Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1320 insertions, 0 deletions

diff --git a/drivers/media/platform/via-camera.c b/drivers/media/platform/via-camera.c
new file mode 100644
index 000000000..ed0ad68c5
--- /dev/null
+++ b/drivers/media/platform/via-camera.c
@@ -0,0 +1,1320 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the VIA Chrome integrated camera controller.
+ *
+ * Copyright 2009,2010 Jonathan Corbet <corbet@lwn.net>
+ *
+ * This work was supported by the One Laptop Per Child project
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-image-sizes.h>
+#include <media/i2c/ov7670.h>
+#include <media/videobuf2-dma-sg.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/pm_qos.h>
+#include <linux/via-core.h>
+#include <linux/via-gpio.h>
+#include <linux/via_i2c.h>
+
+#ifdef CONFIG_X86
+#include <asm/olpc.h>
+#else
+#define machine_is_olpc(x) 0
+#endif
+
+#include "via-camera.h"
+
+MODULE_ALIAS("platform:viafb-camera");
+MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
+MODULE_DESCRIPTION("VIA framebuffer-based camera controller driver");
+MODULE_LICENSE("GPL");
+
+static bool flip_image;
+module_param(flip_image, bool, 0444);
+MODULE_PARM_DESC(flip_image,
+		"If set, the sensor will be instructed to flip the image vertically.");
+
+static bool override_serial;
+module_param(override_serial, bool, 0444);
+MODULE_PARM_DESC(override_serial,
+		"The camera driver will normally refuse to load if the XO 1.5 serial port is enabled.  Set this option to force-enable the camera.");
+
+/*
+ * The structure describing our camera.
+ */
+enum viacam_opstate { S_IDLE = 0, S_RUNNING = 1 };
+
+struct via_camera {
+	struct v4l2_device v4l2_dev;
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct video_device vdev;
+	struct v4l2_subdev *sensor;
+	struct platform_device *platdev;
+	struct viafb_dev *viadev;
+	struct mutex lock;
+	enum viacam_opstate opstate;
+	unsigned long flags;
+	struct pm_qos_request qos_request;
+	/*
+	 * GPIO info for power/reset management
+	 */
+	int power_gpio;
+	int reset_gpio;
+	/*
+	 * I/O memory stuff.
+	 */
+	void __iomem *mmio;	/* Where the registers live */
+	void __iomem *fbmem;	/* Frame buffer memory */
+	u32 fb_offset;		/* Reserved memory offset (FB) */
+	/*
+	 * Capture buffers and related.	 The controller supports
+	 * up to three, so that's what we have here.  These buffers
+	 * live in frame buffer memory, so we don't call them "DMA".
+	 */
+	unsigned int cb_offsets[3];	/* offsets into fb mem */
+	u8 __iomem *cb_addrs[3];	/* Kernel-space addresses */
+	int n_cap_bufs;			/* How many are we using? */
+	struct vb2_queue vq;
+	struct list_head buffer_queue;
+	u32 sequence;
+	/*
+	 * Video format information.  sensor_format is kept in a form
+	 * that we can use to pass to the sensor.  We always run the
+	 * sensor in VGA resolution, though, and let the controller
+	 * downscale things if need be.	 So we keep the "real*
+	 * dimensions separately.
+	 */
+	struct v4l2_pix_format sensor_format;
+	struct v4l2_pix_format user_format;
+	u32 mbus_code;
+};
+
+/* buffer for one video frame */
+struct via_buffer {
+	/* common v4l buffer stuff -- must be first */
+	struct vb2_v4l2_buffer		vbuf;
+	struct list_head		queue;
+};
+
+/*
+ * Yes, this is a hack, but there's only going to be one of these
+ * on any system we know of.
+ */
+static struct via_camera *via_cam_info;
+
+/*
+ * Flag values, manipulated with bitops
+ */
+#define CF_DMA_ACTIVE	 0	/* A frame is incoming */
+#define CF_CONFIG_NEEDED 1	/* Must configure hardware */
+
+
+/*
+ * Nasty ugly v4l2 boilerplate.
+ */
+#define sensor_call(cam, optype, func, args...) \
+	v4l2_subdev_call(cam->sensor, optype, func, ##args)
+
+/*
+ * Debugging and related.
+ */
+#define cam_err(cam, fmt, arg...) \
+	dev_err(&(cam)->platdev->dev, fmt, ##arg);
+#define cam_warn(cam, fmt, arg...) \
+	dev_warn(&(cam)->platdev->dev, fmt, ##arg);
+#define cam_dbg(cam, fmt, arg...) \
+	dev_dbg(&(cam)->platdev->dev, fmt, ##arg);
+
+/*
+ * Format handling.  This is ripped almost directly from Hans's changes
+ * to cafe_ccic.c.  It's a little unfortunate; until this change, we
+ * didn't need to know anything about the format except its byte depth;
+ * now this information must be managed at this level too.
+ */
+static struct via_format {
+	__u32 pixelformat;
+	int bpp;   /* Bytes per pixel */
+	u32 mbus_code;
+} via_formats[] = {
+	{
+		.pixelformat	= V4L2_PIX_FMT_YUYV,
+		.mbus_code	= MEDIA_BUS_FMT_YUYV8_2X8,
+		.bpp		= 2,
+	},
+	/* RGB444 and Bayer should be doable, but have never been
+	   tested with this driver. RGB565 seems to work at the default
+	   resolution, but results in color corruption when being scaled by
+	   viacam_set_scaled(), and is disabled as a result. */
+};
+#define N_VIA_FMTS ARRAY_SIZE(via_formats)
+
+static struct via_format *via_find_format(u32 pixelformat)
+{
+	unsigned i;
+
+	for (i = 0; i < N_VIA_FMTS; i++)
+		if (via_formats[i].pixelformat == pixelformat)
+			return via_formats + i;
+	/* Not found? Then return the first format. */
+	return via_formats;
+}
+
+
+/*--------------------------------------------------------------------------*/
+/*
+ * Sensor power/reset management.  This piece is OLPC-specific for
+ * sure; other configurations will have things connected differently.
+ */
+static int via_sensor_power_setup(struct via_camera *cam)
+{
+	int ret;
+
+	cam->power_gpio = viafb_gpio_lookup("VGPIO3");
+	cam->reset_gpio = viafb_gpio_lookup("VGPIO2");
+	if (!gpio_is_valid(cam->power_gpio) || !gpio_is_valid(cam->reset_gpio)) {
+		dev_err(&cam->platdev->dev, "Unable to find GPIO lines\n");
+		return -EINVAL;
+	}
+	ret = gpio_request(cam->power_gpio, "viafb-camera");
+	if (ret) {
+		dev_err(&cam->platdev->dev, "Unable to request power GPIO\n");
+		return ret;
+	}
+	ret = gpio_request(cam->reset_gpio, "viafb-camera");
+	if (ret) {
+		dev_err(&cam->platdev->dev, "Unable to request reset GPIO\n");
+		gpio_free(cam->power_gpio);
+		return ret;
+	}
+	gpio_direction_output(cam->power_gpio, 0);
+	gpio_direction_output(cam->reset_gpio, 0);
+	return 0;
+}
+
+/*
+ * Power up the sensor and perform the reset dance.
+ */
+static void via_sensor_power_up(struct via_camera *cam)
+{
+	gpio_set_value(cam->power_gpio, 1);
+	gpio_set_value(cam->reset_gpio, 0);
+	msleep(20);  /* Probably excessive */
+	gpio_set_value(cam->reset_gpio, 1);
+	msleep(20);
+}
+
+static void via_sensor_power_down(struct via_camera *cam)
+{
+	gpio_set_value(cam->power_gpio, 0);
+	gpio_set_value(cam->reset_gpio, 0);
+}
+
+
+static void via_sensor_power_release(struct via_camera *cam)
+{
+	via_sensor_power_down(cam);
+	gpio_free(cam->power_gpio);
+	gpio_free(cam->reset_gpio);
+}
+
+/* --------------------------------------------------------------------------*/
+/* Sensor ops */
+
+/*
+ * Manage the ov7670 "flip" bit, which needs special help.
+ */
+static int viacam_set_flip(struct via_camera *cam)
+{
+	struct v4l2_control ctrl;
+
+	memset(&ctrl, 0, sizeof(ctrl));
+	ctrl.id = V4L2_CID_VFLIP;
+	ctrl.value = flip_image;
+	return v4l2_s_ctrl(NULL, cam->sensor->ctrl_handler, &ctrl);
+}
+
+/*
+ * Configure the sensor.  It's up to the caller to ensure
+ * that the camera is in the correct operating state.
+ */
+static int viacam_configure_sensor(struct via_camera *cam)
+{
+	struct v4l2_subdev_format format = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+	int ret;
+
+	v4l2_fill_mbus_format(&format.format, &cam->sensor_format, cam->mbus_code);
+	ret = sensor_call(cam, core, init, 0);
+	if (ret == 0)
+		ret = sensor_call(cam, pad, set_fmt, NULL, &format);
+	/*
+	 * OV7670 does weird things if flip is set *before* format...
+	 */
+	if (ret == 0)
+		ret = viacam_set_flip(cam);
+	return ret;
+}
+
+
+
+/* --------------------------------------------------------------------------*/
+/*
+ * Some simple register accessors; they assume that the lock is held.
+ *
+ * Should we want to support the second capture engine, we could
+ * hide the register difference by adding 0x1000 to registers in the
+ * 0x300-350 range.
+ */
+static inline void viacam_write_reg(struct via_camera *cam,
+		int reg, int value)
+{
+	iowrite32(value, cam->mmio + reg);
+}
+
+static inline int viacam_read_reg(struct via_camera *cam, int reg)
+{
+	return ioread32(cam->mmio + reg);
+}
+
+static inline void viacam_write_reg_mask(struct via_camera *cam,
+		int reg, int value, int mask)
+{
+	int tmp = viacam_read_reg(cam, reg);
+
+	tmp = (tmp & ~mask) | (value & mask);
+	viacam_write_reg(cam, reg, tmp);
+}
+
+
+/* --------------------------------------------------------------------------*/
+/* Interrupt management and handling */
+
+static irqreturn_t viacam_quick_irq(int irq, void *data)
+{
+	struct via_camera *cam = data;
+	irqreturn_t ret = IRQ_NONE;
+	int icv;
+
+	/*
+	 * All we do here is to clear the interrupts and tell
+	 * the handler thread to wake up.
+	 */
+	spin_lock(&cam->viadev->reg_lock);
+	icv = viacam_read_reg(cam, VCR_INTCTRL);
+	if (icv & VCR_IC_EAV) {
+		icv |= VCR_IC_EAV|VCR_IC_EVBI|VCR_IC_FFULL;
+		viacam_write_reg(cam, VCR_INTCTRL, icv);
+		ret = IRQ_WAKE_THREAD;
+	}
+	spin_unlock(&cam->viadev->reg_lock);
+	return ret;
+}
+
+/*
+ * Find the next buffer which has somebody waiting on it.
+ */
+static struct via_buffer *viacam_next_buffer(struct via_camera *cam)
+{
+	if (cam->opstate != S_RUNNING)
+		return NULL;
+	if (list_empty(&cam->buffer_queue))
+		return NULL;
+	return list_entry(cam->buffer_queue.next, struct via_buffer, queue);
+}
+
+/*
+ * The threaded IRQ handler.
+ */
+static irqreturn_t viacam_irq(int irq, void *data)
+{
+	struct via_camera *cam = data;
+	struct via_buffer *vb;
+	int bufn;
+	struct sg_table *sgt;
+
+	mutex_lock(&cam->lock);
+	/*
+	 * If there is no place to put the data frame, don't bother
+	 * with anything else.
+	 */
+	vb = viacam_next_buffer(cam);
+	if (vb == NULL)
+		goto done;
+	/*
+	 * Figure out which buffer we just completed.
+	 */
+	bufn = (viacam_read_reg(cam, VCR_INTCTRL) & VCR_IC_ACTBUF) >> 3;
+	bufn -= 1;
+	if (bufn < 0)
+		bufn = cam->n_cap_bufs - 1;
+	/*
+	 * Copy over the data and let any waiters know.
+	 */
+	sgt = vb2_dma_sg_plane_desc(&vb->vbuf.vb2_buf, 0);
+	vb->vbuf.vb2_buf.timestamp = ktime_get_ns();
+	viafb_dma_copy_out_sg(cam->cb_offsets[bufn], sgt->sgl, sgt->nents);
+	vb->vbuf.sequence = cam->sequence++;
+	vb->vbuf.field = V4L2_FIELD_NONE;
+	list_del(&vb->queue);
+	vb2_buffer_done(&vb->vbuf.vb2_buf, VB2_BUF_STATE_DONE);
+done:
+	mutex_unlock(&cam->lock);
+	return IRQ_HANDLED;
+}
+
+
+/*
+ * These functions must mess around with the general interrupt
+ * control register, which is relevant to much more than just the
+ * camera.  Nothing else uses interrupts, though, as of this writing.
+ * Should that situation change, we'll have to improve support at
+ * the via-core level.
+ */
+static void viacam_int_enable(struct via_camera *cam)
+{
+	viacam_write_reg(cam, VCR_INTCTRL,
+			VCR_IC_INTEN|VCR_IC_EAV|VCR_IC_EVBI|VCR_IC_FFULL);
+	viafb_irq_enable(VDE_I_C0AVEN);
+}
+
+static void viacam_int_disable(struct via_camera *cam)
+{
+	viafb_irq_disable(VDE_I_C0AVEN);
+	viacam_write_reg(cam, VCR_INTCTRL, 0);
+}
+
+
+
+/* --------------------------------------------------------------------------*/
+/* Controller operations */
+
+/*
+ * Set up our capture buffers in framebuffer memory.
+ */
+static int viacam_ctlr_cbufs(struct via_camera *cam)
+{
+	int nbuf = cam->viadev->camera_fbmem_size/cam->sensor_format.sizeimage;
+	int i;
+	unsigned int offset;
+
+	/*
+	 * See how many buffers we can work with.
+	 */
+	if (nbuf >= 3) {
+		cam->n_cap_bufs = 3;
+		viacam_write_reg_mask(cam, VCR_CAPINTC, VCR_CI_3BUFS,
+				VCR_CI_3BUFS);
+	} else if (nbuf == 2) {
+		cam->n_cap_bufs = 2;
+		viacam_write_reg_mask(cam, VCR_CAPINTC, 0, VCR_CI_3BUFS);
+	} else {
+		cam_warn(cam, "Insufficient frame buffer memory\n");
+		return -ENOMEM;
+	}
+	/*
+	 * Set them up.
+	 */
+	offset = cam->fb_offset;
+	for (i = 0; i < cam->n_cap_bufs; i++) {
+		cam->cb_offsets[i] = offset;
+		cam->cb_addrs[i] = cam->fbmem + offset;
+		viacam_write_reg(cam, VCR_VBUF1 + i*4, offset & VCR_VBUF_MASK);
+		offset += cam->sensor_format.sizeimage;
+	}
+	return 0;
+}
+
+/*
+ * Set the scaling register for downscaling the image.
+ *
+ * This register works like this...  Vertical scaling is enabled
+ * by bit 26; if that bit is set, downscaling is controlled by the
+ * value in bits 16:25.	 Those bits are divided by 1024 to get
+ * the scaling factor; setting just bit 25 thus cuts the height
+ * in half.
+ *
+ * Horizontal scaling works about the same, but it's enabled by
+ * bit 11, with bits 0:10 giving the numerator of a fraction
+ * (over 2048) for the scaling value.
+ *
+ * This function is naive in that, if the user departs from
+ * the 3x4 VGA scaling factor, the image will distort.	We
+ * could work around that if it really seemed important.
+ */
+static void viacam_set_scale(struct via_camera *cam)
+{
+	unsigned int avscale;
+	int sf;
+
+	if (cam->user_format.width == VGA_WIDTH)
+		avscale = 0;
+	else {
+		sf = (cam->user_format.width*2048)/VGA_WIDTH;
+		avscale = VCR_AVS_HEN | sf;
+	}
+	if (cam->user_format.height < VGA_HEIGHT) {
+		sf = (1024*cam->user_format.height)/VGA_HEIGHT;
+		avscale |= VCR_AVS_VEN | (sf << 16);
+	}
+	viacam_write_reg(cam, VCR_AVSCALE, avscale);
+}
+
+
+/*
+ * Configure image-related information into the capture engine.
+ */
+static void viacam_ctlr_image(struct via_camera *cam)
+{
+	int cicreg;
+
+	/*
+	 * Disable clock before messing with stuff - from the via
+	 * sample driver.
+	 */
+	viacam_write_reg(cam, VCR_CAPINTC, ~(VCR_CI_ENABLE|VCR_CI_CLKEN));
+	/*
+	 * Set up the controller for VGA resolution, modulo magic
+	 * offsets from the via sample driver.
+	 */
+	viacam_write_reg(cam, VCR_HORRANGE, 0x06200120);
+	viacam_write_reg(cam, VCR_VERTRANGE, 0x01de0000);
+	viacam_set_scale(cam);
+	/*
+	 * Image size info.
+	 */
+	viacam_write_reg(cam, VCR_MAXDATA,
+			(cam->sensor_format.height << 16) |
+			(cam->sensor_format.bytesperline >> 3));
+	viacam_write_reg(cam, VCR_MAXVBI, 0);
+	viacam_write_reg(cam, VCR_VSTRIDE,
+			cam->user_format.bytesperline & VCR_VS_STRIDE);
+	/*
+	 * Set up the capture interface control register,
+	 * everything but the "go" bit.
+	 *
+	 * The FIFO threshold is a bit of a magic number; 8 is what
+	 * VIA's sample code uses.
+	 */
+	cicreg = VCR_CI_CLKEN |
+		0x08000000 |		/* FIFO threshold */
+		VCR_CI_FLDINV |		/* OLPC-specific? */
+		VCR_CI_VREFINV |	/* OLPC-specific? */
+		VCR_CI_DIBOTH |		/* Capture both fields */
+		VCR_CI_CCIR601_8;
+	if (cam->n_cap_bufs == 3)
+		cicreg |= VCR_CI_3BUFS;
+	/*
+	 * YUV formats need different byte swapping than RGB.
+	 */
+	if (cam->user_format.pixelformat == V4L2_PIX_FMT_YUYV)
+		cicreg |= VCR_CI_YUYV;
+	else
+		cicreg |= VCR_CI_UYVY;
+	viacam_write_reg(cam, VCR_CAPINTC, cicreg);
+}
+
+
+static int viacam_config_controller(struct via_camera *cam)
+{
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cam->viadev->reg_lock, flags);
+	ret = viacam_ctlr_cbufs(cam);
+	if (!ret)
+		viacam_ctlr_image(cam);
+	spin_unlock_irqrestore(&cam->viadev->reg_lock, flags);
+	clear_bit(CF_CONFIG_NEEDED, &cam->flags);
+	return ret;
+}
+
+/*
+ * Make it start grabbing data.
+ */
+static void viacam_start_engine(struct via_camera *cam)
+{
+	spin_lock_irq(&cam->viadev->reg_lock);
+	viacam_write_reg_mask(cam, VCR_CAPINTC, VCR_CI_ENABLE, VCR_CI_ENABLE);
+	viacam_int_enable(cam);
+	(void) viacam_read_reg(cam, VCR_CAPINTC); /* Force post */
+	cam->opstate = S_RUNNING;
+	spin_unlock_irq(&cam->viadev->reg_lock);
+}
+
+
+static void viacam_stop_engine(struct via_camera *cam)
+{
+	spin_lock_irq(&cam->viadev->reg_lock);
+	viacam_int_disable(cam);
+	viacam_write_reg_mask(cam, VCR_CAPINTC, 0, VCR_CI_ENABLE);
+	(void) viacam_read_reg(cam, VCR_CAPINTC); /* Force post */
+	cam->opstate = S_IDLE;
+	spin_unlock_irq(&cam->viadev->reg_lock);
+}
+
+
+/* --------------------------------------------------------------------------*/
+/* vb2 callback ops */
+
+static struct via_buffer *vb2_to_via_buffer(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+
+	return container_of(vbuf, struct via_buffer, vbuf);
+}
+
+static void viacam_vb2_queue(struct vb2_buffer *vb)
+{
+	struct via_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
+	struct via_buffer *via = vb2_to_via_buffer(vb);
+
+	list_add_tail(&via->queue, &cam->buffer_queue);
+}
+
+static int viacam_vb2_prepare(struct vb2_buffer *vb)
+{
+	struct via_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
+
+	if (vb2_plane_size(vb, 0) < cam->user_format.sizeimage) {
+		cam_dbg(cam,
+			"Plane size too small (%lu < %u)\n",
+			vb2_plane_size(vb, 0),
+			cam->user_format.sizeimage);
+		return -EINVAL;
+	}
+
+	vb2_set_plane_payload(vb, 0, cam->user_format.sizeimage);
+
+	return 0;
+}
+
+static int viacam_vb2_queue_setup(struct vb2_queue *vq,
+				  unsigned int *nbufs,
+				  unsigned int *num_planes, unsigned int sizes[],
+				  struct device *alloc_devs[])
+{
+	struct via_camera *cam = vb2_get_drv_priv(vq);
+	int size = cam->user_format.sizeimage;
+
+	if (*num_planes)
+		return sizes[0] < size ? -EINVAL : 0;
+
+	*num_planes = 1;
+	sizes[0] = size;
+	return 0;
+}
+
+static int viacam_vb2_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct via_camera *cam = vb2_get_drv_priv(vq);
+	struct via_buffer *buf, *tmp;
+	int ret = 0;
+
+	if (cam->opstate != S_IDLE) {
+		ret = -EBUSY;
+		goto out;
+	}
+	/*
+	 * Configure things if need be.
+	 */
+	if (test_bit(CF_CONFIG_NEEDED, &cam->flags)) {
+		ret = viacam_configure_sensor(cam);
+		if (ret)
+			goto out;
+		ret = viacam_config_controller(cam);
+		if (ret)
+			goto out;
+	}
+	cam->sequence = 0;
+	/*
+	 * If the CPU goes into C3, the DMA transfer gets corrupted and
+	 * users start filing unsightly bug reports.  Put in a "latency"
+	 * requirement which will keep the CPU out of the deeper sleep
+	 * states.
+	 */
+	cpu_latency_qos_add_request(&cam->qos_request, 50);
+	viacam_start_engine(cam);
+	return 0;
+out:
+	list_for_each_entry_safe(buf, tmp, &cam->buffer_queue, queue) {
+		list_del(&buf->queue);
+		vb2_buffer_done(&buf->vbuf.vb2_buf, VB2_BUF_STATE_QUEUED);
+	}
+	return ret;
+}
+
+static void viacam_vb2_stop_streaming(struct vb2_queue *vq)
+{
+	struct via_camera *cam = vb2_get_drv_priv(vq);
+	struct via_buffer *buf, *tmp;
+
+	cpu_latency_qos_remove_request(&cam->qos_request);
+	viacam_stop_engine(cam);
+
+	list_for_each_entry_safe(buf, tmp, &cam->buffer_queue, queue) {
+		list_del(&buf->queue);
+		vb2_buffer_done(&buf->vbuf.vb2_buf, VB2_BUF_STATE_ERROR);
+	}
+}
+
+static const struct vb2_ops viacam_vb2_ops = {
+	.queue_setup		= viacam_vb2_queue_setup,
+	.buf_queue		= viacam_vb2_queue,
+	.buf_prepare		= viacam_vb2_prepare,
+	.start_streaming	= viacam_vb2_start_streaming,
+	.stop_streaming		= viacam_vb2_stop_streaming,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+};
+
+/* --------------------------------------------------------------------------*/
+/* File operations */
+
+static int viacam_open(struct file *filp)
+{
+	struct via_camera *cam = video_drvdata(filp);
+	int ret;
+
+	/*
+	 * Note the new user.  If this is the first one, we'll also
+	 * need to power up the sensor.
+	 */
+	mutex_lock(&cam->lock);
+	ret = v4l2_fh_open(filp);
+	if (ret)
+		goto out;
+	if (v4l2_fh_is_singular_file(filp)) {
+		ret = viafb_request_dma();
+
+		if (ret) {
+			v4l2_fh_release(filp);
+			goto out;
+		}
+		via_sensor_power_up(cam);
+		set_bit(CF_CONFIG_NEEDED, &cam->flags);
+	}
+out:
+	mutex_unlock(&cam->lock);
+	return ret;
+}
+
+static int viacam_release(struct file *filp)
+{
+	struct via_camera *cam = video_drvdata(filp);
+	bool last_open;
+
+	mutex_lock(&cam->lock);
+	last_open = v4l2_fh_is_singular_file(filp);
+	_vb2_fop_release(filp, NULL);
+	/*
+	 * Last one out needs to turn out the lights.
+	 */
+	if (last_open) {
+		via_sensor_power_down(cam);
+		viafb_release_dma();
+	}
+	mutex_unlock(&cam->lock);
+	return 0;
+}
+
+static const struct v4l2_file_operations viacam_fops = {
+	.owner		= THIS_MODULE,
+	.open		= viacam_open,
+	.release	= viacam_release,
+	.read		= vb2_fop_read,
+	.poll		= vb2_fop_poll,
+	.mmap		= vb2_fop_mmap,
+	.unlocked_ioctl = video_ioctl2,
+};
+
+/*----------------------------------------------------------------------------*/
+/*
+ * The long list of v4l2 ioctl ops
+ */
+
+/*
+ * Only one input.
+ */
+static int viacam_enum_input(struct file *filp, void *priv,
+		struct v4l2_input *input)
+{
+	if (input->index != 0)
+		return -EINVAL;
+
+	input->type = V4L2_INPUT_TYPE_CAMERA;
+	strscpy(input->name, "Camera", sizeof(input->name));
+	return 0;
+}
+
+static int viacam_g_input(struct file *filp, void *priv, unsigned int *i)
+{
+	*i = 0;
+	return 0;
+}
+
+static int viacam_s_input(struct file *filp, void *priv, unsigned int i)
+{
+	if (i != 0)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * Video format stuff.	Here is our default format until
+ * user space messes with things.
+ */
+static const struct v4l2_pix_format viacam_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,
+	.colorspace	= V4L2_COLORSPACE_SRGB,
+};
+
+static const u32 via_def_mbus_code = MEDIA_BUS_FMT_YUYV8_2X8;
+
+static int viacam_enum_fmt_vid_cap(struct file *filp, void *priv,
+		struct v4l2_fmtdesc *fmt)
+{
+	if (fmt->index >= N_VIA_FMTS)
+		return -EINVAL;
+	fmt->pixelformat = via_formats[fmt->index].pixelformat;
+	return 0;
+}
+
+/*
+ * Figure out proper image dimensions, but always force the
+ * sensor to VGA.
+ */
+static void viacam_fmt_pre(struct v4l2_pix_format *userfmt,
+		struct v4l2_pix_format *sensorfmt)
+{
+	*sensorfmt = *userfmt;
+	if (userfmt->width < QCIF_WIDTH || userfmt->height < QCIF_HEIGHT) {
+		userfmt->width = QCIF_WIDTH;
+		userfmt->height = QCIF_HEIGHT;
+	}
+	if (userfmt->width > VGA_WIDTH || userfmt->height > VGA_HEIGHT) {
+		userfmt->width = VGA_WIDTH;
+		userfmt->height = VGA_HEIGHT;
+	}
+	sensorfmt->width = VGA_WIDTH;
+	sensorfmt->height = VGA_HEIGHT;
+}
+
+static void viacam_fmt_post(struct v4l2_pix_format *userfmt,
+		struct v4l2_pix_format *sensorfmt)
+{
+	struct via_format *f = via_find_format(userfmt->pixelformat);
+
+	sensorfmt->bytesperline = sensorfmt->width * f->bpp;
+	sensorfmt->sizeimage = sensorfmt->height * sensorfmt->bytesperline;
+	userfmt->pixelformat = sensorfmt->pixelformat;
+	userfmt->field = sensorfmt->field;
+	userfmt->bytesperline = 2 * userfmt->width;
+	userfmt->sizeimage = userfmt->bytesperline * userfmt->height;
+	userfmt->colorspace = sensorfmt->colorspace;
+	userfmt->ycbcr_enc = sensorfmt->ycbcr_enc;
+	userfmt->quantization = sensorfmt->quantization;
+	userfmt->xfer_func = sensorfmt->xfer_func;
+}
+
+
+/*
+ * The real work of figuring out a workable format.
+ */
+static int viacam_do_try_fmt(struct via_camera *cam,
+		struct v4l2_pix_format *upix, struct v4l2_pix_format *spix)
+{
+	int ret;
+	struct v4l2_subdev_pad_config pad_cfg;
+	struct v4l2_subdev_format format = {
+		.which = V4L2_SUBDEV_FORMAT_TRY,
+	};
+	struct via_format *f = via_find_format(upix->pixelformat);
+
+	upix->pixelformat = f->pixelformat;
+	viacam_fmt_pre(upix, spix);
+	v4l2_fill_mbus_format(&format.format, spix, f->mbus_code);
+	ret = sensor_call(cam, pad, set_fmt, &pad_cfg, &format);
+	v4l2_fill_pix_format(spix, &format.format);
+	viacam_fmt_post(upix, spix);
+	return ret;
+}
+
+
+
+static int viacam_try_fmt_vid_cap(struct file *filp, void *priv,
+		struct v4l2_format *fmt)
+{
+	struct via_camera *cam = video_drvdata(filp);
+	struct v4l2_format sfmt;
+
+	return viacam_do_try_fmt(cam, &fmt->fmt.pix, &sfmt.fmt.pix);
+}
+
+
+static int viacam_g_fmt_vid_cap(struct file *filp, void *priv,
+		struct v4l2_format *fmt)
+{
+	struct via_camera *cam = video_drvdata(filp);
+
+	fmt->fmt.pix = cam->user_format;
+	return 0;
+}
+
+static int viacam_s_fmt_vid_cap(struct file *filp, void *priv,
+		struct v4l2_format *fmt)
+{
+	struct via_camera *cam = video_drvdata(filp);
+	int ret;
+	struct v4l2_format sfmt;
+	struct via_format *f = via_find_format(fmt->fmt.pix.pixelformat);
+
+	/*
+	 * Camera must be idle or we can't mess with the
+	 * video setup.
+	 */
+	if (cam->opstate != S_IDLE)
+		return -EBUSY;
+	/*
+	 * Let the sensor code look over and tweak the
+	 * requested formatting.
+	 */
+	ret = viacam_do_try_fmt(cam, &fmt->fmt.pix, &sfmt.fmt.pix);
+	if (ret)
+		return ret;
+	/*
+	 * OK, let's commit to the new format.
+	 */
+	cam->user_format = fmt->fmt.pix;
+	cam->sensor_format = sfmt.fmt.pix;
+	cam->mbus_code = f->mbus_code;
+	ret = viacam_configure_sensor(cam);
+	if (!ret)
+		ret = viacam_config_controller(cam);
+	return ret;
+}
+
+static int viacam_querycap(struct file *filp, void *priv,
+		struct v4l2_capability *cap)
+{
+	strscpy(cap->driver, "via-camera", sizeof(cap->driver));
+	strscpy(cap->card, "via-camera", sizeof(cap->card));
+	strscpy(cap->bus_info, "platform:via-camera", sizeof(cap->bus_info));
+	return 0;
+}
+
+/* G/S_PARM */
+
+static int viacam_g_parm(struct file *filp, void *priv,
+		struct v4l2_streamparm *parm)
+{
+	struct via_camera *cam = video_drvdata(filp);
+
+	return v4l2_g_parm_cap(video_devdata(filp), cam->sensor, parm);
+}
+
+static int viacam_s_parm(struct file *filp, void *priv,
+		struct v4l2_streamparm *parm)
+{
+	struct via_camera *cam = video_drvdata(filp);
+
+	return v4l2_s_parm_cap(video_devdata(filp), cam->sensor, parm);
+}
+
+static int viacam_enum_framesizes(struct file *filp, void *priv,
+		struct v4l2_frmsizeenum *sizes)
+{
+	unsigned int i;
+
+	if (sizes->index != 0)
+		return -EINVAL;
+	for (i = 0; i < N_VIA_FMTS; i++)
+		if (sizes->pixel_format == via_formats[i].pixelformat)
+			break;
+	if (i >= N_VIA_FMTS)
+		return -EINVAL;
+	sizes->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
+	sizes->stepwise.min_width = QCIF_WIDTH;
+	sizes->stepwise.min_height = QCIF_HEIGHT;
+	sizes->stepwise.max_width = VGA_WIDTH;
+	sizes->stepwise.max_height = VGA_HEIGHT;
+	sizes->stepwise.step_width = sizes->stepwise.step_height = 1;
+	return 0;
+}
+
+static int viacam_enum_frameintervals(struct file *filp, void *priv,
+		struct v4l2_frmivalenum *interval)
+{
+	struct via_camera *cam = video_drvdata(filp);
+	struct v4l2_subdev_frame_interval_enum fie = {
+		.index = interval->index,
+		.code = cam->mbus_code,
+		.width = cam->sensor_format.width,
+		.height = cam->sensor_format.height,
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < N_VIA_FMTS; i++)
+		if (interval->pixel_format == via_formats[i].pixelformat)
+			break;
+	if (i >= N_VIA_FMTS)
+		return -EINVAL;
+	if (interval->width < QCIF_WIDTH || interval->width > VGA_WIDTH ||
+	    interval->height < QCIF_HEIGHT || interval->height > VGA_HEIGHT)
+		return -EINVAL;
+	ret = sensor_call(cam, pad, enum_frame_interval, NULL, &fie);
+	if (ret)
+		return ret;
+	interval->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+	interval->discrete = fie.interval;
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops viacam_ioctl_ops = {
+	.vidioc_enum_input	= viacam_enum_input,
+	.vidioc_g_input		= viacam_g_input,
+	.vidioc_s_input		= viacam_s_input,
+	.vidioc_enum_fmt_vid_cap = viacam_enum_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap = viacam_try_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap	= viacam_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap	= viacam_s_fmt_vid_cap,
+	.vidioc_querycap	= viacam_querycap,
+	.vidioc_reqbufs		= vb2_ioctl_reqbufs,
+	.vidioc_create_bufs	= vb2_ioctl_create_bufs,
+	.vidioc_querybuf	= vb2_ioctl_querybuf,
+	.vidioc_prepare_buf	= vb2_ioctl_prepare_buf,
+	.vidioc_qbuf		= vb2_ioctl_qbuf,
+	.vidioc_dqbuf		= vb2_ioctl_dqbuf,
+	.vidioc_expbuf		= vb2_ioctl_expbuf,
+	.vidioc_streamon	= vb2_ioctl_streamon,
+	.vidioc_streamoff	= vb2_ioctl_streamoff,
+	.vidioc_g_parm		= viacam_g_parm,
+	.vidioc_s_parm		= viacam_s_parm,
+	.vidioc_enum_framesizes = viacam_enum_framesizes,
+	.vidioc_enum_frameintervals = viacam_enum_frameintervals,
+	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
+};
+
+/*----------------------------------------------------------------------------*/
+
+/*
+ * Power management.
+ */
+#ifdef CONFIG_PM
+
+static int viacam_suspend(void *priv)
+{
+	struct via_camera *cam = priv;
+	enum viacam_opstate state = cam->opstate;
+
+	if (cam->opstate != S_IDLE) {
+		viacam_stop_engine(cam);
+		cam->opstate = state; /* So resume restarts */
+	}
+
+	return 0;
+}
+
+static int viacam_resume(void *priv)
+{
+	struct via_camera *cam = priv;
+	int ret = 0;
+
+	/*
+	 * Get back to a reasonable operating state.
+	 */
+	via_write_reg_mask(VIASR, 0x78, 0, 0x80);
+	via_write_reg_mask(VIASR, 0x1e, 0xc0, 0xc0);
+	viacam_int_disable(cam);
+	set_bit(CF_CONFIG_NEEDED, &cam->flags);
+	/*
+	 * Make sure the sensor's power state is correct
+	 */
+	if (!list_empty(&cam->vdev.fh_list))
+		via_sensor_power_up(cam);
+	else
+		via_sensor_power_down(cam);
+	/*
+	 * If it was operating, try to restart it.
+	 */
+	if (cam->opstate != S_IDLE) {
+		mutex_lock(&cam->lock);
+		ret = viacam_configure_sensor(cam);
+		if (!ret)
+			ret = viacam_config_controller(cam);
+		mutex_unlock(&cam->lock);
+		if (!ret)
+			viacam_start_engine(cam);
+	}
+
+	return ret;
+}
+
+static struct viafb_pm_hooks viacam_pm_hooks = {
+	.suspend = viacam_suspend,
+	.resume = viacam_resume
+};
+
+#endif /* CONFIG_PM */
+
+/*
+ * Setup stuff.
+ */
+
+static const struct video_device viacam_v4l_template = {
+	.name		= "via-camera",
+	.minor		= -1,
+	.fops		= &viacam_fops,
+	.ioctl_ops	= &viacam_ioctl_ops,
+	.release	= video_device_release_empty, /* Check this */
+	.device_caps	= V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
+			  V4L2_CAP_STREAMING,
+};
+
+/*
+ * The OLPC folks put the serial port on the same pin as
+ * the camera.	They also get grumpy if we break the
+ * serial port and keep them from using it.  So we have
+ * to check the serial enable bit and not step on it.
+ */
+#define VIACAM_SERIAL_DEVFN 0x88
+#define VIACAM_SERIAL_CREG 0x46
+#define VIACAM_SERIAL_BIT 0x40
+
+static bool viacam_serial_is_enabled(void)
+{
+	struct pci_bus *pbus = pci_find_bus(0, 0);
+	u8 cbyte;
+
+	if (!pbus)
+		return false;
+	pci_bus_read_config_byte(pbus, VIACAM_SERIAL_DEVFN,
+			VIACAM_SERIAL_CREG, &cbyte);
+	if ((cbyte & VIACAM_SERIAL_BIT) == 0)
+		return false; /* Not enabled */
+	if (!override_serial) {
+		printk(KERN_NOTICE "Via camera: serial port is enabled, " \
+				"refusing to load.\n");
+		printk(KERN_NOTICE "Specify override_serial=1 to force " \
+				"module loading.\n");
+		return true;
+	}
+	printk(KERN_NOTICE "Via camera: overriding serial port\n");
+	pci_bus_write_config_byte(pbus, VIACAM_SERIAL_DEVFN,
+			VIACAM_SERIAL_CREG, cbyte & ~VIACAM_SERIAL_BIT);
+	return false;
+}
+
+static struct ov7670_config sensor_cfg = {
+	/* The XO-1.5 (only known user) clocks the camera at 90MHz. */
+	.clock_speed = 90,
+};
+
+static int viacam_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct i2c_adapter *sensor_adapter;
+	struct viafb_dev *viadev = pdev->dev.platform_data;
+	struct vb2_queue *vq;
+	struct i2c_board_info ov7670_info = {
+		.type = "ov7670",
+		.addr = 0x42 >> 1,
+		.platform_data = &sensor_cfg,
+	};
+
+	/*
+	 * Note that there are actually two capture channels on
+	 * the device.	We only deal with one for now.	That
+	 * is encoded here; nothing else assumes it's dealing with
+	 * a unique capture device.
+	 */
+	struct via_camera *cam;
+
+	/*
+	 * Ensure that frame buffer memory has been set aside for
+	 * this purpose.  As an arbitrary limit, refuse to work
+	 * with less than two frames of VGA 16-bit data.
+	 *
+	 * If we ever support the second port, we'll need to set
+	 * aside more memory.
+	 */
+	if (viadev->camera_fbmem_size < (VGA_HEIGHT*VGA_WIDTH*4)) {
+		printk(KERN_ERR "viacam: insufficient FB memory reserved\n");
+		return -ENOMEM;
+	}
+	if (viadev->engine_mmio == NULL) {
+		printk(KERN_ERR "viacam: No I/O memory, so no pictures\n");
+		return -ENOMEM;
+	}
+
+	if (machine_is_olpc() && viacam_serial_is_enabled())
+		return -EBUSY;
+
+	/*
+	 * Basic structure initialization.
+	 */
+	cam = kzalloc (sizeof(struct via_camera), GFP_KERNEL);
+	if (cam == NULL)
+		return -ENOMEM;
+	via_cam_info = cam;
+	cam->platdev = pdev;
+	cam->viadev = viadev;
+	cam->opstate = S_IDLE;
+	cam->user_format = cam->sensor_format = viacam_def_pix_format;
+	mutex_init(&cam->lock);
+	INIT_LIST_HEAD(&cam->buffer_queue);
+	cam->mmio = viadev->engine_mmio;
+	cam->fbmem = viadev->fbmem;
+	cam->fb_offset = viadev->camera_fbmem_offset;
+	cam->flags = 1 << CF_CONFIG_NEEDED;
+	cam->mbus_code = via_def_mbus_code;
+	/*
+	 * Tell V4L that we exist.
+	 */
+	ret = v4l2_device_register(&pdev->dev, &cam->v4l2_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to register v4l2 device\n");
+		goto out_free;
+	}
+	ret = v4l2_ctrl_handler_init(&cam->ctrl_handler, 10);
+	if (ret)
+		goto out_unregister;
+	cam->v4l2_dev.ctrl_handler = &cam->ctrl_handler;
+	/*
+	 * Convince the system that we can do DMA.
+	 */
+	pdev->dev.dma_mask = &viadev->pdev->dma_mask;
+	dma_set_mask(&pdev->dev, 0xffffffff);
+	/*
+	 * Fire up the capture port.  The write to 0x78 looks purely
+	 * OLPCish; any system will need to tweak 0x1e.
+	 */
+	via_write_reg_mask(VIASR, 0x78, 0, 0x80);
+	via_write_reg_mask(VIASR, 0x1e, 0xc0, 0xc0);
+	/*
+	 * Get the sensor powered up.
+	 */
+	ret = via_sensor_power_setup(cam);
+	if (ret)
+		goto out_ctrl_hdl_free;
+	via_sensor_power_up(cam);
+
+	/*
+	 * See if we can't find it on the bus.	The VIA_PORT_31 assumption
+	 * is OLPC-specific.  0x42 assumption is ov7670-specific.
+	 */
+	sensor_adapter = viafb_find_i2c_adapter(VIA_PORT_31);
+	cam->sensor = v4l2_i2c_new_subdev_board(&cam->v4l2_dev, sensor_adapter,
+			&ov7670_info, NULL);
+	if (cam->sensor == NULL) {
+		dev_err(&pdev->dev, "Unable to find the sensor!\n");
+		ret = -ENODEV;
+		goto out_power_down;
+	}
+	/*
+	 * Get the IRQ.
+	 */
+	viacam_int_disable(cam);
+	ret = request_threaded_irq(viadev->pdev->irq, viacam_quick_irq,
+			viacam_irq, IRQF_SHARED, "via-camera", cam);
+	if (ret)
+		goto out_power_down;
+
+	vq = &cam->vq;
+	vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF | VB2_READ;
+	vq->drv_priv = cam;
+	vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	vq->buf_struct_size = sizeof(struct via_buffer);
+	vq->dev = cam->v4l2_dev.dev;
+
+	vq->ops = &viacam_vb2_ops;
+	vq->mem_ops = &vb2_dma_sg_memops;
+	vq->lock = &cam->lock;
+
+	ret = vb2_queue_init(vq);
+	/*
+	 * Tell V4l2 that we exist.
+	 */
+	cam->vdev = viacam_v4l_template;
+	cam->vdev.v4l2_dev = &cam->v4l2_dev;
+	cam->vdev.lock = &cam->lock;
+	cam->vdev.queue = vq;
+	video_set_drvdata(&cam->vdev, cam);
+	ret = video_register_device(&cam->vdev, VFL_TYPE_VIDEO, -1);
+	if (ret)
+		goto out_irq;
+
+#ifdef CONFIG_PM
+	/*
+	 * Hook into PM events
+	 */
+	viacam_pm_hooks.private = cam;
+	viafb_pm_register(&viacam_pm_hooks);
+#endif
+
+	/* Power the sensor down until somebody opens the device */
+	via_sensor_power_down(cam);
+	return 0;
+
+out_irq:
+	free_irq(viadev->pdev->irq, cam);
+out_power_down:
+	via_sensor_power_release(cam);
+out_ctrl_hdl_free:
+	v4l2_ctrl_handler_free(&cam->ctrl_handler);
+out_unregister:
+	v4l2_device_unregister(&cam->v4l2_dev);
+out_free:
+	kfree(cam);
+	return ret;
+}
+
+static int viacam_remove(struct platform_device *pdev)
+{
+	struct via_camera *cam = via_cam_info;
+	struct viafb_dev *viadev = pdev->dev.platform_data;
+
+	video_unregister_device(&cam->vdev);
+	v4l2_device_unregister(&cam->v4l2_dev);
+#ifdef CONFIG_PM
+	viafb_pm_unregister(&viacam_pm_hooks);
+#endif
+	free_irq(viadev->pdev->irq, cam);
+	via_sensor_power_release(cam);
+	v4l2_ctrl_handler_free(&cam->ctrl_handler);
+	kfree(cam);
+	via_cam_info = NULL;
+	return 0;
+}
+
+static struct platform_driver viacam_driver = {
+	.driver = {
+		.name = "viafb-camera",
+	},
+	.probe = viacam_probe,
+	.remove = viacam_remove,
+};
+
+module_platform_driver(viacam_driver);