root/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_capture.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
 * Author: Yong Deng <yong.deng@magewell.com>
 * Copyright 2021-2022 Bootlin
 * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 */

#include <linux/of.h>
#include <linux/regmap.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mc.h>
#include <media/videobuf2-dma-contig.h>
#include <media/videobuf2-v4l2.h>

#include "sun6i_csi.h"
#include "sun6i_csi_bridge.h"
#include "sun6i_csi_capture.h"
#include "sun6i_csi_reg.h"

/* Helpers */

void sun6i_csi_capture_dimensions(struct sun6i_csi_device *csi_dev,
                                  unsigned int *width, unsigned int *height)
{
        if (width)
                *width = csi_dev->capture.format.fmt.pix.width;
        if (height)
                *height = csi_dev->capture.format.fmt.pix.height;
}

void sun6i_csi_capture_format(struct sun6i_csi_device *csi_dev,
                              u32 *pixelformat, u32 *field)
{
        if (pixelformat)
                *pixelformat = csi_dev->capture.format.fmt.pix.pixelformat;

        if (field)
                *field = csi_dev->capture.format.fmt.pix.field;
}

/* Format */

static const struct sun6i_csi_capture_format sun6i_csi_capture_formats[] = {
        /* Bayer */
        {
                .pixelformat            = V4L2_PIX_FMT_SBGGR8,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SGBRG8,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SGRBG8,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SRGGB8,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SBGGR10,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_10,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_10,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SGBRG10,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_10,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_10,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SGRBG10,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_10,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_10,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SRGGB10,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_10,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_10,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SBGGR12,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_12,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_12,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SGBRG12,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_12,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_12,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SGRBG12,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_12,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_12,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_SRGGB12,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_12,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_12,
        },
        /* RGB */
        {
                .pixelformat            = V4L2_PIX_FMT_RGB565,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RGB565,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RGB565,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_RGB565X,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RGB565,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RGB565,
        },
        /* YUV422 */
        {
                .pixelformat            = V4L2_PIX_FMT_YUYV,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
                .input_format_raw       = true,
                .hsize_len_factor       = 2,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_YVYU,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
                .input_format_raw       = true,
                .hsize_len_factor       = 2,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_UYVY,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
                .input_format_raw       = true,
                .hsize_len_factor       = 2,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_VYUY,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
                .input_format_raw       = true,
                .hsize_len_factor       = 2,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_NV16,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV422SP,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV422SP,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_NV61,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV422SP,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV422SP,
                .input_yuv_seq_invert   = true,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_YUV422P,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV422P,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV422P,
        },
        /* YUV420 */
        {
                .pixelformat            = V4L2_PIX_FMT_NV12_16L16,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV420MB,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV420MB,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_NV12,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV420SP,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV420SP,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_NV21,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV420SP,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV420SP,
                .input_yuv_seq_invert   = true,
        },

        {
                .pixelformat            = V4L2_PIX_FMT_YUV420,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV420P,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV420P,
        },
        {
                .pixelformat            = V4L2_PIX_FMT_YVU420,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_YUV420P,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_YUV420P,
                .input_yuv_seq_invert   = true,
        },
        /* Compressed */
        {
                .pixelformat            = V4L2_PIX_FMT_JPEG,
                .output_format_frame    = SUN6I_CSI_OUTPUT_FMT_FRAME_RAW_8,
                .output_format_field    = SUN6I_CSI_OUTPUT_FMT_FIELD_RAW_8,
        },
};

const
struct sun6i_csi_capture_format *sun6i_csi_capture_format_find(u32 pixelformat)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(sun6i_csi_capture_formats); i++)
                if (sun6i_csi_capture_formats[i].pixelformat == pixelformat)
                        return &sun6i_csi_capture_formats[i];

        return NULL;
}

/* RAW formats need an exact match between pixel and mbus formats. */
static const
struct sun6i_csi_capture_format_match sun6i_csi_capture_format_matches[] = {
        /* YUV420 */
        {
                .pixelformat    = V4L2_PIX_FMT_YUYV,
                .mbus_code      = MEDIA_BUS_FMT_YUYV8_2X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_YUYV,
                .mbus_code      = MEDIA_BUS_FMT_YUYV8_1X16,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_YVYU,
                .mbus_code      = MEDIA_BUS_FMT_YVYU8_2X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_YVYU,
                .mbus_code      = MEDIA_BUS_FMT_YVYU8_1X16,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_UYVY,
                .mbus_code      = MEDIA_BUS_FMT_UYVY8_2X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_UYVY,
                .mbus_code      = MEDIA_BUS_FMT_UYVY8_1X16,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_VYUY,
                .mbus_code      = MEDIA_BUS_FMT_VYUY8_2X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_VYUY,
                .mbus_code      = MEDIA_BUS_FMT_VYUY8_1X16,
        },
        /* RGB */
        {
                .pixelformat    = V4L2_PIX_FMT_RGB565,
                .mbus_code      = MEDIA_BUS_FMT_RGB565_2X8_LE,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_RGB565X,
                .mbus_code      = MEDIA_BUS_FMT_RGB565_2X8_BE,
        },
        /* Bayer */
        {
                .pixelformat    = V4L2_PIX_FMT_SBGGR8,
                .mbus_code      = MEDIA_BUS_FMT_SBGGR8_1X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SGBRG8,
                .mbus_code      = MEDIA_BUS_FMT_SGBRG8_1X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SGRBG8,
                .mbus_code      = MEDIA_BUS_FMT_SGRBG8_1X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SRGGB8,
                .mbus_code      = MEDIA_BUS_FMT_SRGGB8_1X8,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SBGGR10,
                .mbus_code      = MEDIA_BUS_FMT_SBGGR10_1X10,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SGBRG10,
                .mbus_code      = MEDIA_BUS_FMT_SGBRG10_1X10,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SGRBG10,
                .mbus_code      = MEDIA_BUS_FMT_SGRBG10_1X10,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SRGGB10,
                .mbus_code      = MEDIA_BUS_FMT_SRGGB10_1X10,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SBGGR12,
                .mbus_code      = MEDIA_BUS_FMT_SBGGR12_1X12,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SGBRG12,
                .mbus_code      = MEDIA_BUS_FMT_SGBRG12_1X12,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SGRBG12,
                .mbus_code      = MEDIA_BUS_FMT_SGRBG12_1X12,
        },
        {
                .pixelformat    = V4L2_PIX_FMT_SRGGB12,
                .mbus_code      = MEDIA_BUS_FMT_SRGGB12_1X12,
        },
        /* Compressed */
        {
                .pixelformat    = V4L2_PIX_FMT_JPEG,
                .mbus_code      = MEDIA_BUS_FMT_JPEG_1X8,
        },
};

static bool sun6i_csi_capture_format_match(u32 pixelformat, u32 mbus_code)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(sun6i_csi_capture_format_matches); i++) {
                const struct sun6i_csi_capture_format_match *match =
                        &sun6i_csi_capture_format_matches[i];

                if (match->pixelformat == pixelformat &&
                    match->mbus_code == mbus_code)
                        return true;
        }

        return false;
}

/* Capture */

static void
sun6i_csi_capture_buffer_configure(struct sun6i_csi_device *csi_dev,
                                   struct sun6i_csi_buffer *csi_buffer)
{
        struct regmap *regmap = csi_dev->regmap;
        const struct v4l2_format_info *info;
        struct vb2_buffer *vb2_buffer;
        unsigned int width, height;
        dma_addr_t address;
        u32 pixelformat;

        vb2_buffer = &csi_buffer->v4l2_buffer.vb2_buf;
        address = vb2_dma_contig_plane_dma_addr(vb2_buffer, 0);

        regmap_write(regmap, SUN6I_CSI_CH_FIFO0_ADDR_REG,
                     SUN6I_CSI_ADDR_VALUE(address));

        sun6i_csi_capture_dimensions(csi_dev, &width, &height);
        sun6i_csi_capture_format(csi_dev, &pixelformat, NULL);

        info = v4l2_format_info(pixelformat);
        /* Unsupported formats are single-plane, so we can stop here. */
        if (!info)
                return;

        if (info->comp_planes > 1) {
                address += info->bpp[0] * width * height;

                regmap_write(regmap, SUN6I_CSI_CH_FIFO1_ADDR_REG,
                             SUN6I_CSI_ADDR_VALUE(address));
        }

        if (info->comp_planes > 2) {
                address += info->bpp[1] * DIV_ROUND_UP(width, info->hdiv) *
                           DIV_ROUND_UP(height, info->vdiv);

                regmap_write(regmap, SUN6I_CSI_CH_FIFO2_ADDR_REG,
                             SUN6I_CSI_ADDR_VALUE(address));
        }
}

void sun6i_csi_capture_configure(struct sun6i_csi_device *csi_dev)
{
        struct regmap *regmap = csi_dev->regmap;
        const struct sun6i_csi_capture_format *format;
        const struct v4l2_format_info *info;
        u32 hsize_len, vsize_len;
        u32 luma_line, chroma_line = 0;
        u32 pixelformat, field;
        u32 width, height;

        sun6i_csi_capture_dimensions(csi_dev, &width, &height);
        sun6i_csi_capture_format(csi_dev, &pixelformat, &field);

        format = sun6i_csi_capture_format_find(pixelformat);
        if (WARN_ON(!format))
                return;

        hsize_len = width;
        vsize_len = height;

        /*
         * When using 8-bit raw input/output (for packed YUV), we need to adapt
         * the width to account for the difference in bpp when it's not 8-bit.
         */
        if (format->hsize_len_factor)
                hsize_len *= format->hsize_len_factor;

        regmap_write(regmap, SUN6I_CSI_CH_HSIZE_REG,
                     SUN6I_CSI_CH_HSIZE_LEN(hsize_len) |
                     SUN6I_CSI_CH_HSIZE_START(0));

        regmap_write(regmap, SUN6I_CSI_CH_VSIZE_REG,
                     SUN6I_CSI_CH_VSIZE_LEN(vsize_len) |
                     SUN6I_CSI_CH_VSIZE_START(0));

        switch (pixelformat) {
        case V4L2_PIX_FMT_RGB565X:
                luma_line = width * 2;
                break;
        case V4L2_PIX_FMT_NV12_16L16:
                luma_line = width;
                chroma_line = width;
                break;
        case V4L2_PIX_FMT_JPEG:
                luma_line = width;
                break;
        default:
                info = v4l2_format_info(pixelformat);
                if (WARN_ON(!info))
                        return;

                luma_line = width * info->bpp[0];

                if (info->comp_planes > 1)
                        chroma_line = width * info->bpp[1] / info->hdiv;
                break;
        }

        regmap_write(regmap, SUN6I_CSI_CH_BUF_LEN_REG,
                     SUN6I_CSI_CH_BUF_LEN_CHROMA_LINE(chroma_line) |
                     SUN6I_CSI_CH_BUF_LEN_LUMA_LINE(luma_line));
}

/* State */

static void sun6i_csi_capture_state_cleanup(struct sun6i_csi_device *csi_dev,
                                            bool error)
{
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        struct sun6i_csi_buffer **csi_buffer_states[] = {
                &state->pending, &state->current, &state->complete,
        };
        struct sun6i_csi_buffer *csi_buffer;
        struct vb2_buffer *vb2_buffer;
        unsigned long flags;
        unsigned int i;

        spin_lock_irqsave(&state->lock, flags);

        for (i = 0; i < ARRAY_SIZE(csi_buffer_states); i++) {
                csi_buffer = *csi_buffer_states[i];
                if (!csi_buffer)
                        continue;

                vb2_buffer = &csi_buffer->v4l2_buffer.vb2_buf;
                vb2_buffer_done(vb2_buffer, error ? VB2_BUF_STATE_ERROR :
                                VB2_BUF_STATE_QUEUED);

                *csi_buffer_states[i] = NULL;
        }

        list_for_each_entry(csi_buffer, &state->queue, list) {
                vb2_buffer = &csi_buffer->v4l2_buffer.vb2_buf;
                vb2_buffer_done(vb2_buffer, error ? VB2_BUF_STATE_ERROR :
                                VB2_BUF_STATE_QUEUED);
        }

        INIT_LIST_HEAD(&state->queue);

        spin_unlock_irqrestore(&state->lock, flags);
}

void sun6i_csi_capture_state_update(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        struct sun6i_csi_buffer *csi_buffer;
        unsigned long flags;

        spin_lock_irqsave(&state->lock, flags);

        if (list_empty(&state->queue))
                goto complete;

        if (state->pending)
                goto complete;

        csi_buffer = list_first_entry(&state->queue, struct sun6i_csi_buffer,
                                      list);

        sun6i_csi_capture_buffer_configure(csi_dev, csi_buffer);

        list_del(&csi_buffer->list);

        state->pending = csi_buffer;

complete:
        spin_unlock_irqrestore(&state->lock, flags);
}

static void sun6i_csi_capture_state_complete(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        unsigned long flags;

        spin_lock_irqsave(&state->lock, flags);

        if (!state->pending)
                goto complete;

        state->complete = state->current;
        state->current = state->pending;
        state->pending = NULL;

        if (state->complete) {
                struct sun6i_csi_buffer *csi_buffer = state->complete;
                struct vb2_buffer *vb2_buffer =
                        &csi_buffer->v4l2_buffer.vb2_buf;

                vb2_buffer->timestamp = ktime_get_ns();
                csi_buffer->v4l2_buffer.sequence = state->sequence;

                vb2_buffer_done(vb2_buffer, VB2_BUF_STATE_DONE);

                state->complete = NULL;
        }

complete:
        spin_unlock_irqrestore(&state->lock, flags);
}

void sun6i_csi_capture_frame_done(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        unsigned long flags;

        spin_lock_irqsave(&state->lock, flags);
        state->sequence++;
        spin_unlock_irqrestore(&state->lock, flags);
}

void sun6i_csi_capture_sync(struct sun6i_csi_device *csi_dev)
{
        sun6i_csi_capture_state_complete(csi_dev);
        sun6i_csi_capture_state_update(csi_dev);
}

/* Queue */

static int sun6i_csi_capture_queue_setup(struct vb2_queue *queue,
                                         unsigned int *buffers_count,
                                         unsigned int *planes_count,
                                         unsigned int sizes[],
                                         struct device *alloc_devs[])
{
        struct sun6i_csi_device *csi_dev = vb2_get_drv_priv(queue);
        unsigned int size = csi_dev->capture.format.fmt.pix.sizeimage;

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

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

        return 0;
}

static int sun6i_csi_capture_buffer_prepare(struct vb2_buffer *buffer)
{
        struct sun6i_csi_device *csi_dev = vb2_get_drv_priv(buffer->vb2_queue);
        struct sun6i_csi_capture *capture = &csi_dev->capture;
        struct v4l2_device *v4l2_dev = csi_dev->v4l2_dev;
        struct vb2_v4l2_buffer *v4l2_buffer = to_vb2_v4l2_buffer(buffer);
        unsigned long size = capture->format.fmt.pix.sizeimage;

        if (vb2_plane_size(buffer, 0) < size) {
                v4l2_err(v4l2_dev, "buffer too small (%lu < %lu)\n",
                         vb2_plane_size(buffer, 0), size);
                return -EINVAL;
        }

        vb2_set_plane_payload(buffer, 0, size);

        v4l2_buffer->field = capture->format.fmt.pix.field;

        return 0;
}

static void sun6i_csi_capture_buffer_queue(struct vb2_buffer *buffer)
{
        struct sun6i_csi_device *csi_dev = vb2_get_drv_priv(buffer->vb2_queue);
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        struct vb2_v4l2_buffer *v4l2_buffer = to_vb2_v4l2_buffer(buffer);
        struct sun6i_csi_buffer *csi_buffer =
                container_of(v4l2_buffer, struct sun6i_csi_buffer, v4l2_buffer);
        unsigned long flags;

        spin_lock_irqsave(&state->lock, flags);
        list_add_tail(&csi_buffer->list, &state->queue);
        spin_unlock_irqrestore(&state->lock, flags);
}

static int sun6i_csi_capture_start_streaming(struct vb2_queue *queue,
                                             unsigned int count)
{
        struct sun6i_csi_device *csi_dev = vb2_get_drv_priv(queue);
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        struct video_device *video_dev = &csi_dev->capture.video_dev;
        struct v4l2_subdev *subdev = &csi_dev->bridge.subdev;
        int ret;

        state->sequence = 0;

        ret = video_device_pipeline_alloc_start(video_dev);
        if (ret < 0)
                goto error_state;

        state->streaming = true;

        ret = v4l2_subdev_call(subdev, video, s_stream, 1);
        if (ret && ret != -ENOIOCTLCMD)
                goto error_streaming;

        return 0;

error_streaming:
        state->streaming = false;

        video_device_pipeline_stop(video_dev);

error_state:
        sun6i_csi_capture_state_cleanup(csi_dev, false);

        return ret;
}

static void sun6i_csi_capture_stop_streaming(struct vb2_queue *queue)
{
        struct sun6i_csi_device *csi_dev = vb2_get_drv_priv(queue);
        struct sun6i_csi_capture_state *state = &csi_dev->capture.state;
        struct video_device *video_dev = &csi_dev->capture.video_dev;
        struct v4l2_subdev *subdev = &csi_dev->bridge.subdev;

        v4l2_subdev_call(subdev, video, s_stream, 0);

        state->streaming = false;

        video_device_pipeline_stop(video_dev);

        sun6i_csi_capture_state_cleanup(csi_dev, true);
}

static const struct vb2_ops sun6i_csi_capture_queue_ops = {
        .queue_setup            = sun6i_csi_capture_queue_setup,
        .buf_prepare            = sun6i_csi_capture_buffer_prepare,
        .buf_queue              = sun6i_csi_capture_buffer_queue,
        .start_streaming        = sun6i_csi_capture_start_streaming,
        .stop_streaming         = sun6i_csi_capture_stop_streaming,
};

/* V4L2 Device */

static void sun6i_csi_capture_format_prepare(struct v4l2_format *format)
{
        struct v4l2_pix_format *pix_format = &format->fmt.pix;
        const struct v4l2_format_info *info;
        unsigned int width, height;

        v4l_bound_align_image(&pix_format->width, SUN6I_CSI_CAPTURE_WIDTH_MIN,
                              SUN6I_CSI_CAPTURE_WIDTH_MAX, 1,
                              &pix_format->height, SUN6I_CSI_CAPTURE_HEIGHT_MIN,
                              SUN6I_CSI_CAPTURE_HEIGHT_MAX, 1, 0);

        if (!sun6i_csi_capture_format_find(pix_format->pixelformat))
                pix_format->pixelformat =
                        sun6i_csi_capture_formats[0].pixelformat;

        width = pix_format->width;
        height = pix_format->height;

        info = v4l2_format_info(pix_format->pixelformat);

        switch (pix_format->pixelformat) {
        case V4L2_PIX_FMT_NV12_16L16:
                pix_format->bytesperline = width * 12 / 8;
                pix_format->sizeimage = pix_format->bytesperline * height;
                break;
        case V4L2_PIX_FMT_JPEG:
                pix_format->bytesperline = width;
                pix_format->sizeimage = pix_format->bytesperline * height;
                break;
        default:
                v4l2_fill_pixfmt(pix_format, pix_format->pixelformat,
                                 width, height);
                break;
        }

        if (pix_format->field == V4L2_FIELD_ANY)
                pix_format->field = V4L2_FIELD_NONE;

        if (pix_format->pixelformat == V4L2_PIX_FMT_JPEG)
                pix_format->colorspace = V4L2_COLORSPACE_JPEG;
        else if (info && info->pixel_enc == V4L2_PIXEL_ENC_BAYER)
                pix_format->colorspace = V4L2_COLORSPACE_RAW;
        else
                pix_format->colorspace = V4L2_COLORSPACE_SRGB;

        pix_format->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
        pix_format->quantization = V4L2_QUANTIZATION_DEFAULT;
        pix_format->xfer_func = V4L2_XFER_FUNC_DEFAULT;
}

static int sun6i_csi_capture_querycap(struct file *file, void *priv,
                                      struct v4l2_capability *capability)
{
        struct sun6i_csi_device *csi_dev = video_drvdata(file);
        struct video_device *video_dev = &csi_dev->capture.video_dev;

        strscpy(capability->driver, SUN6I_CSI_NAME, sizeof(capability->driver));
        strscpy(capability->card, video_dev->name, sizeof(capability->card));
        snprintf(capability->bus_info, sizeof(capability->bus_info),
                 "platform:%s", dev_name(csi_dev->dev));

        return 0;
}

static int sun6i_csi_capture_enum_fmt(struct file *file, void *priv,
                                      struct v4l2_fmtdesc *fmtdesc)
{
        u32 index = fmtdesc->index;

        if (index >= ARRAY_SIZE(sun6i_csi_capture_formats))
                return -EINVAL;

        fmtdesc->pixelformat = sun6i_csi_capture_formats[index].pixelformat;

        return 0;
}

static int sun6i_csi_capture_g_fmt(struct file *file, void *priv,
                                   struct v4l2_format *format)
{
        struct sun6i_csi_device *csi_dev = video_drvdata(file);

        *format = csi_dev->capture.format;

        return 0;
}

static int sun6i_csi_capture_s_fmt(struct file *file, void *priv,
                                   struct v4l2_format *format)
{
        struct sun6i_csi_device *csi_dev = video_drvdata(file);
        struct sun6i_csi_capture *capture = &csi_dev->capture;

        if (vb2_is_busy(&capture->queue))
                return -EBUSY;

        sun6i_csi_capture_format_prepare(format);

        csi_dev->capture.format = *format;

        return 0;
}

static int sun6i_csi_capture_try_fmt(struct file *file, void *priv,
                                     struct v4l2_format *format)
{
        sun6i_csi_capture_format_prepare(format);

        return 0;
}

static int sun6i_csi_capture_enum_input(struct file *file, void *priv,
                                        struct v4l2_input *input)
{
        if (input->index != 0)
                return -EINVAL;

        input->type = V4L2_INPUT_TYPE_CAMERA;
        strscpy(input->name, "Camera", sizeof(input->name));

        return 0;
}

static int sun6i_csi_capture_g_input(struct file *file, void *priv,
                                     unsigned int *index)
{
        *index = 0;

        return 0;
}

static int sun6i_csi_capture_s_input(struct file *file, void *priv,
                                     unsigned int index)
{
        if (index != 0)
                return -EINVAL;

        return 0;
}

static const struct v4l2_ioctl_ops sun6i_csi_capture_ioctl_ops = {
        .vidioc_querycap                = sun6i_csi_capture_querycap,

        .vidioc_enum_fmt_vid_cap        = sun6i_csi_capture_enum_fmt,
        .vidioc_g_fmt_vid_cap           = sun6i_csi_capture_g_fmt,
        .vidioc_s_fmt_vid_cap           = sun6i_csi_capture_s_fmt,
        .vidioc_try_fmt_vid_cap         = sun6i_csi_capture_try_fmt,

        .vidioc_enum_input              = sun6i_csi_capture_enum_input,
        .vidioc_g_input                 = sun6i_csi_capture_g_input,
        .vidioc_s_input                 = sun6i_csi_capture_s_input,

        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_expbuf                  = vb2_ioctl_expbuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,
};

/* V4L2 File */

static int sun6i_csi_capture_open(struct file *file)
{
        struct sun6i_csi_device *csi_dev = video_drvdata(file);
        struct sun6i_csi_capture *capture = &csi_dev->capture;
        int ret;

        if (mutex_lock_interruptible(&capture->lock))
                return -ERESTARTSYS;

        ret = v4l2_pipeline_pm_get(&capture->video_dev.entity);
        if (ret < 0)
                goto error_lock;

        ret = v4l2_fh_open(file);
        if (ret < 0)
                goto error_pipeline;

        mutex_unlock(&capture->lock);

        return 0;

error_pipeline:
        v4l2_pipeline_pm_put(&capture->video_dev.entity);

error_lock:
        mutex_unlock(&capture->lock);

        return ret;
}

static int sun6i_csi_capture_close(struct file *file)
{
        struct sun6i_csi_device *csi_dev = video_drvdata(file);
        struct sun6i_csi_capture *capture = &csi_dev->capture;

        mutex_lock(&capture->lock);

        _vb2_fop_release(file, NULL);
        v4l2_pipeline_pm_put(&capture->video_dev.entity);

        mutex_unlock(&capture->lock);

        return 0;
}

static const struct v4l2_file_operations sun6i_csi_capture_fops = {
        .owner          = THIS_MODULE,
        .open           = sun6i_csi_capture_open,
        .release        = sun6i_csi_capture_close,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = vb2_fop_mmap,
        .poll           = vb2_fop_poll
};

/* Media Entity */

static int sun6i_csi_capture_link_validate(struct media_link *link)
{
        struct video_device *video_dev =
                media_entity_to_video_device(link->sink->entity);
        struct sun6i_csi_device *csi_dev = video_get_drvdata(video_dev);
        struct v4l2_device *v4l2_dev = csi_dev->v4l2_dev;
        const struct sun6i_csi_capture_format *capture_format;
        const struct sun6i_csi_bridge_format *bridge_format;
        unsigned int capture_width, capture_height;
        unsigned int bridge_width, bridge_height;
        const struct v4l2_format_info *format_info;
        u32 pixelformat, capture_field;
        u32 mbus_code, bridge_field;
        bool match;

        sun6i_csi_capture_dimensions(csi_dev, &capture_width, &capture_height);

        sun6i_csi_capture_format(csi_dev, &pixelformat, &capture_field);
        capture_format = sun6i_csi_capture_format_find(pixelformat);
        if (WARN_ON(!capture_format))
                return -EINVAL;

        sun6i_csi_bridge_dimensions(csi_dev, &bridge_width, &bridge_height);

        sun6i_csi_bridge_format(csi_dev, &mbus_code, &bridge_field);
        bridge_format = sun6i_csi_bridge_format_find(mbus_code);
        if (WARN_ON(!bridge_format))
                return -EINVAL;

        /* No cropping/scaling is supported. */
        if (capture_width != bridge_width || capture_height != bridge_height) {
                v4l2_err(v4l2_dev,
                         "invalid input/output dimensions: %ux%u/%ux%u\n",
                         bridge_width, bridge_height, capture_width,
                         capture_height);
                return -EINVAL;
        }

        format_info = v4l2_format_info(pixelformat);
        /* Some formats are not listed. */
        if (!format_info)
                return 0;

        if (format_info->pixel_enc == V4L2_PIXEL_ENC_BAYER &&
            bridge_format->input_format != SUN6I_CSI_INPUT_FMT_RAW)
                goto invalid;

        if (format_info->pixel_enc == V4L2_PIXEL_ENC_RGB &&
            bridge_format->input_format != SUN6I_CSI_INPUT_FMT_RAW)
                goto invalid;

        if (format_info->pixel_enc == V4L2_PIXEL_ENC_YUV) {
                if (bridge_format->input_format != SUN6I_CSI_INPUT_FMT_YUV420 &&
                    bridge_format->input_format != SUN6I_CSI_INPUT_FMT_YUV422)
                        goto invalid;

                /* YUV420 input can't produce YUV422 output. */
                if (bridge_format->input_format == SUN6I_CSI_INPUT_FMT_YUV420 &&
                    format_info->vdiv == 1)
                        goto invalid;
        }

        /* With raw input mode, we need a 1:1 match between input and output. */
        if (bridge_format->input_format == SUN6I_CSI_INPUT_FMT_RAW ||
            capture_format->input_format_raw) {
                match = sun6i_csi_capture_format_match(pixelformat, mbus_code);
                if (!match)
                        goto invalid;
        }

        return 0;

invalid:
        v4l2_err(v4l2_dev, "invalid input/output format combination\n");
        return -EINVAL;
}

static const struct media_entity_operations sun6i_csi_capture_media_ops = {
        .link_validate = sun6i_csi_capture_link_validate
};

/* Capture */

int sun6i_csi_capture_setup(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_capture *capture = &csi_dev->capture;
        struct sun6i_csi_capture_state *state = &capture->state;
        struct v4l2_device *v4l2_dev = csi_dev->v4l2_dev;
        struct v4l2_subdev *bridge_subdev = &csi_dev->bridge.subdev;
        struct video_device *video_dev = &capture->video_dev;
        struct vb2_queue *queue = &capture->queue;
        struct media_pad *pad = &capture->pad;
        struct v4l2_format *format = &csi_dev->capture.format;
        struct v4l2_pix_format *pix_format = &format->fmt.pix;
        int ret;

        /* This may happen with multiple bridge notifier bound calls. */
        if (state->setup)
                return 0;

        /* State */

        INIT_LIST_HEAD(&state->queue);
        spin_lock_init(&state->lock);

        /* Media Entity */

        video_dev->entity.ops = &sun6i_csi_capture_media_ops;

        /* Media Pad */

        pad->flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;

        ret = media_entity_pads_init(&video_dev->entity, 1, pad);
        if (ret < 0)
                return ret;

        /* Queue */

        mutex_init(&capture->lock);

        queue->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        queue->io_modes = VB2_MMAP | VB2_DMABUF;
        queue->buf_struct_size = sizeof(struct sun6i_csi_buffer);
        queue->ops = &sun6i_csi_capture_queue_ops;
        queue->mem_ops = &vb2_dma_contig_memops;
        queue->min_queued_buffers = 2;
        queue->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        queue->lock = &capture->lock;
        queue->dev = csi_dev->dev;
        queue->drv_priv = csi_dev;

        ret = vb2_queue_init(queue);
        if (ret) {
                v4l2_err(v4l2_dev, "failed to initialize vb2 queue: %d\n", ret);
                goto error_media_entity;
        }

        /* V4L2 Format */

        format->type = queue->type;
        pix_format->pixelformat = sun6i_csi_capture_formats[0].pixelformat;
        pix_format->width = 1280;
        pix_format->height = 720;
        pix_format->field = V4L2_FIELD_NONE;

        sun6i_csi_capture_format_prepare(format);

        /* Video Device */

        strscpy(video_dev->name, SUN6I_CSI_CAPTURE_NAME,
                sizeof(video_dev->name));
        video_dev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
        video_dev->vfl_dir = VFL_DIR_RX;
        video_dev->release = video_device_release_empty;
        video_dev->fops = &sun6i_csi_capture_fops;
        video_dev->ioctl_ops = &sun6i_csi_capture_ioctl_ops;
        video_dev->v4l2_dev = v4l2_dev;
        video_dev->queue = queue;
        video_dev->lock = &capture->lock;

        video_set_drvdata(video_dev, csi_dev);

        ret = video_register_device(video_dev, VFL_TYPE_VIDEO, -1);
        if (ret < 0) {
                v4l2_err(v4l2_dev, "failed to register video device: %d\n",
                         ret);
                goto error_media_entity;
        }

        /* Media Pad Link */

        ret = media_create_pad_link(&bridge_subdev->entity,
                                    SUN6I_CSI_BRIDGE_PAD_SOURCE,
                                    &video_dev->entity, 0,
                                    csi_dev->isp_available ? 0 :
                                    MEDIA_LNK_FL_ENABLED |
                                    MEDIA_LNK_FL_IMMUTABLE);
        if (ret < 0) {
                v4l2_err(v4l2_dev, "failed to create %s:%u -> %s:%u link\n",
                         bridge_subdev->entity.name,
                         SUN6I_CSI_BRIDGE_PAD_SOURCE,
                         video_dev->entity.name, 0);
                goto error_video_device;
        }

        state->setup = true;

        return 0;

error_video_device:
        vb2_video_unregister_device(video_dev);

error_media_entity:
        media_entity_cleanup(&video_dev->entity);

        mutex_destroy(&capture->lock);

        return ret;
}

void sun6i_csi_capture_cleanup(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_capture *capture = &csi_dev->capture;
        struct video_device *video_dev = &capture->video_dev;

        /* This may happen if async registration failed to complete. */
        if (!capture->state.setup)
                return;

        vb2_video_unregister_device(video_dev);
        media_entity_cleanup(&video_dev->entity);
        mutex_destroy(&capture->lock);

        capture->state.setup = false;
}