drm: bridge: add it66121 driver

This commit is a simple driver for bridge HMDI it66121.
The input format is RBG and there is no color conversion.
Audio, HDCP and CEC are not supported yet.

Signed-off-by: Phong LE <ple@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210419071223.2673533-3-narmstrong@baylibre.com

3 files changed, 1030 insertions, 0 deletions

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 70402da5cc70..d907a91a2ee8 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -101,6 +101,14 @@ config DRM_LONTIUM_LT9611UXC
 	  HDMI signals
 	  Please say Y if you have such hardware.
 
+config DRM_ITE_IT66121
+	tristate "ITE IT66121 HDMI bridge"
+	depends on OF
+	select DRM_KMS_HELPER
+	select REGMAP_I2C
+	help
+	  Support for ITE IT66121 HDMI bridge.
+
 config DRM_LVDS_CODEC
 	tristate "Transparent LVDS encoders and decoders support"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 5c61b50c1663..965b54dccfe5 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
 obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
 obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
 obj-$(CONFIG_DRM_NWL_MIPI_DSI) += nwl-dsi.o
+obj-$(CONFIG_DRM_ITE_IT66121) += ite-it66121.o
 
 obj-y += analogix/
 obj-y += cadence/
diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
new file mode 100644
index 000000000000..d8a60691fd32
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -0,0 +1,1021 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 BayLibre, SAS
+ * Author: Phong LE <ple@baylibre.com>
+ * Copyright (C) 2018-2019, Artem Mygaiev
+ * Copyright (C) 2017, Fresco Logic, Incorporated.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/bitfield.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/of_graph.h>
+#include <linux/gpio/consumer.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+#define IT66121_VENDOR_ID0_REG			0x00
+#define IT66121_VENDOR_ID1_REG			0x01
+#define IT66121_DEVICE_ID0_REG			0x02
+#define IT66121_DEVICE_ID1_REG			0x03
+
+#define IT66121_VENDOR_ID0			0x54
+#define IT66121_VENDOR_ID1			0x49
+#define IT66121_DEVICE_ID0			0x12
+#define IT66121_DEVICE_ID1			0x06
+#define IT66121_REVISION_MASK			GENMASK(7, 4)
+#define IT66121_DEVICE_ID1_MASK			GENMASK(3, 0)
+
+#define IT66121_MASTER_SEL_REG			0x10
+#define IT66121_MASTER_SEL_HOST			BIT(0)
+
+#define IT66121_AFE_DRV_REG			0x61
+#define IT66121_AFE_DRV_RST			BIT(4)
+#define IT66121_AFE_DRV_PWD			BIT(5)
+
+#define IT66121_INPUT_MODE_REG			0x70
+#define IT66121_INPUT_MODE_RGB			(0 << 6)
+#define IT66121_INPUT_MODE_YUV422		BIT(6)
+#define IT66121_INPUT_MODE_YUV444		(2 << 6)
+#define IT66121_INPUT_MODE_CCIR656		BIT(4)
+#define IT66121_INPUT_MODE_SYNCEMB		BIT(3)
+#define IT66121_INPUT_MODE_DDR			BIT(2)
+
+#define IT66121_INPUT_CSC_REG			0x72
+#define IT66121_INPUT_CSC_ENDITHER		BIT(7)
+#define IT66121_INPUT_CSC_ENUDFILTER		BIT(6)
+#define IT66121_INPUT_CSC_DNFREE_GO		BIT(5)
+#define IT66121_INPUT_CSC_RGB_TO_YUV		0x02
+#define IT66121_INPUT_CSC_YUV_TO_RGB		0x03
+#define IT66121_INPUT_CSC_NO_CONV		0x00
+
+#define IT66121_AFE_XP_REG			0x62
+#define IT66121_AFE_XP_GAINBIT			BIT(7)
+#define IT66121_AFE_XP_PWDPLL			BIT(6)
+#define IT66121_AFE_XP_ENI			BIT(5)
+#define IT66121_AFE_XP_ENO			BIT(4)
+#define IT66121_AFE_XP_RESETB			BIT(3)
+#define IT66121_AFE_XP_PWDI			BIT(2)
+
+#define IT66121_AFE_IP_REG			0x64
+#define IT66121_AFE_IP_GAINBIT			BIT(7)
+#define IT66121_AFE_IP_PWDPLL			BIT(6)
+#define IT66121_AFE_IP_CKSEL_05			(0 << 4)
+#define IT66121_AFE_IP_CKSEL_1			BIT(4)
+#define IT66121_AFE_IP_CKSEL_2			(2 << 4)
+#define IT66121_AFE_IP_CKSEL_2OR4		(3 << 4)
+#define IT66121_AFE_IP_ER0			BIT(3)
+#define IT66121_AFE_IP_RESETB			BIT(2)
+#define IT66121_AFE_IP_ENC			BIT(1)
+#define IT66121_AFE_IP_EC1			BIT(0)
+
+#define IT66121_AFE_XP_EC1_REG			0x68
+#define IT66121_AFE_XP_EC1_LOWCLK		BIT(4)
+
+#define IT66121_SW_RST_REG			0x04
+#define IT66121_SW_RST_REF			BIT(5)
+#define IT66121_SW_RST_AREF			BIT(4)
+#define IT66121_SW_RST_VID			BIT(3)
+#define IT66121_SW_RST_AUD			BIT(2)
+#define IT66121_SW_RST_HDCP			BIT(0)
+
+#define IT66121_DDC_COMMAND_REG			0x15
+#define IT66121_DDC_COMMAND_BURST_READ		0x0
+#define IT66121_DDC_COMMAND_EDID_READ		0x3
+#define IT66121_DDC_COMMAND_FIFO_CLR		0x9
+#define IT66121_DDC_COMMAND_SCL_PULSE		0xA
+#define IT66121_DDC_COMMAND_ABORT		0xF
+
+#define IT66121_HDCP_REG			0x20
+#define IT66121_HDCP_CPDESIRED			BIT(0)
+#define IT66121_HDCP_EN1P1FEAT			BIT(1)
+
+#define IT66121_INT_STATUS1_REG			0x06
+#define IT66121_INT_STATUS1_AUD_OVF		BIT(7)
+#define IT66121_INT_STATUS1_DDC_NOACK		BIT(5)
+#define IT66121_INT_STATUS1_DDC_FIFOERR		BIT(4)
+#define IT66121_INT_STATUS1_DDC_BUSHANG		BIT(2)
+#define IT66121_INT_STATUS1_RX_SENS_STATUS	BIT(1)
+#define IT66121_INT_STATUS1_HPD_STATUS		BIT(0)
+
+#define IT66121_DDC_HEADER_REG			0x11
+#define IT66121_DDC_HEADER_HDCP			0x74
+#define IT66121_DDC_HEADER_EDID			0xA0
+
+#define IT66121_DDC_OFFSET_REG			0x12
+#define IT66121_DDC_BYTE_REG			0x13
+#define IT66121_DDC_SEGMENT_REG			0x14
+#define IT66121_DDC_RD_FIFO_REG			0x17
+
+#define IT66121_CLK_BANK_REG			0x0F
+#define IT66121_CLK_BANK_PWROFF_RCLK		BIT(6)
+#define IT66121_CLK_BANK_PWROFF_ACLK		BIT(5)
+#define IT66121_CLK_BANK_PWROFF_TXCLK		BIT(4)
+#define IT66121_CLK_BANK_PWROFF_CRCLK		BIT(3)
+#define IT66121_CLK_BANK_0			0
+#define IT66121_CLK_BANK_1			1
+
+#define IT66121_INT_REG				0x05
+#define IT66121_INT_ACTIVE_HIGH			BIT(7)
+#define IT66121_INT_OPEN_DRAIN			BIT(6)
+#define IT66121_INT_TX_CLK_OFF			BIT(0)
+
+#define IT66121_INT_MASK1_REG			0x09
+#define IT66121_INT_MASK1_AUD_OVF		BIT(7)
+#define IT66121_INT_MASK1_DDC_NOACK		BIT(5)
+#define IT66121_INT_MASK1_DDC_FIFOERR		BIT(4)
+#define IT66121_INT_MASK1_DDC_BUSHANG		BIT(2)
+#define IT66121_INT_MASK1_RX_SENS		BIT(1)
+#define IT66121_INT_MASK1_HPD			BIT(0)
+
+#define IT66121_INT_CLR1_REG			0x0C
+#define IT66121_INT_CLR1_PKTACP			BIT(7)
+#define IT66121_INT_CLR1_PKTNULL		BIT(6)
+#define IT66121_INT_CLR1_PKTGEN			BIT(5)
+#define IT66121_INT_CLR1_KSVLISTCHK		BIT(4)
+#define IT66121_INT_CLR1_AUTHDONE		BIT(3)
+#define IT66121_INT_CLR1_AUTHFAIL		BIT(2)
+#define IT66121_INT_CLR1_RX_SENS		BIT(1)
+#define IT66121_INT_CLR1_HPD			BIT(0)
+
+#define IT66121_AV_MUTE_REG			0xC1
+#define IT66121_AV_MUTE_ON			BIT(0)
+#define IT66121_AV_MUTE_BLUESCR			BIT(1)
+
+#define IT66121_PKT_GEN_CTRL_REG		0xC6
+#define IT66121_PKT_GEN_CTRL_ON			BIT(0)
+#define IT66121_PKT_GEN_CTRL_RPT		BIT(1)
+
+#define IT66121_AVIINFO_DB1_REG			0x158
+#define IT66121_AVIINFO_DB2_REG			0x159
+#define IT66121_AVIINFO_DB3_REG			0x15A
+#define IT66121_AVIINFO_DB4_REG			0x15B
+#define IT66121_AVIINFO_DB5_REG			0x15C
+#define IT66121_AVIINFO_CSUM_REG		0x15D
+#define IT66121_AVIINFO_DB6_REG			0x15E
+#define IT66121_AVIINFO_DB7_REG			0x15F
+#define IT66121_AVIINFO_DB8_REG			0x160
+#define IT66121_AVIINFO_DB9_REG			0x161
+#define IT66121_AVIINFO_DB10_REG		0x162
+#define IT66121_AVIINFO_DB11_REG		0x163
+#define IT66121_AVIINFO_DB12_REG		0x164
+#define IT66121_AVIINFO_DB13_REG		0x165
+
+#define IT66121_AVI_INFO_PKT_REG		0xCD
+#define IT66121_AVI_INFO_PKT_ON			BIT(0)
+#define IT66121_AVI_INFO_PKT_RPT		BIT(1)
+
+#define IT66121_HDMI_MODE_REG			0xC0
+#define IT66121_HDMI_MODE_HDMI			BIT(0)
+
+#define IT66121_SYS_STATUS_REG			0x0E
+#define IT66121_SYS_STATUS_ACTIVE_IRQ		BIT(7)
+#define IT66121_SYS_STATUS_HPDETECT		BIT(6)
+#define IT66121_SYS_STATUS_SENDECTECT		BIT(5)
+#define IT66121_SYS_STATUS_VID_STABLE		BIT(4)
+#define IT66121_SYS_STATUS_AUD_CTS_CLR		BIT(1)
+#define IT66121_SYS_STATUS_CLEAR_IRQ		BIT(0)
+
+#define IT66121_DDC_STATUS_REG			0x16
+#define IT66121_DDC_STATUS_TX_DONE		BIT(7)
+#define IT66121_DDC_STATUS_ACTIVE		BIT(6)
+#define IT66121_DDC_STATUS_NOACK		BIT(5)
+#define IT66121_DDC_STATUS_WAIT_BUS		BIT(4)
+#define IT66121_DDC_STATUS_ARBI_LOSE		BIT(3)
+#define IT66121_DDC_STATUS_FIFO_FULL		BIT(2)
+#define IT66121_DDC_STATUS_FIFO_EMPTY		BIT(1)
+#define IT66121_DDC_STATUS_FIFO_VALID		BIT(0)
+
+#define IT66121_EDID_SLEEP_US			20000
+#define IT66121_EDID_TIMEOUT_US			200000
+#define IT66121_EDID_FIFO_SIZE			32
+#define IT66121_AFE_CLK_HIGH			80000 /* Khz */
+
+struct it66121_ctx {
+	struct regmap *regmap;
+	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
+	struct drm_connector *connector;
+	struct device *dev;
+	struct gpio_desc *gpio_reset;
+	struct i2c_client *client;
+	struct regulator_bulk_data supplies[3];
+	u32 bus_width;
+	struct mutex lock; /* Protects fields below and device registers */
+	struct hdmi_avi_infoframe hdmi_avi_infoframe;
+};
+
+static const struct regmap_range_cfg it66121_regmap_banks[] = {
+	{
+		.name = "it66121",
+		.range_min = 0x00,
+		.range_max = 0x1FF,
+		.selector_reg = IT66121_CLK_BANK_REG,
+		.selector_mask = 0x1,
+		.selector_shift = 0,
+		.window_start = 0x00,
+		.window_len = 0x130,
+	},
+};
+
+static const struct regmap_config it66121_regmap_config = {
+	.val_bits = 8,
+	.reg_bits = 8,
+	.max_register = 0x1FF,
+	.ranges = it66121_regmap_banks,
+	.num_ranges = ARRAY_SIZE(it66121_regmap_banks),
+};
+
+static void it66121_hw_reset(struct it66121_ctx *ctx)
+{
+	gpiod_set_value(ctx->gpio_reset, 1);
+	msleep(20);
+	gpiod_set_value(ctx->gpio_reset, 0);
+}
+
+static inline int ite66121_power_on(struct it66121_ctx *ctx)
+{
+	return regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+}
+
+static inline int ite66121_power_off(struct it66121_ctx *ctx)
+{
+	return regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+}
+
+static inline int it66121_preamble_ddc(struct it66121_ctx *ctx)
+{
+	return regmap_write(ctx->regmap, IT66121_MASTER_SEL_REG, IT66121_MASTER_SEL_HOST);
+}
+
+static inline int it66121_fire_afe(struct it66121_ctx *ctx)
+{
+	return regmap_write(ctx->regmap, IT66121_AFE_DRV_REG, 0);
+}
+
+/* TOFIX: Handle YCbCr Input & Output */
+static int it66121_configure_input(struct it66121_ctx *ctx)
+{
+	int ret;
+	u8 mode = IT66121_INPUT_MODE_RGB;
+
+	if (ctx->bus_width == 12)
+		mode |= IT66121_INPUT_MODE_DDR;
+
+	ret = regmap_write(ctx->regmap, IT66121_INPUT_MODE_REG, mode);
+	if (ret)
+		return ret;
+
+	return regmap_write(ctx->regmap, IT66121_INPUT_CSC_REG, IT66121_INPUT_CSC_NO_CONV);
+}
+
+/**
+ * it66121_configure_afe() - Configure the analog front end
+ * @ctx: it66121_ctx object
+ * @mode: mode to configure
+ *
+ * RETURNS:
+ * zero if success, a negative error code otherwise.
+ */
+static int it66121_configure_afe(struct it66121_ctx *ctx,
+				 const struct drm_display_mode *mode)
+{
+	int ret;
+
+	ret = regmap_write(ctx->regmap, IT66121_AFE_DRV_REG,
+			   IT66121_AFE_DRV_RST);
+	if (ret)
+		return ret;
+
+	if (mode->clock > IT66121_AFE_CLK_HIGH) {
+		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_REG,
+					IT66121_AFE_XP_GAINBIT |
+					IT66121_AFE_XP_ENO,
+					IT66121_AFE_XP_GAINBIT);
+		if (ret)
+			return ret;
+
+		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
+					IT66121_AFE_IP_GAINBIT |
+					IT66121_AFE_IP_ER0 |
+					IT66121_AFE_IP_EC1,
+					IT66121_AFE_IP_GAINBIT);
+		if (ret)
+			return ret;
+
+		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_EC1_REG,
+					IT66121_AFE_XP_EC1_LOWCLK, 0x80);
+		if (ret)
+			return ret;
+	} else {
+		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_REG,
+					IT66121_AFE_XP_GAINBIT |
+					IT66121_AFE_XP_ENO,
+					IT66121_AFE_XP_ENO);
+		if (ret)
+			return ret;
+
+		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
+					IT66121_AFE_IP_GAINBIT |
+					IT66121_AFE_IP_ER0 |
+					IT66121_AFE_IP_EC1, IT66121_AFE_IP_ER0 |
+					IT66121_AFE_IP_EC1);
+		if (ret)
+			return ret;
+
+		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_EC1_REG,
+					IT66121_AFE_XP_EC1_LOWCLK,
+					IT66121_AFE_XP_EC1_LOWCLK);
+		if (ret)
+			return ret;
+	}
+
+	/* Clear reset flags */
+	ret = regmap_write_bits(ctx->regmap, IT66121_SW_RST_REG,
+				IT66121_SW_RST_REF | IT66121_SW_RST_VID, 0);
+	if (ret)
+		return ret;
+
+	return it66121_fire_afe(ctx);
+}
+
+static inline int it66121_wait_ddc_ready(struct it66121_ctx *ctx)
+{
+	int ret, val;
+	u32 busy = IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS |
+		   IT66121_DDC_STATUS_ARBI_LOSE;
+
+	ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG, val, true,
+				       IT66121_EDID_SLEEP_US, IT66121_EDID_TIMEOUT_US);
+	if (ret)
+		return ret;
+
+	if (val & busy)
+		return -EAGAIN;
+
+	return 0;
+}
+
+static int it66121_clear_ddc_fifo(struct it66121_ctx *ctx)
+{
+	int ret;
+
+	ret = it66121_preamble_ddc(ctx);
+	if (ret)
+		return ret;
+
+	return regmap_write(ctx->regmap, IT66121_DDC_COMMAND_REG,
+			    IT66121_DDC_COMMAND_FIFO_CLR);
+}
+
+static int it66121_abort_ddc_ops(struct it66121_ctx *ctx)
+{
+	int ret;
+	unsigned int swreset, cpdesire;
+
+	ret = regmap_read(ctx->regmap, IT66121_SW_RST_REG, &swreset);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(ctx->regmap, IT66121_HDCP_REG, &cpdesire);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(ctx->regmap, IT66121_HDCP_REG,
+			   cpdesire & (~IT66121_HDCP_CPDESIRED & 0xFF));
+	if (ret)
+		return ret;
+
+	ret = regmap_write(ctx->regmap, IT66121_SW_RST_REG,
+			   (swreset | IT66121_SW_RST_HDCP));
+	if (ret)
+		return ret;
+
+	ret = it66121_preamble_ddc(ctx);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(ctx->regmap, IT66121_DDC_COMMAND_REG,
+			   IT66121_DDC_COMMAND_ABORT);
+	if (ret)
+		return ret;
+
+	return it66121_wait_ddc_ready(ctx);
+}
+
+static int it66121_get_edid_block(void *context, u8 *buf,
+				  unsigned int block, size_t len)
+{
+	struct it66121_ctx *ctx = context;
+	unsigned int val;
+	int remain = len;
+	int offset = 0;
+	int ret, cnt;
+
+	offset = (block % 2) * len;
+	block = block / 2;
+
+	ret = regmap_read(ctx->regmap, IT66121_INT_STATUS1_REG, &val);
+	if (ret)
+		return ret;
+
+	if (val & IT66121_INT_STATUS1_DDC_BUSHANG) {
+		ret = it66121_abort_ddc_ops(ctx);
+		if (ret)
+			return ret;
+	}
+
+	ret = it66121_clear_ddc_fifo(ctx);
+	if (ret)
+		return ret;
+
+	while (remain > 0) {
+		cnt = (remain > IT66121_EDID_FIFO_SIZE) ?
+				IT66121_EDID_FIFO_SIZE : remain;
+		ret = it66121_preamble_ddc(ctx);
+		if (ret)
+			return ret;
+
+		ret = regmap_write(ctx->regmap, IT66121_DDC_COMMAND_REG,
+				   IT66121_DDC_COMMAND_FIFO_CLR);
+		if (ret)
+			return ret;
+
+		ret = it66121_wait_ddc_ready(ctx);
+		if (ret)
+			return ret;
+
+		ret = regmap_read(ctx->regmap, IT66121_INT_STATUS1_REG, &val);
+		if (ret)
+			return ret;
+
+		if (val & IT66121_INT_STATUS1_DDC_BUSHANG) {
+			ret = it66121_abort_ddc_ops(ctx);
+			if (ret)
+				return ret;
+		}
+
+		ret = it66121_preamble_ddc(ctx);
+		if (ret)
+			return ret;
+
+		ret = regmap_write(ctx->regmap, IT66121_DDC_HEADER_REG,
+				   IT66121_DDC_HEADER_EDID);
+		if (ret)
+			return ret;
+
+		ret = regmap_write(ctx->regmap, IT66121_DDC_OFFSET_REG, offset);
+		if (ret)
+			return ret;
+
+		ret = regmap_write(ctx->regmap, IT66121_DDC_BYTE_REG, cnt);
+		if (ret)
+			return ret;
+
+		ret = regmap_write(ctx->regmap, IT66121_DDC_SEGMENT_REG, block);
+		if (ret)
+			return ret;
+
+		ret = regmap_write(ctx->regmap, IT66121_DDC_COMMAND_REG,
+				   IT66121_DDC_COMMAND_EDID_READ);
+		if (ret)
+			return ret;
+
+		offset += cnt;
+		remain -= cnt;
+
+		/* Per programming manual, sleep here before emptying the FIFO */
+		msleep(20);
+
+		ret = it66121_wait_ddc_ready(ctx);
+		if (ret)
+			return ret;
+
+		do {
+			ret = regmap_read(ctx->regmap, IT66121_DDC_RD_FIFO_REG, &val);
+			if (ret)
+				return ret;
+			*(buf++) = val;
+			cnt--;
+		} while (cnt > 0);
+	}
+
+	return 0;
+}
+
+static bool it66121_is_hpd_detect(struct it66121_ctx *ctx)
+{
+	int val;
+
+	if (regmap_read(ctx->regmap, IT66121_SYS_STATUS_REG, &val))
+		return false;
+
+	return val & IT66121_SYS_STATUS_HPDETECT;
+}
+
+static int it66121_bridge_attach(struct drm_bridge *bridge,
+				 enum drm_bridge_attach_flags flags)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	int ret;
+
+	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
+		return -EINVAL;
+
+	ret = drm_bridge_attach(bridge->encoder, ctx->next_bridge, bridge, flags);
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG,
+				IT66121_CLK_BANK_PWROFF_RCLK, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_INT_REG,
+				IT66121_INT_TX_CLK_OFF, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AFE_DRV_REG,
+				IT66121_AFE_DRV_PWD, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_REG,
+				IT66121_AFE_XP_PWDI | IT66121_AFE_XP_PWDPLL, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
+				IT66121_AFE_IP_PWDPLL, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AFE_DRV_REG,
+				IT66121_AFE_DRV_RST, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_REG,
+				IT66121_AFE_XP_RESETB, IT66121_AFE_XP_RESETB);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
+				IT66121_AFE_IP_RESETB, IT66121_AFE_IP_RESETB);
+	if (ret)
+		return ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_SW_RST_REG,
+				IT66121_SW_RST_REF,
+				IT66121_SW_RST_REF);
+	if (ret)
+		return ret;
+
+	/* Per programming manual, sleep here for bridge to settle */
+	msleep(50);
+
+	/* Start interrupts */
+	return regmap_write_bits(ctx->regmap, IT66121_INT_MASK1_REG,
+				 IT66121_INT_MASK1_DDC_NOACK |
+				 IT66121_INT_MASK1_DDC_FIFOERR |
+				 IT66121_INT_MASK1_DDC_BUSHANG, 0);
+}
+
+static int it66121_set_mute(struct it66121_ctx *ctx, bool mute)
+{
+	int ret;
+	unsigned int val = 0;
+
+	if (mute)
+		val = IT66121_AV_MUTE_ON;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_AV_MUTE_REG, IT66121_AV_MUTE_ON, val);
+	if (ret)
+		return ret;
+
+	return regmap_write(ctx->regmap, IT66121_PKT_GEN_CTRL_REG,
+			    IT66121_PKT_GEN_CTRL_ON | IT66121_PKT_GEN_CTRL_RPT);
+}
+
+#define MAX_OUTPUT_SEL_FORMATS	1
+
+static u32 *it66121_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)
+{
+	u32 *output_fmts;
+
+	output_fmts = kcalloc(MAX_OUTPUT_SEL_FORMATS, sizeof(*output_fmts),
+			      GFP_KERNEL);
+	if (!output_fmts)
+		return NULL;
+
+	/* TOFIX handle more than MEDIA_BUS_FMT_RGB888_1X24 as output format */
+	output_fmts[0] =  MEDIA_BUS_FMT_RGB888_1X24;
+	*num_output_fmts = 1;
+
+	return output_fmts;
+}
+
+#define MAX_INPUT_SEL_FORMATS	1
+
+static u32 *it66121_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 it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+			     GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	if (ctx->bus_width == 12)
+		/* IT66121FN Datasheet specifies Little-Endian ordering */
+		input_fmts[0] = MEDIA_BUS_FMT_RGB888_2X12_LE;
+	else
+		/* TOFIX support more input bus formats in 24bit width */
+		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+	*num_input_fmts = 1;
+
+	return input_fmts;
+}
+
+static void it66121_bridge_enable(struct drm_bridge *bridge,
+				  struct drm_bridge_state *bridge_state)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	struct drm_atomic_state *state = bridge_state->base.state;
+
+	ctx->connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
+
+	it66121_set_mute(ctx, false);
+}
+
+static void it66121_bridge_disable(struct drm_bridge *bridge,
+				   struct drm_bridge_state *bridge_state)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+
+	it66121_set_mute(ctx, true);
+
+	ctx->connector = NULL;
+}
+
+static
+void it66121_bridge_mode_set(struct drm_bridge *bridge,
+			     const struct drm_display_mode *mode,
+			     const struct drm_display_mode *adjusted_mode)
+{
+	int ret, i;
+	u8 buf[HDMI_INFOFRAME_SIZE(AVI)];
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	const u16 aviinfo_reg[HDMI_AVI_INFOFRAME_SIZE] = {
+		IT66121_AVIINFO_DB1_REG,
+		IT66121_AVIINFO_DB2_REG,
+		IT66121_AVIINFO_DB3_REG,
+		IT66121_AVIINFO_DB4_REG,
+		IT66121_AVIINFO_DB5_REG,
+		IT66121_AVIINFO_DB6_REG,
+		IT66121_AVIINFO_DB7_REG,
+		IT66121_AVIINFO_DB8_REG,
+		IT66121_AVIINFO_DB9_REG,
+		IT66121_AVIINFO_DB10_REG,
+		IT66121_AVIINFO_DB11_REG,
+		IT66121_AVIINFO_DB12_REG,
+		IT66121_AVIINFO_DB13_REG
+	};
+
+	mutex_lock(&ctx->lock);
+
+	hdmi_avi_infoframe_init(&ctx->hdmi_avi_infoframe);
+
+	ret = drm_hdmi_avi_infoframe_from_display_mode(&ctx->hdmi_avi_infoframe, ctx->connector,
+						       adjusted_mode);
+	if (ret) {
+		DRM_ERROR("Failed to setup AVI infoframe: %d\n", ret);
+		goto unlock;
+	}
+
+	ret = hdmi_avi_infoframe_pack(&ctx->hdmi_avi_infoframe, buf, sizeof(buf));
+	if (ret < 0) {
+		DRM_ERROR("Failed to pack infoframe: %d\n", ret);
+		goto unlock;
+	}
+
+	/* Write new AVI infoframe packet */
+	for (i = 0; i < HDMI_AVI_INFOFRAME_SIZE; i++) {
+		if (regmap_write(ctx->regmap, aviinfo_reg[i], buf[i + HDMI_INFOFRAME_HEADER_SIZE]))
+			goto unlock;
+	}
+	if (regmap_write(ctx->regmap, IT66121_AVIINFO_CSUM_REG, buf[3]))
+		goto unlock;
+
+	/* Enable AVI infoframe */
+	if (regmap_write(ctx->regmap, IT66121_AVI_INFO_PKT_REG,
+			 IT66121_AVI_INFO_PKT_ON | IT66121_AVI_INFO_PKT_RPT))
+		goto unlock;
+
+	/* Set TX mode to HDMI */
+	if (regmap_write(ctx->regmap, IT66121_HDMI_MODE_REG, IT66121_HDMI_MODE_HDMI))
+		goto unlock;
+
+	if (regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG,
+			      IT66121_CLK_BANK_PWROFF_TXCLK, IT66121_CLK_BANK_PWROFF_TXCLK))
+		goto unlock;
+
+	if (it66121_configure_input(ctx))
+		goto unlock;
+
+	if (it66121_configure_afe(ctx, adjusted_mode))
+		goto unlock;
+
+	regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG, IT66121_CLK_BANK_PWROFF_TXCLK, 0);
+
+unlock:
+	mutex_unlock(&ctx->lock);
+}
+
+static enum drm_mode_status it66121_bridge_mode_valid(struct drm_bridge *bridge,
+						      const struct drm_display_info *info,
+						      const struct drm_display_mode *mode)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	unsigned long max_clock;
+
+	max_clock = (ctx->bus_width == 12) ? 74250 : 148500;
+
+	if (mode->clock > max_clock)
+		return MODE_CLOCK_HIGH;
+
+	if (mode->clock < 25000)
+		return MODE_CLOCK_LOW;
+
+	return MODE_OK;
+}
+
+static enum drm_connector_status it66121_bridge_detect(struct drm_bridge *bridge)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+
+	return it66121_is_hpd_detect(ctx) ? connector_status_connected
+					  : connector_status_disconnected;
+}
+
+static void it66121_bridge_hpd_enable(struct drm_bridge *bridge)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	int ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_INT_MASK1_REG, IT66121_INT_MASK1_HPD, 0);
+	if (ret)
+		dev_err(ctx->dev, "failed to enable HPD IRQ\n");
+}
+
+static void it66121_bridge_hpd_disable(struct drm_bridge *bridge)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	int ret;
+
+	ret = regmap_write_bits(ctx->regmap, IT66121_INT_MASK1_REG,
+				IT66121_INT_MASK1_HPD, IT66121_INT_MASK1_HPD);
+	if (ret)
+		dev_err(ctx->dev, "failed to disable HPD IRQ\n");
+}
+
+static struct edid *it66121_bridge_get_edid(struct drm_bridge *bridge,
+					    struct drm_connector *connector)
+{
+	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
+	struct edid *edid;
+
+	mutex_lock(&ctx->lock);
+	edid = drm_do_get_edid(connector, it66121_get_edid_block, ctx);
+	mutex_unlock(&ctx->lock);
+
+	return edid;
+}
+
+static const struct drm_bridge_funcs it66121_bridge_funcs = {
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.attach = it66121_bridge_attach,
+	.atomic_get_output_bus_fmts = it66121_bridge_atomic_get_output_bus_fmts,
+	.atomic_get_input_bus_fmts = it66121_bridge_atomic_get_input_bus_fmts,
+	.atomic_enable = it66121_bridge_enable,
+	.atomic_disable = it66121_bridge_disable,
+	.mode_set = it66121_bridge_mode_set,
+	.mode_valid = it66121_bridge_mode_valid,
+	.detect = it66121_bridge_detect,
+	.get_edid = it66121_bridge_get_edid,
+	.hpd_enable = it66121_bridge_hpd_enable,
+	.hpd_disable = it66121_bridge_hpd_disable,
+};
+
+static irqreturn_t it66121_irq_threaded_handler(int irq, void *dev_id)
+{
+	int ret;
+	unsigned int val;
+	struct it66121_ctx *ctx = dev_id;
+	struct device *dev = ctx->dev;
+	enum drm_connector_status status;
+	bool event = false;
+
+	mutex_lock(&ctx->lock);
+
+	ret = regmap_read(ctx->regmap, IT66121_SYS_STATUS_REG, &val);
+	if (ret)
+		goto unlock;
+
+	if (!(val & IT66121_SYS_STATUS_ACTIVE_IRQ))
+		goto unlock;
+
+	ret = regmap_read(ctx->regmap, IT66121_INT_STATUS1_REG, &val);
+	if (ret) {
+		dev_err(dev, "Cannot read STATUS1_REG %d\n", ret);
+	} else {
+		if (val & IT66121_INT_STATUS1_DDC_FIFOERR)
+			it66121_clear_ddc_fifo(ctx);
+		if (val & (IT66121_INT_STATUS1_DDC_BUSHANG |
+			   IT66121_INT_STATUS1_DDC_NOACK))
+			it66121_abort_ddc_ops(ctx);
+		if (val & IT66121_INT_STATUS1_HPD_STATUS) {
+			regmap_write_bits(ctx->regmap, IT66121_INT_CLR1_REG,
+					  IT66121_INT_CLR1_HPD, IT66121_INT_CLR1_HPD);
+
+			status = it66121_is_hpd_detect(ctx) ? connector_status_connected
+							    : connector_status_disconnected;
+
+			event = true;
+		}
+	}
+
+	regmap_write_bits(ctx->regmap, IT66121_SYS_STATUS_REG,
+			  IT66121_SYS_STATUS_CLEAR_IRQ,
+			  IT66121_SYS_STATUS_CLEAR_IRQ);
+
+unlock:
+	mutex_unlock(&ctx->lock);
+
+	if (event)
+		drm_bridge_hpd_notify(&ctx->bridge, status);
+
+	return IRQ_HANDLED;
+}
+
+static int it66121_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	u32 vendor_ids[2], device_ids[2], revision_id;
+	struct device_node *ep;
+	int ret;
+	struct it66121_ctx *ctx;
+	struct device *dev = &client->dev;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(dev, "I2C check functionality failed.\n");
+		return -ENXIO;
+	}
+
+	ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+	if (!ep)
+		return -EINVAL;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->dev = dev;
+	ctx->client = client;
+
+	of_property_read_u32(ep, "bus-width", &ctx->bus_width);
+	of_node_put(ep);
+
+	if (ctx->bus_width != 12 && ctx->bus_width != 24)
+		return -EINVAL;
+
+	ep = of_graph_get_remote_node(dev->of_node, 1, -1);
+	if (!ep)
+		return -EPROBE_DEFER;
+
+	ctx->next_bridge = of_drm_find_bridge(ep);
+	of_node_put(ep);
+
+	i2c_set_clientdata(client, ctx);
+	mutex_init(&ctx->lock);
+
+	ctx->supplies[0].supply = "vcn33";
+	ctx->supplies[1].supply = "vcn18";
+	ctx->supplies[2].supply = "vrf12";
+	ret = devm_regulator_bulk_get(ctx->dev, 3, ctx->supplies);
+	if (ret) {
+		dev_err(ctx->dev, "regulator_bulk failed\n");
+		return ret;
+	}
+
+	ret = ite66121_power_on(ctx);
+	if (ret)
+		return ret;
+
+	it66121_hw_reset(ctx);
+
+	ctx->regmap = devm_regmap_init_i2c(client, &it66121_regmap_config);
+	if (IS_ERR(ctx->regmap)) {
+		ite66121_power_off(ctx);
+		return PTR_ERR(ctx);
+	}
+
+	regmap_read(ctx->regmap, IT66121_VENDOR_ID0_REG, &vendor_ids[0]);
+	regmap_read(ctx->regmap, IT66121_VENDOR_ID1_REG, &vendor_ids[1]);
+	regmap_read(ctx->regmap, IT66121_DEVICE_ID0_REG, &device_ids[0]);
+	regmap_read(ctx->regmap, IT66121_DEVICE_ID1_REG, &device_ids[1]);
+
+	/* Revision is shared with DEVICE_ID1 */
+	revision_id = FIELD_GET(IT66121_REVISION_MASK, device_ids[1]);
+	device_ids[1] &= IT66121_DEVICE_ID1_MASK;
+
+	if (vendor_ids[0] != IT66121_VENDOR_ID0 || vendor_ids[1] != IT66121_VENDOR_ID1 ||
+	    device_ids[0] != IT66121_DEVICE_ID0 || device_ids[1] != IT66121_DEVICE_ID1) {
+		ite66121_power_off(ctx);
+		return -ENODEV;
+	}
+
+	ctx->bridge.funcs = &it66121_bridge_funcs;
+	ctx->bridge.of_node = dev->of_node;
+	ctx->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
+	ctx->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_HPD;
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,	it66121_irq_threaded_handler,
+					IRQF_ONESHOT, dev_name(dev), ctx);
+	if (ret < 0) {
+		dev_err(dev, "Failed to request irq %d:%d\n", client->irq, ret);
+		ite66121_power_off(ctx);
+		return ret;
+	}
+
+	drm_bridge_add(&ctx->bridge);
+
+	dev_info(ctx->dev, "IT66121 revision %d probed\n", revision_id);
+
+	return 0;
+}
+
+static int it66121_remove(struct i2c_client *client)
+{
+	struct it66121_ctx *ctx = i2c_get_clientdata(client);
+
+	ite66121_power_off(ctx);
+	drm_bridge_remove(&ctx->bridge);
+	mutex_destroy(&ctx->lock);
+
+	return 0;
+}
+
+static const struct of_device_id it66121_dt_match[] = {
+	{ .compatible = "ite,it66121" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, it66121_dt_match);
+
+static const struct i2c_device_id it66121_id[] = {
+	{ "it66121", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, it66121_id);
+
+static struct i2c_driver it66121_driver = {
+	.driver = {
+		.name	= "it66121",
+		.of_match_table = it66121_dt_match,
+	},
+	.probe = it66121_probe,
+	.remove = it66121_remove,
+	.id_table = it66121_id,
+};
+
+module_i2c_driver(it66121_driver);
+
+MODULE_AUTHOR("Phong LE");
+MODULE_DESCRIPTION("IT66121 HDMI transmitter driver");
+MODULE_LICENSE("GPL v2");