Re: [PATCH v4 2/3] drm: bridge: add it66121 driver

From: Neil Armstrong
Date: Wed Apr 21 2021 - 07:50:57 EST


Hi,

On 21/04/2021 11:58, Paul Cercueil wrote:
> Hi Neil,
>
> Le mer. 21 avril 2021 à 11:25, Neil Armstrong <narmstrong@xxxxxxxxxxxx> a écrit :
>> Hi Paul,
>>
>> On 19/04/2021 09:12, Neil Armstrong wrote:
>>>  From: Phong LE <ple@xxxxxxxxxxxx>
>>>
>>>  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.
>>
>> Did you manage to get it working on your platform with all the needed bridge stuff ?
>>
>> Neil
>
> I think I will need a bit more time to update ingenic-drm to use the bridge stuff. That's quite a big change.
>
> So don't wait for me.

Sure, we have time for fixes until it goes into the next release anyway.

Neil

>
> Cheers,
> -Paul
>
>>>
>>>  Signed-off-by: Phong LE <ple@xxxxxxxxxxxx>
>>>  Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
>>>  ---
>>>   drivers/gpu/drm/bridge/Kconfig       |    8 +
>>>   drivers/gpu/drm/bridge/Makefile      |    1 +
>>>   drivers/gpu/drm/bridge/ite-it66121.c | 1021 ++++++++++++++++++++++++++
>>>   3 files changed, 1030 insertions(+)
>>>   create mode 100644 drivers/gpu/drm/bridge/ite-it66121.c
>>>
>>>  diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>>>  index e4110d6ca7b3..6915c38fa459 100644
>>>  --- a/drivers/gpu/drm/bridge/Kconfig
>>>  +++ b/drivers/gpu/drm/bridge/Kconfig
>>>  @@ -74,6 +74,14 @@ 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 86e7acc76f8d..4f725753117c 100644
>>>  --- a/drivers/gpu/drm/bridge/Makefile
>>>  +++ b/drivers/gpu/drm/bridge/Makefile
>>>  @@ -24,6 +24,7 @@ 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@xxxxxxxxxxxx>
>>>  + * 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");
>>>
>>
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