mx1_camera.c

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/*
 * V4L2 Driver for i.MXL/i.MXL camera (CSI) host
 *
 * Copyright (C) 2008, Paulius Zaleckas <[email protected]>
 * Copyright (C) 2009, Darius Augulis <[email protected]>
 *
 * Based on PXA SoC camera driver
 * Copyright (C) 2006, Sascha Hauer, Pengutronix
 * Copyright (C) 2008, Guennadi Liakhovetski <[email protected]>
 *
 * 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/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/videodev2.h>

#include <media/soc_camera.h>
#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/videobuf-dma-contig.h>
#include <media/soc_mediabus.h>

#include <asm/dma.h>
#include <asm/fiq.h>
#include <mach/dma-mx1-mx2.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
#include <linux/platform_data/camera-mx1.h>

/*
 * CSI registers
 */
#define CSICR1      0x00            /* CSI Control Register 1 */
#define CSISR       0x08            /* CSI Status Register */
#define CSIRXR      0x10            /* CSI RxFIFO Register */

#define CSICR1_RXFF_LEVEL(x)    (((x) & 0x3) << 19)
#define CSICR1_SOF_POL      (1 << 17)
#define CSICR1_SOF_INTEN    (1 << 16)
#define CSICR1_MCLKDIV(x)   (((x) & 0xf) << 12)
#define CSICR1_MCLKEN       (1 << 9)
#define CSICR1_FCC      (1 << 8)
#define CSICR1_BIG_ENDIAN   (1 << 7)
#define CSICR1_CLR_RXFIFO   (1 << 5)
#define CSICR1_GCLK_MODE    (1 << 4)
#define CSICR1_DATA_POL     (1 << 2)
#define CSICR1_REDGE        (1 << 1)
#define CSICR1_EN       (1 << 0)

#define CSISR_SFF_OR_INT    (1 << 25)
#define CSISR_RFF_OR_INT    (1 << 24)
#define CSISR_STATFF_INT    (1 << 21)
#define CSISR_RXFF_INT      (1 << 18)
#define CSISR_SOF_INT       (1 << 16)
#define CSISR_DRDY      (1 << 0)

#define DRIVER_VERSION "0.0.2"
#define DRIVER_NAME "mx1-camera"

#define CSI_IRQ_MASK    (CSISR_SFF_OR_INT | CSISR_RFF_OR_INT | \
            CSISR_STATFF_INT | CSISR_RXFF_INT | CSISR_SOF_INT)

#define CSI_BUS_FLAGS   (V4L2_MBUS_MASTER | V4L2_MBUS_HSYNC_ACTIVE_HIGH | \
            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 | V4L2_MBUS_DATA_ACTIVE_LOW)

#define MAX_VIDEO_MEM 16    /* Video memory limit in megabytes */

/*
 * Structures
 */

/* buffer for one video frame */
struct mx1_buffer {
    /* common v4l buffer stuff -- must be first */
    struct videobuf_buffer      vb;
    enum v4l2_mbus_pixelcode    code;
    int             inwork;
};

/*
 * i.MX1/i.MXL is only supposed to handle one camera on its Camera Sensor
 * Interface. If anyone ever builds hardware to enable more than
 * one camera, they will have to modify this driver too
 */
struct mx1_camera_dev {
    struct soc_camera_host      soc_host;
    struct soc_camera_device    *icd;
    struct mx1_camera_pdata     *pdata;
    struct mx1_buffer       *active;
    struct resource         *res;
    struct clk          *clk;
    struct list_head        capture;

    void __iomem            *base;
    int             dma_chan;
    unsigned int            irq;
    unsigned long           mclk;

    spinlock_t          lock;
};

/*
 *  Videobuf operations
 */
static int mx1_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
                  unsigned int *size)
{
    struct soc_camera_device *icd = vq->priv_data;

    *size = icd->sizeimage;

    if (!*count)
        *count = 32;

    if (*size * *count > MAX_VIDEO_MEM * 1024 * 1024)
        *count = (MAX_VIDEO_MEM * 1024 * 1024) / *size;

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

    return 0;
}

static void free_buffer(struct videobuf_queue *vq, struct mx1_buffer *buf)
{
    struct soc_camera_device *icd = vq->priv_data;
    struct videobuf_buffer *vb = &buf->vb;

    BUG_ON(in_interrupt());

    dev_dbg(icd->parent, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
        vb, vb->baddr, vb->bsize);

    /*
     * This waits until this buffer is out of danger, i.e., until it is no
     * longer in STATE_QUEUED or STATE_ACTIVE
     */
    videobuf_waiton(vq, vb, 0, 0);
    videobuf_dma_contig_free(vq, vb);

    vb->state = VIDEOBUF_NEEDS_INIT;
}

static int mx1_videobuf_prepare(struct videobuf_queue *vq,
        struct videobuf_buffer *vb, enum v4l2_field field)
{
    struct soc_camera_device *icd = vq->priv_data;
    struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
    int ret;

    dev_dbg(icd->parent, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
        vb, vb->baddr, vb->bsize);

    /* Added list head initialization on alloc */
    WARN_ON(!list_empty(&vb->queue));

    BUG_ON(NULL == icd->current_fmt);

    /*
     * I think, in buf_prepare you only have to protect global data,
     * the actual buffer is yours
     */
    buf->inwork = 1;

    if (buf->code   != icd->current_fmt->code ||
        vb->width   != icd->user_width ||
        vb->height  != icd->user_height ||
        vb->field   != field) {
        buf->code   = icd->current_fmt->code;
        vb->width   = icd->user_width;
        vb->height  = icd->user_height;
        vb->field   = field;
        vb->state   = VIDEOBUF_NEEDS_INIT;
    }

    vb->size = icd->sizeimage;
    if (0 != vb->baddr && vb->bsize < vb->size) {
        ret = -EINVAL;
        goto out;
    }

    if (vb->state == VIDEOBUF_NEEDS_INIT) {
        ret = videobuf_iolock(vq, vb, NULL);
        if (ret)
            goto fail;

        vb->state = VIDEOBUF_PREPARED;
    }

    buf->inwork = 0;

    return 0;

fail:
    free_buffer(vq, buf);
out:
    buf->inwork = 0;
    return ret;
}

static int mx1_camera_setup_dma(struct mx1_camera_dev *pcdev)
{
    struct videobuf_buffer *vbuf = &pcdev->active->vb;
    struct device *dev = pcdev->icd->parent;
    int ret;

    if (unlikely(!pcdev->active)) {
        dev_err(dev, "DMA End IRQ with no active buffer\n");
        return -EFAULT;
    }

    /* setup sg list for future DMA */
    ret = imx_dma_setup_single(pcdev->dma_chan,
        videobuf_to_dma_contig(vbuf),
        vbuf->size, pcdev->res->start +
        CSIRXR, DMA_MODE_READ);
    if (unlikely(ret))
        dev_err(dev, "Failed to setup DMA sg list\n");

    return ret;
}

/* Called under spinlock_irqsave(&pcdev->lock, ...) */
static void mx1_videobuf_queue(struct videobuf_queue *vq,
                        struct videobuf_buffer *vb)
{
    struct soc_camera_device *icd = vq->priv_data;
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx1_camera_dev *pcdev = ici->priv;
    struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);

    dev_dbg(icd->parent, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
        vb, vb->baddr, vb->bsize);

    list_add_tail(&vb->queue, &pcdev->capture);

    vb->state = VIDEOBUF_ACTIVE;

    if (!pcdev->active) {
        pcdev->active = buf;

        /* setup sg list for future DMA */
        if (!mx1_camera_setup_dma(pcdev)) {
            unsigned int temp;
            /* enable SOF irq */
            temp = __raw_readl(pcdev->base + CSICR1) |
                            CSICR1_SOF_INTEN;
            __raw_writel(temp, pcdev->base + CSICR1);
        }
    }
}

static void mx1_videobuf_release(struct videobuf_queue *vq,
                 struct videobuf_buffer *vb)
{
    struct mx1_buffer *buf = container_of(vb, struct mx1_buffer, vb);
#ifdef DEBUG
    struct soc_camera_device *icd = vq->priv_data;
    struct device *dev = icd->parent;

    dev_dbg(dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
        vb, vb->baddr, vb->bsize);

    switch (vb->state) {
    case VIDEOBUF_ACTIVE:
        dev_dbg(dev, "%s (active)\n", __func__);
        break;
    case VIDEOBUF_QUEUED:
        dev_dbg(dev, "%s (queued)\n", __func__);
        break;
    case VIDEOBUF_PREPARED:
        dev_dbg(dev, "%s (prepared)\n", __func__);
        break;
    default:
        dev_dbg(dev, "%s (unknown)\n", __func__);
        break;
    }
#endif

    free_buffer(vq, buf);
}

static void mx1_camera_wakeup(struct mx1_camera_dev *pcdev,
                  struct videobuf_buffer *vb,
                  struct mx1_buffer *buf)
{
    /* _init is used to debug races, see comment in mx1_camera_reqbufs() */
    list_del_init(&vb->queue);
    vb->state = VIDEOBUF_DONE;
    do_gettimeofday(&vb->ts);
    vb->field_count++;
    wake_up(&vb->done);

    if (list_empty(&pcdev->capture)) {
        pcdev->active = NULL;
        return;
    }

    pcdev->active = list_entry(pcdev->capture.next,
                   struct mx1_buffer, vb.queue);

    /* setup sg list for future DMA */
    if (likely(!mx1_camera_setup_dma(pcdev))) {
        unsigned int temp;

        /* enable SOF irq */
        temp = __raw_readl(pcdev->base + CSICR1) | CSICR1_SOF_INTEN;
        __raw_writel(temp, pcdev->base + CSICR1);
    }
}

static void mx1_camera_dma_irq(int channel, void *data)
{
    struct mx1_camera_dev *pcdev = data;
    struct device *dev = pcdev->icd->parent;
    struct mx1_buffer *buf;
    struct videobuf_buffer *vb;
    unsigned long flags;

    spin_lock_irqsave(&pcdev->lock, flags);

    imx_dma_disable(channel);

    if (unlikely(!pcdev->active)) {
        dev_err(dev, "DMA End IRQ with no active buffer\n");
        goto out;
    }

    vb = &pcdev->active->vb;
    buf = container_of(vb, struct mx1_buffer, vb);
    WARN_ON(buf->inwork || list_empty(&vb->queue));
    dev_dbg(dev, "%s (vb=0x%p) 0x%08lx %d\n", __func__,
        vb, vb->baddr, vb->bsize);

    mx1_camera_wakeup(pcdev, vb, buf);
out:
    spin_unlock_irqrestore(&pcdev->lock, flags);
}

static struct videobuf_queue_ops mx1_videobuf_ops = {
    .buf_setup  = mx1_videobuf_setup,
    .buf_prepare    = mx1_videobuf_prepare,
    .buf_queue  = mx1_videobuf_queue,
    .buf_release    = mx1_videobuf_release,
};

static void mx1_camera_init_videobuf(struct videobuf_queue *q,
                     struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx1_camera_dev *pcdev = ici->priv;

    videobuf_queue_dma_contig_init(q, &mx1_videobuf_ops, icd->parent,
                &pcdev->lock, V4L2_BUF_TYPE_VIDEO_CAPTURE,
                V4L2_FIELD_NONE,
                sizeof(struct mx1_buffer), icd, &icd->video_lock);
}

static int mclk_get_divisor(struct mx1_camera_dev *pcdev)
{
    unsigned int mclk = pcdev->mclk;
    unsigned long div;
    unsigned long lcdclk;

    lcdclk = clk_get_rate(pcdev->clk);

    /*
     * We verify platform_mclk_10khz != 0, so if anyone breaks it, here
     * they get a nice Oops
     */
    div = (lcdclk + 2 * mclk - 1) / (2 * mclk) - 1;

    dev_dbg(pcdev->icd->parent,
        "System clock %lukHz, target freq %dkHz, divisor %lu\n",
        lcdclk / 1000, mclk / 1000, div);

    return div;
}

static void mx1_camera_activate(struct mx1_camera_dev *pcdev)
{
    unsigned int csicr1 = CSICR1_EN;

    dev_dbg(pcdev->icd->parent, "Activate device\n");

    clk_prepare_enable(pcdev->clk);

    /* enable CSI before doing anything else */
    __raw_writel(csicr1, pcdev->base + CSICR1);

    csicr1 |= CSICR1_MCLKEN | CSICR1_FCC | CSICR1_GCLK_MODE;
    csicr1 |= CSICR1_MCLKDIV(mclk_get_divisor(pcdev));
    csicr1 |= CSICR1_RXFF_LEVEL(2); /* 16 words */

    __raw_writel(csicr1, pcdev->base + CSICR1);
}

static void mx1_camera_deactivate(struct mx1_camera_dev *pcdev)
{
    dev_dbg(pcdev->icd->parent, "Deactivate device\n");

    /* Disable all CSI interface */
    __raw_writel(0x00, pcdev->base + CSICR1);

    clk_disable_unprepare(pcdev->clk);
}

/*
 * The following two functions absolutely depend on the fact, that
 * there can be only one camera on i.MX1/i.MXL camera sensor interface
 */
static int mx1_camera_add_device(struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx1_camera_dev *pcdev = ici->priv;

    if (pcdev->icd)
        return -EBUSY;

    dev_info(icd->parent, "MX1 Camera driver attached to camera %d\n",
         icd->devnum);

    mx1_camera_activate(pcdev);

    pcdev->icd = icd;

    return 0;
}

static void mx1_camera_remove_device(struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx1_camera_dev *pcdev = ici->priv;
    unsigned int csicr1;

    BUG_ON(icd != pcdev->icd);

    /* disable interrupts */
    csicr1 = __raw_readl(pcdev->base + CSICR1) & ~CSI_IRQ_MASK;
    __raw_writel(csicr1, pcdev->base + CSICR1);

    /* Stop DMA engine */
    imx_dma_disable(pcdev->dma_chan);

    dev_info(icd->parent, "MX1 Camera driver detached from camera %d\n",
         icd->devnum);

    mx1_camera_deactivate(pcdev);

    pcdev->icd = NULL;
}

static int mx1_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 mx1_camera_dev *pcdev = ici->priv;
    struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
    unsigned long common_flags;
    unsigned int csicr1;
    int ret;

    /* MX1 supports only 8bit buswidth */
    ret = v4l2_subdev_call(sd, video, g_mbus_config, &cfg);
    if (!ret) {
        common_flags = soc_mbus_config_compatible(&cfg, CSI_BUS_FLAGS);
        if (!common_flags) {
            dev_warn(icd->parent,
                 "Flags incompatible: camera 0x%x, host 0x%x\n",
                 cfg.flags, CSI_BUS_FLAGS);
            return -EINVAL;
        }
    } else if (ret != -ENOIOCTLCMD) {
        return ret;
    } else {
        common_flags = CSI_BUS_FLAGS;
    }

    /* Make choises, based on platform choice */
    if ((common_flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH) &&
        (common_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)) {
            if (!pcdev->pdata ||
                 pcdev->pdata->flags & MX1_CAMERA_VSYNC_HIGH)
                common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_LOW;
            else
                common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_HIGH;
    }

    if ((common_flags & V4L2_MBUS_PCLK_SAMPLE_RISING) &&
        (common_flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)) {
            if (!pcdev->pdata ||
                 pcdev->pdata->flags & MX1_CAMERA_PCLK_RISING)
                common_flags &= ~V4L2_MBUS_PCLK_SAMPLE_FALLING;
            else
                common_flags &= ~V4L2_MBUS_PCLK_SAMPLE_RISING;
    }

    if ((common_flags & V4L2_MBUS_DATA_ACTIVE_HIGH) &&
        (common_flags & V4L2_MBUS_DATA_ACTIVE_LOW)) {
            if (!pcdev->pdata ||
                 pcdev->pdata->flags & MX1_CAMERA_DATA_HIGH)
                common_flags &= ~V4L2_MBUS_DATA_ACTIVE_LOW;
            else
                common_flags &= ~V4L2_MBUS_DATA_ACTIVE_HIGH;
    }

    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;
    }

    csicr1 = __raw_readl(pcdev->base + CSICR1);

    if (common_flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
        csicr1 |= CSICR1_REDGE;
    if (common_flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
        csicr1 |= CSICR1_SOF_POL;
    if (common_flags & V4L2_MBUS_DATA_ACTIVE_LOW)
        csicr1 |= CSICR1_DATA_POL;

    __raw_writel(csicr1, pcdev->base + CSICR1);

    return 0;
}

static int mx1_camera_set_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;
    int ret, buswidth;

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

    buswidth = xlate->host_fmt->bits_per_sample;
    if (buswidth > 8) {
        dev_warn(icd->parent,
             "bits-per-sample %d for format %x unsupported\n",
             buswidth, pix->pixelformat);
        return -EINVAL;
    }

    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;

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

    return ret;
}

static int mx1_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;
    int ret;
    /* TODO: limit to mx1 hardware capabilities */

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

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

    /* limit to sensor capabilities */
    ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
    if (ret < 0)
        return ret;

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

    return 0;
}

static int mx1_camera_reqbufs(struct soc_camera_device *icd,
                  struct v4l2_requestbuffers *p)
{
    int i;

    /*
     * This is for locking debugging only. I removed spinlocks and now I
     * check whether .prepare is ever called on a linked buffer, or whether
     * a dma IRQ can occur for an in-work or unlinked buffer. Until now
     * it hadn't triggered
     */
    for (i = 0; i < p->count; i++) {
        struct mx1_buffer *buf = container_of(icd->vb_vidq.bufs[i],
                              struct mx1_buffer, vb);
        buf->inwork = 0;
        INIT_LIST_HEAD(&buf->vb.queue);
    }

    return 0;
}

static unsigned int mx1_camera_poll(struct file *file, poll_table *pt)
{
    struct soc_camera_device *icd = file->private_data;
    struct mx1_buffer *buf;

    buf = list_entry(icd->vb_vidq.stream.next, struct mx1_buffer,
             vb.stream);

    poll_wait(file, &buf->vb.done, pt);

    if (buf->vb.state == VIDEOBUF_DONE ||
        buf->vb.state == VIDEOBUF_ERROR)
        return POLLIN | POLLRDNORM;

    return 0;
}

static int mx1_camera_querycap(struct soc_camera_host *ici,
                   struct v4l2_capability *cap)
{
    /* cap->name is set by the friendly caller:-> */
    strlcpy(cap->card, "i.MX1/i.MXL Camera", sizeof(cap->card));
    cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;

    return 0;
}

static struct soc_camera_host_ops mx1_soc_camera_host_ops = {
    .owner      = THIS_MODULE,
    .add        = mx1_camera_add_device,
    .remove     = mx1_camera_remove_device,
    .set_bus_param  = mx1_camera_set_bus_param,
    .set_fmt    = mx1_camera_set_fmt,
    .try_fmt    = mx1_camera_try_fmt,
    .init_videobuf  = mx1_camera_init_videobuf,
    .reqbufs    = mx1_camera_reqbufs,
    .poll       = mx1_camera_poll,
    .querycap   = mx1_camera_querycap,
};

static struct fiq_handler fh = {
    .name       = "csi_sof"
};

static int __init mx1_camera_probe(struct platform_device *pdev)
{
    struct mx1_camera_dev *pcdev;
    struct resource *res;
    struct pt_regs regs;
    struct clk *clk;
    void __iomem *base;
    unsigned int irq;
    int err = 0;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    irq = platform_get_irq(pdev, 0);
    if (!res || (int)irq <= 0) {
        err = -ENODEV;
        goto exit;
    }

    clk = clk_get(&pdev->dev, "csi_clk");
    if (IS_ERR(clk)) {
        err = PTR_ERR(clk);
        goto exit;
    }

    pcdev = kzalloc(sizeof(*pcdev), GFP_KERNEL);
    if (!pcdev) {
        dev_err(&pdev->dev, "Could not allocate pcdev\n");
        err = -ENOMEM;
        goto exit_put_clk;
    }

    pcdev->res = res;
    pcdev->clk = clk;

    pcdev->pdata = pdev->dev.platform_data;

    if (pcdev->pdata)
        pcdev->mclk = pcdev->pdata->mclk_10khz * 10000;

    if (!pcdev->mclk) {
        dev_warn(&pdev->dev,
             "mclk_10khz == 0! Please, fix your platform data. "
             "Using default 20MHz\n");
        pcdev->mclk = 20000000;
    }

    INIT_LIST_HEAD(&pcdev->capture);
    spin_lock_init(&pcdev->lock);

    /*
     * Request the regions.
     */
    if (!request_mem_region(res->start, resource_size(res), DRIVER_NAME)) {
        err = -EBUSY;
        goto exit_kfree;
    }

    base = ioremap(res->start, resource_size(res));
    if (!base) {
        err = -ENOMEM;
        goto exit_release;
    }
    pcdev->irq = irq;
    pcdev->base = base;

    /* request dma */
    pcdev->dma_chan = imx_dma_request_by_prio(DRIVER_NAME, DMA_PRIO_HIGH);
    if (pcdev->dma_chan < 0) {
        dev_err(&pdev->dev, "Can't request DMA for MX1 CSI\n");
        err = -EBUSY;
        goto exit_iounmap;
    }
    dev_dbg(&pdev->dev, "got DMA channel %d\n", pcdev->dma_chan);

    imx_dma_setup_handlers(pcdev->dma_chan, mx1_camera_dma_irq, NULL,
                   pcdev);

    imx_dma_config_channel(pcdev->dma_chan, IMX_DMA_TYPE_FIFO,
                   IMX_DMA_MEMSIZE_32, MX1_DMA_REQ_CSI_R, 0);
    /* burst length : 16 words = 64 bytes */
    imx_dma_config_burstlen(pcdev->dma_chan, 0);

    /* request irq */
    err = claim_fiq(&fh);
    if (err) {
        dev_err(&pdev->dev, "Camera interrupt register failed \n");
        goto exit_free_dma;
    }

    set_fiq_handler(&mx1_camera_sof_fiq_start, &mx1_camera_sof_fiq_end -
                           &mx1_camera_sof_fiq_start);

    regs.ARM_r8 = (long)MX1_DMA_DIMR;
    regs.ARM_r9 = (long)MX1_DMA_CCR(pcdev->dma_chan);
    regs.ARM_r10 = (long)pcdev->base + CSICR1;
    regs.ARM_fp = (long)pcdev->base + CSISR;
    regs.ARM_sp = 1 << pcdev->dma_chan;
    set_fiq_regs(&regs);

    mxc_set_irq_fiq(irq, 1);
    enable_fiq(irq);

    pcdev->soc_host.drv_name    = DRIVER_NAME;
    pcdev->soc_host.ops     = &mx1_soc_camera_host_ops;
    pcdev->soc_host.priv        = pcdev;
    pcdev->soc_host.v4l2_dev.dev    = &pdev->dev;
    pcdev->soc_host.nr      = pdev->id;
    err = soc_camera_host_register(&pcdev->soc_host);
    if (err)
        goto exit_free_irq;

    dev_info(&pdev->dev, "MX1 Camera driver loaded\n");

    return 0;

exit_free_irq:
    disable_fiq(irq);
    mxc_set_irq_fiq(irq, 0);
    release_fiq(&fh);
exit_free_dma:
    imx_dma_free(pcdev->dma_chan);
exit_iounmap:
    iounmap(base);
exit_release:
    release_mem_region(res->start, resource_size(res));
exit_kfree:
    kfree(pcdev);
exit_put_clk:
    clk_put(clk);
exit:
    return err;
}

static int __exit mx1_camera_remove(struct platform_device *pdev)
{
    struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
    struct mx1_camera_dev *pcdev = container_of(soc_host,
                    struct mx1_camera_dev, soc_host);
    struct resource *res;

    imx_dma_free(pcdev->dma_chan);
    disable_fiq(pcdev->irq);
    mxc_set_irq_fiq(pcdev->irq, 0);
    release_fiq(&fh);

    clk_put(pcdev->clk);

    soc_camera_host_unregister(soc_host);

    iounmap(pcdev->base);

    res = pcdev->res;
    release_mem_region(res->start, resource_size(res));

    kfree(pcdev);

    dev_info(&pdev->dev, "MX1 Camera driver unloaded\n");

    return 0;
}

static struct platform_driver mx1_camera_driver = {
    .driver     = {
        .name   = DRIVER_NAME,
    },
    .remove     = __exit_p(mx1_camera_remove),
};

static int __init mx1_camera_init(void)
{
    return platform_driver_probe(&mx1_camera_driver, mx1_camera_probe);
}

static void __exit mx1_camera_exit(void)
{
    return platform_driver_unregister(&mx1_camera_driver);
}

module_init(mx1_camera_init);
module_exit(mx1_camera_exit);

MODULE_DESCRIPTION("i.MX1/i.MXL SoC Camera Host driver");
MODULE_AUTHOR("Paulius Zaleckas <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRIVER_VERSION);
MODULE_ALIAS("platform:" DRIVER_NAME);