/*
 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include "msm_kms.h"
#include "dsi.h"

#define DSI_CLOCK_MASTER        DSI_0
#define DSI_CLOCK_SLAVE         DSI_1

#define DSI_LEFT                DSI_0
#define DSI_RIGHT               DSI_1

/* According to the current drm framework sequence, take the encoder of
 * DSI_1 as master encoder
 */
#define DSI_ENCODER_MASTER      DSI_1
#define DSI_ENCODER_SLAVE       DSI_0

struct msm_dsi_manager {
        struct msm_dsi *dsi[DSI_MAX];

        bool is_dual_dsi;
        bool is_sync_needed;
        int master_dsi_link_id;
};

static struct msm_dsi_manager msm_dsim_glb;

#define IS_DUAL_DSI()           (msm_dsim_glb.is_dual_dsi)
#define IS_SYNC_NEEDED()        (msm_dsim_glb.is_sync_needed)
#define IS_MASTER_DSI_LINK(id)  (msm_dsim_glb.master_dsi_link_id == id)

static inline struct msm_dsi *dsi_mgr_get_dsi(int id)
{
        return msm_dsim_glb.dsi[id];
}

static inline struct msm_dsi *dsi_mgr_get_other_dsi(int id)
{
        return msm_dsim_glb.dsi[(id + 1) % DSI_MAX];
}

static int dsi_mgr_parse_dual_dsi(struct device_node *np, int id)
{
        struct msm_dsi_manager *msm_dsim = &msm_dsim_glb;

        /* We assume 2 dsi nodes have the same information of dual-dsi and
         * sync-mode, and only one node specifies master in case of dual mode.
         */
        if (!msm_dsim->is_dual_dsi)
                msm_dsim->is_dual_dsi = of_property_read_bool(
                                                np, "qcom,dual-dsi-mode");

        if (msm_dsim->is_dual_dsi) {
                if (of_property_read_bool(np, "qcom,master-dsi"))
                        msm_dsim->master_dsi_link_id = id;
                if (!msm_dsim->is_sync_needed)
                        msm_dsim->is_sync_needed = of_property_read_bool(
                                        np, "qcom,sync-dual-dsi");
        }

        return 0;
}

static int dsi_mgr_setup_components(int id)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *other_dsi = dsi_mgr_get_other_dsi(id);
        struct msm_dsi *clk_master_dsi = dsi_mgr_get_dsi(DSI_CLOCK_MASTER);
        struct msm_dsi *clk_slave_dsi = dsi_mgr_get_dsi(DSI_CLOCK_SLAVE);
        struct msm_dsi_pll *src_pll;
        int ret;

        if (!IS_DUAL_DSI()) {
                ret = msm_dsi_host_register(msm_dsi->host, true);
                if (ret)
                        return ret;

                msm_dsi_phy_set_usecase(msm_dsi->phy, MSM_DSI_PHY_STANDALONE);
                src_pll = msm_dsi_phy_get_pll(msm_dsi->phy);
                ret = msm_dsi_host_set_src_pll(msm_dsi->host, src_pll);
        } else if (!other_dsi) {
                ret = 0;
        } else {
                struct msm_dsi *master_link_dsi = IS_MASTER_DSI_LINK(id) ?
                                                        msm_dsi : other_dsi;
                struct msm_dsi *slave_link_dsi = IS_MASTER_DSI_LINK(id) ?
                                                        other_dsi : msm_dsi;
                /* Register slave host first, so that slave DSI device
                 * has a chance to probe, and do not block the master
                 * DSI device's probe.
                 * Also, do not check defer for the slave host,
                 * because only master DSI device adds the panel to global
                 * panel list. The panel's device is the master DSI device.
                 */
                ret = msm_dsi_host_register(slave_link_dsi->host, false);
                if (ret)
                        return ret;
                ret = msm_dsi_host_register(master_link_dsi->host, true);
                if (ret)
                        return ret;

                /* PLL0 is to drive both 2 DSI link clocks in Dual DSI mode. */
                msm_dsi_phy_set_usecase(clk_master_dsi->phy,
                                        MSM_DSI_PHY_MASTER);
                msm_dsi_phy_set_usecase(clk_slave_dsi->phy,
                                        MSM_DSI_PHY_SLAVE);
                src_pll = msm_dsi_phy_get_pll(clk_master_dsi->phy);
                ret = msm_dsi_host_set_src_pll(msm_dsi->host, src_pll);
                if (ret)
                        return ret;
                ret = msm_dsi_host_set_src_pll(other_dsi->host, src_pll);
        }

        return ret;
}

static int enable_phy(struct msm_dsi *msm_dsi, int src_pll_id,
                      struct msm_dsi_phy_shared_timings *shared_timings)
{
        struct msm_dsi_phy_clk_request clk_req;
        int ret;

        msm_dsi_host_get_phy_clk_req(msm_dsi->host, &clk_req);

        ret = msm_dsi_phy_enable(msm_dsi->phy, src_pll_id, &clk_req);
        msm_dsi_phy_get_shared_timings(msm_dsi->phy, shared_timings);

        return ret;
}

static int
dsi_mgr_phy_enable(int id,
                   struct msm_dsi_phy_shared_timings shared_timings[DSI_MAX])
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *mdsi = dsi_mgr_get_dsi(DSI_CLOCK_MASTER);
        struct msm_dsi *sdsi = dsi_mgr_get_dsi(DSI_CLOCK_SLAVE);
        int src_pll_id = IS_DUAL_DSI() ? DSI_CLOCK_MASTER : id;
        int ret;

        /* In case of dual DSI, some registers in PHY1 have been programmed
         * during PLL0 clock's set_rate. The PHY1 reset called by host1 here
         * will silently reset those PHY1 registers. Therefore we need to reset
         * and enable both PHYs before any PLL clock operation.
         */
        if (IS_DUAL_DSI() && mdsi && sdsi) {
                if (!mdsi->phy_enabled && !sdsi->phy_enabled) {
                        msm_dsi_host_reset_phy(mdsi->host);
                        msm_dsi_host_reset_phy(sdsi->host);

                        ret = enable_phy(mdsi, src_pll_id,
                                         &shared_timings[DSI_CLOCK_MASTER]);
                        if (ret)
                                return ret;
                        ret = enable_phy(sdsi, src_pll_id,
                                         &shared_timings[DSI_CLOCK_SLAVE]);
                        if (ret) {
                                msm_dsi_phy_disable(mdsi->phy);
                                return ret;
                        }
                }
        } else {
                msm_dsi_host_reset_phy(msm_dsi->host);
                ret = enable_phy(msm_dsi, src_pll_id, &shared_timings[id]);
                if (ret)
                        return ret;
        }

        msm_dsi->phy_enabled = true;

        return 0;
}

static void dsi_mgr_phy_disable(int id)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *mdsi = dsi_mgr_get_dsi(DSI_CLOCK_MASTER);
        struct msm_dsi *sdsi = dsi_mgr_get_dsi(DSI_CLOCK_SLAVE);

        /* disable DSI phy
         * In dual-dsi configuration, the phy should be disabled for the
         * first controller only when the second controller is disabled.
         */
        msm_dsi->phy_enabled = false;
        if (IS_DUAL_DSI() && mdsi && sdsi) {
                if (!mdsi->phy_enabled && !sdsi->phy_enabled) {
                        msm_dsi_phy_disable(sdsi->phy);
                        msm_dsi_phy_disable(mdsi->phy);
                }
        } else {
                msm_dsi_phy_disable(msm_dsi->phy);
        }
}

struct dsi_connector {
        struct drm_connector base;
        int id;
};

struct dsi_bridge {
        struct drm_bridge base;
        int id;
};

#define to_dsi_connector(x) container_of(x, struct dsi_connector, base)
#define to_dsi_bridge(x) container_of(x, struct dsi_bridge, base)

static inline int dsi_mgr_connector_get_id(struct drm_connector *connector)
{
        struct dsi_connector *dsi_connector = to_dsi_connector(connector);
        return dsi_connector->id;
}

static int dsi_mgr_bridge_get_id(struct drm_bridge *bridge)
{
        struct dsi_bridge *dsi_bridge = to_dsi_bridge(bridge);
        return dsi_bridge->id;
}

static enum drm_connector_status dsi_mgr_connector_detect(
                struct drm_connector *connector, bool force)
{
        int id = dsi_mgr_connector_get_id(connector);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *other_dsi = dsi_mgr_get_other_dsi(id);
        struct msm_drm_private *priv = connector->dev->dev_private;
        struct msm_kms *kms = priv->kms;

        DBG("id=%d", id);
        if (!msm_dsi->panel) {
                msm_dsi->panel = msm_dsi_host_get_panel(msm_dsi->host,
                                                &msm_dsi->device_flags);

                /* There is only 1 panel in the global panel list
                 * for dual DSI mode. Therefore slave dsi should get
                 * the drm_panel instance from master dsi, and
                 * keep using the panel flags got from the current DSI link.
                 */
                if (!msm_dsi->panel && IS_DUAL_DSI() &&
                        !IS_MASTER_DSI_LINK(id) && other_dsi)
                        msm_dsi->panel = msm_dsi_host_get_panel(
                                        other_dsi->host, NULL);


                if (msm_dsi->panel && kms->funcs->set_encoder_mode) {
                        bool cmd_mode = !(msm_dsi->device_flags &
                                          MIPI_DSI_MODE_VIDEO);
                        struct drm_encoder *encoder =
                                        msm_dsi_get_encoder(msm_dsi);

                        kms->funcs->set_encoder_mode(kms, encoder, cmd_mode);
                }

                if (msm_dsi->panel && IS_DUAL_DSI())
                        drm_object_attach_property(&connector->base,
                                connector->dev->mode_config.tile_property, 0);

                /* Set split display info to kms once dual DSI panel is
                 * connected to both hosts.
                 */
                if (msm_dsi->panel && IS_DUAL_DSI() &&
                        other_dsi && other_dsi->panel) {
                        bool cmd_mode = !(msm_dsi->device_flags &
                                                MIPI_DSI_MODE_VIDEO);
                        struct drm_encoder *encoder = msm_dsi_get_encoder(
                                        dsi_mgr_get_dsi(DSI_ENCODER_MASTER));
                        struct drm_encoder *slave_enc = msm_dsi_get_encoder(
                                        dsi_mgr_get_dsi(DSI_ENCODER_SLAVE));

                        if (kms->funcs->set_split_display)
                                kms->funcs->set_split_display(kms, encoder,
                                                        slave_enc, cmd_mode);
                        else
                                pr_err("mdp does not support dual DSI\n");
                }
        }

        return msm_dsi->panel ? connector_status_connected :
                connector_status_disconnected;
}

static void dsi_mgr_connector_destroy(struct drm_connector *connector)
{
        struct dsi_connector *dsi_connector = to_dsi_connector(connector);

        DBG("");

        drm_connector_cleanup(connector);

        kfree(dsi_connector);
}

static void dsi_dual_connector_fix_modes(struct drm_connector *connector)
{
        struct drm_display_mode *mode, *m;

        /* Only support left-right mode */
        list_for_each_entry_safe(mode, m, &connector->probed_modes, head) {
                mode->clock >>= 1;
                mode->hdisplay >>= 1;
                mode->hsync_start >>= 1;
                mode->hsync_end >>= 1;
                mode->htotal >>= 1;
                drm_mode_set_name(mode);
        }
}

static int dsi_dual_connector_tile_init(
                        struct drm_connector *connector, int id)
{
        struct drm_display_mode *mode;
        /* Fake topology id */
        char topo_id[8] = {'M', 'S', 'M', 'D', 'U', 'D', 'S', 'I'};

        if (connector->tile_group) {
                DBG("Tile property has been initialized");
                return 0;
        }

        /* Use the first mode only for now */
        mode = list_first_entry(&connector->probed_modes,
                                struct drm_display_mode,
                                head);
        if (!mode)
                return -EINVAL;

        connector->tile_group = drm_mode_get_tile_group(
                                        connector->dev, topo_id);
        if (!connector->tile_group)
                connector->tile_group = drm_mode_create_tile_group(
                                        connector->dev, topo_id);
        if (!connector->tile_group) {
                pr_err("%s: failed to create tile group\n", __func__);
                return -ENOMEM;
        }

        connector->has_tile = true;
        connector->tile_is_single_monitor = true;

        /* mode has been fixed */
        connector->tile_h_size = mode->hdisplay;
        connector->tile_v_size = mode->vdisplay;

        /* Only support left-right mode */
        connector->num_h_tile = 2;
        connector->num_v_tile = 1;

        connector->tile_v_loc = 0;
        connector->tile_h_loc = (id == DSI_RIGHT) ? 1 : 0;

        return 0;
}

static int dsi_mgr_connector_get_modes(struct drm_connector *connector)
{
        int id = dsi_mgr_connector_get_id(connector);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct drm_panel *panel = msm_dsi->panel;
        int ret, num;

        if (!panel)
                return 0;

        /* Since we have 2 connectors, but only 1 drm_panel in dual DSI mode,
         * panel should not attach to any connector.
         * Only temporarily attach panel to the current connector here,
         * to let panel set mode to this connector.
         */
        drm_panel_attach(panel, connector);
        num = drm_panel_get_modes(panel);
        drm_panel_detach(panel);
        if (!num)
                return 0;

        if (IS_DUAL_DSI()) {
                /* report half resolution to user */
                dsi_dual_connector_fix_modes(connector);
                ret = dsi_dual_connector_tile_init(connector, id);
                if (ret)
                        return ret;
                ret = drm_mode_connector_set_tile_property(connector);
                if (ret) {
                        pr_err("%s: set tile property failed, %d\n",
                                        __func__, ret);
                        return ret;
                }
        }

        return num;
}

static int dsi_mgr_connector_mode_valid(struct drm_connector *connector,
                                struct drm_display_mode *mode)
{
        int id = dsi_mgr_connector_get_id(connector);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct drm_encoder *encoder = msm_dsi_get_encoder(msm_dsi);
        struct msm_drm_private *priv = connector->dev->dev_private;
        struct msm_kms *kms = priv->kms;
        long actual, requested;

        DBG("");
        requested = 1000 * mode->clock;
        actual = kms->funcs->round_pixclk(kms, requested, encoder);

        DBG("requested=%ld, actual=%ld", requested, actual);
        if (actual != requested)
                return MODE_CLOCK_RANGE;

        return MODE_OK;
}

static struct drm_encoder *
dsi_mgr_connector_best_encoder(struct drm_connector *connector)
{
        int id = dsi_mgr_connector_get_id(connector);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);

        DBG("");
        return msm_dsi_get_encoder(msm_dsi);
}

static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
{
        int id = dsi_mgr_bridge_get_id(bridge);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
        struct mipi_dsi_host *host = msm_dsi->host;
        struct drm_panel *panel = msm_dsi->panel;
        struct msm_dsi_phy_shared_timings phy_shared_timings[DSI_MAX];
        bool is_dual_dsi = IS_DUAL_DSI();
        int ret;

        DBG("id=%d", id);
        if (!msm_dsi_device_connected(msm_dsi))
                return;

        ret = dsi_mgr_phy_enable(id, phy_shared_timings);
        if (ret)
                goto phy_en_fail;

        /* Do nothing with the host if it is DSI 1 in case of dual DSI */
        if (is_dual_dsi && (DSI_1 == id))
                return;

        ret = msm_dsi_host_power_on(host, &phy_shared_timings[id]);
        if (ret) {
                pr_err("%s: power on host %d failed, %d\n", __func__, id, ret);
                goto host_on_fail;
        }

        if (is_dual_dsi && msm_dsi1) {
                ret = msm_dsi_host_power_on(msm_dsi1->host,
                                            &phy_shared_timings[DSI_1]);
                if (ret) {
                        pr_err("%s: power on host1 failed, %d\n",
                                                        __func__, ret);
                        goto host1_on_fail;
                }
        }

        /* Always call panel functions once, because even for dual panels,
         * there is only one drm_panel instance.
         */
        if (panel) {
                ret = drm_panel_prepare(panel);
                if (ret) {
                        pr_err("%s: prepare panel %d failed, %d\n", __func__,
                                                                id, ret);
                        goto panel_prep_fail;
                }
        }

        ret = msm_dsi_host_enable(host);
        if (ret) {
                pr_err("%s: enable host %d failed, %d\n", __func__, id, ret);
                goto host_en_fail;
        }

        if (is_dual_dsi && msm_dsi1) {
                ret = msm_dsi_host_enable(msm_dsi1->host);
                if (ret) {
                        pr_err("%s: enable host1 failed, %d\n", __func__, ret);
                        goto host1_en_fail;
                }
        }

        if (panel) {
                ret = drm_panel_enable(panel);
                if (ret) {
                        pr_err("%s: enable panel %d failed, %d\n", __func__, id,
                                                                        ret);
                        goto panel_en_fail;
                }
        }

        return;

panel_en_fail:
        if (is_dual_dsi && msm_dsi1)
                msm_dsi_host_disable(msm_dsi1->host);
host1_en_fail:
        msm_dsi_host_disable(host);
host_en_fail:
        if (panel)
                drm_panel_unprepare(panel);
panel_prep_fail:
        if (is_dual_dsi && msm_dsi1)
                msm_dsi_host_power_off(msm_dsi1->host);
host1_on_fail:
        msm_dsi_host_power_off(host);
host_on_fail:
        dsi_mgr_phy_disable(id);
phy_en_fail:
        return;
}

static void dsi_mgr_bridge_enable(struct drm_bridge *bridge)
{
        DBG("");
}

static void dsi_mgr_bridge_disable(struct drm_bridge *bridge)
{
        DBG("");
}

static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
{
        int id = dsi_mgr_bridge_get_id(bridge);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
        struct mipi_dsi_host *host = msm_dsi->host;
        struct drm_panel *panel = msm_dsi->panel;
        bool is_dual_dsi = IS_DUAL_DSI();
        int ret;

        DBG("id=%d", id);

        if (!msm_dsi_device_connected(msm_dsi))
                return;

        /*
         * Do nothing with the host if it is DSI 1 in case of dual DSI.
         * It is safe to call dsi_mgr_phy_disable() here because a single PHY
         * won't be diabled until both PHYs request disable.
         */
        if (is_dual_dsi && (DSI_1 == id))
                goto disable_phy;

        if (panel) {
                ret = drm_panel_disable(panel);
                if (ret)
                        pr_err("%s: Panel %d OFF failed, %d\n", __func__, id,
                                                                        ret);
        }

        ret = msm_dsi_host_disable(host);
        if (ret)
                pr_err("%s: host %d disable failed, %d\n", __func__, id, ret);

        if (is_dual_dsi && msm_dsi1) {
                ret = msm_dsi_host_disable(msm_dsi1->host);
                if (ret)
                        pr_err("%s: host1 disable failed, %d\n", __func__, ret);
        }

        if (panel) {
                ret = drm_panel_unprepare(panel);
                if (ret)
                        pr_err("%s: Panel %d unprepare failed,%d\n", __func__,
                                                                id, ret);
        }

        ret = msm_dsi_host_power_off(host);
        if (ret)
                pr_err("%s: host %d power off failed,%d\n", __func__, id, ret);

        if (is_dual_dsi && msm_dsi1) {
                ret = msm_dsi_host_power_off(msm_dsi1->host);
                if (ret)
                        pr_err("%s: host1 power off failed, %d\n",
                                                                __func__, ret);
        }

disable_phy:
        dsi_mgr_phy_disable(id);
}

static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
                struct drm_display_mode *mode,
                struct drm_display_mode *adjusted_mode)
{
        int id = dsi_mgr_bridge_get_id(bridge);
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *other_dsi = dsi_mgr_get_other_dsi(id);
        struct mipi_dsi_host *host = msm_dsi->host;
        bool is_dual_dsi = IS_DUAL_DSI();

        DBG("set mode: %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x",
                        mode->base.id, mode->name,
                        mode->vrefresh, mode->clock,
                        mode->hdisplay, mode->hsync_start,
                        mode->hsync_end, mode->htotal,
                        mode->vdisplay, mode->vsync_start,
                        mode->vsync_end, mode->vtotal,
                        mode->type, mode->flags);

        if (is_dual_dsi && (DSI_1 == id))
                return;

        msm_dsi_host_set_display_mode(host, adjusted_mode);
        if (is_dual_dsi && other_dsi)
                msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode);
}

static const struct drm_connector_funcs dsi_mgr_connector_funcs = {
        .detect = dsi_mgr_connector_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = dsi_mgr_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static const struct drm_connector_helper_funcs dsi_mgr_conn_helper_funcs = {
        .get_modes = dsi_mgr_connector_get_modes,
        .mode_valid = dsi_mgr_connector_mode_valid,
        .best_encoder = dsi_mgr_connector_best_encoder,
};

static const struct drm_bridge_funcs dsi_mgr_bridge_funcs = {
        .pre_enable = dsi_mgr_bridge_pre_enable,
        .enable = dsi_mgr_bridge_enable,
        .disable = dsi_mgr_bridge_disable,
        .post_disable = dsi_mgr_bridge_post_disable,
        .mode_set = dsi_mgr_bridge_mode_set,
};

/* initialize connector when we're connected to a drm_panel */
struct drm_connector *msm_dsi_manager_connector_init(u8 id)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct drm_connector *connector = NULL;
        struct dsi_connector *dsi_connector;
        int ret;

        dsi_connector = kzalloc(sizeof(*dsi_connector), GFP_KERNEL);
        if (!dsi_connector)
                return ERR_PTR(-ENOMEM);

        dsi_connector->id = id;

        connector = &dsi_connector->base;

        ret = drm_connector_init(msm_dsi->dev, connector,
                        &dsi_mgr_connector_funcs, DRM_MODE_CONNECTOR_DSI);
        if (ret)
                return ERR_PTR(ret);

        drm_connector_helper_add(connector, &dsi_mgr_conn_helper_funcs);

        /* Enable HPD to let hpd event is handled
         * when panel is attached to the host.
         */
        connector->polled = DRM_CONNECTOR_POLL_HPD;

        /* Display driver doesn't support interlace now. */
        connector->interlace_allowed = 0;
        connector->doublescan_allowed = 0;

        drm_mode_connector_attach_encoder(connector, msm_dsi->encoder);

        return connector;
}

/* initialize bridge */
struct drm_bridge *msm_dsi_manager_bridge_init(u8 id)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct drm_bridge *bridge = NULL;
        struct dsi_bridge *dsi_bridge;
        struct drm_encoder *encoder;
        int ret;

        dsi_bridge = devm_kzalloc(msm_dsi->dev->dev,
                                sizeof(*dsi_bridge), GFP_KERNEL);
        if (!dsi_bridge) {
                ret = -ENOMEM;
                goto fail;
        }

        dsi_bridge->id = id;

        encoder = msm_dsi->encoder;

        bridge = &dsi_bridge->base;
        bridge->funcs = &dsi_mgr_bridge_funcs;

        ret = drm_bridge_attach(encoder, bridge, NULL);
        if (ret)
                goto fail;

        return bridge;

fail:
        if (bridge)
                msm_dsi_manager_bridge_destroy(bridge);

        return ERR_PTR(ret);
}

struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct drm_device *dev = msm_dsi->dev;
        struct drm_encoder *encoder;
        struct drm_bridge *int_bridge, *ext_bridge;
        struct drm_connector *connector;
        struct list_head *connector_list;

        int_bridge = msm_dsi->bridge;
        ext_bridge = msm_dsi->external_bridge =
                        msm_dsi_host_get_bridge(msm_dsi->host);

        encoder = msm_dsi->encoder;

        /* link the internal dsi bridge to the external bridge */
        drm_bridge_attach(encoder, ext_bridge, int_bridge);

        /*
         * we need the drm_connector created by the external bridge
         * driver (or someone else) to feed it to our driver's
         * priv->connector[] list, mainly for msm_fbdev_init()
         */
        connector_list = &dev->mode_config.connector_list;

        list_for_each_entry(connector, connector_list, head) {
                int i;

                for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
                        if (connector->encoder_ids[i] == encoder->base.id)
                                return connector;
                }
        }

        return ERR_PTR(-ENODEV);
}

void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge)
{
}

int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *msm_dsi0 = dsi_mgr_get_dsi(DSI_0);
        struct mipi_dsi_host *host = msm_dsi->host;
        bool is_read = (msg->rx_buf && msg->rx_len);
        bool need_sync = (IS_SYNC_NEEDED() && !is_read);
        int ret;

        if (!msg->tx_buf || !msg->tx_len)
                return 0;

        /* In dual master case, panel requires the same commands sent to
         * both DSI links. Host issues the command trigger to both links
         * when DSI_1 calls the cmd transfer function, no matter it happens
         * before or after DSI_0 cmd transfer.
         */
        if (need_sync && (id == DSI_0))
                return is_read ? msg->rx_len : msg->tx_len;

        if (need_sync && msm_dsi0) {
                ret = msm_dsi_host_xfer_prepare(msm_dsi0->host, msg);
                if (ret) {
                        pr_err("%s: failed to prepare non-trigger host, %d\n",
                                __func__, ret);
                        return ret;
                }
        }
        ret = msm_dsi_host_xfer_prepare(host, msg);
        if (ret) {
                pr_err("%s: failed to prepare host, %d\n", __func__, ret);
                goto restore_host0;
        }

        ret = is_read ? msm_dsi_host_cmd_rx(host, msg) :
                        msm_dsi_host_cmd_tx(host, msg);

        msm_dsi_host_xfer_restore(host, msg);

restore_host0:
        if (need_sync && msm_dsi0)
                msm_dsi_host_xfer_restore(msm_dsi0->host, msg);

        return ret;
}

bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct msm_dsi *msm_dsi0 = dsi_mgr_get_dsi(DSI_0);
        struct mipi_dsi_host *host = msm_dsi->host;

        if (IS_SYNC_NEEDED() && (id == DSI_0))
                return false;

        if (IS_SYNC_NEEDED() && msm_dsi0)
                msm_dsi_host_cmd_xfer_commit(msm_dsi0->host, dma_base, len);

        msm_dsi_host_cmd_xfer_commit(host, dma_base, len);

        return true;
}

void msm_dsi_manager_attach_dsi_device(int id, u32 device_flags)
{
        struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
        struct drm_device *dev = msm_dsi->dev;
        struct msm_drm_private *priv;
        struct msm_kms *kms;
        struct drm_encoder *encoder;

        /*
         * drm_device pointer is assigned to msm_dsi only in the modeset_init
         * path. If mipi_dsi_attach() happens in DSI driver's probe path
         * (generally the case when we're connected to a drm_panel of the type
         * mipi_dsi_device), this would be NULL. In such cases, try to set the
         * encoder mode in the DSI connector's detect() op.
         */
        if (!dev)
                return;

        priv = dev->dev_private;
        kms = priv->kms;
        encoder = msm_dsi_get_encoder(msm_dsi);

        if (encoder && kms->funcs->set_encoder_mode)
                if (!(device_flags & MIPI_DSI_MODE_VIDEO))
                        kms->funcs->set_encoder_mode(kms, encoder, true);
}

int msm_dsi_manager_register(struct msm_dsi *msm_dsi)
{
        struct msm_dsi_manager *msm_dsim = &msm_dsim_glb;
        int id = msm_dsi->id;
        int ret;

        if (id > DSI_MAX) {
                pr_err("%s: invalid id %d\n", __func__, id);
                return -EINVAL;
        }

        if (msm_dsim->dsi[id]) {
                pr_err("%s: dsi%d already registered\n", __func__, id);
                return -EBUSY;
        }

        msm_dsim->dsi[id] = msm_dsi;

        ret = dsi_mgr_parse_dual_dsi(msm_dsi->pdev->dev.of_node, id);
        if (ret) {
                pr_err("%s: failed to parse dual DSI info\n", __func__);
                goto fail;
        }

        ret = dsi_mgr_setup_components(id);
        if (ret) {
                pr_err("%s: failed to register mipi dsi host for DSI %d\n",
                        __func__, id);
                goto fail;
        }

        return 0;

fail:
        msm_dsim->dsi[id] = NULL;
        return ret;
}

void msm_dsi_manager_unregister(struct msm_dsi *msm_dsi)
{
        struct msm_dsi_manager *msm_dsim = &msm_dsim_glb;

        if (msm_dsi->host)
                msm_dsi_host_unregister(msm_dsi->host);
        msm_dsim->dsi[msm_dsi->id] = NULL;
}