atmel-isi.c

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/*
 * Copyright (c) 2011 Atmel Corporation
 * Josh Wu, <[email protected]>
 *
 * Based on previous work by Lars Haring, <[email protected]>
 * and Sedji Gaouaou
 * Based on the bttv driver for Bt848 with respective copyright holders
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#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/platform_device.h>
#include <linux/slab.h>

#include <media/atmel-isi.h>
#include <media/soc_camera.h>
#include <media/soc_mediabus.h>
#include <media/videobuf2-dma-contig.h>

#define MAX_BUFFER_NUM          32
#define MAX_SUPPORT_WIDTH       2048
#define MAX_SUPPORT_HEIGHT      2048
#define VID_LIMIT_BYTES         (16 * 1024 * 1024)
#define MIN_FRAME_RATE          15
#define FRAME_INTERVAL_MILLI_SEC    (1000 / MIN_FRAME_RATE)

/* ISI states */
enum {
    ISI_STATE_IDLE = 0,
    ISI_STATE_READY,
    ISI_STATE_WAIT_SOF,
};

/* 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;
    u32 fbd_phys;
};

/* Frame buffer data */
struct frame_buffer {
    struct vb2_buffer vb;
    struct isi_dma_desc *p_dma_desc;
    struct list_head list;
};

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

    int             sequence;
    /* State of the ISI module in capturing mode */
    int             state;

    /* Wait queue for waiting for SOF */
    wait_queue_head_t       vsync_wq;

    struct vb2_alloc_ctx        *alloc_ctx;

    /* Allocate descriptors for dma buffer use */
    struct fbd          *p_fb_descriptors;
    u32             fb_descriptors_phys;
    struct              list_head dma_desc_head;
    struct isi_dma_desc     dma_desc[MAX_BUFFER_NUM];

    struct completion       complete;
    /* ISI peripherial clock */
    struct clk          *pclk;
    /* ISI_MCK, feed to camera sensor to generate pixel clock */
    struct clk          *mck;
    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 soc_camera_device    *icd;
    struct soc_camera_host      soc_host;
};

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 int configure_geometry(struct atmel_isi *isi, u32 width,
            u32 height, enum v4l2_mbus_pixelcode code)
{
    u32 cfg2, cr;

    switch (code) {
    /* YUV, including grey */
    case V4L2_MBUS_FMT_Y8_1X8:
        cr = ISI_CFG2_GRAYSCALE;
        break;
    case V4L2_MBUS_FMT_UYVY8_2X8:
        cr = ISI_CFG2_YCC_SWAP_MODE_3;
        break;
    case V4L2_MBUS_FMT_VYUY8_2X8:
        cr = ISI_CFG2_YCC_SWAP_MODE_2;
        break;
    case V4L2_MBUS_FMT_YUYV8_2X8:
        cr = ISI_CFG2_YCC_SWAP_MODE_1;
        break;
    case V4L2_MBUS_FMT_YVYU8_2X8:
        cr = ISI_CFG2_YCC_SWAP_DEFAULT;
        break;
    /* RGB, TODO */
    default:
        return -EINVAL;
    }

    isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);

    cfg2 = isi_readl(isi, ISI_CFG2);
    cfg2 |= cr;
    /* Set width */
    cfg2 &= ~(ISI_CFG2_IM_HSIZE_MASK);
    cfg2 |= ((width - 1) << ISI_CFG2_IM_HSIZE_OFFSET) &
            ISI_CFG2_IM_HSIZE_MASK;
    /* Set height */
    cfg2 &= ~(ISI_CFG2_IM_VSIZE_MASK);
    cfg2 |= ((height - 1) << ISI_CFG2_IM_VSIZE_OFFSET)
            & ISI_CFG2_IM_VSIZE_MASK;
    isi_writel(isi, ISI_CFG2, cfg2);

    return 0;
}

static irqreturn_t atmel_isi_handle_streaming(struct atmel_isi *isi)
{
    if (isi->active) {
        struct vb2_buffer *vb = &isi->active->vb;
        struct frame_buffer *buf = isi->active;

        list_del_init(&buf->list);
        do_gettimeofday(&vb->v4l2_buf.timestamp);
        vb->v4l2_buf.sequence = isi->sequence++;
        vb2_buffer_done(vb, 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);
        isi_writel(isi, ISI_DMA_C_DSCR,
            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);
    }
    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->lock);

    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 ((pending & ISI_SR_VSYNC) &&
                (isi->state == ISI_STATE_IDLE)) {
            isi->state = ISI_STATE_READY;
            wake_up_interruptible(&isi->vsync_wq);
            ret = IRQ_HANDLED;
        }
        if (likely(pending & ISI_SR_CXFR_DONE))
            ret = atmel_isi_handle_streaming(isi);
    }

    spin_unlock(&isi->lock);
    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 timeout;
    /*
     * 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);
    }

    timeout = wait_for_completion_timeout(&isi->complete,
            msecs_to_jiffies(100));
    if (timeout == 0)
        return -ETIMEDOUT;

    return 0;
}

/* ------------------------------------------------------------------
    Videobuf operations
   ------------------------------------------------------------------*/
static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
                unsigned int *nbuffers, unsigned int *nplanes,
                unsigned int sizes[], void *alloc_ctxs[])
{
    struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    unsigned long size;
    int ret;

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

    size = icd->sizeimage;

    if (!*nbuffers || *nbuffers > MAX_BUFFER_NUM)
        *nbuffers = MAX_BUFFER_NUM;

    if (size * *nbuffers > VID_LIMIT_BYTES)
        *nbuffers = VID_LIMIT_BYTES / size;

    *nplanes = 1;
    sizes[0] = size;
    alloc_ctxs[0] = isi->alloc_ctx;

    isi->sequence = 0;
    isi->active = NULL;

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

    return 0;
}

static int buffer_init(struct vb2_buffer *vb)
{
    struct frame_buffer *buf = container_of(vb, 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 soc_camera_device *icd = soc_camera_from_vb2q(vb->vb2_queue);
    struct frame_buffer *buf = container_of(vb, struct frame_buffer, vb);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    unsigned long size;
    struct isi_dma_desc *desc;

    size = icd->sizeimage;

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

    vb2_set_plane_payload(&buf->vb, 0, size);

    if (!buf->p_dma_desc) {
        if (list_empty(&isi->dma_desc_head)) {
            dev_err(icd->parent, "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 soc_camera_device *icd = soc_camera_from_vb2q(vb->vb2_queue);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    struct frame_buffer *buf = container_of(vb, 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_readl(isi, ISI_STATUS) & ISI_CTRL_CDC) {
        dev_err(isi->icd->parent, "Already in frame handling.\n");
        return;
    }

    isi_writel(isi, ISI_DMA_C_DSCR, 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);

    /* Enable linked list */
    cfg1 |= isi->pdata->frate | ISI_CFG1_DISCR;

    /* Enable codec path and ISI */
    ctrl = ISI_CTRL_CDC | ISI_CTRL_EN;
    isi_writel(isi, ISI_CTRL, ctrl);
    isi_writel(isi, ISI_CFG1, cfg1);
}

static void buffer_queue(struct vb2_buffer *vb)
{
    struct soc_camera_device *icd = soc_camera_from_vb2q(vb->vb2_queue);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    struct frame_buffer *buf = container_of(vb, struct frame_buffer, vb);
    unsigned long flags = 0;

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

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

static int start_streaming(struct vb2_queue *vq, unsigned int count)
{
    struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;

    u32 sr = 0;
    int ret;

    spin_lock_irq(&isi->lock);
    isi->state = ISI_STATE_IDLE;
    /* Clear any pending SOF interrupt */
    sr = isi_readl(isi, ISI_STATUS);
    /* Enable VSYNC interrupt for SOF */
    isi_writel(isi, ISI_INTEN, ISI_SR_VSYNC);
    isi_writel(isi, ISI_CTRL, ISI_CTRL_EN);
    spin_unlock_irq(&isi->lock);

    dev_dbg(icd->parent, "Waiting for SOF\n");
    ret = wait_event_interruptible(isi->vsync_wq,
                       isi->state != ISI_STATE_IDLE);
    if (ret)
        goto err;

    if (isi->state != ISI_STATE_READY) {
        ret = -EIO;
        goto err;
    }

    spin_lock_irq(&isi->lock);
    isi->state = ISI_STATE_WAIT_SOF;
    isi_writel(isi, ISI_INTDIS, ISI_SR_VSYNC);
    if (count)
        start_dma(isi, isi->active);
    spin_unlock_irq(&isi->lock);

    return 0;
err:
    isi->active = NULL;
    isi->sequence = 0;
    INIT_LIST_HEAD(&isi->video_buffer_list);
    return ret;
}

/* abort streaming and wait for last buffer */
static int stop_streaming(struct vb2_queue *vq)
{
    struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    struct frame_buffer *buf, *node;
    int ret = 0;
    unsigned long timeout;

    spin_lock_irq(&isi->lock);
    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_STATE_ERROR);
    }
    spin_unlock_irq(&isi->lock);

    timeout = jiffies + FRAME_INTERVAL_MILLI_SEC * HZ;
    /* 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(icd->parent,
            "Timeout waiting for finishing codec request\n");
        return -ETIMEDOUT;
    }

    /* 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(icd->parent, "Disable ISI timed out\n");

    return ret;
}

static 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,
    .wait_prepare       = soc_camera_unlock,
    .wait_finish        = soc_camera_lock,
};

/* ------------------------------------------------------------------
    SOC camera operations for the device
   ------------------------------------------------------------------*/
static int isi_camera_init_videobuf(struct vb2_queue *q,
                     struct soc_camera_device *icd)
{
    q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    q->io_modes = VB2_MMAP;
    q->drv_priv = icd;
    q->buf_struct_size = sizeof(struct frame_buffer);
    q->ops = &isi_video_qops;
    q->mem_ops = &vb2_dma_contig_memops;

    return vb2_queue_init(q);
}

static int isi_camera_set_fmt(struct soc_camera_device *icd,
                  struct v4l2_format *f)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    const struct soc_camera_format_xlate *xlate;
    struct v4l2_pix_format *pix = &f->fmt.pix;
    struct v4l2_mbus_framefmt mf;
    int ret;

    xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
    if (!xlate) {
        dev_warn(icd->parent, "Format %x not found\n",
             pix->pixelformat);
        return -EINVAL;
    }

    dev_dbg(icd->parent, "Plan to set format %dx%d\n",
            pix->width, pix->height);

    mf.width    = pix->width;
    mf.height   = pix->height;
    mf.field    = pix->field;
    mf.colorspace   = pix->colorspace;
    mf.code     = xlate->code;

    ret = v4l2_subdev_call(sd, video, s_mbus_fmt, &mf);
    if (ret < 0)
        return ret;

    if (mf.code != xlate->code)
        return -EINVAL;

    ret = configure_geometry(isi, pix->width, pix->height, xlate->code);
    if (ret < 0)
        return ret;

    pix->width      = mf.width;
    pix->height     = mf.height;
    pix->field      = mf.field;
    pix->colorspace     = mf.colorspace;
    icd->current_fmt    = xlate;

    dev_dbg(icd->parent, "Finally set format %dx%d\n",
        pix->width, pix->height);

    return ret;
}

static int isi_camera_try_fmt(struct soc_camera_device *icd,
                  struct v4l2_format *f)
{
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    const struct soc_camera_format_xlate *xlate;
    struct v4l2_pix_format *pix = &f->fmt.pix;
    struct v4l2_mbus_framefmt mf;
    u32 pixfmt = pix->pixelformat;
    int ret;

    xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
    if (pixfmt && !xlate) {
        dev_warn(icd->parent, "Format %x not found\n", pixfmt);
        return -EINVAL;
    }

    /* limit to Atmel ISI hardware capabilities */
    if (pix->height > MAX_SUPPORT_HEIGHT)
        pix->height = MAX_SUPPORT_HEIGHT;
    if (pix->width > MAX_SUPPORT_WIDTH)
        pix->width = MAX_SUPPORT_WIDTH;

    /* limit to sensor capabilities */
    mf.width    = pix->width;
    mf.height   = pix->height;
    mf.field    = pix->field;
    mf.colorspace   = pix->colorspace;
    mf.code     = xlate->code;

    ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
    if (ret < 0)
        return ret;

    pix->width  = mf.width;
    pix->height = mf.height;
    pix->colorspace = mf.colorspace;

    switch (mf.field) {
    case V4L2_FIELD_ANY:
        pix->field = V4L2_FIELD_NONE;
        break;
    case V4L2_FIELD_NONE:
        break;
    default:
        dev_err(icd->parent, "Field type %d unsupported.\n",
            mf.field);
        ret = -EINVAL;
    }

    return ret;
}

static const struct soc_mbus_pixelfmt isi_camera_formats[] = {
    {
        .fourcc         = V4L2_PIX_FMT_YUYV,
        .name           = "Packed YUV422 16 bit",
        .bits_per_sample    = 8,
        .packing        = SOC_MBUS_PACKING_2X8_PADHI,
        .order          = SOC_MBUS_ORDER_LE,
        .layout         = SOC_MBUS_LAYOUT_PACKED,
    },
};

/* This will be corrected as we get more formats */
static bool isi_camera_packing_supported(const struct soc_mbus_pixelfmt *fmt)
{
    return  fmt->packing == SOC_MBUS_PACKING_NONE ||
        (fmt->bits_per_sample == 8 &&
         fmt->packing == SOC_MBUS_PACKING_2X8_PADHI) ||
        (fmt->bits_per_sample > 8 &&
         fmt->packing == SOC_MBUS_PACKING_EXTEND16);
}

#define ISI_BUS_PARAM (V4L2_MBUS_MASTER |   \
        V4L2_MBUS_HSYNC_ACTIVE_HIGH |   \
        V4L2_MBUS_HSYNC_ACTIVE_LOW |    \
        V4L2_MBUS_VSYNC_ACTIVE_HIGH |   \
        V4L2_MBUS_VSYNC_ACTIVE_LOW |    \
        V4L2_MBUS_PCLK_SAMPLE_RISING |  \
        V4L2_MBUS_PCLK_SAMPLE_FALLING | \
        V4L2_MBUS_DATA_ACTIVE_HIGH)

static int isi_camera_try_bus_param(struct soc_camera_device *icd,
                    unsigned char buswidth)
{
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
    unsigned long common_flags;
    int ret;

    ret = v4l2_subdev_call(sd, video, g_mbus_config, &cfg);
    if (!ret) {
        common_flags = soc_mbus_config_compatible(&cfg,
                              ISI_BUS_PARAM);
        if (!common_flags) {
            dev_warn(icd->parent,
                 "Flags incompatible: camera 0x%x, host 0x%x\n",
                 cfg.flags, ISI_BUS_PARAM);
            return -EINVAL;
        }
    } else if (ret != -ENOIOCTLCMD) {
        return ret;
    }

    if ((1 << (buswidth - 1)) & isi->width_flags)
        return 0;
    return -EINVAL;
}


static int isi_camera_get_formats(struct soc_camera_device *icd,
                  unsigned int idx,
                  struct soc_camera_format_xlate *xlate)
{
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    int formats = 0, ret;
    /* sensor format */
    enum v4l2_mbus_pixelcode code;
    /* soc camera host format */
    const struct soc_mbus_pixelfmt *fmt;

    ret = v4l2_subdev_call(sd, video, enum_mbus_fmt, idx, &code);
    if (ret < 0)
        /* No more formats */
        return 0;

    fmt = soc_mbus_get_fmtdesc(code);
    if (!fmt) {
        dev_err(icd->parent,
            "Invalid format code #%u: %d\n", idx, code);
        return 0;
    }

    /* This also checks support for the requested bits-per-sample */
    ret = isi_camera_try_bus_param(icd, fmt->bits_per_sample);
    if (ret < 0) {
        dev_err(icd->parent,
            "Fail to try the bus parameters.\n");
        return 0;
    }

    switch (code) {
    case V4L2_MBUS_FMT_UYVY8_2X8:
    case V4L2_MBUS_FMT_VYUY8_2X8:
    case V4L2_MBUS_FMT_YUYV8_2X8:
    case V4L2_MBUS_FMT_YVYU8_2X8:
        formats++;
        if (xlate) {
            xlate->host_fmt = &isi_camera_formats[0];
            xlate->code = code;
            xlate++;
            dev_dbg(icd->parent, "Providing format %s using code %d\n",
                isi_camera_formats[0].name, code);
        }
        break;
    default:
        if (!isi_camera_packing_supported(fmt))
            return 0;
        if (xlate)
            dev_dbg(icd->parent,
                "Providing format %s in pass-through mode\n",
                fmt->name);
    }

    /* Generic pass-through */
    formats++;
    if (xlate) {
        xlate->host_fmt = fmt;
        xlate->code = code;
        xlate++;
    }

    return formats;
}

/* Called with .video_lock held */
static int isi_camera_add_device(struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    int ret;

    if (isi->icd)
        return -EBUSY;

    ret = clk_enable(isi->pclk);
    if (ret)
        return ret;

    ret = clk_enable(isi->mck);
    if (ret) {
        clk_disable(isi->pclk);
        return ret;
    }

    isi->icd = icd;
    dev_dbg(icd->parent, "Atmel ISI Camera driver attached to camera %d\n",
         icd->devnum);
    return 0;
}
/* Called with .video_lock held */
static void isi_camera_remove_device(struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;

    BUG_ON(icd != isi->icd);

    clk_disable(isi->mck);
    clk_disable(isi->pclk);
    isi->icd = NULL;

    dev_dbg(icd->parent, "Atmel ISI Camera driver detached from camera %d\n",
         icd->devnum);
}

static unsigned int isi_camera_poll(struct file *file, poll_table *pt)
{
    struct soc_camera_device *icd = file->private_data;

    return vb2_poll(&icd->vb2_vidq, file, pt);
}

static int isi_camera_querycap(struct soc_camera_host *ici,
                   struct v4l2_capability *cap)
{
    strcpy(cap->driver, "atmel-isi");
    strcpy(cap->card, "Atmel Image Sensor Interface");
    cap->capabilities = (V4L2_CAP_VIDEO_CAPTURE |
                V4L2_CAP_STREAMING);
    return 0;
}

static int isi_camera_set_bus_param(struct soc_camera_device *icd)
{
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct atmel_isi *isi = ici->priv;
    struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
    unsigned long common_flags;
    int ret;
    u32 cfg1 = 0;

    ret = v4l2_subdev_call(sd, video, g_mbus_config, &cfg);
    if (!ret) {
        common_flags = soc_mbus_config_compatible(&cfg,
                              ISI_BUS_PARAM);
        if (!common_flags) {
            dev_warn(icd->parent,
                 "Flags incompatible: camera 0x%x, host 0x%x\n",
                 cfg.flags, ISI_BUS_PARAM);
            return -EINVAL;
        }
    } else if (ret != -ENOIOCTLCMD) {
        return ret;
    } else {
        common_flags = ISI_BUS_PARAM;
    }
    dev_dbg(icd->parent, "Flags cam: 0x%x host: 0x%x common: 0x%lx\n",
        cfg.flags, ISI_BUS_PARAM, common_flags);

    /* Make choises, based on platform preferences */
    if ((common_flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH) &&
        (common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)) {
        if (isi->pdata->hsync_act_low)
            common_flags &= ~V4L2_MBUS_HSYNC_ACTIVE_HIGH;
        else
            common_flags &= ~V4L2_MBUS_HSYNC_ACTIVE_LOW;
    }

    if ((common_flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH) &&
        (common_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)) {
        if (isi->pdata->vsync_act_low)
            common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_HIGH;
        else
            common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_LOW;
    }

    if ((common_flags & V4L2_MBUS_PCLK_SAMPLE_RISING) &&
        (common_flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)) {
        if (isi->pdata->pclk_act_falling)
            common_flags &= ~V4L2_MBUS_PCLK_SAMPLE_RISING;
        else
            common_flags &= ~V4L2_MBUS_PCLK_SAMPLE_FALLING;
    }

    cfg.flags = common_flags;
    ret = v4l2_subdev_call(sd, video, s_mbus_config, &cfg);
    if (ret < 0 && ret != -ENOIOCTLCMD) {
        dev_dbg(icd->parent, "camera s_mbus_config(0x%lx) returned %d\n",
            common_flags, ret);
        return ret;
    }

    /* set bus param for ISI */
    if (common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)
        cfg1 |= ISI_CFG1_HSYNC_POL_ACTIVE_LOW;
    if (common_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
        cfg1 |= ISI_CFG1_VSYNC_POL_ACTIVE_LOW;
    if (common_flags & V4L2_MBUS_PCLK_SAMPLE_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;

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

    return 0;
}

static struct soc_camera_host_ops isi_soc_camera_host_ops = {
    .owner      = THIS_MODULE,
    .add        = isi_camera_add_device,
    .remove     = isi_camera_remove_device,
    .set_fmt    = isi_camera_set_fmt,
    .try_fmt    = isi_camera_try_fmt,
    .get_formats    = isi_camera_get_formats,
    .init_videobuf2 = isi_camera_init_videobuf,
    .poll       = isi_camera_poll,
    .querycap   = isi_camera_querycap,
    .set_bus_param  = isi_camera_set_bus_param,
};

/* -----------------------------------------------------------------------*/
static int __devexit atmel_isi_remove(struct platform_device *pdev)
{
    struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
    struct atmel_isi *isi = container_of(soc_host,
                    struct atmel_isi, soc_host);

    free_irq(isi->irq, isi);
    soc_camera_host_unregister(soc_host);
    vb2_dma_contig_cleanup_ctx(isi->alloc_ctx);
    dma_free_coherent(&pdev->dev,
            sizeof(struct fbd) * MAX_BUFFER_NUM,
            isi->p_fb_descriptors,
            isi->fb_descriptors_phys);

    iounmap(isi->regs);
    clk_unprepare(isi->mck);
    clk_put(isi->mck);
    clk_unprepare(isi->pclk);
    clk_put(isi->pclk);
    kfree(isi);

    return 0;
}

static int __devinit atmel_isi_probe(struct platform_device *pdev)
{
    unsigned int irq;
    struct atmel_isi *isi;
    struct clk *pclk;
    struct resource *regs;
    int ret, i;
    struct device *dev = &pdev->dev;
    struct soc_camera_host *soc_host;
    struct isi_platform_data *pdata;

    pdata = dev->platform_data;
    if (!pdata || !pdata->data_width_flags || !pdata->mck_hz) {
        dev_err(&pdev->dev,
            "No config available for Atmel ISI\n");
        return -EINVAL;
    }

    regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!regs)
        return -ENXIO;

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

    ret = clk_prepare(pclk);
    if (ret)
        goto err_clk_prepare_pclk;

    isi = kzalloc(sizeof(struct atmel_isi), GFP_KERNEL);
    if (!isi) {
        ret = -ENOMEM;
        dev_err(&pdev->dev, "Can't allocate interface!\n");
        goto err_alloc_isi;
    }

    isi->pclk = pclk;
    isi->pdata = pdata;
    isi->active = NULL;
    spin_lock_init(&isi->lock);
    init_waitqueue_head(&isi->vsync_wq);
    INIT_LIST_HEAD(&isi->video_buffer_list);
    INIT_LIST_HEAD(&isi->dma_desc_head);

    /* Get ISI_MCK, provided by programmable clock or external clock */
    isi->mck = clk_get(dev, "isi_mck");
    if (IS_ERR(isi->mck)) {
        dev_err(dev, "Failed to get isi_mck\n");
        ret = PTR_ERR(isi->mck);
        goto err_clk_get;
    }

    ret = clk_prepare(isi->mck);
    if (ret)
        goto err_clk_prepare_mck;

    /* Set ISI_MCK's frequency, it should be faster than pixel clock */
    ret = clk_set_rate(isi->mck, pdata->mck_hz);
    if (ret < 0)
        goto err_set_mck_rate;

    isi->p_fb_descriptors = dma_alloc_coherent(&pdev->dev,
                sizeof(struct fbd) * MAX_BUFFER_NUM,
                &isi->fb_descriptors_phys,
                GFP_KERNEL);
    if (!isi->p_fb_descriptors) {
        ret = -ENOMEM;
        dev_err(&pdev->dev, "Can't allocate descriptors!\n");
        goto err_alloc_descriptors;
    }

    for (i = 0; i < MAX_BUFFER_NUM; 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->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
    if (IS_ERR(isi->alloc_ctx)) {
        ret = PTR_ERR(isi->alloc_ctx);
        goto err_alloc_ctx;
    }

    isi->regs = ioremap(regs->start, resource_size(regs));
    if (!isi->regs) {
        ret = -ENOMEM;
        goto err_ioremap;
    }

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

    isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);

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

    ret = request_irq(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;

    soc_host        = &isi->soc_host;
    soc_host->drv_name  = "isi-camera";
    soc_host->ops       = &isi_soc_camera_host_ops;
    soc_host->priv      = isi;
    soc_host->v4l2_dev.dev  = &pdev->dev;
    soc_host->nr        = pdev->id;

    ret = soc_camera_host_register(soc_host);
    if (ret) {
        dev_err(&pdev->dev, "Unable to register soc camera host\n");
        goto err_register_soc_camera_host;
    }
    return 0;

err_register_soc_camera_host:
    free_irq(isi->irq, isi);
err_req_irq:
    iounmap(isi->regs);
err_ioremap:
    vb2_dma_contig_cleanup_ctx(isi->alloc_ctx);
err_alloc_ctx:
    dma_free_coherent(&pdev->dev,
            sizeof(struct fbd) * MAX_BUFFER_NUM,
            isi->p_fb_descriptors,
            isi->fb_descriptors_phys);
err_alloc_descriptors:
err_set_mck_rate:
    clk_unprepare(isi->mck);
err_clk_prepare_mck:
    clk_put(isi->mck);
err_clk_get:
    kfree(isi);
err_alloc_isi:
    clk_unprepare(pclk);
err_clk_prepare_pclk:
    clk_put(pclk);

    return ret;
}

static struct platform_driver atmel_isi_driver = {
    .probe      = atmel_isi_probe,
    .remove     = __devexit_p(atmel_isi_remove),
    .driver     = {
        .name = "atmel_isi",
        .owner = THIS_MODULE,
    },
};

static int __init atmel_isi_init_module(void)
{
    return  platform_driver_probe(&atmel_isi_driver, &atmel_isi_probe);
}

static void __exit atmel_isi_exit(void)
{
    platform_driver_unregister(&atmel_isi_driver);
}
module_init(atmel_isi_init_module);
module_exit(atmel_isi_exit);

MODULE_AUTHOR("Josh Wu <[email protected]>");
MODULE_DESCRIPTION("The V4L2 driver for Atmel Linux");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("video");