// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2011 Atmel Corporation
 * Josh Wu, <josh.wu@atmel.com>
 *
 * Based on previous work by Lars Haring, <lars.haring@atmel.com>
 * and Sedji Gaouaou
 * Based on the bttv driver for Bt848 with respective copyright holders
 */

#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/of.h>

#include <linux/videodev2.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-event.h>
#include <media/v4l2-fwnode.h>
#include <media/videobuf2-dma-contig.h>
#include <media/v4l2-image-sizes.h>

#include "atmel-isi.h"

#define MAX_SUPPORT_WIDTH               2048U
#define MAX_SUPPORT_HEIGHT              2048U
#define MIN_FRAME_RATE                  15
#define FRAME_INTERVAL_MILLI_SEC        (1000 / MIN_FRAME_RATE)

/* Frame buffer descriptor */
struct fbd {
        /* Physical address of the frame buffer */
        u32 fb_address;
        /* DMA Control Register(only in HISI2) */
        u32 dma_ctrl;
        /* Physical address of the next fbd */
        u32 next_fbd_address;
};

static void set_dma_ctrl(struct fbd *fb_desc, u32 ctrl)
{
        fb_desc->dma_ctrl = ctrl;
}

struct isi_dma_desc {
        struct list_head list;
        struct fbd *p_fbd;
        dma_addr_t fbd_phys;
};

/* Frame buffer data */
struct frame_buffer {
        struct vb2_v4l2_buffer vb;
        struct isi_dma_desc *p_dma_desc;
        struct list_head list;
};

struct isi_graph_entity {
        struct device_node *node;

        struct v4l2_subdev *subdev;
};

/*
 * struct isi_format - ISI media bus format information
 * @fourcc:             Fourcc code for this format
 * @mbus_code:          V4L2 media bus format code.
 * @bpp:                Bytes per pixel (when stored in memory)
 * @swap:               Byte swap configuration value
 * @support:            Indicates format supported by subdev
 * @skip:               Skip duplicate format supported by subdev
 */
struct isi_format {
        u32     fourcc;
        u32     mbus_code;
        u8      bpp;
        u32     swap;
};


struct atmel_isi {
        /* Protects the access of variables shared with the ISR */
        spinlock_t                      irqlock;
        struct device                   *dev;
        void __iomem                    *regs;

        int                             sequence;

        /* Allocate descriptors for dma buffer use */
        struct fbd                      *p_fb_descriptors;
        dma_addr_t                      fb_descriptors_phys;
        struct                          list_head dma_desc_head;
        struct isi_dma_desc             dma_desc[VIDEO_MAX_FRAME];
        bool                            enable_preview_path;

        struct completion               complete;
        /* ISI peripheral clock */
        struct clk                      *pclk;
        unsigned int                    irq;

        struct isi_platform_data        pdata;
        u16                             width_flags;    /* max 12 bits */

        struct list_head                video_buffer_list;
        struct frame_buffer             *active;

        struct v4l2_device              v4l2_dev;
        struct video_device             *vdev;
        struct v4l2_async_notifier      notifier;
        struct isi_graph_entity         entity;
        struct v4l2_format              fmt;

        const struct isi_format         **user_formats;
        unsigned int                    num_user_formats;
        const struct isi_format         *current_fmt;

        struct mutex                    lock;
        struct vb2_queue                queue;
};

#define notifier_to_isi(n) container_of(n, struct atmel_isi, notifier)

static void isi_writel(struct atmel_isi *isi, u32 reg, u32 val)
{
        writel(val, isi->regs + reg);
}
static u32 isi_readl(struct atmel_isi *isi, u32 reg)
{
        return readl(isi->regs + reg);
}

static void configure_geometry(struct atmel_isi *isi)
{
        u32 cfg2, psize;
        u32 fourcc = isi->current_fmt->fourcc;

        isi->enable_preview_path = fourcc == V4L2_PIX_FMT_RGB565 ||
                                   fourcc == V4L2_PIX_FMT_RGB32 ||
                                   fourcc == V4L2_PIX_FMT_Y16;

        /* According to sensor's output format to set cfg2 */
        cfg2 = isi->current_fmt->swap;

        isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
        /* Set width */
        cfg2 |= ((isi->fmt.fmt.pix.width - 1) << ISI_CFG2_IM_HSIZE_OFFSET) &
                        ISI_CFG2_IM_HSIZE_MASK;
        /* Set height */
        cfg2 |= ((isi->fmt.fmt.pix.height - 1) << ISI_CFG2_IM_VSIZE_OFFSET)
                        & ISI_CFG2_IM_VSIZE_MASK;
        isi_writel(isi, ISI_CFG2, cfg2);

        /* No down sampling, preview size equal to sensor output size */
        psize = ((isi->fmt.fmt.pix.width - 1) << ISI_PSIZE_PREV_HSIZE_OFFSET) &
                ISI_PSIZE_PREV_HSIZE_MASK;
        psize |= ((isi->fmt.fmt.pix.height - 1) << ISI_PSIZE_PREV_VSIZE_OFFSET) &
                ISI_PSIZE_PREV_VSIZE_MASK;
        isi_writel(isi, ISI_PSIZE, psize);
        isi_writel(isi, ISI_PDECF, ISI_PDECF_NO_SAMPLING);
}

static irqreturn_t atmel_isi_handle_streaming(struct atmel_isi *isi)
{
        if (isi->active) {
                struct vb2_v4l2_buffer *vbuf = &isi->active->vb;
                struct frame_buffer *buf = isi->active;

                list_del_init(&buf->list);
                vbuf->vb2_buf.timestamp = ktime_get_ns();
                vbuf->sequence = isi->sequence++;
                vbuf->field = V4L2_FIELD_NONE;
                vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);
        }

        if (list_empty(&isi->video_buffer_list)) {
                isi->active = NULL;
        } else {
                /* start next dma frame. */
                isi->active = list_entry(isi->video_buffer_list.next,
                                        struct frame_buffer, list);
                if (!isi->enable_preview_path) {
                        isi_writel(isi, ISI_DMA_C_DSCR,
                                (u32)isi->active->p_dma_desc->fbd_phys);
                        isi_writel(isi, ISI_DMA_C_CTRL,
                                ISI_DMA_CTRL_FETCH | ISI_DMA_CTRL_DONE);
                        isi_writel(isi, ISI_DMA_CHER, ISI_DMA_CHSR_C_CH);
                } else {
                        isi_writel(isi, ISI_DMA_P_DSCR,
                                (u32)isi->active->p_dma_desc->fbd_phys);
                        isi_writel(isi, ISI_DMA_P_CTRL,
                                ISI_DMA_CTRL_FETCH | ISI_DMA_CTRL_DONE);
                        isi_writel(isi, ISI_DMA_CHER, ISI_DMA_CHSR_P_CH);
                }
        }
        return IRQ_HANDLED;
}

/* ISI interrupt service routine */
static irqreturn_t isi_interrupt(int irq, void *dev_id)
{
        struct atmel_isi *isi = dev_id;
        u32 status, mask, pending;
        irqreturn_t ret = IRQ_NONE;

        spin_lock(&isi->irqlock);

        status = isi_readl(isi, ISI_STATUS);
        mask = isi_readl(isi, ISI_INTMASK);
        pending = status & mask;

        if (pending & ISI_CTRL_SRST) {
                complete(&isi->complete);
                isi_writel(isi, ISI_INTDIS, ISI_CTRL_SRST);
                ret = IRQ_HANDLED;
        } else if (pending & ISI_CTRL_DIS) {
                complete(&isi->complete);
                isi_writel(isi, ISI_INTDIS, ISI_CTRL_DIS);
                ret = IRQ_HANDLED;
        } else {
                if (likely(pending & ISI_SR_CXFR_DONE) ||
                                likely(pending & ISI_SR_PXFR_DONE))
                        ret = atmel_isi_handle_streaming(isi);
        }

        spin_unlock(&isi->irqlock);
        return ret;
}

#define WAIT_ISI_RESET          1
#define WAIT_ISI_DISABLE        0
static int atmel_isi_wait_status(struct atmel_isi *isi, int wait_reset)
{
        unsigned long time_left;
        /*
         * The reset or disable will only succeed if we have a
         * pixel clock from the camera.
         */
        init_completion(&isi->complete);

        if (wait_reset) {
                isi_writel(isi, ISI_INTEN, ISI_CTRL_SRST);
                isi_writel(isi, ISI_CTRL, ISI_CTRL_SRST);
        } else {
                isi_writel(isi, ISI_INTEN, ISI_CTRL_DIS);
                isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
        }

        time_left = wait_for_completion_timeout(&isi->complete,
                                                msecs_to_jiffies(500));
        if (time_left == 0)
                return -ETIMEDOUT;

        return 0;
}

/* ------------------------------------------------------------------
        Videobuf operations
   ------------------------------------------------------------------*/
static int queue_setup(struct vb2_queue *vq,
                                unsigned int *nbuffers, unsigned int *nplanes,
                                unsigned int sizes[], struct device *alloc_devs[])
{
        struct atmel_isi *isi = vb2_get_drv_priv(vq);
        unsigned long size;

        size = isi->fmt.fmt.pix.sizeimage;

        /* Make sure the image size is large enough. */
        if (*nplanes)
                return sizes[0] < size ? -EINVAL : 0;

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

        isi->active = NULL;

        dev_dbg(isi->dev, "%s, count=%d, size=%ld\n", __func__,
                *nbuffers, size);

        return 0;
}

static int buffer_init(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct frame_buffer *buf = container_of(vbuf, struct frame_buffer, vb);

        buf->p_dma_desc = NULL;
        INIT_LIST_HEAD(&buf->list);

        return 0;
}

static int buffer_prepare(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct frame_buffer *buf = container_of(vbuf, struct frame_buffer, vb);
        struct atmel_isi *isi = vb2_get_drv_priv(vb->vb2_queue);
        unsigned long size;
        struct isi_dma_desc *desc;

        size = isi->fmt.fmt.pix.sizeimage;

        if (vb2_plane_size(vb, 0) < size) {
                dev_err(isi->dev, "%s data will not fit into plane (%lu < %lu)\n",
                                __func__, vb2_plane_size(vb, 0), size);
                return -EINVAL;
        }

        vb2_set_plane_payload(vb, 0, size);

        if (!buf->p_dma_desc) {
                if (list_empty(&isi->dma_desc_head)) {
                        dev_err(isi->dev, "Not enough dma descriptors.\n");
                        return -EINVAL;
                } else {
                        /* Get an available descriptor */
                        desc = list_entry(isi->dma_desc_head.next,
                                                struct isi_dma_desc, list);
                        /* Delete the descriptor since now it is used */
                        list_del_init(&desc->list);

                        /* Initialize the dma descriptor */
                        desc->p_fbd->fb_address =
                                        vb2_dma_contig_plane_dma_addr(vb, 0);
                        desc->p_fbd->next_fbd_address = 0;
                        set_dma_ctrl(desc->p_fbd, ISI_DMA_CTRL_WB);

                        buf->p_dma_desc = desc;
                }
        }
        return 0;
}

static void buffer_cleanup(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct atmel_isi *isi = vb2_get_drv_priv(vb->vb2_queue);
        struct frame_buffer *buf = container_of(vbuf, struct frame_buffer, vb);

        /* This descriptor is available now and we add to head list */
        if (buf->p_dma_desc)
                list_add(&buf->p_dma_desc->list, &isi->dma_desc_head);
}

static void start_dma(struct atmel_isi *isi, struct frame_buffer *buffer)
{
        u32 ctrl, cfg1;

        cfg1 = isi_readl(isi, ISI_CFG1);
        /* Enable irq: cxfr for the codec path, pxfr for the preview path */
        isi_writel(isi, ISI_INTEN,
                        ISI_SR_CXFR_DONE | ISI_SR_PXFR_DONE);

        /* Check if already in a frame */
        if (!isi->enable_preview_path) {
                if (isi_readl(isi, ISI_STATUS) & ISI_CTRL_CDC) {
                        dev_err(isi->dev, "Already in frame handling.\n");
                        return;
                }

                isi_writel(isi, ISI_DMA_C_DSCR,
                                (u32)buffer->p_dma_desc->fbd_phys);
                isi_writel(isi, ISI_DMA_C_CTRL,
                                ISI_DMA_CTRL_FETCH | ISI_DMA_CTRL_DONE);
                isi_writel(isi, ISI_DMA_CHER, ISI_DMA_CHSR_C_CH);
        } else {
                isi_writel(isi, ISI_DMA_P_DSCR,
                                (u32)buffer->p_dma_desc->fbd_phys);
                isi_writel(isi, ISI_DMA_P_CTRL,
                                ISI_DMA_CTRL_FETCH | ISI_DMA_CTRL_DONE);
                isi_writel(isi, ISI_DMA_CHER, ISI_DMA_CHSR_P_CH);
        }

        cfg1 &= ~ISI_CFG1_FRATE_DIV_MASK;
        /* Enable linked list */
        cfg1 |= isi->pdata.frate | ISI_CFG1_DISCR;

        /* Enable ISI */
        ctrl = ISI_CTRL_EN;

        if (!isi->enable_preview_path)
                ctrl |= ISI_CTRL_CDC;

        isi_writel(isi, ISI_CTRL, ctrl);
        isi_writel(isi, ISI_CFG1, cfg1);
}

static void buffer_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct atmel_isi *isi = vb2_get_drv_priv(vb->vb2_queue);
        struct frame_buffer *buf = container_of(vbuf, struct frame_buffer, vb);
        unsigned long flags = 0;

        spin_lock_irqsave(&isi->irqlock, flags);
        list_add_tail(&buf->list, &isi->video_buffer_list);

        if (!isi->active) {
                isi->active = buf;
                if (vb2_is_streaming(vb->vb2_queue))
                        start_dma(isi, buf);
        }
        spin_unlock_irqrestore(&isi->irqlock, flags);
}

static int start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct atmel_isi *isi = vb2_get_drv_priv(vq);
        struct frame_buffer *buf, *node;
        int ret;

        ret = pm_runtime_resume_and_get(isi->dev);
        if (ret < 0)
                return ret;

        /* Enable stream on the sub device */
        ret = v4l2_subdev_call(isi->entity.subdev, video, s_stream, 1);
        if (ret && ret != -ENOIOCTLCMD) {
                dev_err(isi->dev, "stream on failed in subdev\n");
                goto err_start_stream;
        }

        /* Reset ISI */
        ret = atmel_isi_wait_status(isi, WAIT_ISI_RESET);
        if (ret < 0) {
                dev_err(isi->dev, "Reset ISI timed out\n");
                goto err_reset;
        }
        /* Disable all interrupts */
        isi_writel(isi, ISI_INTDIS, (u32)~0UL);

        isi->sequence = 0;
        configure_geometry(isi);

        spin_lock_irq(&isi->irqlock);
        /* Clear any pending interrupt */
        isi_readl(isi, ISI_STATUS);

        start_dma(isi, isi->active);
        spin_unlock_irq(&isi->irqlock);

        return 0;

err_reset:
        v4l2_subdev_call(isi->entity.subdev, video, s_stream, 0);

err_start_stream:
        pm_runtime_put(isi->dev);

        spin_lock_irq(&isi->irqlock);
        isi->active = NULL;
        /* Release all active buffers */
        list_for_each_entry_safe(buf, node, &isi->video_buffer_list, list) {
                list_del_init(&buf->list);
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
        }
        spin_unlock_irq(&isi->irqlock);

        return ret;
}

/* abort streaming and wait for last buffer */
static void stop_streaming(struct vb2_queue *vq)
{
        struct atmel_isi *isi = vb2_get_drv_priv(vq);
        struct frame_buffer *buf, *node;
        int ret = 0;
        unsigned long timeout;

        /* Disable stream on the sub device */
        ret = v4l2_subdev_call(isi->entity.subdev, video, s_stream, 0);
        if (ret && ret != -ENOIOCTLCMD)
                dev_err(isi->dev, "stream off failed in subdev\n");

        spin_lock_irq(&isi->irqlock);
        isi->active = NULL;
        /* Release all active buffers */
        list_for_each_entry_safe(buf, node, &isi->video_buffer_list, list) {
                list_del_init(&buf->list);
                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
        }
        spin_unlock_irq(&isi->irqlock);

        if (!isi->enable_preview_path) {
                timeout = jiffies + (FRAME_INTERVAL_MILLI_SEC * HZ) / 1000;
                /* Wait until the end of the current frame. */
                while ((isi_readl(isi, ISI_STATUS) & ISI_CTRL_CDC) &&
                                time_before(jiffies, timeout))
                        msleep(1);

                if (time_after(jiffies, timeout))
                        dev_err(isi->dev,
                                "Timeout waiting for finishing codec request\n");
        }

        /* Disable interrupts */
        isi_writel(isi, ISI_INTDIS,
                        ISI_SR_CXFR_DONE | ISI_SR_PXFR_DONE);

        /* Disable ISI and wait for it is done */
        ret = atmel_isi_wait_status(isi, WAIT_ISI_DISABLE);
        if (ret < 0)
                dev_err(isi->dev, "Disable ISI timed out\n");

        pm_runtime_put(isi->dev);
}

static const struct vb2_ops isi_video_qops = {
        .queue_setup            = queue_setup,
        .buf_init               = buffer_init,
        .buf_prepare            = buffer_prepare,
        .buf_cleanup            = buffer_cleanup,
        .buf_queue              = buffer_queue,
        .start_streaming        = start_streaming,
        .stop_streaming         = stop_streaming,
};

static int isi_g_fmt_vid_cap(struct file *file, void *priv,
                              struct v4l2_format *fmt)
{
        struct atmel_isi *isi = video_drvdata(file);

        *fmt = isi->fmt;

        return 0;
}

static const struct isi_format *find_format_by_fourcc(struct atmel_isi *isi,
                                                      unsigned int fourcc)
{
        unsigned int num_formats = isi->num_user_formats;
        const struct isi_format *fmt;
        unsigned int i;

        for (i = 0; i < num_formats; i++) {
                fmt = isi->user_formats[i];
                if (fmt->fourcc == fourcc)
                        return fmt;
        }

        return NULL;
}

static void isi_try_fse(struct atmel_isi *isi, const struct isi_format *isi_fmt,
                        struct v4l2_subdev_state *sd_state)
{
        struct v4l2_rect *try_crop =
                v4l2_subdev_state_get_crop(sd_state, 0);
        struct v4l2_subdev_frame_size_enum fse = {
                .code = isi_fmt->mbus_code,
                .which = V4L2_SUBDEV_FORMAT_TRY,
        };
        int ret;

        ret = v4l2_subdev_call(isi->entity.subdev, pad, enum_frame_size,
                               sd_state, &fse);
        /*
         * Attempt to obtain format size from subdev. If not available,
         * just use the maximum ISI can receive.
         */
        if (ret) {
                try_crop->width = MAX_SUPPORT_WIDTH;
                try_crop->height = MAX_SUPPORT_HEIGHT;
        } else {
                try_crop->width = fse.max_width;
                try_crop->height = fse.max_height;
        }
}

static int isi_try_fmt(struct atmel_isi *isi, struct v4l2_format *f,
                       const struct isi_format **current_fmt)
{
        const struct isi_format *isi_fmt;
        struct v4l2_pix_format *pixfmt = &f->fmt.pix;
        struct v4l2_subdev_pad_config pad_cfg = {};
        struct v4l2_subdev_state pad_state = {
                .sd = isi->entity.subdev,
                .pads = &pad_cfg,
        };
        struct v4l2_subdev_format format = {
                .which = V4L2_SUBDEV_FORMAT_TRY,
        };
        int ret;

        isi_fmt = find_format_by_fourcc(isi, pixfmt->pixelformat);
        if (!isi_fmt) {
                isi_fmt = isi->user_formats[isi->num_user_formats - 1];
                pixfmt->pixelformat = isi_fmt->fourcc;
        }

        /* Limit to Atmel ISI hardware capabilities */
        pixfmt->width = clamp(pixfmt->width, 0U, MAX_SUPPORT_WIDTH);
        pixfmt->height = clamp(pixfmt->height, 0U, MAX_SUPPORT_HEIGHT);

        v4l2_fill_mbus_format(&format.format, pixfmt, isi_fmt->mbus_code);

        isi_try_fse(isi, isi_fmt, &pad_state);

        ret = v4l2_subdev_call(isi->entity.subdev, pad, set_fmt,
                               &pad_state, &format);
        if (ret < 0)
                return ret;

        v4l2_fill_pix_format(pixfmt, &format.format);

        pixfmt->field = V4L2_FIELD_NONE;
        pixfmt->bytesperline = pixfmt->width * isi_fmt->bpp;
        pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;

        if (current_fmt)
                *current_fmt = isi_fmt;

        return 0;
}

static int isi_set_fmt(struct atmel_isi *isi, struct v4l2_format *f)
{
        struct v4l2_subdev_format format = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        const struct isi_format *current_fmt;
        int ret;

        ret = isi_try_fmt(isi, f, &current_fmt);
        if (ret)
                return ret;

        v4l2_fill_mbus_format(&format.format, &f->fmt.pix,
                              current_fmt->mbus_code);
        ret = v4l2_subdev_call(isi->entity.subdev, pad,
                               set_fmt, NULL, &format);
        if (ret < 0)
                return ret;

        isi->fmt = *f;
        isi->current_fmt = current_fmt;

        return 0;
}

static int isi_s_fmt_vid_cap(struct file *file, void *priv,
                              struct v4l2_format *f)
{
        struct atmel_isi *isi = video_drvdata(file);

        if (vb2_is_streaming(&isi->queue))
                return -EBUSY;

        return isi_set_fmt(isi, f);
}

static int isi_try_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        struct atmel_isi *isi = video_drvdata(file);

        return isi_try_fmt(isi, f, NULL);
}

static int isi_enum_fmt_vid_cap(struct file *file, void  *priv,
                                struct v4l2_fmtdesc *f)
{
        struct atmel_isi *isi = video_drvdata(file);

        if (f->index >= isi->num_user_formats)
                return -EINVAL;

        f->pixelformat = isi->user_formats[f->index]->fourcc;
        return 0;
}

static int isi_querycap(struct file *file, void *priv,
                        struct v4l2_capability *cap)
{
        strscpy(cap->driver, "atmel-isi", sizeof(cap->driver));
        strscpy(cap->card, "Atmel Image Sensor Interface", sizeof(cap->card));
        strscpy(cap->bus_info, "platform:isi", sizeof(cap->bus_info));
        return 0;
}

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

        i->type = V4L2_INPUT_TYPE_CAMERA;
        strscpy(i->name, "Camera", sizeof(i->name));
        return 0;
}

static int isi_g_input(struct file *file, void *priv, unsigned int *i)
{
        *i = 0;
        return 0;
}

static int isi_s_input(struct file *file, void *priv, unsigned int i)
{
        if (i > 0)
                return -EINVAL;
        return 0;
}

static int isi_g_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
{
        struct atmel_isi *isi = video_drvdata(file);

        return v4l2_g_parm_cap(video_devdata(file), isi->entity.subdev, a);
}

static int isi_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
{
        struct atmel_isi *isi = video_drvdata(file);

        return v4l2_s_parm_cap(video_devdata(file), isi->entity.subdev, a);
}

static int isi_enum_framesizes(struct file *file, void *fh,
                               struct v4l2_frmsizeenum *fsize)
{
        struct atmel_isi *isi = video_drvdata(file);
        const struct isi_format *isi_fmt;
        struct v4l2_subdev_frame_size_enum fse = {
                .index = fsize->index,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        int ret;

        isi_fmt = find_format_by_fourcc(isi, fsize->pixel_format);
        if (!isi_fmt)
                return -EINVAL;

        fse.code = isi_fmt->mbus_code;

        ret = v4l2_subdev_call(isi->entity.subdev, pad, enum_frame_size,
                               NULL, &fse);
        if (ret)
                return ret;

        fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
        fsize->discrete.width = fse.max_width;
        fsize->discrete.height = fse.max_height;

        return 0;
}

static int isi_enum_frameintervals(struct file *file, void *fh,
                                    struct v4l2_frmivalenum *fival)
{
        struct atmel_isi *isi = video_drvdata(file);
        const struct isi_format *isi_fmt;
        struct v4l2_subdev_frame_interval_enum fie = {
                .index = fival->index,
                .width = fival->width,
                .height = fival->height,
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        int ret;

        isi_fmt = find_format_by_fourcc(isi, fival->pixel_format);
        if (!isi_fmt)
                return -EINVAL;

        fie.code = isi_fmt->mbus_code;

        ret = v4l2_subdev_call(isi->entity.subdev, pad,
                               enum_frame_interval, NULL, &fie);
        if (ret)
                return ret;

        fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
        fival->discrete = fie.interval;

        return 0;
}

static int isi_camera_set_bus_param(struct atmel_isi *isi)
{
        u32 cfg1 = 0;
        int ret;

        /* set bus param for ISI */
        if (isi->pdata.hsync_act_low)
                cfg1 |= ISI_CFG1_HSYNC_POL_ACTIVE_LOW;
        if (isi->pdata.vsync_act_low)
                cfg1 |= ISI_CFG1_VSYNC_POL_ACTIVE_LOW;
        if (isi->pdata.pclk_act_falling)
                cfg1 |= ISI_CFG1_PIXCLK_POL_ACTIVE_FALLING;
        if (isi->pdata.has_emb_sync)
                cfg1 |= ISI_CFG1_EMB_SYNC;
        if (isi->pdata.full_mode)
                cfg1 |= ISI_CFG1_FULL_MODE;

        cfg1 |= ISI_CFG1_THMASK_BEATS_16;

        /* Enable PM and peripheral clock before operate isi registers */
        ret = pm_runtime_resume_and_get(isi->dev);
        if (ret < 0)
                return ret;

        isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
        isi_writel(isi, ISI_CFG1, cfg1);

        pm_runtime_put(isi->dev);

        return 0;
}

/* -----------------------------------------------------------------------*/
static int atmel_isi_parse_dt(struct atmel_isi *isi,
                        struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct v4l2_fwnode_endpoint ep = { .bus_type = 0 };
        int err;

        /* Default settings for ISI */
        isi->pdata.full_mode = 1;
        isi->pdata.frate = ISI_CFG1_FRATE_CAPTURE_ALL;

        np = of_graph_get_endpoint_by_regs(np, 0, -1);
        if (!np) {
                dev_err(&pdev->dev, "Could not find the endpoint\n");
                return -EINVAL;
        }

        err = v4l2_fwnode_endpoint_parse(of_fwnode_handle(np), &ep);
        of_node_put(np);
        if (err) {
                dev_err(&pdev->dev, "Could not parse the endpoint\n");
                return err;
        }

        switch (ep.bus.parallel.bus_width) {
        case 8:
                isi->pdata.data_width_flags = ISI_DATAWIDTH_8;
                break;
        case 10:
                isi->pdata.data_width_flags =
                                ISI_DATAWIDTH_8 | ISI_DATAWIDTH_10;
                break;
        default:
                dev_err(&pdev->dev, "Unsupported bus width: %d\n",
                                ep.bus.parallel.bus_width);
                return -EINVAL;
        }

        if (ep.bus.parallel.flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)
                isi->pdata.hsync_act_low = true;
        if (ep.bus.parallel.flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
                isi->pdata.vsync_act_low = true;
        if (ep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
                isi->pdata.pclk_act_falling = true;

        if (ep.bus_type == V4L2_MBUS_BT656)
                isi->pdata.has_emb_sync = true;

        return 0;
}

static int isi_open(struct file *file)
{
        struct atmel_isi *isi = video_drvdata(file);
        struct v4l2_subdev *sd = isi->entity.subdev;
        int ret;

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

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

        if (!v4l2_fh_is_singular_file(file))
                goto fh_rel;

        ret = v4l2_subdev_call(sd, core, s_power, 1);
        if (ret < 0 && ret != -ENOIOCTLCMD)
                goto fh_rel;

        ret = isi_set_fmt(isi, &isi->fmt);
        if (ret)
                v4l2_subdev_call(sd, core, s_power, 0);
fh_rel:
        if (ret)
                v4l2_fh_release(file);
unlock:
        mutex_unlock(&isi->lock);
        return ret;
}

static int isi_release(struct file *file)
{
        struct atmel_isi *isi = video_drvdata(file);
        struct v4l2_subdev *sd = isi->entity.subdev;
        bool fh_singular;
        int ret;

        mutex_lock(&isi->lock);

        fh_singular = v4l2_fh_is_singular_file(file);

        ret = _vb2_fop_release(file, NULL);

        if (fh_singular)
                v4l2_subdev_call(sd, core, s_power, 0);

        mutex_unlock(&isi->lock);

        return ret;
}

static const struct v4l2_ioctl_ops isi_ioctl_ops = {
        .vidioc_querycap                = isi_querycap,

        .vidioc_try_fmt_vid_cap         = isi_try_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap           = isi_g_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap           = isi_s_fmt_vid_cap,
        .vidioc_enum_fmt_vid_cap        = isi_enum_fmt_vid_cap,

        .vidioc_enum_input              = isi_enum_input,
        .vidioc_g_input                 = isi_g_input,
        .vidioc_s_input                 = isi_s_input,

        .vidioc_g_parm                  = isi_g_parm,
        .vidioc_s_parm                  = isi_s_parm,
        .vidioc_enum_framesizes         = isi_enum_framesizes,
        .vidioc_enum_frameintervals     = isi_enum_frameintervals,

        .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_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,

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

static const struct v4l2_file_operations isi_fops = {
        .owner          = THIS_MODULE,
        .unlocked_ioctl = video_ioctl2,
        .open           = isi_open,
        .release        = isi_release,
        .poll           = vb2_fop_poll,
        .mmap           = vb2_fop_mmap,
        .read           = vb2_fop_read,
};

static int isi_set_default_fmt(struct atmel_isi *isi)
{
        struct v4l2_format f = {
                .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
                .fmt.pix = {
                        .width          = VGA_WIDTH,
                        .height         = VGA_HEIGHT,
                        .field          = V4L2_FIELD_NONE,
                        .pixelformat    = isi->user_formats[0]->fourcc,
                },
        };
        int ret;

        ret = isi_try_fmt(isi, &f, NULL);
        if (ret)
                return ret;
        isi->current_fmt = isi->user_formats[0];
        isi->fmt = f;
        return 0;
}

static const struct isi_format isi_formats[] = {
        {
                .fourcc = V4L2_PIX_FMT_YUYV,
                .mbus_code = MEDIA_BUS_FMT_YUYV8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_DEFAULT,
        }, {
                .fourcc = V4L2_PIX_FMT_YUYV,
                .mbus_code = MEDIA_BUS_FMT_YVYU8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_MODE_1,
        }, {
                .fourcc = V4L2_PIX_FMT_YUYV,
                .mbus_code = MEDIA_BUS_FMT_UYVY8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_MODE_2,
        }, {
                .fourcc = V4L2_PIX_FMT_YUYV,
                .mbus_code = MEDIA_BUS_FMT_VYUY8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_MODE_3,
        }, {
                .fourcc = V4L2_PIX_FMT_RGB565,
                .mbus_code = MEDIA_BUS_FMT_YUYV8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_MODE_2,
        }, {
                .fourcc = V4L2_PIX_FMT_RGB565,
                .mbus_code = MEDIA_BUS_FMT_YVYU8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_MODE_3,
        }, {
                .fourcc = V4L2_PIX_FMT_RGB565,
                .mbus_code = MEDIA_BUS_FMT_UYVY8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_DEFAULT,
        }, {
                .fourcc = V4L2_PIX_FMT_RGB565,
                .mbus_code = MEDIA_BUS_FMT_VYUY8_2X8,
                .bpp = 2,
                .swap = ISI_CFG2_YCC_SWAP_MODE_1,
        }, {
                .fourcc = V4L2_PIX_FMT_GREY,
                .mbus_code = MEDIA_BUS_FMT_Y10_1X10,
                .bpp = 1,
                .swap = ISI_CFG2_GS_MODE_2_PIXEL | ISI_CFG2_GRAYSCALE,
        }, {
                .fourcc = V4L2_PIX_FMT_Y16,
                .mbus_code = MEDIA_BUS_FMT_Y10_1X10,
                .bpp = 2,
                .swap = ISI_CFG2_GS_MODE_2_PIXEL | ISI_CFG2_GRAYSCALE,
        },
};

static int isi_formats_init(struct atmel_isi *isi)
{
        const struct isi_format *isi_fmts[ARRAY_SIZE(isi_formats)];
        unsigned int num_fmts = 0, i, j;
        struct v4l2_subdev *subdev = isi->entity.subdev;
        struct v4l2_subdev_mbus_code_enum mbus_code = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };

        while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
                                 NULL, &mbus_code)) {
                for (i = 0; i < ARRAY_SIZE(isi_formats); i++) {
                        if (isi_formats[i].mbus_code != mbus_code.code)
                                continue;

                        /* Code supported, have we got this fourcc yet? */
                        for (j = 0; j < num_fmts; j++)
                                if (isi_fmts[j]->fourcc == isi_formats[i].fourcc)
                                        /* Already available */
                                        break;
                        if (j == num_fmts)
                                /* new */
                                isi_fmts[num_fmts++] = isi_formats + i;
                }
                mbus_code.index++;
        }

        if (!num_fmts)
                return -ENXIO;

        isi->num_user_formats = num_fmts;
        isi->user_formats = devm_kmemdup_array(isi->dev, isi_fmts, num_fmts,
                                               sizeof(*isi_fmts), GFP_KERNEL);
        if (!isi->user_formats)
                return -ENOMEM;

        isi->current_fmt = isi->user_formats[0];
        return 0;
}

static int isi_graph_notify_complete(struct v4l2_async_notifier *notifier)
{
        struct atmel_isi *isi = notifier_to_isi(notifier);
        int ret;

        isi->vdev->ctrl_handler = isi->entity.subdev->ctrl_handler;
        ret = isi_formats_init(isi);
        if (ret) {
                dev_err(isi->dev, "No supported mediabus format found\n");
                return ret;
        }
        ret = isi_camera_set_bus_param(isi);
        if (ret) {
                dev_err(isi->dev, "Can't wake up device\n");
                return ret;
        }

        ret = isi_set_default_fmt(isi);
        if (ret) {
                dev_err(isi->dev, "Could not set default format\n");
                return ret;
        }

        ret = video_register_device(isi->vdev, VFL_TYPE_VIDEO, -1);
        if (ret) {
                dev_err(isi->dev, "Failed to register video device\n");
                return ret;
        }

        dev_dbg(isi->dev, "Device registered as %s\n",
                video_device_node_name(isi->vdev));
        return 0;
}

static void isi_graph_notify_unbind(struct v4l2_async_notifier *notifier,
                                     struct v4l2_subdev *sd,
                                     struct v4l2_async_connection *asd)
{
        struct atmel_isi *isi = notifier_to_isi(notifier);

        dev_dbg(isi->dev, "Removing %s\n", video_device_node_name(isi->vdev));

        /* Checks internally if vdev have been init or not */
        video_unregister_device(isi->vdev);
}

static int isi_graph_notify_bound(struct v4l2_async_notifier *notifier,
                                   struct v4l2_subdev *subdev,
                                   struct v4l2_async_connection *asd)
{
        struct atmel_isi *isi = notifier_to_isi(notifier);

        dev_dbg(isi->dev, "subdev %s bound\n", subdev->name);

        isi->entity.subdev = subdev;

        return 0;
}

static const struct v4l2_async_notifier_operations isi_graph_notify_ops = {
        .bound = isi_graph_notify_bound,
        .unbind = isi_graph_notify_unbind,
        .complete = isi_graph_notify_complete,
};

static int isi_graph_init(struct atmel_isi *isi)
{
        struct v4l2_async_connection *asd;
        struct device_node *ep;
        int ret;

        ep = of_graph_get_endpoint_by_regs(isi->dev->of_node, 0, -1);
        if (!ep)
                return -EINVAL;

        v4l2_async_nf_init(&isi->notifier, &isi->v4l2_dev);

        asd = v4l2_async_nf_add_fwnode_remote(&isi->notifier,
                                              of_fwnode_handle(ep),
                                              struct v4l2_async_connection);
        of_node_put(ep);

        if (IS_ERR(asd))
                return PTR_ERR(asd);

        isi->notifier.ops = &isi_graph_notify_ops;

        ret = v4l2_async_nf_register(&isi->notifier);
        if (ret < 0) {
                dev_err(isi->dev, "Notifier registration failed\n");
                v4l2_async_nf_cleanup(&isi->notifier);
                return ret;
        }

        return 0;
}


static int atmel_isi_probe(struct platform_device *pdev)
{
        int irq;
        struct atmel_isi *isi;
        struct vb2_queue *q;
        int ret, i;

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

        isi->pclk = devm_clk_get(&pdev->dev, "isi_clk");
        if (IS_ERR(isi->pclk))
                return PTR_ERR(isi->pclk);

        ret = atmel_isi_parse_dt(isi, pdev);
        if (ret)
                return ret;

        isi->active = NULL;
        isi->dev = &pdev->dev;
        mutex_init(&isi->lock);
        spin_lock_init(&isi->irqlock);
        INIT_LIST_HEAD(&isi->video_buffer_list);
        INIT_LIST_HEAD(&isi->dma_desc_head);

        q = &isi->queue;

        /* Initialize the top-level structure */
        ret = v4l2_device_register(&pdev->dev, &isi->v4l2_dev);
        if (ret)
                return ret;

        isi->vdev = video_device_alloc();
        if (!isi->vdev) {
                ret = -ENOMEM;
                goto err_vdev_alloc;
        }

        /* video node */
        isi->vdev->fops = &isi_fops;
        isi->vdev->v4l2_dev = &isi->v4l2_dev;
        isi->vdev->queue = &isi->queue;
        strscpy(isi->vdev->name, KBUILD_MODNAME, sizeof(isi->vdev->name));
        isi->vdev->release = video_device_release;
        isi->vdev->ioctl_ops = &isi_ioctl_ops;
        isi->vdev->lock = &isi->lock;
        isi->vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
                V4L2_CAP_READWRITE;
        video_set_drvdata(isi->vdev, isi);

        /* buffer queue */
        q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        q->io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF;
        q->lock = &isi->lock;
        q->drv_priv = isi;
        q->buf_struct_size = sizeof(struct frame_buffer);
        q->ops = &isi_video_qops;
        q->mem_ops = &vb2_dma_contig_memops;
        q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        q->min_queued_buffers = 2;
        q->dev = &pdev->dev;

        ret = vb2_queue_init(q);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to initialize VB2 queue\n");
                goto err_vb2_queue;
        }
        isi->p_fb_descriptors = dma_alloc_coherent(&pdev->dev,
                                sizeof(struct fbd) * VIDEO_MAX_FRAME,
                                &isi->fb_descriptors_phys,
                                GFP_KERNEL);
        if (!isi->p_fb_descriptors) {
                dev_err(&pdev->dev, "Can't allocate descriptors!\n");
                ret = -ENOMEM;
                goto err_dma_alloc;
        }

        for (i = 0; i < VIDEO_MAX_FRAME; i++) {
                isi->dma_desc[i].p_fbd = isi->p_fb_descriptors + i;
                isi->dma_desc[i].fbd_phys = isi->fb_descriptors_phys +
                                        i * sizeof(struct fbd);
                list_add(&isi->dma_desc[i].list, &isi->dma_desc_head);
        }

        isi->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(isi->regs)) {
                ret = PTR_ERR(isi->regs);
                goto err_ioremap;
        }

        if (isi->pdata.data_width_flags & ISI_DATAWIDTH_8)
                isi->width_flags = 1 << 7;
        if (isi->pdata.data_width_flags & ISI_DATAWIDTH_10)
                isi->width_flags |= 1 << 9;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                ret = irq;
                goto err_req_irq;
        }

        ret = devm_request_irq(&pdev->dev, irq, isi_interrupt, 0, "isi", isi);
        if (ret) {
                dev_err(&pdev->dev, "Unable to request irq %d\n", irq);
                goto err_req_irq;
        }
        isi->irq = irq;

        ret = isi_graph_init(isi);
        if (ret < 0)
                goto err_req_irq;

        pm_suspend_ignore_children(&pdev->dev, true);
        pm_runtime_enable(&pdev->dev);
        platform_set_drvdata(pdev, isi);
        return 0;

err_req_irq:
err_ioremap:
        dma_free_coherent(&pdev->dev,
                        sizeof(struct fbd) * VIDEO_MAX_FRAME,
                        isi->p_fb_descriptors,
                        isi->fb_descriptors_phys);
err_dma_alloc:
err_vb2_queue:
        video_device_release(isi->vdev);
err_vdev_alloc:
        v4l2_device_unregister(&isi->v4l2_dev);

        return ret;
}

static void atmel_isi_remove(struct platform_device *pdev)
{
        struct atmel_isi *isi = platform_get_drvdata(pdev);

        dma_free_coherent(&pdev->dev,
                        sizeof(struct fbd) * VIDEO_MAX_FRAME,
                        isi->p_fb_descriptors,
                        isi->fb_descriptors_phys);
        pm_runtime_disable(&pdev->dev);
        v4l2_async_nf_unregister(&isi->notifier);
        v4l2_async_nf_cleanup(&isi->notifier);
        v4l2_device_unregister(&isi->v4l2_dev);
}

#ifdef CONFIG_PM
static int atmel_isi_runtime_suspend(struct device *dev)
{
        struct atmel_isi *isi = dev_get_drvdata(dev);

        clk_disable_unprepare(isi->pclk);

        return 0;
}
static int atmel_isi_runtime_resume(struct device *dev)
{
        struct atmel_isi *isi = dev_get_drvdata(dev);

        return clk_prepare_enable(isi->pclk);
}
#endif /* CONFIG_PM */

static const struct dev_pm_ops atmel_isi_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(atmel_isi_runtime_suspend,
                                atmel_isi_runtime_resume, NULL)
};

static const struct of_device_id atmel_isi_of_match[] = {
        { .compatible = "atmel,at91sam9g45-isi" },
        { }
};
MODULE_DEVICE_TABLE(of, atmel_isi_of_match);

static struct platform_driver atmel_isi_driver = {
        .driver         = {
                .name = "atmel_isi",
                .of_match_table = of_match_ptr(atmel_isi_of_match),
                .pm     = &atmel_isi_dev_pm_ops,
        },
        .probe          = atmel_isi_probe,
        .remove         = atmel_isi_remove,
};

module_platform_driver(atmel_isi_driver);

MODULE_AUTHOR("Josh Wu <josh.wu@atmel.com>");
MODULE_DESCRIPTION("The V4L2 driver for Atmel Linux");
MODULE_LICENSE("GPL");