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/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.
 */
#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);
	if (cam->chip_id == V4L2_IDENT_CAFE)
		mcam_reg_write(cam, REG_UBAR, 0); /* 32 bits only */
}

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);
	cam->plat_power_up(cam);
	mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
	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);
	/*
	 * School of hard knocks department: be sure we do any register
	 * twiddling on the controller *before* calling the platform
	 * power down routine.
	 */
	mcam_reg_set_bit(cam, REG_CTRL1, C1_PWRDWN);
	cam->plat_power_down(cam);
	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.
 */

static struct ov7670_config sensor_cfg = {
	/*
	 * 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 >> 1,
		.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);

	/*
	 * Try to find the sensor.
	 */
	sensor_cfg.clock_speed = cam->clock_speed;
	sensor_cfg.use_smbus = cam->use_smbus;
	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 we have no users (and we really, really should have no
	 * users) the device will already be powered down.  Trying to
	 * take it down again will wedge the machine, which is frowned
	 * upon.
	 */
	if (cam->users > 0) {
		cam_warn(cam, "Removing a device with users!\n");
		mcam_ctlr_power_down(cam);
	}
	mcam_free_dma_bufs(cam);
	if (cam->n_sbufs > 0)
		/* What if they are still mapped?  Shouldn't be, but... */
		mcam_free_sio_buffers(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 */