Hi Ping-chung, On Mon, Jul 30, 2018 at 6:19 PM Ping-chung Chen <ping-chung.chen@xxxxxxxxx> wrote: > > From: "Chen, Ping-chung" <ping-chung.chen@xxxxxxxxx> > > Add a V4L2 sub-device driver for the Sony IMX208 image sensor. > This is a camera sensor using the I2C bus for control and the > CSI-2 bus for data. > Please see my comments inline. [snip] > diff --git a/drivers/media/i2c/imx208.c b/drivers/media/i2c/imx208.c > new file mode 100644 > index 0000000..5adfb79 > --- /dev/null > +++ b/drivers/media/i2c/imx208.c > @@ -0,0 +1,984 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright (C) 2018 Intel Corporation > + > +#include <linux/acpi.h> > +#include <linux/delay.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/pm_runtime.h> > +#include <media/v4l2-ctrls.h> > +#include <media/v4l2-device.h> > +#include <asm/unaligned.h> > + > +#define IMX208_REG_VALUE_08BIT 1 > +#define IMX208_REG_VALUE_16BIT 2 We don't need to define these. It's obvious that 8 bits is 1 byte and 16 bits are 2 bytes. > + > +#define IMX208_REG_MODE_SELECT 0x0100 > +#define IMX208_MODE_STANDBY 0x00 > +#define IMX208_MODE_STREAMING 0x01 [snip] > +/* Test Pattern Control */ > +#define IMX208_REG_TEST_PATTERN_MODE 0x0600 > +#define IMX208_TEST_PATTERN_DISABLE 0 > +#define IMX208_TEST_PATTERN_SOLID_COLOR 1 > +#define IMX208_TEST_PATTERN_COLOR_BARS 2 > +#define IMX208_TEST_PATTERN_GREY_COLOR 3 > +#define IMX208_TEST_PATTERN_PN9 4 Please use hexadecimal notation for register values (as already done below). > +#define IMX208_TEST_PATTERN_FIX_1 0x100 > +#define IMX208_TEST_PATTERN_FIX_2 0x101 > +#define IMX208_TEST_PATTERN_FIX_3 0x102 > +#define IMX208_TEST_PATTERN_FIX_4 0x103 > +#define IMX208_TEST_PATTERN_FIX_5 0x104 > +#define IMX208_TEST_PATTERN_FIX_6 0x105 [snip] > +static const int imx208_test_pattern_val[] = { > + IMX208_TEST_PATTERN_DISABLE, > + IMX208_TEST_PATTERN_SOLID_COLOR, > + IMX208_TEST_PATTERN_COLOR_BARS, > + IMX208_TEST_PATTERN_GREY_COLOR, > + IMX208_TEST_PATTERN_PN9, > + IMX208_TEST_PATTERN_FIX_1, > + IMX208_TEST_PATTERN_FIX_2, > + IMX208_TEST_PATTERN_FIX_3, > + IMX208_TEST_PATTERN_FIX_4, > + IMX208_TEST_PATTERN_FIX_5, > + IMX208_TEST_PATTERN_FIX_6, > +}; > + > +/* Configurations for supported link frequencies */ > +#define IMX208_LINK_FREQ_384MHZ 384000000ULL > +#define IMX208_LINK_FREQ_96MHZ 96000000ULL nit: If we really need defines for these, then at least they should be somehow useful, e.g. #define MHZ (1000*1000ULL) #define IMX208_LINK_FREQ_384MHZ (384ULL * MHZ) This at least makes it easy to see that there are no mistakes in the number, e.g. wrong number of zeroes. > + > +enum { > + IMX208_LINK_FREQ_384MHZ_INDEX, > + IMX208_LINK_FREQ_96MHZ_INDEX, > +}; > + > +/* > + * pixel_rate = link_freq * data-rate * nr_of_lanes / bits_per_sample > + * data rate => double data rate; number of lanes => 2; bits per pixel => 10 > + */ > +static u64 link_freq_to_pixel_rate(u64 f) > +{ > + f *= 2 * 2; > + do_div(f, 10); Please add macros for those magic numbers. > + > + return f; > +} > + > +/* Menu items for LINK_FREQ V4L2 control */ > +static const s64 link_freq_menu_items[] = { > + IMX208_LINK_FREQ_384MHZ, > + IMX208_LINK_FREQ_96MHZ, Since we have an enum already, please use it for explicit indices, to ensure things are consistent and actually easier to read, i.e. [IMX208_LINK_FREQ_384MHZ_INDEX] = IMX208_LINK_FREQ_384MHZ, > +}; > + > +/* Link frequency configs */ > +static const struct imx208_link_freq_config link_freq_configs[] = { > + { Explicit indices, i.e. [IMX208_LINK_FREQ_384MHZ_INDEX] = { > + .pixels_per_line = IMX208_PPL_384MHZ, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mipi_data_rate), > + .regs = mipi_data_rate, > + } > + }, > + { Ditto. > + .pixels_per_line = IMX208_PPL_96MHZ, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mipi_data_rate), > + .regs = mipi_data_rate, How comes that both link frequencies have the same register values for MIPI data rate? > + } > + }, > +}; > + > +/* Mode configs */ > +static const struct imx208_mode supported_modes[] = { > + { > + .width = 1936, > + .height = 1096, > + .vts_def = IMX208_VTS_60FPS, > + .vts_min = IMX208_VTS_60FPS_MIN, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mode_1936x1096_60fps_regs), > + .regs = mode_1936x1096_60fps_regs, > + }, > + .link_freq_index = 0, Please use the index that was defined before - IMX208_LINK_FREQ_384MHZ_INDEX. > + }, > + { > + .width = 968, > + .height = 548, > + .vts_def = IMX208_VTS_BINNING, > + .vts_min = IMX208_VTS_BINNING_MIN, > + .reg_list = { > + .num_of_regs = ARRAY_SIZE(mode_968_548_60fps_regs), > + .regs = mode_968_548_60fps_regs, > + }, > + .link_freq_index = IMX208_LINK_FREQ_96MHZ_INDEX, > + }, > +}; > + > +struct imx208 { > + struct v4l2_subdev sd; > + struct media_pad pad; > + > + struct v4l2_ctrl_handler ctrl_handler; > + /* V4L2 Controls */ > + struct v4l2_ctrl *link_freq; > + struct v4l2_ctrl *pixel_rate; > + struct v4l2_ctrl *vblank; > + struct v4l2_ctrl *hblank; > + struct v4l2_ctrl *vflip; > + struct v4l2_ctrl *hflip; > + > + /* Current mode */ > + const struct imx208_mode *cur_mode; > + > + /* Mutex for serialized access */ The comment doesn't say access to what is serialized. > + struct mutex imx208_mx; > + > + /* Streaming on/off */ > + bool streaming; > +}; > + > +static inline struct imx208 *to_imx208(struct v4l2_subdev *_sd) > +{ > + return container_of(_sd, struct imx208, sd); > +} > + > +/* Get bayer order based on flip setting. */ > +static __u32 imx208_get_format_code(struct imx208 *imx208) Why not just "u32"? > +{ > + /* > + * Only one bayer order is supported. > + * It depends on the flip settings. > + */ > + static const __u32 codes[2][2] = { Ditto. > + { MEDIA_BUS_FMT_SRGGB10_1X10, MEDIA_BUS_FMT_SGRBG10_1X10, }, > + { MEDIA_BUS_FMT_SGBRG10_1X10, MEDIA_BUS_FMT_SBGGR10_1X10, }, > + }; > + > + return codes[imx208->vflip->val][imx208->hflip->val]; > +} > + > +/* Read registers up to 2 at a time */ The function seems to be handling up to 4 (which I guess is okay, but the comment is off). > +static int imx208_read_reg(struct imx208 *imx208, u16 reg, u32 len, u32 *val) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd); > + struct i2c_msg msgs[2]; > + u8 addr_buf[2] = { reg >> 8, reg & 0xff }; > + u8 data_buf[4] = { 0, }; > + int ret; > + > + if (len > 4) > + return -EINVAL; > + > + /* Write register address */ > + msgs[0].addr = client->addr; > + msgs[0].flags = 0; > + 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_buf[4 - len]; > + > + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); > + if (ret != ARRAY_SIZE(msgs)) > + return -EIO; > + > + *val = get_unaligned_be32(data_buf); > + > + return 0; > +} [snip] > +static int imx208_set_ctrl(struct v4l2_ctrl *ctrl) > +{ > + struct imx208 *imx208 = > + container_of(ctrl->handler, struct imx208, ctrl_handler); > + struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd); > + int ret; > + > + /* > + * Applying V4L2 control value only happens > + * when power is up for streaming > + */ > + if (pm_runtime_get_if_in_use(&client->dev) <= 0) This is buggy, because it won't handle the case of runtime PM disabled in kernel config. The check should be (!pm_runtime_get_if_in_use(&client->dev)). > + return 0; > + > + switch (ctrl->id) { > + case V4L2_CID_ANALOGUE_GAIN: > + ret = imx208_write_reg(imx208, IMX208_REG_ANALOG_GAIN, > + IMX208_REG_VALUE_16BIT, ctrl->val); > + break; > + case V4L2_CID_EXPOSURE: > + ret = imx208_write_reg(imx208, IMX208_REG_EXPOSURE, > + IMX208_REG_VALUE_16BIT, ctrl->val); > + break; > + case V4L2_CID_DIGITAL_GAIN: > + ret = imx208_update_digital_gain(imx208, IMX208_REG_VALUE_16BIT, > + ctrl->val); nit: The line looks misaligned. > + break; > + case V4L2_CID_VBLANK: > + /* Update VTS that meets expected vertical blanking */ > + ret = imx208_write_reg(imx208, IMX208_REG_VTS, > + IMX208_REG_VALUE_16BIT, > + imx208->cur_mode->height + ctrl->val); > + break; > + case V4L2_CID_TEST_PATTERN: > + ret = imx208_write_reg(imx208, IMX208_REG_TEST_PATTERN_MODE, > + IMX208_REG_VALUE_16BIT, > + imx208_test_pattern_val[ctrl->val]); > + break; > + case V4L2_CID_HFLIP: > + case V4L2_CID_VFLIP: > + ret = imx208_write_reg(imx208, IMX208_REG_ORIENTATION_CONTROL, > + IMX208_REG_VALUE_08BIT, > + imx208->hflip->val | > + imx208->vflip->val << 1); > + break; > + default: > + ret = -EINVAL; > + dev_info(&client->dev, This is an error, so dev_err(). > + "ctrl(id:0x%x,val:0x%x) is not handled\n", > + ctrl->id, ctrl->val); > + break; > + } > + > + pm_runtime_put(&client->dev); > + > + return ret; > +} [snip] > +/* Initialize control handlers */ > +static int imx208_init_controls(struct imx208 *imx208) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd); > + struct v4l2_ctrl_handler *ctrl_hdlr = &imx208->ctrl_handler; > + s64 exposure_max; > + s64 vblank_def; > + s64 vblank_min; > + s64 pixel_rate_min; > + s64 pixel_rate_max; > + int ret; > + > + ret = v4l2_ctrl_handler_init(ctrl_hdlr, 8); > + if (ret) > + return ret; > + > + mutex_init(&imx208->imx208_mx); > + ctrl_hdlr->lock = &imx208->imx208_mx; > + imx208->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr, > + &imx208_ctrl_ops, > + V4L2_CID_LINK_FREQ, > + ARRAY_SIZE(link_freq_menu_items) - 1, > + 0, > + link_freq_menu_items); > + > + if (imx208->link_freq) > + imx208->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]); Please replace [1] with [ARRAY_SIZE(link_freq_menu_items) - 1]. Also please add a comment saying that link_freq_menu_items[] must be sorted by link freq descending, above the array. > + /* By default, PIXEL_RATE is read only */ > + imx208->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx208_ctrl_ops, > + V4L2_CID_PIXEL_RATE, > + pixel_rate_min, pixel_rate_max, > + 1, pixel_rate_max); > + > + vblank_def = imx208->cur_mode->vts_def - imx208->cur_mode->height; > + vblank_min = imx208->cur_mode->vts_min - imx208->cur_mode->height; > + imx208->vblank = v4l2_ctrl_new_std( > + ctrl_hdlr, &imx208_ctrl_ops, V4L2_CID_VBLANK, > + vblank_min, > + IMX208_VTS_MAX - imx208->cur_mode->height, 1, > + vblank_def); > + > + imx208->hblank = v4l2_ctrl_new_std( > + ctrl_hdlr, &imx208_ctrl_ops, V4L2_CID_HBLANK, > + IMX208_PPL_384MHZ - imx208->cur_mode->width, > + IMX208_PPL_384MHZ - imx208->cur_mode->width, > + 1, > + IMX208_PPL_384MHZ - imx208->cur_mode->width); > + > + if (imx208->hblank) > + imx208->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY; > + > + exposure_max = imx208->cur_mode->vts_def - 8; > + v4l2_ctrl_new_std(ctrl_hdlr, &imx208_ctrl_ops, V4L2_CID_EXPOSURE, > + IMX208_EXPOSURE_MIN, IMX208_EXPOSURE_MAX, > + IMX208_EXPOSURE_STEP, IMX208_EXPOSURE_DEFAULT); > + > + imx208->hflip = v4l2_ctrl_new_std(ctrl_hdlr, &imx208_ctrl_ops, > + V4L2_CID_HFLIP, 0, 1, 1, 0); > + imx208->vflip = v4l2_ctrl_new_std(ctrl_hdlr, &imx208_ctrl_ops, > + V4L2_CID_VFLIP, 0, 1, 1, 0); > + > + v4l2_ctrl_new_std(ctrl_hdlr, &imx208_ctrl_ops, V4L2_CID_ANALOGUE_GAIN, > + IMX208_ANA_GAIN_MIN, IMX208_ANA_GAIN_MAX, > + IMX208_ANA_GAIN_STEP, IMX208_ANA_GAIN_DEFAULT); > + > + v4l2_ctrl_new_std(ctrl_hdlr, &imx208_ctrl_ops, V4L2_CID_DIGITAL_GAIN, > + IMX208_DGTL_GAIN_MIN, IMX208_DGTL_GAIN_MAX, > + IMX208_DGTL_GAIN_STEP, > + IMX208_DGTL_GAIN_DEFAULT); > + > + v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &imx208_ctrl_ops, > + V4L2_CID_TEST_PATTERN, > + ARRAY_SIZE(imx208_test_pattern_menu) - 1, > + 0, 0, imx208_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; > + } > + > + imx208->sd.ctrl_handler = ctrl_hdlr; > + > + return 0; > + > +error: > + v4l2_ctrl_handler_free(ctrl_hdlr); > + mutex_destroy(&imx208->imx208_mx); > + > + return ret; > +} > + > +static void imx208_free_controls(struct imx208 *imx208) > +{ > + v4l2_ctrl_handler_free(imx208->sd.ctrl_handler); > + mutex_destroy(&imx208->imx208_mx); This mutex is not related to controls. Please just paste the 2 lines above to where they are called, as this function adds more lines than it saves. > +} > + > +static int imx208_probe(struct i2c_client *client) > +{ > + struct imx208 *imx208; > + int ret; > + u32 val = 0; > + > + device_property_read_u32(&client->dev, "clock-frequency", &val); > + if (val != 19200000) Please print an error message, e.g. dev_err(&client->dev, "Unsupported value of 'clock-frequency' (%u). Expected 19200000.\n", val); P.S. Please use my @chromium.org address in the future, if posting upstream. Best regards, Tomasz