root/drivers/gpu/drm/bridge/imx/imx8qxp-ldb.c
// 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_bridge_destroy(struct drm_bridge *bridge)
{
        struct ldb_channel *ldb_ch = bridge->driver_private;
        struct imx8qxp_ldb *imx8qxp_ldb;

        if (!ldb_ch)
                return;

        imx8qxp_ldb = base_to_imx8qxp_ldb(ldb_ch->ldb);
        drm_bridge_put(imx8qxp_ldb->companion);
}

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_atomic_state *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, state);
}

static void imx8qxp_ldb_bridge_atomic_enable(struct drm_bridge *bridge,
                                             struct drm_atomic_state *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, state);
}

static void imx8qxp_ldb_bridge_atomic_disable(struct drm_bridge *bridge,
                                              struct drm_atomic_state *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, state);

        pm_runtime_put(dev);
}

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_obj(*input_fmts);
        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 = {
        .destroy                = imx8qxp_ldb_bridge_destroy,
        .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_and_get_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;

        for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
                imx8qxp_ldb->channel[i] =
                        devm_drm_bridge_alloc(dev, struct imx8qxp_ldb_channel, base.bridge,
                                              &imx8qxp_ldb_bridge_funcs);
                if (IS_ERR(imx8qxp_ldb->channel[i]))
                        return PTR_ERR(imx8qxp_ldb->channel[i]);
        }

        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);

        return 0;
}

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 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 = {
        RUNTIME_PM_OPS(NULL, 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 = imx8qxp_ldb_remove,
        .driver = {
                .pm = pm_ptr(&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);