media: sunxi: Add A10 CSI driver

The older CSI drivers have camera capture interface different from the one
in the newer ones.

This IP is pretty simple. Some variants (one controller out of two
instances on some SoCs) have an ISP embedded, but there's no code that make
use of it, so we ignored that part for now.

[Sakari Ailus: Wrapped a few long lines, set mbus code using a macro.]

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

8 files changed, 1331 insertions, 0 deletions

diff --git a/drivers/media/platform/sunxi/Kconfig b/drivers/media/platform/sunxi/Kconfig
index 1b6e89cb78b2..71808e93ac2e 100644
--- a/drivers/media/platform/sunxi/Kconfig
+++ b/drivers/media/platform/sunxi/Kconfig
@@ -1 +1,2 @@
+source "drivers/media/platform/sunxi/sun4i-csi/Kconfig"
 source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
diff --git a/drivers/media/platform/sunxi/Makefile b/drivers/media/platform/sunxi/Makefile
index 8d06f98500ee..a05127529006 100644
--- a/drivers/media/platform/sunxi/Makefile
+++ b/drivers/media/platform/sunxi/Makefile
@@ -1 +1,2 @@
+obj-y		+= sun4i-csi/
 obj-y		+= sun6i-csi/
diff --git a/drivers/media/platform/sunxi/sun4i-csi/Kconfig b/drivers/media/platform/sunxi/sun4i-csi/Kconfig
new file mode 100644
index 000000000000..e86e29b6a603
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/Kconfig
@@ -0,0 +1,11 @@
+config VIDEO_SUN4I_CSI
+	tristate "Allwinner A10 CMOS Sensor Interface Support"
+	depends on VIDEO_V4L2 && COMMON_CLK && VIDEO_V4L2_SUBDEV_API && HAS_DMA
+	depends on ARCH_SUNXI || COMPILE_TEST
+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_FWNODE
+	help
+	  This is a V4L2 driver for the Allwinner A10 CSI
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called sun4i_csi.
diff --git a/drivers/media/platform/sunxi/sun4i-csi/Makefile b/drivers/media/platform/sunxi/sun4i-csi/Makefile
new file mode 100644
index 000000000000..7c790a57f5ee
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/Makefile
@@ -0,0 +1,5 @@
+sun4i-csi-y += sun4i_csi.o
+sun4i-csi-y += sun4i_dma.o
+sun4i-csi-y += sun4i_v4l2.o
+
+obj-$(CONFIG_VIDEO_SUN4I_CSI)	+= sun4i-csi.o
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
new file mode 100644
index 000000000000..f36dc6258900
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <maxime.ripard@bootlin.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mediabus.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-dma-contig.h>
+
+#include "sun4i_csi.h"
+
+static const struct media_entity_operations sun4i_csi_video_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int sun4i_csi_notify_bound(struct v4l2_async_notifier *notifier,
+				  struct v4l2_subdev *subdev,
+				  struct v4l2_async_subdev *asd)
+{
+	struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi,
+					     notifier);
+
+	csi->src_subdev = subdev;
+	csi->src_pad = media_entity_get_fwnode_pad(&subdev->entity,
+						   subdev->fwnode,
+						   MEDIA_PAD_FL_SOURCE);
+	if (csi->src_pad < 0) {
+		dev_err(csi->dev, "Couldn't find output pad for subdev %s\n",
+			subdev->name);
+		return csi->src_pad;
+	}
+
+	dev_dbg(csi->dev, "Bound %s pad: %d\n", subdev->name, csi->src_pad);
+	return 0;
+}
+
+static int sun4i_csi_notify_complete(struct v4l2_async_notifier *notifier)
+{
+	struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi,
+					     notifier);
+	struct v4l2_subdev *subdev = &csi->subdev;
+	struct video_device *vdev = &csi->vdev;
+	int ret;
+
+	ret = v4l2_device_register_subdev(&csi->v4l, subdev);
+	if (ret < 0)
+		return ret;
+
+	ret = sun4i_csi_v4l2_register(csi);
+	if (ret < 0)
+		return ret;
+
+	ret = media_device_register(&csi->mdev);
+	if (ret)
+		return ret;
+
+	/* Create link from subdev to main device */
+	ret = media_create_pad_link(&subdev->entity, CSI_SUBDEV_SOURCE,
+				    &vdev->entity, 0,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+	if (ret)
+		goto err_clean_media;
+
+	ret = media_create_pad_link(&csi->src_subdev->entity, csi->src_pad,
+				    &subdev->entity, CSI_SUBDEV_SINK,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+	if (ret)
+		goto err_clean_media;
+
+	ret = v4l2_device_register_subdev_nodes(&csi->v4l);
+	if (ret < 0)
+		goto err_clean_media;
+
+	return 0;
+
+err_clean_media:
+	media_device_unregister(&csi->mdev);
+
+	return ret;
+}
+
+static const struct v4l2_async_notifier_operations sun4i_csi_notify_ops = {
+	.bound		= sun4i_csi_notify_bound,
+	.complete	= sun4i_csi_notify_complete,
+};
+
+static int sun4i_csi_notifier_init(struct sun4i_csi *csi)
+{
+	struct v4l2_fwnode_endpoint vep = {
+		.bus_type = V4L2_MBUS_PARALLEL,
+	};
+	struct fwnode_handle *ep;
+	int ret;
+
+	v4l2_async_notifier_init(&csi->notifier);
+
+	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(csi->dev), 0, 0,
+					     FWNODE_GRAPH_ENDPOINT_NEXT);
+	if (!ep)
+		return -EINVAL;
+
+	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
+	if (ret)
+		goto out;
+
+	csi->bus = vep.bus.parallel;
+
+	ret = v4l2_async_notifier_add_fwnode_remote_subdev(&csi->notifier,
+							   ep, &csi->asd);
+	if (ret)
+		goto out;
+
+	csi->notifier.ops = &sun4i_csi_notify_ops;
+
+out:
+	fwnode_handle_put(ep);
+	return ret;
+}
+
+static int sun4i_csi_probe(struct platform_device *pdev)
+{
+	struct v4l2_subdev *subdev;
+	struct video_device *vdev;
+	struct sun4i_csi *csi;
+	struct resource *res;
+	int ret;
+	int irq;
+
+	csi = devm_kzalloc(&pdev->dev, sizeof(*csi), GFP_KERNEL);
+	if (!csi)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, csi);
+	csi->dev = &pdev->dev;
+	subdev = &csi->subdev;
+	vdev = &csi->vdev;
+
+	csi->mdev.dev = csi->dev;
+	strscpy(csi->mdev.model, "Allwinner Video Capture Device",
+		sizeof(csi->mdev.model));
+	csi->mdev.hw_revision = 0;
+	media_device_init(&csi->mdev);
+	csi->v4l.mdev = &csi->mdev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	csi->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(csi->regs))
+		return PTR_ERR(csi->regs);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	csi->bus_clk = devm_clk_get(&pdev->dev, "bus");
+	if (IS_ERR(csi->bus_clk)) {
+		dev_err(&pdev->dev, "Couldn't get our bus clock\n");
+		return PTR_ERR(csi->bus_clk);
+	}
+
+	csi->isp_clk = devm_clk_get(&pdev->dev, "isp");
+	if (IS_ERR(csi->isp_clk)) {
+		dev_err(&pdev->dev, "Couldn't get our ISP clock\n");
+		return PTR_ERR(csi->isp_clk);
+	}
+
+	csi->ram_clk = devm_clk_get(&pdev->dev, "ram");
+	if (IS_ERR(csi->ram_clk)) {
+		dev_err(&pdev->dev, "Couldn't get our ram clock\n");
+		return PTR_ERR(csi->ram_clk);
+	}
+
+	csi->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(csi->rst)) {
+		dev_err(&pdev->dev, "Couldn't get our reset line\n");
+		return PTR_ERR(csi->rst);
+	}
+
+	/* Initialize subdev */
+	v4l2_subdev_init(subdev, &sun4i_csi_subdev_ops);
+	subdev->flags = V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
+	subdev->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	subdev->owner = THIS_MODULE;
+	snprintf(subdev->name, sizeof(subdev->name), "sun4i-csi-0");
+	v4l2_set_subdevdata(subdev, csi);
+
+	csi->subdev_pads[CSI_SUBDEV_SINK].flags =
+		MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
+	csi->subdev_pads[CSI_SUBDEV_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&subdev->entity, CSI_SUBDEV_PADS,
+				     csi->subdev_pads);
+	if (ret < 0)
+		return ret;
+
+	csi->vdev_pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
+	vdev->entity.ops = &sun4i_csi_video_entity_ops;
+	ret = media_entity_pads_init(&vdev->entity, 1, &csi->vdev_pad);
+	if (ret < 0)
+		return ret;
+
+	ret = sun4i_csi_dma_register(csi, irq);
+	if (ret)
+		goto err_clean_pad;
+
+	ret = sun4i_csi_notifier_init(csi);
+	if (ret)
+		goto err_unregister_media;
+
+	ret = v4l2_async_notifier_register(&csi->v4l, &csi->notifier);
+	if (ret) {
+		dev_err(csi->dev, "Couldn't register our notifier.\n");
+		goto err_unregister_media;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+
+	return 0;
+
+err_unregister_media:
+	media_device_unregister(&csi->mdev);
+	sun4i_csi_dma_unregister(csi);
+
+err_clean_pad:
+	media_device_cleanup(&csi->mdev);
+
+	return ret;
+}
+
+static int sun4i_csi_remove(struct platform_device *pdev)
+{
+	struct sun4i_csi *csi = platform_get_drvdata(pdev);
+
+	v4l2_async_notifier_unregister(&csi->notifier);
+	v4l2_async_notifier_cleanup(&csi->notifier);
+	media_device_unregister(&csi->mdev);
+	sun4i_csi_dma_unregister(csi);
+	media_device_cleanup(&csi->mdev);
+
+	return 0;
+}
+
+static const struct of_device_id sun4i_csi_of_match[] = {
+	{ .compatible = "allwinner,sun7i-a20-csi0" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_csi_of_match);
+
+static int __maybe_unused sun4i_csi_runtime_resume(struct device *dev)
+{
+	struct sun4i_csi *csi = dev_get_drvdata(dev);
+
+	reset_control_deassert(csi->rst);
+	clk_prepare_enable(csi->bus_clk);
+	clk_prepare_enable(csi->ram_clk);
+	clk_set_rate(csi->isp_clk, 80000000);
+	clk_prepare_enable(csi->isp_clk);
+
+	writel(1, csi->regs + CSI_EN_REG);
+
+	return 0;
+}
+
+static int __maybe_unused sun4i_csi_runtime_suspend(struct device *dev)
+{
+	struct sun4i_csi *csi = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(csi->isp_clk);
+	clk_disable_unprepare(csi->ram_clk);
+	clk_disable_unprepare(csi->bus_clk);
+
+	reset_control_assert(csi->rst);
+
+	return 0;
+}
+
+static const struct dev_pm_ops sun4i_csi_pm_ops = {
+	SET_RUNTIME_PM_OPS(sun4i_csi_runtime_suspend,
+			   sun4i_csi_runtime_resume,
+			   NULL)
+};
+
+static struct platform_driver sun4i_csi_driver = {
+	.probe	= sun4i_csi_probe,
+	.remove	= sun4i_csi_remove,
+	.driver	= {
+		.name		= "sun4i-csi",
+		.of_match_table	= sun4i_csi_of_match,
+		.pm		= &sun4i_csi_pm_ops,
+	},
+};
+module_platform_driver(sun4i_csi_driver);
+
+MODULE_DESCRIPTION("Allwinner A10 Camera Sensor Interface driver");
+MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h
new file mode 100644
index 000000000000..001c8bde006c
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_csi.h
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <maxime.ripard@bootlin.com>
+ */
+
+#ifndef _SUN4I_CSI_H_
+#define _SUN4I_CSI_H_
+
+#include <media/media-device.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/videobuf2-core.h>
+
+#define CSI_EN_REG			0x00
+
+#define CSI_CFG_REG			0x04
+#define CSI_CFG_INPUT_FMT(fmt)			((fmt) << 20)
+#define CSI_CFG_OUTPUT_FMT(fmt)			((fmt) << 16)
+#define CSI_CFG_YUV_DATA_SEQ(seq)		((seq) << 8)
+#define CSI_CFG_VSYNC_POL(pol)			((pol) << 2)
+#define CSI_CFG_HSYNC_POL(pol)			((pol) << 1)
+#define CSI_CFG_PCLK_POL(pol)			((pol) << 0)
+
+#define CSI_CPT_CTRL_REG		0x08
+#define CSI_CPT_CTRL_VIDEO_START		BIT(1)
+#define CSI_CPT_CTRL_IMAGE_START		BIT(0)
+
+#define CSI_BUF_ADDR_REG(fifo, buf)	(0x10 + (0x8 * (fifo)) + (0x4 * (buf)))
+
+#define CSI_BUF_CTRL_REG		0x28
+#define CSI_BUF_CTRL_DBN			BIT(2)
+#define CSI_BUF_CTRL_DBS			BIT(1)
+#define CSI_BUF_CTRL_DBE			BIT(0)
+
+#define CSI_INT_EN_REG			0x30
+#define CSI_INT_FRM_DONE			BIT(1)
+#define CSI_INT_CPT_DONE			BIT(0)
+
+#define CSI_INT_STA_REG			0x34
+
+#define CSI_WIN_CTRL_W_REG		0x40
+#define CSI_WIN_CTRL_W_ACTIVE(w)		((w) << 16)
+
+#define CSI_WIN_CTRL_H_REG		0x44
+#define CSI_WIN_CTRL_H_ACTIVE(h)		((h) << 16)
+
+#define CSI_BUF_LEN_REG			0x48
+
+#define CSI_MAX_BUFFER		2
+#define CSI_MAX_HEIGHT		8192U
+#define CSI_MAX_WIDTH		8192U
+
+enum csi_input {
+	CSI_INPUT_RAW	= 0,
+	CSI_INPUT_BT656	= 2,
+	CSI_INPUT_YUV	= 3,
+};
+
+enum csi_output_raw {
+	CSI_OUTPUT_RAW_PASSTHROUGH = 0,
+};
+
+enum csi_output_yuv {
+	CSI_OUTPUT_YUV_422_PLANAR	= 0,
+	CSI_OUTPUT_YUV_420_PLANAR	= 1,
+	CSI_OUTPUT_YUV_422_UV		= 4,
+	CSI_OUTPUT_YUV_420_UV		= 5,
+	CSI_OUTPUT_YUV_422_MACRO	= 8,
+	CSI_OUTPUT_YUV_420_MACRO	= 9,
+};
+
+enum csi_yuv_data_seq {
+	CSI_YUV_DATA_SEQ_YUYV	= 0,
+	CSI_YUV_DATA_SEQ_YVYU	= 1,
+	CSI_YUV_DATA_SEQ_UYVY	= 2,
+	CSI_YUV_DATA_SEQ_VYUY	= 3,
+};
+
+enum csi_subdev_pads {
+	CSI_SUBDEV_SINK,
+	CSI_SUBDEV_SOURCE,
+
+	CSI_SUBDEV_PADS,
+};
+
+extern const struct v4l2_subdev_ops sun4i_csi_subdev_ops;
+
+struct sun4i_csi_format {
+	u32			mbus;
+	u32			fourcc;
+	enum csi_input		input;
+	u32			output;
+	unsigned int		num_planes;
+	u8			bpp[3];
+	unsigned int		hsub;
+	unsigned int		vsub;
+};
+
+const struct sun4i_csi_format *sun4i_csi_find_format(const u32 *fourcc,
+						     const u32 *mbus);
+
+struct sun4i_csi {
+	/* Device resources */
+	struct device			*dev;
+
+	void __iomem			*regs;
+	struct clk			*bus_clk;
+	struct clk			*isp_clk;
+	struct clk			*ram_clk;
+	struct reset_control		*rst;
+
+	struct vb2_v4l2_buffer		*current_buf[CSI_MAX_BUFFER];
+
+	struct {
+		size_t			size;
+		void			*vaddr;
+		dma_addr_t		paddr;
+	} scratch;
+
+	struct v4l2_fwnode_bus_parallel	bus;
+
+	/* Main Device */
+	struct v4l2_device		v4l;
+	struct media_device		mdev;
+	struct video_device		vdev;
+	struct media_pad		vdev_pad;
+	struct v4l2_pix_format_mplane	fmt;
+
+	/* Local subdev */
+	struct v4l2_subdev		subdev;
+	struct media_pad		subdev_pads[CSI_SUBDEV_PADS];
+	struct v4l2_mbus_framefmt	subdev_fmt;
+
+	/* V4L2 Async variables */
+	struct v4l2_async_subdev	asd;
+	struct v4l2_async_notifier	notifier;
+	struct v4l2_subdev		*src_subdev;
+	int				src_pad;
+
+	/* V4L2 variables */
+	struct mutex			lock;
+
+	/* Videobuf2 */
+	struct vb2_queue		queue;
+	struct list_head		buf_list;
+	spinlock_t			qlock;
+	unsigned int			sequence;
+};
+
+int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq);
+void sun4i_csi_dma_unregister(struct sun4i_csi *csi);
+
+int sun4i_csi_v4l2_register(struct sun4i_csi *csi);
+
+#endif /* _SUN4I_CSI_H_ */
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
new file mode 100644
index 000000000000..d6979e11a67b
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
@@ -0,0 +1,454 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <maxime.ripard@bootlin.com>
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun4i_csi.h"
+
+struct sun4i_csi_buffer {
+	struct vb2_v4l2_buffer	vb;
+	struct list_head	list;
+};
+
+static inline struct sun4i_csi_buffer *
+vb2_v4l2_to_csi_buffer(const struct vb2_v4l2_buffer *p)
+{
+	return container_of(p, struct sun4i_csi_buffer, vb);
+}
+
+static inline struct sun4i_csi_buffer *
+vb2_to_csi_buffer(const struct vb2_buffer *p)
+{
+	return vb2_v4l2_to_csi_buffer(to_vb2_v4l2_buffer(p));
+}
+
+static void sun4i_csi_capture_start(struct sun4i_csi *csi)
+{
+	writel(CSI_CPT_CTRL_VIDEO_START, csi->regs + CSI_CPT_CTRL_REG);
+}
+
+static void sun4i_csi_capture_stop(struct sun4i_csi *csi)
+{
+	writel(0, csi->regs + CSI_CPT_CTRL_REG);
+}
+
+static int sun4i_csi_queue_setup(struct vb2_queue *vq,
+				 unsigned int *nbuffers,
+				 unsigned int *nplanes,
+				 unsigned int sizes[],
+				 struct device *alloc_devs[])
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+	unsigned int num_planes = csi->fmt.num_planes;
+	unsigned int i;
+
+	if (*nplanes) {
+		if (*nplanes != num_planes)
+			return -EINVAL;
+
+		for (i = 0; i < num_planes; i++)
+			if (sizes[i] < csi->fmt.plane_fmt[i].sizeimage)
+				return -EINVAL;
+		return 0;
+	}
+
+	*nplanes = num_planes;
+	for (i = 0; i < num_planes; i++)
+		sizes[i] = csi->fmt.plane_fmt[i].sizeimage;
+
+	return 0;
+};
+
+static int sun4i_csi_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned int i;
+
+	for (i = 0; i < csi->fmt.num_planes; i++) {
+		unsigned long size = csi->fmt.plane_fmt[i].sizeimage;
+
+		if (vb2_plane_size(vb, i) < size) {
+			dev_err(csi->dev, "buffer too small (%lu < %lu)\n",
+				vb2_plane_size(vb, i), size);
+			return -EINVAL;
+		}
+
+		vb2_set_plane_payload(vb, i, size);
+	}
+
+	return 0;
+}
+
+static int sun4i_csi_setup_scratch_buffer(struct sun4i_csi *csi,
+					  unsigned int slot)
+{
+	dma_addr_t addr = csi->scratch.paddr;
+	unsigned int plane;
+
+	dev_dbg(csi->dev,
+		"No more available buffer, using the scratch buffer\n");
+
+	for (plane = 0; plane < csi->fmt.num_planes; plane++) {
+		writel(addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
+		addr += csi->fmt.plane_fmt[plane].sizeimage;
+	}
+
+	csi->current_buf[slot] = NULL;
+	return 0;
+}
+
+static int sun4i_csi_buffer_fill_slot(struct sun4i_csi *csi, unsigned int slot)
+{
+	struct sun4i_csi_buffer *c_buf;
+	struct vb2_v4l2_buffer *v_buf;
+	unsigned int plane;
+
+	/*
+	 * We should never end up in a situation where we overwrite an
+	 * already filled slot.
+	 */
+	if (WARN_ON(csi->current_buf[slot]))
+		return -EINVAL;
+
+	if (list_empty(&csi->buf_list))
+		return sun4i_csi_setup_scratch_buffer(csi, slot);
+
+	c_buf = list_first_entry(&csi->buf_list, struct sun4i_csi_buffer, list);
+	list_del_init(&c_buf->list);
+
+	v_buf = &c_buf->vb;
+	csi->current_buf[slot] = v_buf;
+
+	for (plane = 0; plane < csi->fmt.num_planes; plane++) {
+		dma_addr_t buf_addr;
+
+		buf_addr = vb2_dma_contig_plane_dma_addr(&v_buf->vb2_buf,
+							 plane);
+		writel(buf_addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
+	}
+
+	return 0;
+}
+
+static int sun4i_csi_buffer_fill_all(struct sun4i_csi *csi)
+{
+	unsigned int slot;
+	int ret;
+
+	for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
+		ret = sun4i_csi_buffer_fill_slot(csi, slot);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void sun4i_csi_buffer_mark_done(struct sun4i_csi *csi,
+				       unsigned int slot,
+				       unsigned int sequence)
+{
+	struct vb2_v4l2_buffer *v_buf;
+
+	if (!csi->current_buf[slot]) {
+		dev_dbg(csi->dev, "Scratch buffer was used, ignoring..\n");
+		return;
+	}
+
+	v_buf = csi->current_buf[slot];
+	v_buf->field = csi->fmt.field;
+	v_buf->sequence = sequence;
+	v_buf->vb2_buf.timestamp = ktime_get_ns();
+	vb2_buffer_done(&v_buf->vb2_buf, VB2_BUF_STATE_DONE);
+
+	csi->current_buf[slot] = NULL;
+}
+
+static int sun4i_csi_buffer_flip(struct sun4i_csi *csi, unsigned int sequence)
+{
+	u32 reg = readl(csi->regs + CSI_BUF_CTRL_REG);
+	unsigned int next;
+
+	/* Our next buffer is not the current buffer */
+	next = !(reg & CSI_BUF_CTRL_DBS);
+
+	/* Report the previous buffer as done */
+	sun4i_csi_buffer_mark_done(csi, next, sequence);
+
+	/* Put a new buffer in there */
+	return sun4i_csi_buffer_fill_slot(csi, next);
+}
+
+static void sun4i_csi_buffer_queue(struct vb2_buffer *vb)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
+	struct sun4i_csi_buffer *buf = vb2_to_csi_buffer(vb);
+	unsigned long flags;
+
+	spin_lock_irqsave(&csi->qlock, flags);
+	list_add_tail(&buf->list, &csi->buf_list);
+	spin_unlock_irqrestore(&csi->qlock, flags);
+}
+
+static void return_all_buffers(struct sun4i_csi *csi,
+			       enum vb2_buffer_state state)
+{
+	struct sun4i_csi_buffer *buf, *node;
+	unsigned int slot;
+
+	list_for_each_entry_safe(buf, node, &csi->buf_list, list) {
+		vb2_buffer_done(&buf->vb.vb2_buf, state);
+		list_del(&buf->list);
+	}
+
+	for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
+		struct vb2_v4l2_buffer *v_buf = csi->current_buf[slot];
+
+		if (!v_buf)
+			continue;
+
+		vb2_buffer_done(&v_buf->vb2_buf, state);
+		csi->current_buf[slot] = NULL;
+	}
+}
+
+static int sun4i_csi_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+	struct v4l2_fwnode_bus_parallel *bus = &csi->bus;
+	const struct sun4i_csi_format *csi_fmt;
+	unsigned long hsync_pol, pclk_pol, vsync_pol;
+	unsigned long flags;
+	unsigned int i;
+	int ret;
+
+	csi_fmt = sun4i_csi_find_format(&csi->fmt.pixelformat, NULL);
+	if (!csi_fmt)
+		return -EINVAL;
+
+	dev_dbg(csi->dev, "Starting capture\n");
+
+	csi->sequence = 0;
+
+	/*
+	 * We need a scratch buffer in case where we'll not have any
+	 * more buffer queued so that we don't error out. One of those
+	 * cases is when you end up at the last frame to capture, you
+	 * don't havea any buffer queued any more, and yet it doesn't
+	 * really matter since you'll never reach the next buffer.
+	 *
+	 * Since we support the multi-planar API, we need to have a
+	 * buffer for each plane. Allocating a single one large enough
+	 * to hold all the buffers is simpler, so let's go for that.
+	 */
+	csi->scratch.size = 0;
+	for (i = 0; i < csi->fmt.num_planes; i++)
+		csi->scratch.size += csi->fmt.plane_fmt[i].sizeimage;
+
+	csi->scratch.vaddr = dma_alloc_coherent(csi->dev,
+						csi->scratch.size,
+						&csi->scratch.paddr,
+						GFP_KERNEL);
+	if (!csi->scratch.vaddr) {
+		dev_err(csi->dev, "Failed to allocate scratch buffer\n");
+		ret = -ENOMEM;
+		goto err_clear_dma_queue;
+	}
+
+	ret = media_pipeline_start(&csi->vdev.entity, &csi->vdev.pipe);
+	if (ret < 0)
+		goto err_free_scratch_buffer;
+
+	spin_lock_irqsave(&csi->qlock, flags);
+
+	/* Setup timings */
+	writel(CSI_WIN_CTRL_W_ACTIVE(csi->fmt.width * 2),
+	       csi->regs + CSI_WIN_CTRL_W_REG);
+	writel(CSI_WIN_CTRL_H_ACTIVE(csi->fmt.height),
+	       csi->regs + CSI_WIN_CTRL_H_REG);
+
+	hsync_pol = !!(bus->flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH);
+	pclk_pol = !!(bus->flags & V4L2_MBUS_DATA_ACTIVE_HIGH);
+	vsync_pol = !!(bus->flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH);
+	writel(CSI_CFG_INPUT_FMT(csi_fmt->input) |
+	       CSI_CFG_OUTPUT_FMT(csi_fmt->output) |
+	       CSI_CFG_VSYNC_POL(vsync_pol) |
+	       CSI_CFG_HSYNC_POL(hsync_pol) |
+	       CSI_CFG_PCLK_POL(pclk_pol),
+	       csi->regs + CSI_CFG_REG);
+
+	/* Setup buffer length */
+	writel(csi->fmt.plane_fmt[0].bytesperline,
+	       csi->regs + CSI_BUF_LEN_REG);
+
+	/* Prepare our buffers in hardware */
+	ret = sun4i_csi_buffer_fill_all(csi);
+	if (ret) {
+		spin_unlock_irqrestore(&csi->qlock, flags);
+		goto err_disable_pipeline;
+	}
+
+	/* Enable double buffering */
+	writel(CSI_BUF_CTRL_DBE, csi->regs + CSI_BUF_CTRL_REG);
+
+	/* Clear the pending interrupts */
+	writel(CSI_INT_FRM_DONE, csi->regs + 0x34);
+
+	/* Enable frame done interrupt */
+	writel(CSI_INT_FRM_DONE, csi->regs + CSI_INT_EN_REG);
+
+	sun4i_csi_capture_start(csi);
+
+	spin_unlock_irqrestore(&csi->qlock, flags);
+
+	ret = v4l2_subdev_call(csi->src_subdev, video, s_stream, 1);
+	if (ret < 0 && ret != -ENOIOCTLCMD)
+		goto err_disable_device;
+
+	return 0;
+
+err_disable_device:
+	sun4i_csi_capture_stop(csi);
+
+err_disable_pipeline:
+	media_pipeline_stop(&csi->vdev.entity);
+
+err_free_scratch_buffer:
+	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
+			  csi->scratch.paddr);
+
+err_clear_dma_queue:
+	spin_lock_irqsave(&csi->qlock, flags);
+	return_all_buffers(csi, VB2_BUF_STATE_QUEUED);
+	spin_unlock_irqrestore(&csi->qlock, flags);
+
+	return ret;
+}
+
+static void sun4i_csi_stop_streaming(struct vb2_queue *vq)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+	unsigned long flags;
+
+	dev_dbg(csi->dev, "Stopping capture\n");
+
+	v4l2_subdev_call(csi->src_subdev, video, s_stream, 0);
+	sun4i_csi_capture_stop(csi);
+
+	/* Release all active buffers */
+	spin_lock_irqsave(&csi->qlock, flags);
+	return_all_buffers(csi, VB2_BUF_STATE_ERROR);
+	spin_unlock_irqrestore(&csi->qlock, flags);
+
+	media_pipeline_stop(&csi->vdev.entity);
+
+	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
+			  csi->scratch.paddr);
+}
+
+static const struct vb2_ops sun4i_csi_qops = {
+	.queue_setup		= sun4i_csi_queue_setup,
+	.buf_prepare		= sun4i_csi_buffer_prepare,
+	.buf_queue		= sun4i_csi_buffer_queue,
+	.start_streaming	= sun4i_csi_start_streaming,
+	.stop_streaming		= sun4i_csi_stop_streaming,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+};
+
+static irqreturn_t sun4i_csi_irq(int irq, void *data)
+{
+	struct sun4i_csi *csi = data;
+	u32 reg;
+
+	reg = readl(csi->regs + CSI_INT_STA_REG);
+
+	/* Acknowledge the interrupts */
+	writel(reg, csi->regs + CSI_INT_STA_REG);
+
+	if (!(reg & CSI_INT_FRM_DONE))
+		return IRQ_HANDLED;
+
+	spin_lock(&csi->qlock);
+	if (sun4i_csi_buffer_flip(csi, csi->sequence++)) {
+		dev_warn(csi->dev, "%s: Flip failed\n", __func__);
+		sun4i_csi_capture_stop(csi);
+	}
+	spin_unlock(&csi->qlock);
+
+	return IRQ_HANDLED;
+}
+
+int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq)
+{
+	struct vb2_queue *q = &csi->queue;
+	int ret;
+	int i;
+
+	spin_lock_init(&csi->qlock);
+	mutex_init(&csi->lock);
+
+	INIT_LIST_HEAD(&csi->buf_list);
+	for (i = 0; i < CSI_MAX_BUFFER; i++)
+		csi->current_buf[i] = NULL;
+
+	q->min_buffers_needed = 3;
+	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+	q->io_modes = VB2_MMAP;
+	q->lock = &csi->lock;
+	q->drv_priv = csi;
+	q->buf_struct_size = sizeof(struct sun4i_csi_buffer);
+	q->ops = &sun4i_csi_qops;
+	q->mem_ops = &vb2_dma_contig_memops;
+	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	q->dev = csi->dev;
+
+	ret = vb2_queue_init(q);
+	if (ret < 0) {
+		dev_err(csi->dev, "failed to initialize VB2 queue\n");
+		goto err_free_mutex;
+	}
+
+	ret = v4l2_device_register(csi->dev, &csi->v4l);
+	if (ret) {
+		dev_err(csi->dev, "Couldn't register the v4l2 device\n");
+		goto err_free_queue;
+	}
+
+	ret = devm_request_irq(csi->dev, irq, sun4i_csi_irq, 0,
+			       dev_name(csi->dev), csi);
+	if (ret) {
+		dev_err(csi->dev, "Couldn't register our interrupt\n");
+		goto err_unregister_device;
+	}
+
+	return 0;
+
+err_unregister_device:
+	v4l2_device_unregister(&csi->v4l);
+
+err_free_queue:
+	vb2_queue_release(q);
+
+err_free_mutex:
+	mutex_destroy(&csi->lock);
+	return ret;
+}
+
+void sun4i_csi_dma_unregister(struct sun4i_csi *csi)
+{
+	v4l2_device_unregister(&csi->v4l);
+	vb2_queue_release(&csi->queue);
+	mutex_destroy(&csi->lock);
+}
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
new file mode 100644
index 000000000000..772b0fc5920f
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
@@ -0,0 +1,385 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <maxime.ripard@bootlin.com>
+ */
+
+#include <linux/device.h>
+#include <linux/pm_runtime.h>
+
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun4i_csi.h"
+
+#define CSI_DEFAULT_WIDTH	640
+#define CSI_DEFAULT_HEIGHT	480
+
+const struct sun4i_csi_format sun4i_csi_formats[] = {
+	/* YUV422 inputs */
+	{
+		.mbus		= MEDIA_BUS_FMT_YUYV8_2X8,
+		.fourcc		= V4L2_PIX_FMT_YUV420M,
+		.input		= CSI_INPUT_YUV,
+		.output		= CSI_OUTPUT_YUV_420_PLANAR,
+		.num_planes	= 3,
+		.bpp		= { 8, 8, 8 },
+		.hsub		= 2,
+		.vsub		= 2,
+	},
+};
+
+const struct sun4i_csi_format *sun4i_csi_find_format(const u32 *fourcc,
+						     const u32 *mbus)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(sun4i_csi_formats); i++) {
+		if (fourcc && *fourcc != sun4i_csi_formats[i].fourcc)
+			continue;
+
+		if (mbus && *mbus != sun4i_csi_formats[i].mbus)
+			continue;
+
+		return &sun4i_csi_formats[i];
+	}
+
+	return NULL;
+}
+
+static int sun4i_csi_querycap(struct file *file, void *priv,
+			      struct v4l2_capability *cap)
+{
+	struct sun4i_csi *csi = video_drvdata(file);
+
+	strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
+	strscpy(cap->card, "sun4i-csi", sizeof(cap->card));
+	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
+		 dev_name(csi->dev));
+
+	return 0;
+}
+
+static int sun4i_csi_enum_input(struct file *file, void *priv,
+				struct v4l2_input *inp)
+{
+	if (inp->index != 0)
+		return -EINVAL;
+
+	inp->type = V4L2_INPUT_TYPE_CAMERA;
+	strscpy(inp->name, "Camera", sizeof(inp->name));
+
+	return 0;
+}
+
+static int sun4i_csi_g_input(struct file *file, void *fh,
+			     unsigned int *i)
+{
+	*i = 0;
+
+	return 0;
+}
+
+static int sun4i_csi_s_input(struct file *file, void *fh,
+			     unsigned int i)
+{
+	if (i != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void _sun4i_csi_try_fmt(struct sun4i_csi *csi,
+			       struct v4l2_pix_format_mplane *pix)
+{
+	const struct sun4i_csi_format *_fmt;
+	unsigned int height, width;
+	unsigned int i;
+
+	_fmt = sun4i_csi_find_format(&pix->pixelformat, NULL);
+	if (!_fmt)
+		_fmt = &sun4i_csi_formats[0];
+
+	pix->field = V4L2_FIELD_NONE;
+	pix->colorspace = V4L2_COLORSPACE_SRGB;
+	pix->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(pix->colorspace);
+	pix->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(pix->colorspace);
+	pix->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true, pix->colorspace,
+							  pix->ycbcr_enc);
+
+	pix->num_planes = _fmt->num_planes;
+	pix->pixelformat = _fmt->fourcc;
+
+	memset(pix->reserved, 0, sizeof(pix->reserved));
+
+	/* Align the width and height on the subsampling */
+	width = ALIGN(pix->width, _fmt->hsub);
+	height = ALIGN(pix->height, _fmt->vsub);
+
+	/* Clamp the width and height to our capabilities */
+	pix->width = clamp(width, _fmt->hsub, CSI_MAX_WIDTH);
+	pix->height = clamp(height, _fmt->vsub, CSI_MAX_HEIGHT);
+
+	for (i = 0; i < _fmt->num_planes; i++) {
+		unsigned int hsub = i > 0 ? _fmt->hsub : 1;
+		unsigned int vsub = i > 0 ? _fmt->vsub : 1;
+		unsigned int bpl;
+
+		bpl = pix->width / hsub * _fmt->bpp[i] / 8;
+		pix->plane_fmt[i].bytesperline = bpl;
+		pix->plane_fmt[i].sizeimage = bpl * pix->height / vsub;
+		memset(pix->plane_fmt[i].reserved, 0,
+		       sizeof(pix->plane_fmt[i].reserved));
+	}
+}
+
+static int sun4i_csi_try_fmt_vid_cap(struct file *file, void *priv,
+				     struct v4l2_format *f)
+{
+	struct sun4i_csi *csi = video_drvdata(file);
+
+	_sun4i_csi_try_fmt(csi, &f->fmt.pix_mp);
+
+	return 0;
+}
+
+static int sun4i_csi_s_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_format *f)
+{
+	struct sun4i_csi *csi = video_drvdata(file);
+
+	_sun4i_csi_try_fmt(csi, &f->fmt.pix_mp);
+	csi->fmt = f->fmt.pix_mp;
+
+	return 0;
+}
+
+static int sun4i_csi_g_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_format *f)
+{
+	struct sun4i_csi *csi = video_drvdata(file);
+
+	f->fmt.pix_mp = csi->fmt;
+
+	return 0;
+}
+
+static int sun4i_csi_enum_fmt_vid_cap(struct file *file, void *priv,
+				      struct v4l2_fmtdesc *f)
+{
+	if (f->index >= ARRAY_SIZE(sun4i_csi_formats))
+		return -EINVAL;
+
+	f->pixelformat = sun4i_csi_formats[f->index].fourcc;
+
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops sun4i_csi_ioctl_ops = {
+	.vidioc_querycap		= sun4i_csi_querycap,
+
+	.vidioc_enum_fmt_vid_cap	= sun4i_csi_enum_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap_mplane	= sun4i_csi_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap_mplane	= sun4i_csi_s_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap_mplane	= sun4i_csi_try_fmt_vid_cap,
+
+	.vidioc_enum_input		= sun4i_csi_enum_input,
+	.vidioc_g_input			= sun4i_csi_g_input,
+	.vidioc_s_input			= sun4i_csi_s_input,
+
+	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
+	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
+	.vidioc_querybuf		= vb2_ioctl_querybuf,
+	.vidioc_qbuf			= vb2_ioctl_qbuf,
+	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
+	.vidioc_expbuf			= vb2_ioctl_expbuf,
+	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
+	.vidioc_streamon		= vb2_ioctl_streamon,
+	.vidioc_streamoff		= vb2_ioctl_streamoff,
+};
+
+static int sun4i_csi_open(struct file *file)
+{
+	struct sun4i_csi *csi = video_drvdata(file);
+	int ret;
+
+	ret = mutex_lock_interruptible(&csi->lock);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_get_sync(csi->dev);
+	if (ret < 0)
+		goto err_pm_put;
+
+	ret = v4l2_pipeline_pm_use(&csi->vdev.entity, 1);
+	if (ret)
+		goto err_pm_put;
+
+	ret = v4l2_fh_open(file);
+	if (ret)
+		goto err_pipeline_pm_put;
+
+	mutex_unlock(&csi->lock);
+
+	return 0;
+
+err_pipeline_pm_put:
+	v4l2_pipeline_pm_use(&csi->vdev.entity, 0);
+
+err_pm_put:
+	pm_runtime_put(csi->dev);
+	mutex_unlock(&csi->lock);
+
+	return ret;
+}
+
+static int sun4i_csi_release(struct file *file)
+{
+	struct sun4i_csi *csi = video_drvdata(file);
+
+	mutex_lock(&csi->lock);
+
+	v4l2_fh_release(file);
+	v4l2_pipeline_pm_use(&csi->vdev.entity, 0);
+	pm_runtime_put(csi->dev);
+
+	mutex_unlock(&csi->lock);
+
+	return 0;
+}
+
+static const struct v4l2_file_operations sun4i_csi_fops = {
+	.owner		= THIS_MODULE,
+	.open		= sun4i_csi_open,
+	.release	= sun4i_csi_release,
+	.unlocked_ioctl	= video_ioctl2,
+	.read		= vb2_fop_read,
+	.write		= vb2_fop_write,
+	.poll		= vb2_fop_poll,
+	.mmap		= vb2_fop_mmap,
+};
+
+static const struct v4l2_mbus_framefmt sun4i_csi_pad_fmt_default = {
+	.width = CSI_DEFAULT_WIDTH,
+	.height = CSI_DEFAULT_HEIGHT,
+	.code = MEDIA_BUS_FMT_YUYV8_2X8,
+	.field = V4L2_FIELD_NONE,
+	.colorspace = V4L2_COLORSPACE_RAW,
+	.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT,
+	.quantization = V4L2_QUANTIZATION_DEFAULT,
+	.xfer_func = V4L2_XFER_FUNC_DEFAULT,
+};
+
+static int sun4i_csi_subdev_init_cfg(struct v4l2_subdev *subdev,
+				     struct v4l2_subdev_pad_config *cfg)
+{
+	struct v4l2_mbus_framefmt *fmt;
+
+	fmt = v4l2_subdev_get_try_format(subdev, cfg, CSI_SUBDEV_SINK);
+	*fmt = sun4i_csi_pad_fmt_default;
+
+	return 0;
+}
+
+static int sun4i_csi_subdev_get_fmt(struct v4l2_subdev *subdev,
+				    struct v4l2_subdev_pad_config *cfg,
+				    struct v4l2_subdev_format *fmt)
+{
+	struct sun4i_csi *csi = container_of(subdev, struct sun4i_csi, subdev);
+	struct v4l2_mbus_framefmt *subdev_fmt;
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
+		subdev_fmt = v4l2_subdev_get_try_format(subdev, cfg, fmt->pad);
+	else
+		subdev_fmt = &csi->subdev_fmt;
+
+	fmt->format = *subdev_fmt;
+
+	return 0;
+}
+
+static int sun4i_csi_subdev_set_fmt(struct v4l2_subdev *subdev,
+				    struct v4l2_subdev_pad_config *cfg,
+				    struct v4l2_subdev_format *fmt)
+{
+	struct sun4i_csi *csi = container_of(subdev, struct sun4i_csi, subdev);
+	struct v4l2_mbus_framefmt *subdev_fmt;
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
+		subdev_fmt = v4l2_subdev_get_try_format(subdev, cfg, fmt->pad);
+	else
+		subdev_fmt = &csi->subdev_fmt;
+
+	/* We can only set the format on the sink pad */
+	if (fmt->pad == CSI_SUBDEV_SINK) {
+		/* It's the sink, only allow changing the frame size */
+		subdev_fmt->width = fmt->format.width;
+		subdev_fmt->height = fmt->format.height;
+		subdev_fmt->code = fmt->format.code;
+	}
+
+	fmt->format = *subdev_fmt;
+
+	return 0;
+}
+
+static int
+sun4i_csi_subdev_enum_mbus_code(struct v4l2_subdev *subdev,
+				struct v4l2_subdev_pad_config *cfg,
+				struct v4l2_subdev_mbus_code_enum *mbus)
+{
+	if (mbus->index >= ARRAY_SIZE(sun4i_csi_formats))
+		return -EINVAL;
+
+	mbus->code = sun4i_csi_formats[mbus->index].mbus;
+
+	return 0;
+}
+
+static const struct v4l2_subdev_pad_ops sun4i_csi_subdev_pad_ops = {
+	.link_validate	= v4l2_subdev_link_validate_default,
+	.init_cfg	= sun4i_csi_subdev_init_cfg,
+	.get_fmt	= sun4i_csi_subdev_get_fmt,
+	.set_fmt	= sun4i_csi_subdev_set_fmt,
+	.enum_mbus_code	= sun4i_csi_subdev_enum_mbus_code,
+};
+
+const struct v4l2_subdev_ops sun4i_csi_subdev_ops = {
+	.pad = &sun4i_csi_subdev_pad_ops,
+};
+
+int sun4i_csi_v4l2_register(struct sun4i_csi *csi)
+{
+	struct video_device *vdev = &csi->vdev;
+	int ret;
+
+	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_STREAMING;
+	vdev->v4l2_dev = &csi->v4l;
+	vdev->queue = &csi->queue;
+	strscpy(vdev->name, KBUILD_MODNAME, sizeof(vdev->name));
+	vdev->release = video_device_release_empty;
+	vdev->lock = &csi->lock;
+
+	/* Set a default format */
+	csi->fmt.pixelformat = sun4i_csi_formats[0].fourcc,
+	csi->fmt.width = CSI_DEFAULT_WIDTH;
+	csi->fmt.height = CSI_DEFAULT_HEIGHT;
+	_sun4i_csi_try_fmt(csi, &csi->fmt);
+	csi->subdev_fmt = sun4i_csi_pad_fmt_default;
+
+	vdev->fops = &sun4i_csi_fops;
+	vdev->ioctl_ops = &sun4i_csi_ioctl_ops;
+	video_set_drvdata(vdev, csi);
+
+	ret = video_register_device(&csi->vdev, VFL_TYPE_GRABBER, -1);
+	if (ret)
+		return ret;
+
+	dev_info(csi->dev, "Device registered as %s\n",
+		 video_device_node_name(vdev));
+
+	return 0;
+}