root/drivers/gpu/drm/bridge/ite-it66121.c
// 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/media-bus-format.h>
#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_edid.h>
#include <drm/drm_modes.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include <sound/hdmi-codec.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_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 IT6610_AFE_XP_BYPASS                    BIT(0)

#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_CTS_CTRL_REG                0xC5
#define IT66121_PKT_CTS_CTRL_SEL                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_CLK_CTRL0_REG                   0x58
#define IT66121_CLK_CTRL0_AUTO_OVER_SAMPLING    BIT(4)
#define IT66121_CLK_CTRL0_EXT_MCLK_MASK         GENMASK(3, 2)
#define IT66121_CLK_CTRL0_EXT_MCLK_128FS        (0 << 2)
#define IT66121_CLK_CTRL0_EXT_MCLK_256FS        BIT(2)
#define IT66121_CLK_CTRL0_EXT_MCLK_512FS        (2 << 2)
#define IT66121_CLK_CTRL0_EXT_MCLK_1024FS       (3 << 2)
#define IT66121_CLK_CTRL0_AUTO_IPCLK            BIT(0)
#define IT66121_CLK_STATUS1_REG                 0x5E
#define IT66121_CLK_STATUS2_REG                 0x5F

#define IT66121_AUD_CTRL0_REG                   0xE0
#define IT66121_AUD_SWL                         (3 << 6)
#define IT66121_AUD_16BIT                       (0 << 6)
#define IT66121_AUD_18BIT                       BIT(6)
#define IT66121_AUD_20BIT                       (2 << 6)
#define IT66121_AUD_24BIT                       (3 << 6)
#define IT66121_AUD_SPDIFTC                     BIT(5)
#define IT66121_AUD_SPDIF                       BIT(4)
#define IT66121_AUD_I2S                         (0 << 4)
#define IT66121_AUD_EN_I2S3                     BIT(3)
#define IT66121_AUD_EN_I2S2                     BIT(2)
#define IT66121_AUD_EN_I2S1                     BIT(1)
#define IT66121_AUD_EN_I2S0                     BIT(0)
#define IT66121_AUD_CTRL0_AUD_SEL               BIT(4)

#define IT66121_AUD_CTRL1_REG                   0xE1
#define IT66121_AUD_FIFOMAP_REG                 0xE2
#define IT66121_AUD_CTRL3_REG                   0xE3
#define IT66121_AUD_SRCVALID_FLAT_REG           0xE4
#define IT66121_AUD_FLAT_SRC0                   BIT(4)
#define IT66121_AUD_FLAT_SRC1                   BIT(5)
#define IT66121_AUD_FLAT_SRC2                   BIT(6)
#define IT66121_AUD_FLAT_SRC3                   BIT(7)
#define IT66121_AUD_HDAUDIO_REG                 0xE5

#define IT66121_AUD_PKT_CTS0_REG                0x130
#define IT66121_AUD_PKT_CTS1_REG                0x131
#define IT66121_AUD_PKT_CTS2_REG                0x132
#define IT66121_AUD_PKT_N0_REG                  0x133
#define IT66121_AUD_PKT_N1_REG                  0x134
#define IT66121_AUD_PKT_N2_REG                  0x135

#define IT66121_AUD_CHST_MODE_REG               0x191
#define IT66121_AUD_CHST_CAT_REG                0x192
#define IT66121_AUD_CHST_SRCNUM_REG             0x193
#define IT66121_AUD_CHST_CHTNUM_REG             0x194
#define IT66121_AUD_CHST_CA_FS_REG              0x198
#define IT66121_AUD_CHST_OFS_WL_REG             0x199

#define IT66121_AUD_PKT_CTS_CNT0_REG            0x1A0
#define IT66121_AUD_PKT_CTS_CNT1_REG            0x1A1
#define IT66121_AUD_PKT_CTS_CNT2_REG            0x1A2

#define IT66121_AUD_FS_22P05K                   0x4
#define IT66121_AUD_FS_44P1K                    0x0
#define IT66121_AUD_FS_88P2K                    0x8
#define IT66121_AUD_FS_176P4K                   0xC
#define IT66121_AUD_FS_24K                      0x6
#define IT66121_AUD_FS_48K                      0x2
#define IT66121_AUD_FS_96K                      0xA
#define IT66121_AUD_FS_192K                     0xE
#define IT66121_AUD_FS_768K                     0x9
#define IT66121_AUD_FS_32K                      0x3
#define IT66121_AUD_FS_OTHER                    0x1

#define IT66121_AUD_SWL_21BIT                   0xD
#define IT66121_AUD_SWL_24BIT                   0xB
#define IT66121_AUD_SWL_23BIT                   0x9
#define IT66121_AUD_SWL_22BIT                   0x5
#define IT66121_AUD_SWL_20BIT                   0x3
#define IT66121_AUD_SWL_17BIT                   0xC
#define IT66121_AUD_SWL_19BIT                   0x8
#define IT66121_AUD_SWL_18BIT                   0x4
#define IT66121_AUD_SWL_16BIT                   0x2
#define IT66121_AUD_SWL_NOT_INDICATED           0x0

#define IT66121_AFE_CLK_HIGH                    80000 /* Khz */

enum chip_id {
        ID_IT6610,
        ID_IT66121,
        ID_IT66122,
};

struct it66121_chip_info {
        enum chip_id id;
        u16 vid, pid;
};

struct it66121_ctx {
        struct regmap *regmap;
        struct drm_bridge bridge;
        struct drm_connector *connector;
        struct device *dev;
        struct gpio_desc *gpio_reset;
        struct i2c_client *client;
        u32 bus_width;
        struct mutex lock; /* Protects fields below and device registers */
        struct hdmi_avi_infoframe hdmi_avi_infoframe;
        struct {
                struct platform_device *pdev;
                u8 ch_enable;
                u8 fs;
                u8 swl;
                bool auto_cts;
        } audio;
        enum chip_id id;
};

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 = 0x100,
        },
};

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 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_GAINBIT);
                if (ret)
                        return ret;

                if (ctx->id == ID_IT66121 || ctx->id == ID_IT66122) {
                        ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
                                                IT66121_AFE_IP_EC1, 0);
                        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_ER0);
                if (ret)
                        return ret;

                if (ctx->id == ID_IT66121 || ctx->id == ID_IT66122) {
                        ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
                                                IT66121_AFE_IP_EC1,
                                                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;

        if (ctx->id == ID_IT6610) {
                ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_REG,
                                        IT6610_AFE_XP_BYPASS,
                                        IT6610_AFE_XP_BYPASS);
                if (ret)
                        return ret;
        }

        return it66121_fire_afe(ctx);
}

static inline int it66121_wait_ddc_ready(struct it66121_ctx *ctx)
{
        int ret, val;
        u32 error = IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS |
                    IT66121_DDC_STATUS_ARBI_LOSE;
        u32 done = IT66121_DDC_STATUS_TX_DONE;

        ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG, val,
                                       val & (error | done), IT66121_EDID_SLEEP_US,
                                       IT66121_EDID_TIMEOUT_US);
        if (ret)
                return ret;

        if (val & error)
                return -EAGAIN;

        return 0;
}

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;
        int remain = len;
        int offset = 0;
        int ret, cnt;

        offset = (block % 2) * len;
        block = block / 2;

        while (remain > 0) {
                cnt = (remain > IT66121_EDID_FIFO_SIZE) ?
                                IT66121_EDID_FIFO_SIZE : remain;

                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_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;

                ret = it66121_wait_ddc_ready(ctx);
                if (ret) {
                        it66121_abort_ddc_ops(ctx);
                        return ret;
                }

                ret = regmap_noinc_read(ctx->regmap, IT66121_DDC_RD_FIFO_REG,
                                        buf, cnt);
                if (ret)
                        return ret;

                buf += cnt;
        }

        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,
                                 struct drm_encoder *encoder,
                                 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(encoder, ctx->bridge.next_bridge, bridge, flags);
        if (ret)
                return ret;

        if (ctx->id == ID_IT66121 || ctx->id == ID_IT66122) {
                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);

        return 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_atomic_state *state)
{
        struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);

        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_atomic_state *state)
{
        struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);

        it66121_set_mute(ctx, true);

        ctx->connector = NULL;
}

static int it66121_bridge_check(struct drm_bridge *bridge,
                                struct drm_bridge_state *bridge_state,
                                struct drm_crtc_state *crtc_state,
                                struct drm_connector_state *conn_state)
{
        struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);

        if (ctx->id == ID_IT6610) {
                /* The IT6610 only supports these settings */
                bridge_state->input_bus_cfg.flags |= DRM_BUS_FLAG_DE_HIGH |
                        DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
                bridge_state->input_bus_cfg.flags &=
                        ~DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE;
        }

        return 0;
}

static
void it66121_bridge_mode_set(struct drm_bridge *bridge,
                             const struct drm_display_mode *mode,
                             const struct drm_display_mode *adjusted_mode)
{
        u8 buf[HDMI_INFOFRAME_SIZE(AVI)];
        struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
        int ret;

        mutex_lock(&ctx->lock);

        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 */
        ret = regmap_bulk_write(ctx->regmap, IT66121_AVIINFO_DB1_REG,
                                &buf[HDMI_INFOFRAME_HEADER_SIZE],
                                HDMI_AVI_INFOFRAME_SIZE);
        if (ret)
                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 ((ctx->id == ID_IT66121 || ctx->id == ID_IT66122) &&
            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;

        if ((ctx->id == ID_IT66121 || ctx->id == ID_IT66122) &&
            regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG,
                              IT66121_CLK_BANK_PWROFF_TXCLK, 0)) {
                goto unlock;
        }

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 drm_connector *connector)
{
        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 const struct drm_edid *it66121_bridge_edid_read(struct drm_bridge *bridge,
                                                       struct drm_connector *connector)
{
        struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
        const struct drm_edid *drm_edid;
        int ret;

        mutex_lock(&ctx->lock);
        ret = it66121_preamble_ddc(ctx);
        if (ret) {
                drm_edid = NULL;
                goto out_unlock;
        }

        ret = regmap_write(ctx->regmap, IT66121_DDC_HEADER_REG,
                           IT66121_DDC_HEADER_EDID);
        if (ret) {
                drm_edid = NULL;
                goto out_unlock;
        }

        drm_edid = drm_edid_read_custom(connector, it66121_get_edid_block, ctx);

out_unlock:
        mutex_unlock(&ctx->lock);

        return drm_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,
        .atomic_check = it66121_bridge_check,
        .mode_set = it66121_bridge_mode_set,
        .mode_valid = it66121_bridge_mode_valid,
        .detect = it66121_bridge_detect,
        .edid_read = it66121_bridge_edid_read,
        .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_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 it661221_set_chstat(struct it66121_ctx *ctx, u8 iec60958_chstat[])
{
        int ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CHST_MODE_REG, iec60958_chstat[0] & 0x7C);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CHST_CAT_REG, iec60958_chstat[1]);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CHST_SRCNUM_REG, iec60958_chstat[2] & 0x0F);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CHST_CHTNUM_REG,
                           (iec60958_chstat[2] >> 4) & 0x0F);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CHST_CA_FS_REG, iec60958_chstat[3]);
        if (ret)
                return ret;

        return regmap_write(ctx->regmap, IT66121_AUD_CHST_OFS_WL_REG, iec60958_chstat[4]);
}

static int it661221_set_lpcm_audio(struct it66121_ctx *ctx, u8 audio_src_num, u8 audio_swl)
{
        int ret;
        unsigned int audio_enable = 0;
        unsigned int audio_format = 0;

        switch (audio_swl) {
        case 16:
                audio_enable |= IT66121_AUD_16BIT;
                break;
        case 18:
                audio_enable |= IT66121_AUD_18BIT;
                break;
        case 20:
                audio_enable |= IT66121_AUD_20BIT;
                break;
        case 24:
        default:
                audio_enable |= IT66121_AUD_24BIT;
                break;
        }

        audio_format |= 0x40;
        switch (audio_src_num) {
        case 4:
                audio_enable |= IT66121_AUD_EN_I2S3 | IT66121_AUD_EN_I2S2 |
                                IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0;
                break;
        case 3:
                audio_enable |= IT66121_AUD_EN_I2S2 | IT66121_AUD_EN_I2S1 |
                                IT66121_AUD_EN_I2S0;
                break;
        case 2:
                audio_enable |= IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0;
                break;
        case 1:
        default:
                audio_format &= ~0x40;
                audio_enable |= IT66121_AUD_EN_I2S0;
                break;
        }

        audio_format |= 0x01;
        ctx->audio.ch_enable = audio_enable;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL0_REG, audio_enable & 0xF0);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL1_REG, audio_format);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_FIFOMAP_REG, 0xE4);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL3_REG, 0x00);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG, 0x00);
        if (ret)
                return ret;

        return regmap_write(ctx->regmap, IT66121_AUD_HDAUDIO_REG, 0x00);
}

static int it661221_set_ncts(struct it66121_ctx *ctx, u8 fs)
{
        int ret;
        unsigned int n;

        switch (fs) {
        case IT66121_AUD_FS_32K:
                n = 4096;
                break;
        case IT66121_AUD_FS_44P1K:
                n = 6272;
                break;
        case IT66121_AUD_FS_48K:
                n = 6144;
                break;
        case IT66121_AUD_FS_88P2K:
                n = 12544;
                break;
        case IT66121_AUD_FS_96K:
                n = 12288;
                break;
        case IT66121_AUD_FS_176P4K:
                n = 25088;
                break;
        case IT66121_AUD_FS_192K:
                n = 24576;
                break;
        case IT66121_AUD_FS_768K:
                n = 24576;
                break;
        default:
                n = 6144;
                break;
        }

        ret = regmap_write(ctx->regmap, IT66121_AUD_PKT_N0_REG, (u8)((n) & 0xFF));
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_PKT_N1_REG, (u8)((n >> 8) & 0xFF));
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, IT66121_AUD_PKT_N2_REG, (u8)((n >> 16) & 0xF));
        if (ret)
                return ret;

        if (ctx->audio.auto_cts) {
                u8 loop_cnt = 255;
                u8 cts_stable_cnt = 0;
                unsigned int sum_cts = 0;
                unsigned int cts = 0;
                unsigned int last_cts = 0;
                unsigned int diff;
                unsigned int val;

                while (loop_cnt--) {
                        msleep(30);
                        regmap_read(ctx->regmap, IT66121_AUD_PKT_CTS_CNT2_REG, &val);
                        cts = val << 12;
                        regmap_read(ctx->regmap, IT66121_AUD_PKT_CTS_CNT1_REG, &val);
                        cts |= val << 4;
                        regmap_read(ctx->regmap, IT66121_AUD_PKT_CTS_CNT0_REG, &val);
                        cts |= val >> 4;
                        if (cts == 0) {
                                continue;
                        } else {
                                if (last_cts > cts)
                                        diff = last_cts - cts;
                                else
                                        diff = cts - last_cts;
                                last_cts = cts;
                                if (diff < 5) {
                                        cts_stable_cnt++;
                                        sum_cts += cts;
                                } else {
                                        cts_stable_cnt = 0;
                                        sum_cts = 0;
                                        continue;
                                }

                                if (cts_stable_cnt >= 32) {
                                        last_cts = (sum_cts >> 5);
                                        break;
                                }
                        }
                }

                regmap_write(ctx->regmap, IT66121_AUD_PKT_CTS0_REG, (u8)((last_cts) & 0xFF));
                regmap_write(ctx->regmap, IT66121_AUD_PKT_CTS1_REG, (u8)((last_cts >> 8) & 0xFF));
                regmap_write(ctx->regmap, IT66121_AUD_PKT_CTS2_REG, (u8)((last_cts >> 16) & 0x0F));
        }

        ret = regmap_write(ctx->regmap, 0xF8, 0xC3);
        if (ret)
                return ret;

        ret = regmap_write(ctx->regmap, 0xF8, 0xA5);
        if (ret)
                return ret;

        if (ctx->audio.auto_cts) {
                ret = regmap_write_bits(ctx->regmap, IT66121_PKT_CTS_CTRL_REG,
                                        IT66121_PKT_CTS_CTRL_SEL,
                                        1);
        } else {
                ret = regmap_write_bits(ctx->regmap, IT66121_PKT_CTS_CTRL_REG,
                                        IT66121_PKT_CTS_CTRL_SEL,
                                        0);
        }

        if (ret)
                return ret;

        return regmap_write(ctx->regmap, 0xF8, 0xFF);
}

static int it661221_audio_output_enable(struct it66121_ctx *ctx, bool enable)
{
        int ret;

        if (enable) {
                ret = regmap_write_bits(ctx->regmap, IT66121_SW_RST_REG,
                                        IT66121_SW_RST_AUD | IT66121_SW_RST_AREF,
                                        0);
                if (ret)
                        return ret;

                ret = regmap_write_bits(ctx->regmap, IT66121_AUD_CTRL0_REG,
                                        IT66121_AUD_EN_I2S3 | IT66121_AUD_EN_I2S2 |
                                        IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0,
                                        ctx->audio.ch_enable);
        } else {
                ret = regmap_write_bits(ctx->regmap, IT66121_AUD_CTRL0_REG,
                                        IT66121_AUD_EN_I2S3 | IT66121_AUD_EN_I2S2 |
                                        IT66121_AUD_EN_I2S1 | IT66121_AUD_EN_I2S0,
                                        ctx->audio.ch_enable & 0xF0);
                if (ret)
                        return ret;

                ret = regmap_write_bits(ctx->regmap, IT66121_SW_RST_REG,
                                        IT66121_SW_RST_AUD | IT66121_SW_RST_AREF,
                                        IT66121_SW_RST_AUD | IT66121_SW_RST_AREF);
        }

        return ret;
}

static int it661221_audio_ch_enable(struct it66121_ctx *ctx, bool enable)
{
        int ret;

        if (enable) {
                ret = regmap_write(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG, 0);
                if (ret)
                        return ret;

                ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL0_REG, ctx->audio.ch_enable);
        } else {
                ret = regmap_write(ctx->regmap, IT66121_AUD_CTRL0_REG, ctx->audio.ch_enable & 0xF0);
        }

        return ret;
}

static int it66121_audio_hw_params(struct device *dev, void *data,
                                   struct hdmi_codec_daifmt *daifmt,
                                   struct hdmi_codec_params *params)
{
        u8 fs;
        u8 swl;
        int ret;
        struct it66121_ctx *ctx = dev_get_drvdata(dev);
        static u8 iec60958_chstat[5];
        unsigned int channels = params->channels;
        unsigned int sample_rate = params->sample_rate;
        unsigned int sample_width = params->sample_width;

        mutex_lock(&ctx->lock);
        dev_dbg(dev, "%s: %u, %u, %u, %u\n", __func__,
                daifmt->fmt, sample_rate, sample_width, channels);

        switch (daifmt->fmt) {
        case HDMI_I2S:
                dev_dbg(dev, "Using HDMI I2S\n");
                break;
        default:
                dev_err(dev, "Invalid or unsupported DAI format %d\n", daifmt->fmt);
                ret = -EINVAL;
                goto out;
        }

        // Set audio clock recovery (N/CTS)
        ret = regmap_write(ctx->regmap, IT66121_CLK_CTRL0_REG,
                           IT66121_CLK_CTRL0_AUTO_OVER_SAMPLING |
                           IT66121_CLK_CTRL0_EXT_MCLK_256FS |
                           IT66121_CLK_CTRL0_AUTO_IPCLK);
        if (ret)
                goto out;

        ret = regmap_write_bits(ctx->regmap, IT66121_AUD_CTRL0_REG,
                                IT66121_AUD_CTRL0_AUD_SEL, 0); // remove spdif selection
        if (ret)
                goto out;

        switch (sample_rate) {
        case 44100L:
                fs = IT66121_AUD_FS_44P1K;
                break;
        case 88200L:
                fs = IT66121_AUD_FS_88P2K;
                break;
        case 176400L:
                fs = IT66121_AUD_FS_176P4K;
                break;
        case 32000L:
                fs = IT66121_AUD_FS_32K;
                break;
        case 48000L:
                fs = IT66121_AUD_FS_48K;
                break;
        case 96000L:
                fs = IT66121_AUD_FS_96K;
                break;
        case 192000L:
                fs = IT66121_AUD_FS_192K;
                break;
        case 768000L:
                fs = IT66121_AUD_FS_768K;
                break;
        default:
                fs = IT66121_AUD_FS_48K;
                break;
        }

        ctx->audio.fs = fs;
        ret = it661221_set_ncts(ctx, fs);
        if (ret) {
                dev_err(dev, "Failed to set N/CTS: %d\n", ret);
                goto out;
        }

        // Set audio format register (except audio channel enable)
        ret = it661221_set_lpcm_audio(ctx, (channels + 1) / 2, sample_width);
        if (ret) {
                dev_err(dev, "Failed to set LPCM audio: %d\n", ret);
                goto out;
        }

        // Set audio channel status
        iec60958_chstat[0] = 0;
        if ((channels + 1) / 2 == 1)
                iec60958_chstat[0] |= 0x1;
        iec60958_chstat[0] &= ~(1 << 1);
        iec60958_chstat[1] = 0;
        iec60958_chstat[2] = (channels + 1) / 2;
        iec60958_chstat[2] |= (channels << 4) & 0xF0;
        iec60958_chstat[3] = fs;

        switch (sample_width) {
        case 21L:
                swl = IT66121_AUD_SWL_21BIT;
                break;
        case 24L:
                swl = IT66121_AUD_SWL_24BIT;
                break;
        case 23L:
                swl = IT66121_AUD_SWL_23BIT;
                break;
        case 22L:
                swl = IT66121_AUD_SWL_22BIT;
                break;
        case 20L:
                swl = IT66121_AUD_SWL_20BIT;
                break;
        case 17L:
                swl = IT66121_AUD_SWL_17BIT;
                break;
        case 19L:
                swl = IT66121_AUD_SWL_19BIT;
                break;
        case 18L:
                swl = IT66121_AUD_SWL_18BIT;
                break;
        case 16L:
                swl = IT66121_AUD_SWL_16BIT;
                break;
        default:
                swl = IT66121_AUD_SWL_NOT_INDICATED;
                break;
        }

        iec60958_chstat[4] = (((~fs) << 4) & 0xF0) | swl;
        ret = it661221_set_chstat(ctx, iec60958_chstat);
        if (ret) {
                dev_err(dev, "Failed to set channel status: %d\n", ret);
                goto out;
        }

        // Enable audio channel enable while input clock stable (if SPDIF).
        ret = it661221_audio_ch_enable(ctx, true);
        if (ret) {
                dev_err(dev, "Failed to enable audio channel: %d\n", ret);
                goto out;
        }

        ret = regmap_write_bits(ctx->regmap, IT66121_INT_MASK1_REG,
                                IT66121_INT_MASK1_AUD_OVF,
                                0);
        if (ret)
                goto out;

        dev_dbg(dev, "HDMI audio enabled.\n");
out:
        mutex_unlock(&ctx->lock);

        return ret;
}

static int it66121_audio_startup(struct device *dev, void *data)
{
        int ret;
        struct it66121_ctx *ctx = dev_get_drvdata(dev);

        mutex_lock(&ctx->lock);
        ret = it661221_audio_output_enable(ctx, true);
        if (ret)
                dev_err(dev, "Failed to enable audio output: %d\n", ret);

        mutex_unlock(&ctx->lock);

        return ret;
}

static void it66121_audio_shutdown(struct device *dev, void *data)
{
        int ret;
        struct it66121_ctx *ctx = dev_get_drvdata(dev);

        mutex_lock(&ctx->lock);
        ret = it661221_audio_output_enable(ctx, false);
        if (ret)
                dev_err(dev, "Failed to disable audio output: %d\n", ret);

        mutex_unlock(&ctx->lock);
}

static int it66121_audio_mute(struct device *dev, void *data,
                              bool enable, int direction)
{
        int ret;
        struct it66121_ctx *ctx = dev_get_drvdata(dev);

        dev_dbg(dev, "%s: enable=%s, direction=%d\n",
                __func__, enable ? "true" : "false", direction);

        mutex_lock(&ctx->lock);

        if (enable) {
                ret = regmap_write_bits(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG,
                                        IT66121_AUD_FLAT_SRC0 | IT66121_AUD_FLAT_SRC1 |
                                        IT66121_AUD_FLAT_SRC2 | IT66121_AUD_FLAT_SRC3,
                                        IT66121_AUD_FLAT_SRC0 | IT66121_AUD_FLAT_SRC1 |
                                        IT66121_AUD_FLAT_SRC2 | IT66121_AUD_FLAT_SRC3);
        } else {
                ret = regmap_write_bits(ctx->regmap, IT66121_AUD_SRCVALID_FLAT_REG,
                                        IT66121_AUD_FLAT_SRC0 | IT66121_AUD_FLAT_SRC1 |
                                        IT66121_AUD_FLAT_SRC2 | IT66121_AUD_FLAT_SRC3,
                                        0);
        }

        mutex_unlock(&ctx->lock);

        return ret;
}

static int it66121_audio_get_eld(struct device *dev, void *data,
                                 u8 *buf, size_t len)
{
        struct it66121_ctx *ctx = dev_get_drvdata(dev);

        mutex_lock(&ctx->lock);
        if (!ctx->connector) {
                /* Pass en empty ELD if connector not available */
                dev_dbg(dev, "No connector present, passing empty EDID data");
                memset(buf, 0, len);
        } else {
                mutex_lock(&ctx->connector->eld_mutex);
                memcpy(buf, ctx->connector->eld,
                       min(sizeof(ctx->connector->eld), len));
                mutex_unlock(&ctx->connector->eld_mutex);
        }
        mutex_unlock(&ctx->lock);

        return 0;
}

static const struct hdmi_codec_ops it66121_audio_codec_ops = {
        .hw_params = it66121_audio_hw_params,
        .audio_startup = it66121_audio_startup,
        .audio_shutdown = it66121_audio_shutdown,
        .mute_stream = it66121_audio_mute,
        .get_eld = it66121_audio_get_eld,
};

static int it66121_audio_codec_init(struct it66121_ctx *ctx, struct device *dev)
{
        struct hdmi_codec_pdata codec_data = {
                .ops = &it66121_audio_codec_ops,
                .i2s = 1, /* Only i2s support for now */
                .spdif = 0,
                .max_i2s_channels = 8,
                .no_capture_mute = 1,
        };

        if (!of_property_present(dev->of_node, "#sound-dai-cells")) {
                dev_info(dev, "No \"#sound-dai-cells\", no audio\n");
                return 0;
        }

        ctx->audio.pdev = platform_device_register_data(dev,
                                                        HDMI_CODEC_DRV_NAME,
                                                        PLATFORM_DEVID_AUTO,
                                                        &codec_data,
                                                        sizeof(codec_data));

        if (IS_ERR(ctx->audio.pdev)) {
                dev_err(dev, "Failed to initialize HDMI audio codec: %d\n",
                        PTR_ERR_OR_ZERO(ctx->audio.pdev));
        }

        return PTR_ERR_OR_ZERO(ctx->audio.pdev);
}

static const char * const it66121_supplies[] = {
        "vcn33", "vcn18", "vrf12"
};

static const struct it66121_chip_info it66xx_chip_info[] = {
        {.id = ID_IT6610, .vid = 0xca00, .pid = 0x0611 },
        {.id = ID_IT66121, .vid = 0x4954, .pid = 0x0612 },
        {.id = ID_IT66122, .vid = 0x4954, .pid = 0x0622 },
};

static int it66121_probe(struct i2c_client *client)
{
        u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
        struct device_node *ep;
        int ret, i;
        struct it66121_ctx *ctx;
        struct device *dev = &client->dev;
        const struct it66121_chip_info *chip_info;

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                dev_err(dev, "I2C check functionality failed.\n");
                return -ENXIO;
        }

        ctx = devm_drm_bridge_alloc(dev, struct it66121_ctx, bridge,
                                    &it66121_bridge_funcs);
        if (IS_ERR(ctx))
                return PTR_ERR(ctx);

        ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
        if (!ep)
                return -EINVAL;

        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) {
                dev_err(ctx->dev, "The endpoint is unconnected\n");
                return -EINVAL;
        }

        ctx->bridge.next_bridge = of_drm_find_and_get_bridge(ep);
        of_node_put(ep);
        if (!ctx->bridge.next_bridge) {
                dev_dbg(ctx->dev, "Next bridge not found, deferring probe\n");
                return -EPROBE_DEFER;
        }

        i2c_set_clientdata(client, ctx);
        mutex_init(&ctx->lock);

        ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(it66121_supplies),
                                             it66121_supplies);
        if (ret) {
                dev_err(dev, "Failed to enable power supplies\n");
                return ret;
        }

        it66121_hw_reset(ctx);

        ctx->regmap = devm_regmap_init_i2c(client, &it66121_regmap_config);
        if (IS_ERR(ctx->regmap))
                return PTR_ERR(ctx->regmap);

        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;

        for (i = 0; i < ARRAY_SIZE(it66xx_chip_info); i++) {
                chip_info = &it66xx_chip_info[i];
                if ((vendor_ids[1] << 8 | vendor_ids[0]) == chip_info->vid &&
                    (device_ids[1] << 8 | device_ids[0]) == chip_info->pid) {
                        ctx->id = chip_info->id;
                        break;
                }
        }

        if (i == ARRAY_SIZE(it66xx_chip_info))
                return -ENODEV;

        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;
        if (client->irq > 0) {
                ctx->bridge.ops |= 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);
                        return ret;
                }
        }

        it66121_audio_codec_init(ctx, dev);

        drm_bridge_add(&ctx->bridge);

        dev_info(ctx->dev, "IT66121 revision %d probed\n", revision_id);

        return 0;
}

static void it66121_remove(struct i2c_client *client)
{
        struct it66121_ctx *ctx = i2c_get_clientdata(client);

        drm_bridge_remove(&ctx->bridge);
        mutex_destroy(&ctx->lock);
}

static const struct of_device_id it66121_dt_match[] = {
        { .compatible = "ite,it6610" },
        { .compatible = "ite,it66121" },
        { .compatible = "ite,it66122" },
        { }
};
MODULE_DEVICE_TABLE(of, it66121_dt_match);

static const struct i2c_device_id it66121_id[] = {
        { .name = "it6610" },
        { .name = "it66121" },
        { .name = "it66122" },
        { }
};
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");