would make more sense. Best regards, Tomasz