xref: /openbmc/linux/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c (revision 722d4f06e560ae8eee84fbd63035356592a37dd1)

// SPDX-License-Identifier: GPL-2.0+

/*
 * Copyright 2020 NXP
 */

#include <linux/clk.h>
#include <linux/media-bus-format.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>

#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>

#include "imx-ldb-helper.h"

#define  LDB_CH_SEL		BIT(28)

#define SS_CTRL			0x20
#define  CH_HSYNC_M(id)		BIT(0 + ((id) * 2))
#define  CH_VSYNC_M(id)		BIT(1 + ((id) * 2))
#define  CH_PHSYNC(id)		BIT(0 + ((id) * 2))
#define  CH_PVSYNC(id)		BIT(1 + ((id) * 2))

#define DRIVER_NAME		"imx8qxp-ldb"

struct imx8qxp_ldb_channel {
	struct ldb_channel base;
	struct phy *phy;
	unsigned int di_id;
};

struct imx8qxp_ldb {
	struct ldb base;
	struct device *dev;
	struct imx8qxp_ldb_channel channel[MAX_LDB_CHAN_NUM];
	struct clk *clk_pixel;
	struct clk *clk_bypass;
	struct drm_bridge *companion;
	int active_chno;
};

static inline struct imx8qxp_ldb_channel *
base_to_imx8qxp_ldb_channel(struct ldb_channel *base)
{
	return container_of(base, struct imx8qxp_ldb_channel, base);
}

static inline struct imx8qxp_ldb *base_to_imx8qxp_ldb(struct ldb *base)
{
	return container_of(base, struct imx8qxp_ldb, base);
}

static void imx8qxp_ldb_set_phy_cfg(struct imx8qxp_ldb *imx8qxp_ldb,
				    unsigned long di_clk, bool is_split,
				    struct phy_configure_opts_lvds *phy_cfg)
{
	phy_cfg->bits_per_lane_and_dclk_cycle = 7;
	phy_cfg->lanes = 4;

	if (is_split) {
		phy_cfg->differential_clk_rate = di_clk / 2;
		phy_cfg->is_slave = !imx8qxp_ldb->companion;
	} else {
		phy_cfg->differential_clk_rate = di_clk;
		phy_cfg->is_slave = false;
	}
}

static int
imx8qxp_ldb_bridge_atomic_check(struct drm_bridge *bridge,
				struct drm_bridge_state *bridge_state,
				struct drm_crtc_state *crtc_state,
				struct drm_connector_state *conn_state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
					base_to_imx8qxp_ldb_channel(ldb_ch);
	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
	struct drm_bridge *companion = imx8qxp_ldb->companion;
	struct drm_display_mode *adj = &crtc_state->adjusted_mode;
	unsigned long di_clk = adj->clock * 1000;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	union phy_configure_opts opts = { };
	struct phy_configure_opts_lvds *phy_cfg = &opts.lvds;
	int ret;

	ret = ldb_bridge_atomic_check_helper(bridge, bridge_state,
					     crtc_state, conn_state);
	if (ret)
		return ret;

	imx8qxp_ldb_set_phy_cfg(imx8qxp_ldb, di_clk, is_split, phy_cfg);
	ret = phy_validate(imx8qxp_ldb_ch->phy, PHY_MODE_LVDS, 0, &opts);
	if (ret < 0) {
		DRM_DEV_DEBUG_DRIVER(imx8qxp_ldb->dev,
				     "failed to validate PHY: %d\n", ret);
		return ret;
	}

	if (is_split && companion) {
		ret = companion->funcs->atomic_check(companion,
					bridge_state, crtc_state, conn_state);
		if (ret)
			return ret;
	}

	return ret;
}

static void
imx8qxp_ldb_bridge_mode_set(struct drm_bridge *bridge,
			    const struct drm_display_mode *mode,
			    const struct drm_display_mode *adjusted_mode)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb_channel *companion_ldb_ch;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
					base_to_imx8qxp_ldb_channel(ldb_ch);
	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
	struct drm_bridge *companion = imx8qxp_ldb->companion;
	struct device *dev = imx8qxp_ldb->dev;
	unsigned long di_clk = adjusted_mode->clock * 1000;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	union phy_configure_opts opts = { };
	struct phy_configure_opts_lvds *phy_cfg = &opts.lvds;
	u32 chno = ldb_ch->chno;
	int ret;

	ret = pm_runtime_get_sync(dev);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to get runtime PM sync: %d\n", ret);

	ret = phy_init(imx8qxp_ldb_ch->phy);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to initialize PHY: %d\n", ret);

	ret = phy_set_mode(imx8qxp_ldb_ch->phy, PHY_MODE_LVDS);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to set PHY mode: %d\n", ret);

	if (is_split && companion) {
		companion_ldb_ch = bridge_to_ldb_ch(companion);

		companion_ldb_ch->in_bus_format = ldb_ch->in_bus_format;
		companion_ldb_ch->out_bus_format = ldb_ch->out_bus_format;
	}

	clk_set_rate(imx8qxp_ldb->clk_bypass, di_clk);
	clk_set_rate(imx8qxp_ldb->clk_pixel, di_clk);

	imx8qxp_ldb_set_phy_cfg(imx8qxp_ldb, di_clk, is_split, phy_cfg);
	ret = phy_configure(imx8qxp_ldb_ch->phy, &opts);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to configure PHY: %d\n", ret);

	if (chno == 0)
		ldb->ldb_ctrl &= ~LDB_CH_SEL;
	else
		ldb->ldb_ctrl |= LDB_CH_SEL;

	/* input VSYNC signal from pixel link is active low */
	if (imx8qxp_ldb_ch->di_id == 0)
		ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW;
	else
		ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW;

	/*
	 * For split mode, settle input VSYNC signal polarity and
	 * channel selection down early.
	 */
	if (is_split)
		regmap_write(ldb->regmap, ldb->ctrl_reg, ldb->ldb_ctrl);

	ldb_bridge_mode_set_helper(bridge, mode, adjusted_mode);

	if (adjusted_mode->flags & DRM_MODE_FLAG_NVSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL, CH_VSYNC_M(chno), 0);
	else if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL,
				   CH_VSYNC_M(chno), CH_PVSYNC(chno));

	if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL, CH_HSYNC_M(chno), 0);
	else if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL,
				   CH_HSYNC_M(chno), CH_PHSYNC(chno));

	if (is_split && companion)
		companion->funcs->mode_set(companion, mode, adjusted_mode);
}

static void
imx8qxp_ldb_bridge_atomic_pre_enable(struct drm_bridge *bridge,
				     struct drm_bridge_state *old_bridge_state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
	struct drm_bridge *companion = imx8qxp_ldb->companion;
	bool is_split = ldb_channel_is_split_link(ldb_ch);

	clk_prepare_enable(imx8qxp_ldb->clk_pixel);
	clk_prepare_enable(imx8qxp_ldb->clk_bypass);

	if (is_split && companion)
		companion->funcs->atomic_pre_enable(companion, old_bridge_state);
}

static void
imx8qxp_ldb_bridge_atomic_enable(struct drm_bridge *bridge,
				 struct drm_bridge_state *old_bridge_state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
					base_to_imx8qxp_ldb_channel(ldb_ch);
	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
	struct drm_bridge *companion = imx8qxp_ldb->companion;
	struct device *dev = imx8qxp_ldb->dev;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	int ret;

	if (ldb_ch->chno == 0 || is_split) {
		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
		ldb->ldb_ctrl |= imx8qxp_ldb_ch->di_id == 0 ?
				LDB_CH0_MODE_EN_TO_DI0 : LDB_CH0_MODE_EN_TO_DI1;
	}
	if (ldb_ch->chno == 1 || is_split) {
		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
		ldb->ldb_ctrl |= imx8qxp_ldb_ch->di_id == 0 ?
				LDB_CH1_MODE_EN_TO_DI0 : LDB_CH1_MODE_EN_TO_DI1;
	}

	ldb_bridge_enable_helper(bridge);

	ret = phy_power_on(imx8qxp_ldb_ch->phy);
	if (ret)
		DRM_DEV_ERROR(dev, "failed to power on PHY: %d\n", ret);

	if (is_split && companion)
		companion->funcs->atomic_enable(companion, old_bridge_state);
}

static void
imx8qxp_ldb_bridge_atomic_disable(struct drm_bridge *bridge,
				  struct drm_bridge_state *old_bridge_state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
					base_to_imx8qxp_ldb_channel(ldb_ch);
	struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb);
	struct drm_bridge *companion = imx8qxp_ldb->companion;
	struct device *dev = imx8qxp_ldb->dev;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	int ret;

	ret = phy_power_off(imx8qxp_ldb_ch->phy);
	if (ret)
		DRM_DEV_ERROR(dev, "failed to power off PHY: %d\n", ret);

	ret = phy_exit(imx8qxp_ldb_ch->phy);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to teardown PHY: %d\n", ret);

	ldb_bridge_disable_helper(bridge);

	clk_disable_unprepare(imx8qxp_ldb->clk_bypass);
	clk_disable_unprepare(imx8qxp_ldb->clk_pixel);

	if (is_split && companion)
		companion->funcs->atomic_disable(companion, old_bridge_state);

	ret = pm_runtime_put(dev);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to put runtime PM: %d\n", ret);
}

static const u32 imx8qxp_ldb_bus_output_fmts[] = {
	MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
	MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
	MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,
	MEDIA_BUS_FMT_FIXED,
};

static bool imx8qxp_ldb_bus_output_fmt_supported(u32 fmt)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(imx8qxp_ldb_bus_output_fmts); i++) {
		if (imx8qxp_ldb_bus_output_fmts[i] == fmt)
			return true;
	}

	return false;
}

static u32 *
imx8qxp_ldb_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
					     struct drm_bridge_state *bridge_state,
					     struct drm_crtc_state *crtc_state,
					     struct drm_connector_state *conn_state,
					     u32 output_fmt,
					     unsigned int *num_input_fmts)
{
	struct drm_display_info *di;
	const struct drm_format_info *finfo;
	u32 *input_fmts;

	if (!imx8qxp_ldb_bus_output_fmt_supported(output_fmt))
		return NULL;

	*num_input_fmts = 1;

	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
	if (!input_fmts)
		return NULL;

	switch (output_fmt) {
	case MEDIA_BUS_FMT_FIXED:
		di = &conn_state->connector->display_info;

		/*
		 * Look at the first bus format to determine input format.
		 * Default to MEDIA_BUS_FMT_RGB888_1X24, if no match.
		 */
		if (di->num_bus_formats) {
			finfo = drm_format_info(di->bus_formats[0]);

			input_fmts[0] = finfo->depth == 18 ?
					MEDIA_BUS_FMT_RGB666_1X24_CPADHI :
					MEDIA_BUS_FMT_RGB888_1X24;
		} else {
			input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
		}
		break;
	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X24_CPADHI;
		break;
	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
		break;
	default:
		kfree(input_fmts);
		input_fmts = NULL;
		break;
	}

	return input_fmts;
}

static u32 *
imx8qxp_ldb_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
					      struct drm_bridge_state *bridge_state,
					      struct drm_crtc_state *crtc_state,
					      struct drm_connector_state *conn_state,
					      unsigned int *num_output_fmts)
{
	*num_output_fmts = ARRAY_SIZE(imx8qxp_ldb_bus_output_fmts);
	return kmemdup(imx8qxp_ldb_bus_output_fmts,
			sizeof(imx8qxp_ldb_bus_output_fmts), GFP_KERNEL);
}

static enum drm_mode_status
imx8qxp_ldb_bridge_mode_valid(struct drm_bridge *bridge,
			      const struct drm_display_info *info,
			      const struct drm_display_mode *mode)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	bool is_single = ldb_channel_is_single_link(ldb_ch);

	if (mode->clock > 170000)
		return MODE_CLOCK_HIGH;

	if (mode->clock > 150000 && is_single)
		return MODE_CLOCK_HIGH;

	return MODE_OK;
}

static const struct drm_bridge_funcs imx8qxp_ldb_bridge_funcs = {
	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
	.atomic_reset		= drm_atomic_helper_bridge_reset,
	.mode_valid		= imx8qxp_ldb_bridge_mode_valid,
	.attach			= ldb_bridge_attach_helper,
	.atomic_check		= imx8qxp_ldb_bridge_atomic_check,
	.mode_set		= imx8qxp_ldb_bridge_mode_set,
	.atomic_pre_enable	= imx8qxp_ldb_bridge_atomic_pre_enable,
	.atomic_enable		= imx8qxp_ldb_bridge_atomic_enable,
	.atomic_disable		= imx8qxp_ldb_bridge_atomic_disable,
	.atomic_get_input_bus_fmts =
			imx8qxp_ldb_bridge_atomic_get_input_bus_fmts,
	.atomic_get_output_bus_fmts =
			imx8qxp_ldb_bridge_atomic_get_output_bus_fmts,
};

static int imx8qxp_ldb_set_di_id(struct imx8qxp_ldb *imx8qxp_ldb)
{
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
			 &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
	struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base;
	struct device_node *ep, *remote;
	struct device *dev = imx8qxp_ldb->dev;
	struct of_endpoint endpoint;
	int ret;

	ep = of_graph_get_endpoint_by_regs(ldb_ch->np, 0, -1);
	if (!ep) {
		DRM_DEV_ERROR(dev, "failed to get port0 endpoint\n");
		return -EINVAL;
	}

	remote = of_graph_get_remote_endpoint(ep);
	of_node_put(ep);
	if (!remote) {
		DRM_DEV_ERROR(dev, "failed to get port0 remote endpoint\n");
		return -EINVAL;
	}

	ret = of_graph_parse_endpoint(remote, &endpoint);
	of_node_put(remote);
	if (ret) {
		DRM_DEV_ERROR(dev, "failed to parse port0 remote endpoint: %d\n",
			      ret);
		return ret;
	}

	imx8qxp_ldb_ch->di_id = endpoint.id;

	return 0;
}

static int
imx8qxp_ldb_check_chno_and_dual_link(struct ldb_channel *ldb_ch, int link)
{
	if ((link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS && ldb_ch->chno != 0) ||
	    (link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS && ldb_ch->chno != 1))
		return -EINVAL;

	return 0;
}

static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb)
{
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch =
			 &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno];
	struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base;
	struct ldb_channel *companion_ldb_ch;
	struct device_node *companion;
	struct device_node *child;
	struct device_node *companion_port = NULL;
	struct device_node *port1, *port2;
	struct device *dev = imx8qxp_ldb->dev;
	const struct of_device_id *match;
	u32 i;
	int dual_link;
	int ret;

	/* Locate the companion LDB for dual-link operation, if any. */
	companion = of_parse_phandle(dev->of_node, "fsl,companion-ldb", 0);
	if (!companion)
		return 0;

	if (!of_device_is_available(companion)) {
		DRM_DEV_ERROR(dev, "companion LDB is not available\n");
		ret = -ENODEV;
		goto out;
	}

	/*
	 * Sanity check: the companion bridge must have the same compatible
	 * string.
	 */
	match = of_match_device(dev->driver->of_match_table, dev);
	if (!of_device_is_compatible(companion, match->compatible)) {
		DRM_DEV_ERROR(dev, "companion LDB is incompatible\n");
		ret = -ENXIO;
		goto out;
	}

	for_each_available_child_of_node(companion, child) {
		ret = of_property_read_u32(child, "reg", &i);
		if (ret || i > MAX_LDB_CHAN_NUM - 1) {
			DRM_DEV_ERROR(dev,
				      "invalid channel node address: %u\n", i);
			ret = -EINVAL;
			of_node_put(child);
			goto out;
		}

		/*
		 * Channel numbers have to be different, because channel0
		 * transmits odd pixels and channel1 transmits even pixels.
		 */
		if (i == (ldb_ch->chno ^ 0x1)) {
			companion_port = child;
			break;
		}
	}

	if (!companion_port) {
		DRM_DEV_ERROR(dev,
			      "failed to find companion LDB channel port\n");
		ret = -EINVAL;
		goto out;
	}

	/*
	 * We need to work out if the sink is expecting us to function in
	 * dual-link mode.  We do this by looking at the DT port nodes we are
	 * connected to.  If they are marked as expecting odd pixels and
	 * even pixels than we need to enable LDB split mode.
	 */
	port1 = of_graph_get_port_by_id(ldb_ch->np, 1);
	port2 = of_graph_get_port_by_id(companion_port, 1);
	dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
	of_node_put(port1);
	of_node_put(port2);

	switch (dual_link) {
	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
		ldb_ch->link_type = LDB_CH_DUAL_LINK_ODD_EVEN_PIXELS;
		break;
	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
		ldb_ch->link_type = LDB_CH_DUAL_LINK_EVEN_ODD_PIXELS;
		break;
	default:
		ret = dual_link;
		DRM_DEV_ERROR(dev,
			      "failed to get dual link pixel order: %d\n", ret);
		goto out;
	}

	ret = imx8qxp_ldb_check_chno_and_dual_link(ldb_ch, dual_link);
	if (ret < 0) {
		DRM_DEV_ERROR(dev,
			      "unmatched channel number(%u) vs dual link(%d)\n",
			      ldb_ch->chno, dual_link);
		goto out;
	}

	imx8qxp_ldb->companion = of_drm_find_bridge(companion_port);
	if (!imx8qxp_ldb->companion) {
		ret = -EPROBE_DEFER;
		DRM_DEV_DEBUG_DRIVER(dev,
				     "failed to find bridge for companion bridge: %d\n",
				     ret);
		goto out;
	}

	DRM_DEV_DEBUG_DRIVER(dev,
			     "dual-link configuration detected (companion bridge %pOF)\n",
			     companion);

	companion_ldb_ch = bridge_to_ldb_ch(imx8qxp_ldb->companion);
	companion_ldb_ch->link_type = ldb_ch->link_type;
out:
	of_node_put(companion_port);
	of_node_put(companion);
	return ret;
}

static int imx8qxp_ldb_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct imx8qxp_ldb *imx8qxp_ldb;
	struct imx8qxp_ldb_channel *imx8qxp_ldb_ch;
	struct ldb *ldb;
	struct ldb_channel *ldb_ch;
	int ret, i;

	imx8qxp_ldb = devm_kzalloc(dev, sizeof(*imx8qxp_ldb), GFP_KERNEL);
	if (!imx8qxp_ldb)
		return -ENOMEM;

	imx8qxp_ldb->clk_pixel = devm_clk_get(dev, "pixel");
	if (IS_ERR(imx8qxp_ldb->clk_pixel)) {
		ret = PTR_ERR(imx8qxp_ldb->clk_pixel);
		if (ret != -EPROBE_DEFER)
			DRM_DEV_ERROR(dev,
				      "failed to get pixel clock: %d\n", ret);
		return ret;
	}

	imx8qxp_ldb->clk_bypass = devm_clk_get(dev, "bypass");
	if (IS_ERR(imx8qxp_ldb->clk_bypass)) {
		ret = PTR_ERR(imx8qxp_ldb->clk_bypass);
		if (ret != -EPROBE_DEFER)
			DRM_DEV_ERROR(dev,
				      "failed to get bypass clock: %d\n", ret);
		return ret;
	}

	imx8qxp_ldb->dev = dev;

	ldb = &imx8qxp_ldb->base;
	ldb->dev = dev;
	ldb->ctrl_reg = 0xe0;

	for (i = 0; i < MAX_LDB_CHAN_NUM; i++)
		ldb->channel[i] = &imx8qxp_ldb->channel[i].base;

	ret = ldb_init_helper(ldb);
	if (ret)
		return ret;

	if (ldb->available_ch_cnt == 0) {
		DRM_DEV_DEBUG_DRIVER(dev, "no available channel\n");
		return 0;
	} else if (ldb->available_ch_cnt > 1) {
		DRM_DEV_ERROR(dev, "invalid available channel number(%u)\n",
			      ldb->available_ch_cnt);
		return -EINVAL;
	}

	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
		imx8qxp_ldb_ch = &imx8qxp_ldb->channel[i];
		ldb_ch = &imx8qxp_ldb_ch->base;

		if (ldb_ch->is_available) {
			imx8qxp_ldb->active_chno = ldb_ch->chno;
			break;
		}
	}

	imx8qxp_ldb_ch->phy = devm_of_phy_get(dev, ldb_ch->np, "lvds_phy");
	if (IS_ERR(imx8qxp_ldb_ch->phy)) {
		ret = PTR_ERR(imx8qxp_ldb_ch->phy);
		if (ret != -EPROBE_DEFER)
			DRM_DEV_ERROR(dev, "failed to get channel%d PHY: %d\n",
				      imx8qxp_ldb->active_chno, ret);
		return ret;
	}

	ret = ldb_find_next_bridge_helper(ldb);
	if (ret)
		return ret;

	ret = imx8qxp_ldb_set_di_id(imx8qxp_ldb);
	if (ret)
		return ret;

	ret = imx8qxp_ldb_parse_dt_companion(imx8qxp_ldb);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, imx8qxp_ldb);
	pm_runtime_enable(dev);

	ldb_add_bridge_helper(ldb, &imx8qxp_ldb_bridge_funcs);

	return ret;
}

static void imx8qxp_ldb_remove(struct platform_device *pdev)
{
	struct imx8qxp_ldb *imx8qxp_ldb = platform_get_drvdata(pdev);
	struct ldb *ldb = &imx8qxp_ldb->base;

	ldb_remove_bridge_helper(ldb);

	pm_runtime_disable(&pdev->dev);
}

static int __maybe_unused imx8qxp_ldb_runtime_suspend(struct device *dev)
{
	return 0;
}

static int __maybe_unused imx8qxp_ldb_runtime_resume(struct device *dev)
{
	struct imx8qxp_ldb *imx8qxp_ldb = dev_get_drvdata(dev);
	struct ldb *ldb = &imx8qxp_ldb->base;

	/* disable LDB by resetting the control register to POR default */
	regmap_write(ldb->regmap, ldb->ctrl_reg, 0);

	return 0;
}

static const struct dev_pm_ops imx8qxp_ldb_pm_ops = {
	SET_RUNTIME_PM_OPS(imx8qxp_ldb_runtime_suspend,
			   imx8qxp_ldb_runtime_resume, NULL)
};

static const struct of_device_id imx8qxp_ldb_dt_ids[] = {
	{ .compatible = "fsl,imx8qxp-ldb" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx8qxp_ldb_dt_ids);

static struct platform_driver imx8qxp_ldb_driver = {
	.probe	= imx8qxp_ldb_probe,
	.remove_new = imx8qxp_ldb_remove,
	.driver	= {
		.pm = &imx8qxp_ldb_pm_ops,
		.name = DRIVER_NAME,
		.of_match_table = imx8qxp_ldb_dt_ids,
	},
};
module_platform_driver(imx8qxp_ldb_driver);

MODULE_DESCRIPTION("i.MX8QXP LVDS Display Bridge(LDB)/Pixel Mapper bridge driver");
MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);