[PATCH v3 01/10] media: Add Chameleon v3 video interface driver

[Paweł Anikiel]

Add v4l2 driver for the video interface present on the Google
Chameleon v3. The Chameleon v3 uses the video interface to capture
a single video source from a given HDMI or DP connector and write
the resulting frames to memory.

Signed-off-by: Paweł Anikiel <panikiel@xxxxxxxxxx>
---
 drivers/media/platform/Kconfig             |   1 +
 drivers/media/platform/Makefile            |   1 +
 drivers/media/platform/google/Kconfig      |  13 +
 drivers/media/platform/google/Makefile     |   3 +
 drivers/media/platform/google/chv3-video.c | 891 +++++++++++++++++++++
 5 files changed, 909 insertions(+)
 create mode 100644 drivers/media/platform/google/Kconfig
 create mode 100644 drivers/media/platform/google/Makefile
 create mode 100644 drivers/media/platform/google/chv3-video.c

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index 91e54215de3a..b82f7b142b85 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -69,6 +69,7 @@ source "drivers/media/platform/aspeed/Kconfig"
 source "drivers/media/platform/atmel/Kconfig"
 source "drivers/media/platform/cadence/Kconfig"
 source "drivers/media/platform/chips-media/Kconfig"
+source "drivers/media/platform/google/Kconfig"
 source "drivers/media/platform/intel/Kconfig"
 source "drivers/media/platform/marvell/Kconfig"
 source "drivers/media/platform/mediatek/Kconfig"
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 3296ec1ebe16..f7067eb05f76 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -12,6 +12,7 @@ obj-y += aspeed/
 obj-y += atmel/
 obj-y += cadence/
 obj-y += chips-media/
+obj-y += google/
 obj-y += intel/
 obj-y += marvell/
 obj-y += mediatek/
diff --git a/drivers/media/platform/google/Kconfig b/drivers/media/platform/google/Kconfig
new file mode 100644
index 000000000000..9674a4c12e2d
--- /dev/null
+++ b/drivers/media/platform/google/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config VIDEO_CHAMELEONV3
+	tristate "Google Chameleon v3 video driver"
+	depends on V4L_PLATFORM_DRIVERS
+	depends on VIDEO_DEV
+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_FWNODE
+	help
+	  v4l2 driver for the video interface present on the Google
+	  Chameleon v3. The Chameleon v3 uses the video interface to
+	  capture a single video source from a given HDMI or DP connector
+	  and write the resulting frames to memory.
diff --git a/drivers/media/platform/google/Makefile b/drivers/media/platform/google/Makefile
new file mode 100644
index 000000000000..cff06486244c
--- /dev/null
+++ b/drivers/media/platform/google/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_VIDEO_CHAMELEONV3) += chv3-video.o
diff --git a/drivers/media/platform/google/chv3-video.c b/drivers/media/platform/google/chv3-video.c
new file mode 100644
index 000000000000..6e782484abaf
--- /dev/null
+++ b/drivers/media/platform/google/chv3-video.c
@@ -0,0 +1,891 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2023-2024 Google LLC.
+ * Author: Paweł Anikiel <panikiel@xxxxxxxxxx>
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/v4l2-dv-timings.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-dv-timings.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-dma-contig.h>
+
+#define DEVICE_NAME	"chv3-video"
+
+#define VIDEO_EN			0x00
+#define VIDEO_EN_BIT			BIT(0)
+#define VIDEO_HEIGHT			0x04
+#define VIDEO_WIDTH			0x08
+#define VIDEO_BUFFERA			0x0c
+#define VIDEO_BUFFERB			0x10
+#define VIDEO_BUFFERSIZE		0x14
+#define VIDEO_RESET			0x18
+#define VIDEO_RESET_BIT			BIT(0)
+#define VIDEO_ERRORSTATUS		0x1c
+#define VIDEO_IOCOLOR			0x20
+#define VIDEO_DATARATE			0x24
+#define VIDEO_DATARATE_SINGLE		0x0
+#define VIDEO_DATARATE_DOUBLE		0x1
+#define VIDEO_PIXELMODE			0x28
+#define VIDEO_PIXELMODE_SINGLE		0x0
+#define VIDEO_PIXELMODE_DOUBLE		0x1
+#define VIDEO_SYNCPOLARITY		0x2c
+#define VIDEO_DMAFORMAT			0x30
+#define VIDEO_DMAFORMAT_8BPC		0x0
+#define VIDEO_DMAFORMAT_10BPC_UPPER	0x1
+#define VIDEO_DMAFORMAT_10BPC_LOWER	0x2
+#define VIDEO_DMAFORMAT_12BPC_UPPER	0x3
+#define VIDEO_DMAFORMAT_12BPC_LOWER	0x4
+#define VIDEO_DMAFORMAT_16BPC		0x5
+#define VIDEO_DMAFORMAT_RAW		0x6
+#define VIDEO_DMAFORMAT_8BPC_PAD	0x7
+#define VIDEO_VERSION			0x34
+#define VIDEO_VERSION_CURRENT		0xc0fb0001
+
+#define VIDEO_IRQ_MASK		0x8
+#define VIDEO_IRQ_CLR		0xc
+#define VIDEO_IRQ_ALL		0xf
+#define VIDEO_IRQ_BUFF0		BIT(0)
+#define VIDEO_IRQ_BUFF1		BIT(1)
+#define VIDEO_IRQ_RESOLUTION	BIT(2)
+#define VIDEO_IRQ_ERROR		BIT(3)
+
+struct chv3_video {
+	struct device *dev;
+	void __iomem *iobase;
+	void __iomem *iobase_irq;
+
+	struct v4l2_device v4l2_dev;
+	struct vb2_queue queue;
+	struct video_device vdev;
+	struct v4l2_pix_format pix_fmt;
+	struct v4l2_dv_timings timings;
+	u32 bytes_per_pixel;
+
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct v4l2_async_notifier notifier;
+	struct v4l2_subdev *subdev;
+	int subdev_source_pad;
+
+	u32 sequence;
+	bool writing_to_a;
+
+	struct list_head bufs;
+	spinlock_t bufs_lock;
+
+	struct mutex video_lock;
+};
+
+struct chv3_video_buffer {
+	struct vb2_v4l2_buffer vb;
+	struct list_head link;
+};
+
+struct chv3_video_config {
+	u32 pixelformat;
+	u32 bytes_per_pixel;
+	u32 dmaformat;
+};
+
+static void chv3_video_set_format_resolution(struct chv3_video *video, u32 width, u32 height)
+{
+	video->pix_fmt.width = width;
+	video->pix_fmt.height = height;
+	video->pix_fmt.bytesperline = width * video->bytes_per_pixel;
+	video->pix_fmt.sizeimage = video->pix_fmt.bytesperline * height;
+}
+
+/*
+ * The video interface has hardware counters which expose the width and
+ * height of the current video stream. It can't reliably detect if the stream
+ * is present or not, so this is only used as a fallback in the case where
+ * we don't have access to the receiver hardware.
+ */
+static int chv3_video_query_dv_timings_fallback(struct chv3_video *video,
+						struct v4l2_dv_timings *timings)
+{
+	u32 width, height;
+
+	width  = readl(video->iobase + VIDEO_WIDTH);
+	height = readl(video->iobase + VIDEO_HEIGHT);
+	if (width == 0 || height == 0)
+		return -ENOLINK;
+
+	memset(timings, 0, sizeof(*timings));
+	timings->type = V4L2_DV_BT_656_1120;
+	timings->bt.width  = width;
+	timings->bt.height = height;
+	timings->bt.pixelclock = width * height * 24;
+
+	return 0;
+}
+
+static int chv3_video_query_dv_timings(struct chv3_video *video, struct v4l2_dv_timings *timings)
+{
+	if (video->subdev) {
+		return v4l2_subdev_call(video->subdev, pad, query_dv_timings,
+					video->subdev_source_pad, timings);
+	} else {
+		return chv3_video_query_dv_timings_fallback(video, timings);
+	}
+}
+
+static const struct v4l2_dv_timings_cap chv3_video_fallback_dv_timings_cap = {
+	.type = V4L2_DV_BT_656_1120,
+	.bt = {
+		.min_width = 640,
+		.max_width = 7680,
+		.min_height = 480,
+		.max_height = 4320,
+		.min_pixelclock = 25000000,
+		.max_pixelclock = 1080000000,
+		.standards = V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
+			V4L2_DV_BT_STD_CVT | V4L2_DV_BT_STD_GTF,
+		.capabilities = V4L2_DV_BT_CAP_PROGRESSIVE |
+			V4L2_DV_BT_CAP_REDUCED_BLANKING |
+			V4L2_DV_BT_CAP_CUSTOM,
+	},
+};
+
+static int chv3_video_enum_dv_timings_fallback(struct chv3_video *video,
+					       struct v4l2_enum_dv_timings *timings)
+{
+	return v4l2_enum_dv_timings_cap(timings, &chv3_video_fallback_dv_timings_cap,
+					NULL, NULL);
+}
+
+static int chv3_video_dv_timings_cap_fallback(struct chv3_video *video,
+					      struct v4l2_dv_timings_cap *cap)
+{
+	*cap = chv3_video_fallback_dv_timings_cap;
+
+	return 0;
+}
+
+static void chv3_video_apply_dv_timings(struct chv3_video *video)
+{
+	struct v4l2_dv_timings timings;
+	int res;
+
+	res = chv3_video_query_dv_timings(video, &timings);
+	if (res)
+		return;
+
+	video->timings = timings;
+	chv3_video_set_format_resolution(video, timings.bt.width, timings.bt.height);
+}
+
+static int chv3_video_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
+{
+	strscpy(cap->driver, DEVICE_NAME, sizeof(cap->driver));
+	strscpy(cap->card, "Chameleon v3 video", sizeof(cap->card));
+
+	return 0;
+}
+
+static int chv3_video_g_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *fmt)
+{
+	struct chv3_video *video = video_drvdata(file);
+
+	fmt->fmt.pix = video->pix_fmt;
+
+	return 0;
+}
+
+static int chv3_video_enum_fmt_vid_cap(struct file *file, void *fh, struct v4l2_fmtdesc *fmt)
+{
+	struct chv3_video *video = video_drvdata(file);
+
+	if (fmt->index != 0)
+		return -EINVAL;
+
+	fmt->flags = 0;
+	fmt->pixelformat = video->pix_fmt.pixelformat;
+
+	return 0;
+}
+
+static int chv3_video_g_input(struct file *file, void *fh, unsigned int *index)
+{
+	*index = 0;
+
+	return 0;
+}
+
+static int chv3_video_s_input(struct file *file, void *fh, unsigned int index)
+{
+	if (index != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int chv3_video_enum_input(struct file *file, void *fh, struct v4l2_input *input)
+{
+	if (input->index != 0)
+		return -EINVAL;
+
+	strscpy(input->name, "input0", sizeof(input->name));
+	input->type = V4L2_INPUT_TYPE_CAMERA;
+	input->capabilities = V4L2_IN_CAP_DV_TIMINGS;
+
+	return 0;
+}
+
+static int chv3_video_g_edid(struct file *file, void *fh, struct v4l2_edid *edid)
+{
+	struct chv3_video *video = video_drvdata(file);
+	int res;
+
+	if (!video->subdev)
+		return -ENOTTY;
+
+	if (edid->pad != 0)
+		return -EINVAL;
+
+	edid->pad = video->subdev_source_pad;
+	res = v4l2_subdev_call(video->subdev, pad, get_edid, edid);
+	edid->pad = 0;
+
+	return res;
+}
+
+static int chv3_video_s_edid(struct file *file, void *fh, struct v4l2_edid *edid)
+{
+	struct chv3_video *video = video_drvdata(file);
+	int res;
+
+	if (!video->subdev)
+		return -ENOTTY;
+
+	if (edid->pad != 0)
+		return -EINVAL;
+
+	edid->pad = video->subdev_source_pad;
+	res = v4l2_subdev_call(video->subdev, pad, set_edid, edid);
+	edid->pad = 0;
+
+	return res;
+}
+
+static int chv3_video_s_dv_timings(struct file *file, void *fh, struct v4l2_dv_timings *timings)
+{
+	struct chv3_video *video = video_drvdata(file);
+
+	if (v4l2_match_dv_timings(&video->timings, timings, 0, false))
+		return 0;
+
+	if (vb2_is_busy(&video->queue))
+		return -EBUSY;
+
+	if (!v4l2_valid_dv_timings(timings, &chv3_video_fallback_dv_timings_cap, NULL, NULL))
+		return -ERANGE;
+
+	video->timings = *timings;
+	chv3_video_set_format_resolution(video, timings->bt.width, timings->bt.height);
+
+	return 0;
+}
+
+static int chv3_video_g_dv_timings(struct file *file, void *fh, struct v4l2_dv_timings *timings)
+{
+	struct chv3_video *video = video_drvdata(file);
+
+	*timings = video->timings;
+	return 0;
+}
+
+static int chv3_video_vidioc_query_dv_timings(struct file *file, void *fh,
+					      struct v4l2_dv_timings *timings)
+{
+	struct chv3_video *video = video_drvdata(file);
+
+	return chv3_video_query_dv_timings(video, timings);
+}
+
+static int chv3_video_enum_dv_timings(struct file *file, void *fh,
+				      struct v4l2_enum_dv_timings *timings)
+{
+	struct chv3_video *video = video_drvdata(file);
+	int res;
+
+	if (timings->pad != 0)
+		return -EINVAL;
+
+	if (video->subdev) {
+		timings->pad = video->subdev_source_pad;
+		res = v4l2_subdev_call(video->subdev, pad, enum_dv_timings, timings);
+		timings->pad = 0;
+		return res;
+	} else {
+		return chv3_video_enum_dv_timings_fallback(video, timings);
+	}
+}
+
+static int chv3_video_dv_timings_cap(struct file *file, void *fh, struct v4l2_dv_timings_cap *cap)
+{
+	struct chv3_video *video = video_drvdata(file);
+	int res;
+
+	if (cap->pad != 0)
+		return -EINVAL;
+
+	if (video->subdev) {
+		cap->pad = video->subdev_source_pad;
+		res = v4l2_subdev_call(video->subdev, pad, dv_timings_cap, cap);
+		cap->pad = 0;
+		return res;
+	} else {
+		return chv3_video_dv_timings_cap_fallback(video, cap);
+	}
+}
+
+static int chv3_video_subscribe_event(struct v4l2_fh *fh,
+				      const struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_SOURCE_CHANGE:
+		return v4l2_src_change_event_subscribe(fh, sub);
+	}
+
+	return v4l2_ctrl_subscribe_event(fh, sub);
+}
+
+static const struct v4l2_ioctl_ops chv3_video_v4l2_ioctl_ops = {
+	.vidioc_querycap = chv3_video_querycap,
+
+	.vidioc_enum_fmt_vid_cap = chv3_video_enum_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap = chv3_video_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap = chv3_video_g_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap = chv3_video_g_fmt_vid_cap,
+
+	.vidioc_enum_input = chv3_video_enum_input,
+	.vidioc_g_input = chv3_video_g_input,
+	.vidioc_s_input = chv3_video_s_input,
+	.vidioc_g_edid = chv3_video_g_edid,
+	.vidioc_s_edid = chv3_video_s_edid,
+
+	.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_expbuf = vb2_ioctl_expbuf,
+	.vidioc_qbuf = vb2_ioctl_qbuf,
+	.vidioc_dqbuf = vb2_ioctl_dqbuf,
+	.vidioc_streamon = vb2_ioctl_streamon,
+	.vidioc_streamoff = vb2_ioctl_streamoff,
+
+	.vidioc_s_dv_timings = chv3_video_s_dv_timings,
+	.vidioc_g_dv_timings = chv3_video_g_dv_timings,
+	.vidioc_query_dv_timings = chv3_video_vidioc_query_dv_timings,
+	.vidioc_enum_dv_timings = chv3_video_enum_dv_timings,
+	.vidioc_dv_timings_cap = chv3_video_dv_timings_cap,
+
+	.vidioc_subscribe_event = chv3_video_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+};
+
+static int chv3_video_queue_setup(struct vb2_queue *q,
+				  unsigned int *nbuffers, unsigned int *nplanes,
+				  unsigned int sizes[], struct device *alloc_devs[])
+{
+	struct chv3_video *video = vb2_get_drv_priv(q);
+
+	if (*nplanes) {
+		if (sizes[0] < video->pix_fmt.sizeimage)
+			return -EINVAL;
+		return 0;
+	}
+	*nplanes = 1;
+	sizes[0] = video->pix_fmt.sizeimage;
+
+	return 0;
+}
+
+/*
+ * There are two address registers: BUFFERA and BUFFERB. The device
+ * alternates writing between them (i.e. even frames go to BUFFERA, odd
+ * ones to BUFFERB).
+ *
+ *  (buffer queue) >     QUEUED ---> QUEUED ---> QUEUED ---> ...
+ *                       BUFFERA     BUFFERB
+ *  (hw writing to this) ^
+ *                (and then to this) ^
+ *
+ * The buffer swapping happens at irq time. When an irq comes, the next
+ * frame is already assigned an address in the buffer queue. This gives
+ * the irq handler a whole frame's worth of time to update the buffer
+ * address register.
+ */
+
+static dma_addr_t chv3_video_buffer_dma_addr(struct chv3_video_buffer *buf)
+{
+	return vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
+}
+
+static void chv3_video_start_frame(struct chv3_video *video, struct chv3_video_buffer *buf)
+{
+	video->writing_to_a = 1;
+	writel(chv3_video_buffer_dma_addr(buf), video->iobase + VIDEO_BUFFERA);
+	writel(VIDEO_EN_BIT, video->iobase + VIDEO_EN);
+}
+
+static void chv3_video_next_frame(struct chv3_video *video, struct chv3_video_buffer *buf)
+{
+	u32 reg = video->writing_to_a ? VIDEO_BUFFERB : VIDEO_BUFFERA;
+
+	writel(chv3_video_buffer_dma_addr(buf), video->iobase + reg);
+}
+
+static int chv3_video_start_streaming(struct vb2_queue *q, unsigned int count)
+{
+	struct chv3_video *video = vb2_get_drv_priv(q);
+	struct chv3_video_buffer *buf;
+	unsigned long flags;
+
+	video->sequence = 0;
+	writel(video->pix_fmt.sizeimage, video->iobase + VIDEO_BUFFERSIZE);
+
+	spin_lock_irqsave(&video->bufs_lock, flags);
+	buf = list_first_entry_or_null(&video->bufs, struct chv3_video_buffer, link);
+	if (buf) {
+		chv3_video_start_frame(video, buf);
+		if (!list_is_last(&buf->link, &video->bufs))
+			chv3_video_next_frame(video, list_next_entry(buf, link));
+	}
+	spin_unlock_irqrestore(&video->bufs_lock, flags);
+
+	return 0;
+}
+
+static void chv3_video_stop_streaming(struct vb2_queue *q)
+{
+	struct chv3_video *video = vb2_get_drv_priv(q);
+	struct chv3_video_buffer *buf;
+	unsigned long flags;
+
+	writel(0, video->iobase + VIDEO_EN);
+
+	spin_lock_irqsave(&video->bufs_lock, flags);
+	list_for_each_entry(buf, &video->bufs, link)
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+	INIT_LIST_HEAD(&video->bufs);
+	spin_unlock_irqrestore(&video->bufs_lock, flags);
+}
+
+static void chv3_video_buf_queue(struct vb2_buffer *vb)
+{
+	struct chv3_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	struct vb2_v4l2_buffer *v4l2_buf = to_vb2_v4l2_buffer(vb);
+	struct chv3_video_buffer *buf = container_of(v4l2_buf, struct chv3_video_buffer, vb);
+	bool first, second;
+	unsigned long flags;
+
+	spin_lock_irqsave(&video->bufs_lock, flags);
+	first = list_empty(&video->bufs);
+	second = list_is_singular(&video->bufs);
+	list_add_tail(&buf->link, &video->bufs);
+	if (vb2_is_streaming(vb->vb2_queue)) {
+		if (first)
+			chv3_video_start_frame(video, buf);
+		else if (second)
+			chv3_video_next_frame(video, buf);
+	}
+	spin_unlock_irqrestore(&video->bufs_lock, flags);
+}
+
+static const struct vb2_ops chv3_video_vb2_ops = {
+	.queue_setup = chv3_video_queue_setup,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+	.start_streaming = chv3_video_start_streaming,
+	.stop_streaming = chv3_video_stop_streaming,
+	.buf_queue = chv3_video_buf_queue,
+};
+
+static int chv3_video_open(struct file *file)
+{
+	struct chv3_video *video = video_drvdata(file);
+	int res;
+
+	mutex_lock(&video->video_lock);
+	res = v4l2_fh_open(file);
+	if (!res) {
+		if (v4l2_fh_is_singular_file(file))
+			chv3_video_apply_dv_timings(video);
+	}
+	mutex_unlock(&video->video_lock);
+
+	return res;
+}
+
+static const struct v4l2_file_operations chv3_video_v4l2_fops = {
+	.owner = THIS_MODULE,
+	.open = chv3_video_open,
+	.release = vb2_fop_release,
+	.unlocked_ioctl = video_ioctl2,
+	.mmap = vb2_fop_mmap,
+	.poll = vb2_fop_poll,
+};
+
+static void chv3_video_frame_irq(struct chv3_video *video)
+{
+	struct chv3_video_buffer *buf;
+
+	spin_lock(&video->bufs_lock);
+
+	buf = list_first_entry_or_null(&video->bufs, struct chv3_video_buffer, link);
+	if (!buf)
+		goto empty;
+	list_del(&buf->link);
+
+	vb2_set_plane_payload(&buf->vb.vb2_buf, 0, video->pix_fmt.sizeimage);
+	buf->vb.vb2_buf.timestamp = ktime_get_ns();
+	buf->vb.sequence = video->sequence++;
+	buf->vb.field = V4L2_FIELD_NONE;
+	vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
+
+	buf = list_first_entry_or_null(&video->bufs, struct chv3_video_buffer, link);
+	if (buf) {
+		video->writing_to_a = !video->writing_to_a;
+		if (!list_is_last(&buf->link, &video->bufs))
+			chv3_video_next_frame(video, list_next_entry(buf, link));
+	} else {
+		writel(0, video->iobase + VIDEO_EN);
+	}
+empty:
+	spin_unlock(&video->bufs_lock);
+}
+
+static void chv3_video_error_irq(struct chv3_video *video)
+{
+	if (vb2_is_streaming(&video->queue))
+		vb2_queue_error(&video->queue);
+}
+
+static void chv3_video_resolution_irq(struct chv3_video *video)
+{
+	static const struct v4l2_event event = {
+		.type = V4L2_EVENT_SOURCE_CHANGE,
+		.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
+	};
+
+	v4l2_event_queue(&video->vdev, &event);
+	chv3_video_error_irq(video);
+}
+
+static irqreturn_t chv3_video_isr(int irq, void *data)
+{
+	struct chv3_video *video = data;
+	unsigned int reg;
+
+	reg = readl(video->iobase_irq + VIDEO_IRQ_CLR);
+	if (!reg)
+		return IRQ_NONE;
+
+	if (reg & VIDEO_IRQ_BUFF0)
+		chv3_video_frame_irq(video);
+	if (reg & VIDEO_IRQ_BUFF1)
+		chv3_video_frame_irq(video);
+	if (reg & VIDEO_IRQ_RESOLUTION)
+		chv3_video_resolution_irq(video);
+	if (reg & VIDEO_IRQ_ERROR) {
+		dev_warn(video->dev, "error: 0x%x\n",
+			 readl(video->iobase + VIDEO_ERRORSTATUS));
+		chv3_video_error_irq(video);
+	}
+
+	writel(reg, video->iobase_irq + VIDEO_IRQ_CLR);
+
+	return IRQ_HANDLED;
+}
+
+static int chv3_video_check_version(struct chv3_video *video)
+{
+	u32 version;
+
+	version = readl(video->iobase + VIDEO_VERSION);
+	if (version != VIDEO_VERSION_CURRENT) {
+		dev_err(video->dev,
+			"wrong hw version: expected %x, got %x\n",
+			VIDEO_VERSION_CURRENT, version);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void chv3_video_init_timings_and_format(struct chv3_video *video,
+					       const struct chv3_video_config *config)
+{
+	struct v4l2_pix_format *pix = &video->pix_fmt;
+	struct v4l2_dv_timings timings = V4L2_DV_BT_CEA_1920X1080P60;
+
+	video->timings = timings;
+	video->bytes_per_pixel = config->bytes_per_pixel;
+
+	pix->pixelformat = config->pixelformat;
+	pix->field = V4L2_FIELD_NONE;
+	pix->colorspace = V4L2_COLORSPACE_SRGB;
+	chv3_video_set_format_resolution(video, timings.bt.width, timings.bt.height);
+}
+
+#define notifier_to_video(nf) container_of(nf, struct chv3_video, notifier)
+
+static int chv3_video_async_notify_bound(struct v4l2_async_notifier *notifier,
+					 struct v4l2_subdev *subdev,
+					 struct v4l2_async_connection *asc)
+{
+	struct chv3_video *video = notifier_to_video(notifier);
+	int pad;
+
+	pad = media_entity_get_fwnode_pad(&subdev->entity, asc->match.fwnode,
+					  MEDIA_PAD_FL_SOURCE);
+	if (pad < 0)
+		return pad;
+
+	video->subdev = subdev;
+	video->subdev_source_pad = pad;
+
+	video->v4l2_dev.ctrl_handler = subdev->ctrl_handler;
+
+	return 0;
+}
+
+static void chv3_video_async_notify_unbind(struct v4l2_async_notifier *notifier,
+					   struct v4l2_subdev *subdev,
+					   struct v4l2_async_connection *asc)
+{
+	struct chv3_video *video = notifier_to_video(notifier);
+
+	vb2_video_unregister_device(&video->vdev);
+}
+
+static int chv3_video_async_notify_complete(struct v4l2_async_notifier *notifier)
+{
+	struct chv3_video *video = notifier_to_video(notifier);
+
+	return video_register_device(&video->vdev, VFL_TYPE_VIDEO, -1);
+}
+
+static const struct v4l2_async_notifier_operations chv3_video_async_notify_ops = {
+	.bound = chv3_video_async_notify_bound,
+	.unbind = chv3_video_async_notify_unbind,
+	.complete = chv3_video_async_notify_complete,
+};
+
+static int chv3_video_fallback_init(struct chv3_video *video)
+{
+	int res;
+
+	video->subdev = NULL;
+	video->subdev_source_pad = 0;
+
+	v4l2_ctrl_handler_init(&video->ctrl_handler, 1);
+	v4l2_ctrl_new_std(&video->ctrl_handler, NULL,
+			  V4L2_CID_DV_RX_POWER_PRESENT, 0, 1, 0, 0);
+	res = video->ctrl_handler.error;
+	if (res)
+		goto handler_free;
+
+	video->v4l2_dev.ctrl_handler = &video->ctrl_handler;
+
+	res = video_register_device(&video->vdev, VFL_TYPE_VIDEO, -1);
+	if (res)
+		goto handler_free;
+
+	return 0;
+
+handler_free:
+	v4l2_ctrl_handler_free(&video->ctrl_handler);
+
+	return res;
+}
+
+static int chv3_video_fwnode_init(struct chv3_video *video)
+{
+	struct v4l2_async_connection *asc;
+	struct fwnode_handle *endpoint;
+	int res;
+
+	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(video->dev), NULL);
+	if (!endpoint)
+		return -EINVAL;
+
+	v4l2_async_nf_init(&video->notifier, &video->v4l2_dev);
+
+	asc = v4l2_async_nf_add_fwnode_remote(&video->notifier, endpoint,
+					      struct v4l2_async_connection);
+	fwnode_handle_put(endpoint);
+
+	if (IS_ERR(asc))
+		return PTR_ERR(asc);
+
+	video->notifier.ops = &chv3_video_async_notify_ops;
+	res = v4l2_async_nf_register(&video->notifier);
+	if (res) {
+		v4l2_async_nf_cleanup(&video->notifier);
+		return res;
+	}
+
+	return 0;
+}
+
+static int chv3_video_probe(struct platform_device *pdev)
+{
+	struct chv3_video *video;
+	const struct chv3_video_config *config;
+	int res;
+	int irq;
+
+	video = devm_kzalloc(&pdev->dev, sizeof(*video), GFP_KERNEL);
+	if (!video)
+		return -ENOMEM;
+	video->dev = &pdev->dev;
+	platform_set_drvdata(pdev, video);
+
+	config = device_get_match_data(video->dev);
+
+	/* map register space */
+	video->iobase = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(video->iobase))
+		return PTR_ERR(video->iobase);
+
+	video->iobase_irq = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(video->iobase_irq))
+		return PTR_ERR(video->iobase_irq);
+
+	/* check hw version */
+	res = chv3_video_check_version(video);
+	if (res)
+		return res;
+
+	/* setup interrupts */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENXIO;
+	res = devm_request_irq(&pdev->dev, irq, chv3_video_isr, 0, DEVICE_NAME, video);
+	if (res)
+		return res;
+
+	/* initialize v4l2_device */
+	res = v4l2_device_register(&pdev->dev, &video->v4l2_dev);
+	if (res)
+		return res;
+
+	/* initialize vb2 queue */
+	video->queue.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	video->queue.io_modes = VB2_MMAP | VB2_DMABUF;
+	video->queue.dev = &pdev->dev;
+	video->queue.lock = &video->video_lock;
+	video->queue.ops = &chv3_video_vb2_ops;
+	video->queue.mem_ops = &vb2_dma_contig_memops;
+	video->queue.drv_priv = video;
+	video->queue.buf_struct_size = sizeof(struct chv3_video_buffer);
+	video->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	res = vb2_queue_init(&video->queue);
+	if (res)
+		goto error;
+
+	/* initialize video_device */
+	strscpy(video->vdev.name, DEVICE_NAME, sizeof(video->vdev.name));
+	video->vdev.fops = &chv3_video_v4l2_fops;
+	video->vdev.ioctl_ops = &chv3_video_v4l2_ioctl_ops;
+	video->vdev.lock = &video->video_lock;
+	video->vdev.release = video_device_release_empty;
+	video->vdev.device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+	video->vdev.v4l2_dev = &video->v4l2_dev;
+	video->vdev.queue = &video->queue;
+	video_set_drvdata(&video->vdev, video);
+
+	if (device_get_named_child_node(&pdev->dev, "port"))
+		res = chv3_video_fwnode_init(video);
+	else
+		res = chv3_video_fallback_init(video);
+	if (res)
+		goto error;
+
+	/* initialize rest of driver struct */
+	INIT_LIST_HEAD(&video->bufs);
+	spin_lock_init(&video->bufs_lock);
+	mutex_init(&video->video_lock);
+
+	chv3_video_init_timings_and_format(video, config);
+
+	/* initialize hw */
+	writel(VIDEO_RESET_BIT, video->iobase + VIDEO_RESET);
+	writel(VIDEO_DATARATE_DOUBLE, video->iobase + VIDEO_DATARATE);
+	writel(VIDEO_PIXELMODE_DOUBLE, video->iobase + VIDEO_PIXELMODE);
+	writel(config->dmaformat, video->iobase + VIDEO_DMAFORMAT);
+
+	writel(VIDEO_IRQ_ALL, video->iobase_irq + VIDEO_IRQ_MASK);
+
+	return 0;
+
+error:
+	v4l2_device_unregister(&video->v4l2_dev);
+
+	return res;
+}
+
+static void chv3_video_remove(struct platform_device *pdev)
+{
+	struct chv3_video *video = platform_get_drvdata(pdev);
+
+	/* disable interrupts */
+	writel(0, video->iobase_irq + VIDEO_IRQ_MASK);
+
+	if (video->subdev) {
+		/* notifier is initialized only in non-fallback mode */
+		v4l2_async_nf_unregister(&video->notifier);
+		v4l2_async_nf_cleanup(&video->notifier);
+	} else {
+		/* ctrl handler is initialized only in fallback mode */
+		v4l2_ctrl_handler_free(&video->ctrl_handler);
+	}
+
+	v4l2_device_unregister(&video->v4l2_dev);
+}
+
+static const struct chv3_video_config chv3_video_it = {
+	.pixelformat = V4L2_PIX_FMT_BGRX32,
+	.bytes_per_pixel = 4,
+	.dmaformat = VIDEO_DMAFORMAT_8BPC_PAD,
+};
+
+static const struct chv3_video_config chv3_video_dp = {
+	.pixelformat = V4L2_PIX_FMT_RGB24,
+	.bytes_per_pixel = 3,
+	.dmaformat = VIDEO_DMAFORMAT_8BPC,
+};
+
+static const struct of_device_id chv3_video_match_table[] = {
+	{ .compatible = "google,chv3-video-it-1.0", .data = &chv3_video_it },
+	{ .compatible = "google,chv3-video-dp-1.0", .data = &chv3_video_dp },
+	{ },
+};
+
+static struct platform_driver chv3_video_platform_driver = {
+	.probe = chv3_video_probe,
+	.remove_new = chv3_video_remove,
+	.driver = {
+		.name = DEVICE_NAME,
+		.of_match_table = chv3_video_match_table,
+	},
+};
+
+module_platform_driver(chv3_video_platform_driver);
+
+MODULE_AUTHOR("Paweł Anikiel <panikiel@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Google Chameleon v3 video interface driver");
+MODULE_LICENSE("GPL");
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog