media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver

A V4L2 driver for Renesas R-Car MIPI CSI-2 receiver. The driver
supports the R-Car Gen3 SoCs where separate CSI-2 hardware blocks are
connected between the video sources and the video grabbers (VIN).

Driver is based on a prototype by Koji Matsuoka in the Renesas BSP.

Signed-off-by: Niklas Söderlund <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Maxime Ripard <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/rcar-vin/Kconfig

···
+config VIDEO_RCAR_CSI2
+	tristate "R-Car MIPI CSI-2 Receiver"
+	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && OF
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select V4L2_FWNODE
+	help
+	  Support for Renesas R-Car MIPI CSI-2 receiver.
+	  Supports R-Car Gen3 SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rcar-csi2.
+
 config VIDEO_RCAR_VIN
 	tristate "R-Car Video Input (VIN) Driver"
 	depends on VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API && OF && HAS_DMA && MEDIA_CONTROLLER

drivers/media/platform/rcar-vin/Makefile

···
 rcar-vin-objs = rcar-core.o rcar-dma.o rcar-v4l2.o
 
+obj-$(CONFIG_VIDEO_RCAR_CSI2) += rcar-csi2.o
 obj-$(CONFIG_VIDEO_RCAR_VIN) += rcar-vin.o

drivers/media/platform/rcar-vin/rcar-csi2.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Renesas R-Car MIPI CSI-2 Receiver
+ *
+ * Copyright (C) 2018 Renesas Electronics Corp.
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/sys_soc.h>
+
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
+#include <media/v4l2-subdev.h>
+
+struct rcar_csi2;
+
+/* Register offsets and bits */
+
+/* Control Timing Select */
+#define TREF_REG			0x00
+#define TREF_TREF			BIT(0)
+
+/* Software Reset */
+#define SRST_REG			0x04
+#define SRST_SRST			BIT(0)
+
+/* PHY Operation Control */
+#define PHYCNT_REG			0x08
+#define PHYCNT_SHUTDOWNZ		BIT(17)
+#define PHYCNT_RSTZ			BIT(16)
+#define PHYCNT_ENABLECLK		BIT(4)
+#define PHYCNT_ENABLE_3			BIT(3)
+#define PHYCNT_ENABLE_2			BIT(2)
+#define PHYCNT_ENABLE_1			BIT(1)
+#define PHYCNT_ENABLE_0			BIT(0)
+
+/* Checksum Control */
+#define CHKSUM_REG			0x0c
+#define CHKSUM_ECC_EN			BIT(1)
+#define CHKSUM_CRC_EN			BIT(0)
+
+/*
+ * Channel Data Type Select
+ * VCDT[0-15]:  Channel 1 VCDT[16-31]:  Channel 2
+ * VCDT2[0-15]: Channel 3 VCDT2[16-31]: Channel 4
+ */
+#define VCDT_REG			0x10
+#define VCDT2_REG			0x14
+#define VCDT_VCDTN_EN			BIT(15)
+#define VCDT_SEL_VC(n)			(((n) & 0x3) << 8)
+#define VCDT_SEL_DTN_ON			BIT(6)
+#define VCDT_SEL_DT(n)			(((n) & 0x3f) << 0)
+
+/* Frame Data Type Select */
+#define FRDT_REG			0x18
+
+/* Field Detection Control */
+#define FLD_REG				0x1c
+#define FLD_FLD_NUM(n)			(((n) & 0xff) << 16)
+#define FLD_FLD_EN4			BIT(3)
+#define FLD_FLD_EN3			BIT(2)
+#define FLD_FLD_EN2			BIT(1)
+#define FLD_FLD_EN			BIT(0)
+
+/* Automatic Standby Control */
+#define ASTBY_REG			0x20
+
+/* Long Data Type Setting 0 */
+#define LNGDT0_REG			0x28
+
+/* Long Data Type Setting 1 */
+#define LNGDT1_REG			0x2c
+
+/* Interrupt Enable */
+#define INTEN_REG			0x30
+
+/* Interrupt Source Mask */
+#define INTCLOSE_REG			0x34
+
+/* Interrupt Status Monitor */
+#define INTSTATE_REG			0x38
+#define INTSTATE_INT_ULPS_START		BIT(7)
+#define INTSTATE_INT_ULPS_END		BIT(6)
+
+/* Interrupt Error Status Monitor */
+#define INTERRSTATE_REG			0x3c
+
+/* Short Packet Data */
+#define SHPDAT_REG			0x40
+
+/* Short Packet Count */
+#define SHPCNT_REG			0x44
+
+/* LINK Operation Control */
+#define LINKCNT_REG			0x48
+#define LINKCNT_MONITOR_EN		BIT(31)
+#define LINKCNT_REG_MONI_PACT_EN	BIT(25)
+#define LINKCNT_ICLK_NONSTOP		BIT(24)
+
+/* Lane Swap */
+#define LSWAP_REG			0x4c
+#define LSWAP_L3SEL(n)			(((n) & 0x3) << 6)
+#define LSWAP_L2SEL(n)			(((n) & 0x3) << 4)
+#define LSWAP_L1SEL(n)			(((n) & 0x3) << 2)
+#define LSWAP_L0SEL(n)			(((n) & 0x3) << 0)
+
+/* PHY Test Interface Write Register */
+#define PHTW_REG			0x50
+#define PHTW_DWEN			BIT(24)
+#define PHTW_TESTDIN_DATA(n)		(((n & 0xff)) << 16)
+#define PHTW_CWEN			BIT(8)
+#define PHTW_TESTDIN_CODE(n)		((n & 0xff))
+
+struct phtw_value {
+	u16 data;
+	u16 code;
+};
+
+struct rcsi2_mbps_reg {
+	u16 mbps;
+	u16 reg;
+};
+
+static const struct rcsi2_mbps_reg phtw_mbps_h3_v3h_m3n[] = {
+	{ .mbps =   80, .reg = 0x86 },
+	{ .mbps =   90, .reg = 0x86 },
+	{ .mbps =  100, .reg = 0x87 },
+	{ .mbps =  110, .reg = 0x87 },
+	{ .mbps =  120, .reg = 0x88 },
+	{ .mbps =  130, .reg = 0x88 },
+	{ .mbps =  140, .reg = 0x89 },
+	{ .mbps =  150, .reg = 0x89 },
+	{ .mbps =  160, .reg = 0x8a },
+	{ .mbps =  170, .reg = 0x8a },
+	{ .mbps =  180, .reg = 0x8b },
+	{ .mbps =  190, .reg = 0x8b },
+	{ .mbps =  205, .reg = 0x8c },
+	{ .mbps =  220, .reg = 0x8d },
+	{ .mbps =  235, .reg = 0x8e },
+	{ .mbps =  250, .reg = 0x8e },
+	{ /* sentinel */ },
+};
+
+static const struct rcsi2_mbps_reg phtw_mbps_v3m_e3[] = {
+	{ .mbps =   80, .reg = 0x00 },
+	{ .mbps =   90, .reg = 0x20 },
+	{ .mbps =  100, .reg = 0x40 },
+	{ .mbps =  110, .reg = 0x02 },
+	{ .mbps =  130, .reg = 0x22 },
+	{ .mbps =  140, .reg = 0x42 },
+	{ .mbps =  150, .reg = 0x04 },
+	{ .mbps =  170, .reg = 0x24 },
+	{ .mbps =  180, .reg = 0x44 },
+	{ .mbps =  200, .reg = 0x06 },
+	{ .mbps =  220, .reg = 0x26 },
+	{ .mbps =  240, .reg = 0x46 },
+	{ .mbps =  250, .reg = 0x08 },
+	{ .mbps =  270, .reg = 0x28 },
+	{ .mbps =  300, .reg = 0x0a },
+	{ .mbps =  330, .reg = 0x2a },
+	{ .mbps =  360, .reg = 0x4a },
+	{ .mbps =  400, .reg = 0x0c },
+	{ .mbps =  450, .reg = 0x2c },
+	{ .mbps =  500, .reg = 0x0e },
+	{ .mbps =  550, .reg = 0x2e },
+	{ .mbps =  600, .reg = 0x10 },
+	{ .mbps =  650, .reg = 0x30 },
+	{ .mbps =  700, .reg = 0x12 },
+	{ .mbps =  750, .reg = 0x32 },
+	{ .mbps =  800, .reg = 0x52 },
+	{ .mbps =  850, .reg = 0x72 },
+	{ .mbps =  900, .reg = 0x14 },
+	{ .mbps =  950, .reg = 0x34 },
+	{ .mbps = 1000, .reg = 0x54 },
+	{ .mbps = 1050, .reg = 0x74 },
+	{ .mbps = 1125, .reg = 0x16 },
+	{ /* sentinel */ },
+};
+
+/* PHY Test Interface Clear */
+#define PHTC_REG			0x58
+#define PHTC_TESTCLR			BIT(0)
+
+/* PHY Frequency Control */
+#define PHYPLL_REG			0x68
+#define PHYPLL_HSFREQRANGE(n)		((n) << 16)
+
+static const struct rcsi2_mbps_reg hsfreqrange_h3_v3h_m3n[] = {
+	{ .mbps =   80, .reg = 0x00 },
+	{ .mbps =   90, .reg = 0x10 },
+	{ .mbps =  100, .reg = 0x20 },
+	{ .mbps =  110, .reg = 0x30 },
+	{ .mbps =  120, .reg = 0x01 },
+	{ .mbps =  130, .reg = 0x11 },
+	{ .mbps =  140, .reg = 0x21 },
+	{ .mbps =  150, .reg = 0x31 },
+	{ .mbps =  160, .reg = 0x02 },
+	{ .mbps =  170, .reg = 0x12 },
+	{ .mbps =  180, .reg = 0x22 },
+	{ .mbps =  190, .reg = 0x32 },
+	{ .mbps =  205, .reg = 0x03 },
+	{ .mbps =  220, .reg = 0x13 },
+	{ .mbps =  235, .reg = 0x23 },
+	{ .mbps =  250, .reg = 0x33 },
+	{ .mbps =  275, .reg = 0x04 },
+	{ .mbps =  300, .reg = 0x14 },
+	{ .mbps =  325, .reg = 0x25 },
+	{ .mbps =  350, .reg = 0x35 },
+	{ .mbps =  400, .reg = 0x05 },
+	{ .mbps =  450, .reg = 0x16 },
+	{ .mbps =  500, .reg = 0x26 },
+	{ .mbps =  550, .reg = 0x37 },
+	{ .mbps =  600, .reg = 0x07 },
+	{ .mbps =  650, .reg = 0x18 },
+	{ .mbps =  700, .reg = 0x28 },
+	{ .mbps =  750, .reg = 0x39 },
+	{ .mbps =  800, .reg = 0x09 },
+	{ .mbps =  850, .reg = 0x19 },
+	{ .mbps =  900, .reg = 0x29 },
+	{ .mbps =  950, .reg = 0x3a },
+	{ .mbps = 1000, .reg = 0x0a },
+	{ .mbps = 1050, .reg = 0x1a },
+	{ .mbps = 1100, .reg = 0x2a },
+	{ .mbps = 1150, .reg = 0x3b },
+	{ .mbps = 1200, .reg = 0x0b },
+	{ .mbps = 1250, .reg = 0x1b },
+	{ .mbps = 1300, .reg = 0x2b },
+	{ .mbps = 1350, .reg = 0x3c },
+	{ .mbps = 1400, .reg = 0x0c },
+	{ .mbps = 1450, .reg = 0x1c },
+	{ .mbps = 1500, .reg = 0x2c },
+	{ /* sentinel */ },
+};
+
+static const struct rcsi2_mbps_reg hsfreqrange_m3w_h3es1[] = {
+	{ .mbps =   80,	.reg = 0x00 },
+	{ .mbps =   90,	.reg = 0x10 },
+	{ .mbps =  100,	.reg = 0x20 },
+	{ .mbps =  110,	.reg = 0x30 },
+	{ .mbps =  120,	.reg = 0x01 },
+	{ .mbps =  130,	.reg = 0x11 },
+	{ .mbps =  140,	.reg = 0x21 },
+	{ .mbps =  150,	.reg = 0x31 },
+	{ .mbps =  160,	.reg = 0x02 },
+	{ .mbps =  170,	.reg = 0x12 },
+	{ .mbps =  180,	.reg = 0x22 },
+	{ .mbps =  190,	.reg = 0x32 },
+	{ .mbps =  205,	.reg = 0x03 },
+	{ .mbps =  220,	.reg = 0x13 },
+	{ .mbps =  235,	.reg = 0x23 },
+	{ .mbps =  250,	.reg = 0x33 },
+	{ .mbps =  275,	.reg = 0x04 },
+	{ .mbps =  300,	.reg = 0x14 },
+	{ .mbps =  325,	.reg = 0x05 },
+	{ .mbps =  350,	.reg = 0x15 },
+	{ .mbps =  400,	.reg = 0x25 },
+	{ .mbps =  450,	.reg = 0x06 },
+	{ .mbps =  500,	.reg = 0x16 },
+	{ .mbps =  550,	.reg = 0x07 },
+	{ .mbps =  600,	.reg = 0x17 },
+	{ .mbps =  650,	.reg = 0x08 },
+	{ .mbps =  700,	.reg = 0x18 },
+	{ .mbps =  750,	.reg = 0x09 },
+	{ .mbps =  800,	.reg = 0x19 },
+	{ .mbps =  850,	.reg = 0x29 },
+	{ .mbps =  900,	.reg = 0x39 },
+	{ .mbps =  950,	.reg = 0x0a },
+	{ .mbps = 1000,	.reg = 0x1a },
+	{ .mbps = 1050,	.reg = 0x2a },
+	{ .mbps = 1100,	.reg = 0x3a },
+	{ .mbps = 1150,	.reg = 0x0b },
+	{ .mbps = 1200,	.reg = 0x1b },
+	{ .mbps = 1250,	.reg = 0x2b },
+	{ .mbps = 1300,	.reg = 0x3b },
+	{ .mbps = 1350,	.reg = 0x0c },
+	{ .mbps = 1400,	.reg = 0x1c },
+	{ .mbps = 1450,	.reg = 0x2c },
+	{ .mbps = 1500,	.reg = 0x3c },
+	{ /* sentinel */ },
+};
+
+/* PHY ESC Error Monitor */
+#define PHEERM_REG			0x74
+
+/* PHY Clock Lane Monitor */
+#define PHCLM_REG			0x78
+#define PHCLM_STOPSTATECKL		BIT(0)
+
+/* PHY Data Lane Monitor */
+#define PHDLM_REG			0x7c
+
+/* CSI0CLK Frequency Configuration Preset Register */
+#define CSI0CLKFCPR_REG			0x260
+#define CSI0CLKFREQRANGE(n)		((n & 0x3f) << 16)
+
+struct rcar_csi2_format {
+	u32 code;
+	unsigned int datatype;
+	unsigned int bpp;
+};
+
+static const struct rcar_csi2_format rcar_csi2_formats[] = {
+	{ .code = MEDIA_BUS_FMT_RGB888_1X24,	.datatype = 0x24, .bpp = 24 },
+	{ .code = MEDIA_BUS_FMT_UYVY8_1X16,	.datatype = 0x1e, .bpp = 16 },
+	{ .code = MEDIA_BUS_FMT_YUYV8_1X16,	.datatype = 0x1e, .bpp = 16 },
+	{ .code = MEDIA_BUS_FMT_UYVY8_2X8,	.datatype = 0x1e, .bpp = 16 },
+	{ .code = MEDIA_BUS_FMT_YUYV10_2X10,	.datatype = 0x1e, .bpp = 20 },
+};
+
+static const struct rcar_csi2_format *rcsi2_code_to_fmt(unsigned int code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(rcar_csi2_formats); i++)
+		if (rcar_csi2_formats[i].code == code)
+			return &rcar_csi2_formats[i];
+
+	return NULL;
+}
+
+enum rcar_csi2_pads {
+	RCAR_CSI2_SINK,
+	RCAR_CSI2_SOURCE_VC0,
+	RCAR_CSI2_SOURCE_VC1,
+	RCAR_CSI2_SOURCE_VC2,
+	RCAR_CSI2_SOURCE_VC3,
+	NR_OF_RCAR_CSI2_PAD,
+};
+
+struct rcar_csi2_info {
+	int (*init_phtw)(struct rcar_csi2 *priv, unsigned int mbps);
+	const struct rcsi2_mbps_reg *hsfreqrange;
+	unsigned int csi0clkfreqrange;
+	bool clear_ulps;
+};
+
+struct rcar_csi2 {
+	struct device *dev;
+	void __iomem *base;
+	const struct rcar_csi2_info *info;
+
+	struct v4l2_subdev subdev;
+	struct media_pad pads[NR_OF_RCAR_CSI2_PAD];
+
+	struct v4l2_async_notifier notifier;
+	struct v4l2_async_subdev asd;
+	struct v4l2_subdev *remote;
+
+	struct v4l2_mbus_framefmt mf;
+
+	struct mutex lock;
+	int stream_count;
+
+	unsigned short lanes;
+	unsigned char lane_swap[4];
+};
+
+static inline struct rcar_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct rcar_csi2, subdev);
+}
+
+static inline struct rcar_csi2 *notifier_to_csi2(struct v4l2_async_notifier *n)
+{
+	return container_of(n, struct rcar_csi2, notifier);
+}
+
+static u32 rcsi2_read(struct rcar_csi2 *priv, unsigned int reg)
+{
+	return ioread32(priv->base + reg);
+}
+
+static void rcsi2_write(struct rcar_csi2 *priv, unsigned int reg, u32 data)
+{
+	iowrite32(data, priv->base + reg);
+}
+
+static void rcsi2_reset(struct rcar_csi2 *priv)
+{
+	rcsi2_write(priv, SRST_REG, SRST_SRST);
+	usleep_range(100, 150);
+	rcsi2_write(priv, SRST_REG, 0);
+}
+
+static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
+{
+	unsigned int timeout;
+
+	/* Wait for the clock and data lanes to enter LP-11 state. */
+	for (timeout = 0; timeout <= 20; timeout++) {
+		const u32 lane_mask = (1 << priv->lanes) - 1;
+
+		if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL)  &&
+		    (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
+			return 0;
+
+		usleep_range(1000, 2000);
+	}
+
+	dev_err(priv->dev, "Timeout waiting for LP-11 state\n");
+
+	return -ETIMEDOUT;
+}
+
+static int rcsi2_set_phypll(struct rcar_csi2 *priv, unsigned int mbps)
+{
+	const struct rcsi2_mbps_reg *hsfreq;
+
+	for (hsfreq = priv->info->hsfreqrange; hsfreq->mbps != 0; hsfreq++)
+		if (hsfreq->mbps >= mbps)
+			break;
+
+	if (!hsfreq->mbps) {
+		dev_err(priv->dev, "Unsupported PHY speed (%u Mbps)", mbps);
+		return -ERANGE;
+	}
+
+	rcsi2_write(priv, PHYPLL_REG, PHYPLL_HSFREQRANGE(hsfreq->reg));
+
+	return 0;
+}
+
+static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
+{
+	struct v4l2_subdev *source;
+	struct v4l2_ctrl *ctrl;
+	u64 mbps;
+
+	if (!priv->remote)
+		return -ENODEV;
+
+	source = priv->remote;
+
+	/* Read the pixel rate control from remote. */
+	ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE);
+	if (!ctrl) {
+		dev_err(priv->dev, "no pixel rate control in subdev %s\n",
+			source->name);
+		return -EINVAL;
+	}
+
+	/*
+	 * Calculate the phypll in mbps.
+	 * link_freq = (pixel_rate * bits_per_sample) / (2 * nr_of_lanes)
+	 * bps = link_freq * 2
+	 */
+	mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * bpp;
+	do_div(mbps, priv->lanes * 1000000);
+
+	return mbps;
+}
+
+static int rcsi2_start(struct rcar_csi2 *priv)
+{
+	const struct rcar_csi2_format *format;
+	u32 phycnt, vcdt = 0, vcdt2 = 0;
+	unsigned int i;
+	int mbps, ret;
+
+	dev_dbg(priv->dev, "Input size (%ux%u%c)\n",
+		priv->mf.width, priv->mf.height,
+		priv->mf.field == V4L2_FIELD_NONE ? 'p' : 'i');
+
+	/* Code is validated in set_fmt. */
+	format = rcsi2_code_to_fmt(priv->mf.code);
+
+	/*
+	 * Enable all Virtual Channels.
+	 *
+	 * NOTE: It's not possible to get individual datatype for each
+	 *       source virtual channel. Once this is possible in V4L2
+	 *       it should be used here.
+	 */
+	for (i = 0; i < 4; i++) {
+		u32 vcdt_part;
+
+		vcdt_part = VCDT_SEL_VC(i) | VCDT_VCDTN_EN | VCDT_SEL_DTN_ON |
+			VCDT_SEL_DT(format->datatype);
+
+		/* Store in correct reg and offset. */
+		if (i < 2)
+			vcdt |= vcdt_part << ((i % 2) * 16);
+		else
+			vcdt2 |= vcdt_part << ((i % 2) * 16);
+	}
+
+	phycnt = PHYCNT_ENABLECLK;
+	phycnt |= (1 << priv->lanes) - 1;
+
+	mbps = rcsi2_calc_mbps(priv, format->bpp);
+	if (mbps < 0)
+		return mbps;
+
+	/* Init */
+	rcsi2_write(priv, TREF_REG, TREF_TREF);
+	rcsi2_reset(priv);
+	rcsi2_write(priv, PHTC_REG, 0);
+
+	/* Configure */
+	rcsi2_write(priv, FLD_REG, FLD_FLD_NUM(2) | FLD_FLD_EN4 |
+		    FLD_FLD_EN3 | FLD_FLD_EN2 | FLD_FLD_EN);
+	rcsi2_write(priv, VCDT_REG, vcdt);
+	rcsi2_write(priv, VCDT2_REG, vcdt2);
+	/* Lanes are zero indexed. */
+	rcsi2_write(priv, LSWAP_REG,
+		    LSWAP_L0SEL(priv->lane_swap[0] - 1) |
+		    LSWAP_L1SEL(priv->lane_swap[1] - 1) |
+		    LSWAP_L2SEL(priv->lane_swap[2] - 1) |
+		    LSWAP_L3SEL(priv->lane_swap[3] - 1));
+
+	/* Start */
+	if (priv->info->init_phtw) {
+		ret = priv->info->init_phtw(priv, mbps);
+		if (ret)
+			return ret;
+	}
+
+	if (priv->info->hsfreqrange) {
+		ret = rcsi2_set_phypll(priv, mbps);
+		if (ret)
+			return ret;
+	}
+
+	if (priv->info->csi0clkfreqrange)
+		rcsi2_write(priv, CSI0CLKFCPR_REG,
+			    CSI0CLKFREQRANGE(priv->info->csi0clkfreqrange));
+
+	rcsi2_write(priv, PHYCNT_REG, phycnt);
+	rcsi2_write(priv, LINKCNT_REG, LINKCNT_MONITOR_EN |
+		    LINKCNT_REG_MONI_PACT_EN | LINKCNT_ICLK_NONSTOP);
+	rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ);
+	rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ | PHYCNT_RSTZ);
+
+	ret = rcsi2_wait_phy_start(priv);
+	if (ret)
+		return ret;
+
+	/* Clear Ultra Low Power interrupt. */
+	if (priv->info->clear_ulps)
+		rcsi2_write(priv, INTSTATE_REG,
+			    INTSTATE_INT_ULPS_START |
+			    INTSTATE_INT_ULPS_END);
+	return 0;
+}
+
+static void rcsi2_stop(struct rcar_csi2 *priv)
+{
+	rcsi2_write(priv, PHYCNT_REG, 0);
+
+	rcsi2_reset(priv);
+
+	rcsi2_write(priv, PHTC_REG, PHTC_TESTCLR);
+}
+
+static int rcsi2_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct rcar_csi2 *priv = sd_to_csi2(sd);
+	struct v4l2_subdev *nextsd;
+	int ret = 0;
+
+	mutex_lock(&priv->lock);
+
+	if (!priv->remote) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	nextsd = priv->remote;
+
+	if (enable && priv->stream_count == 0) {
+		pm_runtime_get_sync(priv->dev);
+
+		ret = rcsi2_start(priv);
+		if (ret) {
+			pm_runtime_put(priv->dev);
+			goto out;
+		}
+
+		ret = v4l2_subdev_call(nextsd, video, s_stream, 1);
+		if (ret) {
+			rcsi2_stop(priv);
+			pm_runtime_put(priv->dev);
+			goto out;
+		}
+	} else if (!enable && priv->stream_count == 1) {
+		rcsi2_stop(priv);
+		v4l2_subdev_call(nextsd, video, s_stream, 0);
+		pm_runtime_put(priv->dev);
+	}
+
+	priv->stream_count += enable ? 1 : -1;
+out:
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int rcsi2_set_pad_format(struct v4l2_subdev *sd,
+				struct v4l2_subdev_pad_config *cfg,
+				struct v4l2_subdev_format *format)
+{
+	struct rcar_csi2 *priv = sd_to_csi2(sd);
+	struct v4l2_mbus_framefmt *framefmt;
+
+	if (!rcsi2_code_to_fmt(format->format.code))
+		return -EINVAL;
+
+	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
+		priv->mf = format->format;
+	} else {
+		framefmt = v4l2_subdev_get_try_format(sd, cfg, 0);
+		*framefmt = format->format;
+	}
+
+	return 0;
+}
+
+static int rcsi2_get_pad_format(struct v4l2_subdev *sd,
+				struct v4l2_subdev_pad_config *cfg,
+				struct v4l2_subdev_format *format)
+{
+	struct rcar_csi2 *priv = sd_to_csi2(sd);
+
+	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+		format->format = priv->mf;
+	else
+		format->format = *v4l2_subdev_get_try_format(sd, cfg, 0);
+
+	return 0;
+}
+
+static const struct v4l2_subdev_video_ops rcar_csi2_video_ops = {
+	.s_stream = rcsi2_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops rcar_csi2_pad_ops = {
+	.set_fmt = rcsi2_set_pad_format,
+	.get_fmt = rcsi2_get_pad_format,
+};
+
+static const struct v4l2_subdev_ops rcar_csi2_subdev_ops = {
+	.video	= &rcar_csi2_video_ops,
+	.pad	= &rcar_csi2_pad_ops,
+};
+
+/* -----------------------------------------------------------------------------
+ * Async handling and registration of subdevices and links.
+ */
+
+static int rcsi2_notify_bound(struct v4l2_async_notifier *notifier,
+			      struct v4l2_subdev *subdev,
+			      struct v4l2_async_subdev *asd)
+{
+	struct rcar_csi2 *priv = notifier_to_csi2(notifier);
+	int pad;
+
+	pad = media_entity_get_fwnode_pad(&subdev->entity, asd->match.fwnode,
+					  MEDIA_PAD_FL_SOURCE);
+	if (pad < 0) {
+		dev_err(priv->dev, "Failed to find pad for %s\n", subdev->name);
+		return pad;
+	}
+
+	priv->remote = subdev;
+
+	dev_dbg(priv->dev, "Bound %s pad: %d\n", subdev->name, pad);
+
+	return media_create_pad_link(&subdev->entity, pad,
+				     &priv->subdev.entity, 0,
+				     MEDIA_LNK_FL_ENABLED |
+				     MEDIA_LNK_FL_IMMUTABLE);
+}
+
+static void rcsi2_notify_unbind(struct v4l2_async_notifier *notifier,
+				struct v4l2_subdev *subdev,
+				struct v4l2_async_subdev *asd)
+{
+	struct rcar_csi2 *priv = notifier_to_csi2(notifier);
+
+	priv->remote = NULL;
+
+	dev_dbg(priv->dev, "Unbind %s\n", subdev->name);
+}
+
+static const struct v4l2_async_notifier_operations rcar_csi2_notify_ops = {
+	.bound = rcsi2_notify_bound,
+	.unbind = rcsi2_notify_unbind,
+};
+
+static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
+			    struct v4l2_fwnode_endpoint *vep)
+{
+	unsigned int i;
+
+	/* Only port 0 endpoint 0 is valid. */
+	if (vep->base.port || vep->base.id)
+		return -ENOTCONN;
+
+	if (vep->bus_type != V4L2_MBUS_CSI2) {
+		dev_err(priv->dev, "Unsupported bus: %u\n", vep->bus_type);
+		return -EINVAL;
+	}
+
+	priv->lanes = vep->bus.mipi_csi2.num_data_lanes;
+	if (priv->lanes != 1 && priv->lanes != 2 && priv->lanes != 4) {
+		dev_err(priv->dev, "Unsupported number of data-lanes: %u\n",
+			priv->lanes);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(priv->lane_swap); i++) {
+		priv->lane_swap[i] = i < priv->lanes ?
+			vep->bus.mipi_csi2.data_lanes[i] : i;
+
+		/* Check for valid lane number. */
+		if (priv->lane_swap[i] < 1 || priv->lane_swap[i] > 4) {
+			dev_err(priv->dev, "data-lanes must be in 1-4 range\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int rcsi2_parse_dt(struct rcar_csi2 *priv)
+{
+	struct device_node *ep;
+	struct v4l2_fwnode_endpoint v4l2_ep;
+	int ret;
+
+	ep = of_graph_get_endpoint_by_regs(priv->dev->of_node, 0, 0);
+	if (!ep) {
+		dev_err(priv->dev, "Not connected to subdevice\n");
+		return -EINVAL;
+	}
+
+	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &v4l2_ep);
+	if (ret) {
+		dev_err(priv->dev, "Could not parse v4l2 endpoint\n");
+		of_node_put(ep);
+		return -EINVAL;
+	}
+
+	ret = rcsi2_parse_v4l2(priv, &v4l2_ep);
+	if (ret) {
+		of_node_put(ep);
+		return ret;
+	}
+
+	priv->asd.match.fwnode =
+		fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
+	priv->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+
+	of_node_put(ep);
+
+	priv->notifier.subdevs = devm_kzalloc(priv->dev,
+					      sizeof(*priv->notifier.subdevs),
+					      GFP_KERNEL);
+	if (!priv->notifier.subdevs)
+		return -ENOMEM;
+
+	priv->notifier.num_subdevs = 1;
+	priv->notifier.subdevs[0] = &priv->asd;
+	priv->notifier.ops = &rcar_csi2_notify_ops;
+
+	dev_dbg(priv->dev, "Found '%pOF'\n",
+		to_of_node(priv->asd.match.fwnode));
+
+	return v4l2_async_subdev_notifier_register(&priv->subdev,
+						   &priv->notifier);
+}
+
+/* -----------------------------------------------------------------------------
+ * PHTW initialization sequences.
+ *
+ * NOTE: Magic values are from the datasheet and lack documentation.
+ */
+
+static int rcsi2_phtw_write(struct rcar_csi2 *priv, u16 data, u16 code)
+{
+	unsigned int timeout;
+
+	rcsi2_write(priv, PHTW_REG,
+		    PHTW_DWEN | PHTW_TESTDIN_DATA(data) |
+		    PHTW_CWEN | PHTW_TESTDIN_CODE(code));
+
+	/* Wait for DWEN and CWEN to be cleared by hardware. */
+	for (timeout = 0; timeout <= 20; timeout++) {
+		if (!(rcsi2_read(priv, PHTW_REG) & (PHTW_DWEN | PHTW_CWEN)))
+			return 0;
+
+		usleep_range(1000, 2000);
+	}
+
+	dev_err(priv->dev, "Timeout waiting for PHTW_DWEN and/or PHTW_CWEN\n");
+
+	return -ETIMEDOUT;
+}
+
+static int rcsi2_phtw_write_array(struct rcar_csi2 *priv,
+				  const struct phtw_value *values)
+{
+	const struct phtw_value *value;
+	int ret;
+
+	for (value = values; value->data || value->code; value++) {
+		ret = rcsi2_phtw_write(priv, value->data, value->code);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int rcsi2_phtw_write_mbps(struct rcar_csi2 *priv, unsigned int mbps,
+				 const struct rcsi2_mbps_reg *values, u16 code)
+{
+	const struct rcsi2_mbps_reg *value;
+
+	for (value = values; value->mbps; value++)
+		if (value->mbps >= mbps)
+			break;
+
+	if (!value->mbps) {
+		dev_err(priv->dev, "Unsupported PHY speed (%u Mbps)", mbps);
+		return -ERANGE;
+	}
+
+	return rcsi2_phtw_write(priv, value->reg, code);
+}
+
+static int rcsi2_init_phtw_h3_v3h_m3n(struct rcar_csi2 *priv, unsigned int mbps)
+{
+	static const struct phtw_value step1[] = {
+		{ .data = 0xcc, .code = 0xe2 },
+		{ .data = 0x01, .code = 0xe3 },
+		{ .data = 0x11, .code = 0xe4 },
+		{ .data = 0x01, .code = 0xe5 },
+		{ .data = 0x10, .code = 0x04 },
+		{ /* sentinel */ },
+	};
+
+	static const struct phtw_value step2[] = {
+		{ .data = 0x38, .code = 0x08 },
+		{ .data = 0x01, .code = 0x00 },
+		{ .data = 0x4b, .code = 0xac },
+		{ .data = 0x03, .code = 0x00 },
+		{ .data = 0x80, .code = 0x07 },
+		{ /* sentinel */ },
+	};
+
+	int ret;
+
+	ret = rcsi2_phtw_write_array(priv, step1);
+	if (ret)
+		return ret;
+
+	if (mbps <= 250) {
+		ret = rcsi2_phtw_write(priv, 0x39, 0x05);
+		if (ret)
+			return ret;
+
+		ret = rcsi2_phtw_write_mbps(priv, mbps, phtw_mbps_h3_v3h_m3n,
+					    0xf1);
+		if (ret)
+			return ret;
+	}
+
+	return rcsi2_phtw_write_array(priv, step2);
+}
+
+static int rcsi2_init_phtw_v3m_e3(struct rcar_csi2 *priv, unsigned int mbps)
+{
+	static const struct phtw_value step1[] = {
+		{ .data = 0xed, .code = 0x34 },
+		{ .data = 0xed, .code = 0x44 },
+		{ .data = 0xed, .code = 0x54 },
+		{ .data = 0xed, .code = 0x84 },
+		{ .data = 0xed, .code = 0x94 },
+		{ /* sentinel */ },
+	};
+
+	int ret;
+
+	ret = rcsi2_phtw_write_mbps(priv, mbps, phtw_mbps_v3m_e3, 0x44);
+	if (ret)
+		return ret;
+
+	return rcsi2_phtw_write_array(priv, step1);
+}
+
+/* -----------------------------------------------------------------------------
+ * Platform Device Driver.
+ */
+
+static const struct media_entity_operations rcar_csi2_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int rcsi2_probe_resources(struct rcar_csi2 *priv,
+				 struct platform_device *pdev)
+{
+	struct resource *res;
+	int irq;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	return 0;
+}
+
+static const struct rcar_csi2_info rcar_csi2_info_r8a7795 = {
+	.init_phtw = rcsi2_init_phtw_h3_v3h_m3n,
+	.hsfreqrange = hsfreqrange_h3_v3h_m3n,
+	.csi0clkfreqrange = 0x20,
+	.clear_ulps = true,
+};
+
+static const struct rcar_csi2_info rcar_csi2_info_r8a7795es1 = {
+	.hsfreqrange = hsfreqrange_m3w_h3es1,
+};
+
+static const struct rcar_csi2_info rcar_csi2_info_r8a7796 = {
+	.hsfreqrange = hsfreqrange_m3w_h3es1,
+};
+
+static const struct rcar_csi2_info rcar_csi2_info_r8a77965 = {
+	.init_phtw = rcsi2_init_phtw_h3_v3h_m3n,
+	.hsfreqrange = hsfreqrange_h3_v3h_m3n,
+	.csi0clkfreqrange = 0x20,
+	.clear_ulps = true,
+};
+
+static const struct rcar_csi2_info rcar_csi2_info_r8a77970 = {
+	.init_phtw = rcsi2_init_phtw_v3m_e3,
+};
+
+static const struct of_device_id rcar_csi2_of_table[] = {
+	{
+		.compatible = "renesas,r8a7795-csi2",
+		.data = &rcar_csi2_info_r8a7795,
+	},
+	{
+		.compatible = "renesas,r8a7796-csi2",
+		.data = &rcar_csi2_info_r8a7796,
+	},
+	{
+		.compatible = "renesas,r8a77965-csi2",
+		.data = &rcar_csi2_info_r8a77965,
+	},
+	{
+		.compatible = "renesas,r8a77970-csi2",
+		.data = &rcar_csi2_info_r8a77970,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rcar_csi2_of_table);
+
+static const struct soc_device_attribute r8a7795es1[] = {
+	{
+		.soc_id = "r8a7795", .revision = "ES1.*",
+		.data = &rcar_csi2_info_r8a7795es1,
+	},
+	{ /* sentinel */ },
+};
+
+static int rcsi2_probe(struct platform_device *pdev)
+{
+	const struct soc_device_attribute *attr;
+	struct rcar_csi2 *priv;
+	unsigned int i;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->info = of_device_get_match_data(&pdev->dev);
+
+	/*
+	 * r8a7795 ES1.x behaves differently than the ES2.0+ but doesn't
+	 * have it's own compatible string.
+	 */
+	attr = soc_device_match(r8a7795es1);
+	if (attr)
+		priv->info = attr->data;
+
+	priv->dev = &pdev->dev;
+
+	mutex_init(&priv->lock);
+	priv->stream_count = 0;
+
+	ret = rcsi2_probe_resources(priv, pdev);
+	if (ret) {
+		dev_err(priv->dev, "Failed to get resources\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = rcsi2_parse_dt(priv);
+	if (ret)
+		return ret;
+
+	priv->subdev.owner = THIS_MODULE;
+	priv->subdev.dev = &pdev->dev;
+	v4l2_subdev_init(&priv->subdev, &rcar_csi2_subdev_ops);
+	v4l2_set_subdevdata(&priv->subdev, &pdev->dev);
+	snprintf(priv->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s %s",
+		 KBUILD_MODNAME, dev_name(&pdev->dev));
+	priv->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	priv->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
+	priv->subdev.entity.ops = &rcar_csi2_entity_ops;
+
+	priv->pads[RCAR_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
+	for (i = RCAR_CSI2_SOURCE_VC0; i < NR_OF_RCAR_CSI2_PAD; i++)
+		priv->pads[i].flags = MEDIA_PAD_FL_SOURCE;
+
+	ret = media_entity_pads_init(&priv->subdev.entity, NR_OF_RCAR_CSI2_PAD,
+				     priv->pads);
+	if (ret)
+		goto error;
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = v4l2_async_register_subdev(&priv->subdev);
+	if (ret < 0)
+		goto error;
+
+	dev_info(priv->dev, "%d lanes found\n", priv->lanes);
+
+	return 0;
+
+error:
+	v4l2_async_notifier_unregister(&priv->notifier);
+	v4l2_async_notifier_cleanup(&priv->notifier);
+
+	return ret;
+}
+
+static int rcsi2_remove(struct platform_device *pdev)
+{
+	struct rcar_csi2 *priv = platform_get_drvdata(pdev);
+
+	v4l2_async_notifier_unregister(&priv->notifier);
+	v4l2_async_notifier_cleanup(&priv->notifier);
+	v4l2_async_unregister_subdev(&priv->subdev);
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static struct platform_driver rcar_csi2_pdrv = {
+	.remove	= rcsi2_remove,
+	.probe	= rcsi2_probe,
+	.driver	= {
+		.name	= "rcar-csi2",
+		.of_match_table	= rcar_csi2_of_table,
+	},
+};
+
+module_platform_driver(rcar_csi2_pdrv);
+
+MODULE_AUTHOR("Niklas Söderlund <[e-mail]>");
+MODULE_DESCRIPTION("Renesas R-Car MIPI CSI-2 receiver driver");
+MODULE_LICENSE("GPL");