// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018, The Linux Foundation. All rights reserved.
 */

#include <linux/device.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/media-bus-format.h>
#include <linux/regmap.h>

#include <drm/drm_probe_helper.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>

#include <video/videomode.h>

#define I2C_MAIN 0
#define I2C_ADDR_MAIN 0x48

#define I2C_CEC_DSI 1
#define I2C_ADDR_CEC_DSI 0x49

#define I2C_MAX_IDX 2

struct lt8912 {
        struct device *dev;
        struct drm_bridge bridge;
        struct drm_connector connector;

        struct i2c_client *i2c_client[I2C_MAX_IDX];
        struct regmap *regmap[I2C_MAX_IDX];

        struct device_node *host_node;

        struct mipi_dsi_device *dsi;

        struct gpio_desc *gp_reset;

        struct videomode mode;

        struct regulator_bulk_data supplies[7];

        u8 data_lanes;
        bool is_power_on;
};

static int lt8912_write_init_config(struct lt8912 *lt)
{
        const struct reg_sequence seq[] = {
                /* Digital clock en*/
                {0x08, 0xff},
                {0x09, 0xff},
                {0x0a, 0xff},
                {0x0b, 0x7c},
                {0x0c, 0xff},
                {0x42, 0x04},

                /*Tx Analog*/
                {0x31, 0xb1},
                {0x32, 0xb1},
                {0x33, 0x0e},
                {0x37, 0x00},
                {0x38, 0x22},
                {0x60, 0x82},

                /*Cbus Analog*/
                {0x39, 0x45},
                {0x3a, 0x00},
                {0x3b, 0x00},

                /*HDMI Pll Analog*/
                {0x44, 0x31},
                {0x55, 0x44},
                {0x57, 0x01},
                {0x5a, 0x02},

                /*MIPI Analog*/
                {0x3e, 0xd6},
                {0x3f, 0xd4},
                {0x41, 0x3c},
                {0xB2, 0x00},
        };

        return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
}

static int lt8912_write_mipi_basic_config(struct lt8912 *lt)
{
        const struct reg_sequence seq[] = {
                {0x12, 0x04},
                {0x14, 0x00},
                {0x15, 0x00},
                {0x1a, 0x03},
                {0x1b, 0x03},
        };

        return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
};

static int lt8912_write_dds_config(struct lt8912 *lt)
{
        const struct reg_sequence seq[] = {
                {0x4e, 0xff},
                {0x4f, 0x56},
                {0x50, 0x69},
                {0x51, 0x80},
                {0x1f, 0x5e},
                {0x20, 0x01},
                {0x21, 0x2c},
                {0x22, 0x01},
                {0x23, 0xfa},
                {0x24, 0x00},
                {0x25, 0xc8},
                {0x26, 0x00},
                {0x27, 0x5e},
                {0x28, 0x01},
                {0x29, 0x2c},
                {0x2a, 0x01},
                {0x2b, 0xfa},
                {0x2c, 0x00},
                {0x2d, 0xc8},
                {0x2e, 0x00},
                {0x42, 0x64},
                {0x43, 0x00},
                {0x44, 0x04},
                {0x45, 0x00},
                {0x46, 0x59},
                {0x47, 0x00},
                {0x48, 0xf2},
                {0x49, 0x06},
                {0x4a, 0x00},
                {0x4b, 0x72},
                {0x4c, 0x45},
                {0x4d, 0x00},
                {0x52, 0x08},
                {0x53, 0x00},
                {0x54, 0xb2},
                {0x55, 0x00},
                {0x56, 0xe4},
                {0x57, 0x0d},
                {0x58, 0x00},
                {0x59, 0xe4},
                {0x5a, 0x8a},
                {0x5b, 0x00},
                {0x5c, 0x34},
                {0x1e, 0x4f},
                {0x51, 0x00},
        };

        return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
}

static int lt8912_write_rxlogicres_config(struct lt8912 *lt)
{
        int ret;

        ret = regmap_write(lt->regmap[I2C_MAIN], 0x03, 0x7f);
        usleep_range(10000, 20000);
        ret |= regmap_write(lt->regmap[I2C_MAIN], 0x03, 0xff);

        return ret;
};

/* enable LVDS output with some hardcoded configuration, not required for the HDMI output */
static int lt8912_write_lvds_config(struct lt8912 *lt)
{
        const struct reg_sequence seq[] = {
                // lvds power up
                {0x44, 0x30},
                {0x51, 0x05},

                // core pll bypass
                {0x50, 0x24}, // cp=50uA
                {0x51, 0x2d}, // Pix_clk as reference, second order passive LPF PLL
                {0x52, 0x04}, // loopdiv=0, use second-order PLL
                {0x69, 0x0e}, // CP_PRESET_DIV_RATIO
                {0x69, 0x8e},
                {0x6a, 0x00},
                {0x6c, 0xb8}, // RGD_CP_SOFT_K_EN,RGD_CP_SOFT_K[13:8]
                {0x6b, 0x51},

                {0x04, 0xfb}, // core pll reset
                {0x04, 0xff},

                // scaler bypass
                {0x7f, 0x00}, // disable scaler
                {0xa8, 0x13}, // 0x13: JEIDA, 0x33: VESA

                {0x02, 0xf7}, // lvds pll reset
                {0x02, 0xff},
                {0x03, 0xcf},
                {0x03, 0xff},
        };

        return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
};

static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
{
        return container_of(b, struct lt8912, bridge);
}

static inline struct lt8912 *connector_to_lt8912(struct drm_connector *c)
{
        return container_of(c, struct lt8912, connector);
}

static const struct regmap_config lt8912_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0xff,
};

static int lt8912_init_i2c(struct lt8912 *lt, struct i2c_client *client)
{
        unsigned int i;
        /*
         * At this time we only initialize 2 chips, but the lt8912 provides
         * a third interface for the audio over HDMI configuration.
         */
        struct i2c_board_info info[] = {
                { I2C_BOARD_INFO("lt8912p0", I2C_ADDR_MAIN), },
                { I2C_BOARD_INFO("lt8912p1", I2C_ADDR_CEC_DSI), },
        };

        if (!lt)
                return -ENODEV;

        for (i = 0; i < ARRAY_SIZE(info); i++) {
                if (i > 0) {
                        lt->i2c_client[i] = i2c_new_dummy_device(client->adapter,
                                                                 info[i].addr);
                        if (IS_ERR(lt->i2c_client[i]))
                                return PTR_ERR(lt->i2c_client[i]);
                }

                lt->regmap[i] = devm_regmap_init_i2c(lt->i2c_client[i],
                                                     &lt8912_regmap_config);
                if (IS_ERR(lt->regmap[i]))
                        return PTR_ERR(lt->regmap[i]);
        }
        return 0;
}

static int lt8912_free_i2c(struct lt8912 *lt)
{
        unsigned int i;

        for (i = 1; i < I2C_MAX_IDX; i++)
                i2c_unregister_device(lt->i2c_client[i]);

        return 0;
}

static int lt8912_hard_power_on(struct lt8912 *lt)
{
        int ret;

        ret = regulator_bulk_enable(ARRAY_SIZE(lt->supplies), lt->supplies);
        if (ret)
                return ret;

        gpiod_set_value_cansleep(lt->gp_reset, 0);
        msleep(20);

        return 0;
}

static void lt8912_hard_power_off(struct lt8912 *lt)
{
        gpiod_set_value_cansleep(lt->gp_reset, 1);
        msleep(20);

        regulator_bulk_disable(ARRAY_SIZE(lt->supplies), lt->supplies);

        lt->is_power_on = false;
}

static int lt8912_video_setup(struct lt8912 *lt)
{
        u32 hactive, h_total, hpw, hfp, hbp;
        u32 vactive, v_total, vpw, vfp, vbp;
        u8 settle = 0x08;
        int ret, hsync_activehigh, vsync_activehigh;

        if (!lt)
                return -EINVAL;

        hactive = lt->mode.hactive;
        hfp = lt->mode.hfront_porch;
        hpw = lt->mode.hsync_len;
        hbp = lt->mode.hback_porch;
        h_total = hactive + hfp + hpw + hbp;
        hsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_HSYNC_HIGH;

        vactive = lt->mode.vactive;
        vfp = lt->mode.vfront_porch;
        vpw = lt->mode.vsync_len;
        vbp = lt->mode.vback_porch;
        v_total = vactive + vfp + vpw + vbp;
        vsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_VSYNC_HIGH;

        if (vactive <= 600)
                settle = 0x04;
        else if (vactive == 1080)
                settle = 0x0a;

        ret = regmap_write(lt->regmap[I2C_CEC_DSI], 0x10, 0x01);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x11, settle);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x18, hpw);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x19, vpw);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1c, hactive & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1d, hactive >> 8);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x2f, 0x0c);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x34, h_total & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x35, h_total >> 8);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x36, v_total & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x37, v_total >> 8);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x38, vbp & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x39, vbp >> 8);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3a, vfp & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3b, vfp >> 8);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3c, hbp & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3d, hbp >> 8);

        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff);
        ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8);

        ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(0),
                                  vsync_activehigh ? BIT(0) : 0);
        ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1),
                                  hsync_activehigh ? BIT(1) : 0);
        ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xb2, BIT(0),
                                  lt->connector.display_info.is_hdmi ? BIT(0) : 0);

        return ret;
}

static int lt8912_soft_power_on(struct lt8912 *lt)
{
        if (!lt->is_power_on) {
                u32 lanes = lt->data_lanes;

                lt8912_write_init_config(lt);
                regmap_write(lt->regmap[I2C_CEC_DSI], 0x13, lanes & 3);

                lt8912_write_mipi_basic_config(lt);

                lt->is_power_on = true;
        }

        return 0;
}

static int lt8912_video_on(struct lt8912 *lt)
{
        int ret;

        ret = lt8912_video_setup(lt);
        if (ret < 0)
                goto end;

        ret = lt8912_write_dds_config(lt);
        if (ret < 0)
                goto end;

        ret = lt8912_write_rxlogicres_config(lt);
        if (ret < 0)
                goto end;

        ret = lt8912_write_lvds_config(lt);
        if (ret < 0)
                goto end;

end:
        return ret;
}

static enum drm_connector_status lt8912_check_cable_status(struct lt8912 *lt)
{
        int ret;
        unsigned int reg_val;

        ret = regmap_read(lt->regmap[I2C_MAIN], 0xC1, &reg_val);
        if (ret)
                return connector_status_unknown;

        if (reg_val & BIT(7))
                return connector_status_connected;

        return connector_status_disconnected;
}

static enum drm_connector_status
lt8912_connector_detect(struct drm_connector *connector, bool force)
{
        struct lt8912 *lt = connector_to_lt8912(connector);

        if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_DETECT)
                return drm_bridge_detect(lt->bridge.next_bridge, connector);

        return lt8912_check_cable_status(lt);
}

static const struct drm_connector_funcs lt8912_connector_funcs = {
        .detect = lt8912_connector_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = drm_connector_cleanup,
        .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 int lt8912_connector_get_modes(struct drm_connector *connector)
{
        const struct drm_edid *drm_edid;
        struct lt8912 *lt = connector_to_lt8912(connector);
        u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
        int ret, num;

        drm_edid = drm_bridge_edid_read(lt->bridge.next_bridge, connector);
        drm_edid_connector_update(connector, drm_edid);
        if (!drm_edid)
                return 0;

        num = drm_edid_connector_add_modes(connector);

        ret = drm_display_info_set_bus_formats(&connector->display_info,
                                               &bus_format, 1);
        if (ret < 0)
                num = 0;

        drm_edid_free(drm_edid);
        return num;
}

static const struct drm_connector_helper_funcs lt8912_connector_helper_funcs = {
        .get_modes = lt8912_connector_get_modes,
};

static void lt8912_bridge_mode_set(struct drm_bridge *bridge,
                                   const struct drm_display_mode *mode,
                                   const struct drm_display_mode *adj)
{
        struct lt8912 *lt = bridge_to_lt8912(bridge);

        drm_display_mode_to_videomode(adj, &lt->mode);
}

static void lt8912_bridge_enable(struct drm_bridge *bridge)
{
        struct lt8912 *lt = bridge_to_lt8912(bridge);

        lt8912_video_on(lt);
}

static int lt8912_attach_dsi(struct lt8912 *lt)
{
        struct device *dev = lt->dev;
        struct mipi_dsi_host *host;
        struct mipi_dsi_device *dsi;
        int ret = -1;
        const struct mipi_dsi_device_info info = { .type = "lt8912",
                                                   .channel = 0,
                                                   .node = NULL,
                                                 };

        host = of_find_mipi_dsi_host_by_node(lt->host_node);
        if (!host)
                return dev_err_probe(dev, -EPROBE_DEFER, "failed to find dsi host\n");

        dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
        if (IS_ERR(dsi)) {
                ret = PTR_ERR(dsi);
                dev_err(dev, "failed to create dsi device (%d)\n", ret);
                return ret;
        }

        lt->dsi = dsi;

        dsi->lanes = lt->data_lanes;
        dsi->format = MIPI_DSI_FMT_RGB888;

        dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
                          MIPI_DSI_MODE_LPM |
                          MIPI_DSI_MODE_VIDEO_NO_HFP |
                          MIPI_DSI_MODE_NO_EOT_PACKET;

        ret = devm_mipi_dsi_attach(dev, dsi);
        if (ret < 0) {
                dev_err(dev, "failed to attach dsi to host\n");
                return ret;
        }

        return 0;
}

static void lt8912_bridge_hpd_cb(void *data, enum drm_connector_status status)
{
        struct lt8912 *lt = data;

        if (lt->bridge.dev)
                drm_helper_hpd_irq_event(lt->bridge.dev);
}

static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
{
        int ret;
        struct lt8912 *lt = bridge_to_lt8912(bridge);
        struct drm_connector *connector = &lt->connector;

        if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_HPD) {
                drm_bridge_hpd_enable(lt->bridge.next_bridge, lt8912_bridge_hpd_cb, lt);
                connector->polled = DRM_CONNECTOR_POLL_HPD;
        } else {
                connector->polled = DRM_CONNECTOR_POLL_CONNECT |
                                    DRM_CONNECTOR_POLL_DISCONNECT;
        }

        ret = drm_connector_init(bridge->dev, connector,
                                 &lt8912_connector_funcs,
                                 lt->bridge.next_bridge->type);
        if (ret)
                goto exit;

        drm_connector_helper_add(connector, &lt8912_connector_helper_funcs);

        connector->dpms = DRM_MODE_DPMS_OFF;
        drm_connector_attach_encoder(connector, bridge->encoder);

exit:
        return ret;
}

static int lt8912_bridge_attach(struct drm_bridge *bridge,
                                struct drm_encoder *encoder,
                                enum drm_bridge_attach_flags flags)
{
        struct lt8912 *lt = bridge_to_lt8912(bridge);
        int ret;

        ret = drm_bridge_attach(encoder, lt->bridge.next_bridge, bridge,
                                DRM_BRIDGE_ATTACH_NO_CONNECTOR);
        if (ret < 0) {
                dev_err(lt->dev, "Failed to attach next bridge (%d)\n", ret);
                return ret;
        }

        if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
                ret = lt8912_bridge_connector_init(bridge);
                if (ret) {
                        dev_err(lt->dev, "Failed to init bridge ! (%d)\n", ret);
                        return ret;
                }
        }

        ret = lt8912_hard_power_on(lt);
        if (ret)
                return ret;

        ret = lt8912_soft_power_on(lt);
        if (ret)
                goto error;

        return 0;

error:
        lt8912_hard_power_off(lt);
        return ret;
}

static void lt8912_bridge_detach(struct drm_bridge *bridge)
{
        struct lt8912 *lt = bridge_to_lt8912(bridge);

        lt8912_hard_power_off(lt);

        if (lt->connector.dev && lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_HPD)
                drm_bridge_hpd_disable(lt->bridge.next_bridge);
}

static enum drm_mode_status
lt8912_bridge_mode_valid(struct drm_bridge *bridge,
                         const struct drm_display_info *info,
                         const struct drm_display_mode *mode)
{
        if (mode->clock > 150000)
                return MODE_CLOCK_HIGH;

        if (mode->hdisplay > 1920)
                return MODE_BAD_HVALUE;

        if (mode->vdisplay > 1080)
                return MODE_BAD_VVALUE;

        return MODE_OK;
}

static enum drm_connector_status
lt8912_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector)
{
        struct lt8912 *lt = bridge_to_lt8912(bridge);

        if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_DETECT)
                return drm_bridge_detect(lt->bridge.next_bridge, connector);

        return lt8912_check_cable_status(lt);
}

static const struct drm_edid *lt8912_bridge_edid_read(struct drm_bridge *bridge,
                                                      struct drm_connector *connector)
{
        struct lt8912 *lt = bridge_to_lt8912(bridge);

        /*
         * edid must be read through the ddc bus but it must be
         * given to the hdmi connector node.
         */
        if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_EDID)
                return drm_bridge_edid_read(lt->bridge.next_bridge, connector);

        dev_warn(lt->dev, "The connected bridge does not supports DRM_BRIDGE_OP_EDID\n");
        return NULL;
}

static const struct drm_bridge_funcs lt8912_bridge_funcs = {
        .attach = lt8912_bridge_attach,
        .detach = lt8912_bridge_detach,
        .mode_valid = lt8912_bridge_mode_valid,
        .mode_set = lt8912_bridge_mode_set,
        .enable = lt8912_bridge_enable,
        .detect = lt8912_bridge_detect,
        .edid_read = lt8912_bridge_edid_read,
};

static int lt8912_bridge_resume(struct device *dev)
{
        struct lt8912 *lt = dev_get_drvdata(dev);
        int ret;

        ret = lt8912_hard_power_on(lt);
        if (ret)
                return ret;

        ret = lt8912_soft_power_on(lt);
        if (ret)
                return ret;

        return lt8912_video_on(lt);
}

static int lt8912_bridge_suspend(struct device *dev)
{
        struct lt8912 *lt = dev_get_drvdata(dev);

        lt8912_hard_power_off(lt);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(lt8912_bridge_pm_ops, lt8912_bridge_suspend, lt8912_bridge_resume);

static int lt8912_get_regulators(struct lt8912 *lt)
{
        unsigned int i;
        const char * const supply_names[] = {
                "vdd", "vccmipirx", "vccsysclk", "vcclvdstx",
                "vcchdmitx", "vcclvdspll", "vcchdmipll"
        };

        for (i = 0; i < ARRAY_SIZE(lt->supplies); i++)
                lt->supplies[i].supply = supply_names[i];

        return devm_regulator_bulk_get(lt->dev, ARRAY_SIZE(lt->supplies),
                                       lt->supplies);
}

static int lt8912_parse_dt(struct lt8912 *lt)
{
        struct gpio_desc *gp_reset;
        struct device *dev = lt->dev;
        int ret;
        int data_lanes;
        struct device_node *port_node;

        gp_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(gp_reset)) {
                ret = PTR_ERR(gp_reset);
                if (ret != -EPROBE_DEFER)
                        dev_err(dev, "Failed to get reset gpio: %d\n", ret);
                return ret;
        }
        lt->gp_reset = gp_reset;

        data_lanes = drm_of_get_data_lanes_count_ep(dev->of_node, 0, -1, 1, 4);
        if (data_lanes < 0) {
                dev_err(lt->dev, "%s: Bad data-lanes property\n", __func__);
                return data_lanes;
        }

        lt->data_lanes = data_lanes;

        lt->host_node = of_graph_get_remote_node(dev->of_node, 0, -1);
        if (!lt->host_node) {
                dev_err(lt->dev, "%s: Failed to get remote port\n", __func__);
                return -ENODEV;
        }

        port_node = of_graph_get_remote_node(dev->of_node, 1, -1);
        if (!port_node) {
                dev_err(lt->dev, "%s: Failed to get connector port\n", __func__);
                ret = -ENODEV;
                goto err_free_host_node;
        }

        lt->bridge.next_bridge = of_drm_find_and_get_bridge(port_node);
        if (!lt->bridge.next_bridge) {
                ret = -EPROBE_DEFER;
                dev_err_probe(lt->dev, ret, "%s: Failed to get hdmi port\n", __func__);
                goto err_free_host_node;
        }

        if (!of_device_is_compatible(port_node, "hdmi-connector")) {
                dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
                ret = -EINVAL;
                goto err_free_host_node;
        }

        ret = lt8912_get_regulators(lt);
        if (ret)
                goto err_free_host_node;

        of_node_put(port_node);
        return 0;

err_free_host_node:
        of_node_put(port_node);
        of_node_put(lt->host_node);
        return ret;
}

static int lt8912_put_dt(struct lt8912 *lt)
{
        of_node_put(lt->host_node);
        return 0;
}

static int lt8912_probe(struct i2c_client *client)
{
        static struct lt8912 *lt;
        int ret = 0;
        struct device *dev = &client->dev;

        lt = devm_drm_bridge_alloc(dev, struct lt8912, bridge,
                                   &lt8912_bridge_funcs);
        if (IS_ERR(lt))
                return PTR_ERR(lt);

        lt->dev = dev;
        lt->i2c_client[0] = client;

        ret = lt8912_parse_dt(lt);
        if (ret)
                goto err_dt_parse;

        ret = lt8912_init_i2c(lt, client);
        if (ret)
                goto err_i2c;

        i2c_set_clientdata(client, lt);

        lt->bridge.of_node = dev->of_node;
        lt->bridge.ops = (DRM_BRIDGE_OP_EDID |
                          DRM_BRIDGE_OP_DETECT);

        drm_bridge_add(&lt->bridge);

        ret = lt8912_attach_dsi(lt);
        if (ret)
                goto err_attach;

        return 0;

err_attach:
        drm_bridge_remove(&lt->bridge);
        lt8912_free_i2c(lt);
err_i2c:
        lt8912_put_dt(lt);
err_dt_parse:
        return ret;
}

static void lt8912_remove(struct i2c_client *client)
{
        struct lt8912 *lt = i2c_get_clientdata(client);

        drm_bridge_remove(&lt->bridge);
        lt8912_free_i2c(lt);
        lt8912_put_dt(lt);
}

static const struct of_device_id lt8912_dt_match[] = {
        {.compatible = "lontium,lt8912b"},
        {}
};
MODULE_DEVICE_TABLE(of, lt8912_dt_match);

static const struct i2c_device_id lt8912_id[] = {
        { "lt8912" },
        {}
};
MODULE_DEVICE_TABLE(i2c, lt8912_id);

static struct i2c_driver lt8912_i2c_driver = {
        .driver = {
                .name = "lt8912",
                .of_match_table = lt8912_dt_match,
                .pm = pm_sleep_ptr(&lt8912_bridge_pm_ops),
        },
        .probe = lt8912_probe,
        .remove = lt8912_remove,
        .id_table = lt8912_id,
};
module_i2c_driver(lt8912_i2c_driver);

MODULE_AUTHOR("Adrien Grassein <adrien.grassein@gmail.com>");
MODULE_DESCRIPTION("lt8912 drm driver");
MODULE_LICENSE("GPL v2");