// SPDX-License-Identifier: GPL-2.0
/*
 * Allwinner sun8i DE2 rotation driver
 *
 * Copyright (C) 2020 Jernej Skrabec <jernej.skrabec@siol.net>
 */

#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>

#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mem2mem.h>

#include "sun8i-formats.h"
#include "sun8i-rotate.h"

static inline u32 rotate_read(struct rotate_dev *dev, u32 reg)
{
        return readl(dev->base + reg);
}

static inline void rotate_write(struct rotate_dev *dev, u32 reg, u32 value)
{
        writel(value, dev->base + reg);
}

static inline void rotate_set_bits(struct rotate_dev *dev, u32 reg, u32 bits)
{
        writel(readl(dev->base + reg) | bits, dev->base + reg);
}

static void rotate_calc_addr_pitch(dma_addr_t buffer,
                                   u32 bytesperline, u32 height,
                                   const struct rotate_format *fmt,
                                   dma_addr_t *addr, u32 *pitch)
{
        u32 size;
        int i;

        for (i = 0; i < fmt->planes; i++) {
                pitch[i] = bytesperline;
                addr[i] = buffer;
                if (i > 0)
                        pitch[i] /= fmt->hsub / fmt->bpp[i];
                size = pitch[i] * height;
                if (i > 0)
                        size /= fmt->vsub;
                buffer += size;
        }
}

static void rotate_device_run(void *priv)
{
        struct rotate_ctx *ctx = priv;
        struct rotate_dev *dev = ctx->dev;
        struct vb2_v4l2_buffer *src, *dst;
        const struct rotate_format *fmt;
        dma_addr_t addr[3];
        u32 val, pitch[3];

        src = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
        dst = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);

        v4l2_m2m_buf_copy_metadata(src, dst);

        val = ROTATE_GLB_CTL_MODE(ROTATE_MODE_COPY_ROTATE);
        if (ctx->hflip)
                val |= ROTATE_GLB_CTL_HFLIP;
        if (ctx->vflip)
                val |= ROTATE_GLB_CTL_VFLIP;
        val |= ROTATE_GLB_CTL_ROTATION(ctx->rotate / 90);
        if (ctx->rotate != 90 && ctx->rotate != 270)
                val |= ROTATE_GLB_CTL_BURST_LEN(ROTATE_BURST_64);
        else
                val |= ROTATE_GLB_CTL_BURST_LEN(ROTATE_BURST_8);
        rotate_write(dev, ROTATE_GLB_CTL, val);

        fmt = rotate_find_format(ctx->src_fmt.pixelformat);
        if (!fmt)
                return;

        rotate_write(dev, ROTATE_IN_FMT, ROTATE_IN_FMT_FORMAT(fmt->hw_format));

        rotate_calc_addr_pitch(vb2_dma_contig_plane_dma_addr(&src->vb2_buf, 0),
                               ctx->src_fmt.bytesperline, ctx->src_fmt.height,
                               fmt, addr, pitch);

        rotate_write(dev, ROTATE_IN_SIZE,
                     ROTATE_SIZE(ctx->src_fmt.width, ctx->src_fmt.height));

        rotate_write(dev, ROTATE_IN_PITCH0, pitch[0]);
        rotate_write(dev, ROTATE_IN_PITCH1, pitch[1]);
        rotate_write(dev, ROTATE_IN_PITCH2, pitch[2]);

        rotate_write(dev, ROTATE_IN_ADDRL0, addr[0]);
        rotate_write(dev, ROTATE_IN_ADDRL1, addr[1]);
        rotate_write(dev, ROTATE_IN_ADDRL2, addr[2]);

        rotate_write(dev, ROTATE_IN_ADDRH0, 0);
        rotate_write(dev, ROTATE_IN_ADDRH1, 0);
        rotate_write(dev, ROTATE_IN_ADDRH2, 0);

        fmt = rotate_find_format(ctx->dst_fmt.pixelformat);
        if (!fmt)
                return;

        rotate_calc_addr_pitch(vb2_dma_contig_plane_dma_addr(&dst->vb2_buf, 0),
                               ctx->dst_fmt.bytesperline, ctx->dst_fmt.height,
                               fmt, addr, pitch);

        rotate_write(dev, ROTATE_OUT_SIZE,
                     ROTATE_SIZE(ctx->dst_fmt.width, ctx->dst_fmt.height));

        rotate_write(dev, ROTATE_OUT_PITCH0, pitch[0]);
        rotate_write(dev, ROTATE_OUT_PITCH1, pitch[1]);
        rotate_write(dev, ROTATE_OUT_PITCH2, pitch[2]);

        rotate_write(dev, ROTATE_OUT_ADDRL0, addr[0]);
        rotate_write(dev, ROTATE_OUT_ADDRL1, addr[1]);
        rotate_write(dev, ROTATE_OUT_ADDRL2, addr[2]);

        rotate_write(dev, ROTATE_OUT_ADDRH0, 0);
        rotate_write(dev, ROTATE_OUT_ADDRH1, 0);
        rotate_write(dev, ROTATE_OUT_ADDRH2, 0);

        rotate_set_bits(dev, ROTATE_INT, ROTATE_INT_FINISH_IRQ_EN);
        rotate_set_bits(dev, ROTATE_GLB_CTL, ROTATE_GLB_CTL_START);
}

static irqreturn_t rotate_irq(int irq, void *data)
{
        struct vb2_v4l2_buffer *buffer;
        struct rotate_dev *dev = data;
        struct rotate_ctx *ctx;
        unsigned int val;

        ctx = v4l2_m2m_get_curr_priv(dev->m2m_dev);
        if (!ctx) {
                v4l2_err(&dev->v4l2_dev,
                         "Instance released before the end of transaction\n");
                return IRQ_NONE;
        }

        val = rotate_read(dev, ROTATE_INT);
        if (!(val & ROTATE_INT_FINISH_IRQ))
                return IRQ_NONE;

        /* clear flag and disable irq */
        rotate_write(dev, ROTATE_INT, ROTATE_INT_FINISH_IRQ);

        buffer = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
        v4l2_m2m_buf_done(buffer, VB2_BUF_STATE_DONE);

        buffer = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
        v4l2_m2m_buf_done(buffer, VB2_BUF_STATE_DONE);

        v4l2_m2m_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx);

        return IRQ_HANDLED;
}

static inline struct rotate_ctx *rotate_file2ctx(struct file *file)
{
        return container_of(file_to_v4l2_fh(file), struct rotate_ctx, fh);
}

static void rotate_prepare_format(struct v4l2_pix_format *pix_fmt)
{
        unsigned int height, width, alignment, sizeimage, size, bpl;
        const struct rotate_format *fmt;
        int i;

        fmt = rotate_find_format(pix_fmt->pixelformat);
        if (!fmt)
                return;

        width = ALIGN(pix_fmt->width, fmt->hsub);
        height = ALIGN(pix_fmt->height, fmt->vsub);

        /* all pitches have to be 16 byte aligned */
        alignment = 16;
        if (fmt->planes > 1)
                alignment *= fmt->hsub / fmt->bpp[1];
        bpl = ALIGN(width * fmt->bpp[0], alignment);

        sizeimage = 0;
        for (i = 0; i < fmt->planes; i++) {
                size = bpl * height;
                if (i > 0) {
                        size *= fmt->bpp[i];
                        size /= fmt->hsub;
                        size /= fmt->vsub;
                }
                sizeimage += size;
        }

        pix_fmt->width = width;
        pix_fmt->height = height;
        pix_fmt->bytesperline = bpl;
        pix_fmt->sizeimage = sizeimage;
}

static int rotate_querycap(struct file *file, void *priv,
                           struct v4l2_capability *cap)
{
        strscpy(cap->driver, ROTATE_NAME, sizeof(cap->driver));
        strscpy(cap->card, ROTATE_NAME, sizeof(cap->card));
        snprintf(cap->bus_info, sizeof(cap->bus_info),
                 "platform:%s", ROTATE_NAME);

        return 0;
}

static int rotate_enum_fmt_vid_cap(struct file *file, void *priv,
                                   struct v4l2_fmtdesc *f)
{
        return rotate_enum_fmt(f, true);
}

static int rotate_enum_fmt_vid_out(struct file *file, void *priv,
                                   struct v4l2_fmtdesc *f)
{
        return rotate_enum_fmt(f, false);
}

static int rotate_enum_framesizes(struct file *file, void *priv,
                                  struct v4l2_frmsizeenum *fsize)
{
        const struct rotate_format *fmt;

        if (fsize->index != 0)
                return -EINVAL;

        fmt = rotate_find_format(fsize->pixel_format);
        if (!fmt)
                return -EINVAL;

        fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
        fsize->stepwise.min_width = ROTATE_MIN_WIDTH;
        fsize->stepwise.min_height = ROTATE_MIN_HEIGHT;
        fsize->stepwise.max_width = ROTATE_MAX_WIDTH;
        fsize->stepwise.max_height = ROTATE_MAX_HEIGHT;
        fsize->stepwise.step_width = fmt->hsub;
        fsize->stepwise.step_height = fmt->vsub;

        return 0;
}

static int rotate_set_cap_format(struct rotate_ctx *ctx,
                                 struct v4l2_pix_format *f,
                                 u32 rotate)
{
        const struct rotate_format *fmt;

        fmt = rotate_find_format(ctx->src_fmt.pixelformat);
        if (!fmt)
                return -EINVAL;

        if (fmt->flags & ROTATE_FLAG_YUV)
                f->pixelformat = V4L2_PIX_FMT_YUV420;
        else
                f->pixelformat = ctx->src_fmt.pixelformat;

        f->field = V4L2_FIELD_NONE;

        if (rotate == 90 || rotate == 270) {
                f->width = ctx->src_fmt.height;
                f->height = ctx->src_fmt.width;
        } else {
                f->width = ctx->src_fmt.width;
                f->height = ctx->src_fmt.height;
        }

        rotate_prepare_format(f);

        return 0;
}

static int rotate_g_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct rotate_ctx *ctx = rotate_file2ctx(file);

        f->fmt.pix = ctx->dst_fmt;

        return 0;
}

static int rotate_g_fmt_vid_out(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct rotate_ctx *ctx = rotate_file2ctx(file);

        f->fmt.pix = ctx->src_fmt;

        return 0;
}

static int rotate_try_fmt_vid_cap(struct file *file, void *priv,
                                  struct v4l2_format *f)
{
        struct rotate_ctx *ctx = rotate_file2ctx(file);

        return rotate_set_cap_format(ctx, &f->fmt.pix, ctx->rotate);
}

static int rotate_try_fmt_vid_out(struct file *file, void *priv,
                                  struct v4l2_format *f)
{
        if (!rotate_find_format(f->fmt.pix.pixelformat))
                f->fmt.pix.pixelformat = V4L2_PIX_FMT_ARGB32;

        if (f->fmt.pix.width < ROTATE_MIN_WIDTH)
                f->fmt.pix.width = ROTATE_MIN_WIDTH;
        if (f->fmt.pix.height < ROTATE_MIN_HEIGHT)
                f->fmt.pix.height = ROTATE_MIN_HEIGHT;

        if (f->fmt.pix.width > ROTATE_MAX_WIDTH)
                f->fmt.pix.width = ROTATE_MAX_WIDTH;
        if (f->fmt.pix.height > ROTATE_MAX_HEIGHT)
                f->fmt.pix.height = ROTATE_MAX_HEIGHT;

        f->fmt.pix.field = V4L2_FIELD_NONE;

        rotate_prepare_format(&f->fmt.pix);

        return 0;
}

static int rotate_s_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct rotate_ctx *ctx = rotate_file2ctx(file);
        struct vb2_queue *vq;
        int ret;

        ret = rotate_try_fmt_vid_cap(file, priv, f);
        if (ret)
                return ret;

        vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
        if (vb2_is_busy(vq))
                return -EBUSY;

        ctx->dst_fmt = f->fmt.pix;

        return 0;
}

static int rotate_s_fmt_vid_out(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct rotate_ctx *ctx = rotate_file2ctx(file);
        struct vb2_queue *vq;
        int ret;

        ret = rotate_try_fmt_vid_out(file, priv, f);
        if (ret)
                return ret;

        vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
        if (vb2_is_busy(vq))
                return -EBUSY;

        /*
         * Capture queue has to be also checked, because format and size
         * depends on output format and size.
         */
        vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
        if (vb2_is_busy(vq))
                return -EBUSY;

        ctx->src_fmt = f->fmt.pix;

        /* Propagate colorspace information to capture. */
        ctx->dst_fmt.colorspace = f->fmt.pix.colorspace;
        ctx->dst_fmt.xfer_func = f->fmt.pix.xfer_func;
        ctx->dst_fmt.ycbcr_enc = f->fmt.pix.ycbcr_enc;
        ctx->dst_fmt.quantization = f->fmt.pix.quantization;

        return rotate_set_cap_format(ctx, &ctx->dst_fmt, ctx->rotate);
}

static const struct v4l2_ioctl_ops rotate_ioctl_ops = {
        .vidioc_querycap                = rotate_querycap,

        .vidioc_enum_framesizes         = rotate_enum_framesizes,

        .vidioc_enum_fmt_vid_cap        = rotate_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap           = rotate_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap         = rotate_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap           = rotate_s_fmt_vid_cap,

        .vidioc_enum_fmt_vid_out        = rotate_enum_fmt_vid_out,
        .vidioc_g_fmt_vid_out           = rotate_g_fmt_vid_out,
        .vidioc_try_fmt_vid_out         = rotate_try_fmt_vid_out,
        .vidioc_s_fmt_vid_out           = rotate_s_fmt_vid_out,

        .vidioc_reqbufs                 = v4l2_m2m_ioctl_reqbufs,
        .vidioc_querybuf                = v4l2_m2m_ioctl_querybuf,
        .vidioc_qbuf                    = v4l2_m2m_ioctl_qbuf,
        .vidioc_dqbuf                   = v4l2_m2m_ioctl_dqbuf,
        .vidioc_prepare_buf             = v4l2_m2m_ioctl_prepare_buf,
        .vidioc_create_bufs             = v4l2_m2m_ioctl_create_bufs,
        .vidioc_expbuf                  = v4l2_m2m_ioctl_expbuf,

        .vidioc_streamon                = v4l2_m2m_ioctl_streamon,
        .vidioc_streamoff               = v4l2_m2m_ioctl_streamoff,

        .vidioc_log_status              = v4l2_ctrl_log_status,
        .vidioc_subscribe_event         = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event       = v4l2_event_unsubscribe,
};

static int rotate_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
                              unsigned int *nplanes, unsigned int sizes[],
                              struct device *alloc_devs[])
{
        struct rotate_ctx *ctx = vb2_get_drv_priv(vq);
        struct v4l2_pix_format *pix_fmt;

        if (V4L2_TYPE_IS_OUTPUT(vq->type))
                pix_fmt = &ctx->src_fmt;
        else
                pix_fmt = &ctx->dst_fmt;

        if (*nplanes) {
                if (sizes[0] < pix_fmt->sizeimage)
                        return -EINVAL;
        } else {
                sizes[0] = pix_fmt->sizeimage;
                *nplanes = 1;
        }

        return 0;
}

static int rotate_buf_prepare(struct vb2_buffer *vb)
{
        struct vb2_queue *vq = vb->vb2_queue;
        struct rotate_ctx *ctx = vb2_get_drv_priv(vq);
        struct v4l2_pix_format *pix_fmt;

        if (V4L2_TYPE_IS_OUTPUT(vq->type))
                pix_fmt = &ctx->src_fmt;
        else
                pix_fmt = &ctx->dst_fmt;

        if (vb2_plane_size(vb, 0) < pix_fmt->sizeimage)
                return -EINVAL;

        vb2_set_plane_payload(vb, 0, pix_fmt->sizeimage);

        return 0;
}

static void rotate_buf_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct rotate_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);

        v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
}

static void rotate_queue_cleanup(struct vb2_queue *vq, u32 state)
{
        struct rotate_ctx *ctx = vb2_get_drv_priv(vq);
        struct vb2_v4l2_buffer *vbuf;

        do {
                if (V4L2_TYPE_IS_OUTPUT(vq->type))
                        vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
                else
                        vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);

                if (vbuf)
                        v4l2_m2m_buf_done(vbuf, state);
        } while (vbuf);
}

static int rotate_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
                struct rotate_ctx *ctx = vb2_get_drv_priv(vq);
                struct device *dev = ctx->dev->dev;
                int ret;

                ret = pm_runtime_resume_and_get(dev);
                if (ret < 0) {
                        dev_err(dev, "Failed to enable module\n");

                        return ret;
                }
        }

        return 0;
}

static void rotate_stop_streaming(struct vb2_queue *vq)
{
        if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
                struct rotate_ctx *ctx = vb2_get_drv_priv(vq);

                pm_runtime_put(ctx->dev->dev);
        }

        rotate_queue_cleanup(vq, VB2_BUF_STATE_ERROR);
}

static const struct vb2_ops rotate_qops = {
        .queue_setup            = rotate_queue_setup,
        .buf_prepare            = rotate_buf_prepare,
        .buf_queue              = rotate_buf_queue,
        .start_streaming        = rotate_start_streaming,
        .stop_streaming         = rotate_stop_streaming,
};

static int rotate_queue_init(void *priv, struct vb2_queue *src_vq,
                             struct vb2_queue *dst_vq)
{
        struct rotate_ctx *ctx = priv;
        int ret;

        src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
        src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
        src_vq->drv_priv = ctx;
        src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
        src_vq->min_queued_buffers = 1;
        src_vq->ops = &rotate_qops;
        src_vq->mem_ops = &vb2_dma_contig_memops;
        src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        src_vq->lock = &ctx->dev->dev_mutex;
        src_vq->dev = ctx->dev->dev;

        ret = vb2_queue_init(src_vq);
        if (ret)
                return ret;

        dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
        dst_vq->drv_priv = ctx;
        dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
        dst_vq->min_queued_buffers = 2;
        dst_vq->ops = &rotate_qops;
        dst_vq->mem_ops = &vb2_dma_contig_memops;
        dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        dst_vq->lock = &ctx->dev->dev_mutex;
        dst_vq->dev = ctx->dev->dev;

        ret = vb2_queue_init(dst_vq);
        if (ret)
                return ret;

        return 0;
}

static int rotate_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct rotate_ctx *ctx = container_of(ctrl->handler,
                                              struct rotate_ctx,
                                              ctrl_handler);
        struct v4l2_pix_format fmt;

        switch (ctrl->id) {
        case V4L2_CID_HFLIP:
                ctx->hflip = ctrl->val;
                break;
        case V4L2_CID_VFLIP:
                ctx->vflip = ctrl->val;
                break;
        case V4L2_CID_ROTATE:
                rotate_set_cap_format(ctx, &fmt, ctrl->val);

                /* Check if capture format needs to be changed */
                if (fmt.width != ctx->dst_fmt.width ||
                    fmt.height != ctx->dst_fmt.height ||
                    fmt.bytesperline != ctx->dst_fmt.bytesperline ||
                    fmt.sizeimage != ctx->dst_fmt.sizeimage) {
                        struct vb2_queue *vq;

                        vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,
                                             V4L2_BUF_TYPE_VIDEO_CAPTURE);
                        if (vb2_is_busy(vq))
                                return -EBUSY;

                        rotate_set_cap_format(ctx, &ctx->dst_fmt, ctrl->val);
                }

                ctx->rotate = ctrl->val;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static const struct v4l2_ctrl_ops rotate_ctrl_ops = {
        .s_ctrl = rotate_s_ctrl,
};

static int rotate_setup_ctrls(struct rotate_ctx *ctx)
{
        v4l2_ctrl_handler_init(&ctx->ctrl_handler, 3);

        v4l2_ctrl_new_std(&ctx->ctrl_handler, &rotate_ctrl_ops,
                          V4L2_CID_HFLIP, 0, 1, 1, 0);

        v4l2_ctrl_new_std(&ctx->ctrl_handler, &rotate_ctrl_ops,
                          V4L2_CID_VFLIP, 0, 1, 1, 0);

        v4l2_ctrl_new_std(&ctx->ctrl_handler, &rotate_ctrl_ops,
                          V4L2_CID_ROTATE, 0, 270, 90, 0);

        if (ctx->ctrl_handler.error) {
                int err = ctx->ctrl_handler.error;

                v4l2_err(&ctx->dev->v4l2_dev, "control setup failed!\n");
                v4l2_ctrl_handler_free(&ctx->ctrl_handler);

                return err;
        }

        return v4l2_ctrl_handler_setup(&ctx->ctrl_handler);
}

static int rotate_open(struct file *file)
{
        struct rotate_dev *dev = video_drvdata(file);
        struct rotate_ctx *ctx = NULL;
        int ret;

        if (mutex_lock_interruptible(&dev->dev_mutex))
                return -ERESTARTSYS;

        ctx = kzalloc_obj(*ctx);
        if (!ctx) {
                mutex_unlock(&dev->dev_mutex);
                return -ENOMEM;
        }

        /* default output format */
        ctx->src_fmt.pixelformat = V4L2_PIX_FMT_ARGB32;
        ctx->src_fmt.field = V4L2_FIELD_NONE;
        ctx->src_fmt.width = 640;
        ctx->src_fmt.height = 480;
        rotate_prepare_format(&ctx->src_fmt);

        /* default capture format */
        rotate_set_cap_format(ctx, &ctx->dst_fmt, ctx->rotate);

        v4l2_fh_init(&ctx->fh, video_devdata(file));
        ctx->dev = dev;

        ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx,
                                            &rotate_queue_init);
        if (IS_ERR(ctx->fh.m2m_ctx)) {
                ret = PTR_ERR(ctx->fh.m2m_ctx);
                goto err_free;
        }

        v4l2_fh_add(&ctx->fh, file);

        ret = rotate_setup_ctrls(ctx);
        if (ret)
                goto err_free;

        ctx->fh.ctrl_handler = &ctx->ctrl_handler;

        mutex_unlock(&dev->dev_mutex);

        return 0;

err_free:
        kfree(ctx);
        mutex_unlock(&dev->dev_mutex);

        return ret;
}

static int rotate_release(struct file *file)
{
        struct rotate_dev *dev = video_drvdata(file);
        struct rotate_ctx *ctx = rotate_file2ctx(file);

        mutex_lock(&dev->dev_mutex);

        v4l2_ctrl_handler_free(&ctx->ctrl_handler);
        v4l2_fh_del(&ctx->fh, file);
        v4l2_fh_exit(&ctx->fh);
        v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);

        kfree(ctx);

        mutex_unlock(&dev->dev_mutex);

        return 0;
}

static const struct v4l2_file_operations rotate_fops = {
        .owner          = THIS_MODULE,
        .open           = rotate_open,
        .release        = rotate_release,
        .poll           = v4l2_m2m_fop_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = v4l2_m2m_fop_mmap,
};

static const struct video_device rotate_video_device = {
        .name           = ROTATE_NAME,
        .vfl_dir        = VFL_DIR_M2M,
        .fops           = &rotate_fops,
        .ioctl_ops      = &rotate_ioctl_ops,
        .minor          = -1,
        .release        = video_device_release_empty,
        .device_caps    = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING,
};

static const struct v4l2_m2m_ops rotate_m2m_ops = {
        .device_run     = rotate_device_run,
};

static int rotate_probe(struct platform_device *pdev)
{
        struct rotate_dev *dev;
        struct video_device *vfd;
        int irq, ret;

        dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;

        dev->vfd = rotate_video_device;
        dev->dev = &pdev->dev;

        irq = platform_get_irq(pdev, 0);
        if (irq <= 0)
                return irq;

        ret = devm_request_irq(dev->dev, irq, rotate_irq,
                               0, dev_name(dev->dev), dev);
        if (ret) {
                dev_err(dev->dev, "Failed to request IRQ\n");

                return ret;
        }

        dev->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(dev->base))
                return PTR_ERR(dev->base);

        dev->bus_clk = devm_clk_get(dev->dev, "bus");
        if (IS_ERR(dev->bus_clk)) {
                dev_err(dev->dev, "Failed to get bus clock\n");

                return PTR_ERR(dev->bus_clk);
        }

        dev->mod_clk = devm_clk_get(dev->dev, "mod");
        if (IS_ERR(dev->mod_clk)) {
                dev_err(dev->dev, "Failed to get mod clock\n");

                return PTR_ERR(dev->mod_clk);
        }

        dev->rstc = devm_reset_control_get(dev->dev, NULL);
        if (IS_ERR(dev->rstc)) {
                dev_err(dev->dev, "Failed to get reset control\n");

                return PTR_ERR(dev->rstc);
        }

        mutex_init(&dev->dev_mutex);

        ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
        if (ret) {
                dev_err(dev->dev, "Failed to register V4L2 device\n");

                return ret;
        }

        vfd = &dev->vfd;
        vfd->lock = &dev->dev_mutex;
        vfd->v4l2_dev = &dev->v4l2_dev;

        snprintf(vfd->name, sizeof(vfd->name), "%s",
                 rotate_video_device.name);
        video_set_drvdata(vfd, dev);

        ret = video_register_device(vfd, VFL_TYPE_VIDEO, 0);
        if (ret) {
                v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");

                goto err_v4l2;
        }

        v4l2_info(&dev->v4l2_dev,
                  "Device registered as /dev/video%d\n", vfd->num);

        dev->m2m_dev = v4l2_m2m_init(&rotate_m2m_ops);
        if (IS_ERR(dev->m2m_dev)) {
                v4l2_err(&dev->v4l2_dev,
                         "Failed to initialize V4L2 M2M device\n");
                ret = PTR_ERR(dev->m2m_dev);

                goto err_video;
        }

        platform_set_drvdata(pdev, dev);

        pm_runtime_enable(dev->dev);

        return 0;

err_video:
        video_unregister_device(&dev->vfd);
err_v4l2:
        v4l2_device_unregister(&dev->v4l2_dev);

        return ret;
}

static void rotate_remove(struct platform_device *pdev)
{
        struct rotate_dev *dev = platform_get_drvdata(pdev);

        v4l2_m2m_release(dev->m2m_dev);
        video_unregister_device(&dev->vfd);
        v4l2_device_unregister(&dev->v4l2_dev);

        pm_runtime_force_suspend(&pdev->dev);
}

static int rotate_runtime_resume(struct device *device)
{
        struct rotate_dev *dev = dev_get_drvdata(device);
        int ret;

        ret = clk_prepare_enable(dev->bus_clk);
        if (ret) {
                dev_err(dev->dev, "Failed to enable bus clock\n");

                return ret;
        }

        ret = clk_prepare_enable(dev->mod_clk);
        if (ret) {
                dev_err(dev->dev, "Failed to enable mod clock\n");

                goto err_bus_clk;
        }

        ret = reset_control_deassert(dev->rstc);
        if (ret) {
                dev_err(dev->dev, "Failed to apply reset\n");

                goto err_mod_clk;
        }

        return 0;

err_mod_clk:
        clk_disable_unprepare(dev->mod_clk);
err_bus_clk:
        clk_disable_unprepare(dev->bus_clk);

        return ret;
}

static int rotate_runtime_suspend(struct device *device)
{
        struct rotate_dev *dev = dev_get_drvdata(device);

        reset_control_assert(dev->rstc);

        clk_disable_unprepare(dev->mod_clk);
        clk_disable_unprepare(dev->bus_clk);

        return 0;
}

static const struct of_device_id rotate_dt_match[] = {
        { .compatible = "allwinner,sun8i-a83t-de2-rotate" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rotate_dt_match);

static const struct dev_pm_ops rotate_pm_ops = {
        .runtime_resume         = rotate_runtime_resume,
        .runtime_suspend        = rotate_runtime_suspend,
};

static struct platform_driver rotate_driver = {
        .probe          = rotate_probe,
        .remove         = rotate_remove,
        .driver         = {
                .name           = ROTATE_NAME,
                .of_match_table = rotate_dt_match,
                .pm             = &rotate_pm_ops,
        },
};
module_platform_driver(rotate_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Jernej Skrabec <jernej.skrabec@siol.net>");
MODULE_DESCRIPTION("Allwinner DE2 rotate driver");