/*
 * V4L2 Driver for PXA camera host
 *
 * Copyright (C) 2006, Sascha Hauer, Pengutronix
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/moduleparam.h>
#include <linux/time.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dma/pxa-dma.h>

#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/videobuf-dma-sg.h>
#include <media/soc_camera.h>
#include <media/drv-intf/soc_mediabus.h>
#include <media/v4l2-of.h>

#include <linux/videodev2.h>

#include <linux/platform_data/media/camera-pxa.h>

#define PXA_CAM_VERSION "0.0.6"
#define PXA_CAM_DRV_NAME "pxa27x-camera"

/* Camera Interface */
#define CICR0           0x0000
#define CICR1           0x0004
#define CICR2           0x0008
#define CICR3           0x000C
#define CICR4           0x0010
#define CISR            0x0014
#define CIFR            0x0018
#define CITOR           0x001C
#define CIBR0           0x0028
#define CIBR1           0x0030
#define CIBR2           0x0038

#define CICR0_DMAEN     (1 << 31)       /* DMA request enable */
#define CICR0_PAR_EN    (1 << 30)       /* Parity enable */
#define CICR0_SL_CAP_EN (1 << 29)       /* Capture enable for slave mode */
#define CICR0_ENB       (1 << 28)       /* Camera interface enable */
#define CICR0_DIS       (1 << 27)       /* Camera interface disable */
#define CICR0_SIM       (0x7 << 24)     /* Sensor interface mode mask */
#define CICR0_TOM       (1 << 9)        /* Time-out mask */
#define CICR0_RDAVM     (1 << 8)        /* Receive-data-available mask */
#define CICR0_FEM       (1 << 7)        /* FIFO-empty mask */
#define CICR0_EOLM      (1 << 6)        /* End-of-line mask */
#define CICR0_PERRM     (1 << 5)        /* Parity-error mask */
#define CICR0_QDM       (1 << 4)        /* Quick-disable mask */
#define CICR0_CDM       (1 << 3)        /* Disable-done mask */
#define CICR0_SOFM      (1 << 2)        /* Start-of-frame mask */
#define CICR0_EOFM      (1 << 1)        /* End-of-frame mask */
#define CICR0_FOM       (1 << 0)        /* FIFO-overrun mask */

#define CICR1_TBIT      (1 << 31)       /* Transparency bit */
#define CICR1_RGBT_CONV (0x3 << 29)     /* RGBT conversion mask */
#define CICR1_PPL       (0x7ff << 15)   /* Pixels per line mask */
#define CICR1_RGB_CONV  (0x7 << 12)     /* RGB conversion mask */
#define CICR1_RGB_F     (1 << 11)       /* RGB format */
#define CICR1_YCBCR_F   (1 << 10)       /* YCbCr format */
#define CICR1_RGB_BPP   (0x7 << 7)      /* RGB bis per pixel mask */
#define CICR1_RAW_BPP   (0x3 << 5)      /* Raw bis per pixel mask */
#define CICR1_COLOR_SP  (0x3 << 3)      /* Color space mask */
#define CICR1_DW        (0x7 << 0)      /* Data width mask */

#define CICR2_BLW       (0xff << 24)    /* Beginning-of-line pixel clock
                                           wait count mask */
#define CICR2_ELW       (0xff << 16)    /* End-of-line pixel clock
                                           wait count mask */
#define CICR2_HSW       (0x3f << 10)    /* Horizontal sync pulse width mask */
#define CICR2_BFPW      (0x3f << 3)     /* Beginning-of-frame pixel clock
                                           wait count mask */
#define CICR2_FSW       (0x7 << 0)      /* Frame stabilization
                                           wait count mask */

#define CICR3_BFW       (0xff << 24)    /* Beginning-of-frame line clock
                                           wait count mask */
#define CICR3_EFW       (0xff << 16)    /* End-of-frame line clock
                                           wait count mask */
#define CICR3_VSW       (0x3f << 10)    /* Vertical sync pulse width mask */
#define CICR3_BFPW      (0x3f << 3)     /* Beginning-of-frame pixel clock
                                           wait count mask */
#define CICR3_LPF       (0x7ff << 0)    /* Lines per frame mask */

#define CICR4_MCLK_DLY  (0x3 << 24)     /* MCLK Data Capture Delay mask */
#define CICR4_PCLK_EN   (1 << 23)       /* Pixel clock enable */
#define CICR4_PCP       (1 << 22)       /* Pixel clock polarity */
#define CICR4_HSP       (1 << 21)       /* Horizontal sync polarity */
#define CICR4_VSP       (1 << 20)       /* Vertical sync polarity */
#define CICR4_MCLK_EN   (1 << 19)       /* MCLK enable */
#define CICR4_FR_RATE   (0x7 << 8)      /* Frame rate mask */
#define CICR4_DIV       (0xff << 0)     /* Clock divisor mask */

#define CISR_FTO        (1 << 15)       /* FIFO time-out */
#define CISR_RDAV_2     (1 << 14)       /* Channel 2 receive data available */
#define CISR_RDAV_1     (1 << 13)       /* Channel 1 receive data available */
#define CISR_RDAV_0     (1 << 12)       /* Channel 0 receive data available */
#define CISR_FEMPTY_2   (1 << 11)       /* Channel 2 FIFO empty */
#define CISR_FEMPTY_1   (1 << 10)       /* Channel 1 FIFO empty */
#define CISR_FEMPTY_0   (1 << 9)        /* Channel 0 FIFO empty */
#define CISR_EOL        (1 << 8)        /* End of line */
#define CISR_PAR_ERR    (1 << 7)        /* Parity error */
#define CISR_CQD        (1 << 6)        /* Camera interface quick disable */
#define CISR_CDD        (1 << 5)        /* Camera interface disable done */
#define CISR_SOF        (1 << 4)        /* Start of frame */
#define CISR_EOF        (1 << 3)        /* End of frame */
#define CISR_IFO_2      (1 << 2)        /* FIFO overrun for Channel 2 */
#define CISR_IFO_1      (1 << 1)        /* FIFO overrun for Channel 1 */
#define CISR_IFO_0      (1 << 0)        /* FIFO overrun for Channel 0 */

#define CIFR_FLVL2      (0x7f << 23)    /* FIFO 2 level mask */
#define CIFR_FLVL1      (0x7f << 16)    /* FIFO 1 level mask */
#define CIFR_FLVL0      (0xff << 8)     /* FIFO 0 level mask */
#define CIFR_THL_0      (0x3 << 4)      /* Threshold Level for Channel 0 FIFO */
#define CIFR_RESET_F    (1 << 3)        /* Reset input FIFOs */
#define CIFR_FEN2       (1 << 2)        /* FIFO enable for channel 2 */
#define CIFR_FEN1       (1 << 1)        /* FIFO enable for channel 1 */
#define CIFR_FEN0       (1 << 0)        /* FIFO enable for channel 0 */

#define CICR0_SIM_MP    (0 << 24)
#define CICR0_SIM_SP    (1 << 24)
#define CICR0_SIM_MS    (2 << 24)
#define CICR0_SIM_EP    (3 << 24)
#define CICR0_SIM_ES    (4 << 24)

#define CICR1_DW_VAL(x)   ((x) & CICR1_DW)          /* Data bus width */
#define CICR1_PPL_VAL(x)  (((x) << 15) & CICR1_PPL) /* Pixels per line */
#define CICR1_COLOR_SP_VAL(x)   (((x) << 3) & CICR1_COLOR_SP)   /* color space */
#define CICR1_RGB_BPP_VAL(x)    (((x) << 7) & CICR1_RGB_BPP)    /* bpp for rgb */
#define CICR1_RGBT_CONV_VAL(x)  (((x) << 29) & CICR1_RGBT_CONV) /* rgbt conv */

#define CICR2_BLW_VAL(x)  (((x) << 24) & CICR2_BLW) /* Beginning-of-line pixel clock wait count */
#define CICR2_ELW_VAL(x)  (((x) << 16) & CICR2_ELW) /* End-of-line pixel clock wait count */
#define CICR2_HSW_VAL(x)  (((x) << 10) & CICR2_HSW) /* Horizontal sync pulse width */
#define CICR2_BFPW_VAL(x) (((x) << 3) & CICR2_BFPW) /* Beginning-of-frame pixel clock wait count */
#define CICR2_FSW_VAL(x)  (((x) << 0) & CICR2_FSW)  /* Frame stabilization wait count */

#define CICR3_BFW_VAL(x)  (((x) << 24) & CICR3_BFW) /* Beginning-of-frame line clock wait count  */
#define CICR3_EFW_VAL(x)  (((x) << 16) & CICR3_EFW) /* End-of-frame line clock wait count */
#define CICR3_VSW_VAL(x)  (((x) << 11) & CICR3_VSW) /* Vertical sync pulse width */
#define CICR3_LPF_VAL(x)  (((x) << 0) & CICR3_LPF)  /* Lines per frame */

#define CICR0_IRQ_MASK (CICR0_TOM | CICR0_RDAVM | CICR0_FEM | CICR0_EOLM | \
                        CICR0_PERRM | CICR0_QDM | CICR0_CDM | CICR0_SOFM | \
                        CICR0_EOFM | CICR0_FOM)

/*
 * Structures
 */
enum pxa_camera_active_dma {
        DMA_Y = 0x1,
        DMA_U = 0x2,
        DMA_V = 0x4,
};

/* buffer for one video frame */
struct pxa_buffer {
        /* common v4l buffer stuff -- must be first */
        struct videobuf_buffer          vb;
        u32     code;
        /* our descriptor lists for Y, U and V channels */
        struct dma_async_tx_descriptor  *descs[3];
        dma_cookie_t                    cookie[3];
        struct scatterlist              *sg[3];
        int                             sg_len[3];
        int                             inwork;
        enum pxa_camera_active_dma      active_dma;
};

struct pxa_camera_dev {
        struct soc_camera_host  soc_host;
        /*
         * PXA27x is only supposed to handle one camera on its Quick Capture
         * interface. If anyone ever builds hardware to enable more than
         * one camera, they will have to modify this driver too
         */
        struct clk              *clk;

        unsigned int            irq;
        void __iomem            *base;

        int                     channels;
        struct dma_chan         *dma_chans[3];

        struct pxacamera_platform_data *pdata;
        struct resource         *res;
        unsigned long           platform_flags;
        unsigned long           ciclk;
        unsigned long           mclk;
        u32                     mclk_divisor;
        u16                     width_flags;    /* max 10 bits */

        struct list_head        capture;

        spinlock_t              lock;

        struct pxa_buffer       *active;
        struct tasklet_struct   task_eof;

        u32                     save_cicr[5];
};

struct pxa_cam {
        unsigned long flags;
};

static const char *pxa_cam_driver_description = "PXA_Camera";

static unsigned int vid_limit = 16;     /* Video memory limit, in Mb */

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

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

        *size = icd->sizeimage;

        if (0 == *count)
                *count = 32;
        if (*size * *count > vid_limit * 1024 * 1024)
                *count = (vid_limit * 1024 * 1024) / *size;

        return 0;
}

static void free_buffer(struct videobuf_queue *vq, struct pxa_buffer *buf)
{
        struct soc_camera_device *icd = vq->priv_data;
        struct videobuf_dmabuf *dma = videobuf_to_dma(&buf->vb);
        int i;

        BUG_ON(in_interrupt());

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

        for (i = 0; i < 3 && buf->descs[i]; i++) {
                dmaengine_desc_free(buf->descs[i]);
                kfree(buf->sg[i]);
                buf->descs[i] = NULL;
                buf->sg[i] = NULL;
                buf->sg_len[i] = 0;
        }
        videobuf_dma_unmap(vq->dev, dma);
        videobuf_dma_free(dma);

        buf->vb.state = VIDEOBUF_NEEDS_INIT;

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

static void pxa_camera_dma_irq(struct pxa_camera_dev *pcdev,
                               enum pxa_camera_active_dma act_dma);

static void pxa_camera_dma_irq_y(void *data)
{
        struct pxa_camera_dev *pcdev = data;

        pxa_camera_dma_irq(pcdev, DMA_Y);
}

static void pxa_camera_dma_irq_u(void *data)
{
        struct pxa_camera_dev *pcdev = data;

        pxa_camera_dma_irq(pcdev, DMA_U);
}

static void pxa_camera_dma_irq_v(void *data)
{
        struct pxa_camera_dev *pcdev = data;

        pxa_camera_dma_irq(pcdev, DMA_V);
}

/**
 * pxa_init_dma_channel - init dma descriptors
 * @pcdev: pxa camera device
 * @buf: pxa buffer to find pxa dma channel
 * @dma: dma video buffer
 * @channel: dma channel (0 => 'Y', 1 => 'U', 2 => 'V')
 * @cibr: camera Receive Buffer Register
 * @size: bytes to transfer
 * @offset: offset in videobuffer of the first byte to transfer
 *
 * Prepares the pxa dma descriptors to transfer one camera channel.
 *
 * Returns 0 if success or -ENOMEM if no memory is available
 */
static int pxa_init_dma_channel(struct pxa_camera_dev *pcdev,
                                struct pxa_buffer *buf,
                                struct videobuf_dmabuf *dma, int channel,
                                int cibr, int size, int offset)
{
        struct dma_chan *dma_chan = pcdev->dma_chans[channel];
        struct scatterlist *sg = buf->sg[channel];
        int sglen = buf->sg_len[channel];
        struct dma_async_tx_descriptor *tx;

        tx = dmaengine_prep_slave_sg(dma_chan, sg, sglen, DMA_DEV_TO_MEM,
                                     DMA_PREP_INTERRUPT | DMA_CTRL_REUSE);
        if (!tx) {
                dev_err(pcdev->soc_host.v4l2_dev.dev,
                        "dmaengine_prep_slave_sg failed\n");
                goto fail;
        }

        tx->callback_param = pcdev;
        switch (channel) {
        case 0:
                tx->callback = pxa_camera_dma_irq_y;
                break;
        case 1:
                tx->callback = pxa_camera_dma_irq_u;
                break;
        case 2:
                tx->callback = pxa_camera_dma_irq_v;
                break;
        }

        buf->descs[channel] = tx;
        return 0;
fail:
        kfree(sg);

        dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                "%s (vb=0x%p) dma_tx=%p\n",
                __func__, &buf->vb, tx);

        return -ENOMEM;
}

static void pxa_videobuf_set_actdma(struct pxa_camera_dev *pcdev,
                                    struct pxa_buffer *buf)
{
        buf->active_dma = DMA_Y;
        if (pcdev->channels == 3)
                buf->active_dma |= DMA_U | DMA_V;
}

/*
 * Please check the DMA prepared buffer structure in :
 *   Documentation/video4linux/pxa_camera.txt
 * Please check also in pxa_camera_check_link_miss() to understand why DMA chain
 * modification while DMA chain is running will work anyway.
 */
static int pxa_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->parent);
        struct pxa_camera_dev *pcdev = ici->priv;
        struct device *dev = pcdev->soc_host.v4l2_dev.dev;
        struct pxa_buffer *buf = container_of(vb, struct pxa_buffer, vb);
        int ret;
        int size_y, size_u = 0, size_v = 0;
        size_t sizes[3];

        dev_dbg(dev, "%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));

#ifdef DEBUG
        /*
         * This can be useful if you want to see if we actually fill
         * the buffer with something
         */
        memset((void *)vb->baddr, 0xaa, vb->bsize);
#endif

        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) {
                int size = vb->size;
                struct videobuf_dmabuf *dma = videobuf_to_dma(vb);

                ret = videobuf_iolock(vq, vb, NULL);
                if (ret)
                        goto out;

                if (pcdev->channels == 3) {
                        size_y = size / 2;
                        size_u = size_v = size / 4;
                } else {
                        size_y = size;
                }

                sizes[0] = size_y;
                sizes[1] = size_u;
                sizes[2] = size_v;
                ret = sg_split(dma->sglist, dma->sglen, 0, pcdev->channels,
                               sizes, buf->sg, buf->sg_len, GFP_KERNEL);
                if (ret < 0) {
                        dev_err(dev, "sg_split failed: %d\n", ret);
                        goto fail;
                }

                /* init DMA for Y channel */
                ret = pxa_init_dma_channel(pcdev, buf, dma, 0, CIBR0,
                                           size_y, 0);
                if (ret) {
                        dev_err(dev, "DMA initialization for Y/RGB failed\n");
                        goto fail;
                }

                /* init DMA for U channel */
                if (size_u)
                        ret = pxa_init_dma_channel(pcdev, buf, dma, 1, CIBR1,
                                                   size_u, size_y);
                if (ret) {
                        dev_err(dev, "DMA initialization for U failed\n");
                        goto fail;
                }

                /* init DMA for V channel */
                if (size_v)
                        ret = pxa_init_dma_channel(pcdev, buf, dma, 2, CIBR2,
                                                   size_v, size_y + size_u);
                if (ret) {
                        dev_err(dev, "DMA initialization for V failed\n");
                        goto fail;
                }

                vb->state = VIDEOBUF_PREPARED;
        }

        buf->inwork = 0;
        pxa_videobuf_set_actdma(pcdev, buf);

        return 0;

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

/**
 * pxa_dma_start_channels - start DMA channel for active buffer
 * @pcdev: pxa camera device
 *
 * Initialize DMA channels to the beginning of the active video buffer, and
 * start these channels.
 */
static void pxa_dma_start_channels(struct pxa_camera_dev *pcdev)
{
        int i;
        struct pxa_buffer *active;

        active = pcdev->active;

        for (i = 0; i < pcdev->channels; i++) {
                dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                        "%s (channel=%d)\n", __func__, i);
                dma_async_issue_pending(pcdev->dma_chans[i]);
        }
}

static void pxa_dma_stop_channels(struct pxa_camera_dev *pcdev)
{
        int i;

        for (i = 0; i < pcdev->channels; i++) {
                dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                        "%s (channel=%d)\n", __func__, i);
                dmaengine_terminate_all(pcdev->dma_chans[i]);
        }
}

static void pxa_dma_add_tail_buf(struct pxa_camera_dev *pcdev,
                                 struct pxa_buffer *buf)
{
        int i;

        for (i = 0; i < pcdev->channels; i++) {
                buf->cookie[i] = dmaengine_submit(buf->descs[i]);
                dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                        "%s (channel=%d) : submit vb=%p cookie=%d\n",
                        __func__, i, buf, buf->descs[i]->cookie);
        }
}

/**
 * pxa_camera_start_capture - start video capturing
 * @pcdev: camera device
 *
 * Launch capturing. DMA channels should not be active yet. They should get
 * activated at the end of frame interrupt, to capture only whole frames, and
 * never begin the capture of a partial frame.
 */
static void pxa_camera_start_capture(struct pxa_camera_dev *pcdev)
{
        unsigned long cicr0;

        dev_dbg(pcdev->soc_host.v4l2_dev.dev, "%s\n", __func__);
        __raw_writel(__raw_readl(pcdev->base + CISR), pcdev->base + CISR);
        /* Enable End-Of-Frame Interrupt */
        cicr0 = __raw_readl(pcdev->base + CICR0) | CICR0_ENB;
        cicr0 &= ~CICR0_EOFM;
        __raw_writel(cicr0, pcdev->base + CICR0);
}

static void pxa_camera_stop_capture(struct pxa_camera_dev *pcdev)
{
        unsigned long cicr0;

        pxa_dma_stop_channels(pcdev);

        cicr0 = __raw_readl(pcdev->base + CICR0) & ~CICR0_ENB;
        __raw_writel(cicr0, pcdev->base + CICR0);

        pcdev->active = NULL;
        dev_dbg(pcdev->soc_host.v4l2_dev.dev, "%s\n", __func__);
}

/* Called under spinlock_irqsave(&pcdev->lock, ...) */
static void pxa_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 pxa_camera_dev *pcdev = ici->priv;
        struct pxa_buffer *buf = container_of(vb, struct pxa_buffer, vb);

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

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

        vb->state = VIDEOBUF_ACTIVE;
        pxa_dma_add_tail_buf(pcdev, buf);

        if (!pcdev->active)
                pxa_camera_start_capture(pcdev);
}

static void pxa_videobuf_release(struct videobuf_queue *vq,
                                 struct videobuf_buffer *vb)
{
        struct pxa_buffer *buf = container_of(vb, struct pxa_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 pxa_camera_wakeup(struct pxa_camera_dev *pcdev,
                              struct videobuf_buffer *vb,
                              struct pxa_buffer *buf)
{
        /* _init is used to debug races, see comment in pxa_camera_reqbufs() */
        list_del_init(&vb->queue);
        vb->state = VIDEOBUF_DONE;
        v4l2_get_timestamp(&vb->ts);
        vb->field_count++;
        wake_up(&vb->done);
        dev_dbg(pcdev->soc_host.v4l2_dev.dev, "%s dequeud buffer (vb=0x%p)\n",
                __func__, vb);

        if (list_empty(&pcdev->capture)) {
                pxa_camera_stop_capture(pcdev);
                return;
        }

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

/**
 * pxa_camera_check_link_miss - check missed DMA linking
 * @pcdev: camera device
 *
 * The DMA chaining is done with DMA running. This means a tiny temporal window
 * remains, where a buffer is queued on the chain, while the chain is already
 * stopped. This means the tailed buffer would never be transferred by DMA.
 * This function restarts the capture for this corner case, where :
 *  - DADR() == DADDR_STOP
 *  - a videobuffer is queued on the pcdev->capture list
 *
 * Please check the "DMA hot chaining timeslice issue" in
 *   Documentation/video4linux/pxa_camera.txt
 *
 * Context: should only be called within the dma irq handler
 */
static void pxa_camera_check_link_miss(struct pxa_camera_dev *pcdev,
                                       dma_cookie_t last_submitted,
                                       dma_cookie_t last_issued)
{
        bool is_dma_stopped = last_submitted != last_issued;

        dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                "%s : top queued buffer=%p, is_dma_stopped=%d\n",
                __func__, pcdev->active, is_dma_stopped);

        if (pcdev->active && is_dma_stopped)
                pxa_camera_start_capture(pcdev);
}

static void pxa_camera_dma_irq(struct pxa_camera_dev *pcdev,
                               enum pxa_camera_active_dma act_dma)
{
        struct device *dev = pcdev->soc_host.v4l2_dev.dev;
        struct pxa_buffer *buf, *last_buf;
        unsigned long flags;
        u32 camera_status, overrun;
        int chan;
        struct videobuf_buffer *vb;
        enum dma_status last_status;
        dma_cookie_t last_issued;

        spin_lock_irqsave(&pcdev->lock, flags);

        camera_status = __raw_readl(pcdev->base + CISR);
        dev_dbg(dev, "camera dma irq, cisr=0x%x dma=%d\n",
                camera_status, act_dma);
        overrun = CISR_IFO_0;
        if (pcdev->channels == 3)
                overrun |= CISR_IFO_1 | CISR_IFO_2;

        /*
         * pcdev->active should not be NULL in DMA irq handler.
         *
         * But there is one corner case : if capture was stopped due to an
         * overrun of channel 1, and at that same channel 2 was completed.
         *
         * When handling the overrun in DMA irq for channel 1, we'll stop the
         * capture and restart it (and thus set pcdev->active to NULL). But the
         * DMA irq handler will already be pending for channel 2. So on entering
         * the DMA irq handler for channel 2 there will be no active buffer, yet
         * that is normal.
         */
        if (!pcdev->active)
                goto out;

        vb = &pcdev->active->vb;
        buf = container_of(vb, struct pxa_buffer, vb);
        WARN_ON(buf->inwork || list_empty(&vb->queue));

        /*
         * It's normal if the last frame creates an overrun, as there
         * are no more DMA descriptors to fetch from QCI fifos
         */
        switch (act_dma) {
        case DMA_U:
                chan = 1;
                break;
        case DMA_V:
                chan = 2;
                break;
        default:
                chan = 0;
                break;
        }
        last_buf = list_entry(pcdev->capture.prev,
                              struct pxa_buffer, vb.queue);
        last_status = dma_async_is_tx_complete(pcdev->dma_chans[chan],
                                               last_buf->cookie[chan],
                                               NULL, &last_issued);
        if (camera_status & overrun &&
            last_status != DMA_COMPLETE) {
                dev_dbg(dev, "FIFO overrun! CISR: %x\n",
                        camera_status);
                pxa_camera_stop_capture(pcdev);
                list_for_each_entry(buf, &pcdev->capture, vb.queue)
                        pxa_dma_add_tail_buf(pcdev, buf);
                pxa_camera_start_capture(pcdev);
                goto out;
        }
        buf->active_dma &= ~act_dma;
        if (!buf->active_dma) {
                pxa_camera_wakeup(pcdev, vb, buf);
                pxa_camera_check_link_miss(pcdev, last_buf->cookie[chan],
                                           last_issued);
        }

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

static struct videobuf_queue_ops pxa_videobuf_ops = {
        .buf_setup      = pxa_videobuf_setup,
        .buf_prepare    = pxa_videobuf_prepare,
        .buf_queue      = pxa_videobuf_queue,
        .buf_release    = pxa_videobuf_release,
};

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

        /*
         * We must pass NULL as dev pointer, then all pci_* dma operations
         * transform to normal dma_* ones.
         */
        videobuf_queue_sg_init(q, &pxa_videobuf_ops, NULL, &pcdev->lock,
                                V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
                                sizeof(struct pxa_buffer), icd, &ici->host_lock);
}

static u32 mclk_get_divisor(struct platform_device *pdev,
                            struct pxa_camera_dev *pcdev)
{
        unsigned long mclk = pcdev->mclk;
        struct device *dev = &pdev->dev;
        u32 div;
        unsigned long lcdclk;

        lcdclk = clk_get_rate(pcdev->clk);
        pcdev->ciclk = lcdclk;

        /* mclk <= ciclk / 4 (27.4.2) */
        if (mclk > lcdclk / 4) {
                mclk = lcdclk / 4;
                dev_warn(dev, "Limiting master clock to %lu\n", mclk);
        }

        /* We verify mclk != 0, so if anyone breaks it, here comes their Oops */
        div = (lcdclk + 2 * mclk - 1) / (2 * mclk) - 1;

        /* If we're not supplying MCLK, leave it at 0 */
        if (pcdev->platform_flags & PXA_CAMERA_MCLK_EN)
                pcdev->mclk = lcdclk / (2 * (div + 1));

        dev_dbg(dev, "LCD clock %luHz, target freq %luHz, divisor %u\n",
                lcdclk, mclk, div);

        return div;
}

static void recalculate_fifo_timeout(struct pxa_camera_dev *pcdev,
                                     unsigned long pclk)
{
        /* We want a timeout > 1 pixel time, not ">=" */
        u32 ciclk_per_pixel = pcdev->ciclk / pclk + 1;

        __raw_writel(ciclk_per_pixel, pcdev->base + CITOR);
}

static void pxa_camera_activate(struct pxa_camera_dev *pcdev)
{
        u32 cicr4 = 0;

        /* disable all interrupts */
        __raw_writel(0x3ff, pcdev->base + CICR0);

        if (pcdev->platform_flags & PXA_CAMERA_PCLK_EN)
                cicr4 |= CICR4_PCLK_EN;
        if (pcdev->platform_flags & PXA_CAMERA_MCLK_EN)
                cicr4 |= CICR4_MCLK_EN;
        if (pcdev->platform_flags & PXA_CAMERA_PCP)
                cicr4 |= CICR4_PCP;
        if (pcdev->platform_flags & PXA_CAMERA_HSP)
                cicr4 |= CICR4_HSP;
        if (pcdev->platform_flags & PXA_CAMERA_VSP)
                cicr4 |= CICR4_VSP;

        __raw_writel(pcdev->mclk_divisor | cicr4, pcdev->base + CICR4);

        if (pcdev->platform_flags & PXA_CAMERA_MCLK_EN)
                /* Initialise the timeout under the assumption pclk = mclk */
                recalculate_fifo_timeout(pcdev, pcdev->mclk);
        else
                /* "Safe default" - 13MHz */
                recalculate_fifo_timeout(pcdev, 13000000);

        clk_prepare_enable(pcdev->clk);
}

static void pxa_camera_deactivate(struct pxa_camera_dev *pcdev)
{
        clk_disable_unprepare(pcdev->clk);
}

static void pxa_camera_eof(unsigned long arg)
{
        struct pxa_camera_dev *pcdev = (struct pxa_camera_dev *)arg;
        unsigned long cifr;
        struct pxa_buffer *buf;
        struct videobuf_buffer *vb;

        dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                "Camera interrupt status 0x%x\n",
                __raw_readl(pcdev->base + CISR));

        /* Reset the FIFOs */
        cifr = __raw_readl(pcdev->base + CIFR) | CIFR_RESET_F;
        __raw_writel(cifr, pcdev->base + CIFR);

        pcdev->active = list_first_entry(&pcdev->capture,
                                         struct pxa_buffer, vb.queue);
        vb = &pcdev->active->vb;
        buf = container_of(vb, struct pxa_buffer, vb);
        pxa_videobuf_set_actdma(pcdev, buf);

        pxa_dma_start_channels(pcdev);
}

static irqreturn_t pxa_camera_irq(int irq, void *data)
{
        struct pxa_camera_dev *pcdev = data;
        unsigned long status, cicr0;

        status = __raw_readl(pcdev->base + CISR);
        dev_dbg(pcdev->soc_host.v4l2_dev.dev,
                "Camera interrupt status 0x%lx\n", status);

        if (!status)
                return IRQ_NONE;

        __raw_writel(status, pcdev->base + CISR);

        if (status & CISR_EOF) {
                cicr0 = __raw_readl(pcdev->base + CICR0) | CICR0_EOFM;
                __raw_writel(cicr0, pcdev->base + CICR0);
                tasklet_schedule(&pcdev->task_eof);
        }

        return IRQ_HANDLED;
}

static int pxa_camera_add_device(struct soc_camera_device *icd)
{
        dev_info(icd->parent, "PXA Camera driver attached to camera %d\n",
                 icd->devnum);

        return 0;
}

static void pxa_camera_remove_device(struct soc_camera_device *icd)
{
        dev_info(icd->parent, "PXA Camera driver detached from camera %d\n",
                 icd->devnum);
}

/*
 * The following two functions absolutely depend on the fact, that
 * there can be only one camera on PXA quick capture interface
 * Called with .host_lock held
 */
static int pxa_camera_clock_start(struct soc_camera_host *ici)
{
        struct pxa_camera_dev *pcdev = ici->priv;

        pxa_camera_activate(pcdev);

        return 0;
}

/* Called with .host_lock held */
static void pxa_camera_clock_stop(struct soc_camera_host *ici)
{
        struct pxa_camera_dev *pcdev = ici->priv;

        /* disable capture, disable interrupts */
        __raw_writel(0x3ff, pcdev->base + CICR0);

        /* Stop DMA engine */
        pxa_dma_stop_channels(pcdev);
        pxa_camera_deactivate(pcdev);
}

static int test_platform_param(struct pxa_camera_dev *pcdev,
                               unsigned char buswidth, unsigned long *flags)
{
        /*
         * Platform specified synchronization and pixel clock polarities are
         * only a recommendation and are only used during probing. The PXA270
         * quick capture interface supports both.
         */
        *flags = (pcdev->platform_flags & PXA_CAMERA_MASTER ?
                  V4L2_MBUS_MASTER : V4L2_MBUS_SLAVE) |
                V4L2_MBUS_HSYNC_ACTIVE_HIGH |
                V4L2_MBUS_HSYNC_ACTIVE_LOW |
                V4L2_MBUS_VSYNC_ACTIVE_HIGH |
                V4L2_MBUS_VSYNC_ACTIVE_LOW |
                V4L2_MBUS_DATA_ACTIVE_HIGH |
                V4L2_MBUS_PCLK_SAMPLE_RISING |
                V4L2_MBUS_PCLK_SAMPLE_FALLING;

        /* If requested data width is supported by the platform, use it */
        if ((1 << (buswidth - 1)) & pcdev->width_flags)
                return 0;

        return -EINVAL;
}

static void pxa_camera_setup_cicr(struct soc_camera_device *icd,
                                  unsigned long flags, __u32 pixfmt)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct pxa_camera_dev *pcdev = ici->priv;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        unsigned long dw, bpp;
        u32 cicr0, cicr1, cicr2, cicr3, cicr4 = 0, y_skip_top;
        int ret = v4l2_subdev_call(sd, sensor, g_skip_top_lines, &y_skip_top);

        if (ret < 0)
                y_skip_top = 0;

        /*
         * Datawidth is now guaranteed to be equal to one of the three values.
         * We fix bit-per-pixel equal to data-width...
         */
        switch (icd->current_fmt->host_fmt->bits_per_sample) {
        case 10:
                dw = 4;
                bpp = 0x40;
                break;
        case 9:
                dw = 3;
                bpp = 0x20;
                break;
        default:
                /*
                 * Actually it can only be 8 now,
                 * default is just to silence compiler warnings

                 */
        case 8:
                dw = 2;
                bpp = 0;
        }

        if (pcdev->platform_flags & PXA_CAMERA_PCLK_EN)
                cicr4 |= CICR4_PCLK_EN;
        if (pcdev->platform_flags & PXA_CAMERA_MCLK_EN)
                cicr4 |= CICR4_MCLK_EN;
        if (flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
                cicr4 |= CICR4_PCP;
        if (flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)
                cicr4 |= CICR4_HSP;
        if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)
                cicr4 |= CICR4_VSP;

        cicr0 = __raw_readl(pcdev->base + CICR0);
        if (cicr0 & CICR0_ENB)
                __raw_writel(cicr0 & ~CICR0_ENB, pcdev->base + CICR0);

        cicr1 = CICR1_PPL_VAL(icd->user_width - 1) | bpp | dw;

        switch (pixfmt) {
        case V4L2_PIX_FMT_YUV422P:
                pcdev->channels = 3;
                cicr1 |= CICR1_YCBCR_F;
                /*
                 * Normally, pxa bus wants as input UYVY format. We allow all
                 * reorderings of the YUV422 format, as no processing is done,
                 * and the YUV stream is just passed through without any
                 * transformation. Note that UYVY is the only format that
                 * should be used if pxa framebuffer Overlay2 is used.
                 */
        case V4L2_PIX_FMT_UYVY:
        case V4L2_PIX_FMT_VYUY:
        case V4L2_PIX_FMT_YUYV:
        case V4L2_PIX_FMT_YVYU:
                cicr1 |= CICR1_COLOR_SP_VAL(2);
                break;
        case V4L2_PIX_FMT_RGB555:
                cicr1 |= CICR1_RGB_BPP_VAL(1) | CICR1_RGBT_CONV_VAL(2) |
                        CICR1_TBIT | CICR1_COLOR_SP_VAL(1);
                break;
        case V4L2_PIX_FMT_RGB565:
                cicr1 |= CICR1_COLOR_SP_VAL(1) | CICR1_RGB_BPP_VAL(2);
                break;
        }

        cicr2 = 0;
        cicr3 = CICR3_LPF_VAL(icd->user_height - 1) |
                CICR3_BFW_VAL(min((u32)255, y_skip_top));
        cicr4 |= pcdev->mclk_divisor;

        __raw_writel(cicr1, pcdev->base + CICR1);
        __raw_writel(cicr2, pcdev->base + CICR2);
        __raw_writel(cicr3, pcdev->base + CICR3);
        __raw_writel(cicr4, pcdev->base + CICR4);

        /* CIF interrupts are not used, only DMA */
        cicr0 = (cicr0 & CICR0_ENB) | (pcdev->platform_flags & PXA_CAMERA_MASTER ?
                CICR0_SIM_MP : (CICR0_SL_CAP_EN | CICR0_SIM_SP));
        cicr0 |= CICR0_DMAEN | CICR0_IRQ_MASK;
        __raw_writel(cicr0, pcdev->base + CICR0);
}

static int pxa_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 pxa_camera_dev *pcdev = 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;
        int ret;
        struct pxa_cam *cam = icd->host_priv;

        ret = test_platform_param(pcdev, icd->current_fmt->host_fmt->bits_per_sample,
                                  &bus_flags);
        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;
        }

        pcdev->channels = 1;

        /* Make choises, based on platform preferences */
        if ((common_flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH) &&
            (common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)) {
                if (pcdev->platform_flags & PXA_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 (pcdev->platform_flags & PXA_CAMERA_VSP)
                        common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_HIGH;
                else
                        common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_LOW;
        }

        if ((common_flags & V4L2_MBUS_PCLK_SAMPLE_RISING) &&
            (common_flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)) {
                if (pcdev->platform_flags & PXA_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(icd->parent, "camera s_mbus_config(0x%lx) returned %d\n",
                        common_flags, ret);
                return ret;
        }

        cam->flags = common_flags;

        pxa_camera_setup_cicr(icd, common_flags, pixfmt);

        return 0;
}

static int pxa_camera_try_bus_param(struct soc_camera_device *icd,
                                    unsigned char buswidth)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct pxa_camera_dev *pcdev = ici->priv;
        struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
        unsigned long bus_flags, common_flags;
        int ret = test_platform_param(pcdev, buswidth, &bus_flags);

        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) {
                ret = 0;
        }

        return ret;
}

static const struct soc_mbus_pixelfmt pxa_camera_formats[] = {
        {
                .fourcc                 = V4L2_PIX_FMT_YUV422P,
                .name                   = "Planar YUV422 16 bit",
                .bits_per_sample        = 8,
                .packing                = SOC_MBUS_PACKING_2X8_PADHI,
                .order                  = SOC_MBUS_ORDER_LE,
                .layout                 = SOC_MBUS_LAYOUT_PLANAR_2Y_U_V,
        },
};

/* This will be corrected as we get more formats */
static bool pxa_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 pxa_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;
        struct pxa_cam *cam;
        struct v4l2_subdev_mbus_code_enum code = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
                .index = idx,
        };
        const struct soc_mbus_pixelfmt *fmt;

        ret = v4l2_subdev_call(sd, pad, enum_mbus_code, NULL, &code);
        if (ret < 0)
                /* No more formats */
                return 0;

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

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

        if (!icd->host_priv) {
                cam = kzalloc(sizeof(*cam), GFP_KERNEL);
                if (!cam)
                        return -ENOMEM;

                icd->host_priv = cam;
        } else {
                cam = icd->host_priv;
        }

        switch (code.code) {
        case MEDIA_BUS_FMT_UYVY8_2X8:
                formats++;
                if (xlate) {
                        xlate->host_fmt = &pxa_camera_formats[0];
                        xlate->code     = code.code;
                        xlate++;
                        dev_dbg(dev, "Providing format %s using code %d\n",
                                pxa_camera_formats[0].name, code.code);
                }
        case MEDIA_BUS_FMT_VYUY8_2X8:
        case MEDIA_BUS_FMT_YUYV8_2X8:
        case MEDIA_BUS_FMT_YVYU8_2X8:
        case MEDIA_BUS_FMT_RGB565_2X8_LE:
        case MEDIA_BUS_FMT_RGB555_2X8_PADHI_LE:
                if (xlate)
                        dev_dbg(dev, "Providing format %s packed\n",
                                fmt->name);
                break;
        default:
                if (!pxa_camera_packing_supported(fmt))
                        return 0;
                if (xlate)
                        dev_dbg(dev,
                                "Providing format %s in pass-through mode\n",
                                fmt->name);
        }

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

        return formats;
}

static void pxa_camera_put_formats(struct soc_camera_device *icd)
{
        kfree(icd->host_priv);
        icd->host_priv = NULL;
}

static int pxa_camera_check_frame(u32 width, u32 height)
{
        /* limit to pxa hardware capabilities */
        return height < 32 || height > 2048 || width < 48 || width > 2048 ||
                (width & 0x01);
}

static int pxa_camera_set_crop(struct soc_camera_device *icd,
                               const struct v4l2_crop *a)
{
        const struct v4l2_rect *rect = &a->c;
        struct device *dev = icd->parent;
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct pxa_camera_dev *pcdev = ici->priv;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct soc_camera_sense sense = {
                .master_clock = pcdev->mclk,
                .pixel_clock_max = pcdev->ciclk / 4,
        };
        struct v4l2_subdev_format fmt = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        struct v4l2_mbus_framefmt *mf = &fmt.format;
        struct pxa_cam *cam = icd->host_priv;
        u32 fourcc = icd->current_fmt->host_fmt->fourcc;
        int ret;

        /* If PCLK is used to latch data from the sensor, check sense */
        if (pcdev->platform_flags & PXA_CAMERA_PCLK_EN)
                icd->sense = &sense;

        ret = v4l2_subdev_call(sd, video, s_crop, a);

        icd->sense = NULL;

        if (ret < 0) {
                dev_warn(dev, "Failed to crop to %ux%u@%u:%u\n",
                         rect->width, rect->height, rect->left, rect->top);
                return ret;
        }

        ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, &fmt);
        if (ret < 0)
                return ret;

        if (pxa_camera_check_frame(mf->width, mf->height)) {
                /*
                 * Camera cropping produced a frame beyond our capabilities.
                 * FIXME: just extract a subframe, that we can process.
                 */
                v4l_bound_align_image(&mf->width, 48, 2048, 1,
                        &mf->height, 32, 2048, 0,
                        fourcc == V4L2_PIX_FMT_YUV422P ? 4 : 0);
                ret = v4l2_subdev_call(sd, pad, set_fmt, NULL, &fmt);
                if (ret < 0)
                        return ret;

                if (pxa_camera_check_frame(mf->width, mf->height)) {
                        dev_warn(icd->parent,
                                 "Inconsistent state. Use S_FMT to repair\n");
                        return -EINVAL;
                }
        }

        if (sense.flags & SOCAM_SENSE_PCLK_CHANGED) {
                if (sense.pixel_clock > sense.pixel_clock_max) {
                        dev_err(dev,
                                "pixel clock %lu set by the camera too high!",
                                sense.pixel_clock);
                        return -EIO;
                }
                recalculate_fifo_timeout(pcdev, sense.pixel_clock);
        }

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

        pxa_camera_setup_cicr(icd, cam->flags, fourcc);

        return ret;
}

static int pxa_camera_set_fmt(struct soc_camera_device *icd,
                              struct v4l2_format *f)
{
        struct device *dev = icd->parent;
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct pxa_camera_dev *pcdev = ici->priv;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        const struct soc_camera_format_xlate *xlate = NULL;
        struct soc_camera_sense sense = {
                .master_clock = pcdev->mclk,
                .pixel_clock_max = pcdev->ciclk / 4,
        };
        struct v4l2_pix_format *pix = &f->fmt.pix;
        struct v4l2_subdev_format format = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
        };
        struct v4l2_mbus_framefmt *mf = &format.format;
        int ret;

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

        /* If PCLK is used to latch data from the sensor, check sense */
        if (pcdev->platform_flags & PXA_CAMERA_PCLK_EN)
                /* The caller holds a mutex. */
                icd->sense = &sense;

        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, pad, set_fmt, NULL, &format);

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

        icd->sense = NULL;

        if (ret < 0) {
                dev_warn(dev, "Failed to configure for format %x\n",
                         pix->pixelformat);
        } else if (pxa_camera_check_frame(mf->width, mf->height)) {
                dev_warn(dev,
                         "Camera driver produced an unsupported frame %dx%d\n",
                         mf->width, mf->height);
                ret = -EINVAL;
        } else if (sense.flags & SOCAM_SENSE_PCLK_CHANGED) {
                if (sense.pixel_clock > sense.pixel_clock_max) {
                        dev_err(dev,
                                "pixel clock %lu set by the camera too high!",
                                sense.pixel_clock);
                        return -EIO;
                }
                recalculate_fifo_timeout(pcdev, sense.pixel_clock);
        }

        if (ret < 0)
                return ret;

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

        return ret;
}

static int pxa_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_subdev_pad_config pad_cfg;
        struct v4l2_subdev_format format = {
                .which = V4L2_SUBDEV_FORMAT_TRY,
        };
        struct v4l2_mbus_framefmt *mf = &format.format;
        __u32 pixfmt = pix->pixelformat;
        int ret;

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

        /*
         * Limit to pxa hardware capabilities.  YUV422P planar format requires
         * images size to be a multiple of 16 bytes.  If not, zeros will be
         * inserted between Y and U planes, and U and V planes, which violates
         * the YUV422P standard.
         */
        v4l_bound_align_image(&pix->width, 48, 2048, 1,
                              &pix->height, 32, 2048, 0,
                              pixfmt == V4L2_PIX_FMT_YUV422P ? 4 : 0);

        /* limit to sensor capabilities */
        mf->width       = pix->width;
        mf->height      = pix->height;
        /* Only progressive video supported so far */
        mf->field       = V4L2_FIELD_NONE;
        mf->colorspace  = pix->colorspace;
        mf->code        = xlate->code;

        ret = v4l2_subdev_call(sd, pad, set_fmt, &pad_cfg, &format);
        if (ret < 0)
                return ret;

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

        switch (mf->field) {
        case V4L2_FIELD_ANY:
        case V4L2_FIELD_NONE:
                pix->field      = V4L2_FIELD_NONE;
                break;
        default:
                /* TODO: support interlaced at least in pass-through mode */
                dev_err(icd->parent, "Field type %d unsupported.\n",
                        mf->field);
                return -EINVAL;
        }

        return ret;
}

static int pxa_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 pxa_buffer *buf = container_of(icd->vb_vidq.bufs[i],
                                                      struct pxa_buffer, vb);
                buf->inwork = 0;
                INIT_LIST_HEAD(&buf->vb.queue);
        }

        return 0;
}

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

        buf = list_entry(icd->vb_vidq.stream.next, struct pxa_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 pxa_camera_querycap(struct soc_camera_host *ici,
                               struct v4l2_capability *cap)
{
        /* cap->name is set by the firendly caller:-> */
        strlcpy(cap->card, pxa_cam_driver_description, sizeof(cap->card));
        cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
        cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

        return 0;
}

static int pxa_camera_suspend(struct device *dev)
{
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct pxa_camera_dev *pcdev = ici->priv;
        int i = 0, ret = 0;

        pcdev->save_cicr[i++] = __raw_readl(pcdev->base + CICR0);
        pcdev->save_cicr[i++] = __raw_readl(pcdev->base + CICR1);
        pcdev->save_cicr[i++] = __raw_readl(pcdev->base + CICR2);
        pcdev->save_cicr[i++] = __raw_readl(pcdev->base + CICR3);
        pcdev->save_cicr[i++] = __raw_readl(pcdev->base + CICR4);

        if (pcdev->soc_host.icd) {
                struct v4l2_subdev *sd = soc_camera_to_subdev(pcdev->soc_host.icd);
                ret = v4l2_subdev_call(sd, core, s_power, 0);
                if (ret == -ENOIOCTLCMD)
                        ret = 0;
        }

        return ret;
}

static int pxa_camera_resume(struct device *dev)
{
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct pxa_camera_dev *pcdev = ici->priv;
        int i = 0, ret = 0;

        __raw_writel(pcdev->save_cicr[i++] & ~CICR0_ENB, pcdev->base + CICR0);
        __raw_writel(pcdev->save_cicr[i++], pcdev->base + CICR1);
        __raw_writel(pcdev->save_cicr[i++], pcdev->base + CICR2);
        __raw_writel(pcdev->save_cicr[i++], pcdev->base + CICR3);
        __raw_writel(pcdev->save_cicr[i++], pcdev->base + CICR4);

        if (pcdev->soc_host.icd) {
                struct v4l2_subdev *sd = soc_camera_to_subdev(pcdev->soc_host.icd);
                ret = v4l2_subdev_call(sd, core, s_power, 1);
                if (ret == -ENOIOCTLCMD)
                        ret = 0;
        }

        /* Restart frame capture if active buffer exists */
        if (!ret && pcdev->active)
                pxa_camera_start_capture(pcdev);

        return ret;
}

static struct soc_camera_host_ops pxa_soc_camera_host_ops = {
        .owner          = THIS_MODULE,
        .add            = pxa_camera_add_device,
        .remove         = pxa_camera_remove_device,
        .clock_start    = pxa_camera_clock_start,
        .clock_stop     = pxa_camera_clock_stop,
        .set_crop       = pxa_camera_set_crop,
        .get_formats    = pxa_camera_get_formats,
        .put_formats    = pxa_camera_put_formats,
        .set_fmt        = pxa_camera_set_fmt,
        .try_fmt        = pxa_camera_try_fmt,
        .init_videobuf  = pxa_camera_init_videobuf,
        .reqbufs        = pxa_camera_reqbufs,
        .poll           = pxa_camera_poll,
        .querycap       = pxa_camera_querycap,
        .set_bus_param  = pxa_camera_set_bus_param,
};

static int pxa_camera_pdata_from_dt(struct device *dev,
                                    struct pxa_camera_dev *pcdev)
{
        u32 mclk_rate;
        struct device_node *np = dev->of_node;
        struct v4l2_of_endpoint ep;
        int err = of_property_read_u32(np, "clock-frequency",
                                       &mclk_rate);
        if (!err) {
                pcdev->platform_flags |= PXA_CAMERA_MCLK_EN;
                pcdev->mclk = mclk_rate;
        }

        np = of_graph_get_next_endpoint(np, NULL);
        if (!np) {
                dev_err(dev, "could not find endpoint\n");
                return -EINVAL;
        }

        err = v4l2_of_parse_endpoint(np, &ep);
        if (err) {
                dev_err(dev, "could not parse endpoint\n");
                goto out;
        }

        switch (ep.bus.parallel.bus_width) {
        case 4:
                pcdev->platform_flags |= PXA_CAMERA_DATAWIDTH_4;
                break;
        case 5:
                pcdev->platform_flags |= PXA_CAMERA_DATAWIDTH_5;
                break;
        case 8:
                pcdev->platform_flags |= PXA_CAMERA_DATAWIDTH_8;
                break;
        case 9:
                pcdev->platform_flags |= PXA_CAMERA_DATAWIDTH_9;
                break;
        case 10:
                pcdev->platform_flags |= PXA_CAMERA_DATAWIDTH_10;
                break;
        default:
                break;
        }

        if (ep.bus.parallel.flags & V4L2_MBUS_MASTER)
                pcdev->platform_flags |= PXA_CAMERA_MASTER;
        if (ep.bus.parallel.flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
                pcdev->platform_flags |= PXA_CAMERA_HSP;
        if (ep.bus.parallel.flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
                pcdev->platform_flags |= PXA_CAMERA_VSP;
        if (ep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
                pcdev->platform_flags |= PXA_CAMERA_PCLK_EN | PXA_CAMERA_PCP;
        if (ep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
                pcdev->platform_flags |= PXA_CAMERA_PCLK_EN;

out:
        of_node_put(np);

        return err;
}

static int pxa_camera_probe(struct platform_device *pdev)
{
        struct pxa_camera_dev *pcdev;
        struct resource *res;
        void __iomem *base;
        struct dma_slave_config config = {
                .src_addr_width = 0,
                .src_maxburst = 8,
                .direction = DMA_DEV_TO_MEM,
        };
        dma_cap_mask_t mask;
        struct pxad_param params;
        int irq;
        int err = 0, i;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        irq = platform_get_irq(pdev, 0);
        if (!res || irq < 0)
                return -ENODEV;

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

        pcdev->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(pcdev->clk))
                return PTR_ERR(pcdev->clk);

        pcdev->res = res;

        pcdev->pdata = pdev->dev.platform_data;
        if (&pdev->dev.of_node && !pcdev->pdata) {
                err = pxa_camera_pdata_from_dt(&pdev->dev, pcdev);
        } else {
                pcdev->platform_flags = pcdev->pdata->flags;
                pcdev->mclk = pcdev->pdata->mclk_10khz * 10000;
        }
        if (err < 0)
                return err;

        if (!(pcdev->platform_flags & (PXA_CAMERA_DATAWIDTH_8 |
                        PXA_CAMERA_DATAWIDTH_9 | PXA_CAMERA_DATAWIDTH_10))) {
                /*
                 * 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 10 bit\n");
                pcdev->platform_flags |= PXA_CAMERA_DATAWIDTH_10;
        }
        if (pcdev->platform_flags & PXA_CAMERA_DATAWIDTH_8)
                pcdev->width_flags = 1 << 7;
        if (pcdev->platform_flags & PXA_CAMERA_DATAWIDTH_9)
                pcdev->width_flags |= 1 << 8;
        if (pcdev->platform_flags & PXA_CAMERA_DATAWIDTH_10)
                pcdev->width_flags |= 1 << 9;
        if (!pcdev->mclk) {
                dev_warn(&pdev->dev,
                         "mclk == 0! Please, fix your platform data. "
                         "Using default 20MHz\n");
                pcdev->mclk = 20000000;
        }

        pcdev->mclk_divisor = mclk_get_divisor(pdev, pcdev);

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

        /*
         * Request the regions.
         */
        base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(base))
                return PTR_ERR(base);

        pcdev->irq = irq;
        pcdev->base = base;

        /* request dma */
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
        dma_cap_set(DMA_PRIVATE, mask);

        params.prio = 0;
        params.drcmr = 68;
        pcdev->dma_chans[0] =
                dma_request_slave_channel_compat(mask, pxad_filter_fn,
                                                 &params, &pdev->dev, "CI_Y");
        if (!pcdev->dma_chans[0]) {
                dev_err(&pdev->dev, "Can't request DMA for Y\n");
                return -ENODEV;
        }

        params.drcmr = 69;
        pcdev->dma_chans[1] =
                dma_request_slave_channel_compat(mask, pxad_filter_fn,
                                                 &params, &pdev->dev, "CI_U");
        if (!pcdev->dma_chans[1]) {
                dev_err(&pdev->dev, "Can't request DMA for Y\n");
                goto exit_free_dma_y;
        }

        params.drcmr = 70;
        pcdev->dma_chans[2] =
                dma_request_slave_channel_compat(mask, pxad_filter_fn,
                                                 &params, &pdev->dev, "CI_V");
        if (!pcdev->dma_chans[2]) {
                dev_err(&pdev->dev, "Can't request DMA for V\n");
                goto exit_free_dma_u;
        }

        for (i = 0; i < 3; i++) {
                config.src_addr = pcdev->res->start + CIBR0 + i * 8;
                err = dmaengine_slave_config(pcdev->dma_chans[i], &config);
                if (err < 0) {
                        dev_err(&pdev->dev, "dma slave config failed: %d\n",
                                err);
                        goto exit_free_dma;
                }
        }

        /* request irq */
        err = devm_request_irq(&pdev->dev, pcdev->irq, pxa_camera_irq, 0,
                               PXA_CAM_DRV_NAME, pcdev);
        if (err) {
                dev_err(&pdev->dev, "Camera interrupt register failed\n");
                goto exit_free_dma;
        }

        pcdev->soc_host.drv_name        = PXA_CAM_DRV_NAME;
        pcdev->soc_host.ops             = &pxa_soc_camera_host_ops;
        pcdev->soc_host.priv            = pcdev;
        pcdev->soc_host.v4l2_dev.dev    = &pdev->dev;
        pcdev->soc_host.nr              = pdev->id;
        tasklet_init(&pcdev->task_eof, pxa_camera_eof, (unsigned long)pcdev);

        err = soc_camera_host_register(&pcdev->soc_host);
        if (err)
                goto exit_free_dma;

        return 0;

exit_free_dma:
        dma_release_channel(pcdev->dma_chans[2]);
exit_free_dma_u:
        dma_release_channel(pcdev->dma_chans[1]);
exit_free_dma_y:
        dma_release_channel(pcdev->dma_chans[0]);
        return err;
}

static int pxa_camera_remove(struct platform_device *pdev)
{
        struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
        struct pxa_camera_dev *pcdev = container_of(soc_host,
                                        struct pxa_camera_dev, soc_host);

        dma_release_channel(pcdev->dma_chans[0]);
        dma_release_channel(pcdev->dma_chans[1]);
        dma_release_channel(pcdev->dma_chans[2]);

        soc_camera_host_unregister(soc_host);

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

        return 0;
}

static const struct dev_pm_ops pxa_camera_pm = {
        .suspend        = pxa_camera_suspend,
        .resume         = pxa_camera_resume,
};

static const struct of_device_id pxa_camera_of_match[] = {
        { .compatible = "marvell,pxa270-qci", },
        {},
};
MODULE_DEVICE_TABLE(of, pxa_camera_of_match);

static struct platform_driver pxa_camera_driver = {
        .driver         = {
                .name   = PXA_CAM_DRV_NAME,
                .pm     = &pxa_camera_pm,
                .of_match_table = of_match_ptr(pxa_camera_of_match),
        },
        .probe          = pxa_camera_probe,
        .remove         = pxa_camera_remove,
};

module_platform_driver(pxa_camera_driver);

MODULE_DESCRIPTION("PXA27x SoC Camera Host driver");
MODULE_AUTHOR("Guennadi Liakhovetski <kernel@pengutronix.de>");
MODULE_LICENSE("GPL");
MODULE_VERSION(PXA_CAM_VERSION);
MODULE_ALIAS("platform:" PXA_CAM_DRV_NAME);