[PATCH 2/8] drm/loongson: Introduce a drm bridge driver for it66121 HDMI transmitter

From: Sui Jingfeng
Date: Sun Oct 29 2023 - 15:46:40 EST


The IT66121 is a DVO to HDMI converter, LS3A5000+LS7A1000 ML5A_MB use this
chip to support HDMI output. Thus add a drm bridge based driver for it.
This patch is developed with drivers/gpu/drm/bridge/ite-it66121.c as base.

Signed-off-by: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
---
drivers/gpu/drm/loongson/Kconfig | 1 +
drivers/gpu/drm/loongson/Makefile | 2 +
drivers/gpu/drm/loongson/ite_it66121.c | 749 ++++++++++++++++++++
drivers/gpu/drm/loongson/ite_it66121.h | 19 +
drivers/gpu/drm/loongson/ite_it66121_regs.h | 268 +++++++
5 files changed, 1039 insertions(+)
create mode 100644 drivers/gpu/drm/loongson/ite_it66121.c
create mode 100644 drivers/gpu/drm/loongson/ite_it66121.h
create mode 100644 drivers/gpu/drm/loongson/ite_it66121_regs.h

diff --git a/drivers/gpu/drm/loongson/Kconfig b/drivers/gpu/drm/loongson/Kconfig
index df6946d505fa..a96f5699099e 100644
--- a/drivers/gpu/drm/loongson/Kconfig
+++ b/drivers/gpu/drm/loongson/Kconfig
@@ -7,6 +7,7 @@ config DRM_LOONGSON
select DRM_TTM
select I2C
select I2C_ALGOBIT
+ select REGMAP_I2C
help
This is a DRM driver for Loongson Graphics, it may including
LS7A2000, LS7A1000, LS2K2000 and LS2K1000 etc. Loongson LS7A
diff --git a/drivers/gpu/drm/loongson/Makefile b/drivers/gpu/drm/loongson/Makefile
index bef00b2c5569..1459d19b2c90 100644
--- a/drivers/gpu/drm/loongson/Makefile
+++ b/drivers/gpu/drm/loongson/Makefile
@@ -20,4 +20,6 @@ loongson-y += loongson_device.o \
loongson_module.o \
loongson_vbios.o

+loongson-y += ite_it66121.o
+
obj-$(CONFIG_DRM_LOONGSON) += loongson.o
diff --git a/drivers/gpu/drm/loongson/ite_it66121.c b/drivers/gpu/drm/loongson/ite_it66121.c
new file mode 100644
index 000000000000..7b085575f864
--- /dev/null
+++ b/drivers/gpu/drm/loongson/ite_it66121.c
@@ -0,0 +1,749 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 BayLibre, SAS
+ * Author: Phong LE <ple@xxxxxxxxxxxx>
+ * Copyright (C) 2018-2019, Artem Mygaiev
+ * Copyright (C) 2017, Fresco Logic, Incorporated.
+ *
+ * IT66121 HDMI transmitter driver
+ */
+
+#include <linux/media-bus-format.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/bitfield.h>
+#include <linux/property.h>
+#include <linux/regmap.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 "ite_it66121.h"
+#include "ite_it66121_regs.h"
+
+#define IT66121_CHIP_NAME "IT66121"
+
+struct it66121_bridge {
+ struct drm_bridge bridge;
+ struct drm_connector connector;
+ struct regmap *regmap;
+ struct i2c_client *client;
+ /* Protects fields below and device registers */
+ struct mutex lock;
+ u16 vendor_id;
+ u16 device_id;
+ u32 revision;
+};
+
+static inline struct it66121_bridge *
+bridge_to_it66121(struct drm_bridge *bridge)
+{
+ return container_of(bridge, struct it66121_bridge, bridge);
+}
+
+static inline struct it66121_bridge *
+connector_to_it66121(struct drm_connector *connector)
+{
+ return container_of(connector, struct it66121_bridge, connector);
+}
+
+static const struct regmap_range_cfg it66121_regmap_banks[] = {
+ {
+ .name = IT66121_CHIP_NAME,
+ .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 inline int it66121_preamble_ddc(struct it66121_bridge *itb)
+{
+ return regmap_write(itb->regmap, IT66121_MASTER_SEL_REG,
+ IT66121_MASTER_SEL_HOST);
+}
+
+static inline int it66121_fire_afe(struct it66121_bridge *itb)
+{
+ return regmap_write(itb->regmap, IT66121_AFE_DRV_REG, 0);
+}
+
+static int it66121_configure_input(struct it66121_bridge *itb)
+{
+ int ret;
+
+ ret = regmap_write(itb->regmap, IT66121_INPUT_MODE_REG,
+ IT66121_INPUT_MODE_RGB888);
+ if (ret)
+ return ret;
+
+ return regmap_write(itb->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_bridge *itb,
+ const struct drm_display_mode *mode)
+{
+ int ret;
+
+ ret = regmap_write(itb->regmap, IT66121_AFE_DRV_REG,
+ IT66121_AFE_DRV_RST);
+ if (ret)
+ return ret;
+
+ if (mode->clock > IT66121_AFE_CLK_HIGH) {
+ ret = regmap_write_bits(itb->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(itb->regmap, IT66121_AFE_IP_REG,
+ IT66121_AFE_IP_GAINBIT |
+ IT66121_AFE_IP_ER0,
+ IT66121_AFE_IP_GAINBIT);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_IP_REG,
+ IT66121_AFE_IP_EC1, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_XP_EC1_REG,
+ IT66121_AFE_XP_EC1_LOWCLK, 0x80);
+ if (ret)
+ return ret;
+ } else {
+ ret = regmap_write_bits(itb->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(itb->regmap, IT66121_AFE_IP_REG,
+ IT66121_AFE_IP_GAINBIT |
+ IT66121_AFE_IP_ER0,
+ IT66121_AFE_IP_ER0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_IP_REG,
+ IT66121_AFE_IP_EC1,
+ IT66121_AFE_IP_EC1);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->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(itb->regmap, IT66121_SW_RST_REG,
+ IT66121_SW_RST_REF | IT66121_SW_RST_VID, 0);
+ if (ret)
+ return ret;
+
+ return it66121_fire_afe(itb);
+}
+
+static inline int it66121_wait_ddc_ready(struct it66121_bridge *itb)
+{
+ u32 error = IT66121_DDC_STATUS_NOACK |
+ IT66121_DDC_STATUS_WAIT_BUS |
+ IT66121_DDC_STATUS_ARBI_LOSE;
+ u32 done = IT66121_DDC_STATUS_TX_DONE;
+ int ret, val;
+
+ ret = regmap_read_poll_timeout(itb->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_bridge *itb)
+{
+ unsigned int swreset, cpdesire;
+ int ret;
+
+ ret = regmap_read(itb->regmap, IT66121_SW_RST_REG, &swreset);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(itb->regmap, IT66121_HDCP_REG, &cpdesire);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_HDCP_REG,
+ cpdesire & (~IT66121_HDCP_CPDESIRED & 0xFF));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_SW_RST_REG,
+ (swreset | IT66121_SW_RST_HDCP));
+ if (ret)
+ return ret;
+
+ ret = it66121_preamble_ddc(itb);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_DDC_COMMAND_REG,
+ IT66121_DDC_COMMAND_ABORT);
+ if (ret)
+ return ret;
+
+ return it66121_wait_ddc_ready(itb);
+}
+
+static int it66121_get_edid_block(void *context,
+ u8 *buf,
+ unsigned int block,
+ size_t len)
+{
+ struct it66121_bridge *itb = (struct it66121_bridge *)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(itb->regmap, IT66121_DDC_COMMAND_REG,
+ IT66121_DDC_COMMAND_FIFO_CLR);
+ if (ret)
+ return ret;
+
+ ret = it66121_wait_ddc_ready(itb);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_DDC_OFFSET_REG, offset);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_DDC_BYTE_REG, cnt);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_DDC_SEGMENT_REG, block);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(itb->regmap, IT66121_DDC_COMMAND_REG,
+ IT66121_DDC_COMMAND_EDID_READ);
+ if (ret)
+ return ret;
+
+ offset += cnt;
+ remain -= cnt;
+
+ ret = it66121_wait_ddc_ready(itb);
+ if (ret) {
+ it66121_abort_ddc_ops(itb);
+ return ret;
+ }
+
+ ret = regmap_noinc_read(itb->regmap, IT66121_DDC_RD_FIFO_REG,
+ buf, cnt);
+ if (ret)
+ return ret;
+
+ buf += cnt;
+ }
+
+ return 0;
+}
+
+static bool it66121_is_hpd_detect(struct it66121_bridge *itb)
+{
+ int val;
+
+ if (regmap_read(itb->regmap, IT66121_SYS_STATUS_REG, &val))
+ return false;
+
+ return val & IT66121_SYS_STATUS_HPDETECT;
+}
+
+static int it66121_connector_get_modes(struct drm_connector *connector)
+{
+ struct it66121_bridge *itb = connector_to_it66121(connector);
+ u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+ int num_modes = 0;
+ struct edid *edid;
+ int ret;
+
+ edid = drm_bridge_get_edid(&itb->bridge, connector);
+ if (!edid) {
+ drm_err(connector->dev, "Failed to read EDID\n");
+ goto failed;
+ }
+
+ if (drm_connector_update_edid_property(connector, edid)) {
+ drm_err(connector->dev, "Failed to update EDID\n");
+ goto failed;
+ }
+
+ ret = drm_display_info_set_bus_formats(&connector->display_info,
+ &bus_format, 1);
+ if (ret)
+ goto failed;
+
+ num_modes = drm_add_edid_modes(connector, edid);
+
+failed:
+ return num_modes;
+}
+
+static int it66121_connector_detect_ctx(struct drm_connector *connector,
+ struct drm_modeset_acquire_ctx *ctx,
+ bool force)
+{
+ struct it66121_bridge *itb = connector_to_it66121(connector);
+
+ return it66121_is_hpd_detect(itb) ? connector_status_connected
+ : connector_status_disconnected;
+}
+
+static struct drm_connector_helper_funcs it66121_connector_helper_funcs = {
+ .get_modes = it66121_connector_get_modes,
+ .detect_ctx = it66121_connector_detect_ctx,
+};
+
+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_connector_init(struct drm_bridge *bridge)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+ struct drm_connector *connector = &itb->connector;
+ int ret;
+
+ if (bridge->ops & DRM_BRIDGE_OP_HPD) {
+ connector->polled = DRM_CONNECTOR_POLL_HPD;
+ } else {
+ connector->polled = DRM_CONNECTOR_POLL_CONNECT |
+ DRM_CONNECTOR_POLL_DISCONNECT;
+ }
+
+ ret = drm_connector_init(bridge->dev,
+ connector,
+ &it66121_connector_funcs,
+ bridge->type);
+ if (ret)
+ return ret;
+
+ drm_connector_helper_add(connector, &it66121_connector_helper_funcs);
+
+ drm_connector_attach_encoder(connector, bridge->encoder);
+
+ return 0;
+}
+
+static int it66121_bridge_attach(struct drm_bridge *bridge,
+ enum drm_bridge_attach_flags flags)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+ int ret;
+
+ ret = it66121_bridge_connector_init(bridge);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_CLK_BANK_REG,
+ IT66121_CLK_BANK_PWROFF_RCLK, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_INT_REG,
+ IT66121_INT_TX_CLK_OFF, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_DRV_REG,
+ IT66121_AFE_DRV_PWD, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_XP_REG,
+ IT66121_AFE_XP_PWDI | IT66121_AFE_XP_PWDPLL, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_IP_REG,
+ IT66121_AFE_IP_PWDPLL, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_DRV_REG,
+ IT66121_AFE_DRV_RST, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_XP_REG,
+ IT66121_AFE_XP_RESETB, IT66121_AFE_XP_RESETB);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_AFE_IP_REG,
+ IT66121_AFE_IP_RESETB, IT66121_AFE_IP_RESETB);
+ if (ret)
+ return ret;
+
+ ret = regmap_write_bits(itb->regmap, IT66121_SW_RST_REG,
+ IT66121_SW_RST_REF,
+ IT66121_SW_RST_REF);
+ if (ret)
+ return ret;
+
+ drm_info(bridge->dev,
+ "IT66121 attached, Vendor ID: 0x%x, Device ID: 0x%x\n",
+ itb->vendor_id, itb->device_id);
+
+ /* Per programming manual, sleep here for bridge to settle */
+ msleep(50);
+
+ return 0;
+}
+
+static void it66121_bridge_enable(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+ struct regmap *regmap = itb->regmap;
+ int ret;
+
+ ret = regmap_clear_bits(regmap, IT66121_AVMUTE_REG, IT66121_AVMUTE_BIT);
+ if (ret)
+ drm_err(bridge->dev, "Enable it66121 bridge failed");
+
+ regmap_write(regmap, IT66121_PKT_GEN_CTRL_REG,
+ IT66121_PKT_GEN_CTRL_ON | IT66121_PKT_GEN_CTRL_RPT);
+}
+
+static void it66121_bridge_disable(struct drm_bridge *bridge,
+ struct drm_bridge_state *bridge_state)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+ struct regmap *regmap = itb->regmap;
+ int ret;
+
+ ret = regmap_set_bits(regmap, IT66121_AVMUTE_REG, IT66121_AVMUTE_BIT);
+ if (ret)
+ drm_err(bridge->dev, "Disable it66121 bridge failed");
+
+ regmap_write(regmap, IT66121_PKT_GEN_CTRL_REG,
+ IT66121_PKT_GEN_CTRL_ON | IT66121_PKT_GEN_CTRL_RPT);
+}
+
+static void it66121_bridge_mode_set(struct drm_bridge *bridge,
+ const struct drm_display_mode *mode,
+ const struct drm_display_mode *adj_mode)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+ struct hdmi_avi_infoframe avi_infoframe;
+ u8 av_buf[HDMI_INFOFRAME_SIZE(AVI)];
+ int ret;
+
+ mutex_lock(&itb->lock);
+
+ hdmi_avi_infoframe_init(&avi_infoframe);
+
+ ret = drm_hdmi_avi_infoframe_from_display_mode(&avi_infoframe,
+ &itb->connector,
+ adj_mode);
+ if (ret) {
+ drm_err(bridge->dev, "Failed to setup AVI infoframe\n");
+ goto unlock;
+ }
+
+ ret = hdmi_avi_infoframe_pack(&avi_infoframe, av_buf, sizeof(av_buf));
+ if (ret < 0) {
+ drm_err(bridge->dev, "Failed to pack infoframe\n");
+ goto unlock;
+ }
+
+ /* Write new AVI infoframe packet */
+ ret = regmap_bulk_write(itb->regmap, IT66121_AVIINFO_DB1_REG,
+ &av_buf[HDMI_INFOFRAME_HEADER_SIZE],
+ HDMI_AVI_INFOFRAME_SIZE);
+ if (ret)
+ goto unlock;
+
+ if (regmap_write(itb->regmap, IT66121_AVIINFO_CSUM_REG, av_buf[3]))
+ goto unlock;
+
+ /* Enable AVI infoframe */
+ if (regmap_write(itb->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(itb->regmap, IT66121_HDMI_MODE_REG, IT66121_HDMI_MODE_HDMI))
+ goto unlock;
+
+ if (regmap_write_bits(itb->regmap, IT66121_CLK_BANK_REG,
+ IT66121_CLK_BANK_PWROFF_TXCLK,
+ IT66121_CLK_BANK_PWROFF_TXCLK))
+ goto unlock;
+
+ if (it66121_configure_input(itb))
+ goto unlock;
+
+ if (it66121_configure_afe(itb, adj_mode))
+ goto unlock;
+
+ if (regmap_write_bits(itb->regmap, IT66121_CLK_BANK_REG,
+ IT66121_CLK_BANK_PWROFF_TXCLK, 0))
+ goto unlock;
+
+unlock:
+ mutex_unlock(&itb->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)
+{
+ if (mode->clock > 148500)
+ return MODE_CLOCK_HIGH;
+
+ if (mode->clock < 25000)
+ return MODE_CLOCK_LOW;
+
+ return MODE_OK;
+}
+
+static struct edid *it66121_bridge_get_edid(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+ struct edid *edid;
+ int ret;
+
+ mutex_lock(&itb->lock);
+ ret = it66121_preamble_ddc(itb);
+ if (ret) {
+ edid = NULL;
+ goto unlock;
+ }
+
+ ret = regmap_write(itb->regmap, IT66121_DDC_HEADER_REG,
+ IT66121_DDC_HEADER_EDID);
+ if (ret) {
+ edid = NULL;
+ goto unlock;
+ }
+
+ edid = drm_do_get_edid(connector, it66121_get_edid_block, itb);
+
+unlock:
+ mutex_unlock(&itb->lock);
+
+ return edid;
+}
+
+static void it66121_bridge_detach(struct drm_bridge *bridge)
+{
+ struct it66121_bridge *itb = bridge_to_it66121(bridge);
+
+ mutex_destroy(&itb->lock);
+
+ i2c_unregister_device(itb->client);
+
+ drm_bridge_remove(bridge);
+}
+
+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,
+ .detach = it66121_bridge_detach,
+ .atomic_enable = it66121_bridge_enable,
+ .atomic_disable = it66121_bridge_disable,
+ .mode_set = it66121_bridge_mode_set,
+ .mode_valid = it66121_bridge_mode_valid,
+ .get_edid = it66121_bridge_get_edid,
+};
+
+static void it66121_bridge_get_version(struct it66121_bridge *itb)
+{
+ u32 vendor_ids[2] = { 0 };
+ u32 device_ids[2] = { 0 };
+
+ regmap_read(itb->regmap, IT66121_VENDOR_ID0_REG, &vendor_ids[0]);
+ regmap_read(itb->regmap, IT66121_VENDOR_ID1_REG, &vendor_ids[1]);
+ regmap_read(itb->regmap, IT66121_DEVICE_ID0_REG, &device_ids[0]);
+ regmap_read(itb->regmap, IT66121_DEVICE_ID1_REG, &device_ids[1]);
+
+ /* Revision is shared with DEVICE_ID1 */
+ itb->revision = FIELD_GET(IT66121_REVISION_MASK, device_ids[1]);
+ device_ids[1] &= IT66121_DEVICE_ID1_MASK;
+
+ itb->vendor_id = vendor_ids[1] << 8 | vendor_ids[0];
+ itb->device_id = device_ids[1] << 8 | device_ids[0];
+}
+
+static void it66121_bridge_init_base(struct it66121_bridge *itb, bool hpd)
+{
+ struct drm_bridge *bridge = &itb->bridge;
+
+ bridge->funcs = &it66121_bridge_funcs;
+ bridge->type = DRM_MODE_CONNECTOR_HDMIA;
+ bridge->ops = DRM_BRIDGE_OP_EDID;
+
+ if (hpd)
+ bridge->ops |= DRM_BRIDGE_OP_HPD;
+
+ drm_bridge_add(bridge);
+}
+
+/*
+ * The device address is 0x98 if PCADR pin is pulled low, 0x98 >> 1 = 0x4c
+ * The device address is 0x9A if PCADR pin is pulled high, 0x9A >> 1 = 0x4d
+ */
+static bool it66121_probe_slave(struct drm_device *ddev,
+ struct i2c_adapter *adapter,
+ u8 *addr)
+{
+ struct i2c_msg msg = {
+ .len = 0,
+ };
+ int num = 3;
+ int count;
+ int i;
+
+ /* Try slave address 0x4c */
+ msg.addr = 0x4c;
+ count = 0;
+ for (i = 0; i < num; i++) {
+ count += i2c_transfer(adapter, &msg, 1);
+ udelay(9);
+ }
+
+ if (count == num) {
+ *addr = 0x4c;
+ return true;
+ }
+
+ /* Try slave address 0x4d */
+ msg.addr = 0x4d;
+ count = 0;
+ for (i = 0; i < num; i++) {
+ count += i2c_transfer(adapter, &msg, 1);
+ udelay(9);
+ }
+
+ if (count == num) {
+ *addr = 0x4d;
+ return true;
+ }
+
+ drm_err(ddev, "No reliable slave i2c device found\n");
+
+ /*
+ * If no reliable slave i2c device found, we would like drop the
+ * support.
+ */
+ return false;
+}
+
+struct drm_bridge *it66121_bridge_create(struct drm_device *ddev,
+ struct i2c_adapter *i2c,
+ u8 addr,
+ bool enable_hpd,
+ u32 int_gpio,
+ unsigned int pipe)
+{
+ struct i2c_board_info it66121_board_info = {
+ .type = IT66121_CHIP_NAME,
+ };
+ struct it66121_bridge *itb;
+ struct i2c_client *client;
+ u8 addr_probed;
+
+ if (!it66121_probe_slave(ddev, i2c, &addr_probed))
+ return NULL;
+
+ if (addr != addr_probed) {
+ drm_warn(ddev, "device address(0x%x) is not correct\n", addr);
+ addr = addr_probed;
+ }
+
+ it66121_board_info.addr = addr;
+
+ itb = devm_kzalloc(ddev->dev, sizeof(*itb), GFP_KERNEL);
+ if (!itb)
+ return NULL;
+
+ client = i2c_new_client_device(i2c, &it66121_board_info);
+ if (IS_ERR(client))
+ return NULL;
+
+ drm_info(ddev, "i2c client %s@0x%02x created\n",
+ it66121_board_info.type, it66121_board_info.addr);
+
+ itb->client = client;
+
+ i2c_set_clientdata(client, itb);
+
+ mutex_init(&itb->lock);
+
+ itb->regmap = devm_regmap_init_i2c(client, &it66121_regmap_config);
+ if (IS_ERR(itb->regmap)) {
+ drm_err(ddev, "Failed to map registers\n");
+ return NULL;
+ }
+
+ it66121_bridge_get_version(itb);
+
+ it66121_bridge_init_base(itb, enable_hpd);
+
+ return &itb->bridge;
+}
diff --git a/drivers/gpu/drm/loongson/ite_it66121.h b/drivers/gpu/drm/loongson/ite_it66121.h
new file mode 100644
index 000000000000..c3e26cce1b02
--- /dev/null
+++ b/drivers/gpu/drm/loongson/ite_it66121.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2023 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ITE_IT66121_H__
+#define __ITE_IT66121_H__
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_device.h>
+
+struct drm_bridge *it66121_bridge_create(struct drm_device *ddev,
+ struct i2c_adapter *i2c,
+ u8 addr,
+ bool enable_hpd,
+ u32 int_gpio,
+ unsigned int pipe);
+
+#endif
diff --git a/drivers/gpu/drm/loongson/ite_it66121_regs.h b/drivers/gpu/drm/loongson/ite_it66121_regs.h
new file mode 100644
index 000000000000..57118a4501c1
--- /dev/null
+++ b/drivers/gpu/drm/loongson/ite_it66121_regs.h
@@ -0,0 +1,268 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+/*
+ * Copyright (C) 2020 BayLibre, SAS
+ * Author: Phong LE <ple@xxxxxxxxxxxx>
+ * Copyright (C) 2018-2019, Artem Mygaiev
+ * Copyright (C) 2017, Fresco Logic, Incorporated.
+ */
+
+#ifndef __ITE_IT66121_h__
+#define __ITE_IT66121_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_RGB888 (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_AVMUTE_REG 0xC1
+#define IT66121_AVMUTE_BIT BIT(0)
+#define IT66121_AVMUTE_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 */
+
+#endif
--
2.34.1