// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2015 Synaptics Incorporated
 * Copyright (C) 2016 Zodiac Inflight Innovations
 */

#include <linux/kernel.h>
#include <linux/rmi.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-vmalloc.h>
#include "rmi_driver.h"

#define F54_NAME                "rmi4_f54"

/* F54 data offsets */
#define F54_REPORT_DATA_OFFSET  3
#define F54_FIFO_OFFSET         1
#define F54_NUM_TX_OFFSET       1
#define F54_NUM_RX_OFFSET       0

/*
 * The smbus protocol can read only 32 bytes max at a time.
 * But this should be fine for i2c/spi as well.
 */
#define F54_REPORT_DATA_SIZE    32

/* F54 commands */
#define F54_GET_REPORT          1
#define F54_FORCE_CAL           2

/* F54 capabilities */
#define F54_CAP_BASELINE        (1 << 2)
#define F54_CAP_IMAGE8          (1 << 3)
#define F54_CAP_IMAGE16         (1 << 6)

/**
 * enum rmi_f54_report_type - RMI4 F54 report types
 *
 * @F54_REPORT_NONE:    No Image Report.
 *
 * @F54_8BIT_IMAGE:     Normalized 8-Bit Image Report. The capacitance variance
 *                      from baseline for each pixel.
 *
 * @F54_16BIT_IMAGE:    Normalized 16-Bit Image Report. The capacitance variance
 *                      from baseline for each pixel.
 *
 * @F54_RAW_16BIT_IMAGE:
 *                      Raw 16-Bit Image Report. The raw capacitance for each
 *                      pixel.
 *
 * @F54_TRUE_BASELINE:  True Baseline Report. The baseline capacitance for each
 *                      pixel.
 *
 * @F54_FULL_RAW_CAP:   Full Raw Capacitance Report. The raw capacitance with
 *                      low reference set to its minimum value and high
 *                      reference set to its maximum value.
 *
 * @F54_FULL_RAW_CAP_RX_OFFSET_REMOVED:
 *                      Full Raw Capacitance with Receiver Offset Removed
 *                      Report. Set Low reference to its minimum value and high
 *                      references to its maximum value, then report the raw
 *                      capacitance for each pixel.
 *
 * @F54_MAX_REPORT_TYPE:
 *                      Maximum number of Report Types.  Used for sanity
 *                      checking.
 */
enum rmi_f54_report_type {
        F54_REPORT_NONE = 0,
        F54_8BIT_IMAGE = 1,
        F54_16BIT_IMAGE = 2,
        F54_RAW_16BIT_IMAGE = 3,
        F54_TRUE_BASELINE = 9,
        F54_FULL_RAW_CAP = 19,
        F54_FULL_RAW_CAP_RX_OFFSET_REMOVED = 20,
        F54_MAX_REPORT_TYPE,
};

static const char * const rmi_f54_report_type_names[] = {
        [F54_REPORT_NONE]               = "Unknown",
        [F54_8BIT_IMAGE]                = "Normalized 8-Bit Image",
        [F54_16BIT_IMAGE]               = "Normalized 16-Bit Image",
        [F54_RAW_16BIT_IMAGE]           = "Raw 16-Bit Image",
        [F54_TRUE_BASELINE]             = "True Baseline",
        [F54_FULL_RAW_CAP]              = "Full Raw Capacitance",
        [F54_FULL_RAW_CAP_RX_OFFSET_REMOVED]
                                        = "Full Raw Capacitance RX Offset Removed",
};

struct f54_data {
        struct rmi_function *fn;

        u8 num_rx_electrodes;
        u8 num_tx_electrodes;
        u8 capabilities;
        u16 clock_rate;
        u8 family;

        enum rmi_f54_report_type report_type;
        u8 *report_data;
        int report_size;

        bool is_busy;
        struct mutex status_mutex;
        struct mutex data_mutex;

        struct workqueue_struct *workqueue;
        struct delayed_work work;
        unsigned long timeout;

        struct completion cmd_done;

        /* V4L2 support */
        struct v4l2_device v4l2;
        struct v4l2_pix_format format;
        struct video_device vdev;
        struct vb2_queue queue;
        struct mutex lock;
        u32 sequence;
        int input;
        enum rmi_f54_report_type inputs[F54_MAX_REPORT_TYPE];
};

/*
 * Basic checks on report_type to ensure we write a valid type
 * to the sensor.
 */
static bool is_f54_report_type_valid(struct f54_data *f54,
                                     enum rmi_f54_report_type reptype)
{
        switch (reptype) {
        case F54_8BIT_IMAGE:
                return f54->capabilities & F54_CAP_IMAGE8;
        case F54_16BIT_IMAGE:
        case F54_RAW_16BIT_IMAGE:
                return f54->capabilities & F54_CAP_IMAGE16;
        case F54_TRUE_BASELINE:
                return f54->capabilities & F54_CAP_IMAGE16;
        case F54_FULL_RAW_CAP:
        case F54_FULL_RAW_CAP_RX_OFFSET_REMOVED:
                return true;
        default:
                return false;
        }
}

static enum rmi_f54_report_type rmi_f54_get_reptype(struct f54_data *f54,
                                                unsigned int i)
{
        if (i >= F54_MAX_REPORT_TYPE)
                return F54_REPORT_NONE;

        return f54->inputs[i];
}

static void rmi_f54_create_input_map(struct f54_data *f54)
{
        int i = 0;
        enum rmi_f54_report_type reptype;

        for (reptype = 1; reptype < F54_MAX_REPORT_TYPE; reptype++) {
                if (!is_f54_report_type_valid(f54, reptype))
                        continue;

                f54->inputs[i++] = reptype;
        }

        /* Remaining values are zero via kzalloc */
}

static int rmi_f54_request_report(struct rmi_function *fn, u8 report_type)
{
        struct f54_data *f54 = dev_get_drvdata(&fn->dev);
        struct rmi_device *rmi_dev = fn->rmi_dev;
        int error;

        /* Write Report Type into F54_AD_Data0 */
        if (f54->report_type != report_type) {
                error = rmi_write(rmi_dev, f54->fn->fd.data_base_addr,
                                  report_type);
                if (error)
                        return error;
                f54->report_type = report_type;
        }

        /*
         * Small delay after disabling interrupts to avoid race condition
         * in firmare. This value is a bit higher than absolutely necessary.
         * Should be removed once issue is resolved in firmware.
         */
        usleep_range(2000, 3000);

        mutex_lock(&f54->data_mutex);

        error = rmi_write(rmi_dev, fn->fd.command_base_addr, F54_GET_REPORT);
        if (error < 0)
                goto unlock;

        init_completion(&f54->cmd_done);

        f54->is_busy = 1;
        f54->timeout = jiffies + msecs_to_jiffies(100);

        queue_delayed_work(f54->workqueue, &f54->work, 0);

unlock:
        mutex_unlock(&f54->data_mutex);

        return error;
}

static size_t rmi_f54_get_report_size(struct f54_data *f54)
{
        struct rmi_device *rmi_dev = f54->fn->rmi_dev;
        struct rmi_driver_data *drv_data = dev_get_drvdata(&rmi_dev->dev);
        u8 rx = drv_data->num_rx_electrodes ? : f54->num_rx_electrodes;
        u8 tx = drv_data->num_tx_electrodes ? : f54->num_tx_electrodes;
        size_t size;

        switch (rmi_f54_get_reptype(f54, f54->input)) {
        case F54_8BIT_IMAGE:
                size = rx * tx;
                break;
        case F54_16BIT_IMAGE:
        case F54_RAW_16BIT_IMAGE:
        case F54_TRUE_BASELINE:
        case F54_FULL_RAW_CAP:
        case F54_FULL_RAW_CAP_RX_OFFSET_REMOVED:
                size = sizeof(u16) * rx * tx;
                break;
        default:
                size = 0;
        }

        return size;
}

static int rmi_f54_get_pixel_fmt(enum rmi_f54_report_type reptype, u32 *pixfmt)
{
        int ret = 0;

        switch (reptype) {
        case F54_8BIT_IMAGE:
                *pixfmt = V4L2_TCH_FMT_DELTA_TD08;
                break;

        case F54_16BIT_IMAGE:
                *pixfmt = V4L2_TCH_FMT_DELTA_TD16;
                break;

        case F54_RAW_16BIT_IMAGE:
        case F54_TRUE_BASELINE:
        case F54_FULL_RAW_CAP:
        case F54_FULL_RAW_CAP_RX_OFFSET_REMOVED:
                *pixfmt = V4L2_TCH_FMT_TU16;
                break;

        case F54_REPORT_NONE:
        case F54_MAX_REPORT_TYPE:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static const struct v4l2_file_operations rmi_f54_video_fops = {
        .owner = THIS_MODULE,
        .open = v4l2_fh_open,
        .release = vb2_fop_release,
        .unlocked_ioctl = video_ioctl2,
        .read = vb2_fop_read,
        .mmap = vb2_fop_mmap,
        .poll = vb2_fop_poll,
};

static int rmi_f54_queue_setup(struct vb2_queue *q, unsigned int *nbuffers,
                               unsigned int *nplanes, unsigned int sizes[],
                               struct device *alloc_devs[])
{
        struct f54_data *f54 = q->drv_priv;

        if (*nplanes)
                return sizes[0] < rmi_f54_get_report_size(f54) ? -EINVAL : 0;

        *nplanes = 1;
        sizes[0] = rmi_f54_get_report_size(f54);

        return 0;
}

static void rmi_f54_buffer_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct f54_data *f54 = vb2_get_drv_priv(vb->vb2_queue);
        u16 *ptr;
        enum vb2_buffer_state state;
        enum rmi_f54_report_type reptype;
        int ret;

        mutex_lock(&f54->status_mutex);

        vb2_set_plane_payload(vb, 0, 0);
        reptype = rmi_f54_get_reptype(f54, f54->input);
        if (reptype == F54_REPORT_NONE) {
                state = VB2_BUF_STATE_ERROR;
                goto done;
        }

        if (f54->is_busy) {
                state = VB2_BUF_STATE_ERROR;
                goto done;
        }

        ret = rmi_f54_request_report(f54->fn, reptype);
        if (ret) {
                dev_err(&f54->fn->dev, "Error requesting F54 report\n");
                state = VB2_BUF_STATE_ERROR;
                goto done;
        }

        /* get frame data */
        mutex_lock(&f54->data_mutex);

        while (f54->is_busy) {
                mutex_unlock(&f54->data_mutex);
                if (!wait_for_completion_timeout(&f54->cmd_done,
                                                 msecs_to_jiffies(1000))) {
                        dev_err(&f54->fn->dev, "Timed out\n");
                        state = VB2_BUF_STATE_ERROR;
                        goto done;
                }
                mutex_lock(&f54->data_mutex);
        }

        ptr = vb2_plane_vaddr(vb, 0);
        if (!ptr) {
                dev_err(&f54->fn->dev, "Error acquiring frame ptr\n");
                state = VB2_BUF_STATE_ERROR;
                goto data_done;
        }

        memcpy(ptr, f54->report_data, f54->report_size);
        vb2_set_plane_payload(vb, 0, rmi_f54_get_report_size(f54));
        state = VB2_BUF_STATE_DONE;

data_done:
        mutex_unlock(&f54->data_mutex);
done:
        vb->timestamp = ktime_get_ns();
        vbuf->field = V4L2_FIELD_NONE;
        vbuf->sequence = f54->sequence++;
        vb2_buffer_done(vb, state);
        mutex_unlock(&f54->status_mutex);
}

static void rmi_f54_stop_streaming(struct vb2_queue *q)
{
        struct f54_data *f54 = vb2_get_drv_priv(q);

        f54->sequence = 0;
}

/* V4L2 structures */
static const struct vb2_ops rmi_f54_queue_ops = {
        .queue_setup            = rmi_f54_queue_setup,
        .buf_queue              = rmi_f54_buffer_queue,
        .stop_streaming         = rmi_f54_stop_streaming,
        .wait_prepare           = vb2_ops_wait_prepare,
        .wait_finish            = vb2_ops_wait_finish,
};

static const struct vb2_queue rmi_f54_queue = {
        .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
        .io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF | VB2_READ,
        .buf_struct_size = sizeof(struct vb2_v4l2_buffer),
        .ops = &rmi_f54_queue_ops,
        .mem_ops = &vb2_vmalloc_memops,
        .timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
};

static int rmi_f54_vidioc_querycap(struct file *file, void *priv,
                                   struct v4l2_capability *cap)
{
        struct f54_data *f54 = video_drvdata(file);

        strlcpy(cap->driver, F54_NAME, sizeof(cap->driver));
        strlcpy(cap->card, SYNAPTICS_INPUT_DEVICE_NAME, sizeof(cap->card));
        snprintf(cap->bus_info, sizeof(cap->bus_info),
                "rmi4:%s", dev_name(&f54->fn->dev));

        return 0;
}

static int rmi_f54_vidioc_enum_input(struct file *file, void *priv,
                                     struct v4l2_input *i)
{
        struct f54_data *f54 = video_drvdata(file);
        enum rmi_f54_report_type reptype;

        reptype = rmi_f54_get_reptype(f54, i->index);
        if (reptype == F54_REPORT_NONE)
                return -EINVAL;

        i->type = V4L2_INPUT_TYPE_TOUCH;

        strlcpy(i->name, rmi_f54_report_type_names[reptype], sizeof(i->name));
        return 0;
}

static int rmi_f54_set_input(struct f54_data *f54, unsigned int i)
{
        struct rmi_device *rmi_dev = f54->fn->rmi_dev;
        struct rmi_driver_data *drv_data = dev_get_drvdata(&rmi_dev->dev);
        u8 rx = drv_data->num_rx_electrodes ? : f54->num_rx_electrodes;
        u8 tx = drv_data->num_tx_electrodes ? : f54->num_tx_electrodes;
        struct v4l2_pix_format *f = &f54->format;
        enum rmi_f54_report_type reptype;
        int ret;

        reptype = rmi_f54_get_reptype(f54, i);
        if (reptype == F54_REPORT_NONE)
                return -EINVAL;

        ret = rmi_f54_get_pixel_fmt(reptype, &f->pixelformat);
        if (ret)
                return ret;

        f54->input = i;

        f->width = rx;
        f->height = tx;
        f->field = V4L2_FIELD_NONE;
        f->colorspace = V4L2_COLORSPACE_RAW;
        f->bytesperline = f->width * sizeof(u16);
        f->sizeimage = f->width * f->height * sizeof(u16);

        return 0;
}

static int rmi_f54_vidioc_s_input(struct file *file, void *priv, unsigned int i)
{
        return rmi_f54_set_input(video_drvdata(file), i);
}

static int rmi_f54_vidioc_g_input(struct file *file, void *priv,
                                  unsigned int *i)
{
        struct f54_data *f54 = video_drvdata(file);

        *i = f54->input;

        return 0;
}

static int rmi_f54_vidioc_fmt(struct file *file, void *priv,
                              struct v4l2_format *f)
{
        struct f54_data *f54 = video_drvdata(file);

        f->fmt.pix = f54->format;

        return 0;
}

static int rmi_f54_vidioc_enum_fmt(struct file *file, void *priv,
                                   struct v4l2_fmtdesc *fmt)
{
        struct f54_data *f54 = video_drvdata(file);

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

        if (fmt->index)
                return -EINVAL;

        fmt->pixelformat = f54->format.pixelformat;

        return 0;
}

static int rmi_f54_vidioc_g_parm(struct file *file, void *fh,
                                 struct v4l2_streamparm *a)
{
        if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        a->parm.capture.readbuffers = 1;
        a->parm.capture.timeperframe.numerator = 1;
        a->parm.capture.timeperframe.denominator = 10;
        return 0;
}

static const struct v4l2_ioctl_ops rmi_f54_video_ioctl_ops = {
        .vidioc_querycap        = rmi_f54_vidioc_querycap,

        .vidioc_enum_fmt_vid_cap = rmi_f54_vidioc_enum_fmt,
        .vidioc_s_fmt_vid_cap   = rmi_f54_vidioc_fmt,
        .vidioc_g_fmt_vid_cap   = rmi_f54_vidioc_fmt,
        .vidioc_try_fmt_vid_cap = rmi_f54_vidioc_fmt,
        .vidioc_g_parm          = rmi_f54_vidioc_g_parm,

        .vidioc_enum_input      = rmi_f54_vidioc_enum_input,
        .vidioc_g_input         = rmi_f54_vidioc_g_input,
        .vidioc_s_input         = rmi_f54_vidioc_s_input,

        .vidioc_reqbufs         = vb2_ioctl_reqbufs,
        .vidioc_create_bufs     = vb2_ioctl_create_bufs,
        .vidioc_querybuf        = vb2_ioctl_querybuf,
        .vidioc_qbuf            = vb2_ioctl_qbuf,
        .vidioc_dqbuf           = vb2_ioctl_dqbuf,
        .vidioc_expbuf          = vb2_ioctl_expbuf,

        .vidioc_streamon        = vb2_ioctl_streamon,
        .vidioc_streamoff       = vb2_ioctl_streamoff,
};

static const struct video_device rmi_f54_video_device = {
        .name = "Synaptics RMI4",
        .fops = &rmi_f54_video_fops,
        .ioctl_ops = &rmi_f54_video_ioctl_ops,
        .release = video_device_release_empty,
        .device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_TOUCH |
                       V4L2_CAP_READWRITE | V4L2_CAP_STREAMING,
};

static void rmi_f54_work(struct work_struct *work)
{
        struct f54_data *f54 = container_of(work, struct f54_data, work.work);
        struct rmi_function *fn = f54->fn;
        u8 fifo[2];
        int report_size;
        u8 command;
        int error;
        int i;

        report_size = rmi_f54_get_report_size(f54);
        if (report_size == 0) {
                dev_err(&fn->dev, "Bad report size, report type=%d\n",
                                f54->report_type);
                error = -EINVAL;
                goto error;     /* retry won't help */
        }

        mutex_lock(&f54->data_mutex);

        /*
         * Need to check if command has completed.
         * If not try again later.
         */
        error = rmi_read(fn->rmi_dev, f54->fn->fd.command_base_addr,
                         &command);
        if (error) {
                dev_err(&fn->dev, "Failed to read back command\n");
                goto error;
        }
        if (command & F54_GET_REPORT) {
                if (time_after(jiffies, f54->timeout)) {
                        dev_err(&fn->dev, "Get report command timed out\n");
                        error = -ETIMEDOUT;
                }
                report_size = 0;
                goto error;
        }

        rmi_dbg(RMI_DEBUG_FN, &fn->dev, "Get report command completed, reading data\n");

        for (i = 0; i < report_size; i += F54_REPORT_DATA_SIZE) {
                int size = min(F54_REPORT_DATA_SIZE, report_size - i);

                fifo[0] = i & 0xff;
                fifo[1] = i >> 8;
                error = rmi_write_block(fn->rmi_dev,
                                        fn->fd.data_base_addr + F54_FIFO_OFFSET,
                                        fifo, sizeof(fifo));
                if (error) {
                        dev_err(&fn->dev, "Failed to set fifo start offset\n");
                        goto abort;
                }

                error = rmi_read_block(fn->rmi_dev, fn->fd.data_base_addr +
                                       F54_REPORT_DATA_OFFSET,
                                       f54->report_data + i, size);
                if (error) {
                        dev_err(&fn->dev, "%s: read [%d bytes] returned %d\n",
                                __func__, size, error);
                        goto abort;
                }
        }

abort:
        f54->report_size = error ? 0 : report_size;
error:
        if (error)
                report_size = 0;

        if (report_size == 0 && !error) {
                queue_delayed_work(f54->workqueue, &f54->work,
                                   msecs_to_jiffies(1));
        } else {
                f54->is_busy = false;
                complete(&f54->cmd_done);
        }

        mutex_unlock(&f54->data_mutex);
}

static int rmi_f54_config(struct rmi_function *fn)
{
        struct rmi_driver *drv = fn->rmi_dev->driver;

        drv->clear_irq_bits(fn->rmi_dev, fn->irq_mask);

        return 0;
}

static int rmi_f54_detect(struct rmi_function *fn)
{
        int error;
        struct f54_data *f54;
        u8 buf[6];

        f54 = dev_get_drvdata(&fn->dev);

        error = rmi_read_block(fn->rmi_dev, fn->fd.query_base_addr,
                               buf, sizeof(buf));
        if (error) {
                dev_err(&fn->dev, "%s: Failed to query F54 properties\n",
                        __func__);
                return error;
        }

        f54->num_rx_electrodes = buf[0];
        f54->num_tx_electrodes = buf[1];
        f54->capabilities = buf[2];
        f54->clock_rate = buf[3] | (buf[4] << 8);
        f54->family = buf[5];

        rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F54 num_rx_electrodes: %d\n",
                f54->num_rx_electrodes);
        rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F54 num_tx_electrodes: %d\n",
                f54->num_tx_electrodes);
        rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F54 capabilities: 0x%x\n",
                f54->capabilities);
        rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F54 clock rate: 0x%x\n",
                f54->clock_rate);
        rmi_dbg(RMI_DEBUG_FN, &fn->dev, "F54 family: 0x%x\n",
                f54->family);

        f54->is_busy = false;

        return 0;
}

static int rmi_f54_probe(struct rmi_function *fn)
{
        struct f54_data *f54;
        int ret;
        u8 rx, tx;

        f54 = devm_kzalloc(&fn->dev, sizeof(struct f54_data), GFP_KERNEL);
        if (!f54)
                return -ENOMEM;

        f54->fn = fn;
        dev_set_drvdata(&fn->dev, f54);

        ret = rmi_f54_detect(fn);
        if (ret)
                return ret;

        mutex_init(&f54->data_mutex);
        mutex_init(&f54->status_mutex);

        rx = f54->num_rx_electrodes;
        tx = f54->num_tx_electrodes;
        f54->report_data = devm_kzalloc(&fn->dev,
                                        array3_size(tx, rx, sizeof(u16)),
                                        GFP_KERNEL);
        if (f54->report_data == NULL)
                return -ENOMEM;

        INIT_DELAYED_WORK(&f54->work, rmi_f54_work);

        f54->workqueue = create_singlethread_workqueue("rmi4-poller");
        if (!f54->workqueue)
                return -ENOMEM;

        rmi_f54_create_input_map(f54);
        rmi_f54_set_input(f54, 0);

        /* register video device */
        strlcpy(f54->v4l2.name, F54_NAME, sizeof(f54->v4l2.name));
        ret = v4l2_device_register(&fn->dev, &f54->v4l2);
        if (ret) {
                dev_err(&fn->dev, "Unable to register video dev.\n");
                goto remove_wq;
        }

        /* initialize the queue */
        mutex_init(&f54->lock);
        f54->queue = rmi_f54_queue;
        f54->queue.drv_priv = f54;
        f54->queue.lock = &f54->lock;
        f54->queue.dev = &fn->dev;

        ret = vb2_queue_init(&f54->queue);
        if (ret)
                goto remove_v4l2;

        f54->vdev = rmi_f54_video_device;
        f54->vdev.v4l2_dev = &f54->v4l2;
        f54->vdev.lock = &f54->lock;
        f54->vdev.vfl_dir = VFL_DIR_RX;
        f54->vdev.queue = &f54->queue;
        video_set_drvdata(&f54->vdev, f54);

        ret = video_register_device(&f54->vdev, VFL_TYPE_TOUCH, -1);
        if (ret) {
                dev_err(&fn->dev, "Unable to register video subdevice.");
                goto remove_v4l2;
        }

        return 0;

remove_v4l2:
        v4l2_device_unregister(&f54->v4l2);
remove_wq:
        cancel_delayed_work_sync(&f54->work);
        flush_workqueue(f54->workqueue);
        destroy_workqueue(f54->workqueue);
        return ret;
}

static void rmi_f54_remove(struct rmi_function *fn)
{
        struct f54_data *f54 = dev_get_drvdata(&fn->dev);

        video_unregister_device(&f54->vdev);
        v4l2_device_unregister(&f54->v4l2);
        destroy_workqueue(f54->workqueue);
}

struct rmi_function_handler rmi_f54_handler = {
        .driver = {
                .name = F54_NAME,
        },
        .func = 0x54,
        .probe = rmi_f54_probe,
        .config = rmi_f54_config,
        .remove = rmi_f54_remove,
};