From 230f7f061036a99fc02d2cd7d20f66f7f0efae99 Mon Sep 17 00:00:00 2001
From: Wyon Bi <bivvy.bi@rock-chips.com>
Date: Fri, 27 Apr 2018 17:58:15 +0800
Subject: [PATCH] drm/bridge: Add support for Lontium LT8912

The Lontium LT8912 MIPI-DSI to LVDS and HDMI/MHL bridge features a
single-channel MIPI D-PHY receiver front-end configuration with 4 data
lanes per channel operating at 1.5Gbps per data lane and a maximum
input bandwidth of 6Gbps.

Change-Id: I7733ea5f33094151bb62e62406561cc0025cf900
Signed-off-by: Wyon Bi <bivvy.bi@rock-chips.com>
---
 .../display/bridge/lontium,lt8912.txt         |  41 ++
 .../devicetree/bindings/vendor-prefixes.txt   |   1 +
 drivers/gpu/drm/bridge/Kconfig                |   8 +
 drivers/gpu/drm/bridge/Makefile               |   1 +
 drivers/gpu/drm/bridge/lt8912.c               | 500 ++++++++++++++++++
 5 files changed, 551 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/lontium,lt8912.txt
 create mode 100644 drivers/gpu/drm/bridge/lt8912.c

diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt8912.txt b/Documentation/devicetree/bindings/display/bridge/lontium,lt8912.txt
new file mode 100644
index 000000000000..0d0378febadb
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt8912.txt
@@ -0,0 +1,41 @@
+Lontium LT8912 MIPI-DSI to LVDS and HDMI/MHL bridge bindings
+
+Required properties:
+ - compatible: "lontium,lt8912"
+ - reg: virtual channel id
+ - reset-gpios: a GPIO spec for the reset pin
+ - i2c-bus: phandle of an I2C controller used for register access
+ - display-timings : Refer to binding doc display-timing.txt for details
+
+Example:
+
+&dsi {
+	status = "okay";
+
+	lt8912@0 {
+		compatible = "lontium,lt8912";
+		reg = <0>;
+		reset-gpios = <&gpio0 RK_PA2 GPIO_ACTIVE_LOW>;
+		i2c-bus = <&i2c1>;
+
+		display-timings {
+			native-mode = <&timing0>;
+
+			timing0: timing0 {
+				clock-frequency = <74250000>;
+				hactive = <1280>;
+				vactive = <720>;
+				hfront-porch = <110>;
+				hsync-len = <40>;
+				hback-porch = <220>;
+				vfront-porch = <5>;
+				vsync-len = <5>;
+				vback-porch = <20>;
+				hsync-active = <0>;
+				vsync-active = <0>;
+				de-active = <0>;
+				pixelclk-active = <0>;
+			};
+		};
+	};
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 435c8993e63d..79435048f722 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -131,6 +131,7 @@ lenovo	Lenovo Group Ltd.
 lg	LG Corporation
 linaro	Linaro Limited
 linux	Linux-specific binding
+lontium	Lontium Semiconductor Corporation
 lsi	LSI Corp. (LSI Logic)
 lltc	Linear Technology Corporation
 marvell	Marvell Technology Group Ltd.
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index cefe2fa55aa2..b4537addaf39 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -40,6 +40,14 @@ config DRM_DUMB_VGA_DAC
 	help
 	  Support for RGB to VGA DAC based bridges
 
+config DRM_LONTIUM_LT8912
+	tristate "Lontium LT8912 MIPI-DSI to LVDS and HDMI/MHL bridge"
+	depends on OF
+	select DRM_KMS_HELPER
+	select REGMAP_I2C
+	help
+	  Lontium LT8912 MIPI-DSI to LVDS and HDMI/MHL bridge chip driver.
+
 source "drivers/gpu/drm/bridge/analogix/Kconfig"
 
 source "drivers/gpu/drm/bridge/synopsys/Kconfig"
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 5117061a4e0f..f8e1c05b4fe4 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -5,4 +5,5 @@ obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
 obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix/
 obj-$(CONFIG_DRM_RK1000) += rk1000.o
 obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
+obj-$(CONFIG_DRM_LONTIUM_LT8912) += lt8912.o
 obj-y += synopsys/
diff --git a/drivers/gpu/drm/bridge/lt8912.c b/drivers/gpu/drm/bridge/lt8912.c
new file mode 100644
index 000000000000..76a28625b2ce
--- /dev/null
+++ b/drivers/gpu/drm/bridge/lt8912.c
@@ -0,0 +1,500 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Rockchip Electronics Co. Ltd.
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_graph.h>
+#include <linux/regmap.h>
+#include <video/of_display_timing.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_of.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_mipi_dsi.h>
+
+struct lt8912 {
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+	struct drm_display_mode mode;
+	struct device *dev;
+	struct mipi_dsi_device *dsi;
+	struct regmap *regmap[3];
+	struct gpio_desc *reset_n;
+};
+
+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);
+}
+
+/* LT8912 MIPI to HDMI & LVDS REG setting - 20180115.txt */
+static void lt8912_init(struct lt8912 *lt8912)
+{
+	u8 lanes = lt8912->dsi->lanes;
+	const struct drm_display_mode *mode = &lt8912->mode;
+	u32 hactive, hfp, hsync, hbp, vfp, vsync, vbp, htotal, vtotal;
+	unsigned int version[2];
+
+	/* TODO: lvds output init */
+
+	hactive = mode->hdisplay;
+	hfp = mode->hsync_start - mode->hdisplay;
+	hsync = mode->hsync_end - mode->hsync_start;
+	hbp = mode->htotal - mode->hsync_end;
+	vfp = mode->vsync_start - mode->vdisplay;
+	vsync = mode->vsync_end - mode->vsync_start;
+	vbp = mode->vtotal - mode->vsync_end;
+	htotal = mode->htotal;
+	vtotal = mode->vtotal;
+
+	regmap_read(lt8912->regmap[0], 0x00, &version[0]);
+	regmap_read(lt8912->regmap[0], 0x01, &version[1]);
+
+	dev_info(lt8912->dev, "LT8912 ID: %02x, %02x\n",
+		 version[0], version[1]);
+
+	/* DigitalClockEn */
+	regmap_write(lt8912->regmap[0], 0x08, 0xff);
+	regmap_write(lt8912->regmap[0], 0x09, 0x81);
+	regmap_write(lt8912->regmap[0], 0x0a, 0xff);
+	regmap_write(lt8912->regmap[0], 0x0b, 0x64);
+	regmap_write(lt8912->regmap[0], 0x0c, 0xff);
+
+	regmap_write(lt8912->regmap[0], 0x44, 0x31);
+	regmap_write(lt8912->regmap[0], 0x51, 0x1f);
+
+	/* TxAnalog */
+	regmap_write(lt8912->regmap[0], 0x31, 0xa1);
+	regmap_write(lt8912->regmap[0], 0x32, 0xa1);
+	regmap_write(lt8912->regmap[0], 0x33, 0x03);
+	regmap_write(lt8912->regmap[0], 0x37, 0x00);
+	regmap_write(lt8912->regmap[0], 0x38, 0x22);
+	regmap_write(lt8912->regmap[0], 0x60, 0x82);
+
+	/* CbusAnalog */
+	regmap_write(lt8912->regmap[0], 0x39, 0x45);
+	regmap_write(lt8912->regmap[0], 0x3b, 0x00);
+
+	/* HDMIPllAnalog */
+	regmap_write(lt8912->regmap[0], 0x44, 0x31);
+	regmap_write(lt8912->regmap[0], 0x55, 0x44);
+	regmap_write(lt8912->regmap[0], 0x57, 0x01);
+	regmap_write(lt8912->regmap[0], 0x5a, 0x02);
+
+	/* MipiBasicSet */
+	regmap_write(lt8912->regmap[1], 0x10, 0x01);
+	regmap_write(lt8912->regmap[1], 0x11, 0x08);
+	regmap_write(lt8912->regmap[1], 0x12, 0x04);
+	regmap_write(lt8912->regmap[1], 0x13, lanes % 4);
+	regmap_write(lt8912->regmap[1], 0x14, 0x00);
+
+	regmap_write(lt8912->regmap[1], 0x15, 0x00);
+	regmap_write(lt8912->regmap[1], 0x1a, 0x03);
+	regmap_write(lt8912->regmap[1], 0x1b, 0x03);
+
+	/* MIPIDig */
+	regmap_write(lt8912->regmap[1], 0x18, hsync);
+	regmap_write(lt8912->regmap[1], 0x19, vsync);
+	regmap_write(lt8912->regmap[1], 0x1c, hactive);
+	regmap_write(lt8912->regmap[1], 0x1d, hactive >> 8);
+
+	regmap_write(lt8912->regmap[1], 0x1e, 0x67);
+	regmap_write(lt8912->regmap[1], 0x2f, 0x0c);
+
+	regmap_write(lt8912->regmap[1], 0x34, htotal);
+	regmap_write(lt8912->regmap[1], 0x35, htotal >> 8);
+	regmap_write(lt8912->regmap[1], 0x36, vtotal);
+	regmap_write(lt8912->regmap[1], 0x37, vtotal >> 8);
+	regmap_write(lt8912->regmap[1], 0x38, vbp);
+	regmap_write(lt8912->regmap[1], 0x39, vbp >> 8);
+	regmap_write(lt8912->regmap[1], 0x3a, vfp);
+	regmap_write(lt8912->regmap[1], 0x3b, vfp >> 8);
+	regmap_write(lt8912->regmap[1], 0x3c, hbp);
+	regmap_write(lt8912->regmap[1], 0x3d, hbp >> 8);
+	regmap_write(lt8912->regmap[1], 0x3e, hfp);
+	regmap_write(lt8912->regmap[1], 0x3f, hfp >> 8);
+
+	/* DDSConfig */
+	regmap_write(lt8912->regmap[1], 0x4e, 0x52);
+	regmap_write(lt8912->regmap[1], 0x4f, 0xde);
+	regmap_write(lt8912->regmap[1], 0x50, 0xc0);
+	regmap_write(lt8912->regmap[1], 0x51, 0x80);
+	regmap_write(lt8912->regmap[1], 0x51, 0x00);
+
+	regmap_write(lt8912->regmap[1], 0x1f, 0x5e);
+	regmap_write(lt8912->regmap[1], 0x20, 0x01);
+	regmap_write(lt8912->regmap[1], 0x21, 0x2c);
+	regmap_write(lt8912->regmap[1], 0x22, 0x01);
+	regmap_write(lt8912->regmap[1], 0x23, 0xfa);
+	regmap_write(lt8912->regmap[1], 0x24, 0x00);
+	regmap_write(lt8912->regmap[1], 0x25, 0xc8);
+	regmap_write(lt8912->regmap[1], 0x26, 0x00);
+	regmap_write(lt8912->regmap[1], 0x27, 0x5e);
+	regmap_write(lt8912->regmap[1], 0x28, 0x01);
+	regmap_write(lt8912->regmap[1], 0x29, 0x2c);
+	regmap_write(lt8912->regmap[1], 0x2a, 0x01);
+	regmap_write(lt8912->regmap[1], 0x2b, 0xfa);
+	regmap_write(lt8912->regmap[1], 0x2c, 0x00);
+	regmap_write(lt8912->regmap[1], 0x2d, 0xc8);
+	regmap_write(lt8912->regmap[1], 0x2e, 0x00);
+
+	regmap_write(lt8912->regmap[0], 0x03, 0x7f);
+	usleep_range(10000, 20000);
+	regmap_write(lt8912->regmap[0], 0x03, 0xff);
+
+	regmap_write(lt8912->regmap[1], 0x42, 0x64);
+	regmap_write(lt8912->regmap[1], 0x43, 0x00);
+	regmap_write(lt8912->regmap[1], 0x44, 0x04);
+	regmap_write(lt8912->regmap[1], 0x45, 0x00);
+	regmap_write(lt8912->regmap[1], 0x46, 0x59);
+	regmap_write(lt8912->regmap[1], 0x47, 0x00);
+	regmap_write(lt8912->regmap[1], 0x48, 0xf2);
+	regmap_write(lt8912->regmap[1], 0x49, 0x06);
+	regmap_write(lt8912->regmap[1], 0x4a, 0x00);
+	regmap_write(lt8912->regmap[1], 0x4b, 0x72);
+	regmap_write(lt8912->regmap[1], 0x4c, 0x45);
+	regmap_write(lt8912->regmap[1], 0x4d, 0x00);
+	regmap_write(lt8912->regmap[1], 0x52, 0x08);
+	regmap_write(lt8912->regmap[1], 0x53, 0x00);
+	regmap_write(lt8912->regmap[1], 0x54, 0xb2);
+	regmap_write(lt8912->regmap[1], 0x55, 0x00);
+	regmap_write(lt8912->regmap[1], 0x56, 0xe4);
+	regmap_write(lt8912->regmap[1], 0x57, 0x0d);
+	regmap_write(lt8912->regmap[1], 0x58, 0x00);
+	regmap_write(lt8912->regmap[1], 0x59, 0xe4);
+	regmap_write(lt8912->regmap[1], 0x5a, 0x8a);
+	regmap_write(lt8912->regmap[1], 0x5b, 0x00);
+	regmap_write(lt8912->regmap[1], 0x5c, 0x34);
+	regmap_write(lt8912->regmap[1], 0x1e, 0x4f);
+	regmap_write(lt8912->regmap[1], 0x51, 0x00);
+
+	regmap_write(lt8912->regmap[0], 0xb2, 0x01);
+
+	/* AudioIIsEn */
+	regmap_write(lt8912->regmap[2], 0x06, 0x08);
+	regmap_write(lt8912->regmap[2], 0x07, 0xf0);
+
+	regmap_write(lt8912->regmap[2], 0x34, 0xd2);
+
+	regmap_write(lt8912->regmap[2], 0x3c, 0x41);
+
+	/* MIPIRxLogicRes */
+	regmap_write(lt8912->regmap[0], 0x03, 0x7f);
+	usleep_range(10000, 20000);
+	regmap_write(lt8912->regmap[0], 0x03, 0xff);
+
+	regmap_write(lt8912->regmap[1], 0x51, 0x80);
+	usleep_range(10000, 20000);
+	regmap_write(lt8912->regmap[1], 0x51, 0x00);
+}
+
+static void lt8912_exit(struct lt8912 *lt8912)
+{
+	regmap_write(lt8912->regmap[0], 0x08, 0x00);
+	regmap_write(lt8912->regmap[0], 0x09, 0x81);
+	regmap_write(lt8912->regmap[0], 0x0a, 0x00);
+	regmap_write(lt8912->regmap[0], 0x0b, 0x20);
+	regmap_write(lt8912->regmap[0], 0x0c, 0x00);
+
+	regmap_write(lt8912->regmap[0], 0x54, 0x1d);
+	regmap_write(lt8912->regmap[0], 0x51, 0x15);
+
+	regmap_write(lt8912->regmap[0], 0x44, 0x31);
+	regmap_write(lt8912->regmap[0], 0x41, 0xbd);
+	regmap_write(lt8912->regmap[0], 0x5c, 0x11);
+
+	regmap_write(lt8912->regmap[0], 0x30, 0x08);
+	regmap_write(lt8912->regmap[0], 0x31, 0x00);
+	regmap_write(lt8912->regmap[0], 0x32, 0x00);
+	regmap_write(lt8912->regmap[0], 0x33, 0x00);
+	regmap_write(lt8912->regmap[0], 0x34, 0x00);
+	regmap_write(lt8912->regmap[0], 0x35, 0x00);
+	regmap_write(lt8912->regmap[0], 0x36, 0x00);
+	regmap_write(lt8912->regmap[0], 0x37, 0x00);
+	regmap_write(lt8912->regmap[0], 0x38, 0x00);
+}
+
+static void lt8912_power_on(struct lt8912 *lt8912)
+{
+	gpiod_direction_output(lt8912->reset_n, 1);
+	msleep(120);
+	gpiod_direction_output(lt8912->reset_n, 0);
+}
+
+static void lt8912_power_off(struct lt8912 *lt8912)
+{
+	gpiod_direction_output(lt8912->reset_n, 1);
+}
+
+static enum drm_connector_status
+lt8912_connector_detect(struct drm_connector *connector, bool force)
+{
+	/* TODO: HPD handing (reg[0xc1] - bit[7]) */
+	return connector_status_connected;
+}
+
+static const struct drm_connector_funcs lt8912_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.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 struct drm_encoder *
+lt8912_connector_best_encoder(struct drm_connector *connector)
+{
+	struct lt8912 *lt8912 = connector_to_lt8912(connector);
+
+	return lt8912->bridge.encoder;
+}
+
+static int lt8912_connector_get_modes(struct drm_connector *connector)
+{
+	struct lt8912 *lt8912 = connector_to_lt8912(connector);
+	struct drm_display_mode *mode;
+	int ret;
+
+	/* TODO: EDID handing */
+
+	mode = drm_mode_create(connector->dev);
+	if (!mode)
+		return -EINVAL;
+
+	ret = of_get_drm_display_mode(lt8912->dev->of_node, mode,
+				      OF_USE_NATIVE_MODE);
+	if (ret) {
+		dev_err(lt8912->dev, "failed to get display timings\n");
+		drm_mode_destroy(connector->dev, mode);
+		return 0;
+	}
+
+	mode->type |= DRM_MODE_TYPE_PREFERRED;
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_connector_helper_funcs lt8912_connector_helper_funcs = {
+	.get_modes = lt8912_connector_get_modes,
+	.best_encoder = lt8912_connector_best_encoder,
+};
+
+static void lt8912_bridge_post_disable(struct drm_bridge *bridge)
+{
+	struct lt8912 *lt8912 = bridge_to_lt8912(bridge);
+
+	lt8912_power_off(lt8912);
+}
+
+static void lt8912_bridge_disable(struct drm_bridge *bridge)
+{
+	struct lt8912 *lt8912 = bridge_to_lt8912(bridge);
+
+	lt8912_exit(lt8912);
+}
+
+static void lt8912_bridge_enable(struct drm_bridge *bridge)
+{
+	struct lt8912 *lt8912 = bridge_to_lt8912(bridge);
+
+	lt8912_init(lt8912);
+}
+
+static void lt8912_bridge_pre_enable(struct drm_bridge *bridge)
+{
+	struct lt8912 *lt8912 = bridge_to_lt8912(bridge);
+
+	lt8912_power_on(lt8912);
+}
+
+static void lt8912_bridge_mode_set(struct drm_bridge *bridge,
+				   struct drm_display_mode *mode,
+				   struct drm_display_mode *adj)
+{
+	struct lt8912 *lt8912 = bridge_to_lt8912(bridge);
+
+	drm_mode_copy(&lt8912->mode, adj);
+}
+
+static int lt8912_bridge_attach(struct drm_bridge *bridge)
+{
+	struct lt8912 *lt8912 = bridge_to_lt8912(bridge);
+	struct drm_connector *connector = &lt8912->connector;
+	int ret;
+
+	ret = drm_connector_init(bridge->dev, connector,
+				 &lt8912_connector_funcs,
+				 DRM_MODE_CONNECTOR_HDMIA);
+	if (ret) {
+		dev_err(lt8912->dev, "failed to initialize connector\n");
+		return ret;
+	}
+
+	drm_connector_helper_add(connector, &lt8912_connector_helper_funcs);
+	drm_mode_connector_attach_encoder(connector, bridge->encoder);
+
+	return 0;
+}
+
+static const struct drm_bridge_funcs lt8912_bridge_funcs = {
+	.attach = lt8912_bridge_attach,
+	.mode_set = lt8912_bridge_mode_set,
+	.pre_enable = lt8912_bridge_pre_enable,
+	.enable = lt8912_bridge_enable,
+	.disable = lt8912_bridge_disable,
+	.post_disable = lt8912_bridge_post_disable,
+};
+
+static const struct regmap_config lt8912_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+};
+
+static int lt8912_i2c_init(struct lt8912 *lt8912,
+			   struct i2c_adapter *adapter)
+{
+	struct i2c_board_info info[] = {
+		{ I2C_BOARD_INFO("lt8912p0", 0x48), },
+		{ I2C_BOARD_INFO("lt8912p1", 0x49), },
+		{ I2C_BOARD_INFO("lt8912p2", 0x4a), }
+	};
+	struct regmap *regmap;
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(info); i++) {
+		struct i2c_client *client;
+
+		client = i2c_new_device(adapter, &info[i]);
+		if (!client)
+			return -ENODEV;
+
+		regmap = devm_regmap_init_i2c(client, &lt8912_regmap_config);
+		if (IS_ERR(regmap)) {
+			ret = PTR_ERR(regmap);
+			dev_err(lt8912->dev,
+				"Failed to initialize regmap: %d\n", ret);
+			return ret;
+		}
+
+		lt8912->regmap[i] = regmap;
+	}
+
+	return 0;
+}
+
+static int lt8912_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct lt8912 *lt8912;
+	struct device_node *node;
+	struct i2c_adapter *adapter;
+	int ret;
+
+	lt8912 = devm_kzalloc(dev, sizeof(*lt8912), GFP_KERNEL);
+	if (!lt8912)
+		return -ENOMEM;
+
+	lt8912->dev = dev;
+	lt8912->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, lt8912);
+
+	lt8912->reset_n = devm_gpiod_get(dev, "reset", GPIOD_ASIS);
+	if (IS_ERR(lt8912->reset_n)) {
+		ret = PTR_ERR(lt8912->reset_n);
+		dev_err(dev, "failed to request reset GPIO: %d\n", ret);
+		return ret;
+	}
+
+	node = of_parse_phandle(dev->of_node, "i2c-bus", 0);
+	if (!node) {
+		dev_err(dev, "No i2c-bus found\n");
+		return -ENODEV;
+	}
+
+	adapter = of_find_i2c_adapter_by_node(node);
+	of_node_put(node);
+	if (!adapter) {
+		dev_err(dev, "No i2c adapter found\n");
+		return -EPROBE_DEFER;
+	}
+
+	ret = lt8912_i2c_init(lt8912, adapter);
+	if (ret)
+		return ret;
+
+	/* TODO: interrupt handing */
+
+	lt8912->bridge.funcs = &lt8912_bridge_funcs;
+	lt8912->bridge.of_node = dev->of_node;
+	ret = drm_bridge_add(&lt8912->bridge);
+	if (ret) {
+		dev_err(dev, "failed to add bridge: %d\n", ret);
+		return ret;
+	}
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET;
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret) {
+		drm_bridge_remove(&lt8912->bridge);
+		dev_err(dev, "failed to attach dsi to host: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int lt8912_remove(struct mipi_dsi_device *dsi)
+{
+	struct lt8912 *lt8912 = mipi_dsi_get_drvdata(dsi);
+
+	mipi_dsi_detach(dsi);
+	drm_bridge_remove(&lt8912->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id lt8912_of_match[] = {
+	{ .compatible = "lontium,lt8912" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, lt8912_of_match);
+
+static struct mipi_dsi_driver lt8912_driver = {
+	.driver = {
+		.name = "lt8912",
+		.of_match_table = lt8912_of_match,
+	},
+	.probe = lt8912_probe,
+	.remove = lt8912_remove,
+};
+module_mipi_dsi_driver(lt8912_driver);
+
+MODULE_AUTHOR("Wyon Bi <bivvy.bi@rock-chips.com>");
+MODULE_DESCRIPTION("Lontium LT8912 MIPI-DSI to LVDS and HDMI/MHL bridge");
+MODULE_LICENSE("GPL v2");