media: sun6i: Add support for Allwinner CSI V3s

Allwinner V3s SoC features a CSI module with parallel interface.

This patch implement a v4l2 framework driver for it.
Reviewed-by: NHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: NMaxime Ripard <maxime.ripard@bootlin.com>
Tested-by: NMaxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: NYong Deng <yong.deng@magewell.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/Kconfig

@@ -138,6 +138,7 @@ source "drivers/media/platform/am437x/Kconfig"
 source "drivers/media/platform/xilinx/Kconfig"
 source "drivers/media/platform/rcar-vin/Kconfig"
 source "drivers/media/platform/atmel/Kconfig"
+source "drivers/media/platform/sunxi/sun6i-csi/Kconfig"
 
 config VIDEO_TI_CAL
 	tristate "TI CAL (Camera Adaptation Layer) driver"

drivers/media/platform/Makefile

@@ -100,3 +100,5 @@ obj-$(CONFIG_VIDEO_QCOM_VENUS)		+= qcom/venus/
 obj-y					+= meson/
 
 obj-y					+= cros-ec-cec/
+
+obj-$(CONFIG_VIDEO_SUN6I_CSI)		+= sunxi/sun6i-csi/

drivers/media/platform/sunxi/sun6i-csi/Kconfig

+config VIDEO_SUN6I_CSI
+	tristate "Allwinner V3s Camera Sensor Interface driver"
+	depends on VIDEO_V4L2 && COMMON_CLK && VIDEO_V4L2_SUBDEV_API && HAS_DMA
+	depends on ARCH_SUNXI || COMPILE_TEST
+	select VIDEOBUF2_DMA_CONTIG
+	select REGMAP_MMIO
+	select V4L2_FWNODE
+	help
+	   Support for the Allwinner Camera Sensor Interface Controller on V3s.

drivers/media/platform/sunxi/sun6i-csi/Makefile

+sun6i-csi-y += sun6i_video.o sun6i_csi.o
+
+obj-$(CONFIG_VIDEO_SUN6I_CSI) += sun6i-csi.o

drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <yong.deng@magewell.com>
+ */
+
+#ifndef __SUN6I_CSI_H__
+#define __SUN6I_CSI_H__
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+
+#include "sun6i_video.h"
+
+struct sun6i_csi;
+
+/**
+ * struct sun6i_csi_config - configs for sun6i csi
+ * @pixelformat: v4l2 pixel format (V4L2_PIX_FMT_*)
+ * @code:	media bus format code (MEDIA_BUS_FMT_*)
+ * @field:	used interlacing type (enum v4l2_field)
+ * @width:	frame width
+ * @height:	frame height
+ */
+struct sun6i_csi_config {
+	u32		pixelformat;
+	u32		code;
+	u32		field;
+	u32		width;
+	u32		height;
+};
+
+struct sun6i_csi {
+	struct device			*dev;
+	struct v4l2_ctrl_handler	ctrl_handler;
+	struct v4l2_device		v4l2_dev;
+	struct media_device		media_dev;
+
+	struct v4l2_async_notifier	notifier;
+
+	/* video port settings */
+	struct v4l2_fwnode_endpoint	v4l2_ep;
+
+	struct sun6i_csi_config		config;
+
+	struct sun6i_video		video;
+};
+
+/**
+ * sun6i_csi_is_format_supported() - check if the format supported by csi
+ * @csi:	pointer to the csi
+ * @pixformat:	v4l2 pixel format (V4L2_PIX_FMT_*)
+ * @mbus_code:	media bus format code (MEDIA_BUS_FMT_*)
+ */
+bool sun6i_csi_is_format_supported(struct sun6i_csi *csi, u32 pixformat,
+				 u32 mbus_code);
+
+/**
+ * sun6i_csi_set_power() - power on/off the csi
+ * @csi:	pointer to the csi
+ * @enable:	on/off
+ */
+int sun6i_csi_set_power(struct sun6i_csi *csi, bool enable);
+
+/**
+ * sun6i_csi_update_config() - update the csi register setttings
+ * @csi:	pointer to the csi
+ * @config:	see struct sun6i_csi_config
+ */
+int sun6i_csi_update_config(struct sun6i_csi *csi,
+			    struct sun6i_csi_config *config);
+
+/**
+ * sun6i_csi_update_buf_addr() - update the csi frame buffer address
+ * @csi:	pointer to the csi
+ * @addr:	frame buffer's physical address
+ */
+void sun6i_csi_update_buf_addr(struct sun6i_csi *csi, dma_addr_t addr);
+
+/**
+ * sun6i_csi_set_stream() - start/stop csi streaming
+ * @csi:	pointer to the csi
+ * @enable:	start/stop
+ */
+void sun6i_csi_set_stream(struct sun6i_csi *csi, bool enable);
+
+/* get bpp form v4l2 pixformat */
+static inline int sun6i_csi_get_bpp(unsigned int pixformat)
+{
+	switch (pixformat) {
+	case V4L2_PIX_FMT_SBGGR8:
+	case V4L2_PIX_FMT_SGBRG8:
+	case V4L2_PIX_FMT_SGRBG8:
+	case V4L2_PIX_FMT_SRGGB8:
+		return 8;
+	case V4L2_PIX_FMT_SBGGR10:
+	case V4L2_PIX_FMT_SGBRG10:
+	case V4L2_PIX_FMT_SGRBG10:
+	case V4L2_PIX_FMT_SRGGB10:
+		return 10;
+	case V4L2_PIX_FMT_SBGGR12:
+	case V4L2_PIX_FMT_SGBRG12:
+	case V4L2_PIX_FMT_SGRBG12:
+	case V4L2_PIX_FMT_SRGGB12:
+	case V4L2_PIX_FMT_HM12:
+	case V4L2_PIX_FMT_NV12:
+	case V4L2_PIX_FMT_NV21:
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YVU420:
+		return 12;
+	case V4L2_PIX_FMT_YUYV:
+	case V4L2_PIX_FMT_YVYU:
+	case V4L2_PIX_FMT_UYVY:
+	case V4L2_PIX_FMT_VYUY:
+	case V4L2_PIX_FMT_NV16:
+	case V4L2_PIX_FMT_NV61:
+	case V4L2_PIX_FMT_YUV422P:
+		return 16;
+	case V4L2_PIX_FMT_RGB24:
+	case V4L2_PIX_FMT_BGR24:
+		return 24;
+	case V4L2_PIX_FMT_RGB32:
+	case V4L2_PIX_FMT_BGR32:
+		return 32;
+	default:
+		WARN(1, "Unsupported pixformat: 0x%x\n", pixformat);
+		break;
+	}
+
+	return 0;
+}
+
+#endif /* __SUN6I_CSI_H__ */

drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_reg.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <yong.deng@magewell.com>
+ */
+
+#ifndef __SUN6I_CSI_REG_H__
+#define __SUN6I_CSI_REG_H__
+
+#include <linux/kernel.h>
+
+#define CSI_EN_REG			0x0
+#define CSI_EN_VER_EN				BIT(30)
+#define CSI_EN_CSI_EN				BIT(0)
+
+#define CSI_IF_CFG_REG			0x4
+#define CSI_IF_CFG_SRC_TYPE_MASK		BIT(21)
+#define CSI_IF_CFG_SRC_TYPE_PROGRESSED		((0 << 21) & CSI_IF_CFG_SRC_TYPE_MASK)
+#define CSI_IF_CFG_SRC_TYPE_INTERLACED		((1 << 21) & CSI_IF_CFG_SRC_TYPE_MASK)
+#define CSI_IF_CFG_FPS_DS_EN			BIT(20)
+#define CSI_IF_CFG_FIELD_MASK			BIT(19)
+#define CSI_IF_CFG_FIELD_NEGATIVE		((0 << 19) & CSI_IF_CFG_FIELD_MASK)
+#define CSI_IF_CFG_FIELD_POSITIVE		((1 << 19) & CSI_IF_CFG_FIELD_MASK)
+#define CSI_IF_CFG_VREF_POL_MASK		BIT(18)
+#define CSI_IF_CFG_VREF_POL_NEGATIVE		((0 << 18) & CSI_IF_CFG_VREF_POL_MASK)
+#define CSI_IF_CFG_VREF_POL_POSITIVE		((1 << 18) & CSI_IF_CFG_VREF_POL_MASK)
+#define CSI_IF_CFG_HREF_POL_MASK		BIT(17)
+#define CSI_IF_CFG_HREF_POL_NEGATIVE		((0 << 17) & CSI_IF_CFG_HREF_POL_MASK)
+#define CSI_IF_CFG_HREF_POL_POSITIVE		((1 << 17) & CSI_IF_CFG_HREF_POL_MASK)
+#define CSI_IF_CFG_CLK_POL_MASK			BIT(16)
+#define CSI_IF_CFG_CLK_POL_RISING_EDGE		((0 << 16) & CSI_IF_CFG_CLK_POL_MASK)
+#define CSI_IF_CFG_CLK_POL_FALLING_EDGE		((1 << 16) & CSI_IF_CFG_CLK_POL_MASK)
+#define CSI_IF_CFG_IF_DATA_WIDTH_MASK		GENMASK(10, 8)
+#define CSI_IF_CFG_IF_DATA_WIDTH_8BIT		((0 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
+#define CSI_IF_CFG_IF_DATA_WIDTH_10BIT		((1 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
+#define CSI_IF_CFG_IF_DATA_WIDTH_12BIT		((2 << 8) & CSI_IF_CFG_IF_DATA_WIDTH_MASK)
+#define CSI_IF_CFG_MIPI_IF_MASK			BIT(7)
+#define CSI_IF_CFG_MIPI_IF_CSI			(0 << 7)
+#define CSI_IF_CFG_MIPI_IF_MIPI			(1 << 7)
+#define CSI_IF_CFG_CSI_IF_MASK			GENMASK(4, 0)
+#define CSI_IF_CFG_CSI_IF_YUV422_INTLV		((0 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+#define CSI_IF_CFG_CSI_IF_YUV422_16BIT		((1 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+#define CSI_IF_CFG_CSI_IF_BT656			((4 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+#define CSI_IF_CFG_CSI_IF_BT1120		((5 << 0) & CSI_IF_CFG_CSI_IF_MASK)
+
+#define CSI_CAP_REG			0x8
+#define CSI_CAP_CH0_CAP_MASK_MASK		GENMASK(5, 2)
+#define CSI_CAP_CH0_CAP_MASK(count)		((count << 2) & CSI_CAP_CH0_CAP_MASK_MASK)
+#define CSI_CAP_CH0_VCAP_ON			BIT(1)
+#define CSI_CAP_CH0_SCAP_ON			BIT(0)
+
+#define CSI_SYNC_CNT_REG		0xc
+#define CSI_FIFO_THRS_REG		0x10
+#define CSI_BT656_HEAD_CFG_REG		0x14
+#define CSI_PTN_LEN_REG			0x30
+#define CSI_PTN_ADDR_REG		0x34
+#define CSI_VER_REG			0x3c
+
+#define CSI_CH_CFG_REG			0x44
+#define CSI_CH_CFG_INPUT_FMT_MASK		GENMASK(23, 20)
+#define CSI_CH_CFG_INPUT_FMT(fmt)		((fmt << 20) & CSI_CH_CFG_INPUT_FMT_MASK)
+#define CSI_CH_CFG_OUTPUT_FMT_MASK		GENMASK(19, 16)
+#define CSI_CH_CFG_OUTPUT_FMT(fmt)		((fmt << 16) & CSI_CH_CFG_OUTPUT_FMT_MASK)
+#define CSI_CH_CFG_VFLIP_EN			BIT(13)
+#define CSI_CH_CFG_HFLIP_EN			BIT(12)
+#define CSI_CH_CFG_FIELD_SEL_MASK		GENMASK(11, 10)
+#define CSI_CH_CFG_FIELD_SEL_FIELD0		((0 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
+#define CSI_CH_CFG_FIELD_SEL_FIELD1		((1 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
+#define CSI_CH_CFG_FIELD_SEL_BOTH		((2 << 10) & CSI_CH_CFG_FIELD_SEL_MASK)
+#define CSI_CH_CFG_INPUT_SEQ_MASK		GENMASK(9, 8)
+#define CSI_CH_CFG_INPUT_SEQ(seq)		((seq << 8) & CSI_CH_CFG_INPUT_SEQ_MASK)
+
+#define CSI_CH_SCALE_REG		0x4c
+#define CSI_CH_SCALE_QUART_EN			BIT(0)
+
+#define CSI_CH_F0_BUFA_REG		0x50
+
+#define CSI_CH_F1_BUFA_REG		0x58
+
+#define CSI_CH_F2_BUFA_REG		0x60
+
+#define CSI_CH_STA_REG			0x6c
+#define CSI_CH_STA_FIELD_STA_MASK		BIT(2)
+#define CSI_CH_STA_FIELD_STA_FIELD0		((0 << 2) & CSI_CH_STA_FIELD_STA_MASK)
+#define CSI_CH_STA_FIELD_STA_FIELD1		((1 << 2) & CSI_CH_STA_FIELD_STA_MASK)
+#define CSI_CH_STA_VCAP_STA			BIT(1)
+#define CSI_CH_STA_SCAP_STA			BIT(0)
+
+#define CSI_CH_INT_EN_REG		0x70
+#define CSI_CH_INT_EN_VS_INT_EN			BIT(7)
+#define CSI_CH_INT_EN_HB_OF_INT_EN		BIT(6)
+#define CSI_CH_INT_EN_MUL_ERR_INT_EN		BIT(5)
+#define CSI_CH_INT_EN_FIFO2_OF_INT_EN		BIT(4)
+#define CSI_CH_INT_EN_FIFO1_OF_INT_EN		BIT(3)
+#define CSI_CH_INT_EN_FIFO0_OF_INT_EN		BIT(2)
+#define CSI_CH_INT_EN_FD_INT_EN			BIT(1)
+#define CSI_CH_INT_EN_CD_INT_EN			BIT(0)
+
+#define CSI_CH_INT_STA_REG		0x74
+#define CSI_CH_INT_STA_VS_PD			BIT(7)
+#define CSI_CH_INT_STA_HB_OF_PD			BIT(6)
+#define CSI_CH_INT_STA_MUL_ERR_PD		BIT(5)
+#define CSI_CH_INT_STA_FIFO2_OF_PD		BIT(4)
+#define CSI_CH_INT_STA_FIFO1_OF_PD		BIT(3)
+#define CSI_CH_INT_STA_FIFO0_OF_PD		BIT(2)
+#define CSI_CH_INT_STA_FD_PD			BIT(1)
+#define CSI_CH_INT_STA_CD_PD			BIT(0)
+
+#define CSI_CH_FLD1_VSIZE_REG		0x78
+
+#define CSI_CH_HSIZE_REG		0x80
+#define CSI_CH_HSIZE_HOR_LEN_MASK		GENMASK(28, 16)
+#define CSI_CH_HSIZE_HOR_LEN(len)		((len << 16) & CSI_CH_HSIZE_HOR_LEN_MASK)
+#define CSI_CH_HSIZE_HOR_START_MASK		GENMASK(12, 0)
+#define CSI_CH_HSIZE_HOR_START(start)		((start << 0) & CSI_CH_HSIZE_HOR_START_MASK)
+
+#define CSI_CH_VSIZE_REG		0x84
+#define CSI_CH_VSIZE_VER_LEN_MASK		GENMASK(28, 16)
+#define CSI_CH_VSIZE_VER_LEN(len)		((len << 16) & CSI_CH_VSIZE_VER_LEN_MASK)
+#define CSI_CH_VSIZE_VER_START_MASK		GENMASK(12, 0)
+#define CSI_CH_VSIZE_VER_START(start)		((start << 0) & CSI_CH_VSIZE_VER_START_MASK)
+
+#define CSI_CH_BUF_LEN_REG		0x88
+#define CSI_CH_BUF_LEN_BUF_LEN_C_MASK		GENMASK(29, 16)
+#define CSI_CH_BUF_LEN_BUF_LEN_C(len)		((len << 16) & CSI_CH_BUF_LEN_BUF_LEN_C_MASK)
+#define CSI_CH_BUF_LEN_BUF_LEN_Y_MASK		GENMASK(13, 0)
+#define CSI_CH_BUF_LEN_BUF_LEN_Y(len)		((len << 0) & CSI_CH_BUF_LEN_BUF_LEN_Y_MASK)
+
+#define CSI_CH_FLIP_SIZE_REG		0x8c
+#define CSI_CH_FLIP_SIZE_VER_LEN_MASK		GENMASK(28, 16)
+#define CSI_CH_FLIP_SIZE_VER_LEN(len)		((len << 16) & CSI_CH_FLIP_SIZE_VER_LEN_MASK)
+#define CSI_CH_FLIP_SIZE_VALID_LEN_MASK		GENMASK(12, 0)
+#define CSI_CH_FLIP_SIZE_VALID_LEN(len)		((len << 0) & CSI_CH_FLIP_SIZE_VALID_LEN_MASK)
+
+#define CSI_CH_FRM_CLK_CNT_REG		0x90
+#define CSI_CH_ACC_ITNL_CLK_CNT_REG	0x94
+#define CSI_CH_FIFO_STAT_REG		0x98
+#define CSI_CH_PCLK_STAT_REG		0x9c
+
+/*
+ * csi input data format
+ */
+enum csi_input_fmt {
+	CSI_INPUT_FORMAT_RAW		= 0,
+	CSI_INPUT_FORMAT_YUV422		= 3,
+	CSI_INPUT_FORMAT_YUV420		= 4,
+};
+
+/*
+ * csi output data format
+ */
+enum csi_output_fmt {
+	/* only when input format is RAW */
+	CSI_FIELD_RAW_8			= 0,
+	CSI_FIELD_RAW_10		= 1,
+	CSI_FIELD_RAW_12		= 2,
+	CSI_FIELD_RGB565		= 4,
+	CSI_FIELD_RGB888		= 5,
+	CSI_FIELD_PRGB888		= 6,
+	CSI_FRAME_RAW_8			= 8,
+	CSI_FRAME_RAW_10		= 9,
+	CSI_FRAME_RAW_12		= 10,
+	CSI_FRAME_RGB565		= 12,
+	CSI_FRAME_RGB888		= 13,
+	CSI_FRAME_PRGB888		= 14,
+
+	/* only when input format is YUV422 */
+	CSI_FIELD_PLANAR_YUV422		= 0,
+	CSI_FIELD_PLANAR_YUV420		= 1,
+	CSI_FRAME_PLANAR_YUV420		= 2,
+	CSI_FRAME_PLANAR_YUV422		= 3,
+	CSI_FIELD_UV_CB_YUV422		= 4,
+	CSI_FIELD_UV_CB_YUV420		= 5,
+	CSI_FRAME_UV_CB_YUV420		= 6,
+	CSI_FRAME_UV_CB_YUV422		= 7,
+	CSI_FIELD_MB_YUV422		= 8,
+	CSI_FIELD_MB_YUV420		= 9,
+	CSI_FRAME_MB_YUV420		= 10,
+	CSI_FRAME_MB_YUV422		= 11,
+	CSI_FIELD_UV_CB_YUV422_10	= 12,
+	CSI_FIELD_UV_CB_YUV420_10	= 13,
+};
+
+/*
+ * csi YUV input data sequence
+ */
+enum csi_input_seq {
+	/* only when input format is YUV422 */
+	CSI_INPUT_SEQ_YUYV = 0,
+	CSI_INPUT_SEQ_YVYU,
+	CSI_INPUT_SEQ_UYVY,
+	CSI_INPUT_SEQ_VYUY,
+};
+
+#endif /* __SUN6I_CSI_REG_H__ */

drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <yong.deng@magewell.com>
+ */
+
+#include <linux/of.h>
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun6i_csi.h"
+#include "sun6i_video.h"
+
+/* This is got from BSP sources. */
+#define MIN_WIDTH	(32)
+#define MIN_HEIGHT	(32)
+#define MAX_WIDTH	(4800)
+#define MAX_HEIGHT	(4800)
+
+struct sun6i_csi_buffer {
+	struct vb2_v4l2_buffer		vb;
+	struct list_head		list;
+
+	dma_addr_t			dma_addr;
+	bool				queued_to_csi;
+};
+
+static const u32 supported_pixformats[] = {
+	V4L2_PIX_FMT_SBGGR8,
+	V4L2_PIX_FMT_SGBRG8,
+	V4L2_PIX_FMT_SGRBG8,
+	V4L2_PIX_FMT_SRGGB8,
+	V4L2_PIX_FMT_SBGGR10,
+	V4L2_PIX_FMT_SGBRG10,
+	V4L2_PIX_FMT_SGRBG10,
+	V4L2_PIX_FMT_SRGGB10,
+	V4L2_PIX_FMT_SBGGR12,
+	V4L2_PIX_FMT_SGBRG12,
+	V4L2_PIX_FMT_SGRBG12,
+	V4L2_PIX_FMT_SRGGB12,
+	V4L2_PIX_FMT_YUYV,
+	V4L2_PIX_FMT_YVYU,
+	V4L2_PIX_FMT_UYVY,
+	V4L2_PIX_FMT_VYUY,
+	V4L2_PIX_FMT_HM12,
+	V4L2_PIX_FMT_NV12,
+	V4L2_PIX_FMT_NV21,
+	V4L2_PIX_FMT_YUV420,
+	V4L2_PIX_FMT_YVU420,
+	V4L2_PIX_FMT_NV16,
+	V4L2_PIX_FMT_NV61,
+	V4L2_PIX_FMT_YUV422P,
+};
+
+static bool is_pixformat_valid(unsigned int pixformat)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(supported_pixformats); i++)
+		if (supported_pixformats[i] == pixformat)
+			return true;
+
+	return false;
+}
+
+static struct v4l2_subdev *
+sun6i_video_remote_subdev(struct sun6i_video *video, u32 *pad)
+{
+	struct media_pad *remote;
+
+	remote = media_entity_remote_pad(&video->pad);
+
+	if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
+		return NULL;
+
+	if (pad)
+		*pad = remote->index;
+
+	return media_entity_to_v4l2_subdev(remote->entity);
+}
+
+static int sun6i_video_queue_setup(struct vb2_queue *vq,
+				 unsigned int *nbuffers, unsigned int *nplanes,
+				 unsigned int sizes[],
+				 struct device *alloc_devs[])
+{
+	struct sun6i_video *video = vb2_get_drv_priv(vq);
+	unsigned int size = video->fmt.fmt.pix.sizeimage;
+
+	if (*nplanes)
+		return sizes[0] < size ? -EINVAL : 0;
+
+	*nplanes = 1;
+	sizes[0] = size;
+
+	return 0;
+}
+
+static int sun6i_video_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct sun6i_csi_buffer *buf =
+			container_of(vbuf, struct sun6i_csi_buffer, vb);
+	struct sun6i_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long size = video->fmt.fmt.pix.sizeimage;
+
+	if (vb2_plane_size(vb, 0) < size) {
+		v4l2_err(video->vdev.v4l2_dev, "buffer too small (%lu < %lu)\n",
+			 vb2_plane_size(vb, 0), size);
+		return -EINVAL;
+	}
+
+	vb2_set_plane_payload(vb, 0, size);
+
+	buf->dma_addr = vb2_dma_contig_plane_dma_addr(vb, 0);
+
+	vbuf->field = video->fmt.fmt.pix.field;
+
+	return 0;
+}
+
+static int sun6i_video_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct sun6i_video *video = vb2_get_drv_priv(vq);
+	struct sun6i_csi_buffer *buf;
+	struct sun6i_csi_buffer *next_buf;
+	struct sun6i_csi_config config;
+	struct v4l2_subdev *subdev;
+	unsigned long flags;
+	int ret;
+
+	video->sequence = 0;
+
+	ret = media_pipeline_start(&video->vdev.entity, &video->vdev.pipe);
+	if (ret < 0)
+		goto clear_dma_queue;
+
+	if (video->mbus_code == 0) {
+		ret = -EINVAL;
+		goto stop_media_pipeline;
+	}
+
+	subdev = sun6i_video_remote_subdev(video, NULL);
+	if (!subdev)
+		goto stop_media_pipeline;
+
+	config.pixelformat = video->fmt.fmt.pix.pixelformat;
+	config.code = video->mbus_code;
+	config.field = video->fmt.fmt.pix.field;
+	config.width = video->fmt.fmt.pix.width;
+	config.height = video->fmt.fmt.pix.height;
+
+	ret = sun6i_csi_update_config(video->csi, &config);
+	if (ret < 0)
+		goto stop_media_pipeline;
+
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+
+	buf = list_first_entry(&video->dma_queue,
+			       struct sun6i_csi_buffer, list);
+	buf->queued_to_csi = true;
+	sun6i_csi_update_buf_addr(video->csi, buf->dma_addr);
+
+	sun6i_csi_set_stream(video->csi, true);
+
+	/*
+	 * CSI will lookup the next dma buffer for next frame before the
+	 * the current frame done IRQ triggered. This is not documented
+	 * but reported by Ondřej Jirman.
+	 * The BSP code has workaround for this too. It skip to mark the
+	 * first buffer as frame done for VB2 and pass the second buffer
+	 * to CSI in the first frame done ISR call. Then in second frame
+	 * done ISR call, it mark the first buffer as frame done for VB2
+	 * and pass the third buffer to CSI. And so on. The bad thing is
+	 * that the first buffer will be written twice and the first frame
+	 * is dropped even the queued buffer is sufficient.
+	 * So, I make some improvement here. Pass the next buffer to CSI
+	 * just follow starting the CSI. In this case, the first frame
+	 * will be stored in first buffer, second frame in second buffer.
+	 * This method is used to avoid dropping the first frame, it
+	 * would also drop frame when lacking of queued buffer.
+	 */
+	next_buf = list_next_entry(buf, list);
+	next_buf->queued_to_csi = true;
+	sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
+
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+
+	ret = v4l2_subdev_call(subdev, video, s_stream, 1);
+	if (ret && ret != -ENOIOCTLCMD)
+		goto stop_csi_stream;
+
+	return 0;
+
+stop_csi_stream:
+	sun6i_csi_set_stream(video->csi, false);
+stop_media_pipeline:
+	media_pipeline_stop(&video->vdev.entity);
+clear_dma_queue:
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+	list_for_each_entry(buf, &video->dma_queue, list)
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
+	INIT_LIST_HEAD(&video->dma_queue);
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+
+	return ret;
+}
+
+static void sun6i_video_stop_streaming(struct vb2_queue *vq)
+{
+	struct sun6i_video *video = vb2_get_drv_priv(vq);
+	struct v4l2_subdev *subdev;
+	unsigned long flags;
+	struct sun6i_csi_buffer *buf;
+
+	subdev = sun6i_video_remote_subdev(video, NULL);
+	if (subdev)
+		v4l2_subdev_call(subdev, video, s_stream, 0);
+
+	sun6i_csi_set_stream(video->csi, false);
+
+	media_pipeline_stop(&video->vdev.entity);
+
+	/* Release all active buffers */
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+	list_for_each_entry(buf, &video->dma_queue, list)
+		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+	INIT_LIST_HEAD(&video->dma_queue);
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+}
+
+static void sun6i_video_buffer_queue(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct sun6i_csi_buffer *buf =
+			container_of(vbuf, struct sun6i_csi_buffer, vb);
+	struct sun6i_video *video = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long flags;
+
+	spin_lock_irqsave(&video->dma_queue_lock, flags);
+	buf->queued_to_csi = false;
+	list_add_tail(&buf->list, &video->dma_queue);
+	spin_unlock_irqrestore(&video->dma_queue_lock, flags);
+}
+
+void sun6i_video_frame_done(struct sun6i_video *video)
+{
+	struct sun6i_csi_buffer *buf;
+	struct sun6i_csi_buffer *next_buf;
+	struct vb2_v4l2_buffer *vbuf;
+
+	spin_lock(&video->dma_queue_lock);
+
+	buf = list_first_entry(&video->dma_queue,
+			       struct sun6i_csi_buffer, list);
+	if (list_is_last(&buf->list, &video->dma_queue)) {
+		dev_dbg(video->csi->dev, "Frame droped!\n");
+		goto unlock;
+	}
+
+	next_buf = list_next_entry(buf, list);
+	/* If a new buffer (#next_buf) had not been queued to CSI, the old
+	 * buffer (#buf) is still holding by CSI for storing the next
+	 * frame. So, we queue a new buffer (#next_buf) to CSI then wait
+	 * for next ISR call.
+	 */
+	if (!next_buf->queued_to_csi) {
+		next_buf->queued_to_csi = true;
+		sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
+		dev_dbg(video->csi->dev, "Frame droped!\n");
+		goto unlock;
+	}
+
+	list_del(&buf->list);
+	vbuf = &buf->vb;
+	vbuf->vb2_buf.timestamp = ktime_get_ns();
+	vbuf->sequence = video->sequence;
+	vb2_buffer_done(&vbuf->vb2_buf, VB2_BUF_STATE_DONE);
+
+	/* Prepare buffer for next frame but one.  */
+	if (!list_is_last(&next_buf->list, &video->dma_queue)) {
+		next_buf = list_next_entry(next_buf, list);
+		next_buf->queued_to_csi = true;
+		sun6i_csi_update_buf_addr(video->csi, next_buf->dma_addr);
+	} else {
+		dev_dbg(video->csi->dev, "Next frame will be dropped!\n");
+	}
+
+unlock:
+	video->sequence++;
+	spin_unlock(&video->dma_queue_lock);
+}
+
+static const struct vb2_ops sun6i_csi_vb2_ops = {
+	.queue_setup		= sun6i_video_queue_setup,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+	.buf_prepare		= sun6i_video_buffer_prepare,
+	.start_streaming	= sun6i_video_start_streaming,
+	.stop_streaming		= sun6i_video_stop_streaming,
+	.buf_queue		= sun6i_video_buffer_queue,
+};
+
+static int vidioc_querycap(struct file *file, void *priv,
+				struct v4l2_capability *cap)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	strscpy(cap->driver, "sun6i-video", sizeof(cap->driver));
+	strscpy(cap->card, video->vdev.name, sizeof(cap->card));
+	snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s",
+		 video->csi->dev->of_node->name);
+
+	return 0;
+}
+
+static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
+				   struct v4l2_fmtdesc *f)
+{
+	u32 index = f->index;
+
+	if (index >= ARRAY_SIZE(supported_pixformats))
+		return -EINVAL;
+
+	f->pixelformat = supported_pixformats[index];
+
+	return 0;
+}
+
+static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *fmt)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	*fmt = video->fmt;
+
+	return 0;
+}
+
+static int sun6i_video_try_fmt(struct sun6i_video *video,
+			       struct v4l2_format *f)
+{
+	struct v4l2_pix_format *pixfmt = &f->fmt.pix;
+	int bpp;
+
+	if (!is_pixformat_valid(pixfmt->pixelformat))
+		pixfmt->pixelformat = supported_pixformats[0];
+
+	v4l_bound_align_image(&pixfmt->width, MIN_WIDTH, MAX_WIDTH, 1,
+			      &pixfmt->height, MIN_HEIGHT, MAX_WIDTH, 1, 1);
+
+	bpp = sun6i_csi_get_bpp(pixfmt->pixelformat);
+	pixfmt->bytesperline = (pixfmt->width * bpp) >> 3;
+	pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
+
+	if (pixfmt->field == V4L2_FIELD_ANY)
+		pixfmt->field = V4L2_FIELD_NONE;
+
+	pixfmt->colorspace = V4L2_COLORSPACE_RAW;
+	pixfmt->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+	pixfmt->quantization = V4L2_QUANTIZATION_DEFAULT;
+	pixfmt->xfer_func = V4L2_XFER_FUNC_DEFAULT;
+
+	return 0;
+}
+
+static int sun6i_video_set_fmt(struct sun6i_video *video, struct v4l2_format *f)
+{
+	int ret;
+
+	ret = sun6i_video_try_fmt(video, f);
+	if (ret)
+		return ret;
+
+	video->fmt = *f;
+
+	return 0;
+}
+
+static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
+				struct v4l2_format *f)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	if (vb2_is_busy(&video->vb2_vidq))
+		return -EBUSY;
+
+	return sun6i_video_set_fmt(video, f);
+}
+
+static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
+				  struct v4l2_format *f)
+{
+	struct sun6i_video *video = video_drvdata(file);
+
+	return sun6i_video_try_fmt(video, f);
+}
+
+static int vidioc_enum_input(struct file *file, void *fh,
+			 struct v4l2_input *inp)
+{
+	if (inp->index != 0)
+		return -EINVAL;
+
+	strlcpy(inp->name, "camera", sizeof(inp->name));
+	inp->type = V4L2_INPUT_TYPE_CAMERA;
+
+	return 0;
+}
+
+static int vidioc_g_input(struct file *file, void *fh, unsigned int *i)
+{
+	*i = 0;
+
+	return 0;
+}
+
+static int vidioc_s_input(struct file *file, void *fh, unsigned int i)
+{
+	if (i != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops sun6i_video_ioctl_ops = {
+	.vidioc_querycap		= vidioc_querycap,
+	.vidioc_enum_fmt_vid_cap	= vidioc_enum_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap		= vidioc_g_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap		= vidioc_s_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap		= vidioc_try_fmt_vid_cap,
+
+	.vidioc_enum_input		= vidioc_enum_input,
+	.vidioc_s_input			= vidioc_s_input,
+	.vidioc_g_input			= vidioc_g_input,
+
+	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
+	.vidioc_querybuf		= vb2_ioctl_querybuf,
+	.vidioc_qbuf			= vb2_ioctl_qbuf,
+	.vidioc_expbuf			= vb2_ioctl_expbuf,
+	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
+	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
+	.vidioc_streamon		= vb2_ioctl_streamon,
+	.vidioc_streamoff		= vb2_ioctl_streamoff,
+
+	.vidioc_log_status		= v4l2_ctrl_log_status,
+	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
+};
+
+/* -----------------------------------------------------------------------------
+ * V4L2 file operations
+ */
+static int sun6i_video_open(struct file *file)
+{
+	struct sun6i_video *video = video_drvdata(file);
+	int ret;
+
+	if (mutex_lock_interruptible(&video->lock))
+		return -ERESTARTSYS;
+
+	ret = v4l2_fh_open(file);
+	if (ret < 0)
+		goto unlock;
+
+	ret = v4l2_pipeline_pm_use(&video->vdev.entity, 1);
+	if (ret < 0)
+		goto fh_release;
+
+	/* check if already powered */
+	if (!v4l2_fh_is_singular_file(file))
+		goto unlock;
+
+	ret = sun6i_csi_set_power(video->csi, true);
+	if (ret < 0)
+		goto fh_release;
+
+	mutex_unlock(&video->lock);
+	return 0;
+
+fh_release:
+	v4l2_fh_release(file);
+unlock:
+	mutex_unlock(&video->lock);
+	return ret;
+}
+
+static int sun6i_video_close(struct file *file)
+{
+	struct sun6i_video *video = video_drvdata(file);
+	bool last_fh;
+
+	mutex_lock(&video->lock);
+
+	last_fh = v4l2_fh_is_singular_file(file);
+
+	_vb2_fop_release(file, NULL);
+
+	v4l2_pipeline_pm_use(&video->vdev.entity, 0);
+
+	if (last_fh)
+		sun6i_csi_set_power(video->csi, false);
+
+	mutex_unlock(&video->lock);
+
+	return 0;
+}
+
+static const struct v4l2_file_operations sun6i_video_fops = {
+	.owner		= THIS_MODULE,
+	.open		= sun6i_video_open,
+	.release	= sun6i_video_close,
+	.unlocked_ioctl	= video_ioctl2,
+	.mmap		= vb2_fop_mmap,
+	.poll		= vb2_fop_poll
+};
+
+/* -----------------------------------------------------------------------------
+ * Media Operations
+ */
+static int sun6i_video_link_validate_get_format(struct media_pad *pad,
+						struct v4l2_subdev_format *fmt)
+{
+	if (is_media_entity_v4l2_subdev(pad->entity)) {
+		struct v4l2_subdev *sd =
+				media_entity_to_v4l2_subdev(pad->entity);
+
+		fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE;
+		fmt->pad = pad->index;
+		return v4l2_subdev_call(sd, pad, get_fmt, NULL, fmt);
+	}
+
+	return -EINVAL;
+}
+
+static int sun6i_video_link_validate(struct media_link *link)
+{
+	struct video_device *vdev = container_of(link->sink->entity,
+						 struct video_device, entity);
+	struct sun6i_video *video = video_get_drvdata(vdev);
+	struct v4l2_subdev_format source_fmt;
+	int ret;
+
+	video->mbus_code = 0;
+
+	if (!media_entity_remote_pad(link->sink->entity->pads)) {
+		dev_info(video->csi->dev,
+			 "video node %s pad not connected\n", vdev->name);
+		return -ENOLINK;
+	}
+
+	ret = sun6i_video_link_validate_get_format(link->source, &source_fmt);
+	if (ret < 0)
+		return ret;
+
+	if (!sun6i_csi_is_format_supported(video->csi,
+					   video->fmt.fmt.pix.pixelformat,
+					   source_fmt.format.code)) {
+		dev_err(video->csi->dev,
+			"Unsupported pixformat: 0x%x with mbus code: 0x%x!\n",
+			video->fmt.fmt.pix.pixelformat,
+			source_fmt.format.code);
+		return -EPIPE;
+	}
+
+	if (source_fmt.format.width != video->fmt.fmt.pix.width ||
+	    source_fmt.format.height != video->fmt.fmt.pix.height) {
+		dev_err(video->csi->dev,
+			"Wrong width or height %ux%u (%ux%u expected)\n",
+			video->fmt.fmt.pix.width, video->fmt.fmt.pix.height,
+			source_fmt.format.width, source_fmt.format.height);
+		return -EPIPE;
+	}
+
+	video->mbus_code = source_fmt.format.code;
+
+	return 0;
+}
+
+static const struct media_entity_operations sun6i_video_media_ops = {
+	.link_validate = sun6i_video_link_validate
+};
+
+int sun6i_video_init(struct sun6i_video *video, struct sun6i_csi *csi,
+		     const char *name)
+{
+	struct video_device *vdev = &video->vdev;
+	struct vb2_queue *vidq = &video->vb2_vidq;
+	struct v4l2_format fmt = { 0 };
+	int ret;
+
+	video->csi = csi;
+
+	/* Initialize the media entity... */
+	video->pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
+	vdev->entity.ops = &sun6i_video_media_ops;
+	ret = media_entity_pads_init(&vdev->entity, 1, &video->pad);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&video->lock);
+
+	INIT_LIST_HEAD(&video->dma_queue);
+	spin_lock_init(&video->dma_queue_lock);
+
+	video->sequence = 0;
+
+	/* Setup default format */
+	fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	fmt.fmt.pix.pixelformat = supported_pixformats[0];
+	fmt.fmt.pix.width = 1280;
+	fmt.fmt.pix.height = 720;
+	fmt.fmt.pix.field = V4L2_FIELD_NONE;
+	sun6i_video_set_fmt(video, &fmt);
+
+	/* Initialize videobuf2 queue */
+	vidq->type			= V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	vidq->io_modes			= VB2_MMAP | VB2_DMABUF;
+	vidq->drv_priv			= video;
+	vidq->buf_struct_size		= sizeof(struct sun6i_csi_buffer);
+	vidq->ops			= &sun6i_csi_vb2_ops;
+	vidq->mem_ops			= &vb2_dma_contig_memops;
+	vidq->timestamp_flags		= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	vidq->lock			= &video->lock;
+	/* Make sure non-dropped frame */
+	vidq->min_buffers_needed	= 3;
+	vidq->dev			= csi->dev;
+
+	ret = vb2_queue_init(vidq);
+	if (ret) {
+		v4l2_err(&csi->v4l2_dev, "vb2_queue_init failed: %d\n", ret);
+		goto clean_entity;
+	}
+
+	/* Register video device */
+	strlcpy(vdev->name, name, sizeof(vdev->name));
+	vdev->release		= video_device_release_empty;
+	vdev->fops		= &sun6i_video_fops;
+	vdev->ioctl_ops		= &sun6i_video_ioctl_ops;
+	vdev->vfl_type		= VFL_TYPE_GRABBER;
+	vdev->vfl_dir		= VFL_DIR_RX;
+	vdev->v4l2_dev		= &csi->v4l2_dev;
+	vdev->queue		= vidq;
+	vdev->lock		= &video->lock;
+	vdev->device_caps	= V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_CAPTURE;
+	video_set_drvdata(vdev, video);
+
+	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
+	if (ret < 0) {
+		v4l2_err(&csi->v4l2_dev,
+			 "video_register_device failed: %d\n", ret);
+		goto release_vb2;
+	}
+
+	return 0;
+
+release_vb2:
+	vb2_queue_release(&video->vb2_vidq);
+clean_entity:
+	media_entity_cleanup(&video->vdev.entity);
+	mutex_destroy(&video->lock);
+	return ret;
+}
+
+void sun6i_video_cleanup(struct sun6i_video *video)
+{
+	video_unregister_device(&video->vdev);
+	media_entity_cleanup(&video->vdev.entity);
+	vb2_queue_release(&video->vb2_vidq);
+	mutex_destroy(&video->lock);
+}

drivers/media/platform/sunxi/sun6i-csi/sun6i_video.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
+ * All rights reserved.
+ * Author: Yong Deng <yong.deng@magewell.com>
+ */
+
+#ifndef __SUN6I_VIDEO_H__
+#define __SUN6I_VIDEO_H__
+
+#include <media/v4l2-dev.h>
+#include <media/videobuf2-core.h>
+
+struct sun6i_csi;
+
+struct sun6i_video {
+	struct video_device		vdev;
+	struct media_pad		pad;
+	struct sun6i_csi		*csi;
+
+	struct mutex			lock;
+
+	struct vb2_queue		vb2_vidq;
+	spinlock_t			dma_queue_lock;
+	struct list_head		dma_queue;
+
+	unsigned int			sequence;
+	struct v4l2_format		fmt;
+	u32				mbus_code;
+};
+
+int sun6i_video_init(struct sun6i_video *video, struct sun6i_csi *csi,
+		     const char *name);
+void sun6i_video_cleanup(struct sun6i_video *video);
+
+void sun6i_video_frame_done(struct sun6i_video *video);
+
+#endif /* __SUN6I_VIDEO_H__ */