[media] marvell-cam: Separate out the Marvell camera core

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / media / video / marvell-ccic / mcam-core.c

/*
 * The Marvell camera core.  This device appears in a number of settings,
 * so it needs platform-specific support outside of the core.
 *
 * Copyright 2011 Jonathan Corbet corbet@lwn.net
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/dmi.h>
#include <linux/mm.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/videodev2.h>
#include <linux/slab.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-chip-ident.h>
#include <media/ov7670.h>
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#include "mcam-core.h"


/*
 * Internal DMA buffer management.  Since the controller cannot do S/G I/O,
 * we must have physically contiguous buffers to bring frames into.
 * These parameters control how many buffers we use, whether we
 * allocate them at load time (better chance of success, but nails down
 * memory) or when somebody tries to use the camera (riskier), and,
 * for load-time allocation, how big they should be.
 *
 * The controller can cycle through three buffers.  We could use
 * more by flipping pointers around, but it probably makes little
 * sense.
 */

static int alloc_bufs_at_read;
module_param(alloc_bufs_at_read, bool, 0444);
MODULE_PARM_DESC(alloc_bufs_at_read,
                "Non-zero value causes DMA buffers to be allocated when the "
                "video capture device is read, rather than at module load "
                "time.  This saves memory, but decreases the chances of "
                "successfully getting those buffers.");

static int n_dma_bufs = 3;
module_param(n_dma_bufs, uint, 0644);
MODULE_PARM_DESC(n_dma_bufs,
                "The number of DMA buffers to allocate.  Can be either two "
                "(saves memory, makes timing tighter) or three.");

static int dma_buf_size = VGA_WIDTH * VGA_HEIGHT * 2;  /* Worst case */
module_param(dma_buf_size, uint, 0444);
MODULE_PARM_DESC(dma_buf_size,
                "The size of the allocated DMA buffers.  If actual operating "
                "parameters require larger buffers, an attempt to reallocate "
                "will be made.");

static int min_buffers = 1;
module_param(min_buffers, uint, 0644);
MODULE_PARM_DESC(min_buffers,
                "The minimum number of streaming I/O buffers we are willing "
                "to work with.");

static int max_buffers = 10;
module_param(max_buffers, uint, 0644);
MODULE_PARM_DESC(max_buffers,
                "The maximum number of streaming I/O buffers an application "
                "will be allowed to allocate.  These buffers are big and live "
                "in vmalloc space.");

static int flip;
module_param(flip, bool, 0444);
MODULE_PARM_DESC(flip,
                "If set, the sensor will be instructed to flip the image "
                "vertically.");

/*
 * Status flags.  Always manipulated with bit operations.
 */
#define CF_BUF0_VALID    0      /* Buffers valid - first three */
#define CF_BUF1_VALID    1
#define CF_BUF2_VALID    2
#define CF_DMA_ACTIVE    3      /* A frame is incoming */
#define CF_CONFIG_NEEDED 4      /* Must configure hardware */

#define sensor_call(cam, o, f, args...) \
        v4l2_subdev_call(cam->sensor, o, f, ##args)

static struct mcam_format_struct {
        __u8 *desc;
        __u32 pixelformat;
        int bpp;   /* Bytes per pixel */
        enum v4l2_mbus_pixelcode mbus_code;
} mcam_formats[] = {
        {
                .desc           = "YUYV 4:2:2",
                .pixelformat    = V4L2_PIX_FMT_YUYV,
                .mbus_code      = V4L2_MBUS_FMT_YUYV8_2X8,
                .bpp            = 2,
        },
        {
                .desc           = "RGB 444",
                .pixelformat    = V4L2_PIX_FMT_RGB444,
                .mbus_code      = V4L2_MBUS_FMT_RGB444_2X8_PADHI_LE,
                .bpp            = 2,
        },
        {
                .desc           = "RGB 565",
                .pixelformat    = V4L2_PIX_FMT_RGB565,
                .mbus_code      = V4L2_MBUS_FMT_RGB565_2X8_LE,
                .bpp            = 2,
        },
        {
                .desc           = "Raw RGB Bayer",
                .pixelformat    = V4L2_PIX_FMT_SBGGR8,
                .mbus_code      = V4L2_MBUS_FMT_SBGGR8_1X8,
                .bpp            = 1
        },
};
#define N_MCAM_FMTS ARRAY_SIZE(mcam_formats)

static struct mcam_format_struct *mcam_find_format(u32 pixelformat)
{
        unsigned i;

        for (i = 0; i < N_MCAM_FMTS; i++)
                if (mcam_formats[i].pixelformat == pixelformat)
                        return mcam_formats + i;
        /* Not found? Then return the first format. */
        return mcam_formats;
}

/*
 * Start over with DMA buffers - dev_lock needed.
 */
static void mcam_reset_buffers(struct mcam_camera *cam)
{
        int i;

        cam->next_buf = -1;
        for (i = 0; i < cam->nbufs; i++)
                clear_bit(i, &cam->flags);
        cam->specframes = 0;
}

static inline int mcam_needs_config(struct mcam_camera *cam)
{
        return test_bit(CF_CONFIG_NEEDED, &cam->flags);
}

static void mcam_set_config_needed(struct mcam_camera *cam, int needed)
{
        if (needed)
                set_bit(CF_CONFIG_NEEDED, &cam->flags);
        else
                clear_bit(CF_CONFIG_NEEDED, &cam->flags);
}


/*
 * Debugging and related.  FIXME these are broken
 */
#define cam_err(cam, fmt, arg...) \
        dev_err((cam)->dev, fmt, ##arg);
#define cam_warn(cam, fmt, arg...) \
        dev_warn((cam)->dev, fmt, ##arg);
#define cam_dbg(cam, fmt, arg...) \
        dev_dbg((cam)->dev, fmt, ##arg);



/* ------------------------------------------------------------------- */
/*
 * Deal with the controller.
 */

/*
 * Do everything we think we need to have the interface operating
 * according to the desired format.
 */
static void mcam_ctlr_dma(struct mcam_camera *cam)
{
        /*
         * Store the first two Y buffers (we aren't supporting
         * planar formats for now, so no UV bufs).  Then either
         * set the third if it exists, or tell the controller
         * to just use two.
         */
        mcam_reg_write(cam, REG_Y0BAR, cam->dma_handles[0]);
        mcam_reg_write(cam, REG_Y1BAR, cam->dma_handles[1]);
        if (cam->nbufs > 2) {
                mcam_reg_write(cam, REG_Y2BAR, cam->dma_handles[2]);
                mcam_reg_clear_bit(cam, REG_CTRL1, C1_TWOBUFS);
        } else
                mcam_reg_set_bit(cam, REG_CTRL1, C1_TWOBUFS);
        mcam_reg_write(cam, REG_UBAR, 0); /* 32 bits only for now */
}

static void mcam_ctlr_image(struct mcam_camera *cam)
{
        int imgsz;
        struct v4l2_pix_format *fmt = &cam->pix_format;

        imgsz = ((fmt->height << IMGSZ_V_SHIFT) & IMGSZ_V_MASK) |
                (fmt->bytesperline & IMGSZ_H_MASK);
        mcam_reg_write(cam, REG_IMGSIZE, imgsz);
        mcam_reg_write(cam, REG_IMGOFFSET, 0);
        /* YPITCH just drops the last two bits */
        mcam_reg_write_mask(cam, REG_IMGPITCH, fmt->bytesperline,
                        IMGP_YP_MASK);
        /*
         * Tell the controller about the image format we are using.
         */
        switch (cam->pix_format.pixelformat) {
        case V4L2_PIX_FMT_YUYV:
            mcam_reg_write_mask(cam, REG_CTRL0,
                            C0_DF_YUV|C0_YUV_PACKED|C0_YUVE_YUYV,
                            C0_DF_MASK);
            break;

        case V4L2_PIX_FMT_RGB444:
            mcam_reg_write_mask(cam, REG_CTRL0,
                            C0_DF_RGB|C0_RGBF_444|C0_RGB4_XRGB,
                            C0_DF_MASK);
                /* Alpha value? */
            break;

        case V4L2_PIX_FMT_RGB565:
            mcam_reg_write_mask(cam, REG_CTRL0,
                            C0_DF_RGB|C0_RGBF_565|C0_RGB5_BGGR,
                            C0_DF_MASK);
            break;

        default:
            cam_err(cam, "Unknown format %x\n", cam->pix_format.pixelformat);
            break;
        }
        /*
         * Make sure it knows we want to use hsync/vsync.
         */
        mcam_reg_write_mask(cam, REG_CTRL0, C0_SIF_HVSYNC,
                        C0_SIFM_MASK);
}


/*
 * Configure the controller for operation; caller holds the
 * device mutex.
 */
static int mcam_ctlr_configure(struct mcam_camera *cam)
{
        unsigned long flags;

        spin_lock_irqsave(&cam->dev_lock, flags);
        mcam_ctlr_dma(cam);
        mcam_ctlr_image(cam);
        mcam_set_config_needed(cam, 0);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
        return 0;
}

static void mcam_ctlr_irq_enable(struct mcam_camera *cam)
{
        /*
         * Clear any pending interrupts, since we do not
         * expect to have I/O active prior to enabling.
         */
        mcam_reg_write(cam, REG_IRQSTAT, FRAMEIRQS);
        mcam_reg_set_bit(cam, REG_IRQMASK, FRAMEIRQS);
}

static void mcam_ctlr_irq_disable(struct mcam_camera *cam)
{
        mcam_reg_clear_bit(cam, REG_IRQMASK, FRAMEIRQS);
}

/*
 * Make the controller start grabbing images.  Everything must
 * be set up before doing this.
 */
static void mcam_ctlr_start(struct mcam_camera *cam)
{
        /* set_bit performs a read, so no other barrier should be
           needed here */
        mcam_reg_set_bit(cam, REG_CTRL0, C0_ENABLE);
}

static void mcam_ctlr_stop(struct mcam_camera *cam)
{
        mcam_reg_clear_bit(cam, REG_CTRL0, C0_ENABLE);
}

static void mcam_ctlr_init(struct mcam_camera *cam)
{
        unsigned long flags;

        spin_lock_irqsave(&cam->dev_lock, flags);
        /*
         * Make sure it's not powered down.
         */
        mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
        /*
         * Turn off the enable bit.  It sure should be off anyway,
         * but it's good to be sure.
         */
        mcam_reg_clear_bit(cam, REG_CTRL0, C0_ENABLE);
        /*
         * Clock the sensor appropriately.  Controller clock should
         * be 48MHz, sensor "typical" value is half that.
         */
        mcam_reg_write_mask(cam, REG_CLKCTRL, 2, CLK_DIV_MASK);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
}


/*
 * Stop the controller, and don't return until we're really sure that no
 * further DMA is going on.
 */
static void mcam_ctlr_stop_dma(struct mcam_camera *cam)
{
        unsigned long flags;

        /*
         * Theory: stop the camera controller (whether it is operating
         * or not).  Delay briefly just in case we race with the SOF
         * interrupt, then wait until no DMA is active.
         */
        spin_lock_irqsave(&cam->dev_lock, flags);
        mcam_ctlr_stop(cam);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
        mdelay(1);
        wait_event_timeout(cam->iowait,
                        !test_bit(CF_DMA_ACTIVE, &cam->flags), HZ);
        if (test_bit(CF_DMA_ACTIVE, &cam->flags))
                cam_err(cam, "Timeout waiting for DMA to end\n");
                /* This would be bad news - what now? */
        spin_lock_irqsave(&cam->dev_lock, flags);
        cam->state = S_IDLE;
        mcam_ctlr_irq_disable(cam);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
}

/*
 * Power up and down.
 */
static void mcam_ctlr_power_up(struct mcam_camera *cam)
{
        unsigned long flags;

        spin_lock_irqsave(&cam->dev_lock, flags);
        mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
        cam->plat_power_up(cam);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
        msleep(5); /* Just to be sure */
}

static void mcam_ctlr_power_down(struct mcam_camera *cam)
{
        unsigned long flags;

        spin_lock_irqsave(&cam->dev_lock, flags);
        cam->plat_power_down(cam);
        mcam_reg_set_bit(cam, REG_CTRL1, C1_PWRDWN);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
}

/* -------------------------------------------------------------------- */
/*
 * Communications with the sensor.
 */

static int __mcam_cam_reset(struct mcam_camera *cam)
{
        return sensor_call(cam, core, reset, 0);
}

/*
 * We have found the sensor on the i2c.  Let's try to have a
 * conversation.
 */
static int mcam_cam_init(struct mcam_camera *cam)
{
        struct v4l2_dbg_chip_ident chip;
        int ret;

        mutex_lock(&cam->s_mutex);
        if (cam->state != S_NOTREADY)
                cam_warn(cam, "Cam init with device in funky state %d",
                                cam->state);
        ret = __mcam_cam_reset(cam);
        if (ret)
                goto out;
        chip.ident = V4L2_IDENT_NONE;
        chip.match.type = V4L2_CHIP_MATCH_I2C_ADDR;
        chip.match.addr = cam->sensor_addr;
        ret = sensor_call(cam, core, g_chip_ident, &chip);
        if (ret)
                goto out;
        cam->sensor_type = chip.ident;
        if (cam->sensor_type != V4L2_IDENT_OV7670) {
                cam_err(cam, "Unsupported sensor type 0x%x", cam->sensor_type);
                ret = -EINVAL;
                goto out;
        }
/* Get/set parameters? */
        ret = 0;
        cam->state = S_IDLE;
out:
        mcam_ctlr_power_down(cam);
        mutex_unlock(&cam->s_mutex);
        return ret;
}

/*
 * Configure the sensor to match the parameters we have.  Caller should
 * hold s_mutex
 */
static int mcam_cam_set_flip(struct mcam_camera *cam)
{
        struct v4l2_control ctrl;

        memset(&ctrl, 0, sizeof(ctrl));
        ctrl.id = V4L2_CID_VFLIP;
        ctrl.value = flip;
        return sensor_call(cam, core, s_ctrl, &ctrl);
}


static int mcam_cam_configure(struct mcam_camera *cam)
{
        struct v4l2_mbus_framefmt mbus_fmt;
        int ret;

        v4l2_fill_mbus_format(&mbus_fmt, &cam->pix_format, cam->mbus_code);
        ret = sensor_call(cam, core, init, 0);
        if (ret == 0)
                ret = sensor_call(cam, video, s_mbus_fmt, &mbus_fmt);
        /*
         * OV7670 does weird things if flip is set *before* format...
         */
        ret += mcam_cam_set_flip(cam);
        return ret;
}

/* -------------------------------------------------------------------- */
/*
 * DMA buffer management.  These functions need s_mutex held.
 */

/* FIXME: this is inefficient as hell, since dma_alloc_coherent just
 * does a get_free_pages() call, and we waste a good chunk of an orderN
 * allocation.  Should try to allocate the whole set in one chunk.
 */
static int mcam_alloc_dma_bufs(struct mcam_camera *cam, int loadtime)
{
        int i;

        mcam_set_config_needed(cam, 1);
        if (loadtime)
                cam->dma_buf_size = dma_buf_size;
        else
                cam->dma_buf_size = cam->pix_format.sizeimage;
        if (n_dma_bufs > 3)
                n_dma_bufs = 3;

        cam->nbufs = 0;
        for (i = 0; i < n_dma_bufs; i++) {
                cam->dma_bufs[i] = dma_alloc_coherent(cam->dev,
                                cam->dma_buf_size, cam->dma_handles + i,
                                GFP_KERNEL);
                if (cam->dma_bufs[i] == NULL) {
                        cam_warn(cam, "Failed to allocate DMA buffer\n");
                        break;
                }
                /* For debug, remove eventually */
                memset(cam->dma_bufs[i], 0xcc, cam->dma_buf_size);
                (cam->nbufs)++;
        }

        switch (cam->nbufs) {
        case 1:
                dma_free_coherent(cam->dev, cam->dma_buf_size,
                                cam->dma_bufs[0], cam->dma_handles[0]);
                cam->nbufs = 0;
        case 0:
                cam_err(cam, "Insufficient DMA buffers, cannot operate\n");
                return -ENOMEM;

        case 2:
                if (n_dma_bufs > 2)
                        cam_warn(cam, "Will limp along with only 2 buffers\n");
                break;
        }
        return 0;
}

static void mcam_free_dma_bufs(struct mcam_camera *cam)
{
        int i;

        for (i = 0; i < cam->nbufs; i++) {
                dma_free_coherent(cam->dev, cam->dma_buf_size,
                                cam->dma_bufs[i], cam->dma_handles[i]);
                cam->dma_bufs[i] = NULL;
        }
        cam->nbufs = 0;
}





/* ----------------------------------------------------------------------- */
/*
 * Here starts the V4L2 interface code.
 */

/*
 * Read an image from the device.
 */
static ssize_t mcam_deliver_buffer(struct mcam_camera *cam,
                char __user *buffer, size_t len, loff_t *pos)
{
        int bufno;
        unsigned long flags;

        spin_lock_irqsave(&cam->dev_lock, flags);
        if (cam->next_buf < 0) {
                cam_err(cam, "deliver_buffer: No next buffer\n");
                spin_unlock_irqrestore(&cam->dev_lock, flags);
                return -EIO;
        }
        bufno = cam->next_buf;
        clear_bit(bufno, &cam->flags);
        if (++(cam->next_buf) >= cam->nbufs)
                cam->next_buf = 0;
        if (!test_bit(cam->next_buf, &cam->flags))
                cam->next_buf = -1;
        cam->specframes = 0;
        spin_unlock_irqrestore(&cam->dev_lock, flags);

        if (len > cam->pix_format.sizeimage)
                len = cam->pix_format.sizeimage;
        if (copy_to_user(buffer, cam->dma_bufs[bufno], len))
                return -EFAULT;
        (*pos) += len;
        return len;
}

/*
 * Get everything ready, and start grabbing frames.
 */
static int mcam_read_setup(struct mcam_camera *cam, enum mcam_state state)
{
        int ret;
        unsigned long flags;

        /*
         * Configuration.  If we still don't have DMA buffers,
         * make one last, desperate attempt.
         */
        if (cam->nbufs == 0)
                if (mcam_alloc_dma_bufs(cam, 0))
                        return -ENOMEM;

        if (mcam_needs_config(cam)) {
                mcam_cam_configure(cam);
                ret = mcam_ctlr_configure(cam);
                if (ret)
                        return ret;
        }

        /*
         * Turn it loose.
         */
        spin_lock_irqsave(&cam->dev_lock, flags);
        mcam_reset_buffers(cam);
        mcam_ctlr_irq_enable(cam);
        cam->state = state;
        mcam_ctlr_start(cam);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
        return 0;
}


static ssize_t mcam_v4l_read(struct file *filp,
                char __user *buffer, size_t len, loff_t *pos)
{
        struct mcam_camera *cam = filp->private_data;
        int ret = 0;

        /*
         * Perhaps we're in speculative read mode and already
         * have data?
         */
        mutex_lock(&cam->s_mutex);
        if (cam->state == S_SPECREAD) {
                if (cam->next_buf >= 0) {
                        ret = mcam_deliver_buffer(cam, buffer, len, pos);
                        if (ret != 0)
                                goto out_unlock;
                }
        } else if (cam->state == S_FLAKED || cam->state == S_NOTREADY) {
                ret = -EIO;
                goto out_unlock;
        } else if (cam->state != S_IDLE) {
                ret = -EBUSY;
                goto out_unlock;
        }

        /*
         * v4l2: multiple processes can open the device, but only
         * one gets to grab data from it.
         */
        if (cam->owner && cam->owner != filp) {
                ret = -EBUSY;
                goto out_unlock;
        }
        cam->owner = filp;

        /*
         * Do setup if need be.
         */
        if (cam->state != S_SPECREAD) {
                ret = mcam_read_setup(cam, S_SINGLEREAD);
                if (ret)
                        goto out_unlock;
        }
        /*
         * Wait for something to happen.  This should probably
         * be interruptible (FIXME).
         */
        wait_event_timeout(cam->iowait, cam->next_buf >= 0, HZ);
        if (cam->next_buf < 0) {
                cam_err(cam, "read() operation timed out\n");
                mcam_ctlr_stop_dma(cam);
                ret = -EIO;
                goto out_unlock;
        }
        /*
         * Give them their data and we should be done.
         */
        ret = mcam_deliver_buffer(cam, buffer, len, pos);

out_unlock:
        mutex_unlock(&cam->s_mutex);
        return ret;
}








/*
 * Streaming I/O support.
 */



static int mcam_vidioc_streamon(struct file *filp, void *priv,
                enum v4l2_buf_type type)
{
        struct mcam_camera *cam = filp->private_data;
        int ret = -EINVAL;

        if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                goto out;
        mutex_lock(&cam->s_mutex);
        if (cam->state != S_IDLE || cam->n_sbufs == 0)
                goto out_unlock;

        cam->sequence = 0;
        ret = mcam_read_setup(cam, S_STREAMING);

out_unlock:
        mutex_unlock(&cam->s_mutex);
out:
        return ret;
}


static int mcam_vidioc_streamoff(struct file *filp, void *priv,
                enum v4l2_buf_type type)
{
        struct mcam_camera *cam = filp->private_data;
        int ret = -EINVAL;

        if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                goto out;
        mutex_lock(&cam->s_mutex);
        if (cam->state != S_STREAMING)
                goto out_unlock;

        mcam_ctlr_stop_dma(cam);
        ret = 0;

out_unlock:
        mutex_unlock(&cam->s_mutex);
out:
        return ret;
}



static int mcam_setup_siobuf(struct mcam_camera *cam, int index)
{
        struct mcam_sio_buffer *buf = cam->sb_bufs + index;

        INIT_LIST_HEAD(&buf->list);
        buf->v4lbuf.length = PAGE_ALIGN(cam->pix_format.sizeimage);
        buf->buffer = vmalloc_user(buf->v4lbuf.length);
        if (buf->buffer == NULL)
                return -ENOMEM;
        buf->mapcount = 0;
        buf->cam = cam;

        buf->v4lbuf.index = index;
        buf->v4lbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        buf->v4lbuf.field = V4L2_FIELD_NONE;
        buf->v4lbuf.memory = V4L2_MEMORY_MMAP;
        /*
         * Offset: must be 32-bit even on a 64-bit system.  videobuf-dma-sg
         * just uses the length times the index, but the spec warns
         * against doing just that - vma merging problems.  So we
         * leave a gap between each pair of buffers.
         */
        buf->v4lbuf.m.offset = 2*index*buf->v4lbuf.length;
        return 0;
}

static int mcam_free_sio_buffers(struct mcam_camera *cam)
{
        int i;

        /*
         * If any buffers are mapped, we cannot free them at all.
         */
        for (i = 0; i < cam->n_sbufs; i++)
                if (cam->sb_bufs[i].mapcount > 0)
                        return -EBUSY;
        /*
         * OK, let's do it.
         */
        for (i = 0; i < cam->n_sbufs; i++)
                vfree(cam->sb_bufs[i].buffer);
        cam->n_sbufs = 0;
        kfree(cam->sb_bufs);
        cam->sb_bufs = NULL;
        INIT_LIST_HEAD(&cam->sb_avail);
        INIT_LIST_HEAD(&cam->sb_full);
        return 0;
}



static int mcam_vidioc_reqbufs(struct file *filp, void *priv,
                struct v4l2_requestbuffers *req)
{
        struct mcam_camera *cam = filp->private_data;
        int ret = 0;  /* Silence warning */

        /*
         * Make sure it's something we can do.  User pointers could be
         * implemented without great pain, but that's not been done yet.
         */
        if (req->memory != V4L2_MEMORY_MMAP)
                return -EINVAL;
        /*
         * If they ask for zero buffers, they really want us to stop streaming
         * (if it's happening) and free everything.  Should we check owner?
         */
        mutex_lock(&cam->s_mutex);
        if (req->count == 0) {
                if (cam->state == S_STREAMING)
                        mcam_ctlr_stop_dma(cam);
                ret = mcam_free_sio_buffers(cam);
                goto out;
        }
        /*
         * Device needs to be idle and working.  We *could* try to do the
         * right thing in S_SPECREAD by shutting things down, but it
         * probably doesn't matter.
         */
        if (cam->state != S_IDLE || (cam->owner && cam->owner != filp)) {
                ret = -EBUSY;
                goto out;
        }
        cam->owner = filp;

        if (req->count < min_buffers)
                req->count = min_buffers;
        else if (req->count > max_buffers)
                req->count = max_buffers;
        if (cam->n_sbufs > 0) {
                ret = mcam_free_sio_buffers(cam);
                if (ret)
                        goto out;
        }

        cam->sb_bufs = kzalloc(req->count*sizeof(struct mcam_sio_buffer),
                        GFP_KERNEL);
        if (cam->sb_bufs == NULL) {
                ret = -ENOMEM;
                goto out;
        }
        for (cam->n_sbufs = 0; cam->n_sbufs < req->count; (cam->n_sbufs++)) {
                ret = mcam_setup_siobuf(cam, cam->n_sbufs);
                if (ret)
                        break;
        }

        if (cam->n_sbufs == 0)  /* no luck at all - ret already set */
                kfree(cam->sb_bufs);
        req->count = cam->n_sbufs;  /* In case of partial success */

out:
        mutex_unlock(&cam->s_mutex);
        return ret;
}


static int mcam_vidioc_querybuf(struct file *filp, void *priv,
                struct v4l2_buffer *buf)
{
        struct mcam_camera *cam = filp->private_data;
        int ret = -EINVAL;

        mutex_lock(&cam->s_mutex);
        if (buf->index >= cam->n_sbufs)
                goto out;
        *buf = cam->sb_bufs[buf->index].v4lbuf;
        ret = 0;
out:
        mutex_unlock(&cam->s_mutex);
        return ret;
}

static int mcam_vidioc_qbuf(struct file *filp, void *priv,
                struct v4l2_buffer *buf)
{
        struct mcam_camera *cam = filp->private_data;
        struct mcam_sio_buffer *sbuf;
        int ret = -EINVAL;
        unsigned long flags;

        mutex_lock(&cam->s_mutex);
        if (buf->index >= cam->n_sbufs)
                goto out;
        sbuf = cam->sb_bufs + buf->index;
        if (sbuf->v4lbuf.flags & V4L2_BUF_FLAG_QUEUED) {
                ret = 0; /* Already queued?? */
                goto out;
        }
        if (sbuf->v4lbuf.flags & V4L2_BUF_FLAG_DONE) {
                /* Spec doesn't say anything, seems appropriate tho */
                ret = -EBUSY;
                goto out;
        }
        sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_QUEUED;
        spin_lock_irqsave(&cam->dev_lock, flags);
        list_add(&sbuf->list, &cam->sb_avail);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
        ret = 0;
out:
        mutex_unlock(&cam->s_mutex);
        return ret;
}

static int mcam_vidioc_dqbuf(struct file *filp, void *priv,
                struct v4l2_buffer *buf)
{
        struct mcam_camera *cam = filp->private_data;
        struct mcam_sio_buffer *sbuf;
        int ret = -EINVAL;
        unsigned long flags;

        mutex_lock(&cam->s_mutex);
        if (cam->state != S_STREAMING)
                goto out_unlock;
        if (list_empty(&cam->sb_full) && filp->f_flags & O_NONBLOCK) {
                ret = -EAGAIN;
                goto out_unlock;
        }

        while (list_empty(&cam->sb_full) && cam->state == S_STREAMING) {
                mutex_unlock(&cam->s_mutex);
                if (wait_event_interruptible(cam->iowait,
                                                !list_empty(&cam->sb_full))) {
                        ret = -ERESTARTSYS;
                        goto out;
                }
                mutex_lock(&cam->s_mutex);
        }

        if (cam->state != S_STREAMING)
                ret = -EINTR;
        else {
                spin_lock_irqsave(&cam->dev_lock, flags);
                /* Should probably recheck !list_empty() here */
                sbuf = list_entry(cam->sb_full.next,
                                struct mcam_sio_buffer, list);
                list_del_init(&sbuf->list);
                spin_unlock_irqrestore(&cam->dev_lock, flags);
                sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_DONE;
                *buf = sbuf->v4lbuf;
                ret = 0;
        }

out_unlock:
        mutex_unlock(&cam->s_mutex);
out:
        return ret;
}



static void mcam_v4l_vm_open(struct vm_area_struct *vma)
{
        struct mcam_sio_buffer *sbuf = vma->vm_private_data;
        /*
         * Locking: done under mmap_sem, so we don't need to
         * go back to the camera lock here.
         */
        sbuf->mapcount++;
}


static void mcam_v4l_vm_close(struct vm_area_struct *vma)
{
        struct mcam_sio_buffer *sbuf = vma->vm_private_data;

        mutex_lock(&sbuf->cam->s_mutex);
        sbuf->mapcount--;
        /* Docs say we should stop I/O too... */
        if (sbuf->mapcount == 0)
                sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_MAPPED;
        mutex_unlock(&sbuf->cam->s_mutex);
}

static const struct vm_operations_struct mcam_v4l_vm_ops = {
        .open = mcam_v4l_vm_open,
        .close = mcam_v4l_vm_close
};


static int mcam_v4l_mmap(struct file *filp, struct vm_area_struct *vma)
{
        struct mcam_camera *cam = filp->private_data;
        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
        int ret = -EINVAL;
        int i;
        struct mcam_sio_buffer *sbuf = NULL;

        if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
                return -EINVAL;
        /*
         * Find the buffer they are looking for.
         */
        mutex_lock(&cam->s_mutex);
        for (i = 0; i < cam->n_sbufs; i++)
                if (cam->sb_bufs[i].v4lbuf.m.offset == offset) {
                        sbuf = cam->sb_bufs + i;
                        break;
                }
        if (sbuf == NULL)
                goto out;

        ret = remap_vmalloc_range(vma, sbuf->buffer, 0);
        if (ret)
                goto out;
        vma->vm_flags |= VM_DONTEXPAND;
        vma->vm_private_data = sbuf;
        vma->vm_ops = &mcam_v4l_vm_ops;
        sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_MAPPED;
        mcam_v4l_vm_open(vma);
        ret = 0;
out:
        mutex_unlock(&cam->s_mutex);
        return ret;
}



static int mcam_v4l_open(struct file *filp)
{
        struct mcam_camera *cam = video_drvdata(filp);

        filp->private_data = cam;

        mutex_lock(&cam->s_mutex);
        if (cam->users == 0) {
                mcam_ctlr_power_up(cam);
                __mcam_cam_reset(cam);
                mcam_set_config_needed(cam, 1);
        /* FIXME make sure this is complete */
        }
        (cam->users)++;
        mutex_unlock(&cam->s_mutex);
        return 0;
}


static int mcam_v4l_release(struct file *filp)
{
        struct mcam_camera *cam = filp->private_data;

        mutex_lock(&cam->s_mutex);
        (cam->users)--;
        if (filp == cam->owner) {
                mcam_ctlr_stop_dma(cam);
                mcam_free_sio_buffers(cam);
                cam->owner = NULL;
        }
        if (cam->users == 0) {
                mcam_ctlr_power_down(cam);
                if (alloc_bufs_at_read)
                        mcam_free_dma_bufs(cam);
        }
        mutex_unlock(&cam->s_mutex);
        return 0;
}



static unsigned int mcam_v4l_poll(struct file *filp,
                struct poll_table_struct *pt)
{
        struct mcam_camera *cam = filp->private_data;

        poll_wait(filp, &cam->iowait, pt);
        if (cam->next_buf >= 0)
                return POLLIN | POLLRDNORM;
        return 0;
}



static int mcam_vidioc_queryctrl(struct file *filp, void *priv,
                struct v4l2_queryctrl *qc)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, core, queryctrl, qc);
        mutex_unlock(&cam->s_mutex);
        return ret;
}


static int mcam_vidioc_g_ctrl(struct file *filp, void *priv,
                struct v4l2_control *ctrl)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, core, g_ctrl, ctrl);
        mutex_unlock(&cam->s_mutex);
        return ret;
}


static int mcam_vidioc_s_ctrl(struct file *filp, void *priv,
                struct v4l2_control *ctrl)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, core, s_ctrl, ctrl);
        mutex_unlock(&cam->s_mutex);
        return ret;
}





static int mcam_vidioc_querycap(struct file *file, void *priv,
                struct v4l2_capability *cap)
{
        strcpy(cap->driver, "marvell_ccic");
        strcpy(cap->card, "marvell_ccic");
        cap->version = 1;
        cap->capabilities = V4L2_CAP_VIDEO_CAPTURE |
                V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
        return 0;
}


/*
 * The default format we use until somebody says otherwise.
 */
static const struct v4l2_pix_format mcam_def_pix_format = {
        .width          = VGA_WIDTH,
        .height         = VGA_HEIGHT,
        .pixelformat    = V4L2_PIX_FMT_YUYV,
        .field          = V4L2_FIELD_NONE,
        .bytesperline   = VGA_WIDTH*2,
        .sizeimage      = VGA_WIDTH*VGA_HEIGHT*2,
};

static const enum v4l2_mbus_pixelcode mcam_def_mbus_code =
                                        V4L2_MBUS_FMT_YUYV8_2X8;

static int mcam_vidioc_enum_fmt_vid_cap(struct file *filp,
                void *priv, struct v4l2_fmtdesc *fmt)
{
        if (fmt->index >= N_MCAM_FMTS)
                return -EINVAL;
        strlcpy(fmt->description, mcam_formats[fmt->index].desc,
                        sizeof(fmt->description));
        fmt->pixelformat = mcam_formats[fmt->index].pixelformat;
        return 0;
}

static int mcam_vidioc_try_fmt_vid_cap(struct file *filp, void *priv,
                struct v4l2_format *fmt)
{
        struct mcam_camera *cam = priv;
        struct mcam_format_struct *f;
        struct v4l2_pix_format *pix = &fmt->fmt.pix;
        struct v4l2_mbus_framefmt mbus_fmt;
        int ret;

        f = mcam_find_format(pix->pixelformat);
        pix->pixelformat = f->pixelformat;
        v4l2_fill_mbus_format(&mbus_fmt, pix, f->mbus_code);
        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, video, try_mbus_fmt, &mbus_fmt);
        mutex_unlock(&cam->s_mutex);
        v4l2_fill_pix_format(pix, &mbus_fmt);
        pix->bytesperline = pix->width * f->bpp;
        pix->sizeimage = pix->height * pix->bytesperline;
        return ret;
}

static int mcam_vidioc_s_fmt_vid_cap(struct file *filp, void *priv,
                struct v4l2_format *fmt)
{
        struct mcam_camera *cam = priv;
        struct mcam_format_struct *f;
        int ret;

        /*
         * Can't do anything if the device is not idle
         * Also can't if there are streaming buffers in place.
         */
        if (cam->state != S_IDLE || cam->n_sbufs > 0)
                return -EBUSY;

        f = mcam_find_format(fmt->fmt.pix.pixelformat);

        /*
         * See if the formatting works in principle.
         */
        ret = mcam_vidioc_try_fmt_vid_cap(filp, priv, fmt);
        if (ret)
                return ret;
        /*
         * Now we start to change things for real, so let's do it
         * under lock.
         */
        mutex_lock(&cam->s_mutex);
        cam->pix_format = fmt->fmt.pix;
        cam->mbus_code = f->mbus_code;

        /*
         * Make sure we have appropriate DMA buffers.
         */
        ret = -ENOMEM;
        if (cam->nbufs > 0 && cam->dma_buf_size < cam->pix_format.sizeimage)
                mcam_free_dma_bufs(cam);
        if (cam->nbufs == 0) {
                if (mcam_alloc_dma_bufs(cam, 0))
                        goto out;
        }
        /*
         * It looks like this might work, so let's program the sensor.
         */
        ret = mcam_cam_configure(cam);
        if (!ret)
                ret = mcam_ctlr_configure(cam);
out:
        mutex_unlock(&cam->s_mutex);
        return ret;
}

/*
 * Return our stored notion of how the camera is/should be configured.
 * The V4l2 spec wants us to be smarter, and actually get this from
 * the camera (and not mess with it at open time).  Someday.
 */
static int mcam_vidioc_g_fmt_vid_cap(struct file *filp, void *priv,
                struct v4l2_format *f)
{
        struct mcam_camera *cam = priv;

        f->fmt.pix = cam->pix_format;
        return 0;
}

/*
 * We only have one input - the sensor - so minimize the nonsense here.
 */
static int mcam_vidioc_enum_input(struct file *filp, void *priv,
                struct v4l2_input *input)
{
        if (input->index != 0)
                return -EINVAL;

        input->type = V4L2_INPUT_TYPE_CAMERA;
        input->std = V4L2_STD_ALL; /* Not sure what should go here */
        strcpy(input->name, "Camera");
        return 0;
}

static int mcam_vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
{
        *i = 0;
        return 0;
}

static int mcam_vidioc_s_input(struct file *filp, void *priv, unsigned int i)
{
        if (i != 0)
                return -EINVAL;
        return 0;
}

/* from vivi.c */
static int mcam_vidioc_s_std(struct file *filp, void *priv, v4l2_std_id *a)
{
        return 0;
}

/*
 * G/S_PARM.  Most of this is done by the sensor, but we are
 * the level which controls the number of read buffers.
 */
static int mcam_vidioc_g_parm(struct file *filp, void *priv,
                struct v4l2_streamparm *parms)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, video, g_parm, parms);
        mutex_unlock(&cam->s_mutex);
        parms->parm.capture.readbuffers = n_dma_bufs;
        return ret;
}

static int mcam_vidioc_s_parm(struct file *filp, void *priv,
                struct v4l2_streamparm *parms)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, video, s_parm, parms);
        mutex_unlock(&cam->s_mutex);
        parms->parm.capture.readbuffers = n_dma_bufs;
        return ret;
}

static int mcam_vidioc_g_chip_ident(struct file *file, void *priv,
                struct v4l2_dbg_chip_ident *chip)
{
        struct mcam_camera *cam = priv;

        chip->ident = V4L2_IDENT_NONE;
        chip->revision = 0;
        if (v4l2_chip_match_host(&chip->match)) {
                chip->ident = cam->chip_id;
                return 0;
        }
        return sensor_call(cam, core, g_chip_ident, chip);
}

static int mcam_vidioc_enum_framesizes(struct file *filp, void *priv,
                struct v4l2_frmsizeenum *sizes)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, video, enum_framesizes, sizes);
        mutex_unlock(&cam->s_mutex);
        return ret;
}

static int mcam_vidioc_enum_frameintervals(struct file *filp, void *priv,
                struct v4l2_frmivalenum *interval)
{
        struct mcam_camera *cam = priv;
        int ret;

        mutex_lock(&cam->s_mutex);
        ret = sensor_call(cam, video, enum_frameintervals, interval);
        mutex_unlock(&cam->s_mutex);
        return ret;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int mcam_vidioc_g_register(struct file *file, void *priv,
                struct v4l2_dbg_register *reg)
{
        struct mcam_camera *cam = priv;

        if (v4l2_chip_match_host(&reg->match)) {
                reg->val = mcam_reg_read(cam, reg->reg);
                reg->size = 4;
                return 0;
        }
        return sensor_call(cam, core, g_register, reg);
}

static int mcam_vidioc_s_register(struct file *file, void *priv,
                struct v4l2_dbg_register *reg)
{
        struct mcam_camera *cam = priv;

        if (v4l2_chip_match_host(&reg->match)) {
                mcam_reg_write(cam, reg->reg, reg->val);
                return 0;
        }
        return sensor_call(cam, core, s_register, reg);
}
#endif

/*
 * This template device holds all of those v4l2 methods; we
 * clone it for specific real devices.
 */

static const struct v4l2_file_operations mcam_v4l_fops = {
        .owner = THIS_MODULE,
        .open = mcam_v4l_open,
        .release = mcam_v4l_release,
        .read = mcam_v4l_read,
        .poll = mcam_v4l_poll,
        .mmap = mcam_v4l_mmap,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops mcam_v4l_ioctl_ops = {
        .vidioc_querycap        = mcam_vidioc_querycap,
        .vidioc_enum_fmt_vid_cap = mcam_vidioc_enum_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap = mcam_vidioc_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap   = mcam_vidioc_s_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap   = mcam_vidioc_g_fmt_vid_cap,
        .vidioc_enum_input      = mcam_vidioc_enum_input,
        .vidioc_g_input         = mcam_vidioc_g_input,
        .vidioc_s_input         = mcam_vidioc_s_input,
        .vidioc_s_std           = mcam_vidioc_s_std,
        .vidioc_reqbufs         = mcam_vidioc_reqbufs,
        .vidioc_querybuf        = mcam_vidioc_querybuf,
        .vidioc_qbuf            = mcam_vidioc_qbuf,
        .vidioc_dqbuf           = mcam_vidioc_dqbuf,
        .vidioc_streamon        = mcam_vidioc_streamon,
        .vidioc_streamoff       = mcam_vidioc_streamoff,
        .vidioc_queryctrl       = mcam_vidioc_queryctrl,
        .vidioc_g_ctrl          = mcam_vidioc_g_ctrl,
        .vidioc_s_ctrl          = mcam_vidioc_s_ctrl,
        .vidioc_g_parm          = mcam_vidioc_g_parm,
        .vidioc_s_parm          = mcam_vidioc_s_parm,
        .vidioc_enum_framesizes = mcam_vidioc_enum_framesizes,
        .vidioc_enum_frameintervals = mcam_vidioc_enum_frameintervals,
        .vidioc_g_chip_ident    = mcam_vidioc_g_chip_ident,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .vidioc_g_register      = mcam_vidioc_g_register,
        .vidioc_s_register      = mcam_vidioc_s_register,
#endif
};

static struct video_device mcam_v4l_template = {
        .name = "mcam",
        .tvnorms = V4L2_STD_NTSC_M,
        .current_norm = V4L2_STD_NTSC_M,  /* make mplayer happy */

        .fops = &mcam_v4l_fops,
        .ioctl_ops = &mcam_v4l_ioctl_ops,
        .release = video_device_release_empty,
};

/* ---------------------------------------------------------------------- */
/*
 * Interrupt handler stuff
 */



static void mcam_frame_tasklet(unsigned long data)
{
        struct mcam_camera *cam = (struct mcam_camera *) data;
        int i;
        unsigned long flags;
        struct mcam_sio_buffer *sbuf;

        spin_lock_irqsave(&cam->dev_lock, flags);
        for (i = 0; i < cam->nbufs; i++) {
                int bufno = cam->next_buf;
                if (bufno < 0) {  /* "will never happen" */
                        cam_err(cam, "No valid bufs in tasklet!\n");
                        break;
                }
                if (++(cam->next_buf) >= cam->nbufs)
                        cam->next_buf = 0;
                if (!test_bit(bufno, &cam->flags))
                        continue;
                if (list_empty(&cam->sb_avail))
                        break;  /* Leave it valid, hope for better later */
                clear_bit(bufno, &cam->flags);
                sbuf = list_entry(cam->sb_avail.next,
                                struct mcam_sio_buffer, list);
                /*
                 * Drop the lock during the big copy.  This *should* be safe...
                 */
                spin_unlock_irqrestore(&cam->dev_lock, flags);
                memcpy(sbuf->buffer, cam->dma_bufs[bufno],
                                cam->pix_format.sizeimage);
                sbuf->v4lbuf.bytesused = cam->pix_format.sizeimage;
                sbuf->v4lbuf.sequence = cam->buf_seq[bufno];
                sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_QUEUED;
                sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_DONE;
                spin_lock_irqsave(&cam->dev_lock, flags);
                list_move_tail(&sbuf->list, &cam->sb_full);
        }
        if (!list_empty(&cam->sb_full))
                wake_up(&cam->iowait);
        spin_unlock_irqrestore(&cam->dev_lock, flags);
}



static void mcam_frame_complete(struct mcam_camera *cam, int frame)
{
        /*
         * Basic frame housekeeping.
         */
        if (test_bit(frame, &cam->flags) && printk_ratelimit())
                cam_err(cam, "Frame overrun on %d, frames lost\n", frame);
        set_bit(frame, &cam->flags);
        clear_bit(CF_DMA_ACTIVE, &cam->flags);
        if (cam->next_buf < 0)
                cam->next_buf = frame;
        cam->buf_seq[frame] = ++(cam->sequence);

        switch (cam->state) {
        /*
         * If in single read mode, try going speculative.
         */
        case S_SINGLEREAD:
                cam->state = S_SPECREAD;
                cam->specframes = 0;
                wake_up(&cam->iowait);
                break;

        /*
         * If we are already doing speculative reads, and nobody is
         * reading them, just stop.
         */
        case S_SPECREAD:
                if (++(cam->specframes) >= cam->nbufs) {
                        mcam_ctlr_stop(cam);
                        mcam_ctlr_irq_disable(cam);
                        cam->state = S_IDLE;
                }
                wake_up(&cam->iowait);
                break;
        /*
         * For the streaming case, we defer the real work to the
         * camera tasklet.
         *
         * FIXME: if the application is not consuming the buffers,
         * we should eventually put things on hold and restart in
         * vidioc_dqbuf().
         */
        case S_STREAMING:
                tasklet_schedule(&cam->s_tasklet);
                break;

        default:
                cam_err(cam, "Frame interrupt in non-operational state\n");
                break;
        }
}




int mccic_irq(struct mcam_camera *cam, unsigned int irqs)
{
        unsigned int frame, handled = 0;

        mcam_reg_write(cam, REG_IRQSTAT, FRAMEIRQS); /* Clear'em all */
        /*
         * Handle any frame completions.  There really should
         * not be more than one of these, or we have fallen
         * far behind.
         */
        for (frame = 0; frame < cam->nbufs; frame++)
                if (irqs & (IRQ_EOF0 << frame)) {
                        mcam_frame_complete(cam, frame);
                        handled = 1;
                }
        /*
         * If a frame starts, note that we have DMA active.  This
         * code assumes that we won't get multiple frame interrupts
         * at once; may want to rethink that.
         */
        if (irqs & (IRQ_SOF0 | IRQ_SOF1 | IRQ_SOF2)) {
                set_bit(CF_DMA_ACTIVE, &cam->flags);
                handled = 1;
        }
        return handled;
}

/*
 * Registration and such.
 */

/* FIXME this is really platform stuff */
static const struct dmi_system_id olpc_xo1_dmi[] = {
        {
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "OLPC"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "XO"),
                        DMI_MATCH(DMI_PRODUCT_VERSION, "1"),
                },
        },
        { }
};

static struct ov7670_config sensor_cfg = {
        /* This controller only does SMBUS */
        .use_smbus = true,

        /*
         * Exclude QCIF mode, because it only captures a tiny portion
         * of the sensor FOV
         */
        .min_width = 320,
        .min_height = 240,
};


int mccic_register(struct mcam_camera *cam)
{
        struct i2c_board_info ov7670_info = {
                .type = "ov7670",
                .addr = 0x42,
                .platform_data = &sensor_cfg,
        };
        int ret;

        /*
         * Register with V4L
         */
        ret = v4l2_device_register(cam->dev, &cam->v4l2_dev);
        if (ret)
                return ret;

        mutex_init(&cam->s_mutex);
        cam->state = S_NOTREADY;
        mcam_set_config_needed(cam, 1);
        init_waitqueue_head(&cam->iowait);
        cam->pix_format = mcam_def_pix_format;
        cam->mbus_code = mcam_def_mbus_code;
        INIT_LIST_HEAD(&cam->dev_list);
        INIT_LIST_HEAD(&cam->sb_avail);
        INIT_LIST_HEAD(&cam->sb_full);
        tasklet_init(&cam->s_tasklet, mcam_frame_tasklet, (unsigned long) cam);

        mcam_ctlr_init(cam);

        /* Apply XO-1 clock speed */
        if (dmi_check_system(olpc_xo1_dmi))
                sensor_cfg.clock_speed = 45;

        /*
         * Try to find the sensor.
         */
        cam->sensor_addr = ov7670_info.addr;
        cam->sensor = v4l2_i2c_new_subdev_board(&cam->v4l2_dev,
                        &cam->i2c_adapter, &ov7670_info, NULL);
        if (cam->sensor == NULL) {
                ret = -ENODEV;
                goto out_unregister;
        }

        ret = mcam_cam_init(cam);
        if (ret)
                goto out_unregister;
        /*
         * Get the v4l2 setup done.
         */
        mutex_lock(&cam->s_mutex);
        cam->vdev = mcam_v4l_template;
        cam->vdev.debug = 0;
        cam->vdev.v4l2_dev = &cam->v4l2_dev;
        ret = video_register_device(&cam->vdev, VFL_TYPE_GRABBER, -1);
        if (ret)
                goto out;
        video_set_drvdata(&cam->vdev, cam);

        /*
         * If so requested, try to get our DMA buffers now.
         */
        if (!alloc_bufs_at_read) {
                if (mcam_alloc_dma_bufs(cam, 1))
                        cam_warn(cam, "Unable to alloc DMA buffers at load"
                                        " will try again later.");
        }

out:
        mutex_unlock(&cam->s_mutex);
        return ret;
out_unregister:
        v4l2_device_unregister(&cam->v4l2_dev);
        return ret;
}


void mccic_shutdown(struct mcam_camera *cam)
{
        if (cam->users > 0)
                cam_warn(cam, "Removing a device with users!\n");
        if (cam->n_sbufs > 0)
                /* What if they are still mapped?  Shouldn't be, but... */
                mcam_free_sio_buffers(cam);
        mcam_ctlr_stop_dma(cam);
        mcam_ctlr_power_down(cam);
        mcam_free_dma_bufs(cam);
        video_unregister_device(&cam->vdev);
        v4l2_device_unregister(&cam->v4l2_dev);
}

/*
 * Power management
 */
#ifdef CONFIG_PM

void mccic_suspend(struct mcam_camera *cam)
{
        enum mcam_state cstate = cam->state;

        mcam_ctlr_stop_dma(cam);
        mcam_ctlr_power_down(cam);
        cam->state = cstate;
}

int mccic_resume(struct mcam_camera *cam)
{
        int ret = 0;

        mutex_lock(&cam->s_mutex);
        if (cam->users > 0) {
                mcam_ctlr_power_up(cam);
                __mcam_cam_reset(cam);
        } else {
                mcam_ctlr_power_down(cam);
        }
        mutex_unlock(&cam->s_mutex);

        set_bit(CF_CONFIG_NEEDED, &cam->flags);
        if (cam->state == S_SPECREAD)
                cam->state = S_IDLE;  /* Don't bother restarting */
        else if (cam->state == S_SINGLEREAD || cam->state == S_STREAMING)
                ret = mcam_read_setup(cam, cam->state);
        return ret;
}
#endif /* CONFIG_PM */