[PATCH v2 0/2] usb: typec: ucsi: Add ITE IT527x/IT885x and DisplayPort alt mode support

[PATCH v2 0/2] usb: typec: ucsi: Add ITE IT527x/IT885x and DisplayPort alt mode support

[Amber Kao]

This series extends the itepd UCSI driver with support for more ITE
Type-C PD controllers, and adds DisplayPort alternate mode handling.

The IT527x series and the IT8855, IT8856 and IT8857 run the same UCSI
firmware codebase as the IT8851 and are software compatible with it, so
they are described as fallbacks to "ite,it8851". The IT8853, IT8856,
IT8857, IT5272 and IT5274 drive two Type-C connectors, the other
variants drive one.

For DisplayPort alternate mode, the driver queries the current
alternate mode from the PPM, configures the Type-C mux and retimer
accordingly, and reports HPD state and HPD IRQ through the DRM
auxiliary HPD bridge.

This series depends on the following series, which has not been picked
up yet:

  https://lore.kernel.org/linux-usb/20260807-ucsi-itepd-v7-0-998ac11ed0ef@ite.com.tw/

Signed-off-by: Amber Kao <ite_pd@ite.com.tw>
---
Changes in v2:
- dt-bindings: drop the second example, it only differs by the
  compatible string.
- dt-bindings: express the IT527x series, IT8853 and IT885[5-7] as
  fallbacks to "ite,it8851"; all parts run the same UCSI firmware
  codebase, so the driver needs no per-part handling.
- dt-bindings: add IT8855, IT8856 and IT8857.
- dt-bindings: move the variant description out of the 'compatible'
  property and shorten it.
- dt-bindings: fix indentation in the existing example.
- driver: drop the "ite,it5271" of_device_id entry, now covered by the
  fallback.
- driver: update MODULE_DESCRIPTION and the Kconfig prompt to cover the
  IT885x and IT527x series.
- Link to v1: https://patch.msgid.link/20260911-ucsi-itepd-it527x-v1-0-14c8041afb53@ite.com.tw

To: Amber Kao <amber.kao@ite.com.tw>
To: Jeson Yang <jeson.yang@ite.com.tw>
To: Yaode Fang <Yaode.Fang@ite.com.tw>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: linux-usb@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

---
Amber Kao (2):
      dt-bindings: usb: ite,it8851: Add IT527x and IT885x series support
      usb: typec: ucsi: itepd: Add DisplayPort alternate mode support

 .../devicetree/bindings/usb/ite,it8851.yaml        |  49 ++-
 drivers/usb/typec/ucsi/Kconfig                     |   8 +-
 drivers/usb/typec/ucsi/ucsi_itepd.c                | 404 ++++++++++++++++++++-
 3 files changed, 435 insertions(+), 26 deletions(-)
---
base-commit: a8092db1cf4c3fd6cad36c5a10dcaa60d95ef114
change-id: 20260911-ucsi-itepd-it527x-5b87a61a71bb

Best regards,
--  
Amber Kao <ite_pd@ite.com.tw>

[PATCH v2 1/2] dt-bindings: usb: ite,it8851: Add IT527x and IT885x series support

[Amber Kao]

Add compatible strings for the ITE IT527x series and for the IT8855,
IT8856 and IT8857. All parts run the same UCSI firmware codebase as the
IT8851 and are software compatible with it, so they are described as
fallbacks to "ite,it8851".

The IT8853, IT8856, IT8857, IT5272 and IT5274 drive two Type-C
connectors, the other variants drive one.

Signed-off-by: Amber Kao <ite_pd@ite.com.tw>
---
 .../devicetree/bindings/usb/ite,it8851.yaml        | 49 +++++++++++++++-------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/ite,it8851.yaml b/Documentation/devicetree/bindings/usb/ite,it8851.yaml
index defd431aba97..a44da61ef24d 100644
--- a/Documentation/devicetree/bindings/usb/ite,it8851.yaml
+++ b/Documentation/devicetree/bindings/usb/ite,it8851.yaml
@@ -4,22 +4,36 @@
 $id: http://devicetree.org/schemas/usb/ite,it8851.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: ITE IT8851/IT8853 USB Type-C Power Delivery Controller
+title: ITE USB Type-C Power Delivery Controllers
 
 maintainers:
   - Jeson Yang <jeson.yang@ite.com.tw>
-  - Amber Kao <amber.kao@ite.com.tw>
-description:
-  The ITE IT8851 is an I2C-based USB Type-C Power Delivery (PD) controller
-  supporting one Type-C port.
-  The IT8853 is the two-port variant sharing the same programming interface.
+
+description: |
+  ITE IT885x and IT527x I2C-based USB Type-C Power Delivery controllers.
+  The later parts are software compatible with the IT8851 and use it as a
+  fallback.
+
+  The IT885x family covers the IT8851, IT8853, IT8855, IT8856 and IT8857.
+  The IT527x family covers the IT5271, IT5272, IT5273 and IT5274.
+
+  The IT8853, IT8856, IT8857, IT5272 and IT5274 drive two Type-C
+  connectors, the other variants drive one.
 
 properties:
   compatible:
     oneOf:
       - const: ite,it8851
       - items:
-          - const: ite,it8853
+          - enum:
+              - ite,it5271
+              - ite,it5272
+              - ite,it5273
+              - ite,it5274
+              - ite,it8853
+              - ite,it8855
+              - ite,it8856
+              - ite,it8857
           - const: ite,it8851
 
   reg:
@@ -63,7 +77,12 @@ allOf:
         properties:
           compatible:
             contains:
-              const: ite,it8853
+              enum:
+                - ite,it5272
+                - ite,it5274
+                - ite,it8853
+                - ite,it8856
+                - ite,it8857
     then:
       properties:
         connector@1: false
@@ -101,21 +120,21 @@ examples:
                     port@0 {
                         reg = <0>;
                         endpoint {
-                            remote-endpoint = <&eud_con>;
+                            remote-endpoint = <&usb0_hs_con>;
                         };
                     };
 
                     port@1 {
                         reg = <1>;
                         endpoint {
-                            remote-endpoint = <&redriver_ss_out>;
+                            remote-endpoint = <&redriver0_ss_out>;
                         };
                     };
 
                     port@2 {
                         reg = <2>;
                         endpoint {
-                            remote-endpoint = <&fsa4480_sbu_mux>;
+                            remote-endpoint = <&sbu_mux0>;
                         };
                     };
                 };
@@ -135,19 +154,21 @@ examples:
                     port@0 {
                         reg = <0>;
                         endpoint {
-                          remote-endpoint = <&usb1_hs_con>;
+                            remote-endpoint = <&usb1_hs_con>;
                         };
                     };
+
                     port@1 {
                         reg = <1>;
                         endpoint {
-                          remote-endpoint = <&redriver1_ss_out>;
+                            remote-endpoint = <&redriver1_ss_out>;
                         };
                     };
+
                     port@2 {
                         reg = <2>;
                         endpoint {
-                          remote-endpoint = <&sbu_mux1>;
+                            remote-endpoint = <&sbu_mux1>;
                         };
                     };
                 };

-- 
2.53.0

[PATCH v2 2/2] usb: typec: ucsi: itepd: Add DisplayPort alternate mode support

[Amber Kao]

Add support for DisplayPort alternate mode. The driver retrieves
the current alternate mode from the PPM, configures the Type-C mux
and retimer accordingly, and reports HPD state and HPD IRQ events
through the DRM auxiliary HPD bridge.

Signed-off-by: Amber Kao <ite_pd@ite.com.tw>
---
 drivers/usb/typec/ucsi/Kconfig      |   8 +-
 drivers/usb/typec/ucsi/ucsi_itepd.c | 404 +++++++++++++++++++++++++++++++++++-
 2 files changed, 400 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index 0f10dac9b34b..c5eaf4967e4e 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -105,11 +105,15 @@ config UCSI_HUAWEI_GAOKUN
 	  called ucsi_huawei_gaokun.
 
 config UCSI_ITEPD
-	tristate "UCSI Interface Driver for ITE IT8851/IT8853"
+	tristate "UCSI Interface Driver for ITE IT885x and IT527x series"
 	depends on I2C
+	depends on DRM || !DRM
+	select DRM_AUX_HPD_BRIDGE if DRM_BRIDGE && OF
 	help
 	  This driver enables UCSI support on platforms that expose an
-	  ITE IT8851/IT8853 Type-C Power Delivery controller over an I2C interface.
+	  ITE IT885x or IT527x series Type-C Power Delivery controller
+	  over an I2C interface. It also supports DisplayPort alternate
+	  mode, including HPD notification through the DRM bridge.
 
 	  To compile the driver as a module, choose M here: the module
 	  will be called ucsi_itepd.
diff --git a/drivers/usb/typec/ucsi/ucsi_itepd.c b/drivers/usb/typec/ucsi/ucsi_itepd.c
index 50a9eae656ab..8c4e9c1bd06f 100644
--- a/drivers/usb/typec/ucsi/ucsi_itepd.c
+++ b/drivers/usb/typec/ucsi/ucsi_itepd.c
@@ -3,14 +3,24 @@
  * Copyright (C) 2025-2026, ITE. All Rights Reserved
  *
  */
+#include <linux/auxiliary_bus.h>
+#include <linux/bitmap.h>
 #include <linux/bits.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/unaligned.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_retimer.h>
+
+#include <drm/bridge/aux-bridge.h>
 
 #include "ucsi.h"
 
@@ -29,6 +39,35 @@
 #define ITEPD_EVENT_NONE	0
 #define ITEPD_EVENT_UCSI	1
 #define ITEPD_EVENT_VDM		2
+#define ITEPD_EVENT_OTHER	3
+
+#define ITEPD_CONSTAT_ORIENTATION_OFFSET	86
+
+#define ITEPD_CAM_CS_INDEX(_i_)			((u64)(_i_) << 24)
+#define ITEPD_CAM_CS_LEN			10
+#define ITEPD_CAM_CS_STATUS_OFFSET		1
+#define ITEPD_CAM_CS_CONF_OFFSET		6
+
+#define ITEPD_CAM_NONE				0xff
+
+#define ITEPD_ATTENTION_VDO_LEN			11
+#define ITEPD_ATTENTION_NUM_VDOS_OFFSET		2
+#define ITEPD_ATTENTION_NUM_VDOS_MASK		GENMASK(2, 0)
+#define ITEPD_ATTENTION_VDO_OFFSET		7
+
+struct itepd;
+
+struct itepd_port {
+	struct itepd *itepd;
+	unsigned int index;
+	struct typec_mux *typec_mux;
+	struct typec_retimer *typec_retimer;
+	struct auxiliary_device *bridge;
+	struct typec_mux_state state;
+	struct typec_altmode dp_alt;
+	unsigned long mode;
+	bool hpd_state;
+};
 
 struct itepd {
 	struct i2c_client *client;
@@ -38,6 +77,9 @@ struct itepd {
 	struct mutex received_lock;	/* Protects cci and msg_in */
 	u8 msg_in[ITEPD_MSG_IN_MAX_LEN];
 	u32 cci;
+
+	struct itepd_port *ports;
+	unsigned int num_ports;
 };
 
 static u8 ucsi_itepd_get_len(u32 cci)
@@ -115,25 +157,26 @@ static int itepd_process_event(struct itepd *itepd, u32 *cci)
 {
 	u8 msg_in[ITEPD_MSG_IN_MAX_LEN] = {};
 	__le32 le_cci;
-	u8 event, ack;
+	u8 raw, event, ack;
 	u8 len = 0;
 	int err = 0;
 	int ret;
 
 	guard(mutex)(&itepd->event_lock);
 
-	ret = itepd_read_reg(itepd, ITEPD_VENDOR_INT, &event, sizeof(event));
+	ret = itepd_read_reg(itepd, ITEPD_VENDOR_INT, &raw, sizeof(raw));
 	if (ret)
 		return ret;
 
-	event &= ITEPD_ALERT_VDM_EVENT | ITEPD_ALERT_UCSI_EVENT;
-	if (!event) {
+	if (!raw) {
 		mutex_lock(&itepd->received_lock);
 		*cci = itepd->cci;
 		mutex_unlock(&itepd->received_lock);
 		return ITEPD_EVENT_NONE;
 	}
 
+	event = raw & (ITEPD_ALERT_VDM_EVENT | ITEPD_ALERT_UCSI_EVENT);
+
 	if (event & ITEPD_ALERT_UCSI_EVENT) {
 		err = itepd_read_reg(itepd, ITEPD_UCSI_CCI_REG, &le_cci,
 				     sizeof(le_cci));
@@ -148,7 +191,7 @@ static int itepd_process_event(struct itepd *itepd, u32 *cci)
 		}
 	}
 
-	ack = event;
+	ack = raw;
 	ret = itepd_write_reg(itepd, ITEPD_VENDOR_WC_INT, &ack, sizeof(ack));
 	if (ret)
 		return ret;
@@ -169,7 +212,8 @@ static int itepd_process_event(struct itepd *itepd, u32 *cci)
 	*cci = itepd->cci;
 	mutex_unlock(&itepd->received_lock);
 
-	return ITEPD_EVENT_VDM;
+	return event & ITEPD_ALERT_VDM_EVENT ? ITEPD_EVENT_VDM :
+					       ITEPD_EVENT_OTHER;
 }
 
 static int ucsi_itepd_read_version(struct ucsi *ucsi, u16 *version)
@@ -220,18 +264,233 @@ static int ucsi_itepd_read_message_in(struct ucsi *ucsi, void *val, size_t val_l
 static int ucsi_itepd_async_control(struct ucsi *ucsi, u64 command)
 {
 	struct itepd *itepd = ucsi_get_drvdata(ucsi);
-	__le64 le_cmd = cpu_to_le64(command);
+	__le64 le_cmd;
 
-	if (UCSI_COMMAND(command) == UCSI_PPM_RESET) {
+	switch (UCSI_COMMAND(command)) {
+	case UCSI_PPM_RESET:
 		mutex_lock(&itepd->received_lock);
 		itepd->cci = 0;
 		mutex_unlock(&itepd->received_lock);
+		break;
+	case UCSI_SET_NOTIFICATION_ENABLE:
+		command |= UCSI_ENABLE_NTFY_ATTENTION;
+		break;
+	default:
+		break;
 	}
 
+	le_cmd = cpu_to_le64(command);
+
 	return itepd_write_reg(itepd, ITEPD_UCSI_CONTROL_REG, &le_cmd,
 			       sizeof(le_cmd));
 }
 
+static void itepd_port_set_state(struct itepd_port *port, unsigned long mode,
+				 struct typec_displayport_data *dp_data)
+{
+	struct device *dev = &port->itepd->client->dev;
+	struct typec_retimer_state retimer_state = {};
+	int ret;
+
+	if (!dp_data && mode == port->mode)
+		return;
+
+	port->dp_alt.active = !!dp_data;
+
+	port->state.alt = dp_data ? &port->dp_alt : NULL;
+	port->state.mode = mode;
+	port->state.data = dp_data;
+
+	retimer_state.alt = port->state.alt;
+	retimer_state.mode = mode;
+	retimer_state.data = dp_data;
+
+	ret = typec_retimer_set(port->typec_retimer, &retimer_state);
+	if (ret)
+		dev_err(dev, "port%u: failed to set retimer to mode %lu: %d\n",
+			port->index, mode, ret);
+
+	ret = typec_mux_set(port->typec_mux, &port->state);
+	if (ret)
+		dev_err(dev, "port%u: failed to set mux to mode %lu: %d\n",
+			port->index, mode, ret);
+
+	port->mode = mode;
+
+	port->state.data = NULL;
+}
+
+static void itepd_port_notify_hpd(struct itepd_port *port, bool hpd_state,
+				  bool hpd_irq)
+{
+	if (!port->bridge)
+		return;
+
+	if (hpd_state == port->hpd_state && !hpd_irq)
+		return;
+
+	port->hpd_state = hpd_state;
+
+	drm_aux_hpd_bridge_notify(&port->bridge->dev,
+				  hpd_state ? connector_status_connected :
+					      connector_status_disconnected);
+}
+
+static void itepd_set_orientation(struct ucsi_connector *con)
+{
+	if (con->ucsi->version >= UCSI_VERSION_2_0)
+		return;
+
+	if (!UCSI_CONSTAT(con, CONNECTED)) {
+		typec_set_orientation(con->port, TYPEC_ORIENTATION_NONE);
+		return;
+	}
+
+	if (bitmap_read(con->status, ITEPD_CONSTAT_ORIENTATION_OFFSET, 1) ==
+	    UCSI_CONSTAT_ORIENTATION_REVERSE)
+		typec_set_orientation(con->port, TYPEC_ORIENTATION_REVERSE);
+	else
+		typec_set_orientation(con->port, TYPEC_ORIENTATION_NORMAL);
+}
+
+static int itepd_get_dp_cam(struct itepd *itepd, struct ucsi_connector *con)
+{
+	struct ucsi_altmode alt[2] = {};
+	u64 cmd;
+	u8 cam;
+	int ret;
+
+	cmd = UCSI_GET_CURRENT_CAM | UCSI_CONNECTOR_NUMBER(con->num);
+	ret = ucsi_send_command(itepd->ucsi, cmd, &cam, sizeof(cam));
+	if (ret < 0)
+		return ret;
+
+	if (cam == ITEPD_CAM_NONE)
+		return -ENODEV;
+
+	cmd = UCSI_GET_ALTERNATE_MODES;
+	cmd |= UCSI_GET_ALTMODE_RECIPIENT(UCSI_RECIPIENT_CON);
+	cmd |= UCSI_GET_ALTMODE_CONNECTOR_NUMBER(con->num);
+	cmd |= UCSI_GET_ALTMODE_OFFSET(cam);
+	ret = ucsi_send_command(itepd->ucsi, cmd, alt, sizeof(alt));
+	if (ret < 0) {
+		dev_dbg(&itepd->client->dev, "con%d: cannot verify CAM %u: %d\n",
+			con->num, cam, ret);
+		return cam;
+	}
+
+	if (alt[0].svid != USB_TYPEC_DP_SID)
+		return -ENODEV;
+
+	return cam;
+}
+
+static int itepd_get_attention_status(struct itepd *itepd,
+				      struct ucsi_connector *con, u32 *status)
+{
+	u8 data[ITEPD_ATTENTION_VDO_LEN] = {};
+	u64 cmd;
+	int ret;
+
+	cmd = UCSI_GET_ATTENTION_VDO | UCSI_CONNECTOR_NUMBER(con->num);
+	ret = ucsi_send_command(itepd->ucsi, cmd, data, sizeof(data));
+	if (ret < 0)
+		return ret;
+
+	if (!(data[ITEPD_ATTENTION_NUM_VDOS_OFFSET] &
+	      ITEPD_ATTENTION_NUM_VDOS_MASK))
+		return -ENODATA;
+
+	*status = get_unaligned_le32(data + ITEPD_ATTENTION_VDO_OFFSET);
+
+	return 0;
+}
+
+static void itepd_handle_dp_altmode(struct itepd *itepd,
+				    struct itepd_port *port,
+				    struct ucsi_connector *con)
+{
+	struct typec_displayport_data dp_data = {};
+	u8 data[ITEPD_CAM_CS_LEN] = {};
+	unsigned long mode;
+	u32 status;
+	u8 pin_assign;
+	u64 cmd;
+	int cam;
+	int ret;
+
+	cam = itepd_get_dp_cam(itepd, con);
+	if (cam < 0) {
+		/* Partner is in some other alternate mode, keep USB alive */
+		itepd_port_set_state(port, TYPEC_STATE_USB, NULL);
+		itepd_port_notify_hpd(port, false, false);
+		return;
+	}
+
+	cmd = UCSI_GET_CAM_CS | UCSI_CONNECTOR_NUMBER(con->num) |
+	      ITEPD_CAM_CS_INDEX(cam);
+	ret = ucsi_send_command(itepd->ucsi, cmd, data, sizeof(data));
+	if (ret < 0) {
+		dev_err(&itepd->client->dev, "con%d: GET_CAM_CS failed: %d\n",
+			con->num, ret);
+		return;
+	}
+
+	dp_data.status = get_unaligned_le32(data + ITEPD_CAM_CS_STATUS_OFFSET);
+	dp_data.conf = get_unaligned_le32(data + ITEPD_CAM_CS_CONF_OFFSET);
+
+	pin_assign = DP_CONF_GET_PIN_ASSIGN(dp_data.conf);
+	if (pin_assign)
+		mode = TYPEC_MODAL_STATE(get_count_order(pin_assign));
+	else
+		mode = TYPEC_STATE_SAFE;
+
+	itepd_port_set_state(port, mode, &dp_data);
+
+	if (!itepd_get_attention_status(itepd, con, &status))
+		dp_data.status = status;
+
+	itepd_port_notify_hpd(port, !!(dp_data.status & DP_STATUS_HPD_STATE),
+			      !!(dp_data.status & DP_STATUS_IRQ_HPD));
+}
+
+static void ucsi_itepd_update_connector(struct ucsi_connector *con)
+{
+	struct itepd *itepd = ucsi_get_drvdata(con->ucsi);
+
+	if (con->num < 1 || con->num > itepd->num_ports)
+		return;
+
+	con->typec_cap.orientation_aware = true;
+}
+
+static void ucsi_itepd_connector_status(struct ucsi_connector *con)
+{
+	struct itepd *itepd = ucsi_get_drvdata(con->ucsi);
+	struct itepd_port *port;
+
+	if (con->num < 1 || con->num > itepd->num_ports)
+		return;
+
+	port = &itepd->ports[con->num - 1];
+
+	itepd_set_orientation(con);
+
+	if (!UCSI_CONSTAT(con, CONNECTED)) {
+		itepd_port_set_state(port, TYPEC_STATE_SAFE, NULL);
+		itepd_port_notify_hpd(port, false, false);
+		return;
+	}
+
+	if (!UCSI_CONSTAT(con, PARTNER_FLAG_ALT_MODE)) {
+		itepd_port_set_state(port, TYPEC_STATE_USB, NULL);
+		itepd_port_notify_hpd(port, false, false);
+		return;
+	}
+
+	itepd_handle_dp_altmode(itepd, port, con);
+}
+
 static const struct ucsi_operations ucsi_itepd_ops = {
 	.read_version		= ucsi_itepd_read_version,
 	.read_cci		= ucsi_itepd_read_cci,
@@ -239,6 +498,8 @@ static const struct ucsi_operations ucsi_itepd_ops = {
 	.read_message_in	= ucsi_itepd_read_message_in,
 	.sync_control		= ucsi_sync_control_common,
 	.async_control		= ucsi_itepd_async_control,
+	.update_connector	= ucsi_itepd_update_connector,
+	.connector_status	= ucsi_itepd_connector_status,
 };
 
 static irqreturn_t itepd_irq_process(struct itepd *itepd)
@@ -256,6 +517,9 @@ static irqreturn_t itepd_irq_process(struct itepd *itepd)
 	if (ret == ITEPD_EVENT_UCSI)
 		ucsi_notify_common(itepd->ucsi, cci);
 
+	if (ret == ITEPD_EVENT_VDM)
+		dev_dbg(&itepd->client->dev, "VDM event\n");
+
 	return IRQ_HANDLED;
 }
 
@@ -266,6 +530,117 @@ static irqreturn_t itepd_irq_thread_fn(int irq, void *data)
 	return itepd_irq_process(itepd);
 }
 
+static void itepd_put_mux(void *data)
+{
+	typec_mux_put(data);
+}
+
+static void itepd_put_retimer(void *data)
+{
+	typec_retimer_put(data);
+}
+
+static int itepd_ports_init(struct itepd *itepd)
+{
+	struct device *dev = &itepd->client->dev;
+	struct itepd_port *port;
+	unsigned int count, idx = 0;
+	u32 reg;
+	int ret;
+
+	count = device_get_child_node_count(dev);
+	if (!count)
+		return 0;
+
+	itepd->ports = devm_kcalloc(dev, count, sizeof(*itepd->ports),
+				    GFP_KERNEL);
+	if (!itepd->ports)
+		return -ENOMEM;
+
+	device_for_each_child_node_scoped(dev, fwnode) {
+		ret = fwnode_property_read_u32(fwnode, "reg", &reg);
+		if (ret < 0)
+			return dev_err_probe(dev, ret,
+					     "%pfwP: missing reg property\n",
+					     fwnode);
+
+		if (reg != idx)
+			return dev_err_probe(dev, -EINVAL,
+					     "%pfwP: reg is %u, expected %u\n",
+					     fwnode, reg, idx);
+
+		port = &itepd->ports[idx];
+		port->itepd = itepd;
+		port->index = idx;
+		port->mode = TYPEC_STATE_SAFE;
+		port->state.mode = TYPEC_STATE_SAFE;
+		port->dp_alt.svid = USB_TYPEC_DP_SID;
+		port->dp_alt.mode = USB_TYPEC_DP_MODE;
+
+		port->typec_mux = fwnode_typec_mux_get(fwnode);
+		if (IS_ERR(port->typec_mux))
+			return dev_err_probe(dev, PTR_ERR(port->typec_mux),
+					     "port%u: failed to get mode-switch\n",
+					     idx);
+
+		if (port->typec_mux) {
+			ret = devm_add_action_or_reset(dev, itepd_put_mux,
+						       port->typec_mux);
+			if (ret)
+				return ret;
+		}
+
+		port->typec_retimer = fwnode_typec_retimer_get(fwnode);
+		if (IS_ERR(port->typec_retimer))
+			return dev_err_probe(dev, PTR_ERR(port->typec_retimer),
+					     "port%u: failed to get retimer-switch\n",
+					     idx);
+
+		if (port->typec_retimer) {
+			ret = devm_add_action_or_reset(dev, itepd_put_retimer,
+						       port->typec_retimer);
+			if (ret)
+				return ret;
+		}
+
+		if (is_of_node(fwnode)) {
+			struct device_node *np = to_of_node(fwnode);
+
+			port->bridge = devm_drm_dp_hpd_bridge_alloc(dev, np);
+			if (IS_ERR(port->bridge))
+				return dev_err_probe(dev, PTR_ERR(port->bridge),
+						     "port%u: failed to allocate HPD bridge\n",
+						     idx);
+		}
+
+		idx++;
+	}
+
+	itepd->num_ports = idx;
+
+	return 0;
+}
+
+static int itepd_bridges_add(struct itepd *itepd)
+{
+	struct device *dev = &itepd->client->dev;
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < itepd->num_ports; i++) {
+		if (!itepd->ports[i].bridge)
+			continue;
+
+		ret = devm_drm_dp_hpd_bridge_add(dev, itepd->ports[i].bridge);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "port%u: failed to add HPD bridge\n",
+					     i);
+	}
+
+	return 0;
+}
+
 static int itepd_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -286,6 +661,10 @@ static int itepd_probe(struct i2c_client *client)
 	mutex_init(&itepd->received_lock);
 	i2c_set_clientdata(client, itepd);
 
+	ret = itepd_ports_init(itepd);
+	if (ret)
+		return ret;
+
 	itepd->ucsi = ucsi_create(dev, &ucsi_itepd_ops);
 	if (IS_ERR(itepd->ucsi))
 		return dev_err_probe(dev, PTR_ERR(itepd->ucsi),
@@ -310,8 +689,14 @@ static int itepd_probe(struct i2c_client *client)
 		goto out_free_irq;
 	}
 
+	ret = itepd_bridges_add(itepd);
+	if (ret)
+		goto out_ucsi_unregister;
+
 	return 0;
 
+out_ucsi_unregister:
+	ucsi_unregister(itepd->ucsi);
 out_free_irq:
 	free_irq(client->irq, itepd);
 out_ucsi_destroy:
@@ -352,6 +737,5 @@ static struct i2c_driver itepd_driver = {
 module_i2c_driver(itepd_driver);
 
 MODULE_AUTHOR("Jeson Yang <jeson.yang@ite.com.tw>");
-MODULE_AUTHOR("Amber Kao <amber.kao@ite.com.tw>");
-MODULE_DESCRIPTION("UCSI driver for ITE IT8851 and IT8853 Type-C PD controllers");
+MODULE_DESCRIPTION("UCSI driver for ITE IT885x/IT527x Type-C PD controllers");
 MODULE_LICENSE("GPL");

-- 
2.53.0

Re: [PATCH v2 2/2] usb: typec: ucsi: itepd: Add DisplayPort alternate mode support

[Heikki Krogerus]

On Fri, Sep 18, 2026 at 06:03:44PM +0800, Amber Kao wrote:
> Add support for DisplayPort alternate mode. The driver retrieves
> the current alternate mode from the PPM, configures the Type-C mux
> and retimer accordingly, and reports HPD state and HPD IRQ events
> through the DRM auxiliary HPD bridge.
> 
> Signed-off-by: Amber Kao <ite_pd@ite.com.tw>
> ---
>  drivers/usb/typec/ucsi/Kconfig      |   8 +-
>  drivers/usb/typec/ucsi/ucsi_itepd.c | 404 +++++++++++++++++++++++++++++++++++-
>  2 files changed, 400 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> index 0f10dac9b34b..c5eaf4967e4e 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -105,11 +105,15 @@ config UCSI_HUAWEI_GAOKUN
>  	  called ucsi_huawei_gaokun.
>  
>  config UCSI_ITEPD
> -	tristate "UCSI Interface Driver for ITE IT8851/IT8853"
> +	tristate "UCSI Interface Driver for ITE IT885x and IT527x series"
>  	depends on I2C
> +	depends on DRM || !DRM
> +	select DRM_AUX_HPD_BRIDGE if DRM_BRIDGE && OF
>  	help
>  	  This driver enables UCSI support on platforms that expose an
> -	  ITE IT8851/IT8853 Type-C Power Delivery controller over an I2C interface.
> +	  ITE IT885x or IT527x series Type-C Power Delivery controller
> +	  over an I2C interface. It also supports DisplayPort alternate
> +	  mode, including HPD notification through the DRM bridge.

Please split this part into separate patch.

Thanks,

-- 
heikki

RE: [PATCH v2 2/2] usb: typec: ucsi: itepd: Add DisplayPort alternate mode support

[amber.kao]

On Fri, Sep 18, 2026 at XX:XX, Heikki Krogerus wrote:
> >  config UCSI_ITEPD
> > -	tristate "UCSI Interface Driver for ITE IT8851/IT8853"
> > +	tristate "UCSI Interface Driver for ITE IT885x and IT527x series"
> >  	depends on I2C
> > +	depends on DRM || !DRM
> > +	select DRM_AUX_HPD_BRIDGE if DRM_BRIDGE && OF
>
> Please split this part into separate patch.

Hi Heikki,

Understood, thanks for the suggestion.

I will move the Kconfig prompt, help text and MODULE_DESCRIPTION
updates out of the DisplayPort patch, so that the IT885x/IT527x
support and the DisplayPort alternate mode support are separate
patches.

Would it be fine to send both patches at the same time, or would you
prefer that I send the DisplayPort alternate mode support after the
IT885x/IT527x support has been accepted?

Thanks,
Amber

-----Original Message-----
From: Heikki Krogerus <heikki.krogerus@linux.intel.com> 
Sent: Tuesday, September 22, 2026 7:03 PM
To: ITE_PD <ite_pd@ite.com.tw>
Cc: Amber Kao (高鈺盈) <amber.kao@ite.com.tw>; Jeson Yang (楊志賢) <jeson.yang@ite.com.tw>; Yaode Fang (方耀德) <Yaode.Fang@ite.com.tw>; Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Rob Herring <robh@kernel.org>; Krzysztof Kozlowski <krzk+dt@kernel.org>; Conor Dooley <conor+dt@kernel.org>; linux-usb@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] usb: typec: ucsi: itepd: Add DisplayPort alternate mode support

On Fri, Sep 18, 2026 at 06:03:44PM +0800, Amber Kao wrote:
> Add support for DisplayPort alternate mode. The driver retrieves the 
> current alternate mode from the PPM, configures the Type-C mux and 
> retimer accordingly, and reports HPD state and HPD IRQ events through 
> the DRM auxiliary HPD bridge.
> 
> Signed-off-by: Amber Kao <ite_pd@ite.com.tw>
> ---
>  drivers/usb/typec/ucsi/Kconfig      |   8 +-
>  drivers/usb/typec/ucsi/ucsi_itepd.c | 404 
> +++++++++++++++++++++++++++++++++++-
>  2 files changed, 400 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/Kconfig 
> b/drivers/usb/typec/ucsi/Kconfig index 0f10dac9b34b..c5eaf4967e4e 
> 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -105,11 +105,15 @@ config UCSI_HUAWEI_GAOKUN
>  	  called ucsi_huawei_gaokun.
>  
>  config UCSI_ITEPD
> -	tristate "UCSI Interface Driver for ITE IT8851/IT8853"
> +	tristate "UCSI Interface Driver for ITE IT885x and IT527x series"
>  	depends on I2C
> +	depends on DRM || !DRM
> +	select DRM_AUX_HPD_BRIDGE if DRM_BRIDGE && OF
>  	help
>  	  This driver enables UCSI support on platforms that expose an
> -	  ITE IT8851/IT8853 Type-C Power Delivery controller over an I2C interface.
> +	  ITE IT885x or IT527x series Type-C Power Delivery controller
> +	  over an I2C interface. It also supports DisplayPort alternate
> +	  mode, including HPD notification through the DRM bridge.

Please split this part into separate patch.

Thanks,

--
heikki