[PATCH v4 2/2] media:st-mipid02: MIPID02 CSI-2 to PARALLEL bridge driver

[Mickael Guene <mickael.guene@st.com>]

This V4L2 subdev driver enables STMicroelectronics MIPID02 device.

Signed-off-by: Mickael Guene <mickael.guene@st.com>
---

Changes in v4:
- Add support of enum_mbus_code
- Only use V4L2_CID_PIXEL_RATE to compute link speed
- Use MEDIA_BUS_FMT_UYVY8_1X16 instead of MEDIA_BUS_FMT_UYVY8_2X8 for CSI-2 link
- Fix miscellaneous typos
- Fix wrong code behavior for set_fmt and get_fmt

Changes in v3:
- Fix potential wrong error code for mipid02_stream_disable and mipid02_stream_enable
- Remove useless memset for ep in mipid02_parse_rx_ep and mipid02_parse_tx_ep
- Add second CSI-2 input pad even if it's not yet supported
- Add support of get_fmt, set_fmt and link_validate and only access subdev connected to mipid02

Changes in v2:
- Merge MAINTAINERS patch 3 into patch 1 and 2
- Fix line too long in Kconfig
- Add missing delay after reset release
- Various style fixes
- Fix mipid02_stream_enable returning no error when mipid02_find_sensor failed

 MAINTAINERS                    |    1 +
 drivers/media/i2c/Kconfig      |   14 +
 drivers/media/i2c/Makefile     |    1 +
 drivers/media/i2c/st-mipid02.c | 1043 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 1059 insertions(+)
 create mode 100644 drivers/media/i2c/st-mipid02.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 74da99d..a14fe81 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14673,6 +14673,7 @@ M:	Mickael Guene <mickael.guene@st.com>
 L:	linux-media@vger.kernel.org
 T:	git git://linuxtv.org/media_tree.git
 S:	Maintained
+F:	drivers/media/i2c/st-mipid02.c
 F:	Documentation/devicetree/bindings/media/i2c/st,st-mipid02.txt
 
 ST STM32 I2C/SMBUS DRIVER
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 1a1746b..2dc9e15 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1135,6 +1135,20 @@ config VIDEO_I2C
 	  To compile this driver as a module, choose M here: the
 	  module will be called video-i2c
 
+config VIDEO_ST_MIPID02
+	tristate "STMicroelectronics MIPID02 CSI-2 to PARALLEL bridge"
+	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+	depends on MEDIA_CAMERA_SUPPORT
+	depends on MEDIA_CONTROLLER
+	select V4L2_FWNODE
+	help
+	  Support for STMicroelectronics MIPID02 CSI-2 to PARALLEL bridge.
+	  It is used to allow usage of CSI-2 sensor with PARALLEL port
+	  controller.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called st-mipid02.
+
 endmenu
 
 endif
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index a64fca8..d8ad9da 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -113,5 +113,6 @@ obj-$(CONFIG_VIDEO_IMX258)	+= imx258.o
 obj-$(CONFIG_VIDEO_IMX274)	+= imx274.o
 obj-$(CONFIG_VIDEO_IMX319)	+= imx319.o
 obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
+obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
 
 obj-$(CONFIG_SDR_MAX2175) += max2175.o
diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
new file mode 100644
index 0000000..1d09bae
--- /dev/null
+++ b/drivers/media/i2c/st-mipid02.c
@@ -0,0 +1,1043 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for ST MIPID02 CSI-2 to PARALLEL bridge
+ *
+ * Copyright (C) STMicroelectronics SA 2019
+ * Authors: Mickael Guene <mickael.guene@st.com>
+ *          for STMicroelectronics.
+ *
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+#define MIPID02_CLK_LANE_WR_REG1			0x01
+#define MIPID02_CLK_LANE_REG1				0x02
+#define MIPID02_CLK_LANE_REG3				0x04
+#define MIPID02_DATA_LANE0_REG1				0x05
+#define MIPID02_DATA_LANE0_REG2				0x06
+#define MIPID02_DATA_LANE1_REG1				0x09
+#define MIPID02_DATA_LANE1_REG2				0x0a
+#define MIPID02_MODE_REG1				0x14
+#define MIPID02_MODE_REG2				0x15
+#define MIPID02_DATA_ID_RREG				0x17
+#define MIPID02_DATA_SELECTION_CTRL			0x19
+#define MIPID02_PIX_WIDTH_CTRL				0x1e
+#define MIPID02_PIX_WIDTH_CTRL_EMB			0x1f
+
+/* Bits definition for MIPID02_CLK_LANE_REG1 */
+#define CLK_ENABLE					BIT(0)
+/* Bits definition for MIPID02_CLK_LANE_REG3 */
+#define CLK_MIPI_CSI					BIT(1)
+/* Bits definition for MIPID02_DATA_LANE0_REG1 */
+#define DATA_ENABLE					BIT(0)
+/* Bits definition for MIPID02_DATA_LANEx_REG2 */
+#define DATA_MIPI_CSI					BIT(0)
+/* Bits definition for MIPID02_MODE_REG1 */
+#define MODE_DATA_SWAP					BIT(2)
+#define MODE_NO_BYPASS					BIT(6)
+/* Bits definition for MIPID02_MODE_REG2 */
+#define MODE_HSYNC_ACTIVE_HIGH				BIT(1)
+#define MODE_VSYNC_ACTIVE_HIGH				BIT(2)
+/* Bits definition for MIPID02_DATA_SELECTION_CTRL */
+#define SELECTION_MANUAL_DATA				BIT(2)
+#define SELECTION_MANUAL_WIDTH				BIT(3)
+
+static const u32 mipid02_supported_fmt_codes[] = {
+	MEDIA_BUS_FMT_SBGGR8_1X8, MEDIA_BUS_FMT_SGBRG8_1X8,
+	MEDIA_BUS_FMT_SGRBG8_1X8, MEDIA_BUS_FMT_SRGGB8_1X8,
+	MEDIA_BUS_FMT_SBGGR10_1X10, MEDIA_BUS_FMT_SGBRG10_1X10,
+	MEDIA_BUS_FMT_SGRBG10_1X10, MEDIA_BUS_FMT_SRGGB10_1X10,
+	MEDIA_BUS_FMT_SBGGR12_1X12, MEDIA_BUS_FMT_SGBRG12_1X12,
+	MEDIA_BUS_FMT_SGRBG12_1X12, MEDIA_BUS_FMT_SRGGB12_1X12,
+	MEDIA_BUS_FMT_UYVY8_1X16, MEDIA_BUS_FMT_BGR888_1X24
+};
+
+/* regulator supplies */
+static const char * const mipid02_supply_name[] = {
+	"VDDE", /* 1.8V digital I/O supply */
+	"VDDIN", /* 1V8 voltage regulator supply */
+};
+
+#define MIPID02_NUM_SUPPLIES		ARRAY_SIZE(mipid02_supply_name)
+
+#define MIPID02_SINK_0			0
+#define MIPID02_SINK_1			1
+#define MIPID02_SOURCE			2
+#define MIPID02_PAD_NB			3
+
+struct mipid02_dev {
+	struct i2c_client *i2c_client;
+	struct regulator_bulk_data supplies[MIPID02_NUM_SUPPLIES];
+	struct v4l2_subdev sd;
+	struct media_pad pad[MIPID02_PAD_NB];
+	struct clk *xclk;
+	struct gpio_desc *reset_gpio;
+	/* endpoints info */
+	struct v4l2_fwnode_endpoint rx;
+	u64 link_frequency;
+	struct v4l2_fwnode_endpoint tx;
+	/* remote source */
+	struct v4l2_async_subdev asd;
+	struct v4l2_async_notifier notifier;
+	struct v4l2_subdev *s_subdev;
+	/* registers */
+	struct {
+		u8 clk_lane_reg1;
+		u8 data_lane0_reg1;
+		u8 data_lane1_reg1;
+		u8 mode_reg1;
+		u8 mode_reg2;
+		u8 data_id_rreg;
+		u8 pix_width_ctrl;
+		u8 pix_width_ctrl_emb;
+	} r;
+	/* lock to protect all members below */
+	struct mutex lock;
+	bool streaming;
+	struct v4l2_mbus_framefmt fmt;
+};
+
+static int bpp_from_code(__u32 code)
+{
+	switch (code) {
+	case MEDIA_BUS_FMT_SBGGR8_1X8:
+	case MEDIA_BUS_FMT_SGBRG8_1X8:
+	case MEDIA_BUS_FMT_SGRBG8_1X8:
+	case MEDIA_BUS_FMT_SRGGB8_1X8:
+		return 8;
+	case MEDIA_BUS_FMT_SBGGR10_1X10:
+	case MEDIA_BUS_FMT_SGBRG10_1X10:
+	case MEDIA_BUS_FMT_SGRBG10_1X10:
+	case MEDIA_BUS_FMT_SRGGB10_1X10:
+		return 10;
+	case MEDIA_BUS_FMT_SBGGR12_1X12:
+	case MEDIA_BUS_FMT_SGBRG12_1X12:
+	case MEDIA_BUS_FMT_SGRBG12_1X12:
+	case MEDIA_BUS_FMT_SRGGB12_1X12:
+		return 12;
+	case MEDIA_BUS_FMT_UYVY8_1X16:
+		return 16;
+	case MEDIA_BUS_FMT_BGR888_1X24:
+		return 24;
+	default:
+		return 0;
+	}
+}
+
+static u8 data_type_from_code(__u32 code)
+{
+	switch (code) {
+	case MEDIA_BUS_FMT_SBGGR8_1X8:
+	case MEDIA_BUS_FMT_SGBRG8_1X8:
+	case MEDIA_BUS_FMT_SGRBG8_1X8:
+	case MEDIA_BUS_FMT_SRGGB8_1X8:
+		return 0x2a;
+	case MEDIA_BUS_FMT_SBGGR10_1X10:
+	case MEDIA_BUS_FMT_SGBRG10_1X10:
+	case MEDIA_BUS_FMT_SGRBG10_1X10:
+	case MEDIA_BUS_FMT_SRGGB10_1X10:
+		return 0x2b;
+	case MEDIA_BUS_FMT_SBGGR12_1X12:
+	case MEDIA_BUS_FMT_SGBRG12_1X12:
+	case MEDIA_BUS_FMT_SGRBG12_1X12:
+	case MEDIA_BUS_FMT_SRGGB12_1X12:
+		return 0x2c;
+	case MEDIA_BUS_FMT_UYVY8_1X16:
+		return 0x1e;
+	case MEDIA_BUS_FMT_BGR888_1X24:
+		return 0x24;
+	default:
+		return 0;
+	}
+}
+
+static void init_format(struct v4l2_mbus_framefmt *fmt)
+{
+	fmt->code = MEDIA_BUS_FMT_SBGGR8_1X8;
+	fmt->field = V4L2_FIELD_NONE;
+	fmt->colorspace = V4L2_COLORSPACE_SRGB;
+	fmt->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(V4L2_COLORSPACE_SRGB);
+	fmt->quantization = V4L2_QUANTIZATION_FULL_RANGE;
+	fmt->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(V4L2_COLORSPACE_SRGB);
+	fmt->width = 640;
+	fmt->height = 480;
+}
+
+static __u32 get_fmt_code(__u32 code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(mipid02_supported_fmt_codes); i++) {
+		if (code == mipid02_supported_fmt_codes[i])
+			return code;
+	}
+
+	return mipid02_supported_fmt_codes[0];
+}
+
+static __u32 serial_to_parallel_code(__u32 serial)
+{
+	if (serial == MEDIA_BUS_FMT_UYVY8_1X16)
+		return MEDIA_BUS_FMT_UYVY8_2X8;
+
+	return serial;
+}
+
+static inline struct mipid02_dev *to_mipid02_dev(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct mipid02_dev, sd);
+}
+
+static int mipid02_read_reg(struct mipid02_dev *bridge, u16 reg, u8 *val)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	struct i2c_msg msg[2];
+	u8 buf[2];
+	int ret;
+
+	buf[0] = reg >> 8;
+	buf[1] = reg & 0xff;
+
+	msg[0].addr = client->addr;
+	msg[0].flags = client->flags;
+	msg[0].buf = buf;
+	msg[0].len = sizeof(buf);
+
+	msg[1].addr = client->addr;
+	msg[1].flags = client->flags | I2C_M_RD;
+	msg[1].buf = val;
+	msg[1].len = 1;
+
+	ret = i2c_transfer(client->adapter, msg, 2);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "%s: %x i2c_transfer, reg: %x => %d\n",
+			    __func__, client->addr, reg, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mipid02_write_reg(struct mipid02_dev *bridge, u16 reg, u8 val)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	struct i2c_msg msg;
+	u8 buf[3];
+	int ret;
+
+	buf[0] = reg >> 8;
+	buf[1] = reg & 0xff;
+	buf[2] = val;
+
+	msg.addr = client->addr;
+	msg.flags = client->flags;
+	msg.buf = buf;
+	msg.len = sizeof(buf);
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "%s: i2c_transfer, reg: %x => %d\n",
+			    __func__, reg, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mipid02_get_regulators(struct mipid02_dev *bridge)
+{
+	unsigned int i;
+
+	for (i = 0; i < MIPID02_NUM_SUPPLIES; i++)
+		bridge->supplies[i].supply = mipid02_supply_name[i];
+
+	return devm_regulator_bulk_get(&bridge->i2c_client->dev,
+				       MIPID02_NUM_SUPPLIES,
+				       bridge->supplies);
+}
+
+static void mipid02_apply_reset(struct mipid02_dev *bridge)
+{
+	gpiod_set_value_cansleep(bridge->reset_gpio, 0);
+	usleep_range(5000, 10000);
+	gpiod_set_value_cansleep(bridge->reset_gpio, 1);
+	usleep_range(5000, 10000);
+	gpiod_set_value_cansleep(bridge->reset_gpio, 0);
+	usleep_range(5000, 10000);
+}
+
+static int mipid02_set_power_on(struct mipid02_dev *bridge)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	int ret;
+
+	ret = clk_prepare_enable(bridge->xclk);
+	if (ret) {
+		dev_err(&client->dev, "%s: failed to enable clock\n", __func__);
+		return ret;
+	}
+
+	ret = regulator_bulk_enable(MIPID02_NUM_SUPPLIES,
+				    bridge->supplies);
+	if (ret) {
+		dev_err(&client->dev, "%s: failed to enable regulators\n",
+			    __func__);
+		goto xclk_off;
+	}
+
+	if (bridge->reset_gpio) {
+		dev_dbg(&client->dev, "apply reset");
+		mipid02_apply_reset(bridge);
+	} else {
+		dev_dbg(&client->dev, "don't apply reset");
+		usleep_range(5000, 10000);
+	}
+
+	return 0;
+
+xclk_off:
+	clk_disable_unprepare(bridge->xclk);
+	return ret;
+}
+
+static void mipid02_set_power_off(struct mipid02_dev *bridge)
+{
+	regulator_bulk_disable(MIPID02_NUM_SUPPLIES, bridge->supplies);
+	clk_disable_unprepare(bridge->xclk);
+}
+
+static int mipid02_detect(struct mipid02_dev *bridge)
+{
+	u8 reg;
+
+	/*
+	 * There is no version registers. Just try to read register
+	 * MIPID02_CLK_LANE_WR_REG1.
+	 */
+	return mipid02_read_reg(bridge, MIPID02_CLK_LANE_WR_REG1, &reg);
+}
+
+static u32 mipid02_get_link_freq_from_cid_pixel_rate(struct mipid02_dev *bridge,
+						     struct v4l2_subdev *subdev)
+{
+	struct v4l2_fwnode_endpoint *ep = &bridge->rx;
+	struct v4l2_ctrl *ctrl;
+	u32 pixel_clock;
+	u32 bpp = bpp_from_code(bridge->fmt.code);
+
+	ctrl = v4l2_ctrl_find(subdev->ctrl_handler, V4L2_CID_PIXEL_RATE);
+	if (!ctrl)
+		return 0;
+	pixel_clock = v4l2_ctrl_g_ctrl_int64(ctrl);
+
+	return pixel_clock * bpp / (2 * ep->bus.mipi_csi2.num_data_lanes);
+}
+
+/*
+ * We need to know link frequency to setup clk_lane_reg1 timings. Link frequency
+ * will be computed using connected device V4L2_CID_PIXEL_RATE, bit per pixel
+ * and number of lanes.
+ */
+static int mipid02_configure_from_rx_speed(struct mipid02_dev *bridge)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	struct v4l2_subdev *subdev = bridge->s_subdev;
+	u32 link_freq;
+
+	link_freq = mipid02_get_link_freq_from_cid_pixel_rate(bridge, subdev);
+	if (!link_freq) {
+		dev_err(&client->dev, "Failed to detect link frequency");
+		return -EINVAL;
+	}
+
+	dev_dbg(&client->dev, "detect link_freq = %d Hz", link_freq);
+	bridge->r.clk_lane_reg1 |= (2000000000 / link_freq) << 2;
+
+	return 0;
+}
+
+static int mipid02_configure_clk_lane(struct mipid02_dev *bridge)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	struct v4l2_fwnode_endpoint *ep = &bridge->rx;
+	bool *polarities = ep->bus.mipi_csi2.lane_polarities;
+
+	/* midid02 doesn't support clock lane remapping */
+	if (ep->bus.mipi_csi2.clock_lane != 0) {
+		dev_err(&client->dev, "clk lane must be map to lane 0\n");
+		return -EINVAL;
+	}
+	bridge->r.clk_lane_reg1 |= (polarities[0] << 1) | CLK_ENABLE;
+
+	return 0;
+}
+
+static int mipid02_configure_data0_lane(struct mipid02_dev *bridge, int nb,
+					bool are_lanes_swap, bool *polarities)
+{
+	bool are_pin_swap = are_lanes_swap ? polarities[2] : polarities[1];
+
+	if (nb == 1 && are_lanes_swap)
+		return 0;
+
+	/*
+	 * data lane 0 as pin swap polarity reversed compared to clock and
+	 * data lane 1
+	 */
+	if (!are_pin_swap)
+		bridge->r.data_lane0_reg1 = 1 << 1;
+	bridge->r.data_lane0_reg1 |= DATA_ENABLE;
+
+	return 0;
+}
+
+static int mipid02_configure_data1_lane(struct mipid02_dev *bridge, int nb,
+					bool are_lanes_swap, bool *polarities)
+{
+	bool are_pin_swap = are_lanes_swap ? polarities[1] : polarities[2];
+
+	if (nb == 1 && !are_lanes_swap)
+		return 0;
+
+	if (are_pin_swap)
+		bridge->r.data_lane1_reg1 = 1 << 1;
+	bridge->r.data_lane1_reg1 |= DATA_ENABLE;
+
+	return 0;
+}
+
+static int mipid02_configure_from_rx(struct mipid02_dev *bridge)
+{
+	struct v4l2_fwnode_endpoint *ep = &bridge->rx;
+	bool are_lanes_swap = ep->bus.mipi_csi2.data_lanes[0] == 2;
+	bool *polarities = ep->bus.mipi_csi2.lane_polarities;
+	int nb = ep->bus.mipi_csi2.num_data_lanes;
+	int ret;
+
+	ret = mipid02_configure_clk_lane(bridge);
+	if (ret)
+		return ret;
+
+	ret = mipid02_configure_data0_lane(bridge, nb, are_lanes_swap,
+					   polarities);
+	if (ret)
+		return ret;
+
+	ret = mipid02_configure_data1_lane(bridge, nb, are_lanes_swap,
+					   polarities);
+	if (ret)
+		return ret;
+
+	bridge->r.mode_reg1 |= are_lanes_swap ? MODE_DATA_SWAP : 0;
+	bridge->r.mode_reg1 |= (nb - 1) << 1;
+
+	return mipid02_configure_from_rx_speed(bridge);
+}
+
+static int mipid02_configure_from_tx(struct mipid02_dev *bridge)
+{
+	struct v4l2_fwnode_endpoint *ep = &bridge->tx;
+
+	bridge->r.pix_width_ctrl = ep->bus.parallel.bus_width;
+	bridge->r.pix_width_ctrl_emb = ep->bus.parallel.bus_width;
+	if (ep->bus.parallel.flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
+		bridge->r.mode_reg2 |= MODE_HSYNC_ACTIVE_HIGH;
+	if (ep->bus.parallel.flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
+		bridge->r.mode_reg2 |= MODE_VSYNC_ACTIVE_HIGH;
+
+	return 0;
+}
+
+static int mipid02_configure_from_code(struct mipid02_dev *bridge)
+{
+	u8 data_type;
+
+	bridge->r.data_id_rreg = 0;
+	data_type = data_type_from_code(bridge->fmt.code);
+	if (!data_type)
+		return -EINVAL;
+	bridge->r.data_id_rreg = data_type;
+
+	return 0;
+}
+
+static int mipid02_stream_disable(struct mipid02_dev *bridge)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	int ret;
+
+	/* Disable all lanes */
+	ret = mipid02_write_reg(bridge, MIPID02_CLK_LANE_REG1, 0);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_LANE0_REG1, 0);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_LANE1_REG1, 0);
+	if (ret)
+		goto error;
+error:
+	if (ret)
+		dev_err(&client->dev, "failed to stream off %d", ret);
+
+	return ret;
+}
+
+static int mipid02_stream_enable(struct mipid02_dev *bridge)
+{
+	struct i2c_client *client = bridge->i2c_client;
+	int ret = -EINVAL;
+
+	if (!bridge->s_subdev)
+		goto error;
+
+	memset(&bridge->r, 0, sizeof(bridge->r));
+	/* build registers content */
+	ret = mipid02_configure_from_rx(bridge);
+	if (ret)
+		goto error;
+	ret = mipid02_configure_from_tx(bridge);
+	if (ret)
+		goto error;
+	ret = mipid02_configure_from_code(bridge);
+	if (ret)
+		goto error;
+
+	/* write mipi registers */
+	ret = mipid02_write_reg(bridge, MIPID02_CLK_LANE_REG1,
+		bridge->r.clk_lane_reg1);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_CLK_LANE_REG3, CLK_MIPI_CSI);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_LANE0_REG1,
+		bridge->r.data_lane0_reg1);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_LANE0_REG2,
+		DATA_MIPI_CSI);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_LANE1_REG1,
+		bridge->r.data_lane1_reg1);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_LANE1_REG2,
+		DATA_MIPI_CSI);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_MODE_REG1,
+		MODE_NO_BYPASS | bridge->r.mode_reg1);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_MODE_REG2,
+		bridge->r.mode_reg2);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_ID_RREG,
+		bridge->r.data_id_rreg);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_DATA_SELECTION_CTRL,
+		SELECTION_MANUAL_DATA | SELECTION_MANUAL_WIDTH);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_PIX_WIDTH_CTRL,
+		bridge->r.pix_width_ctrl);
+	if (ret)
+		goto error;
+	ret = mipid02_write_reg(bridge, MIPID02_PIX_WIDTH_CTRL_EMB,
+		bridge->r.pix_width_ctrl_emb);
+	if (ret)
+		goto error;
+
+	return 0;
+
+error:
+	dev_err(&client->dev, "failed to stream on %d", ret);
+	mipid02_stream_disable(bridge);
+
+	return ret;
+}
+
+static int mipid02_s_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+	struct i2c_client *client = bridge->i2c_client;
+	int ret = 0;
+
+	dev_dbg(&client->dev, "%s : requested %d / current = %d", __func__,
+		    enable, bridge->streaming);
+	mutex_lock(&bridge->lock);
+
+	if (bridge->streaming == enable)
+		goto out;
+
+	ret = enable ? mipid02_stream_enable(bridge) :
+		       mipid02_stream_disable(bridge);
+	if (!ret)
+		bridge->streaming = enable;
+
+out:
+	dev_dbg(&client->dev, "%s current now = %d / %d", __func__,
+		    bridge->streaming, ret);
+	mutex_unlock(&bridge->lock);
+
+	return ret;
+}
+
+static int mipid02_enum_mbus_code(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_pad_config *cfg,
+				 struct v4l2_subdev_mbus_code_enum *code)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+	int ret = 0;
+
+	switch (code->pad) {
+	case MIPID02_SINK_0:
+		if (code->index >= ARRAY_SIZE(mipid02_supported_fmt_codes))
+			ret = -EINVAL;
+		else
+			code->code = mipid02_supported_fmt_codes[code->index];
+		break;
+	case MIPID02_SOURCE:
+		if (code->index == 0)
+			code->code = serial_to_parallel_code(bridge->fmt.code);
+		else
+			ret = -EINVAL;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int mipid02_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *format)
+{
+	struct v4l2_mbus_framefmt *mbus_fmt = &format->format;
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+	struct i2c_client *client = bridge->i2c_client;
+	struct v4l2_mbus_framefmt *fmt;
+
+	dev_dbg(&client->dev, "%s probe %d", __func__, format->pad);
+
+	if (format->pad >= MIPID02_PAD_NB)
+		return -EINVAL;
+	/* second CSI-2 pad not yet supported */
+	if (format->pad == MIPID02_SINK_1)
+		return -EINVAL;
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
+		fmt = v4l2_subdev_get_try_format(&bridge->sd, cfg, format->pad);
+	else
+		fmt = &bridge->fmt;
+
+	mutex_lock(&bridge->lock);
+
+	*mbus_fmt = *fmt;
+	/* code may need to be converted for source */
+	if (format->pad == MIPID02_SOURCE)
+		mbus_fmt->code = serial_to_parallel_code(mbus_fmt->code);
+
+	mutex_unlock(&bridge->lock);
+
+	return 0;
+}
+
+static void mipid02_set_fmt_source(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_pad_config *cfg,
+				   struct v4l2_subdev_format *format)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+
+	/* source pad mirror active sink pad */
+	format->format = bridge->fmt;
+	/* but code may need to be converted */
+	format->format.code = serial_to_parallel_code(format->format.code);
+
+	/* only apply format for V4L2_SUBDEV_FORMAT_TRY case */
+	if (format->which != V4L2_SUBDEV_FORMAT_TRY)
+		return;
+
+	*v4l2_subdev_get_try_format(sd, cfg, format->pad) = format->format;
+}
+
+static void mipid02_set_fmt_sink(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_pad_config *cfg,
+				 struct v4l2_subdev_format *format)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+	struct v4l2_mbus_framefmt *fmt;
+
+	format->format.code = get_fmt_code(format->format.code);
+
+	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
+		fmt = v4l2_subdev_get_try_format(sd, cfg, format->pad);
+	else
+		fmt = &bridge->fmt;
+
+	*fmt = format->format;
+}
+
+static int mipid02_set_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *format)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+	struct i2c_client *client = bridge->i2c_client;
+	int ret = 0;
+
+	dev_dbg(&client->dev, "%s for %d", __func__, format->pad);
+
+	if (format->pad >= MIPID02_PAD_NB)
+		return -EINVAL;
+	/* second CSI-2 pad not yet supported */
+	if (format->pad == MIPID02_SINK_1)
+		return -EINVAL;
+
+	mutex_lock(&bridge->lock);
+
+	if (bridge->streaming) {
+		ret = -EBUSY;
+		goto error;
+	}
+
+	if (format->pad == MIPID02_SOURCE)
+		mipid02_set_fmt_source(sd, cfg, format);
+	else
+		mipid02_set_fmt_sink(sd, cfg, format);
+
+error:
+	mutex_unlock(&bridge->lock);
+
+	return ret;
+}
+
+static const struct v4l2_subdev_video_ops mipid02_video_ops = {
+	.s_stream = mipid02_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops mipid02_pad_ops = {
+	.enum_mbus_code = mipid02_enum_mbus_code,
+	.get_fmt = mipid02_get_fmt,
+	.set_fmt = mipid02_set_fmt,
+};
+
+static const struct v4l2_subdev_ops mipid02_subdev_ops = {
+	.video = &mipid02_video_ops,
+	.pad = &mipid02_pad_ops,
+};
+
+static const struct media_entity_operations mipid02_subdev_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static int mipid02_async_bound(struct v4l2_async_notifier *notifier,
+			       struct v4l2_subdev *s_subdev,
+			       struct v4l2_async_subdev *asd)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(notifier->sd);
+	struct i2c_client *client = bridge->i2c_client;
+	int source_pad;
+	int ret;
+
+	dev_dbg(&client->dev, "sensor_async_bound call %p", s_subdev);
+
+	source_pad = media_entity_get_fwnode_pad(&s_subdev->entity,
+						 s_subdev->fwnode,
+						 MEDIA_PAD_FL_SOURCE);
+	if (source_pad < 0) {
+		dev_err(&client->dev, "Couldn't find output pad for subdev %s\n",
+			s_subdev->name);
+		return source_pad;
+	}
+
+	ret = media_create_pad_link(&s_subdev->entity, source_pad,
+				    &bridge->sd.entity, 0,
+				    MEDIA_LNK_FL_ENABLED |
+				    MEDIA_LNK_FL_IMMUTABLE);
+	if (ret) {
+		dev_err(&client->dev, "Couldn't create media link %d", ret);
+		return ret;
+	}
+
+	bridge->s_subdev = s_subdev;
+
+	return 0;
+}
+
+static void mipid02_async_unbind(struct v4l2_async_notifier *notifier,
+				 struct v4l2_subdev *s_subdev,
+				 struct v4l2_async_subdev *asd)
+{
+	struct mipid02_dev *bridge = to_mipid02_dev(notifier->sd);
+
+	bridge->s_subdev = NULL;
+}
+
+static const struct v4l2_async_notifier_operations mipid02_notifier_ops = {
+	.bound		= mipid02_async_bound,
+	.unbind		= mipid02_async_unbind,
+};
+
+static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
+{
+	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
+	struct i2c_client *client = bridge->i2c_client;
+	struct device_node *ep_node;
+	int ret;
+
+	/* parse rx (endpoint 0) */
+	ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
+						0, 0);
+	if (!ep_node) {
+		dev_err(&client->dev, "unable to find port0 ep");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(of_fwnode_handle(ep_node), &ep);
+	if (ret) {
+		dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
+			ret);
+		goto error_of_node_put;
+	}
+
+	/* do some sanity checks */
+	if (ep.bus.mipi_csi2.num_data_lanes > 2) {
+		dev_err(&client->dev, "max supported data lanes is 2 / got %d",
+			ep.bus.mipi_csi2.num_data_lanes);
+		ret = -EINVAL;
+		goto error_v4l2_fwnode_endpoint_free;
+	}
+
+	/* register it for later use */
+	bridge->rx = ep;
+	v4l2_fwnode_endpoint_free(&ep);
+
+	/* register async notifier so we get noticed when sensor is connected */
+	bridge->asd.match.fwnode =
+		fwnode_graph_get_remote_port_parent(of_fwnode_handle(ep_node));
+	bridge->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+	of_node_put(ep_node);
+
+	v4l2_async_notifier_init(&bridge->notifier);
+	ret = v4l2_async_notifier_add_subdev(&bridge->notifier, &bridge->asd);
+	if (ret) {
+		dev_err(&client->dev, "fail to register asd to notifier %d",
+			ret);
+		goto error_fwnode_handle_put;
+	}
+	bridge->notifier.ops = &mipid02_notifier_ops;
+
+	ret = v4l2_async_subdev_notifier_register(&bridge->sd,
+						  &bridge->notifier);
+	if (ret)
+		v4l2_async_notifier_cleanup(&bridge->notifier);
+
+	return ret;
+
+error_v4l2_fwnode_endpoint_free:
+	v4l2_fwnode_endpoint_free(&ep);
+error_of_node_put:
+	of_node_put(ep_node);
+error:
+
+	return ret;
+
+error_fwnode_handle_put:
+	fwnode_handle_put(bridge->asd.match.fwnode);
+
+	return ret;
+}
+
+static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
+{
+	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
+	struct i2c_client *client = bridge->i2c_client;
+	struct device_node *ep_node;
+	int ret;
+
+	/* parse tx (endpoint 2) */
+	ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
+						2, 0);
+	if (!ep_node) {
+		dev_err(&client->dev, "unable to find port1 ep");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
+	if (ret) {
+		dev_err(&client->dev, "Could not parse v4l2 endpoint\n");
+		goto error_of_node_put;
+	}
+
+	of_node_put(ep_node);
+	bridge->tx = ep;
+
+	return 0;
+
+error_of_node_put:
+	of_node_put(ep_node);
+error:
+
+	return -EINVAL;
+}
+
+static int mipid02_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct mipid02_dev *bridge;
+	u32 clk_freq;
+	int ret;
+
+	bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
+	if (!bridge)
+		return -ENOMEM;
+
+	init_format(&bridge->fmt);
+
+	bridge->i2c_client = client;
+	v4l2_i2c_subdev_init(&bridge->sd, client, &mipid02_subdev_ops);
+
+	/* got and check clock */
+	bridge->xclk = devm_clk_get(dev, "xclk");
+	if (IS_ERR(bridge->xclk)) {
+		dev_err(dev, "failed to get xclk\n");
+		return PTR_ERR(bridge->xclk);
+	}
+
+	clk_freq = clk_get_rate(bridge->xclk);
+	if (clk_freq < 6000000 || clk_freq > 27000000) {
+		dev_err(dev, "xclk freq must be in 6-27 Mhz range. got %d Hz\n",
+			clk_freq);
+		return -EINVAL;
+	}
+
+	bridge->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						     GPIOD_OUT_HIGH);
+
+	ret = mipid02_get_regulators(bridge);
+	if (ret) {
+		dev_err(dev, "failed to get regulators %d", ret);
+		return ret;
+	}
+
+	mutex_init(&bridge->lock);
+	bridge->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	bridge->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+	bridge->sd.entity.ops = &mipid02_subdev_entity_ops;
+	bridge->pad[0].flags = MEDIA_PAD_FL_SINK;
+	bridge->pad[1].flags = MEDIA_PAD_FL_SINK;
+	bridge->pad[2].flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&bridge->sd.entity, MIPID02_PAD_NB,
+				     bridge->pad);
+	if (ret) {
+		dev_err(&client->dev, "pads init failed %d", ret);
+		return ret;
+	}
+
+	/* enable clock, power and reset device if available */
+	ret = mipid02_set_power_on(bridge);
+	if (ret)
+		goto entity_cleanup;
+
+	ret = mipid02_detect(bridge);
+	if (ret) {
+		dev_err(&client->dev, "failed to detect mipid02 %d", ret);
+		goto power_off;
+	}
+
+	ret = mipid02_parse_tx_ep(bridge);
+	if (ret) {
+		dev_err(&client->dev, "failed to parse tx %d", ret);
+		goto power_off;
+	}
+
+	ret = mipid02_parse_rx_ep(bridge);
+	if (ret) {
+		dev_err(&client->dev, "failed to parse rx %d", ret);
+		goto power_off;
+	}
+
+	ret = v4l2_async_register_subdev(&bridge->sd);
+	if (ret < 0) {
+		dev_err(&client->dev, "v4l2_async_register_subdev failed %d",
+			    ret);
+		goto unregister_notifier;
+	}
+
+	dev_info(&client->dev, "mipid02 device probe successfully");
+
+	return 0;
+
+unregister_notifier:
+	v4l2_async_notifier_unregister(&bridge->notifier);
+	v4l2_async_notifier_cleanup(&bridge->notifier);
+power_off:
+	mipid02_set_power_off(bridge);
+entity_cleanup:
+	media_entity_cleanup(&bridge->sd.entity);
+
+	return ret;
+}
+
+static int mipid02_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct mipid02_dev *bridge = to_mipid02_dev(sd);
+
+	v4l2_async_notifier_unregister(&bridge->notifier);
+	v4l2_async_notifier_cleanup(&bridge->notifier);
+	v4l2_async_unregister_subdev(&bridge->sd);
+	mipid02_set_power_off(bridge);
+	media_entity_cleanup(&bridge->sd.entity);
+
+	return 0;
+}
+
+static const struct i2c_device_id mipid02_id[] = {
+	{ "st-mipid02", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, mipid02_id);
+
+static const struct of_device_id mipid02_dt_ids[] = {
+	{ .compatible = "st,st-mipid02" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mipid02_dt_ids);
+
+static struct i2c_driver mipid02_i2c_driver = {
+	.driver = {
+		.name  = "st-mipid02",
+		.of_match_table = mipid02_dt_ids,
+	},
+	.id_table = mipid02_id,
+	.probe    = mipid02_probe,
+	.remove   = mipid02_remove,
+};
+
+module_i2c_driver(mipid02_i2c_driver);
+
+MODULE_AUTHOR("Mickael Guene <mickael.guene@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics MIPID02 CSI-2 bridge driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4