mx3_camera.c

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/*
 * V4L2 Driver for i.MX3x camera host
 *
 * Copyright (C) 2008
 * Guennadi Liakhovetski, DENX Software Engineering, <[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/init.h>
#include <linux/module.h>
#include <linux/videodev2.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/vmalloc.h>
#include <linux/interrupt.h>
#include <linux/sched.h>

#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/videobuf2-dma-contig.h>
#include <media/soc_camera.h>
#include <media/soc_mediabus.h>

#include <mach/ipu.h>
#include <linux/platform_data/camera-mx3.h>
#include <linux/platform_data/dma-imx.h>

#define MX3_CAM_DRV_NAME "mx3-camera"

/* CMOS Sensor Interface Registers */
#define CSI_REG_START       0x60

#define CSI_SENS_CONF       (0x60 - CSI_REG_START)
#define CSI_SENS_FRM_SIZE   (0x64 - CSI_REG_START)
#define CSI_ACT_FRM_SIZE    (0x68 - CSI_REG_START)
#define CSI_OUT_FRM_CTRL    (0x6C - CSI_REG_START)
#define CSI_TST_CTRL        (0x70 - CSI_REG_START)
#define CSI_CCIR_CODE_1     (0x74 - CSI_REG_START)
#define CSI_CCIR_CODE_2     (0x78 - CSI_REG_START)
#define CSI_CCIR_CODE_3     (0x7C - CSI_REG_START)
#define CSI_FLASH_STROBE_1  (0x80 - CSI_REG_START)
#define CSI_FLASH_STROBE_2  (0x84 - CSI_REG_START)

#define CSI_SENS_CONF_VSYNC_POL_SHIFT       0
#define CSI_SENS_CONF_HSYNC_POL_SHIFT       1
#define CSI_SENS_CONF_DATA_POL_SHIFT        2
#define CSI_SENS_CONF_PIX_CLK_POL_SHIFT     3
#define CSI_SENS_CONF_SENS_PRTCL_SHIFT      4
#define CSI_SENS_CONF_SENS_CLKSRC_SHIFT     7
#define CSI_SENS_CONF_DATA_FMT_SHIFT        8
#define CSI_SENS_CONF_DATA_WIDTH_SHIFT      10
#define CSI_SENS_CONF_EXT_VSYNC_SHIFT       15
#define CSI_SENS_CONF_DIVRATIO_SHIFT        16

#define CSI_SENS_CONF_DATA_FMT_RGB_YUV444   (0UL << CSI_SENS_CONF_DATA_FMT_SHIFT)
#define CSI_SENS_CONF_DATA_FMT_YUV422       (2UL << CSI_SENS_CONF_DATA_FMT_SHIFT)
#define CSI_SENS_CONF_DATA_FMT_BAYER        (3UL << CSI_SENS_CONF_DATA_FMT_SHIFT)

#define MAX_VIDEO_MEM 16

struct mx3_camera_buffer {
    /* common v4l buffer stuff -- must be first */
    struct vb2_buffer           vb;
    struct list_head            queue;

    /* One descriptot per scatterlist (per frame) */
    struct dma_async_tx_descriptor      *txd;

    /* We have to "build" a scatterlist ourselves - one element per frame */
    struct scatterlist          sg;
};

struct mx3_camera_dev {
    /*
     * i.MX3x is only supposed to handle one camera on its Camera Sensor
     * Interface. If anyone ever builds hardware to enable more than one
     * camera _simultaneously_, they will have to modify this driver too
     */
    struct soc_camera_device *icd;
    struct clk      *clk;

    void __iomem        *base;

    struct mx3_camera_pdata *pdata;

    unsigned long       platform_flags;
    unsigned long       mclk;
    u16         width_flags;    /* max 15 bits */

    struct list_head    capture;
    spinlock_t      lock;       /* Protects video buffer lists */
    struct mx3_camera_buffer *active;
    size_t          buf_total;
    struct vb2_alloc_ctx    *alloc_ctx;
    enum v4l2_field     field;
    int         sequence;

    /* IDMAC / dmaengine interface */
    struct idmac_channel    *idmac_channel[1];  /* We need one channel */

    struct soc_camera_host  soc_host;
};

struct dma_chan_request {
    struct mx3_camera_dev   *mx3_cam;
    enum ipu_channel    id;
};

static u32 csi_reg_read(struct mx3_camera_dev *mx3, off_t reg)
{
    return __raw_readl(mx3->base + reg);
}

static void csi_reg_write(struct mx3_camera_dev *mx3, u32 value, off_t reg)
{
    __raw_writel(value, mx3->base + reg);
}

static struct mx3_camera_buffer *to_mx3_vb(struct vb2_buffer *vb)
{
    return container_of(vb, struct mx3_camera_buffer, vb);
}

/* Called from the IPU IDMAC ISR */
static void mx3_cam_dma_done(void *arg)
{
    struct idmac_tx_desc *desc = to_tx_desc(arg);
    struct dma_chan *chan = desc->txd.chan;
    struct idmac_channel *ichannel = to_idmac_chan(chan);
    struct mx3_camera_dev *mx3_cam = ichannel->client;

    dev_dbg(chan->device->dev, "callback cookie %d, active DMA 0x%08x\n",
        desc->txd.cookie, mx3_cam->active ? sg_dma_address(&mx3_cam->active->sg) : 0);

    spin_lock(&mx3_cam->lock);
    if (mx3_cam->active) {
        struct vb2_buffer *vb = &mx3_cam->active->vb;
        struct mx3_camera_buffer *buf = to_mx3_vb(vb);

        list_del_init(&buf->queue);
        do_gettimeofday(&vb->v4l2_buf.timestamp);
        vb->v4l2_buf.field = mx3_cam->field;
        vb->v4l2_buf.sequence = mx3_cam->sequence++;
        vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
    }

    if (list_empty(&mx3_cam->capture)) {
        mx3_cam->active = NULL;
        spin_unlock(&mx3_cam->lock);

        /*
         * stop capture - without further buffers IPU_CHA_BUF0_RDY will
         * not get updated
         */
        return;
    }

    mx3_cam->active = list_entry(mx3_cam->capture.next,
                     struct mx3_camera_buffer, queue);
    spin_unlock(&mx3_cam->lock);
}

/*
 * Videobuf operations
 */

/*
 * Calculate the __buffer__ (not data) size and number of buffers.
 */
static int mx3_videobuf_setup(struct vb2_queue *vq,
            const struct v4l2_format *fmt,
            unsigned int *count, unsigned int *num_planes,
            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 mx3_camera_dev *mx3_cam = ici->priv;

    if (!mx3_cam->idmac_channel[0])
        return -EINVAL;

    if (fmt) {
        const struct soc_camera_format_xlate *xlate = soc_camera_xlate_by_fourcc(icd,
                                fmt->fmt.pix.pixelformat);
        unsigned int bytes_per_line;
        int ret;

        if (!xlate)
            return -EINVAL;

        ret = soc_mbus_bytes_per_line(fmt->fmt.pix.width,
                          xlate->host_fmt);
        if (ret < 0)
            return ret;

        bytes_per_line = max_t(u32, fmt->fmt.pix.bytesperline, ret);

        ret = soc_mbus_image_size(xlate->host_fmt, bytes_per_line,
                      fmt->fmt.pix.height);
        if (ret < 0)
            return ret;

        sizes[0] = max_t(u32, fmt->fmt.pix.sizeimage, ret);
    } else {
        /* Called from VIDIOC_REQBUFS or in compatibility mode */
        sizes[0] = icd->sizeimage;
    }

    alloc_ctxs[0] = mx3_cam->alloc_ctx;

    if (!vq->num_buffers)
        mx3_cam->sequence = 0;

    if (!*count)
        *count = 2;

    /* If *num_planes != 0, we have already verified *count. */
    if (!*num_planes &&
        sizes[0] * *count + mx3_cam->buf_total > MAX_VIDEO_MEM * 1024 * 1024)
        *count = (MAX_VIDEO_MEM * 1024 * 1024 - mx3_cam->buf_total) /
            sizes[0];

    *num_planes = 1;

    return 0;
}

static enum pixel_fmt fourcc_to_ipu_pix(__u32 fourcc)
{
    /* Add more formats as need arises and test possibilities appear... */
    switch (fourcc) {
    case V4L2_PIX_FMT_RGB24:
        return IPU_PIX_FMT_RGB24;
    case V4L2_PIX_FMT_UYVY:
    case V4L2_PIX_FMT_RGB565:
    default:
        return IPU_PIX_FMT_GENERIC;
    }
}

static void mx3_videobuf_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 mx3_camera_dev *mx3_cam = ici->priv;
    struct mx3_camera_buffer *buf = to_mx3_vb(vb);
    struct scatterlist *sg = &buf->sg;
    struct dma_async_tx_descriptor *txd;
    struct idmac_channel *ichan = mx3_cam->idmac_channel[0];
    struct idmac_video_param *video = &ichan->params.video;
    const struct soc_mbus_pixelfmt *host_fmt = icd->current_fmt->host_fmt;
    unsigned long flags;
    dma_cookie_t cookie;
    size_t new_size;

    new_size = icd->sizeimage;

    if (vb2_plane_size(vb, 0) < new_size) {
        dev_err(icd->parent, "Buffer #%d too small (%lu < %zu)\n",
            vb->v4l2_buf.index, vb2_plane_size(vb, 0), new_size);
        goto error;
    }

    if (!buf->txd) {
        sg_dma_address(sg)  = vb2_dma_contig_plane_dma_addr(vb, 0);
        sg_dma_len(sg)      = new_size;

        txd = dmaengine_prep_slave_sg(
            &ichan->dma_chan, sg, 1, DMA_DEV_TO_MEM,
            DMA_PREP_INTERRUPT);
        if (!txd)
            goto error;

        txd->callback_param = txd;
        txd->callback       = mx3_cam_dma_done;

        buf->txd        = txd;
    } else {
        txd = buf->txd;
    }

    vb2_set_plane_payload(vb, 0, new_size);

    /* This is the configuration of one sg-element */
    video->out_pixel_fmt = fourcc_to_ipu_pix(host_fmt->fourcc);

    if (video->out_pixel_fmt == IPU_PIX_FMT_GENERIC) {
        /*
         * If the IPU DMA channel is configured to transfer generic
         * 8-bit data, we have to set up the geometry parameters
         * correctly, according to the current pixel format. The DMA
         * horizontal parameters in this case are expressed in bytes,
         * not in pixels.
         */
        video->out_width    = icd->bytesperline;
        video->out_height   = icd->user_height;
        video->out_stride   = icd->bytesperline;
    } else {
        /*
         * For IPU known formats the pixel unit will be managed
         * successfully by the IPU code
         */
        video->out_width    = icd->user_width;
        video->out_height   = icd->user_height;
        video->out_stride   = icd->user_width;
    }

#ifdef DEBUG
    /* helps to see what DMA actually has written */
    if (vb2_plane_vaddr(vb, 0))
        memset(vb2_plane_vaddr(vb, 0), 0xaa, vb2_get_plane_payload(vb, 0));
#endif

    spin_lock_irqsave(&mx3_cam->lock, flags);
    list_add_tail(&buf->queue, &mx3_cam->capture);

    if (!mx3_cam->active)
        mx3_cam->active = buf;

    spin_unlock_irq(&mx3_cam->lock);

    cookie = txd->tx_submit(txd);
    dev_dbg(icd->parent, "Submitted cookie %d DMA 0x%08x\n",
        cookie, sg_dma_address(&buf->sg));

    if (cookie >= 0)
        return;

    spin_lock_irq(&mx3_cam->lock);

    /* Submit error */
    list_del_init(&buf->queue);

    if (mx3_cam->active == buf)
        mx3_cam->active = NULL;

    spin_unlock_irqrestore(&mx3_cam->lock, flags);
error:
    vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
}

static void mx3_videobuf_release(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 mx3_camera_dev *mx3_cam = ici->priv;
    struct mx3_camera_buffer *buf = to_mx3_vb(vb);
    struct dma_async_tx_descriptor *txd = buf->txd;
    unsigned long flags;

    dev_dbg(icd->parent,
        "Release%s DMA 0x%08x, queue %sempty\n",
        mx3_cam->active == buf ? " active" : "", sg_dma_address(&buf->sg),
        list_empty(&buf->queue) ? "" : "not ");

    spin_lock_irqsave(&mx3_cam->lock, flags);

    if (mx3_cam->active == buf)
        mx3_cam->active = NULL;

    /* Doesn't hurt also if the list is empty */
    list_del_init(&buf->queue);

    if (txd) {
        buf->txd = NULL;
        if (mx3_cam->idmac_channel[0])
            async_tx_ack(txd);
    }

    spin_unlock_irqrestore(&mx3_cam->lock, flags);

    mx3_cam->buf_total -= vb2_plane_size(vb, 0);
}

static int mx3_videobuf_init(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 mx3_camera_dev *mx3_cam = ici->priv;
    struct mx3_camera_buffer *buf = to_mx3_vb(vb);

    if (!buf->txd) {
        /* This is for locking debugging only */
        INIT_LIST_HEAD(&buf->queue);
        sg_init_table(&buf->sg, 1);

        mx3_cam->buf_total += vb2_plane_size(vb, 0);
    }

    return 0;
}

static int mx3_stop_streaming(struct vb2_queue *q)
{
    struct soc_camera_device *icd = soc_camera_from_vb2q(q);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx3_camera_dev *mx3_cam = ici->priv;
    struct idmac_channel *ichan = mx3_cam->idmac_channel[0];
    struct mx3_camera_buffer *buf, *tmp;
    unsigned long flags;

    if (ichan) {
        struct dma_chan *chan = &ichan->dma_chan;
        chan->device->device_control(chan, DMA_PAUSE, 0);
    }

    spin_lock_irqsave(&mx3_cam->lock, flags);

    mx3_cam->active = NULL;

    list_for_each_entry_safe(buf, tmp, &mx3_cam->capture, queue) {
        list_del_init(&buf->queue);
        vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
    }

    spin_unlock_irqrestore(&mx3_cam->lock, flags);

    return 0;
}

static struct vb2_ops mx3_videobuf_ops = {
    .queue_setup    = mx3_videobuf_setup,
    .buf_queue  = mx3_videobuf_queue,
    .buf_cleanup    = mx3_videobuf_release,
    .buf_init   = mx3_videobuf_init,
    .wait_prepare   = soc_camera_unlock,
    .wait_finish    = soc_camera_lock,
    .stop_streaming = mx3_stop_streaming,
};

static int mx3_camera_init_videobuf(struct vb2_queue *q,
                     struct soc_camera_device *icd)
{
    q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    q->io_modes = VB2_MMAP | VB2_USERPTR;
    q->drv_priv = icd;
    q->ops = &mx3_videobuf_ops;
    q->mem_ops = &vb2_dma_contig_memops;
    q->buf_struct_size = sizeof(struct mx3_camera_buffer);

    return vb2_queue_init(q);
}

/* First part of ipu_csi_init_interface() */
static void mx3_camera_activate(struct mx3_camera_dev *mx3_cam,
                struct soc_camera_device *icd)
{
    u32 conf;
    long rate;

    /* Set default size: ipu_csi_set_window_size() */
    csi_reg_write(mx3_cam, (640 - 1) | ((480 - 1) << 16), CSI_ACT_FRM_SIZE);
    /* ...and position to 0:0: ipu_csi_set_window_pos() */
    conf = csi_reg_read(mx3_cam, CSI_OUT_FRM_CTRL) & 0xffff0000;
    csi_reg_write(mx3_cam, conf, CSI_OUT_FRM_CTRL);

    /* We use only gated clock synchronisation mode so far */
    conf = 0 << CSI_SENS_CONF_SENS_PRTCL_SHIFT;

    /* Set generic data, platform-biggest bus-width */
    conf |= CSI_SENS_CONF_DATA_FMT_BAYER;

    if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_15)
        conf |= 3 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
    else if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_10)
        conf |= 2 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
    else if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_8)
        conf |= 1 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
    else/* if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_4)*/
        conf |= 0 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;

    if (mx3_cam->platform_flags & MX3_CAMERA_CLK_SRC)
        conf |= 1 << CSI_SENS_CONF_SENS_CLKSRC_SHIFT;
    if (mx3_cam->platform_flags & MX3_CAMERA_EXT_VSYNC)
        conf |= 1 << CSI_SENS_CONF_EXT_VSYNC_SHIFT;
    if (mx3_cam->platform_flags & MX3_CAMERA_DP)
        conf |= 1 << CSI_SENS_CONF_DATA_POL_SHIFT;
    if (mx3_cam->platform_flags & MX3_CAMERA_PCP)
        conf |= 1 << CSI_SENS_CONF_PIX_CLK_POL_SHIFT;
    if (mx3_cam->platform_flags & MX3_CAMERA_HSP)
        conf |= 1 << CSI_SENS_CONF_HSYNC_POL_SHIFT;
    if (mx3_cam->platform_flags & MX3_CAMERA_VSP)
        conf |= 1 << CSI_SENS_CONF_VSYNC_POL_SHIFT;

    /* ipu_csi_init_interface() */
    csi_reg_write(mx3_cam, conf, CSI_SENS_CONF);

    clk_prepare_enable(mx3_cam->clk);
    rate = clk_round_rate(mx3_cam->clk, mx3_cam->mclk);
    dev_dbg(icd->parent, "Set SENS_CONF to %x, rate %ld\n", conf, rate);
    if (rate)
        clk_set_rate(mx3_cam->clk, rate);
}

/* Called with .video_lock held */
static int mx3_camera_add_device(struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx3_camera_dev *mx3_cam = ici->priv;

    if (mx3_cam->icd)
        return -EBUSY;

    mx3_camera_activate(mx3_cam, icd);

    mx3_cam->buf_total = 0;
    mx3_cam->icd = icd;

    dev_info(icd->parent, "MX3 Camera driver attached to camera %d\n",
         icd->devnum);

    return 0;
}

/* Called with .video_lock held */
static void mx3_camera_remove_device(struct soc_camera_device *icd)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx3_camera_dev *mx3_cam = ici->priv;
    struct idmac_channel **ichan = &mx3_cam->idmac_channel[0];

    BUG_ON(icd != mx3_cam->icd);

    if (*ichan) {
        dma_release_channel(&(*ichan)->dma_chan);
        *ichan = NULL;
    }

    clk_disable_unprepare(mx3_cam->clk);

    mx3_cam->icd = NULL;

    dev_info(icd->parent, "MX3 Camera driver detached from camera %d\n",
         icd->devnum);
}

static int test_platform_param(struct mx3_camera_dev *mx3_cam,
                   unsigned char buswidth, unsigned long *flags)
{
    /*
     * If requested data width is supported by the platform, use it or any
     * possible lower value - i.MX31 is smart enough to shift bits
     */
    if (buswidth > fls(mx3_cam->width_flags))
        return -EINVAL;

    /*
     * Platform specified synchronization and pixel clock polarities are
     * only a recommendation and are only used during probing. MX3x
     * camera interface only works in master mode, i.e., uses HSYNC and
     * VSYNC signals from the sensor
     */
    *flags = 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 |
        V4L2_MBUS_DATA_ACTIVE_LOW;

    return 0;
}

static int mx3_camera_try_bus_param(struct soc_camera_device *icd,
                    const unsigned int depth)
{
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx3_camera_dev *mx3_cam = ici->priv;
    struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
    unsigned long bus_flags, common_flags;
    int ret = test_platform_param(mx3_cam, depth, &bus_flags);

    dev_dbg(icd->parent, "request bus width %d bit: %d\n", depth, ret);

    if (ret < 0)
        return ret;

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

    return 0;
}

static bool chan_filter(struct dma_chan *chan, void *arg)
{
    struct dma_chan_request *rq = arg;
    struct mx3_camera_pdata *pdata;

    if (!imx_dma_is_ipu(chan))
        return false;

    if (!rq)
        return false;

    pdata = rq->mx3_cam->soc_host.v4l2_dev.dev->platform_data;

    return rq->id == chan->chan_id &&
        pdata->dma_dev == chan->device->dev;
}

static const struct soc_mbus_pixelfmt mx3_camera_formats[] = {
    {
        .fourcc         = V4L2_PIX_FMT_SBGGR8,
        .name           = "Bayer BGGR (sRGB) 8 bit",
        .bits_per_sample    = 8,
        .packing        = SOC_MBUS_PACKING_NONE,
        .order          = SOC_MBUS_ORDER_LE,
        .layout         = SOC_MBUS_LAYOUT_PACKED,
    }, {
        .fourcc         = V4L2_PIX_FMT_GREY,
        .name           = "Monochrome 8 bit",
        .bits_per_sample    = 8,
        .packing        = SOC_MBUS_PACKING_NONE,
        .order          = SOC_MBUS_ORDER_LE,
        .layout         = SOC_MBUS_LAYOUT_PACKED,
    },
};

/* This will be corrected as we get more formats */
static bool mx3_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);
}

static int mx3_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);
    struct device *dev = icd->parent;
    int formats = 0, ret;
    enum v4l2_mbus_pixelcode code;
    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_warn(icd->parent,
             "Unsupported format code #%u: %d\n", idx, code);
        return 0;
    }

    /* This also checks support for the requested bits-per-sample */
    ret = mx3_camera_try_bus_param(icd, fmt->bits_per_sample);
    if (ret < 0)
        return 0;

    switch (code) {
    case V4L2_MBUS_FMT_SBGGR10_1X10:
        formats++;
        if (xlate) {
            xlate->host_fmt = &mx3_camera_formats[0];
            xlate->code = code;
            xlate++;
            dev_dbg(dev, "Providing format %s using code %d\n",
                mx3_camera_formats[0].name, code);
        }
        break;
    case V4L2_MBUS_FMT_Y10_1X10:
        formats++;
        if (xlate) {
            xlate->host_fmt = &mx3_camera_formats[1];
            xlate->code = code;
            xlate++;
            dev_dbg(dev, "Providing format %s using code %d\n",
                mx3_camera_formats[1].name, code);
        }
        break;
    default:
        if (!mx3_camera_packing_supported(fmt))
            return 0;
    }

    /* Generic pass-through */
    formats++;
    if (xlate) {
        xlate->host_fmt = fmt;
        xlate->code = code;
        dev_dbg(dev, "Providing format %c%c%c%c in pass-through mode\n",
            (fmt->fourcc >> (0*8)) & 0xFF,
            (fmt->fourcc >> (1*8)) & 0xFF,
            (fmt->fourcc >> (2*8)) & 0xFF,
            (fmt->fourcc >> (3*8)) & 0xFF);
        xlate++;
    }

    return formats;
}

static void configure_geometry(struct mx3_camera_dev *mx3_cam,
                   unsigned int width, unsigned int height,
                   const struct soc_mbus_pixelfmt *fmt)
{
    u32 ctrl, width_field, height_field;

    if (fourcc_to_ipu_pix(fmt->fourcc) == IPU_PIX_FMT_GENERIC) {
        /*
         * As the CSI will be configured to output BAYER, here
         * the width parameter count the number of samples to
         * capture to complete the whole image width.
         */
        unsigned int num, den;
        int ret = soc_mbus_samples_per_pixel(fmt, &num, &den);
        BUG_ON(ret < 0);
        width = width * num / den;
    }

    /* Setup frame size - this cannot be changed on-the-fly... */
    width_field = width - 1;
    height_field = height - 1;
    csi_reg_write(mx3_cam, width_field | (height_field << 16), CSI_SENS_FRM_SIZE);

    csi_reg_write(mx3_cam, width_field << 16, CSI_FLASH_STROBE_1);
    csi_reg_write(mx3_cam, (height_field << 16) | 0x22, CSI_FLASH_STROBE_2);

    csi_reg_write(mx3_cam, width_field | (height_field << 16), CSI_ACT_FRM_SIZE);

    /* ...and position */
    ctrl = csi_reg_read(mx3_cam, CSI_OUT_FRM_CTRL) & 0xffff0000;
    /* Sensor does the cropping */
    csi_reg_write(mx3_cam, ctrl | 0 | (0 << 8), CSI_OUT_FRM_CTRL);
}

static int acquire_dma_channel(struct mx3_camera_dev *mx3_cam)
{
    dma_cap_mask_t mask;
    struct dma_chan *chan;
    struct idmac_channel **ichan = &mx3_cam->idmac_channel[0];
    /* We have to use IDMAC_IC_7 for Bayer / generic data */
    struct dma_chan_request rq = {.mx3_cam = mx3_cam,
                      .id = IDMAC_IC_7};

    dma_cap_zero(mask);
    dma_cap_set(DMA_SLAVE, mask);
    dma_cap_set(DMA_PRIVATE, mask);
    chan = dma_request_channel(mask, chan_filter, &rq);
    if (!chan)
        return -EBUSY;

    *ichan = to_idmac_chan(chan);
    (*ichan)->client = mx3_cam;

    return 0;
}

/*
 * FIXME: learn to use stride != width, then we can keep stride properly aligned
 * and support arbitrary (even) widths.
 */
static inline void stride_align(__u32 *width)
{
    if (ALIGN(*width, 8) < 4096)
        *width = ALIGN(*width, 8);
    else
        *width = *width &  ~7;
}

/*
 * As long as we don't implement host-side cropping and scaling, we can use
 * default g_crop and cropcap from soc_camera.c
 */
static int mx3_camera_set_crop(struct soc_camera_device *icd,
                   const struct v4l2_crop *a)
{
    struct v4l2_crop a_writable = *a;
    struct v4l2_rect *rect = &a_writable.c;
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx3_camera_dev *mx3_cam = ici->priv;
    struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
    struct v4l2_mbus_framefmt mf;
    int ret;

    soc_camera_limit_side(&rect->left, &rect->width, 0, 2, 4096);
    soc_camera_limit_side(&rect->top, &rect->height, 0, 2, 4096);

    ret = v4l2_subdev_call(sd, video, s_crop, a);
    if (ret < 0)
        return ret;

    /* The capture device might have changed its output sizes */
    ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
    if (ret < 0)
        return ret;

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

    if (mf.width & 7) {
        /* Ouch! We can only handle 8-byte aligned width... */
        stride_align(&mf.width);
        ret = v4l2_subdev_call(sd, video, s_mbus_fmt, &mf);
        if (ret < 0)
            return ret;
    }

    if (mf.width != icd->user_width || mf.height != icd->user_height)
        configure_geometry(mx3_cam, mf.width, mf.height,
                   icd->current_fmt->host_fmt);

    dev_dbg(icd->parent, "Sensor cropped %dx%d\n",
        mf.width, mf.height);

    icd->user_width     = mf.width;
    icd->user_height    = mf.height;

    return ret;
}

static int mx3_camera_set_fmt(struct soc_camera_device *icd,
                  struct v4l2_format *f)
{
    struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
    struct mx3_camera_dev *mx3_cam = 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;
    }

    stride_align(&pix->width);
    dev_dbg(icd->parent, "Set format %dx%d\n", pix->width, pix->height);

    /*
     * Might have to perform a complete interface initialisation like in
     * ipu_csi_init_interface() in mxc_v4l2_s_param(). Also consider
     * mxc_v4l2_s_fmt()
     */

    configure_geometry(mx3_cam, pix->width, pix->height, xlate->host_fmt);

    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;

    if (!mx3_cam->idmac_channel[0]) {
        ret = acquire_dma_channel(mx3_cam);
        if (ret < 0)
            return ret;
    }

    pix->width      = mf.width;
    pix->height     = mf.height;
    pix->field      = mf.field;
    mx3_cam->field      = mf.field;
    pix->colorspace     = mf.colorspace;
    icd->current_fmt    = xlate;

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

    return ret;
}

static int mx3_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 MX3 hardware capabilities */
    if (pix->height > 4096)
        pix->height = 4096;
    if (pix->width > 4096)
        pix->width = 4096;

    /* 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 int mx3_camera_reqbufs(struct soc_camera_device *icd,
                  struct v4l2_requestbuffers *p)
{
    return 0;
}

static unsigned int mx3_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 mx3_camera_querycap(struct soc_camera_host *ici,
                   struct v4l2_capability *cap)
{
    /* cap->name is set by the firendly caller:-> */
    strlcpy(cap->card, "i.MX3x Camera", sizeof(cap->card));
    cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;

    return 0;
}

static int mx3_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 mx3_camera_dev *mx3_cam = ici->priv;
    struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
    u32 pixfmt = icd->current_fmt->host_fmt->fourcc;
    unsigned long bus_flags, common_flags;
    u32 dw, sens_conf;
    const struct soc_mbus_pixelfmt *fmt;
    int buswidth;
    int ret;
    const struct soc_camera_format_xlate *xlate;
    struct device *dev = icd->parent;

    fmt = soc_mbus_get_fmtdesc(icd->current_fmt->code);
    if (!fmt)
        return -EINVAL;

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

    buswidth = fmt->bits_per_sample;
    ret = test_platform_param(mx3_cam, buswidth, &bus_flags);

    dev_dbg(dev, "requested bus width %d bit: %d\n", buswidth, ret);

    if (ret < 0)
        return ret;

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

    dev_dbg(dev, "Flags cam: 0x%x host: 0x%lx common: 0x%lx\n",
        cfg.flags, bus_flags, common_flags);

    /* Make choices, based on platform preferences */
    if ((common_flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH) &&
        (common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)) {
        if (mx3_cam->platform_flags & MX3_CAMERA_HSP)
            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 (mx3_cam->platform_flags & MX3_CAMERA_VSP)
            common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_HIGH;
        else
            common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_LOW;
    }

    if ((common_flags & V4L2_MBUS_DATA_ACTIVE_HIGH) &&
        (common_flags & V4L2_MBUS_DATA_ACTIVE_LOW)) {
        if (mx3_cam->platform_flags & MX3_CAMERA_DP)
            common_flags &= ~V4L2_MBUS_DATA_ACTIVE_HIGH;
        else
            common_flags &= ~V4L2_MBUS_DATA_ACTIVE_LOW;
    }

    if ((common_flags & V4L2_MBUS_PCLK_SAMPLE_RISING) &&
        (common_flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)) {
        if (mx3_cam->platform_flags & MX3_CAMERA_PCP)
            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(dev, "camera s_mbus_config(0x%lx) returned %d\n",
            common_flags, ret);
        return ret;
    }

    /*
     * So far only gated clock mode is supported. Add a line
     *  (3 << CSI_SENS_CONF_SENS_PRTCL_SHIFT) |
     * below and select the required mode when supporting other
     * synchronisation protocols.
     */
    sens_conf = csi_reg_read(mx3_cam, CSI_SENS_CONF) &
        ~((1 << CSI_SENS_CONF_VSYNC_POL_SHIFT) |
          (1 << CSI_SENS_CONF_HSYNC_POL_SHIFT) |
          (1 << CSI_SENS_CONF_DATA_POL_SHIFT) |
          (1 << CSI_SENS_CONF_PIX_CLK_POL_SHIFT) |
          (3 << CSI_SENS_CONF_DATA_FMT_SHIFT) |
          (3 << CSI_SENS_CONF_DATA_WIDTH_SHIFT));

    /* TODO: Support RGB and YUV formats */

    /* This has been set in mx3_camera_activate(), but we clear it above */
    sens_conf |= CSI_SENS_CONF_DATA_FMT_BAYER;

    if (common_flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
        sens_conf |= 1 << CSI_SENS_CONF_PIX_CLK_POL_SHIFT;
    if (common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)
        sens_conf |= 1 << CSI_SENS_CONF_HSYNC_POL_SHIFT;
    if (common_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
        sens_conf |= 1 << CSI_SENS_CONF_VSYNC_POL_SHIFT;
    if (common_flags & V4L2_MBUS_DATA_ACTIVE_LOW)
        sens_conf |= 1 << CSI_SENS_CONF_DATA_POL_SHIFT;

    /* Just do what we're asked to do */
    switch (xlate->host_fmt->bits_per_sample) {
    case 4:
        dw = 0 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
        break;
    case 8:
        dw = 1 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
        break;
    case 10:
        dw = 2 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
        break;
    default:
        /*
         * Actually it can only be 15 now, default is just to silence
         * compiler warnings
         */
    case 15:
        dw = 3 << CSI_SENS_CONF_DATA_WIDTH_SHIFT;
    }

    csi_reg_write(mx3_cam, sens_conf | dw, CSI_SENS_CONF);

    dev_dbg(dev, "Set SENS_CONF to %x\n", sens_conf | dw);

    return 0;
}

static struct soc_camera_host_ops mx3_soc_camera_host_ops = {
    .owner      = THIS_MODULE,
    .add        = mx3_camera_add_device,
    .remove     = mx3_camera_remove_device,
    .set_crop   = mx3_camera_set_crop,
    .set_fmt    = mx3_camera_set_fmt,
    .try_fmt    = mx3_camera_try_fmt,
    .get_formats    = mx3_camera_get_formats,
    .init_videobuf2 = mx3_camera_init_videobuf,
    .reqbufs    = mx3_camera_reqbufs,
    .poll       = mx3_camera_poll,
    .querycap   = mx3_camera_querycap,
    .set_bus_param  = mx3_camera_set_bus_param,
};

static int __devinit mx3_camera_probe(struct platform_device *pdev)
{
    struct mx3_camera_dev *mx3_cam;
    struct resource *res;
    void __iomem *base;
    int err = 0;
    struct soc_camera_host *soc_host;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        err = -ENODEV;
        goto egetres;
    }

    mx3_cam = vzalloc(sizeof(*mx3_cam));
    if (!mx3_cam) {
        dev_err(&pdev->dev, "Could not allocate mx3 camera object\n");
        err = -ENOMEM;
        goto ealloc;
    }

    mx3_cam->clk = clk_get(&pdev->dev, NULL);
    if (IS_ERR(mx3_cam->clk)) {
        err = PTR_ERR(mx3_cam->clk);
        goto eclkget;
    }

    mx3_cam->pdata = pdev->dev.platform_data;
    mx3_cam->platform_flags = mx3_cam->pdata->flags;
    if (!(mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_MASK)) {
        /*
         * Platform hasn't set available data widths. This is bad.
         * Warn and use a default.
         */
        dev_warn(&pdev->dev, "WARNING! Platform hasn't set available "
             "data widths, using default 8 bit\n");
        mx3_cam->platform_flags |= MX3_CAMERA_DATAWIDTH_8;
    }
    if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_4)
        mx3_cam->width_flags = 1 << 3;
    if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_8)
        mx3_cam->width_flags |= 1 << 7;
    if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_10)
        mx3_cam->width_flags |= 1 << 9;
    if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_15)
        mx3_cam->width_flags |= 1 << 14;

    mx3_cam->mclk = mx3_cam->pdata->mclk_10khz * 10000;
    if (!mx3_cam->mclk) {
        dev_warn(&pdev->dev,
             "mclk_10khz == 0! Please, fix your platform data. "
             "Using default 20MHz\n");
        mx3_cam->mclk = 20000000;
    }

    /* list of video-buffers */
    INIT_LIST_HEAD(&mx3_cam->capture);
    spin_lock_init(&mx3_cam->lock);

    base = ioremap(res->start, resource_size(res));
    if (!base) {
        pr_err("Couldn't map %x@%x\n", resource_size(res), res->start);
        err = -ENOMEM;
        goto eioremap;
    }

    mx3_cam->base   = base;

    soc_host        = &mx3_cam->soc_host;
    soc_host->drv_name  = MX3_CAM_DRV_NAME;
    soc_host->ops       = &mx3_soc_camera_host_ops;
    soc_host->priv      = mx3_cam;
    soc_host->v4l2_dev.dev  = &pdev->dev;
    soc_host->nr        = pdev->id;

    mx3_cam->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
    if (IS_ERR(mx3_cam->alloc_ctx)) {
        err = PTR_ERR(mx3_cam->alloc_ctx);
        goto eallocctx;
    }

    err = soc_camera_host_register(soc_host);
    if (err)
        goto ecamhostreg;

    /* IDMAC interface */
    dmaengine_get();

    return 0;

ecamhostreg:
    vb2_dma_contig_cleanup_ctx(mx3_cam->alloc_ctx);
eallocctx:
    iounmap(base);
eioremap:
    clk_put(mx3_cam->clk);
eclkget:
    vfree(mx3_cam);
ealloc:
egetres:
    return err;
}

static int __devexit mx3_camera_remove(struct platform_device *pdev)
{
    struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
    struct mx3_camera_dev *mx3_cam = container_of(soc_host,
                    struct mx3_camera_dev, soc_host);

    clk_put(mx3_cam->clk);

    soc_camera_host_unregister(soc_host);

    iounmap(mx3_cam->base);

    /*
     * The channel has either not been allocated,
     * or should have been released
     */
    if (WARN_ON(mx3_cam->idmac_channel[0]))
        dma_release_channel(&mx3_cam->idmac_channel[0]->dma_chan);

    vb2_dma_contig_cleanup_ctx(mx3_cam->alloc_ctx);

    vfree(mx3_cam);

    dmaengine_put();

    return 0;
}

static struct platform_driver mx3_camera_driver = {
    .driver     = {
        .name   = MX3_CAM_DRV_NAME,
    },
    .probe      = mx3_camera_probe,
    .remove     = __devexit_p(mx3_camera_remove),
};

module_platform_driver(mx3_camera_driver);

MODULE_DESCRIPTION("i.MX3x SoC Camera Host driver");
MODULE_AUTHOR("Guennadi Liakhovetski <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("0.2.3");
MODULE_ALIAS("platform:" MX3_CAM_DRV_NAME);