Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6

[mirror_ubuntu-focal-kernel.git] / drivers / media / video / mx3_camera.c

/*
 * V4L2 Driver for i.MX3x camera host
 *
 * Copyright (C) 2008
 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
 *
 * 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/version.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/videobuf-dma-contig.h>
#include <media/soc_camera.h>
#include <media/soc_mediabus.h>

#include <mach/ipu.h>
#include <mach/mx3_camera.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 videobuf_buffer                  vb;
        enum v4l2_mbus_pixelcode                code;

        /* 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 camera (CSI) object
 * @dev:                camera device, to which the coherent buffer is attached
 * @icd:                currently attached camera sensor
 * @clk:                pointer to clock
 * @base:               remapped register base address
 * @pdata:              platform data
 * @platform_flags:     platform flags
 * @mclk:               master clock frequency in Hz
 * @capture:            list of capture videobuffers
 * @lock:               protects video buffer lists
 * @active:             active video buffer
 * @idmac_channel:      array of pointers to IPU DMAC DMA channels
 * @soc_host:           embedded soc_host object
 */
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;

        struct list_head        capture;
        spinlock_t              lock;           /* Protects video buffer lists */
        struct mx3_camera_buffer *active;

        /* 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);
}

/* 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;
        struct videobuf_buffer *vb;

        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) {
                vb = &mx3_cam->active->vb;

                list_del_init(&vb->queue);
                vb->state = VIDEOBUF_DONE;
                do_gettimeofday(&vb->ts);
                vb->field_count++;
                wake_up(&vb->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, vb.queue);
        mx3_cam->active->vb.state = VIDEOBUF_ACTIVE;
        spin_unlock(&mx3_cam->lock);
}

static void free_buffer(struct videobuf_queue *vq, struct mx3_camera_buffer *buf)
{
        struct soc_camera_device *icd = vq->priv_data;
        struct videobuf_buffer *vb = &buf->vb;
        struct dma_async_tx_descriptor *txd = buf->txd;
        struct idmac_channel *ichan;

        BUG_ON(in_interrupt());

        dev_dbg(icd->dev.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);
        if (txd) {
                ichan = to_idmac_chan(txd->chan);
                async_tx_ack(txd);
        }
        videobuf_dma_contig_free(vq, vb);
        buf->txd = NULL;

        vb->state = VIDEOBUF_NEEDS_INIT;
}

/*
 * Videobuf operations
 */

/*
 * Calculate the __buffer__ (not data) size and number of buffers.
 * Called with .vb_lock held
 */
static int mx3_videobuf_setup(struct videobuf_queue *vq, unsigned int *count,
                              unsigned int *size)
{
        struct soc_camera_device *icd = vq->priv_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
                                                icd->current_fmt->host_fmt);

        if (bytes_per_line < 0)
                return bytes_per_line;

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

        *size = bytes_per_line * icd->user_height;

        if (!*count)
                *count = 32;

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

        return 0;
}

/* Called with .vb_lock held */
static int mx3_videobuf_prepare(struct videobuf_queue *vq,
                struct videobuf_buffer *vb, enum v4l2_field field)
{
        struct soc_camera_device *icd = vq->priv_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        struct mx3_camera_buffer *buf =
                container_of(vb, struct mx3_camera_buffer, vb);
        size_t new_size;
        int ret;
        int bytes_per_line = soc_mbus_bytes_per_line(icd->user_width,
                                                icd->current_fmt->host_fmt);

        if (bytes_per_line < 0)
                return bytes_per_line;

        new_size = bytes_per_line * icd->user_height;

        /*
         * I think, in buf_prepare you only have to protect global data,
         * the actual buffer is yours
         */

        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;
                if (vb->state != VIDEOBUF_NEEDS_INIT)
                        free_buffer(vq, buf);
        }

        if (vb->baddr && vb->bsize < new_size) {
                /* User provided buffer, but it is too small */
                ret = -ENOMEM;
                goto out;
        }

        if (vb->state == VIDEOBUF_NEEDS_INIT) {
                struct idmac_channel *ichan = mx3_cam->idmac_channel[0];
                struct scatterlist *sg = &buf->sg;

                /*
                 * The total size of video-buffers that will be allocated / mapped.
                 * *size that we calculated in videobuf_setup gets assigned to
                 * vb->bsize, and now we use the same calculation to get vb->size.
                 */
                vb->size = new_size;

                /* This actually (allocates and) maps buffers */
                ret = videobuf_iolock(vq, vb, NULL);
                if (ret)
                        goto fail;

                /*
                 * We will have to configure the IDMAC channel. It has two slots
                 * for DMA buffers, we shall enter the first two buffers there,
                 * and then submit new buffers in DMA-ready interrupts
                 */
                sg_init_table(sg, 1);
                sg_dma_address(sg)      = videobuf_to_dma_contig(vb);
                sg_dma_len(sg)          = vb->size;

                buf->txd = ichan->dma_chan.device->device_prep_slave_sg(
                        &ichan->dma_chan, sg, 1, DMA_FROM_DEVICE,
                        DMA_PREP_INTERRUPT);
                if (!buf->txd) {
                        ret = -EIO;
                        goto fail;
                }

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

                vb->state = VIDEOBUF_PREPARED;
        }

        return 0;

fail:
        free_buffer(vq, buf);
out:
        return ret;
}

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_RGB565:
                return IPU_PIX_FMT_RGB565;
        case V4L2_PIX_FMT_RGB24:
                return IPU_PIX_FMT_RGB24;
        case V4L2_PIX_FMT_RGB332:
                return IPU_PIX_FMT_RGB332;
        case V4L2_PIX_FMT_YUV422P:
                return IPU_PIX_FMT_YVU422P;
        default:
                return IPU_PIX_FMT_GENERIC;
        }
}

/*
 * Called with .vb_lock mutex held and
 * under spinlock_irqsave(&mx3_cam->lock, ...)
 */
static void mx3_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->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        struct mx3_camera_buffer *buf =
                container_of(vb, struct mx3_camera_buffer, vb);
        struct dma_async_tx_descriptor *txd = buf->txd;
        struct idmac_channel *ichan = to_idmac_chan(txd->chan);
        struct idmac_video_param *video = &ichan->params.video;
        dma_cookie_t cookie;
        u32 fourcc = icd->current_fmt->host_fmt->fourcc;

        BUG_ON(!irqs_disabled());

        /* This is the configuration of one sg-element */
        video->out_pixel_fmt    = fourcc_to_ipu_pix(fourcc);
        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 */
        memset((void *)vb->baddr, 0xaa, vb->bsize);
#endif

        list_add_tail(&vb->queue, &mx3_cam->capture);

        if (!mx3_cam->active) {
                mx3_cam->active = buf;
                vb->state = VIDEOBUF_ACTIVE;
        } else {
                vb->state = VIDEOBUF_QUEUED;
        }

        spin_unlock_irq(&mx3_cam->lock);

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

        spin_lock_irq(&mx3_cam->lock);

        if (cookie >= 0)
                return;

        /* Submit error */
        vb->state = VIDEOBUF_PREPARED;

        list_del_init(&vb->queue);

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

/* Called with .vb_lock held */
static void mx3_videobuf_release(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->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        struct mx3_camera_buffer *buf =
                container_of(vb, struct mx3_camera_buffer, vb);
        unsigned long flags;

        dev_dbg(icd->dev.parent,
                "Release%s DMA 0x%08x (state %d), queue %sempty\n",
                mx3_cam->active == buf ? " active" : "", sg_dma_address(&buf->sg),
                vb->state, list_empty(&vb->queue) ? "" : "not ");
        spin_lock_irqsave(&mx3_cam->lock, flags);
        if ((vb->state == VIDEOBUF_ACTIVE || vb->state == VIDEOBUF_QUEUED) &&
            !list_empty(&vb->queue)) {
                vb->state = VIDEOBUF_ERROR;

                list_del_init(&vb->queue);
                if (mx3_cam->active == buf)
                        mx3_cam->active = NULL;
        }
        spin_unlock_irqrestore(&mx3_cam->lock, flags);
        free_buffer(vq, buf);
}

static struct videobuf_queue_ops mx3_videobuf_ops = {
        .buf_setup      = mx3_videobuf_setup,
        .buf_prepare    = mx3_videobuf_prepare,
        .buf_queue      = mx3_videobuf_queue,
        .buf_release    = mx3_videobuf_release,
};

static void mx3_camera_init_videobuf(struct videobuf_queue *q,
                                     struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;

        videobuf_queue_dma_contig_init(q, &mx3_videobuf_ops, icd->dev.parent,
                                       &mx3_cam->lock,
                                       V4L2_BUF_TYPE_VIDEO_CAPTURE,
                                       V4L2_FIELD_NONE,
                                       sizeof(struct mx3_camera_buffer), icd,
                                       NULL);
}

/* 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_enable(mx3_cam->clk);
        rate = clk_round_rate(mx3_cam->clk, mx3_cam->mclk);
        dev_dbg(icd->dev.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->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;

        if (mx3_cam->icd)
                return -EBUSY;

        mx3_camera_activate(mx3_cam, icd);

        mx3_cam->icd = icd;

        dev_info(icd->dev.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->dev.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(mx3_cam->clk);

        mx3_cam->icd = NULL;

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

static bool channel_change_requested(struct soc_camera_device *icd,
                                     struct v4l2_rect *rect)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        struct idmac_channel *ichan = mx3_cam->idmac_channel[0];

        /* Do buffers have to be re-allocated or channel re-configured? */
        return ichan && rect->width * rect->height >
                icd->user_width * icd->user_height;
}

static int test_platform_param(struct mx3_camera_dev *mx3_cam,
                               unsigned char buswidth, unsigned long *flags)
{
        /*
         * 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 = SOCAM_MASTER |
                SOCAM_HSYNC_ACTIVE_HIGH |
                SOCAM_HSYNC_ACTIVE_LOW |
                SOCAM_VSYNC_ACTIVE_HIGH |
                SOCAM_VSYNC_ACTIVE_LOW |
                SOCAM_PCLK_SAMPLE_RISING |
                SOCAM_PCLK_SAMPLE_FALLING |
                SOCAM_DATA_ACTIVE_HIGH |
                SOCAM_DATA_ACTIVE_LOW;

        /*
         * If requested data width is supported by the platform, use it or any
         * possible lower value - i.MX31 is smart enough to schift bits
         */
        if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_15)
                *flags |= SOCAM_DATAWIDTH_15 | SOCAM_DATAWIDTH_10 |
                        SOCAM_DATAWIDTH_8 | SOCAM_DATAWIDTH_4;
        else if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_10)
                *flags |= SOCAM_DATAWIDTH_10 | SOCAM_DATAWIDTH_8 |
                        SOCAM_DATAWIDTH_4;
        else if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_8)
                *flags |= SOCAM_DATAWIDTH_8 | SOCAM_DATAWIDTH_4;
        else if (mx3_cam->platform_flags & MX3_CAMERA_DATAWIDTH_4)
                *flags |= SOCAM_DATAWIDTH_4;

        switch (buswidth) {
        case 15:
                if (!(*flags & SOCAM_DATAWIDTH_15))
                        return -EINVAL;
                break;
        case 10:
                if (!(*flags & SOCAM_DATAWIDTH_10))
                        return -EINVAL;
                break;
        case 8:
                if (!(*flags & SOCAM_DATAWIDTH_8))
                        return -EINVAL;
                break;
        case 4:
                if (!(*flags & SOCAM_DATAWIDTH_4))
                        return -EINVAL;
                break;
        default:
                dev_warn(mx3_cam->soc_host.v4l2_dev.dev,
                         "Unsupported bus width %d\n", buswidth);
                return -EINVAL;
        }

        return 0;
}

static int mx3_camera_try_bus_param(struct soc_camera_device *icd,
                                    const unsigned int depth)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        unsigned long bus_flags, camera_flags;
        int ret = test_platform_param(mx3_cam, depth, &bus_flags);

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

        if (ret < 0)
                return ret;

        camera_flags = icd->ops->query_bus_param(icd);

        ret = soc_camera_bus_param_compatible(camera_flags, bus_flags);
        if (ret < 0)
                dev_warn(icd->dev.parent,
                         "Flags incompatible: camera %lx, host %lx\n",
                         camera_flags, bus_flags);

        return ret;
}

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

        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,
        }, {
                .fourcc                 = V4L2_PIX_FMT_GREY,
                .name                   = "Monochrome 8 bit",
                .bits_per_sample        = 8,
                .packing                = SOC_MBUS_PACKING_NONE,
                .order                  = SOC_MBUS_ORDER_LE,
        },
};

/* 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->dev.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_err(icd->dev.parent,
                        "Invalid 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;
                xlate++;
                dev_dbg(dev, "Providing format %x in pass-through mode\n",
                        xlate->host_fmt->fourcc);
        }

        return formats;
}

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

        /* 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};

        if (*ichan) {
                struct videobuf_buffer *vb, *_vb;
                dma_release_channel(&(*ichan)->dma_chan);
                *ichan = NULL;
                mx3_cam->active = NULL;
                list_for_each_entry_safe(vb, _vb, &mx3_cam->capture, queue) {
                        list_del_init(&vb->queue);
                        vb->state = VIDEOBUF_ERROR;
                        wake_up(&vb->done);
                }
        }

        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 (((*width + 7) &  ~7) < 4096)
                *width = (*width + 7) &  ~7;
        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,
                               struct v4l2_crop *a)
{
        struct v4l2_rect *rect = &a->c;
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.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  */
        ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
        if (ret < 0)
                return ret;

        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) {
                /*
                 * We now know pixel formats and can decide upon DMA-channel(s)
                 * So far only direct camera-to-memory is supported
                 */
                if (channel_change_requested(icd, rect)) {
                        ret = acquire_dma_channel(mx3_cam);
                        if (ret < 0)
                                return ret;
                }

                configure_geometry(mx3_cam, mf.width, mf.height);
        }

        dev_dbg(icd->dev.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->dev.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->dev.parent, "Format %x not found\n",
                         pix->pixelformat);
                return -EINVAL;
        }

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

        ret = acquire_dma_channel(mx3_cam);
        if (ret < 0)
                return ret;

        /*
         * 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);

        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;

        dev_dbg(icd->dev.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->dev.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;

        pix->bytesperline = soc_mbus_bytes_per_line(pix->width,
                                                    xlate->host_fmt);
        if (pix->bytesperline < 0)
                return pix->bytesperline;
        pix->sizeimage = pix->height * pix->bytesperline;

        /* 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->dev.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 videobuf_poll_stream(file, &icd->vb_vidq, 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->version = KERNEL_VERSION(0, 2, 2);
        cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;

        return 0;
}

static int mx3_camera_set_bus_param(struct soc_camera_device *icd, __u32 pixfmt)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
        struct mx3_camera_dev *mx3_cam = ici->priv;
        unsigned long bus_flags, camera_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->dev.parent;

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

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

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

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

        if (ret < 0)
                return ret;

        camera_flags = icd->ops->query_bus_param(icd);

        common_flags = soc_camera_bus_param_compatible(camera_flags, bus_flags);
        dev_dbg(dev, "Flags cam: 0x%lx host: 0x%lx common: 0x%lx\n",
                camera_flags, bus_flags, common_flags);
        if (!common_flags) {
                dev_dbg(dev, "no common flags");
                return -EINVAL;
        }

        /* Make choices, based on platform preferences */
        if ((common_flags & SOCAM_HSYNC_ACTIVE_HIGH) &&
            (common_flags & SOCAM_HSYNC_ACTIVE_LOW)) {
                if (mx3_cam->platform_flags & MX3_CAMERA_HSP)
                        common_flags &= ~SOCAM_HSYNC_ACTIVE_HIGH;
                else
                        common_flags &= ~SOCAM_HSYNC_ACTIVE_LOW;
        }

        if ((common_flags & SOCAM_VSYNC_ACTIVE_HIGH) &&
            (common_flags & SOCAM_VSYNC_ACTIVE_LOW)) {
                if (mx3_cam->platform_flags & MX3_CAMERA_VSP)
                        common_flags &= ~SOCAM_VSYNC_ACTIVE_HIGH;
                else
                        common_flags &= ~SOCAM_VSYNC_ACTIVE_LOW;
        }

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

        if ((common_flags & SOCAM_PCLK_SAMPLE_RISING) &&
            (common_flags & SOCAM_PCLK_SAMPLE_FALLING)) {
                if (mx3_cam->platform_flags & MX3_CAMERA_PCP)
                        common_flags &= ~SOCAM_PCLK_SAMPLE_RISING;
                else
                        common_flags &= ~SOCAM_PCLK_SAMPLE_FALLING;
        }

        /*
         * Make the camera work in widest common mode, we'll take care of
         * the rest
         */
        if (common_flags & SOCAM_DATAWIDTH_15)
                common_flags = (common_flags & ~SOCAM_DATAWIDTH_MASK) |
                        SOCAM_DATAWIDTH_15;
        else if (common_flags & SOCAM_DATAWIDTH_10)
                common_flags = (common_flags & ~SOCAM_DATAWIDTH_MASK) |
                        SOCAM_DATAWIDTH_10;
        else if (common_flags & SOCAM_DATAWIDTH_8)
                common_flags = (common_flags & ~SOCAM_DATAWIDTH_MASK) |
                        SOCAM_DATAWIDTH_8;
        else
                common_flags = (common_flags & ~SOCAM_DATAWIDTH_MASK) |
                        SOCAM_DATAWIDTH_4;

        ret = icd->ops->set_bus_param(icd, common_flags);
        if (ret < 0) {
                dev_dbg(dev, "camera set_bus_param(%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 & SOCAM_PCLK_SAMPLE_FALLING)
                sens_conf |= 1 << CSI_SENS_CONF_PIX_CLK_POL_SHIFT;
        if (common_flags & SOCAM_HSYNC_ACTIVE_LOW)
                sens_conf |= 1 << CSI_SENS_CONF_HSYNC_POL_SHIFT;
        if (common_flags & SOCAM_VSYNC_ACTIVE_LOW)
                sens_conf |= 1 << CSI_SENS_CONF_VSYNC_POL_SHIFT;
        if (common_flags & SOCAM_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_videobuf  = 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 = vmalloc(sizeof(*mx3_cam));
        if (!mx3_cam) {
                dev_err(&pdev->dev, "Could not allocate mx3 camera object\n");
                err = -ENOMEM;
                goto ealloc;
        }
        memset(mx3_cam, 0, sizeof(*mx3_cam));

        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_4 |
                        MX3_CAMERA_DATAWIDTH_8 | MX3_CAMERA_DATAWIDTH_10 |
                        MX3_CAMERA_DATAWIDTH_15))) {
                /*
                 * 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;
        }

        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;

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

        /* IDMAC interface */
        dmaengine_get();

        return 0;

ecamhostreg:
        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);

        vfree(mx3_cam);

        dmaengine_put();

        dev_info(&pdev->dev, "i.MX3x Camera driver unloaded\n");

        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),
};


static int __init mx3_camera_init(void)
{
        return platform_driver_register(&mx3_camera_driver);
}

static void __exit mx3_camera_exit(void)
{
        platform_driver_unregister(&mx3_camera_driver);
}

module_init(mx3_camera_init);
module_exit(mx3_camera_exit);

MODULE_DESCRIPTION("i.MX3x SoC Camera Host driver");
MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" MX3_CAM_DRV_NAME);