// SPDX-License-Identifier: GPL-2.0
/*
 * video-i2c.c - Support for I2C transport video devices
 *
 * Copyright (C) 2018 Matt Ranostay <matt.ranostay@konsulko.com>
 *
 * Supported:
 * - Panasonic AMG88xx Grid-Eye Sensors
 * - Melexis MLX90640 Thermal Cameras
 */

#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/freezer.h>
#include <linux/hwmon.h>
#include <linux/kthread.h>
#include <linux/i2c.h>
#include <linux/list.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/nvmem-provider.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <media/v4l2-common.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-vmalloc.h>

#define VIDEO_I2C_DRIVER        "video-i2c"

/* Power control register */
#define AMG88XX_REG_PCTL        0x00
#define AMG88XX_PCTL_NORMAL             0x00
#define AMG88XX_PCTL_SLEEP              0x10

/* Reset register */
#define AMG88XX_REG_RST         0x01
#define AMG88XX_RST_FLAG                0x30
#define AMG88XX_RST_INIT                0x3f

/* Frame rate register */
#define AMG88XX_REG_FPSC        0x02
#define AMG88XX_FPSC_1FPS               BIT(0)

/* Thermistor register */
#define AMG88XX_REG_TTHL        0x0e

/* Temperature register */
#define AMG88XX_REG_T01L        0x80

/* RAM */
#define MLX90640_RAM_START_ADDR         0x0400

/* EEPROM */
#define MLX90640_EEPROM_START_ADDR      0x2400

/* Control register */
#define MLX90640_REG_CTL1               0x800d
#define MLX90640_REG_CTL1_MASK          GENMASK(9, 7)
#define MLX90640_REG_CTL1_MASK_SHIFT    7

struct video_i2c_chip;

struct video_i2c_buffer {
        struct vb2_v4l2_buffer vb;
        struct list_head list;
};

struct video_i2c_data {
        struct regmap *regmap;
        const struct video_i2c_chip *chip;
        struct mutex lock;
        spinlock_t slock;
        unsigned int sequence;
        struct mutex queue_lock;

        struct v4l2_device v4l2_dev;
        struct video_device vdev;
        struct vb2_queue vb_vidq;

        struct task_struct *kthread_vid_cap;
        struct list_head vid_cap_active;

        struct v4l2_fract frame_interval;
};

static const struct v4l2_fmtdesc amg88xx_format = {
        .pixelformat = V4L2_PIX_FMT_Y12,
};

static const struct v4l2_frmsize_discrete amg88xx_size = {
        .width = 8,
        .height = 8,
};

static const struct v4l2_fmtdesc mlx90640_format = {
        .pixelformat = V4L2_PIX_FMT_Y16_BE,
};

static const struct v4l2_frmsize_discrete mlx90640_size = {
        .width = 32,
        .height = 26, /* 24 lines of pixel data + 2 lines of processing data */
};

static const struct regmap_config amg88xx_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0xff
};

static const struct regmap_config mlx90640_regmap_config = {
        .reg_bits = 16,
        .val_bits = 16,
};

struct video_i2c_chip {
        /* video dimensions */
        const struct v4l2_fmtdesc *format;
        const struct v4l2_frmsize_discrete *size;

        /* available frame intervals */
        const struct v4l2_fract *frame_intervals;
        unsigned int num_frame_intervals;

        /* pixel buffer size */
        unsigned int buffer_size;

        /* pixel size in bits */
        unsigned int bpp;

        const struct regmap_config *regmap_config;
        struct nvmem_config *nvmem_config;

        /* setup function */
        int (*setup)(struct video_i2c_data *data);

        /* xfer function */
        int (*xfer)(struct video_i2c_data *data, char *buf);

        /* power control function */
        int (*set_power)(struct video_i2c_data *data, bool on);

        /* hwmon init function */
        int (*hwmon_init)(struct video_i2c_data *data);
};

static int mlx90640_nvram_read(void *priv, unsigned int offset, void *val,
                             size_t bytes)
{
        struct video_i2c_data *data = priv;

        return regmap_bulk_read(data->regmap, MLX90640_EEPROM_START_ADDR + offset, val, bytes);
}

static struct nvmem_config mlx90640_nvram_config = {
        .name = "mlx90640_nvram",
        .word_size = 2,
        .stride = 1,
        .size = 1664,
        .reg_read = mlx90640_nvram_read,
};

static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
{
        return regmap_bulk_read(data->regmap, AMG88XX_REG_T01L, buf,
                                data->chip->buffer_size);
}

static int mlx90640_xfer(struct video_i2c_data *data, char *buf)
{
        return regmap_bulk_read(data->regmap, MLX90640_RAM_START_ADDR, buf,
                                data->chip->buffer_size);
}

static int amg88xx_setup(struct video_i2c_data *data)
{
        unsigned int mask = AMG88XX_FPSC_1FPS;
        unsigned int val;

        if (data->frame_interval.numerator == data->frame_interval.denominator)
                val = mask;
        else
                val = 0;

        return regmap_update_bits(data->regmap, AMG88XX_REG_FPSC, mask, val);
}

static int mlx90640_setup(struct video_i2c_data *data)
{
        unsigned int n, idx;

        for (n = 0; n < data->chip->num_frame_intervals - 1; n++) {
                if (V4L2_FRACT_COMPARE(data->frame_interval, ==,
                                       data->chip->frame_intervals[n]))
                        break;
        }

        idx = data->chip->num_frame_intervals - n - 1;

        return regmap_update_bits(data->regmap, MLX90640_REG_CTL1,
                                  MLX90640_REG_CTL1_MASK,
                                  idx << MLX90640_REG_CTL1_MASK_SHIFT);
}

static int amg88xx_set_power_on(struct video_i2c_data *data)
{
        int ret;

        ret = regmap_write(data->regmap, AMG88XX_REG_PCTL, AMG88XX_PCTL_NORMAL);
        if (ret)
                return ret;

        msleep(50);

        ret = regmap_write(data->regmap, AMG88XX_REG_RST, AMG88XX_RST_INIT);
        if (ret)
                return ret;

        usleep_range(2000, 3000);

        ret = regmap_write(data->regmap, AMG88XX_REG_RST, AMG88XX_RST_FLAG);
        if (ret)
                return ret;

        /*
         * Wait two frames before reading thermistor and temperature registers
         */
        msleep(200);

        return 0;
}

static int amg88xx_set_power_off(struct video_i2c_data *data)
{
        int ret;

        ret = regmap_write(data->regmap, AMG88XX_REG_PCTL, AMG88XX_PCTL_SLEEP);
        if (ret)
                return ret;
        /*
         * Wait for a while to avoid resuming normal mode immediately after
         * entering sleep mode, otherwise the device occasionally goes wrong
         * (thermistor and temperature registers are not updated at all)
         */
        msleep(100);

        return 0;
}

static int amg88xx_set_power(struct video_i2c_data *data, bool on)
{
        if (on)
                return amg88xx_set_power_on(data);

        return amg88xx_set_power_off(data);
}

#if IS_REACHABLE(CONFIG_HWMON)

static const struct hwmon_channel_info * const amg88xx_info[] = {
        HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
        NULL
};

static umode_t amg88xx_is_visible(const void *drvdata,
                                  enum hwmon_sensor_types type,
                                  u32 attr, int channel)
{
        return 0444;
}

static int amg88xx_read(struct device *dev, enum hwmon_sensor_types type,
                        u32 attr, int channel, long *val)
{
        struct video_i2c_data *data = dev_get_drvdata(dev);
        __le16 buf;
        int tmp;

        tmp = pm_runtime_resume_and_get(regmap_get_device(data->regmap));
        if (tmp < 0)
                return tmp;

        tmp = regmap_bulk_read(data->regmap, AMG88XX_REG_TTHL, &buf, 2);
        pm_runtime_put_autosuspend(regmap_get_device(data->regmap));
        if (tmp)
                return tmp;

        tmp = le16_to_cpu(buf);

        /*
         * Check for sign bit, this isn't a two's complement value but an
         * absolute temperature that needs to be inverted in the case of being
         * negative.
         */
        if (tmp & BIT(11))
                tmp = -(tmp & 0x7ff);

        *val = (tmp * 625) / 10;

        return 0;
}

static const struct hwmon_ops amg88xx_hwmon_ops = {
        .is_visible = amg88xx_is_visible,
        .read = amg88xx_read,
};

static const struct hwmon_chip_info amg88xx_chip_info = {
        .ops = &amg88xx_hwmon_ops,
        .info = amg88xx_info,
};

static int amg88xx_hwmon_init(struct video_i2c_data *data)
{
        struct device *dev = regmap_get_device(data->regmap);
        void *hwmon = devm_hwmon_device_register_with_info(dev, "amg88xx", data,
                                                &amg88xx_chip_info, NULL);

        return PTR_ERR_OR_ZERO(hwmon);
}
#else
#define amg88xx_hwmon_init      NULL
#endif

enum {
        AMG88XX,
        MLX90640,
};

static const struct v4l2_fract amg88xx_frame_intervals[] = {
        { 1, 10 },
        { 1, 1 },
};

static const struct v4l2_fract mlx90640_frame_intervals[] = {
        { 1, 64 },
        { 1, 32 },
        { 1, 16 },
        { 1, 8 },
        { 1, 4 },
        { 1, 2 },
        { 1, 1 },
        { 2, 1 },
};

static const struct video_i2c_chip video_i2c_chip[] = {
        [AMG88XX] = {
                .size           = &amg88xx_size,
                .format         = &amg88xx_format,
                .frame_intervals        = amg88xx_frame_intervals,
                .num_frame_intervals    = ARRAY_SIZE(amg88xx_frame_intervals),
                .buffer_size    = 128,
                .bpp            = 16,
                .regmap_config  = &amg88xx_regmap_config,
                .setup          = &amg88xx_setup,
                .xfer           = &amg88xx_xfer,
                .set_power      = amg88xx_set_power,
                .hwmon_init     = amg88xx_hwmon_init,
        },
        [MLX90640] = {
                .size           = &mlx90640_size,
                .format         = &mlx90640_format,
                .frame_intervals        = mlx90640_frame_intervals,
                .num_frame_intervals    = ARRAY_SIZE(mlx90640_frame_intervals),
                .buffer_size    = 1664,
                .bpp            = 16,
                .regmap_config  = &mlx90640_regmap_config,
                .nvmem_config   = &mlx90640_nvram_config,
                .setup          = mlx90640_setup,
                .xfer           = mlx90640_xfer,
        },
};

static const struct v4l2_file_operations video_i2c_fops = {
        .owner          = THIS_MODULE,
        .open           = v4l2_fh_open,
        .release        = vb2_fop_release,
        .poll           = vb2_fop_poll,
        .read           = vb2_fop_read,
        .mmap           = vb2_fop_mmap,
        .unlocked_ioctl = video_ioctl2,
};

static int queue_setup(struct vb2_queue *vq,
                       unsigned int *nbuffers, unsigned int *nplanes,
                       unsigned int sizes[], struct device *alloc_devs[])
{
        struct video_i2c_data *data = vb2_get_drv_priv(vq);
        unsigned int size = data->chip->buffer_size;
        unsigned int q_num_bufs = vb2_get_num_buffers(vq);

        if (q_num_bufs + *nbuffers < 2)
                *nbuffers = 2 - q_num_bufs;

        if (*nplanes)
                return sizes[0] < size ? -EINVAL : 0;

        *nplanes = 1;
        sizes[0] = size;

        return 0;
}

static int buffer_prepare(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct video_i2c_data *data = vb2_get_drv_priv(vb->vb2_queue);
        unsigned int size = data->chip->buffer_size;

        if (vb2_plane_size(vb, 0) < size)
                return -EINVAL;

        vbuf->field = V4L2_FIELD_NONE;
        vb2_set_plane_payload(vb, 0, size);

        return 0;
}

static void buffer_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct video_i2c_data *data = vb2_get_drv_priv(vb->vb2_queue);
        struct video_i2c_buffer *buf =
                        container_of(vbuf, struct video_i2c_buffer, vb);

        spin_lock(&data->slock);
        list_add_tail(&buf->list, &data->vid_cap_active);
        spin_unlock(&data->slock);
}

static int video_i2c_thread_vid_cap(void *priv)
{
        struct video_i2c_data *data = priv;
        u32 delay = mult_frac(1000000UL, data->frame_interval.numerator,
                               data->frame_interval.denominator);
        s64 end_us = ktime_to_us(ktime_get());

        set_freezable();

        do {
                struct video_i2c_buffer *vid_cap_buf = NULL;
                s64 current_us;
                int schedule_delay;

                try_to_freeze();

                spin_lock(&data->slock);

                if (!list_empty(&data->vid_cap_active)) {
                        vid_cap_buf = list_last_entry(&data->vid_cap_active,
                                                 struct video_i2c_buffer, list);
                        list_del(&vid_cap_buf->list);
                }

                spin_unlock(&data->slock);

                if (vid_cap_buf) {
                        struct vb2_buffer *vb2_buf = &vid_cap_buf->vb.vb2_buf;
                        void *vbuf = vb2_plane_vaddr(vb2_buf, 0);
                        int ret;

                        ret = data->chip->xfer(data, vbuf);
                        vb2_buf->timestamp = ktime_get_ns();
                        vid_cap_buf->vb.sequence = data->sequence++;
                        vb2_buffer_done(vb2_buf, ret ?
                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
                }

                end_us += delay;
                current_us = ktime_to_us(ktime_get());
                if (current_us < end_us) {
                        schedule_delay = end_us - current_us;
                        usleep_range(schedule_delay * 3 / 4, schedule_delay);
                } else {
                        end_us = current_us;
                }
        } while (!kthread_should_stop());

        return 0;
}

static void video_i2c_del_list(struct vb2_queue *vq, enum vb2_buffer_state state)
{
        struct video_i2c_data *data = vb2_get_drv_priv(vq);
        struct video_i2c_buffer *buf, *tmp;

        spin_lock(&data->slock);

        list_for_each_entry_safe(buf, tmp, &data->vid_cap_active, list) {
                list_del(&buf->list);
                vb2_buffer_done(&buf->vb.vb2_buf, state);
        }

        spin_unlock(&data->slock);
}

static int start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct video_i2c_data *data = vb2_get_drv_priv(vq);
        struct device *dev = regmap_get_device(data->regmap);
        int ret;

        if (data->kthread_vid_cap)
                return 0;

        ret = pm_runtime_resume_and_get(dev);
        if (ret < 0)
                goto error_del_list;

        ret = data->chip->setup(data);
        if (ret)
                goto error_rpm_put;

        data->sequence = 0;
        data->kthread_vid_cap = kthread_run(video_i2c_thread_vid_cap, data,
                                            "%s-vid-cap", data->v4l2_dev.name);
        ret = PTR_ERR_OR_ZERO(data->kthread_vid_cap);
        if (!ret)
                return 0;

error_rpm_put:
        pm_runtime_put_autosuspend(dev);
error_del_list:
        video_i2c_del_list(vq, VB2_BUF_STATE_QUEUED);

        return ret;
}

static void stop_streaming(struct vb2_queue *vq)
{
        struct video_i2c_data *data = vb2_get_drv_priv(vq);

        if (data->kthread_vid_cap == NULL)
                return;

        kthread_stop(data->kthread_vid_cap);
        data->kthread_vid_cap = NULL;
        pm_runtime_put_autosuspend(regmap_get_device(data->regmap));

        video_i2c_del_list(vq, VB2_BUF_STATE_ERROR);
}

static const struct vb2_ops video_i2c_video_qops = {
        .queue_setup            = queue_setup,
        .buf_prepare            = buffer_prepare,
        .buf_queue              = buffer_queue,
        .start_streaming        = start_streaming,
        .stop_streaming         = stop_streaming,
};

static int video_i2c_querycap(struct file *file, void  *priv,
                                struct v4l2_capability *vcap)
{
        struct video_i2c_data *data = video_drvdata(file);
        struct device *dev = regmap_get_device(data->regmap);
        struct i2c_client *client = to_i2c_client(dev);

        strscpy(vcap->driver, data->v4l2_dev.name, sizeof(vcap->driver));
        strscpy(vcap->card, data->vdev.name, sizeof(vcap->card));

        sprintf(vcap->bus_info, "I2C:%d-%d", client->adapter->nr, client->addr);

        return 0;
}

static int video_i2c_g_input(struct file *file, void *fh, unsigned int *inp)
{
        *inp = 0;

        return 0;
}

static int video_i2c_s_input(struct file *file, void *fh, unsigned int inp)
{
        return (inp > 0) ? -EINVAL : 0;
}

static int video_i2c_enum_input(struct file *file, void *fh,
                                  struct v4l2_input *vin)
{
        if (vin->index > 0)
                return -EINVAL;

        strscpy(vin->name, "Camera", sizeof(vin->name));

        vin->type = V4L2_INPUT_TYPE_CAMERA;

        return 0;
}

static int video_i2c_enum_fmt_vid_cap(struct file *file, void *fh,
                                        struct v4l2_fmtdesc *fmt)
{
        struct video_i2c_data *data = video_drvdata(file);
        enum v4l2_buf_type type = fmt->type;

        if (fmt->index > 0)
                return -EINVAL;

        *fmt = *data->chip->format;
        fmt->type = type;

        return 0;
}

static int video_i2c_enum_framesizes(struct file *file, void *fh,
                                       struct v4l2_frmsizeenum *fsize)
{
        const struct video_i2c_data *data = video_drvdata(file);
        const struct v4l2_frmsize_discrete *size = data->chip->size;

        /* currently only one frame size is allowed */
        if (fsize->index > 0)
                return -EINVAL;

        if (fsize->pixel_format != data->chip->format->pixelformat)
                return -EINVAL;

        fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
        fsize->discrete.width = size->width;
        fsize->discrete.height = size->height;

        return 0;
}

static int video_i2c_enum_frameintervals(struct file *file, void *priv,
                                           struct v4l2_frmivalenum *fe)
{
        const struct video_i2c_data *data = video_drvdata(file);
        const struct v4l2_frmsize_discrete *size = data->chip->size;

        if (fe->index >= data->chip->num_frame_intervals)
                return -EINVAL;

        if (fe->width != size->width || fe->height != size->height)
                return -EINVAL;

        fe->type = V4L2_FRMIVAL_TYPE_DISCRETE;
        fe->discrete = data->chip->frame_intervals[fe->index];

        return 0;
}

static int video_i2c_try_fmt_vid_cap(struct file *file, void *fh,
                                       struct v4l2_format *fmt)
{
        const struct video_i2c_data *data = video_drvdata(file);
        const struct v4l2_frmsize_discrete *size = data->chip->size;
        struct v4l2_pix_format *pix = &fmt->fmt.pix;
        unsigned int bpp = data->chip->bpp / 8;

        pix->width = size->width;
        pix->height = size->height;
        pix->pixelformat = data->chip->format->pixelformat;
        pix->field = V4L2_FIELD_NONE;
        pix->bytesperline = pix->width * bpp;
        pix->sizeimage = pix->bytesperline * pix->height;
        pix->colorspace = V4L2_COLORSPACE_RAW;

        return 0;
}

static int video_i2c_s_fmt_vid_cap(struct file *file, void *fh,
                                     struct v4l2_format *fmt)
{
        struct video_i2c_data *data = video_drvdata(file);

        if (vb2_is_busy(&data->vb_vidq))
                return -EBUSY;

        return video_i2c_try_fmt_vid_cap(file, fh, fmt);
}

static int video_i2c_g_parm(struct file *filp, void *priv,
                              struct v4l2_streamparm *parm)
{
        struct video_i2c_data *data = video_drvdata(filp);

        if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        parm->parm.capture.readbuffers = 1;
        parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
        parm->parm.capture.timeperframe = data->frame_interval;

        return 0;
}

static int video_i2c_s_parm(struct file *filp, void *priv,
                              struct v4l2_streamparm *parm)
{
        struct video_i2c_data *data = video_drvdata(filp);
        int i;

        for (i = 0; i < data->chip->num_frame_intervals - 1; i++) {
                if (V4L2_FRACT_COMPARE(parm->parm.capture.timeperframe, <=,
                                       data->chip->frame_intervals[i]))
                        break;
        }
        data->frame_interval = data->chip->frame_intervals[i];

        return video_i2c_g_parm(filp, priv, parm);
}

static const struct v4l2_ioctl_ops video_i2c_ioctl_ops = {
        .vidioc_querycap                = video_i2c_querycap,
        .vidioc_g_input                 = video_i2c_g_input,
        .vidioc_s_input                 = video_i2c_s_input,
        .vidioc_enum_input              = video_i2c_enum_input,
        .vidioc_enum_fmt_vid_cap        = video_i2c_enum_fmt_vid_cap,
        .vidioc_enum_framesizes         = video_i2c_enum_framesizes,
        .vidioc_enum_frameintervals     = video_i2c_enum_frameintervals,
        .vidioc_g_fmt_vid_cap           = video_i2c_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap           = video_i2c_s_fmt_vid_cap,
        .vidioc_g_parm                  = video_i2c_g_parm,
        .vidioc_s_parm                  = video_i2c_s_parm,
        .vidioc_try_fmt_vid_cap         = video_i2c_try_fmt_vid_cap,
        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,
};

static void video_i2c_release(struct video_device *vdev)
{
        struct video_i2c_data *data = video_get_drvdata(vdev);

        v4l2_device_unregister(&data->v4l2_dev);
        mutex_destroy(&data->lock);
        mutex_destroy(&data->queue_lock);
        regmap_exit(data->regmap);
        kfree(data);
}

static int video_i2c_probe(struct i2c_client *client)
{
        struct video_i2c_data *data;
        struct v4l2_device *v4l2_dev;
        struct vb2_queue *queue;
        int ret = -ENODEV;

        data = kzalloc_obj(*data);
        if (!data)
                return -ENOMEM;

        data->chip = i2c_get_match_data(client);
        if (!data->chip)
                goto error_free_device;

        data->regmap = regmap_init_i2c(client, data->chip->regmap_config);
        if (IS_ERR(data->regmap)) {
                ret = PTR_ERR(data->regmap);
                goto error_free_device;
        }

        v4l2_dev = &data->v4l2_dev;
        strscpy(v4l2_dev->name, VIDEO_I2C_DRIVER, sizeof(v4l2_dev->name));

        ret = v4l2_device_register(&client->dev, v4l2_dev);
        if (ret < 0)
                goto error_regmap_exit;

        mutex_init(&data->lock);
        mutex_init(&data->queue_lock);

        queue = &data->vb_vidq;
        queue->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        queue->io_modes = VB2_DMABUF | VB2_MMAP | VB2_USERPTR | VB2_READ;
        queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        queue->drv_priv = data;
        queue->buf_struct_size = sizeof(struct video_i2c_buffer);
        queue->min_queued_buffers = 1;
        queue->ops = &video_i2c_video_qops;
        queue->mem_ops = &vb2_vmalloc_memops;
        queue->lock = &data->queue_lock;

        ret = vb2_queue_init(queue);
        if (ret < 0)
                goto error_unregister_device;

        data->vdev.queue = queue;

        snprintf(data->vdev.name, sizeof(data->vdev.name),
                                 "I2C %d-%d Transport Video",
                                 client->adapter->nr, client->addr);

        data->vdev.v4l2_dev = v4l2_dev;
        data->vdev.fops = &video_i2c_fops;
        data->vdev.lock = &data->lock;
        data->vdev.ioctl_ops = &video_i2c_ioctl_ops;
        data->vdev.release = video_i2c_release;
        data->vdev.device_caps = V4L2_CAP_VIDEO_CAPTURE |
                                 V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;

        spin_lock_init(&data->slock);
        INIT_LIST_HEAD(&data->vid_cap_active);

        data->frame_interval = data->chip->frame_intervals[0];

        video_set_drvdata(&data->vdev, data);
        i2c_set_clientdata(client, data);

        if (data->chip->set_power) {
                ret = data->chip->set_power(data, true);
                if (ret)
                        goto error_unregister_device;
        }

        pm_runtime_get_noresume(&client->dev);
        pm_runtime_set_active(&client->dev);
        pm_runtime_enable(&client->dev);
        pm_runtime_set_autosuspend_delay(&client->dev, 2000);
        pm_runtime_use_autosuspend(&client->dev);

        if (data->chip->hwmon_init) {
                ret = data->chip->hwmon_init(data);
                if (ret < 0) {
                        dev_warn(&client->dev,
                                 "failed to register hwmon device\n");
                }
        }

        if (data->chip->nvmem_config) {
                struct nvmem_config *config = data->chip->nvmem_config;
                struct nvmem_device *device;

                config->priv = data;
                config->dev = &client->dev;

                device = devm_nvmem_register(&client->dev, config);

                if (IS_ERR(device)) {
                        dev_warn(&client->dev,
                                 "failed to register nvmem device\n");
                }
        }

        ret = video_register_device(&data->vdev, VFL_TYPE_VIDEO, -1);
        if (ret < 0)
                goto error_pm_disable;

        pm_runtime_put_autosuspend(&client->dev);

        return 0;

error_pm_disable:
        pm_runtime_disable(&client->dev);
        pm_runtime_set_suspended(&client->dev);
        pm_runtime_put_noidle(&client->dev);

        if (data->chip->set_power)
                data->chip->set_power(data, false);

error_unregister_device:
        v4l2_device_unregister(v4l2_dev);
        mutex_destroy(&data->lock);
        mutex_destroy(&data->queue_lock);

error_regmap_exit:
        regmap_exit(data->regmap);

error_free_device:
        kfree(data);

        return ret;
}

static void video_i2c_remove(struct i2c_client *client)
{
        struct video_i2c_data *data = i2c_get_clientdata(client);

        pm_runtime_get_sync(&client->dev);
        pm_runtime_disable(&client->dev);
        pm_runtime_set_suspended(&client->dev);
        pm_runtime_put_noidle(&client->dev);

        if (data->chip->set_power)
                data->chip->set_power(data, false);

        video_unregister_device(&data->vdev);
}

#ifdef CONFIG_PM

static int video_i2c_pm_runtime_suspend(struct device *dev)
{
        struct video_i2c_data *data = i2c_get_clientdata(to_i2c_client(dev));

        if (!data->chip->set_power)
                return 0;

        return data->chip->set_power(data, false);
}

static int video_i2c_pm_runtime_resume(struct device *dev)
{
        struct video_i2c_data *data = i2c_get_clientdata(to_i2c_client(dev));

        if (!data->chip->set_power)
                return 0;

        return data->chip->set_power(data, true);
}

#endif

static const struct dev_pm_ops video_i2c_pm_ops = {
        SET_RUNTIME_PM_OPS(video_i2c_pm_runtime_suspend,
                           video_i2c_pm_runtime_resume, NULL)
};

static const struct i2c_device_id video_i2c_id_table[] = {
        { "amg88xx", (kernel_ulong_t)&video_i2c_chip[AMG88XX] },
        { "mlx90640", (kernel_ulong_t)&video_i2c_chip[MLX90640] },
        {}
};
MODULE_DEVICE_TABLE(i2c, video_i2c_id_table);

static const struct of_device_id video_i2c_of_match[] = {
        { .compatible = "panasonic,amg88xx", .data = &video_i2c_chip[AMG88XX] },
        { .compatible = "melexis,mlx90640", .data = &video_i2c_chip[MLX90640] },
        {}
};
MODULE_DEVICE_TABLE(of, video_i2c_of_match);

static struct i2c_driver video_i2c_driver = {
        .driver = {
                .name   = VIDEO_I2C_DRIVER,
                .of_match_table = video_i2c_of_match,
                .pm     = &video_i2c_pm_ops,
        },
        .probe          = video_i2c_probe,
        .remove         = video_i2c_remove,
        .id_table       = video_i2c_id_table,
};

module_i2c_driver(video_i2c_driver);

MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("I2C transport video support");
MODULE_LICENSE("GPL v2");