Re: [PATCH v8 2/3] media: imx: add a driver for i.MX8MQ mipi csi rx phy and controller

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Martin,

Thank you for the patch.

On Fri, Jul 23, 2021 at 12:12:16PM +0200, Martin Kepplinger wrote:
> Add a driver to support the i.MX8MQ MIPI CSI receiver. The hardware side
> is based on
> https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/media/platform/imx8/mxc-mipi-csi2_yav.c?h=imx_5.4.70_2.3.0
> 
> It's built as part of VIDEO_IMX7_CSI because that's documented to support
> i.MX8M platforms. This driver adds i.MX8MQ support where currently only the
> i.MX8MM platform has been supported.
> 
> Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/staging/media/imx/Makefile           |   1 +
>  drivers/staging/media/imx/imx8mq-mipi-csi2.c | 979 +++++++++++++++++++
>  2 files changed, 980 insertions(+)
>  create mode 100644 drivers/staging/media/imx/imx8mq-mipi-csi2.c
> 
> diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile
> index 6ac33275cc97..19c2fc54d424 100644
> --- a/drivers/staging/media/imx/Makefile
> +++ b/drivers/staging/media/imx/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_VIDEO_IMX_CSI) += imx6-mipi-csi2.o
>  
>  obj-$(CONFIG_VIDEO_IMX7_CSI) += imx7-media-csi.o
>  obj-$(CONFIG_VIDEO_IMX7_CSI) += imx7-mipi-csis.o
> +obj-$(CONFIG_VIDEO_IMX7_CSI) += imx8mq-mipi-csi2.o
> diff --git a/drivers/staging/media/imx/imx8mq-mipi-csi2.c b/drivers/staging/media/imx/imx8mq-mipi-csi2.c
> new file mode 100644
> index 000000000000..7468ed856d41
> --- /dev/null
> +++ b/drivers/staging/media/imx/imx8mq-mipi-csi2.c
> @@ -0,0 +1,979 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * NXP i.MX8MQ SoC series MIPI-CSI2 receiver driver
> + *
> + * Copyright (C) 2021 Purism SPC
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/interconnect.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
> +#include <linux/spinlock.h>
> +
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
> +#include <media/v4l2-mc.h>
> +#include <media/v4l2-subdev.h>
> +
> +#define MIPI_CSI2_DRIVER_NAME			"imx8mq-mipi-csi2"
> +#define MIPI_CSI2_SUBDEV_NAME			MIPI_CSI2_DRIVER_NAME
> +
> +#define MIPI_CSI2_PAD_SINK			0
> +#define MIPI_CSI2_PAD_SOURCE			1
> +#define MIPI_CSI2_PADS_NUM			2
> +
> +#define MIPI_CSI2_DEF_PIX_WIDTH			640
> +#define MIPI_CSI2_DEF_PIX_HEIGHT		480
> +
> +/* Register map definition */
> +
> +/* i.MX8MQ CSI-2 controller CSR */
> +#define CSI2RX_CFG_NUM_LANES			0x100
> +#define CSI2RX_CFG_DISABLE_DATA_LANES		0x104
> +#define CSI2RX_BIT_ERR				0x108
> +#define CSI2RX_IRQ_STATUS			0x10c
> +#define CSI2RX_IRQ_MASK				0x110
> +#define CSI2RX_IRQ_MASK_ALL			0x1ff
> +#define CSI2RX_IRQ_MASK_ULPS_STATUS_CHANGE	0x8
> +#define CSI2RX_ULPS_STATUS			0x114
> +#define CSI2RX_PPI_ERRSOT_HS			0x118
> +#define CSI2RX_PPI_ERRSOTSYNC_HS		0x11c
> +#define CSI2RX_PPI_ERRESC			0x120
> +#define CSI2RX_PPI_ERRSYNCESC			0x124
> +#define CSI2RX_PPI_ERRCONTROL			0x128
> +#define CSI2RX_CFG_DISABLE_PAYLOAD_0		0x12c
> +#define CSI2RX_CFG_VID_P_FIFO_SEND_LEVEL	0x188
> +#define CSI2RX_CFG_DISABLE_PAYLOAD_1		0x130
> +
> +enum {
> +	ST_POWERED	= 1,
> +	ST_STREAMING	= 2,
> +	ST_SUSPENDED	= 4,
> +};
> +
> +static const char * const imx8mq_mipi_csi_clk_id[] = {
> +	"core",
> +	"esc",
> +	"ui",
> +};
> +
> +#define CSI2_NUM_CLKS	ARRAY_SIZE(imx8mq_mipi_csi_clk_id)
> +
> +#define	GPR_CSI2_1_RX_ENABLE		BIT(13)
> +#define	GPR_CSI2_1_VID_INTFC_ENB	BIT(12)
> +#define	GPR_CSI2_1_HSEL			BIT(10)
> +#define	GPR_CSI2_1_CONT_CLK_MODE	BIT(8)
> +#define	GPR_CSI2_1_S_PRG_RXHS_SETTLE(x)	(((x) & 0x3f) << 2)
> +
> +/*
> + * The send level configures the number of entries that must accumulate in
> + * the Pixel FIFO before the data will be transferred to the video output.
> + * See https://community.nxp.com/t5/i-MX-Processors/IMX8M-MIPI-CSI-Host-Controller-send-level/m-p/864005/highlight/true#M131704
> + */
> +#define CSI2RX_SEND_LEVEL			64
> +
> +struct csi_state {
> +	struct device *dev;
> +	void __iomem *regs;
> +	struct clk_bulk_data clks[CSI2_NUM_CLKS];
> +	struct reset_control *rst;
> +	struct regulator *mipi_phy_regulator;
> +
> +	struct v4l2_subdev sd;
> +	struct media_pad pads[MIPI_CSI2_PADS_NUM];
> +	struct v4l2_async_notifier notifier;
> +	struct v4l2_subdev *src_sd;
> +
> +	struct v4l2_fwnode_bus_mipi_csi2 bus;
> +
> +	struct mutex lock; /* Protect csi2_fmt, format_mbus, state, hs_settle */
> +	const struct csi2_pix_format *csi2_fmt;
> +	struct v4l2_mbus_framefmt format_mbus[MIPI_CSI2_PADS_NUM];
> +	u32 state;
> +	u32 hs_settle;
> +
> +	struct regmap *phy_gpr;
> +	u8 phy_gpr_reg;
> +
> +	struct icc_path			*icc_path;
> +	s32				icc_path_bw;
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Format helpers
> + */
> +
> +struct csi2_pix_format {
> +	u32 code;
> +	u8 width;
> +};
> +
> +static const struct csi2_pix_format imx8mq_mipi_csi_formats[] = {
> +	/* RAW (Bayer and greyscale) formats. */
> +	{
> +		.code = MEDIA_BUS_FMT_SBGGR8_1X8,
> +		.width = 8,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGBRG8_1X8,
> +		.width = 8,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGRBG8_1X8,
> +		.width = 8,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SRGGB8_1X8,
> +		.width = 8,
> +	}, {
> +		.code = MEDIA_BUS_FMT_Y8_1X8,
> +		.width = 8,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SBGGR10_1X10,
> +		.width = 10,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGBRG10_1X10,
> +		.width = 10,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGRBG10_1X10,
> +		.width = 10,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SRGGB10_1X10,
> +		.width = 10,
> +	}, {
> +		.code = MEDIA_BUS_FMT_Y10_1X10,
> +		.width = 10,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SBGGR12_1X12,
> +		.width = 12,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGBRG12_1X12,
> +		.width = 12,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGRBG12_1X12,
> +		.width = 12,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SRGGB12_1X12,
> +		.width = 12,
> +	}, {
> +		.code = MEDIA_BUS_FMT_Y12_1X12,
> +		.width = 12,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SBGGR14_1X14,
> +		.width = 14,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGBRG14_1X14,
> +		.width = 14,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SGRBG14_1X14,
> +		.width = 14,
> +	}, {
> +		.code = MEDIA_BUS_FMT_SRGGB14_1X14,
> +		.width = 14,
> +	}, {
> +	/* YUV formats */
> +		.code = MEDIA_BUS_FMT_YUYV8_2X8,
> +		.width = 16,
> +	}, {
> +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> +		.width = 16,
> +	}
> +};
> +
> +static const struct csi2_pix_format *find_csi2_format(u32 code)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(imx8mq_mipi_csi_formats); i++)
> +		if (code == imx8mq_mipi_csi_formats[i].code)
> +			return &imx8mq_mipi_csi_formats[i];
> +	return NULL;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Hardware configuration
> + */
> +
> +static inline void imx8mq_mipi_csi_write(struct csi_state *state, u32 reg, u32 val)
> +{
> +	writel(val, state->regs + reg);
> +}
> +
> +static int imx8mq_mipi_csi_sw_reset(struct csi_state *state)
> +{
> +	int ret;
> +
> +	/*
> +	 * these are most likely self-clearing reset bits. to make it
> +	 * more clear, the reset-imx7 driver should implement the
> +	 * .reset() operation.
> +	 */
> +	ret = reset_control_assert(state->rst);
> +	if (ret < 0) {
> +		dev_err(state->dev, "Failed to assert resets: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void imx8mq_mipi_csi_system_enable(struct csi_state *state, int on)
> +{
> +	if (!on) {
> +		imx8mq_mipi_csi_write(state, CSI2RX_CFG_DISABLE_DATA_LANES, 0xf);
> +		return;
> +	}
> +
> +	regmap_update_bits(state->phy_gpr,
> +			   state->phy_gpr_reg,
> +			   0x3fff,
> +			   GPR_CSI2_1_RX_ENABLE |
> +			   GPR_CSI2_1_VID_INTFC_ENB |
> +			   GPR_CSI2_1_HSEL |
> +			   GPR_CSI2_1_CONT_CLK_MODE |
> +			   GPR_CSI2_1_S_PRG_RXHS_SETTLE(state->hs_settle));
> +}
> +
> +static void imx8mq_mipi_csi_set_params(struct csi_state *state)
> +{
> +	int lanes = state->bus.num_data_lanes;
> +
> +	imx8mq_mipi_csi_write(state, CSI2RX_CFG_NUM_LANES, lanes - 1);
> +	imx8mq_mipi_csi_write(state, CSI2RX_CFG_DISABLE_DATA_LANES,
> +			      (0xf << lanes) & 0xf);
> +	imx8mq_mipi_csi_write(state, CSI2RX_IRQ_MASK, CSI2RX_IRQ_MASK_ALL);
> +	imx8mq_mipi_csi_write(state, 0x180, 1);
> +	/* vid_vc */
> +	imx8mq_mipi_csi_write(state, 0x184, 1);
> +	imx8mq_mipi_csi_write(state, 0x188, CSI2RX_SEND_LEVEL);
> +}
> +
> +static int imx8mq_mipi_csi_clk_enable(struct csi_state *state)
> +{
> +	return clk_bulk_prepare_enable(CSI2_NUM_CLKS, state->clks);
> +}
> +
> +static void imx8mq_mipi_csi_clk_disable(struct csi_state *state)
> +{
> +	clk_bulk_disable_unprepare(CSI2_NUM_CLKS, state->clks);
> +}
> +
> +static int imx8mq_mipi_csi_clk_get(struct csi_state *state)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < CSI2_NUM_CLKS; i++)
> +		state->clks[i].id = imx8mq_mipi_csi_clk_id[i];
> +
> +	return devm_clk_bulk_get(state->dev, CSI2_NUM_CLKS, state->clks);
> +}
> +
> +static int imx8mq_mipi_csi_calc_hs_settle(struct csi_state *state)
> +{
> +	s64 link_freq;
> +	u32 lane_rate;
> +	u32 esc_clk_rate = 0;

This should be an unsigned long.

> +	u32 i, min_ths_settle, max_ths_settle, ths_settle_ns, esc_clk_period_ns;
> +	char *p;
> +
> +	/* Calculate the line rate from the pixel rate. */
> +	link_freq = v4l2_get_link_freq(state->src_sd->ctrl_handler,
> +				       state->csi2_fmt->width,
> +				       state->bus.num_data_lanes * 2);
> +	if (link_freq < 0) {
> +		dev_err(state->dev, "Unable to obtain link frequency: %d\n",
> +			(int)link_freq);
> +		return link_freq;
> +	}
> +
> +	lane_rate = link_freq * 2;
> +	if (lane_rate < 80000000 || lane_rate > 1500000000) {
> +		dev_dbg(state->dev, "Out-of-bound lane rate %u\n", lane_rate);
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * The D-PHY specification requires Ths-settle to be in the range
> +	 * 85ns + 6*UI to 140ns + 10*UI, with the unit interval UI being half
> +	 * the clock period.
> +	 *
> +	 * The Ths-settle value is expressed in the hardware as a multiple of
> +	 * the Esc clock period:
> +	 *
> +	 * Ths-settle = (PRG_RXHS_SETTLE + 1) * Tperiod of RxClkInEsc
> +	 *
> +	 * Due to the one cycle inaccuracy introduced by rounding, the
> +	 * documentation recommends picking a value away from the boundaries.
> +	 * Let's pick the average.
> +	 */
> +	for (i = 0; i < CSI2_NUM_CLKS; i++) {
> +		p = (char *)__clk_get_name(state->clks[i].clk);
> +
> +		dev_dbg(state->dev, "looking for esc clock: %s\n", p);
> +
> +		if (!strcmp(p, "esc") || !strcmp(p, "csi1_esc") ||
> +		    !strcmp(p, "csi2_esc"))
> +			esc_clk_rate = clk_get_rate(state->clks[i].clk);

The clocks are ordered in the state->clks array as in the
imx8mq_mipi_csi_clk_id array, so you can simply index the array instead
of checking the name. To avoid the risk of mismatch, you could write

enum imx8mq_mipi_csi_clk {
	CSI2_CLK_CORE,
	CSI2_CLK_ESC,
	CSI2_CLK_UI,
	CSI2_NUM_CLKS,
};

static const char * const imx8mq_mipi_csi_clk_id[CSI2_NUM_CLKS] = {
	[CSI2_CLK_CORE] = "core",
	[CSI2_CLK_ESC] = "esc",
	[CSI2_CLK_UI] = "ui",
};

and use 

	esc_clk_rate = clk_get_rate(state->clks[CSI2_CLK_ESC].clk);

here. No need to initialize esc_clk_rate to 0 above.

> +	}
> +
> +	if (!esc_clk_rate) {
> +		dev_err(state->dev, "Could not find esc clock.\n");

This would become "Could not get esc clock rate".

> +		return -EINVAL;
> +	}
> +
> +	dev_dbg(state->dev, "esc clk rate: %u\n", esc_clk_rate);

%lu

> +	esc_clk_period_ns = 1000000000 / esc_clk_rate;
> +
> +	min_ths_settle = 85 + 6 * 1000000 / (lane_rate / 1000);
> +	max_ths_settle = 140 + 10 * 1000000 / (lane_rate / 1000);
> +	ths_settle_ns = (min_ths_settle + max_ths_settle) / 2;
> +
> +	state->hs_settle = ths_settle_ns / esc_clk_period_ns - 1;
> +
> +	dev_dbg(state->dev, "lane rate %u Ths_settle %u hs_settle %u\n",
> +		lane_rate, ths_settle_ns, state->hs_settle);
> +
> +	return 0;
> +}
> +
> +static int imx8mq_mipi_csi_start_stream(struct csi_state *state)
> +{
> +	int ret;
> +
> +	ret = imx8mq_mipi_csi_sw_reset(state);
> +	if (ret)
> +		return ret;
> +
> +	imx8mq_mipi_csi_set_params(state);
> +	ret = imx8mq_mipi_csi_calc_hs_settle(state);
> +	if (ret)
> +		return ret;
> +
> +	imx8mq_mipi_csi_system_enable(state, true);
> +
> +	return 0;
> +}
> +
> +static void imx8mq_mipi_csi_stop_stream(struct csi_state *state)
> +{
> +	imx8mq_mipi_csi_system_enable(state, false);
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 subdev operations
> + */
> +
> +static struct csi_state *mipi_sd_to_csi2_state(struct v4l2_subdev *sdev)
> +{
> +	return container_of(sdev, struct csi_state, sd);
> +}
> +
> +static int imx8mq_mipi_csi_s_stream(struct v4l2_subdev *sd, int enable)
> +{
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +	int ret = 0;
> +
> +	imx8mq_mipi_csi_write(state, CSI2RX_IRQ_MASK,
> +			      CSI2RX_IRQ_MASK_ULPS_STATUS_CHANGE);
> +
> +	if (enable) {
> +		ret = pm_runtime_resume_and_get(state->dev);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	mutex_lock(&state->lock);
> +
> +	if (enable) {
> +		if (state->state & ST_SUSPENDED) {
> +			ret = -EBUSY;
> +			goto unlock;
> +		}
> +
> +		ret = imx8mq_mipi_csi_start_stream(state);
> +		if (ret < 0)
> +			goto unlock;
> +
> +		ret = v4l2_subdev_call(state->src_sd, video, s_stream, 1);
> +		if (ret < 0)
> +			goto unlock;
> +
> +		state->state |= ST_STREAMING;
> +	} else {
> +		v4l2_subdev_call(state->src_sd, video, s_stream, 0);
> +		imx8mq_mipi_csi_stop_stream(state);
> +		state->state &= ~ST_STREAMING;
> +	}
> +
> +unlock:
> +	mutex_unlock(&state->lock);
> +
> +	if (!enable || ret < 0)
> +		pm_runtime_put(state->dev);
> +
> +	return ret;
> +}
> +
> +static struct v4l2_mbus_framefmt *
> +imx8mq_mipi_csi_get_format(struct csi_state *state,
> +			   struct v4l2_subdev_state *sd_state,
> +			   enum v4l2_subdev_format_whence which,
> +			   unsigned int pad)
> +{
> +	if (which == V4L2_SUBDEV_FORMAT_TRY)
> +		return v4l2_subdev_get_try_format(&state->sd, sd_state, pad);
> +
> +	return &state->format_mbus[pad];
> +}
> +
> +static int imx8mq_mipi_csi_init_cfg(struct v4l2_subdev *sd,
> +				    struct v4l2_subdev_state *sd_state)
> +{
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +	struct v4l2_mbus_framefmt *fmt_sink;
> +	struct v4l2_mbus_framefmt *fmt_source;
> +	enum v4l2_subdev_format_whence which;
> +
> +	which = sd_state ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
> +	fmt_sink = imx8mq_mipi_csi_get_format(state, sd_state, which,
> +					      MIPI_CSI2_PAD_SINK);
> +
> +	fmt_sink->code = MEDIA_BUS_FMT_SGBRG10_1X10;
> +	fmt_sink->width = MIPI_CSI2_DEF_PIX_WIDTH;
> +	fmt_sink->height = MIPI_CSI2_DEF_PIX_HEIGHT;
> +	fmt_sink->field = V4L2_FIELD_NONE;
> +
> +	fmt_sink->colorspace = V4L2_COLORSPACE_RAW;
> +	fmt_sink->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(fmt_sink->colorspace);
> +	fmt_sink->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(fmt_sink->colorspace);
> +	fmt_sink->quantization =
> +		V4L2_MAP_QUANTIZATION_DEFAULT(false, fmt_sink->colorspace,
> +					      fmt_sink->ycbcr_enc);
> +
> +	fmt_source = imx8mq_mipi_csi_get_format(state, sd_state, which,
> +						MIPI_CSI2_PAD_SOURCE);
> +	*fmt_source = *fmt_sink;
> +
> +	return 0;
> +}
> +
> +static int imx8mq_mipi_csi_get_fmt(struct v4l2_subdev *sd,
> +				   struct v4l2_subdev_state *sd_state,
> +				   struct v4l2_subdev_format *sdformat)
> +{
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +	struct v4l2_mbus_framefmt *fmt;
> +
> +	fmt = imx8mq_mipi_csi_get_format(state, sd_state, sdformat->which,
> +					 sdformat->pad);
> +
> +	mutex_lock(&state->lock);
> +
> +	sdformat->format = *fmt;
> +
> +	mutex_unlock(&state->lock);
> +
> +	return 0;
> +}
> +
> +static int imx8mq_mipi_csi_enum_mbus_code(struct v4l2_subdev *sd,
> +					  struct v4l2_subdev_state *sd_state,
> +					  struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +
> +	/*
> +	 * We can't transcode in any way, the source format is identical
> +	 * to the sink format.
> +	 */
> +	if (code->pad == MIPI_CSI2_PAD_SOURCE) {
> +		struct v4l2_mbus_framefmt *fmt;
> +
> +		if (code->index > 0)
> +			return -EINVAL;
> +
> +		fmt = imx8mq_mipi_csi_get_format(state, sd_state, code->which,
> +						 code->pad);
> +		code->code = fmt->code;
> +		return 0;
> +	}
> +
> +	if (code->pad != MIPI_CSI2_PAD_SINK)
> +		return -EINVAL;
> +
> +	if (code->index >= ARRAY_SIZE(imx8mq_mipi_csi_formats))
> +		return -EINVAL;
> +
> +	code->code = imx8mq_mipi_csi_formats[code->index].code;
> +
> +	return 0;
> +}
> +
> +static int imx8mq_mipi_csi_set_fmt(struct v4l2_subdev *sd,
> +				   struct v4l2_subdev_state *sd_state,
> +				   struct v4l2_subdev_format *sdformat)
> +{
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +	struct csi2_pix_format const *csi2_fmt;
> +	struct v4l2_mbus_framefmt *fmt;
> +
> +	/*
> +	 * The device can't transcode in any way, the source format can't be
> +	 * modified.
> +	 */
> +	if (sdformat->pad == MIPI_CSI2_PAD_SOURCE)
> +		return imx8mq_mipi_csi_get_fmt(sd, sd_state, sdformat);
> +
> +	if (sdformat->pad != MIPI_CSI2_PAD_SINK)
> +		return -EINVAL;
> +
> +	csi2_fmt = find_csi2_format(sdformat->format.code);
> +	if (!csi2_fmt)
> +		csi2_fmt = &imx8mq_mipi_csi_formats[0];
> +
> +	fmt = imx8mq_mipi_csi_get_format(state, sd_state, sdformat->which,
> +					 sdformat->pad);
> +
> +	mutex_lock(&state->lock);
> +
> +	fmt->code = csi2_fmt->code;
> +	fmt->width = sdformat->format.width;
> +	fmt->height = sdformat->format.height;
> +
> +	sdformat->format = *fmt;
> +
> +	/* Propagate the format from sink to source. */
> +	fmt = imx8mq_mipi_csi_get_format(state, sd_state, sdformat->which,
> +					 MIPI_CSI2_PAD_SOURCE);
> +	*fmt = sdformat->format;
> +
> +	/* Store the CSI2 format descriptor for active formats. */
> +	if (sdformat->which == V4L2_SUBDEV_FORMAT_ACTIVE)
> +		state->csi2_fmt = csi2_fmt;
> +
> +	mutex_unlock(&state->lock);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_subdev_video_ops imx8mq_mipi_csi_video_ops = {
> +	.s_stream	= imx8mq_mipi_csi_s_stream,
> +};
> +
> +static const struct v4l2_subdev_pad_ops imx8mq_mipi_csi_pad_ops = {
> +	.init_cfg		= imx8mq_mipi_csi_init_cfg,
> +	.enum_mbus_code		= imx8mq_mipi_csi_enum_mbus_code,
> +	.get_fmt		= imx8mq_mipi_csi_get_fmt,
> +	.set_fmt		= imx8mq_mipi_csi_set_fmt,
> +};
> +
> +static const struct v4l2_subdev_ops imx8mq_mipi_csi_subdev_ops = {
> +	.video	= &imx8mq_mipi_csi_video_ops,
> +	.pad	= &imx8mq_mipi_csi_pad_ops,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Media entity operations
> + */
> +
> +static const struct media_entity_operations imx8mq_mipi_csi_entity_ops = {
> +	.link_validate	= v4l2_subdev_link_validate,
> +	.get_fwnode_pad = v4l2_subdev_get_fwnode_pad_1_to_1,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Async subdev notifier
> + */
> +
> +static struct csi_state *
> +mipi_notifier_to_csi2_state(struct v4l2_async_notifier *n)
> +{
> +	return container_of(n, struct csi_state, notifier);
> +}
> +
> +static int imx8mq_mipi_csi_notify_bound(struct v4l2_async_notifier *notifier,
> +					struct v4l2_subdev *sd,
> +					struct v4l2_async_subdev *asd)
> +{
> +	struct csi_state *state = mipi_notifier_to_csi2_state(notifier);
> +	struct media_pad *sink = &state->sd.entity.pads[MIPI_CSI2_PAD_SINK];
> +
> +	state->src_sd = sd;
> +
> +	return v4l2_create_fwnode_links_to_pad(sd, sink, MEDIA_LNK_FL_ENABLED |
> +					       MEDIA_LNK_FL_IMMUTABLE);
> +}
> +
> +static const struct v4l2_async_notifier_operations imx8mq_mipi_csi_notify_ops = {
> +	.bound = imx8mq_mipi_csi_notify_bound,
> +};
> +
> +static int imx8mq_mipi_csi_async_register(struct csi_state *state)
> +{
> +	struct v4l2_fwnode_endpoint vep = {
> +		.bus_type = V4L2_MBUS_CSI2_DPHY,
> +	};
> +	struct v4l2_async_subdev *asd;
> +	struct fwnode_handle *ep;
> +	unsigned int i;
> +	int ret;
> +
> +	v4l2_async_notifier_init(&state->notifier);
> +
> +	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(state->dev), 0, 0,
> +					     FWNODE_GRAPH_ENDPOINT_NEXT);
> +	if (!ep)
> +		return -ENOTCONN;
> +
> +	ret = v4l2_fwnode_endpoint_parse(ep, &vep);
> +	if (ret)
> +		goto err_parse;
> +
> +	for (i = 0; i < vep.bus.mipi_csi2.num_data_lanes; ++i) {
> +		if (vep.bus.mipi_csi2.data_lanes[i] != i + 1) {
> +			dev_err(state->dev,
> +				"data lanes reordering is not supported");
> +			ret = -EINVAL;
> +			goto err_parse;
> +		}
> +	}
> +
> +	state->bus = vep.bus.mipi_csi2;
> +
> +	dev_dbg(state->dev, "data lanes: %d flags: 0x%08x\n",
> +		state->bus.num_data_lanes,
> +		state->bus.flags);
> +
> +	asd = v4l2_async_notifier_add_fwnode_remote_subdev(&state->notifier,
> +							   ep, struct v4l2_async_subdev);
> +	if (IS_ERR(asd)) {
> +		ret = PTR_ERR(asd);
> +		goto err_parse;
> +	}
> +
> +	fwnode_handle_put(ep);
> +
> +	state->notifier.ops = &imx8mq_mipi_csi_notify_ops;
> +
> +	ret = v4l2_async_subdev_notifier_register(&state->sd, &state->notifier);
> +	if (ret)
> +		return ret;
> +
> +	return v4l2_async_register_subdev(&state->sd);
> +
> +err_parse:
> +	fwnode_handle_put(ep);
> +
> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Suspend/resume
> + */
> +
> +static int imx8mq_mipi_csi_pm_suspend(struct device *dev, bool runtime)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +	int ret = 0;
> +
> +	mutex_lock(&state->lock);
> +
> +	if (state->state & ST_POWERED) {
> +		imx8mq_mipi_csi_stop_stream(state);
> +		imx8mq_mipi_csi_clk_disable(state);
> +		state->state &= ~ST_POWERED;
> +		if (!runtime)
> +			state->state |= ST_SUSPENDED;
> +	}
> +
> +	mutex_unlock(&state->lock);
> +
> +	ret = icc_set_bw(state->icc_path, 0, 0);
> +	if (ret)
> +		dev_err(dev, "icc_set_bw failed with %d\n", ret);
> +
> +	return ret ? -EAGAIN : 0;
> +}
> +
> +static int imx8mq_mipi_csi_pm_resume(struct device *dev, bool runtime)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +	int ret = 0;
> +
> +	ret = icc_set_bw(state->icc_path, 0, state->icc_path_bw);
> +	if (ret) {
> +		dev_err(dev, "icc_set_bw failed with %d\n", ret);
> +		return ret;
> +	}
> +
> +	mutex_lock(&state->lock);
> +
> +	if (!runtime && !(state->state & ST_SUSPENDED))
> +		goto unlock;
> +
> +	if (!(state->state & ST_POWERED)) {
> +		state->state |= ST_POWERED;
> +		ret = imx8mq_mipi_csi_clk_enable(state);
> +	}
> +	if (state->state & ST_STREAMING) {
> +		ret = imx8mq_mipi_csi_start_stream(state);
> +		if (ret)
> +			goto unlock;
> +	}
> +
> +	state->state &= ~ST_SUSPENDED;
> +
> +unlock:
> +	mutex_unlock(&state->lock);
> +
> +	return ret ? -EAGAIN : 0;
> +}
> +
> +static int __maybe_unused imx8mq_mipi_csi_suspend(struct device *dev)
> +{
> +	return imx8mq_mipi_csi_pm_suspend(dev, false);
> +}
> +
> +static int __maybe_unused imx8mq_mipi_csi_resume(struct device *dev)
> +{
> +	return imx8mq_mipi_csi_pm_resume(dev, false);
> +}
> +
> +static int __maybe_unused imx8mq_mipi_csi_runtime_suspend(struct device *dev)
> +{
> +	return imx8mq_mipi_csi_pm_suspend(dev, true);
> +}
> +
> +static int __maybe_unused imx8mq_mipi_csi_runtime_resume(struct device *dev)
> +{
> +	return imx8mq_mipi_csi_pm_resume(dev, true);
> +}
> +
> +static const struct dev_pm_ops imx8mq_mipi_csi_pm_ops = {
> +	SET_RUNTIME_PM_OPS(imx8mq_mipi_csi_runtime_suspend,
> +			   imx8mq_mipi_csi_runtime_resume,
> +			   NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(imx8mq_mipi_csi_suspend, imx8mq_mipi_csi_resume)
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Probe/remove & platform driver
> + */
> +
> +static int imx8mq_mipi_csi_subdev_init(struct csi_state *state)
> +{
> +	struct v4l2_subdev *sd = &state->sd;
> +
> +	v4l2_subdev_init(sd, &imx8mq_mipi_csi_subdev_ops);
> +	sd->owner = THIS_MODULE;
> +	snprintf(sd->name, sizeof(sd->name), "%s %s",
> +		 MIPI_CSI2_SUBDEV_NAME, dev_name(state->dev));
> +
> +	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> +	sd->entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
> +	sd->entity.ops = &imx8mq_mipi_csi_entity_ops;
> +
> +	sd->dev = state->dev;
> +
> +	state->csi2_fmt = &imx8mq_mipi_csi_formats[0];
> +	imx8mq_mipi_csi_init_cfg(sd, NULL);
> +
> +	state->pads[MIPI_CSI2_PAD_SINK].flags = MEDIA_PAD_FL_SINK
> +					 | MEDIA_PAD_FL_MUST_CONNECT;
> +	state->pads[MIPI_CSI2_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE
> +					   | MEDIA_PAD_FL_MUST_CONNECT;
> +	return media_entity_pads_init(&sd->entity, MIPI_CSI2_PADS_NUM,
> +				      state->pads);
> +}
> +
> +static void imx8mq_mipi_csi_release_icc(struct platform_device *pdev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(&pdev->dev);
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +
> +	icc_put(state->icc_path);
> +}
> +
> +static int imx8mq_mipi_csi_init_icc(struct platform_device *pdev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(&pdev->dev);
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +
> +	/* Optional interconnect request */
> +	state->icc_path = of_icc_get(&pdev->dev, "dram");
> +	if (IS_ERR_OR_NULL(state->icc_path))
> +		return PTR_ERR_OR_ZERO(state->icc_path);
> +
> +	state->icc_path_bw = MBps_to_icc(700);
> +
> +	return 0;
> +}
> +
> +static int imx8mq_mipi_csi_parse_dt(struct csi_state *state)
> +{
> +	struct device *dev = state->dev;
> +	struct device_node *np = state->dev->of_node;
> +	struct device_node *node;
> +	phandle ph;
> +	u32 out_val[2];
> +	int ret = 0;
> +
> +	state->rst = devm_reset_control_array_get_exclusive(dev);
> +	if (IS_ERR(state->rst)) {
> +		dev_err(dev, "Failed to get reset: %pe\n", state->rst);
> +		return PTR_ERR(state->rst);
> +	}
> +
> +	ret = of_property_read_u32_array(np, "fsl,mipi-phy-gpr", out_val,
> +					 ARRAY_SIZE(out_val));
> +	if (ret) {
> +		dev_err(dev, "no fsl,mipi-phy-gpr property found: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ph = *out_val;
> +
> +	node = of_find_node_by_phandle(ph);
> +	if (!node) {
> +		dev_err(dev, "Error finding node by phandle\n");
> +		return -ENODEV;
> +	}
> +	state->phy_gpr = syscon_node_to_regmap(node);
> +	of_node_put(node);
> +	if (IS_ERR(state->phy_gpr)) {
> +		dev_err(dev, "failed to get gpr regmap: %pe\n", state->phy_gpr);
> +		return PTR_ERR(state->phy_gpr);
> +	}
> +
> +	state->phy_gpr_reg = out_val[1];
> +	dev_dbg(dev, "phy gpr register set to 0x%x\n", state->phy_gpr_reg);
> +
> +	return ret;
> +}
> +
> +static int imx8mq_mipi_csi_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct csi_state *state;
> +	int ret;
> +
> +	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
> +	if (!state)
> +		return -ENOMEM;
> +
> +	state->dev = dev;
> +
> +	ret = imx8mq_mipi_csi_parse_dt(state);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to parse device tree: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Acquire resources. */
> +	state->regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(state->regs))
> +		return PTR_ERR(state->regs);
> +
> +	ret = imx8mq_mipi_csi_clk_get(state);
> +	if (ret < 0)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, &state->sd);
> +
> +	mutex_init(&state->lock);
> +
> +	ret = imx8mq_mipi_csi_subdev_init(state);
> +	if (ret < 0)
> +		goto mutex;
> +
> +	ret = imx8mq_mipi_csi_init_icc(pdev);
> +	if (ret)
> +		goto mutex;
> +
> +	/* Enable runtime PM. */
> +	pm_runtime_enable(dev);
> +	if (!pm_runtime_enabled(dev)) {
> +		ret = imx8mq_mipi_csi_pm_resume(dev, true);
> +		if (ret < 0)
> +			goto icc;
> +	}
> +
> +	ret = imx8mq_mipi_csi_async_register(state);
> +	if (ret < 0)
> +		goto cleanup;
> +
> +	return 0;
> +
> +cleanup:
> +	pm_runtime_disable(&pdev->dev);
> +	imx8mq_mipi_csi_pm_suspend(&pdev->dev, true);
> +
> +	media_entity_cleanup(&state->sd.entity);
> +	v4l2_async_notifier_unregister(&state->notifier);
> +	v4l2_async_notifier_cleanup(&state->notifier);
> +	v4l2_async_unregister_subdev(&state->sd);
> +icc:
> +	imx8mq_mipi_csi_release_icc(pdev);
> +mutex:
> +	mutex_destroy(&state->lock);
> +
> +	return ret;
> +}
> +
> +static int imx8mq_mipi_csi_remove(struct platform_device *pdev)
> +{
> +	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
> +	struct csi_state *state = mipi_sd_to_csi2_state(sd);
> +
> +	v4l2_async_notifier_unregister(&state->notifier);
> +	v4l2_async_notifier_cleanup(&state->notifier);
> +	v4l2_async_unregister_subdev(&state->sd);
> +
> +	pm_runtime_disable(&pdev->dev);
> +	imx8mq_mipi_csi_pm_suspend(&pdev->dev, true);
> +	media_entity_cleanup(&state->sd.entity);
> +	mutex_destroy(&state->lock);
> +	pm_runtime_set_suspended(&pdev->dev);
> +	imx8mq_mipi_csi_release_icc(pdev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id imx8mq_mipi_csi_of_match[] = {
> +	{ .compatible = "fsl,imx8mq-mipi-csi2", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, imx8mq_mipi_csi_of_match);
> +
> +static struct platform_driver imx8mq_mipi_csi_driver = {
> +	.probe		= imx8mq_mipi_csi_probe,
> +	.remove		= imx8mq_mipi_csi_remove,
> +	.driver		= {
> +		.of_match_table = imx8mq_mipi_csi_of_match,
> +		.name		= MIPI_CSI2_DRIVER_NAME,
> +		.pm		= &imx8mq_mipi_csi_pm_ops,
> +	},
> +};
> +
> +module_platform_driver(imx8mq_mipi_csi_driver);
> +
> +MODULE_DESCRIPTION("i.MX8MQ MIPI CSI-2 receiver driver");
> +MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@puri.sm>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:imx8mq-mipi-csi2");

-- 
Regards,

Laurent Pinchart