Re: [PATCH v2 3/4] drm: bridge: add it66121 driver

Laurent Pinchart
2020-03-13T13:56:03Z

Hi Phong,

Thank you for the patch.

On Wed, Mar 11, 2020 at 01:51:34PM +0100, Phong LE wrote:
> This commit is a simple driver for bridge HMDI it66121.
> The input format is RBG and there is no color conversion.
> Audio, HDCP and CEC are not supported yet.
>
> Signed-off-by: Phong LE <ple@baylibre.com>
> ---
> drivers/gpu/drm/bridge/Kconfig | 8 +
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/ite-it66121.c | 997 +++++++++++++++++++++++++++
> 3 files changed, 1006 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 aaed2347ace9..ae57b83f47c8 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -38,6 +38,14 @@ config DRM_DISPLAY_CONNECTOR
> on ARM-based platforms. Saying Y here when this driver is not needed
> will not cause any issue.
>
> +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 6fb062b5b0f0..9fe80e820f64 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
> +obj-$(CONFIG_DRM_ITE_IT66121) += ite-it66121.o
> obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o
> obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
> obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
> new file mode 100644
> index 000000000000..7e1a90319a6a
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ite-it66121.c
> @@ -0,0 +1,997 @@
> +// 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/device.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>

This header is not needed, you should include <gpio/consumer.h> instead.

> +#include <linux/pinctrl/consumer.h>
> +#include <linux/regmap.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_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_VENDOR_ID0 0x54
> +#define IT66121_VENDOR_ID1 0x49
> +#define IT66121_DEVICE_ID0 0x12
> +#define IT66121_DEVICE_ID1 0x06
> +#define IT66121_DEVICE_MASK 0x0F
> +#define IT66121_EDID_SLEEP 20000
> +#define IT66121_EDID_TIMEOUT 200000
> +#define IT66121_EDID_FIFO_SIZE 32
> +#define IT66121_AFE_CLK_HIGH 80000
> +
> +struct it66121_conf {
> + unsigned int input_mode_reg;
> + unsigned int input_conversion_reg;
> +};
> +
> +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;
> + struct regulator_bulk_data supplies[3];
> + bool dual_edge;
> + const struct it66121_conf *conf;
> + struct mutex lock; /* Protects fields below and device registers */
> + struct edid *edid;
> + 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 const struct it66121_conf it66121_conf_simple = {
> + .input_mode_reg = IT66121_INPUT_MODE_RGB | IT66121_INPUT_MODE_DDR,
> + .input_conversion_reg = IT66121_INPUT_CSC_NO_CONV,
> +};
> +
> +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 int ite66121_power_on(struct it66121_ctx *ctx)
> +{
> + return regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +}
> +
> +static int ite66121_power_off(struct it66121_ctx *ctx)
> +{
> + return regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +}
> +
> +static int it66121_preamble_ddc(struct it66121_ctx *ctx)
> +{
> + return regmap_write(ctx->regmap, IT66121_MASTER_SEL_REG,
> + IT66121_MASTER_SEL_HOST);
> +}
> +
> +static int it66121_fire_afe(struct it66121_ctx *ctx)
> +{
> + return regmap_write(ctx->regmap, IT66121_AFE_DRV_REG, 0);
> +}
> +
> +static int it66121_configure_input(struct it66121_ctx *ctx)
> +{
> + int ret;
> +
> + ret = regmap_write(ctx->regmap, IT66121_INPUT_MODE_REG,
> + ctx->conf->input_mode_reg);
> + if (ret)
> + return ret;
> +
> + return regmap_write(ctx->regmap, IT66121_INPUT_CSC_REG,
> + ctx->conf->input_conversion_reg);
> +}
> +
> +/**
> + * it66121_configure_afe() - Configure the analog front end
> + * @ctx: it66121_ctx object
> + *
> + * 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,
> + ~(IT66121_SW_RST_REF | IT66121_SW_RST_VID) &
> + 0xFF);
> + if (ret)
> + return ret;
> +
> + return it66121_fire_afe(ctx);
> +}
> +
> +static inline int it66121_wait_ddc_ready(struct it66121_ctx *ctx)
> +{
> + int ret, val;
> +
> + ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG,
> + val, true,
> + IT66121_EDID_SLEEP,
> + IT66121_EDID_TIMEOUT);
> + if (ret)
> + return ret;
> +
> + if (val & (IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS |
> + IT66121_DDC_STATUS_ARBI_LOSE))
> + 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;
> + 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 int it66121_connector_get_modes(struct drm_connector *connector)
> +{
> + int ret, num_modes = 0;
> + struct it66121_ctx *ctx = container_of(connector, struct it66121_ctx,
> + connector);
> +
> + if (ctx->edid)
> + return drm_add_edid_modes(connector, ctx->edid);
> +
> + mutex_lock(&ctx->lock);
> +
> + ctx->edid = drm_do_get_edid(connector, it66121_get_edid_block, ctx);
> + if (!ctx->edid) {
> + DRM_ERROR("Failed to read EDID\n");
> + goto unlock;
> + }
> +
> + ret = drm_connector_update_edid_property(connector,
> + ctx->edid);
> + if (ret) {
> + DRM_ERROR("Failed to update EDID property: %d\n", ret);
> + goto unlock;
> + }
> +
> + num_modes = drm_add_edid_modes(connector, ctx->edid);
> +
> +unlock:
> + mutex_unlock(&ctx->lock);
> +
> + return num_modes;
> +}
> +
> +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_connector_detect_ctx(struct drm_connector *connector,
> + struct drm_modeset_acquire_ctx *c,
> + bool force)
> +{
> + struct it66121_ctx *ctx = container_of(connector, struct it66121_ctx,
> + connector);
> +
> + return (it66121_is_hpd_detect(ctx)) ?
> + connector_status_connected : connector_status_disconnected;
> +}
> +
> +static enum drm_mode_status
> +it66121_connector_mode_valid(struct drm_connector *connector,
> + struct drm_display_mode *mode)
> +{
> + unsigned long max_clock;
> + struct it66121_ctx *ctx = container_of(connector, struct it66121_ctx,
> + connector);
> +
> + max_clock = ctx->dual_edge ? 74250 : 148500;
> +
> + if (mode->clock > max_clock)
> + return MODE_CLOCK_HIGH;
> +
> + if (mode->clock < 25000)
> + return MODE_CLOCK_LOW;
> +
> + return MODE_OK;
> +}
> +
> +static struct drm_connector_helper_funcs it66121_connector_helper_funcs = {
> + .get_modes = it66121_connector_get_modes,
> + .detect_ctx = it66121_connector_detect_ctx,
> + .mode_valid = it66121_connector_mode_valid,
> +};
> +
> +static const struct drm_connector_funcs it66121_connector_funcs = {
> + .reset = drm_atomic_helper_connector_reset,
> + .fill_modes = drm_helper_probe_single_connector_modes,
> + .destroy = drm_connector_cleanup,
> + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int it66121_bridge_attach(struct drm_bridge *bridge,
> + enum drm_bridge_attach_flags flags)
> +{
> + int ret;
> + struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx,
> + bridge);
> +
> + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
> + DRM_ERROR("Fix bridge driver to make connector optional!");
> + return -EINVAL;
> + }

Please make the connector optional. It's just a matter of returning
before creating the connector in this function, and exposing connector
operations in it66121_bridge_funcs. Ideally the display controller
driver should use the connector operations and create the connector
itself (there's a nice helper for that :-)), so you could drop all
connector code in this driver.

> +
> + if (!bridge->encoder) {
> + DRM_ERROR("Parent encoder object not found");
> + return -ENODEV;
> + }
> +
> + 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;
> +
> + msleep(50);
> +
> + ret = drm_connector_init(bridge->dev, &ctx->connector,
> + &it66121_connector_funcs,
> + DRM_MODE_CONNECTOR_HDMIA);
> + if (ret)
> + return ret;
> +
> + ctx->connector.polled = DRM_CONNECTOR_POLL_HPD;
> + drm_connector_helper_add(&ctx->connector,
> + &it66121_connector_helper_funcs);
> +
> + ret = drm_connector_attach_encoder(&ctx->connector, bridge->encoder);
> + if (ret)
> + return ret;
> +
> + ret = drm_connector_register(&ctx->connector);
> + if (ret)
> + return ret;
> +
> + /* Start interrupts */
> + return regmap_write_bits(ctx->regmap, IT66121_INT_MASK1_REG,
> + IT66121_INT_MASK1_DDC_NOACK |
> + IT66121_INT_MASK1_HPD |
> + IT66121_INT_MASK1_DDC_FIFOERR |
> + IT66121_INT_MASK1_DDC_BUSHANG,
> + ~(IT66121_INT_MASK1_DDC_NOACK |
> + IT66121_INT_MASK1_HPD |
> + IT66121_INT_MASK1_DDC_FIFOERR |
> + IT66121_INT_MASK1_DDC_BUSHANG) & 0xFF);

Is there a reason all those writes have to be performed here instead of
at probe time and/or enable time ?

> +}
> +
> +static int it66121_set_mute(struct it66121_ctx *ctx, bool mute)
> +{
> + int ret;
> + unsigned int val;
> +
> + val = mute ? IT66121_AV_MUTE_ON : (~IT66121_AV_MUTE_ON & 0xFF);
> + 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);
> +}
> +
> +static void it66121_bridge_enable(struct drm_bridge *bridge)
> +{
> + struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx,
> + bridge);
> +
> + it66121_set_mute(ctx, false);
> +}
> +
> +static void it66121_bridge_disable(struct drm_bridge *bridge)
> +{
> + struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx,
> + bridge);
> +
> + it66121_set_mute(ctx, true);
> +}
> +
> +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,
> + ~IT66121_CLK_BANK_PWROFF_TXCLK & 0xFF);
> +
> +unlock:
> + mutex_unlock(&ctx->lock);
> +}
> +
> +static const struct drm_bridge_funcs it66121_bridge_funcs = {
> + .attach = it66121_bridge_attach,
> + .enable = it66121_bridge_enable,
> + .disable = it66121_bridge_disable,
> + .mode_set = it66121_bridge_mode_set,
> +};
> +
> +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;
> + 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) {
> + 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);
> +
> + if (!it66121_is_hpd_detect(ctx)) {
> + kfree(ctx->edid);
> + ctx->edid = NULL;
> + }
> + 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_helper_hpd_irq_event(ctx->bridge.dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int it66121_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + u8 ids[4];
> + int i, 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;
> + }
> +
> + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> + if (!ctx)
> + return -ENOMEM;
> +
> + ctx->dev = dev;
> + ctx->client = client;
> + i2c_set_clientdata(client, ctx);
> + mutex_init(&ctx->lock);
> + ctx->conf = (struct it66121_conf *)of_device_get_match_data(dev);
> + if (!ctx->conf)
> + return -ENODEV;
> +
> + 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;
> + }
> +
> + ctx->dual_edge = of_property_read_bool(dev->of_node, "pclk-dual-edge");
> +
> + 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);

I would add an error label at the end to handle the power off, but
that's up to you.

> + }
> +
> + for (i = 0; i < 4; i++) {
> + regmap_read(ctx->regmap, i, &ret);
> + ids[i] = ret;
> + }
> +
> + if (ids[0] != IT66121_VENDOR_ID0 ||
> + ids[1] != IT66121_VENDOR_ID1 ||
> + ids[2] != IT66121_DEVICE_ID0 ||
> + ((ids[3] & IT66121_DEVICE_MASK) != IT66121_DEVICE_ID1)) {

Maybe an error message ?

> + ite66121_power_off(ctx);
> + return -ENODEV;
> + }
> +
> + ctx->bridge.funcs = &it66121_bridge_funcs;
> + ctx->bridge.of_node = dev->of_node;
> +
> + ret = devm_request_threaded_irq(dev, client->irq, NULL,
> + it66121_irq_threaded_handler,
> + IRQF_SHARED | IRQF_TRIGGER_LOW |
> + 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);
> +
> + 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);
> + kfree(ctx->edid);
> + mutex_destroy(&ctx->lock);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id it66121_dt_match[] = {
> + { .compatible = "ite,it66121",
> + .data = &it66121_conf_simple,
> + },
> + { },
> +};
> +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");

--
Regards,

Laurent Pinchart