drivers/media/pci/intel/ivsc/mei_csi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2023 Intel Corporation. All rights reserved.
 * Intel Visual Sensing Controller CSI Linux driver
 */

/*
 * To set ownership of CSI-2 link and to configure CSI-2 link, there
 * are specific commands, which are sent via MEI protocol. The send
 * command function uses "completion" as a synchronization mechanism.
 * The response for command is received via a mei callback which wakes
 * up the caller. There can be only one outstanding command at a time.
 */

#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/mei_cl_bus.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/units.h>
#include <linux/uuid.h>
#include <linux/workqueue.h>

#include <media/v4l2-async.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>

#define MEI_CSI_ENTITY_NAME "Intel IVSC CSI"

#define MEI_CSI_LINK_FREQ_400MHZ 400000000ULL

/* the 5s used here is based on experiment */
#define CSI_CMD_TIMEOUT (5 * HZ)
/* to setup CSI-2 link an extra delay needed and determined experimentally */
#define CSI_FW_READY_DELAY_MS 100
/* link frequency unit is 100kHz */
#define CSI_LINK_FREQ(x) ((u32)(div_u64(x, 100 * HZ_PER_KHZ)))

/*
 * identify the command id supported by firmware
 * IPC, as well as the privacy notification id
 * used when processing privacy event.
 */
enum csi_cmd_id {
	/* used to set csi ownership */
	CSI_SET_OWNER = 0,

	/* used to configure CSI-2 link */
	CSI_SET_CONF = 2,

	/* privacy notification id used when privacy state changes */
	CSI_PRIVACY_NOTIF = 6,
};

/* CSI-2 link ownership definition */
enum csi_link_owner {
	CSI_LINK_IVSC,
	CSI_LINK_HOST,
};

/* privacy status definition */
enum ivsc_privacy_status {
	CSI_PRIVACY_OFF,
	CSI_PRIVACY_ON,
	CSI_PRIVACY_MAX,
};

enum csi_pads {
	CSI_PAD_SINK,
	CSI_PAD_SOURCE,
	CSI_NUM_PADS
};

/* configuration of the CSI-2 link between host and IVSC */
struct csi_link_cfg {
	/* number of data lanes used on the CSI-2 link */
	u32 nr_of_lanes;

	/* frequency of the CSI-2 link */
	u32 link_freq;

	/* for future use */
	u32 rsvd[2];
} __packed;

/* CSI command structure */
struct csi_cmd {
	u32 cmd_id;
	union _cmd_param {
		u32 param;
		struct csi_link_cfg conf;
	} param;
} __packed;

/* CSI notification structure */
struct csi_notif {
	u32 cmd_id;
	int status;
	union _resp_cont {
		u32 cont;
		struct csi_link_cfg conf;
	} cont;
} __packed;

struct mei_csi {
	struct mei_cl_device *cldev;

	/* command response */
	struct csi_notif cmd_response;
	/* used to wait for command response from firmware */
	struct completion cmd_completion;
	/* protect command download */
	struct mutex lock;

	struct v4l2_subdev subdev;
	struct v4l2_subdev *remote;
	struct v4l2_async_notifier notifier;
	struct v4l2_ctrl_handler ctrl_handler;
	struct v4l2_ctrl *freq_ctrl;
	struct v4l2_ctrl *privacy_ctrl;
	unsigned int remote_pad;
	/* start streaming or not */
	int streaming;

	struct media_pad pads[CSI_NUM_PADS];

	/* number of data lanes used on the CSI-2 link */
	u32 nr_of_lanes;
	/* frequency of the CSI-2 link */
	u64 link_freq;

	/* privacy status */
	enum ivsc_privacy_status status;
};

static const struct v4l2_mbus_framefmt mei_csi_format_mbus_default = {
	.width = 1,
	.height = 1,
	.code = MEDIA_BUS_FMT_Y8_1X8,
	.field = V4L2_FIELD_NONE,
};

static s64 link_freq_menu_items[] = {
	MEI_CSI_LINK_FREQ_400MHZ
};

static inline struct mei_csi *notifier_to_csi(struct v4l2_async_notifier *n)
{
	return container_of(n, struct mei_csi, notifier);
}

static inline struct mei_csi *sd_to_csi(struct v4l2_subdev *sd)
{
	return container_of(sd, struct mei_csi, subdev);
}

static inline struct mei_csi *ctrl_to_csi(struct v4l2_ctrl *ctrl)
{
	return container_of(ctrl->handler, struct mei_csi, ctrl_handler);
}

/* send a command to firmware and mutex must be held by caller */
static int mei_csi_send(struct mei_csi *csi, u8 *buf, size_t len)
{
	struct csi_cmd *cmd = (struct csi_cmd *)buf;
	int ret;

	reinit_completion(&csi->cmd_completion);

	ret = mei_cldev_send(csi->cldev, buf, len);
	if (ret < 0)
		goto out;

	ret = wait_for_completion_killable_timeout(&csi->cmd_completion,
						   CSI_CMD_TIMEOUT);
	if (ret < 0) {
		goto out;
	} else if (!ret) {
		ret = -ETIMEDOUT;
		goto out;
	}

	/* command response status */
	ret = csi->cmd_response.status;
	if (ret) {
		ret = -EINVAL;
		goto out;
	}

	if (csi->cmd_response.cmd_id != cmd->cmd_id)
		ret = -EINVAL;

out:
	return ret;
}

/* set CSI-2 link ownership */
static int csi_set_link_owner(struct mei_csi *csi, enum csi_link_owner owner)
{
	struct csi_cmd cmd = { 0 };
	size_t cmd_size;
	int ret;

	cmd.cmd_id = CSI_SET_OWNER;
	cmd.param.param = owner;
	cmd_size = sizeof(cmd.cmd_id) + sizeof(cmd.param.param);

	mutex_lock(&csi->lock);

	ret = mei_csi_send(csi, (u8 *)&cmd, cmd_size);

	mutex_unlock(&csi->lock);

	return ret;
}

/* configure CSI-2 link between host and IVSC */
static int csi_set_link_cfg(struct mei_csi *csi)
{
	struct csi_cmd cmd = { 0 };
	size_t cmd_size;
	int ret;

	cmd.cmd_id = CSI_SET_CONF;
	cmd.param.conf.nr_of_lanes = csi->nr_of_lanes;
	cmd.param.conf.link_freq = CSI_LINK_FREQ(csi->link_freq);
	cmd_size = sizeof(cmd.cmd_id) + sizeof(cmd.param.conf);

	mutex_lock(&csi->lock);

	ret = mei_csi_send(csi, (u8 *)&cmd, cmd_size);
	/*
	 * wait configuration ready if download success. placing
	 * delay under mutex is to make sure current command flow
	 * completed before starting a possible new one.
	 */
	if (!ret)
		msleep(CSI_FW_READY_DELAY_MS);

	mutex_unlock(&csi->lock);

	return ret;
}

/* callback for receive */
static void mei_csi_rx(struct mei_cl_device *cldev)
{
	struct mei_csi *csi = mei_cldev_get_drvdata(cldev);
	struct csi_notif notif = { 0 };
	int ret;

	ret = mei_cldev_recv(cldev, (u8 *)&notif, sizeof(notif));
	if (ret < 0) {
		dev_err(&cldev->dev, "recv error: %d\n", ret);
		return;
	}

	switch (notif.cmd_id) {
	case CSI_PRIVACY_NOTIF:
		if (notif.cont.cont < CSI_PRIVACY_MAX) {
			csi->status = notif.cont.cont;
			v4l2_ctrl_s_ctrl(csi->privacy_ctrl, csi->status);
		}
		break;
	case CSI_SET_OWNER:
	case CSI_SET_CONF:
		memcpy(&csi->cmd_response, &notif, ret);

		complete(&csi->cmd_completion);
		break;
	default:
		break;
	}
}

static int mei_csi_set_stream(struct v4l2_subdev *sd, int enable)
{
	struct mei_csi *csi = sd_to_csi(sd);
	s64 freq;
	int ret;

	if (enable && csi->streaming == 0) {
		freq = v4l2_get_link_freq(csi->remote->ctrl_handler, 0, 0);
		if (freq < 0) {
			dev_err(&csi->cldev->dev,
				"error %lld, invalid link_freq\n", freq);
			ret = freq;
			goto err;
		}
		csi->link_freq = freq;

		/* switch CSI-2 link to host */
		ret = csi_set_link_owner(csi, CSI_LINK_HOST);
		if (ret < 0)
			goto err;

		/* configure CSI-2 link */
		ret = csi_set_link_cfg(csi);
		if (ret < 0)
			goto err_switch;

		ret = v4l2_subdev_call(csi->remote, video, s_stream, 1);
		if (ret)
			goto err_switch;
	} else if (!enable && csi->streaming == 1) {
		v4l2_subdev_call(csi->remote, video, s_stream, 0);

		/* switch CSI-2 link to IVSC */
		ret = csi_set_link_owner(csi, CSI_LINK_IVSC);
		if (ret < 0)
			dev_warn(&csi->cldev->dev,
				 "failed to switch CSI2 link: %d\n", ret);
	}

	csi->streaming = enable;

	return 0;

err_switch:
	csi_set_link_owner(csi, CSI_LINK_IVSC);

err:
	return ret;
}

static int mei_csi_init_state(struct v4l2_subdev *sd,
			      struct v4l2_subdev_state *sd_state)
{
	struct v4l2_mbus_framefmt *mbusformat;
	unsigned int i;

	for (i = 0; i < sd->entity.num_pads; i++) {
		mbusformat = v4l2_subdev_state_get_format(sd_state, i);
		*mbusformat = mei_csi_format_mbus_default;
	}

	return 0;
}

static int mei_csi_set_fmt(struct v4l2_subdev *sd,
			   struct v4l2_subdev_state *sd_state,
			   struct v4l2_subdev_format *format)
{
	struct v4l2_mbus_framefmt *source_fmt;
	struct v4l2_mbus_framefmt *sink_fmt;

	sink_fmt = v4l2_subdev_state_get_format(sd_state, CSI_PAD_SINK);
	source_fmt = v4l2_subdev_state_get_format(sd_state, CSI_PAD_SOURCE);

	if (format->pad) {
		*source_fmt = *sink_fmt;

		return 0;
	}

	v4l_bound_align_image(&format->format.width, 1, 65536, 0,
			      &format->format.height, 1, 65536, 0, 0);

	switch (format->format.code) {
	case MEDIA_BUS_FMT_RGB444_1X12:
	case MEDIA_BUS_FMT_RGB444_2X8_PADHI_BE:
	case MEDIA_BUS_FMT_RGB444_2X8_PADHI_LE:
	case MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE:
	case MEDIA_BUS_FMT_RGB555_2X8_PADHI_LE:
	case MEDIA_BUS_FMT_RGB565_1X16:
	case MEDIA_BUS_FMT_BGR565_2X8_BE:
	case MEDIA_BUS_FMT_BGR565_2X8_LE:
	case MEDIA_BUS_FMT_RGB565_2X8_BE:
	case MEDIA_BUS_FMT_RGB565_2X8_LE:
	case MEDIA_BUS_FMT_RGB666_1X18:
	case MEDIA_BUS_FMT_RBG888_1X24:
	case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
	case MEDIA_BUS_FMT_BGR888_1X24:
	case MEDIA_BUS_FMT_GBR888_1X24:
	case MEDIA_BUS_FMT_RGB888_1X24:
	case MEDIA_BUS_FMT_RGB888_2X12_BE:
	case MEDIA_BUS_FMT_RGB888_2X12_LE:
	case MEDIA_BUS_FMT_ARGB8888_1X32:
	case MEDIA_BUS_FMT_RGB888_1X32_PADHI:
	case MEDIA_BUS_FMT_RGB101010_1X30:
	case MEDIA_BUS_FMT_RGB121212_1X36:
	case MEDIA_BUS_FMT_RGB161616_1X48:
	case MEDIA_BUS_FMT_Y8_1X8:
	case MEDIA_BUS_FMT_UV8_1X8:
	case MEDIA_BUS_FMT_UYVY8_1_5X8:
	case MEDIA_BUS_FMT_VYUY8_1_5X8:
	case MEDIA_BUS_FMT_YUYV8_1_5X8:
	case MEDIA_BUS_FMT_YVYU8_1_5X8:
	case MEDIA_BUS_FMT_UYVY8_2X8:
	case MEDIA_BUS_FMT_VYUY8_2X8:
	case MEDIA_BUS_FMT_YUYV8_2X8:
	case MEDIA_BUS_FMT_YVYU8_2X8:
	case MEDIA_BUS_FMT_Y10_1X10:
	case MEDIA_BUS_FMT_UYVY10_2X10:
	case MEDIA_BUS_FMT_VYUY10_2X10:
	case MEDIA_BUS_FMT_YUYV10_2X10:
	case MEDIA_BUS_FMT_YVYU10_2X10:
	case MEDIA_BUS_FMT_Y12_1X12:
	case MEDIA_BUS_FMT_UYVY12_2X12:
	case MEDIA_BUS_FMT_VYUY12_2X12:
	case MEDIA_BUS_FMT_YUYV12_2X12:
	case MEDIA_BUS_FMT_YVYU12_2X12:
	case MEDIA_BUS_FMT_UYVY8_1X16:
	case MEDIA_BUS_FMT_VYUY8_1X16:
	case MEDIA_BUS_FMT_YUYV8_1X16:
	case MEDIA_BUS_FMT_YVYU8_1X16:
	case MEDIA_BUS_FMT_YDYUYDYV8_1X16:
	case MEDIA_BUS_FMT_UYVY10_1X20:
	case MEDIA_BUS_FMT_VYUY10_1X20:
	case MEDIA_BUS_FMT_YUYV10_1X20:
	case MEDIA_BUS_FMT_YVYU10_1X20:
	case MEDIA_BUS_FMT_VUY8_1X24:
	case MEDIA_BUS_FMT_YUV8_1X24:
	case MEDIA_BUS_FMT_UYYVYY8_0_5X24:
	case MEDIA_BUS_FMT_UYVY12_1X24:
	case MEDIA_BUS_FMT_VYUY12_1X24:
	case MEDIA_BUS_FMT_YUYV12_1X24:
	case MEDIA_BUS_FMT_YVYU12_1X24:
	case MEDIA_BUS_FMT_YUV10_1X30:
	case MEDIA_BUS_FMT_UYYVYY10_0_5X30:
	case MEDIA_BUS_FMT_AYUV8_1X32:
	case MEDIA_BUS_FMT_UYYVYY12_0_5X36:
	case MEDIA_BUS_FMT_YUV12_1X36:
	case MEDIA_BUS_FMT_YUV16_1X48:
	case MEDIA_BUS_FMT_UYYVYY16_0_5X48:
	case MEDIA_BUS_FMT_JPEG_1X8:
	case MEDIA_BUS_FMT_AHSV8888_1X32:
	case MEDIA_BUS_FMT_SBGGR8_1X8:
	case MEDIA_BUS_FMT_SGBRG8_1X8:
	case MEDIA_BUS_FMT_SGRBG8_1X8:
	case MEDIA_BUS_FMT_SRGGB8_1X8:
	case MEDIA_BUS_FMT_SBGGR10_1X10:
	case MEDIA_BUS_FMT_SGBRG10_1X10:
	case MEDIA_BUS_FMT_SGRBG10_1X10:
	case MEDIA_BUS_FMT_SRGGB10_1X10:
	case MEDIA_BUS_FMT_SBGGR12_1X12:
	case MEDIA_BUS_FMT_SGBRG12_1X12:
	case MEDIA_BUS_FMT_SGRBG12_1X12:
	case MEDIA_BUS_FMT_SRGGB12_1X12:
	case MEDIA_BUS_FMT_SBGGR14_1X14:
	case MEDIA_BUS_FMT_SGBRG14_1X14:
	case MEDIA_BUS_FMT_SGRBG14_1X14:
	case MEDIA_BUS_FMT_SRGGB14_1X14:
	case MEDIA_BUS_FMT_SBGGR16_1X16:
	case MEDIA_BUS_FMT_SGBRG16_1X16:
	case MEDIA_BUS_FMT_SGRBG16_1X16:
	case MEDIA_BUS_FMT_SRGGB16_1X16:
		break;
	default:
		format->format.code = MEDIA_BUS_FMT_Y8_1X8;
		break;
	}

	if (format->format.field == V4L2_FIELD_ANY)
		format->format.field = V4L2_FIELD_NONE;

	*sink_fmt = format->format;
	*source_fmt = *sink_fmt;

	return 0;
}

static int mei_csi_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
	struct mei_csi *csi = ctrl_to_csi(ctrl);
	s64 freq;

	if (ctrl->id == V4L2_CID_LINK_FREQ) {
		if (!csi->remote)
			return -EINVAL;

		freq = v4l2_get_link_freq(csi->remote->ctrl_handler, 0, 0);
		if (freq < 0) {
			dev_err(&csi->cldev->dev,
				"error %lld, invalid link_freq\n", freq);
			return -EINVAL;
		}

		link_freq_menu_items[0] = freq;
		ctrl->val = 0;

		return 0;
	}

	return -EINVAL;
}

static const struct v4l2_ctrl_ops mei_csi_ctrl_ops = {
	.g_volatile_ctrl = mei_csi_g_volatile_ctrl,
};

static const struct v4l2_subdev_video_ops mei_csi_video_ops = {
	.s_stream = mei_csi_set_stream,
};

static const struct v4l2_subdev_pad_ops mei_csi_pad_ops = {
	.get_fmt = v4l2_subdev_get_fmt,
	.set_fmt = mei_csi_set_fmt,
};

static const struct v4l2_subdev_ops mei_csi_subdev_ops = {
	.video = &mei_csi_video_ops,
	.pad = &mei_csi_pad_ops,
};

static const struct v4l2_subdev_internal_ops mei_csi_internal_ops = {
	.init_state = mei_csi_init_state,
};

static const struct media_entity_operations mei_csi_entity_ops = {
	.link_validate = v4l2_subdev_link_validate,
};

static int mei_csi_notify_bound(struct v4l2_async_notifier *notifier,
				struct v4l2_subdev *subdev,
				struct v4l2_async_connection *asd)
{
	struct mei_csi *csi = notifier_to_csi(notifier);
	int pad;

	pad = media_entity_get_fwnode_pad(&subdev->entity, asd->match.fwnode,
					  MEDIA_PAD_FL_SOURCE);
	if (pad < 0)
		return pad;

	csi->remote = subdev;
	csi->remote_pad = pad;

	return media_create_pad_link(&subdev->entity, pad,
				     &csi->subdev.entity, CSI_PAD_SINK,
				     MEDIA_LNK_FL_ENABLED |
				     MEDIA_LNK_FL_IMMUTABLE);
}

static void mei_csi_notify_unbind(struct v4l2_async_notifier *notifier,
				  struct v4l2_subdev *subdev,
				  struct v4l2_async_connection *asd)
{
	struct mei_csi *csi = notifier_to_csi(notifier);

	csi->remote = NULL;
}

static const struct v4l2_async_notifier_operations mei_csi_notify_ops = {
	.bound = mei_csi_notify_bound,
	.unbind = mei_csi_notify_unbind,
};

static int mei_csi_init_controls(struct mei_csi *csi)
{
	u32 max;
	int ret;

	ret = v4l2_ctrl_handler_init(&csi->ctrl_handler, 2);
	if (ret)
		return ret;

	csi->ctrl_handler.lock = &csi->lock;

	max = ARRAY_SIZE(link_freq_menu_items) - 1;
	csi->freq_ctrl = v4l2_ctrl_new_int_menu(&csi->ctrl_handler,
						&mei_csi_ctrl_ops,
						V4L2_CID_LINK_FREQ,
						max,
						0,
						link_freq_menu_items);
	if (csi->freq_ctrl)
		csi->freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY |
					 V4L2_CTRL_FLAG_VOLATILE;

	csi->privacy_ctrl = v4l2_ctrl_new_std(&csi->ctrl_handler, NULL,
					      V4L2_CID_PRIVACY, 0, 1, 1, 0);
	if (csi->privacy_ctrl)
		csi->privacy_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;

	if (csi->ctrl_handler.error)
		return csi->ctrl_handler.error;

	csi->subdev.ctrl_handler = &csi->ctrl_handler;

	return 0;
}

static int mei_csi_parse_firmware(struct mei_csi *csi)
{
	struct v4l2_fwnode_endpoint v4l2_ep = {
		.bus_type = V4L2_MBUS_CSI2_DPHY,
	};
	struct device *dev = &csi->cldev->dev;
	struct v4l2_async_connection *asd;
	struct fwnode_handle *sink_ep, *source_ep;
	int ret;

	sink_ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0, 0);
	if (!sink_ep) {
		dev_err(dev, "can't obtain sink endpoint\n");
		return -EINVAL;
	}

	v4l2_async_subdev_nf_init(&csi->notifier, &csi->subdev);
	csi->notifier.ops = &mei_csi_notify_ops;

	ret = v4l2_fwnode_endpoint_parse(sink_ep, &v4l2_ep);
	if (ret) {
		dev_err(dev, "could not parse v4l2 sink endpoint\n");
		goto out_nf_cleanup;
	}

	csi->nr_of_lanes = v4l2_ep.bus.mipi_csi2.num_data_lanes;

	source_ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 1, 0, 0);
	if (!source_ep) {
		ret = -ENOTCONN;
		dev_err(dev, "can't obtain source endpoint\n");
		goto out_nf_cleanup;
	}

	ret = v4l2_fwnode_endpoint_parse(source_ep, &v4l2_ep);
	fwnode_handle_put(source_ep);
	if (ret) {
		dev_err(dev, "could not parse v4l2 source endpoint\n");
		goto out_nf_cleanup;
	}

	if (csi->nr_of_lanes != v4l2_ep.bus.mipi_csi2.num_data_lanes) {
		ret = -EINVAL;
		dev_err(dev,
			"the number of lanes does not match (%u vs. %u)\n",
			csi->nr_of_lanes, v4l2_ep.bus.mipi_csi2.num_data_lanes);
		goto out_nf_cleanup;
	}

	asd = v4l2_async_nf_add_fwnode_remote(&csi->notifier, sink_ep,
					      struct v4l2_async_connection);
	if (IS_ERR(asd)) {
		ret = PTR_ERR(asd);
		goto out_nf_cleanup;
	}

	ret = v4l2_async_nf_register(&csi->notifier);
	if (ret)
		goto out_nf_cleanup;

	fwnode_handle_put(sink_ep);

	return 0;

out_nf_cleanup:
	v4l2_async_nf_cleanup(&csi->notifier);
	fwnode_handle_put(sink_ep);

	return ret;
}

static int mei_csi_probe(struct mei_cl_device *cldev,
			 const struct mei_cl_device_id *id)
{
	struct device *dev = &cldev->dev;
	struct mei_csi *csi;
	int ret;

	if (!dev_fwnode(dev))
		return -EPROBE_DEFER;

	csi = devm_kzalloc(dev, sizeof(struct mei_csi), GFP_KERNEL);
	if (!csi)
		return -ENOMEM;

	csi->cldev = cldev;
	mutex_init(&csi->lock);
	init_completion(&csi->cmd_completion);

	mei_cldev_set_drvdata(cldev, csi);

	ret = mei_cldev_enable(cldev);
	if (ret < 0) {
		dev_err(dev, "mei_cldev_enable failed: %d\n", ret);
		goto destroy_mutex;
	}

	ret = mei_cldev_register_rx_cb(cldev, mei_csi_rx);
	if (ret) {
		dev_err(dev, "event cb registration failed: %d\n", ret);
		goto err_disable;
	}

	ret = mei_csi_parse_firmware(csi);
	if (ret)
		goto err_disable;

	csi->subdev.dev = &cldev->dev;
	csi->subdev.state_lock = &csi->lock;
	v4l2_subdev_init(&csi->subdev, &mei_csi_subdev_ops);
	csi->subdev.internal_ops = &mei_csi_internal_ops;
	v4l2_set_subdevdata(&csi->subdev, csi);
	csi->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
			    V4L2_SUBDEV_FL_HAS_EVENTS;
	csi->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
	csi->subdev.entity.ops = &mei_csi_entity_ops;

	snprintf(csi->subdev.name, sizeof(csi->subdev.name),
		 MEI_CSI_ENTITY_NAME);

	ret = mei_csi_init_controls(csi);
	if (ret)
		goto err_ctrl_handler;

	csi->pads[CSI_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
	csi->pads[CSI_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
	ret = media_entity_pads_init(&csi->subdev.entity, CSI_NUM_PADS,
				     csi->pads);
	if (ret)
		goto err_ctrl_handler;

	ret = v4l2_subdev_init_finalize(&csi->subdev);
	if (ret < 0)
		goto err_entity;

	ret = v4l2_async_register_subdev(&csi->subdev);
	if (ret < 0)
		goto err_subdev;

	pm_runtime_enable(&cldev->dev);

	return 0;

err_subdev:
	v4l2_subdev_cleanup(&csi->subdev);

err_entity:
	media_entity_cleanup(&csi->subdev.entity);

err_ctrl_handler:
	v4l2_ctrl_handler_free(&csi->ctrl_handler);
	v4l2_async_nf_unregister(&csi->notifier);
	v4l2_async_nf_cleanup(&csi->notifier);

err_disable:
	mei_cldev_disable(cldev);

destroy_mutex:
	mutex_destroy(&csi->lock);

	return ret;
}

static void mei_csi_remove(struct mei_cl_device *cldev)
{
	struct mei_csi *csi = mei_cldev_get_drvdata(cldev);

	v4l2_async_nf_unregister(&csi->notifier);
	v4l2_async_nf_cleanup(&csi->notifier);
	v4l2_ctrl_handler_free(&csi->ctrl_handler);
	v4l2_async_unregister_subdev(&csi->subdev);
	v4l2_subdev_cleanup(&csi->subdev);
	media_entity_cleanup(&csi->subdev.entity);

	pm_runtime_disable(&cldev->dev);

	mutex_destroy(&csi->lock);
}

#define MEI_CSI_UUID UUID_LE(0x92335FCF, 0x3203, 0x4472, \
			     0xAF, 0x93, 0x7b, 0x44, 0x53, 0xAC, 0x29, 0xDA)

static const struct mei_cl_device_id mei_csi_tbl[] = {
	{ .uuid = MEI_CSI_UUID, .version = MEI_CL_VERSION_ANY },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(mei, mei_csi_tbl);

static struct mei_cl_driver mei_csi_driver = {
	.id_table = mei_csi_tbl,
	.name = KBUILD_MODNAME,

	.probe = mei_csi_probe,
	.remove = mei_csi_remove,
};

module_mei_cl_driver(mei_csi_driver);

MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
MODULE_DESCRIPTION("Device driver for IVSC CSI");
MODULE_LICENSE("GPL");