The Huawei Matebook E Go tablet implements the UCSI interface in the
onboard EC. Add the glue driver to interface with the platform's UCSI
implementation.

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
---
 drivers/usb/typec/ucsi/Kconfig              |  10 +
 drivers/usb/typec/ucsi/Makefile             |   1 +
 drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c | 524 ++++++++++++++++++++
 3 files changed, 535 insertions(+)
 create mode 100644 drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index 680e1b87b..8a73df84a 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -78,4 +78,14 @@ config UCSI_LENOVO_YOGA_C630
 	  To compile the driver as a module, choose M here: the module will be
 	  called ucsi_yoga_c630.
 
+config UCSI_HUAWEI_GAOKUN
+	tristate "UCSI Interface Driver for Huawei Matebook E Go"
+	depends on EC_HUAWEI_GAOKUN
+	help
+	  This driver enables UCSI support on the Huawei Matebook E Go tablet,
+	  which is a sc8280xp-based 2-in-1 tablet.
+
+	  To compile the driver as a module, choose M here: the module will be
+	  called ucsi_huawei_gaokun.
+
 endif
diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
index aed41d238..0b400122b 100644
--- a/drivers/usb/typec/ucsi/Makefile
+++ b/drivers/usb/typec/ucsi/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_UCSI_CCG)			+= ucsi_ccg.o
 obj-$(CONFIG_UCSI_STM32G0)		+= ucsi_stm32g0.o
 obj-$(CONFIG_UCSI_PMIC_GLINK)		+= ucsi_glink.o
 obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)	+= ucsi_yoga_c630.o
+obj-$(CONFIG_UCSI_HUAWEI_GAOKUN)	+= ucsi_huawei_gaokun.o
diff --git a/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
new file mode 100644
index 000000000..044545b44
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
@@ -0,0 +1,524 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ucsi-huawei-gaokun - A UCSI driver for HUAWEI Matebook E Go
+ *
+ * reference: drivers/usb/typec/ucsi/ucsi_yoga_c630.c
+ *            drivers/usb/typec/ucsi/ucsi_glink.c
+ *            drivers/soc/qcom/pmic_glink_altmode.c
+ *
+ * Copyright (C) 2024 Pengyu Luo <mitltlatltl@gmail.com>
+ */
+
+#include <drm/bridge/aux-bridge.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/container_of.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_data/huawei-gaokun-ec.h>
+#include <linux/string.h>
+#include <linux/usb/pd_vdo.h>
+#include <linux/usb/typec_altmode.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/workqueue_types.h>
+
+#include "ucsi.h"
+
+#define EC_EVENT_UCSI	0x21
+#define EC_EVENT_USB	0x22
+
+#define GAOKUN_CCX_MASK		GENMASK(1, 0)
+#define GAOKUN_MUX_MASK		GENMASK(3, 2)
+
+#define GAOKUN_DPAM_MASK	GENMASK(3, 0)
+#define GAOKUN_HPD_STATE_MASK	BIT(4)
+#define GAOKUN_HPD_IRQ_MASK	BIT(5)
+
+#define GET_IDX(updt) (ffs(updt) - 1)
+
+#define CCX_TO_ORI(ccx) (++ccx % 3) /* convert ccx to enum typec_orientation */
+
+/* Configuration Channel Extension */
+enum gaokun_ucsi_ccx {
+	USBC_CCX_NORMAL,
+	USBC_CCX_REVERSE,
+	USBC_CCX_NONE,
+};
+
+enum gaokun_ucsi_mux {
+	USBC_MUX_NONE,
+	USBC_MUX_USB_2L,
+	USBC_MUX_DP_4L,
+	USBC_MUX_USB_DP,
+};
+/* based on pmic_glink_altmode_pin_assignment */
+enum gaokun_ucsi_dpam_pan {	/* DP Alt Mode Pin Assignments */
+	USBC_DPAM_PAN_NONE,
+	USBC_DPAM_PAN_A,	/* Not supported after USB Type-C Standard v1.0b */
+	USBC_DPAM_PAN_B,	/* Not supported after USB Type-C Standard v1.0b */
+	USBC_DPAM_PAN_C,	/* USBC_DPAM_PAN_C_REVERSE - 6 */
+	USBC_DPAM_PAN_D,
+	USBC_DPAM_PAN_E,
+	USBC_DPAM_PAN_F,	/* Not supported after USB Type-C Standard v1.0b */
+	USBC_DPAM_PAN_A_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
+	USBC_DPAM_PAN_B_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
+	USBC_DPAM_PAN_C_REVERSE,
+	USBC_DPAM_PAN_D_REVERSE,
+	USBC_DPAM_PAN_E_REVERSE,
+	USBC_DPAM_PAN_F_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
+};
+
+struct gaokun_ucsi_reg {
+	u8 port_num;
+	u8 port_updt;
+	u8 port_data[4];
+	u8 checksum;
+	u8 reserved;
+} __packed;
+
+struct gaokun_ucsi_port {
+	struct completion usb_ack;
+	spinlock_t lock;
+
+	struct gaokun_ucsi *ucsi;
+	struct auxiliary_device *bridge;
+
+	int idx;
+	enum gaokun_ucsi_ccx ccx;
+	enum gaokun_ucsi_mux mux;
+	u8 mode;
+	u16 svid;
+	u8 hpd_state;
+	u8 hpd_irq;
+};
+
+struct gaokun_ucsi {
+	struct gaokun_ec *ec;
+	struct ucsi *ucsi;
+	struct gaokun_ucsi_port *ports;
+	struct device *dev;
+	struct delayed_work work;
+	struct notifier_block nb;
+	u16 version;
+	u8 port_num;
+};
+
+/* -------------------------------------------------------------------------- */
+/* For UCSI */
+
+static int gaokun_ucsi_read_version(struct ucsi *ucsi, u16 *version)
+{
+	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
+
+	*version = uec->version;
+
+	return 0;
+}
+
+static int gaokun_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
+{
+	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
+	u8 buf[GAOKUN_UCSI_READ_SIZE];
+	int ret;
+
+	ret = gaokun_ec_ucsi_read(uec->ec, buf);
+	if (ret)
+		return ret;
+
+	memcpy(cci, buf, sizeof(*cci));
+
+	return 0;
+}
+
+static int gaokun_ucsi_read_message_in(struct ucsi *ucsi,
+				       void *val, size_t val_len)
+{
+	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
+	u8 buf[GAOKUN_UCSI_READ_SIZE];
+	int ret;
+
+	ret = gaokun_ec_ucsi_read(uec->ec, buf);
+	if (ret)
+		return ret;
+
+	memcpy(val, buf + GAOKUN_UCSI_CCI_SIZE,
+	       min(val_len, GAOKUN_UCSI_DATA_SIZE));
+
+	return 0;
+}
+
+static int gaokun_ucsi_async_control(struct ucsi *ucsi, u64 command)
+{
+	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
+	u8 buf[GAOKUN_UCSI_WRITE_SIZE] = {};
+
+	memcpy(buf, &command, sizeof(command));
+
+	return gaokun_ec_ucsi_write(uec->ec, buf);
+}
+
+static void gaokun_ucsi_update_connector(struct ucsi_connector *con)
+{
+	struct gaokun_ucsi *uec = ucsi_get_drvdata(con->ucsi);
+
+	if (con->num > uec->port_num)
+		return;
+
+	con->typec_cap.orientation_aware = true;
+}
+
+static void gaokun_set_orientation(struct ucsi_connector *con,
+				   struct gaokun_ucsi_port *port)
+{
+	enum gaokun_ucsi_ccx ccx;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	ccx = port->ccx;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	typec_set_orientation(con->port, CCX_TO_ORI(ccx));
+}
+
+static void gaokun_ucsi_connector_status(struct ucsi_connector *con)
+{
+	struct gaokun_ucsi *uec = ucsi_get_drvdata(con->ucsi);
+	int idx;
+
+	idx = con->num - 1;
+	if (con->num > uec->port_num) {
+		dev_warn(uec->dev, "set orientation out of range: con%d\n", idx);
+		return;
+	}
+
+	gaokun_set_orientation(con, &uec->ports[idx]);
+}
+
+const struct ucsi_operations gaokun_ucsi_ops = {
+	.read_version = gaokun_ucsi_read_version,
+	.read_cci = gaokun_ucsi_read_cci,
+	.read_message_in = gaokun_ucsi_read_message_in,
+	.sync_control = ucsi_sync_control_common,
+	.async_control = gaokun_ucsi_async_control,
+	.update_connector = gaokun_ucsi_update_connector,
+	.connector_status = gaokun_ucsi_connector_status,
+};
+
+/* -------------------------------------------------------------------------- */
+/* For Altmode */
+
+static void gaokun_ucsi_port_update(struct gaokun_ucsi_port *port,
+				    const u8 *port_data)
+{
+	struct gaokun_ucsi *uec = port->ucsi;
+	int offset = port->idx * 2; /* every port has 2 Bytes data */
+	unsigned long flags;
+	u8 dcc, ddi;
+
+	dcc = port_data[offset];
+	ddi = port_data[offset + 1];
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	port->ccx = FIELD_GET(GAOKUN_CCX_MASK, dcc);
+	port->mux = FIELD_GET(GAOKUN_MUX_MASK, dcc);
+	port->mode = FIELD_GET(GAOKUN_DPAM_MASK, ddi);
+	port->hpd_state = FIELD_GET(GAOKUN_HPD_STATE_MASK, ddi);
+	port->hpd_irq = FIELD_GET(GAOKUN_HPD_IRQ_MASK, ddi);
+
+	/* Mode and SVID are unused; keeping them to make things clearer */
+	switch (port->mode) {
+	case USBC_DPAM_PAN_C:
+	case USBC_DPAM_PAN_C_REVERSE:
+		port->mode = DP_PIN_ASSIGN_C; /* correct it for usb later */
+		break;
+	case USBC_DPAM_PAN_D:
+	case USBC_DPAM_PAN_D_REVERSE:
+		port->mode = DP_PIN_ASSIGN_D;
+		break;
+	case USBC_DPAM_PAN_E:
+	case USBC_DPAM_PAN_E_REVERSE:
+		port->mode = DP_PIN_ASSIGN_E;
+		break;
+	case USBC_DPAM_PAN_NONE:
+		port->mode = TYPEC_STATE_SAFE;
+		break;
+	default:
+		dev_warn(uec->dev, "unknow mode %d\n", port->mode);
+		break;
+	}
+
+	switch (port->mux) {
+	case USBC_MUX_NONE:
+		port->svid = 0;
+		break;
+	case USBC_MUX_USB_2L:
+		port->svid = USB_SID_PD;
+		port->mode = TYPEC_STATE_USB; /* same as PAN_C, correct it */
+		break;
+	case USBC_MUX_DP_4L:
+	case USBC_MUX_USB_DP:
+		port->svid = USB_SID_DISPLAYPORT;
+		break;
+	default:
+		dev_warn(uec->dev, "unknow mux state %d\n", port->mux);
+		break;
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int gaokun_ucsi_refresh(struct gaokun_ucsi *uec)
+{
+	struct gaokun_ucsi_reg ureg;
+	int ret, idx;
+
+	ret = gaokun_ec_ucsi_get_reg(uec->ec, (u8 *)&ureg);
+	if (ret)
+		return GAOKUN_UCSI_NO_PORT_UPDATE;
+
+	uec->port_num = ureg.port_num;
+	idx = GET_IDX(ureg.port_updt);
+
+	if (idx < 0 || idx >= ureg.port_num)
+		return GAOKUN_UCSI_NO_PORT_UPDATE;
+
+	gaokun_ucsi_port_update(&uec->ports[idx], ureg.port_data);
+	return idx;
+}
+
+static void gaokun_ucsi_handle_altmode(struct gaokun_ucsi_port *port)
+{
+	struct gaokun_ucsi *uec = port->ucsi;
+	int idx = port->idx;
+
+	if (idx >= uec->ucsi->cap.num_connectors) {
+		dev_warn(uec->dev, "altmode port out of range: %d\n", idx);
+		return;
+	}
+
+	/* UCSI callback .connector_status() have set orientation */
+	if (port->bridge)
+		drm_aux_hpd_bridge_notify(&port->bridge->dev,
+					  port->hpd_state ?
+					  connector_status_connected :
+					  connector_status_disconnected);
+
+	gaokun_ec_ucsi_pan_ack(uec->ec, port->idx);
+}
+
+static void gaokun_ucsi_altmode_notify_ind(struct gaokun_ucsi *uec)
+{
+	int idx;
+
+	 if (!uec->ucsi->connector) { /* slow to register */
+		 dev_err(uec->dev, "ucsi connector is not initialized yet\n");
+		 return;
+	 }
+
+	idx = gaokun_ucsi_refresh(uec);
+	if (idx == GAOKUN_UCSI_NO_PORT_UPDATE)
+		gaokun_ec_ucsi_pan_ack(uec->ec, idx); /* ack directly if no update */
+	else
+		gaokun_ucsi_handle_altmode(&uec->ports[idx]);
+}
+
+/*
+ * USB event is necessary for enabling altmode, the event should follow
+ * UCSI event, if not after timeout(this notify may be disabled somehow),
+ * then force to enable altmode.
+ */
+static void gaokun_ucsi_handle_no_usb_event(struct gaokun_ucsi *uec, int idx)
+{
+	struct gaokun_ucsi_port *port;
+
+	port = &uec->ports[idx];
+	if (!wait_for_completion_timeout(&port->usb_ack, 2 * HZ)) {
+		dev_warn(uec->dev, "No USB EVENT, triggered by UCSI EVENT");
+		gaokun_ucsi_altmode_notify_ind(uec);
+	}
+}
+
+static int gaokun_ucsi_notify(struct notifier_block *nb,
+			      unsigned long action, void *data)
+{
+	u32 cci;
+	struct gaokun_ucsi *uec = container_of(nb, struct gaokun_ucsi, nb);
+
+	switch (action) {
+	case EC_EVENT_USB:
+		gaokun_ucsi_altmode_notify_ind(uec);
+		return NOTIFY_OK;
+
+	case EC_EVENT_UCSI:
+		uec->ucsi->ops->read_cci(uec->ucsi, &cci);
+		ucsi_notify_common(uec->ucsi, cci);
+		if (UCSI_CCI_CONNECTOR(cci))
+			gaokun_ucsi_handle_no_usb_event(uec, UCSI_CCI_CONNECTOR(cci) - 1);
+
+		return NOTIFY_OK;
+
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+static inline int gaokun_ucsi_get_port_num(struct gaokun_ucsi *uec)
+{
+	struct gaokun_ucsi_reg ureg;
+	int ret;
+
+	ret = gaokun_ec_ucsi_get_reg(uec->ec, (u8 *)&ureg);
+
+	return ret ? 0 : ureg.port_num;
+}
+
+static int gaokun_ucsi_ports_init(struct gaokun_ucsi *uec)
+{
+	u32 port;
+	int i, ret, port_num;
+	struct device *dev = uec->dev;
+	struct gaokun_ucsi_port *ucsi_port;
+	struct fwnode_handle *fwnode;
+
+	port_num = gaokun_ucsi_get_port_num(uec);
+	uec->port_num = port_num;
+
+	uec->ports = devm_kcalloc(dev, port_num, sizeof(*(uec->ports)),
+				  GFP_KERNEL);
+	if (!uec->ports)
+		return -ENOMEM;
+
+	for (i = 0; i < port_num; ++i) {
+		ucsi_port = &uec->ports[i];
+		ucsi_port->ccx = USBC_CCX_NONE;
+		ucsi_port->idx = i;
+		ucsi_port->ucsi = uec;
+		init_completion(&ucsi_port->usb_ack);
+		spin_lock_init(&ucsi_port->lock);
+	}
+
+	device_for_each_child_node(dev, fwnode) {
+		ret = fwnode_property_read_u32(fwnode, "reg", &port);
+		if (ret < 0) {
+			dev_err(dev, "missing reg property of %pOFn\n", fwnode);
+			fwnode_handle_put(fwnode);
+			return ret;
+		}
+
+		if (port >= port_num) {
+			dev_warn(dev, "invalid connector number %d, ignoring\n", port);
+			continue;
+		}
+
+		ucsi_port = &uec->ports[port];
+		ucsi_port->bridge = devm_drm_dp_hpd_bridge_alloc(dev, to_of_node(fwnode));
+		if (IS_ERR(ucsi_port->bridge)) {
+			fwnode_handle_put(fwnode);
+			return PTR_ERR(ucsi_port->bridge);
+		}
+	}
+
+	for (i = 0; i < port_num; i++) {
+		if (!uec->ports[i].bridge)
+			continue;
+
+		ret = devm_drm_dp_hpd_bridge_add(dev, uec->ports[i].bridge);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void gaokun_ucsi_register_worker(struct work_struct *work)
+{
+	struct gaokun_ucsi *uec;
+	struct ucsi *ucsi;
+	int ret;
+
+	uec = container_of(work, struct gaokun_ucsi, work.work);
+	ucsi = uec->ucsi;
+	/* This may be a problem specific to sc8280xp-based machines */
+	ucsi->quirks = UCSI_NO_PARTNER_PDOS | UCSI_DELAY_DEVICE_PDOS;
+
+	ret = gaokun_ec_register_notify(uec->ec, &uec->nb);
+	if (ret) {
+		dev_err_probe(ucsi->dev, ret, "notifier register failed\n");
+		return;
+	}
+
+	ret = ucsi_register(ucsi);
+	if (ret)
+		dev_err_probe(ucsi->dev, ret, "ucsi register failed\n");
+}
+
+static inline int gaokun_ucsi_register(struct gaokun_ucsi *uec)
+{
+	/* EC can't handle UCSI properly in the early stage */
+	schedule_delayed_work(&uec->work, 3 * HZ);
+
+	return 0;
+}
+
+static int gaokun_ucsi_probe(struct auxiliary_device *adev,
+			     const struct auxiliary_device_id *id)
+{
+	struct gaokun_ec *ec = adev->dev.platform_data;
+	struct device *dev = &adev->dev;
+	struct gaokun_ucsi *uec;
+	int ret;
+
+	uec = devm_kzalloc(dev, sizeof(*uec), GFP_KERNEL);
+	if (!uec)
+		return -ENOMEM;
+
+	uec->ec = ec;
+	uec->dev = dev;
+	uec->version = 0x0100;
+	uec->nb.notifier_call = gaokun_ucsi_notify;
+
+	INIT_DELAYED_WORK(&uec->work, gaokun_ucsi_register_worker);
+
+	ret = gaokun_ucsi_ports_init(uec);
+	if (ret)
+		return ret;
+
+	uec->ucsi = ucsi_create(dev, &gaokun_ucsi_ops);
+	if (IS_ERR(uec->ucsi))
+		return PTR_ERR(uec->ucsi);
+
+	ucsi_set_drvdata(uec->ucsi, uec);
+	auxiliary_set_drvdata(adev, uec);
+
+	return gaokun_ucsi_register(uec);
+}
+
+static void gaokun_ucsi_remove(struct auxiliary_device *adev)
+{
+	struct gaokun_ucsi *uec = auxiliary_get_drvdata(adev);
+
+	gaokun_ec_unregister_notify(uec->ec, &uec->nb);
+	ucsi_unregister(uec->ucsi);
+	ucsi_destroy(uec->ucsi);
+}
+
+static const struct auxiliary_device_id gaokun_ucsi_id_table[] = {
+	{ .name = GAOKUN_MOD_NAME "." GAOKUN_DEV_UCSI, },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, gaokun_ucsi_id_table);
+
+static struct auxiliary_driver gaokun_ucsi_driver = {
+	.name = GAOKUN_DEV_UCSI,
+	.id_table = gaokun_ucsi_id_table,
+	.probe = gaokun_ucsi_probe,
+	.remove = gaokun_ucsi_remove,
+};
+
+module_auxiliary_driver(gaokun_ucsi_driver);
+
+MODULE_DESCRIPTION("HUAWEI Matebook E Go UCSI driver");
+MODULE_LICENSE("GPL");
-- 
2.47.1

Hi,

On Mon, Jan 06, 2025 at 01:41:57AM +0800, Pengyu Luo wrote:
> The Huawei Matebook E Go tablet implements the UCSI interface in the
> onboard EC. Add the glue driver to interface with the platform's UCSI
> implementation.
> 
> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> ---
>  drivers/usb/typec/ucsi/Kconfig              |  10 +
>  drivers/usb/typec/ucsi/Makefile             |   1 +
>  drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c | 524 ++++++++++++++++++++
>  3 files changed, 535 insertions(+)
>  create mode 100644 drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c

This did not apply cleanly anymore, but I guess you'll be rebasing in
any case. A few nitpicks below.

> diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> index 680e1b87b..8a73df84a 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -78,4 +78,14 @@ config UCSI_LENOVO_YOGA_C630
>  	  To compile the driver as a module, choose M here: the module will be
>  	  called ucsi_yoga_c630.
>  
> +config UCSI_HUAWEI_GAOKUN
> +	tristate "UCSI Interface Driver for Huawei Matebook E Go"
> +	depends on EC_HUAWEI_GAOKUN
> +	help
> +	  This driver enables UCSI support on the Huawei Matebook E Go tablet,
> +	  which is a sc8280xp-based 2-in-1 tablet.
> +
> +	  To compile the driver as a module, choose M here: the module will be
> +	  called ucsi_huawei_gaokun.
> +
>  endif
> diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> index aed41d238..0b400122b 100644
> --- a/drivers/usb/typec/ucsi/Makefile
> +++ b/drivers/usb/typec/ucsi/Makefile
> @@ -22,3 +22,4 @@ obj-$(CONFIG_UCSI_CCG)			+= ucsi_ccg.o
>  obj-$(CONFIG_UCSI_STM32G0)		+= ucsi_stm32g0.o
>  obj-$(CONFIG_UCSI_PMIC_GLINK)		+= ucsi_glink.o
>  obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)	+= ucsi_yoga_c630.o
> +obj-$(CONFIG_UCSI_HUAWEI_GAOKUN)	+= ucsi_huawei_gaokun.o
> diff --git a/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
> new file mode 100644
> index 000000000..044545b44
> --- /dev/null
> +++ b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
> @@ -0,0 +1,524 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ucsi-huawei-gaokun - A UCSI driver for HUAWEI Matebook E Go
> + *
> + * reference: drivers/usb/typec/ucsi/ucsi_yoga_c630.c
> + *            drivers/usb/typec/ucsi/ucsi_glink.c
> + *            drivers/soc/qcom/pmic_glink_altmode.c
> + *
> + * Copyright (C) 2024 Pengyu Luo <mitltlatltl@gmail.com>
> + */
> +
> +#include <drm/bridge/aux-bridge.h>
> +#include <linux/auxiliary_bus.h>
> +#include <linux/bitops.h>
> +#include <linux/completion.h>
> +#include <linux/container_of.h>
> +#include <linux/module.h>
> +#include <linux/notifier.h>
> +#include <linux/of.h>
> +#include <linux/platform_data/huawei-gaokun-ec.h>
> +#include <linux/string.h>
> +#include <linux/usb/pd_vdo.h>
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/workqueue_types.h>
> +
> +#include "ucsi.h"
> +
> +#define EC_EVENT_UCSI	0x21
> +#define EC_EVENT_USB	0x22
> +
> +#define GAOKUN_CCX_MASK		GENMASK(1, 0)
> +#define GAOKUN_MUX_MASK		GENMASK(3, 2)
> +
> +#define GAOKUN_DPAM_MASK	GENMASK(3, 0)
> +#define GAOKUN_HPD_STATE_MASK	BIT(4)
> +#define GAOKUN_HPD_IRQ_MASK	BIT(5)
> +
> +#define GET_IDX(updt) (ffs(updt) - 1)
> +
> +#define CCX_TO_ORI(ccx) (++ccx % 3) /* convert ccx to enum typec_orientation */
> +
> +/* Configuration Channel Extension */
> +enum gaokun_ucsi_ccx {
> +	USBC_CCX_NORMAL,
> +	USBC_CCX_REVERSE,
> +	USBC_CCX_NONE,
> +};
> +
> +enum gaokun_ucsi_mux {
> +	USBC_MUX_NONE,
> +	USBC_MUX_USB_2L,
> +	USBC_MUX_DP_4L,
> +	USBC_MUX_USB_DP,
> +};
> +/* based on pmic_glink_altmode_pin_assignment */
> +enum gaokun_ucsi_dpam_pan {	/* DP Alt Mode Pin Assignments */
> +	USBC_DPAM_PAN_NONE,
> +	USBC_DPAM_PAN_A,	/* Not supported after USB Type-C Standard v1.0b */
> +	USBC_DPAM_PAN_B,	/* Not supported after USB Type-C Standard v1.0b */
> +	USBC_DPAM_PAN_C,	/* USBC_DPAM_PAN_C_REVERSE - 6 */
> +	USBC_DPAM_PAN_D,
> +	USBC_DPAM_PAN_E,
> +	USBC_DPAM_PAN_F,	/* Not supported after USB Type-C Standard v1.0b */
> +	USBC_DPAM_PAN_A_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
> +	USBC_DPAM_PAN_B_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
> +	USBC_DPAM_PAN_C_REVERSE,
> +	USBC_DPAM_PAN_D_REVERSE,
> +	USBC_DPAM_PAN_E_REVERSE,
> +	USBC_DPAM_PAN_F_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
> +};
> +
> +struct gaokun_ucsi_reg {
> +	u8 port_num;
> +	u8 port_updt;
> +	u8 port_data[4];
> +	u8 checksum;
> +	u8 reserved;
> +} __packed;
> +
> +struct gaokun_ucsi_port {
> +	struct completion usb_ack;
> +	spinlock_t lock;
> +
> +	struct gaokun_ucsi *ucsi;
> +	struct auxiliary_device *bridge;
> +
> +	int idx;
> +	enum gaokun_ucsi_ccx ccx;
> +	enum gaokun_ucsi_mux mux;
> +	u8 mode;
> +	u16 svid;
> +	u8 hpd_state;
> +	u8 hpd_irq;
> +};
> +
> +struct gaokun_ucsi {
> +	struct gaokun_ec *ec;
> +	struct ucsi *ucsi;
> +	struct gaokun_ucsi_port *ports;
> +	struct device *dev;
> +	struct delayed_work work;
> +	struct notifier_block nb;
> +	u16 version;
> +	u8 port_num;
> +};
> +
> +/* -------------------------------------------------------------------------- */
> +/* For UCSI */
> +
> +static int gaokun_ucsi_read_version(struct ucsi *ucsi, u16 *version)
> +{
> +	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> +
> +	*version = uec->version;
> +
> +	return 0;
> +}
> +
> +static int gaokun_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
> +{
> +	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> +	u8 buf[GAOKUN_UCSI_READ_SIZE];
> +	int ret;
> +
> +	ret = gaokun_ec_ucsi_read(uec->ec, buf);
> +	if (ret)
> +		return ret;
> +
> +	memcpy(cci, buf, sizeof(*cci));
> +
> +	return 0;
> +}
> +
> +static int gaokun_ucsi_read_message_in(struct ucsi *ucsi,
> +				       void *val, size_t val_len)
> +{
> +	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> +	u8 buf[GAOKUN_UCSI_READ_SIZE];
> +	int ret;
> +
> +	ret = gaokun_ec_ucsi_read(uec->ec, buf);
> +	if (ret)
> +		return ret;
> +
> +	memcpy(val, buf + GAOKUN_UCSI_CCI_SIZE,
> +	       min(val_len, GAOKUN_UCSI_DATA_SIZE));
> +
> +	return 0;
> +}
> +
> +static int gaokun_ucsi_async_control(struct ucsi *ucsi, u64 command)
> +{
> +	struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> +	u8 buf[GAOKUN_UCSI_WRITE_SIZE] = {};
> +
> +	memcpy(buf, &command, sizeof(command));
> +
> +	return gaokun_ec_ucsi_write(uec->ec, buf);
> +}
> +
> +static void gaokun_ucsi_update_connector(struct ucsi_connector *con)
> +{
> +	struct gaokun_ucsi *uec = ucsi_get_drvdata(con->ucsi);
> +
> +	if (con->num > uec->port_num)
> +		return;
> +
> +	con->typec_cap.orientation_aware = true;
> +}
> +
> +static void gaokun_set_orientation(struct ucsi_connector *con,
> +				   struct gaokun_ucsi_port *port)
> +{
> +	enum gaokun_ucsi_ccx ccx;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&port->lock, flags);
> +	ccx = port->ccx;
> +	spin_unlock_irqrestore(&port->lock, flags);
> +
> +	typec_set_orientation(con->port, CCX_TO_ORI(ccx));
> +}
> +
> +static void gaokun_ucsi_connector_status(struct ucsi_connector *con)
> +{
> +	struct gaokun_ucsi *uec = ucsi_get_drvdata(con->ucsi);
> +	int idx;
> +
> +	idx = con->num - 1;
> +	if (con->num > uec->port_num) {
> +		dev_warn(uec->dev, "set orientation out of range: con%d\n", idx);
> +		return;
> +	}
> +
> +	gaokun_set_orientation(con, &uec->ports[idx]);
> +}
> +
> +const struct ucsi_operations gaokun_ucsi_ops = {
> +	.read_version = gaokun_ucsi_read_version,
> +	.read_cci = gaokun_ucsi_read_cci,
> +	.read_message_in = gaokun_ucsi_read_message_in,
> +	.sync_control = ucsi_sync_control_common,
> +	.async_control = gaokun_ucsi_async_control,
> +	.update_connector = gaokun_ucsi_update_connector,
> +	.connector_status = gaokun_ucsi_connector_status,
> +};
> +
> +/* -------------------------------------------------------------------------- */
> +/* For Altmode */
> +
> +static void gaokun_ucsi_port_update(struct gaokun_ucsi_port *port,
> +				    const u8 *port_data)
> +{
> +	struct gaokun_ucsi *uec = port->ucsi;
> +	int offset = port->idx * 2; /* every port has 2 Bytes data */
> +	unsigned long flags;
> +	u8 dcc, ddi;
> +
> +	dcc = port_data[offset];
> +	ddi = port_data[offset + 1];
> +
> +	spin_lock_irqsave(&port->lock, flags);
> +
> +	port->ccx = FIELD_GET(GAOKUN_CCX_MASK, dcc);
> +	port->mux = FIELD_GET(GAOKUN_MUX_MASK, dcc);
> +	port->mode = FIELD_GET(GAOKUN_DPAM_MASK, ddi);
> +	port->hpd_state = FIELD_GET(GAOKUN_HPD_STATE_MASK, ddi);
> +	port->hpd_irq = FIELD_GET(GAOKUN_HPD_IRQ_MASK, ddi);
> +
> +	/* Mode and SVID are unused; keeping them to make things clearer */
> +	switch (port->mode) {
> +	case USBC_DPAM_PAN_C:
> +	case USBC_DPAM_PAN_C_REVERSE:
> +		port->mode = DP_PIN_ASSIGN_C; /* correct it for usb later */
> +		break;
> +	case USBC_DPAM_PAN_D:
> +	case USBC_DPAM_PAN_D_REVERSE:
> +		port->mode = DP_PIN_ASSIGN_D;
> +		break;
> +	case USBC_DPAM_PAN_E:
> +	case USBC_DPAM_PAN_E_REVERSE:
> +		port->mode = DP_PIN_ASSIGN_E;
> +		break;
> +	case USBC_DPAM_PAN_NONE:
> +		port->mode = TYPEC_STATE_SAFE;
> +		break;
> +	default:
> +		dev_warn(uec->dev, "unknow mode %d\n", port->mode);
> +		break;
> +	}
> +
> +	switch (port->mux) {
> +	case USBC_MUX_NONE:
> +		port->svid = 0;
> +		break;
> +	case USBC_MUX_USB_2L:
> +		port->svid = USB_SID_PD;
> +		port->mode = TYPEC_STATE_USB; /* same as PAN_C, correct it */
> +		break;
> +	case USBC_MUX_DP_4L:
> +	case USBC_MUX_USB_DP:
> +		port->svid = USB_SID_DISPLAYPORT;
> +		break;
> +	default:
> +		dev_warn(uec->dev, "unknow mux state %d\n", port->mux);
> +		break;
> +	}
> +
> +	spin_unlock_irqrestore(&port->lock, flags);
> +}
> +
> +static int gaokun_ucsi_refresh(struct gaokun_ucsi *uec)
> +{
> +	struct gaokun_ucsi_reg ureg;
> +	int ret, idx;
> +
> +	ret = gaokun_ec_ucsi_get_reg(uec->ec, (u8 *)&ureg);
> +	if (ret)
> +		return GAOKUN_UCSI_NO_PORT_UPDATE;
> +
> +	uec->port_num = ureg.port_num;
> +	idx = GET_IDX(ureg.port_updt);
> +
> +	if (idx < 0 || idx >= ureg.port_num)
> +		return GAOKUN_UCSI_NO_PORT_UPDATE;
> +
> +	gaokun_ucsi_port_update(&uec->ports[idx], ureg.port_data);
> +	return idx;
> +}
> +
> +static void gaokun_ucsi_handle_altmode(struct gaokun_ucsi_port *port)
> +{
> +	struct gaokun_ucsi *uec = port->ucsi;
> +	int idx = port->idx;
> +
> +	if (idx >= uec->ucsi->cap.num_connectors) {
> +		dev_warn(uec->dev, "altmode port out of range: %d\n", idx);
> +		return;
> +	}
> +
> +	/* UCSI callback .connector_status() have set orientation */
> +	if (port->bridge)
> +		drm_aux_hpd_bridge_notify(&port->bridge->dev,
> +					  port->hpd_state ?
> +					  connector_status_connected :
> +					  connector_status_disconnected);
> +
> +	gaokun_ec_ucsi_pan_ack(uec->ec, port->idx);
> +}
> +
> +static void gaokun_ucsi_altmode_notify_ind(struct gaokun_ucsi *uec)
> +{
> +	int idx;
> +
> +	 if (!uec->ucsi->connector) { /* slow to register */
> +		 dev_err(uec->dev, "ucsi connector is not initialized yet\n");
> +		 return;
> +	 }
> +
> +	idx = gaokun_ucsi_refresh(uec);
> +	if (idx == GAOKUN_UCSI_NO_PORT_UPDATE)
> +		gaokun_ec_ucsi_pan_ack(uec->ec, idx); /* ack directly if no update */
> +	else
> +		gaokun_ucsi_handle_altmode(&uec->ports[idx]);
> +}
> +
> +/*
> + * USB event is necessary for enabling altmode, the event should follow
> + * UCSI event, if not after timeout(this notify may be disabled somehow),
> + * then force to enable altmode.
> + */
> +static void gaokun_ucsi_handle_no_usb_event(struct gaokun_ucsi *uec, int idx)
> +{
> +	struct gaokun_ucsi_port *port;
> +
> +	port = &uec->ports[idx];
> +	if (!wait_for_completion_timeout(&port->usb_ack, 2 * HZ)) {
> +		dev_warn(uec->dev, "No USB EVENT, triggered by UCSI EVENT");
> +		gaokun_ucsi_altmode_notify_ind(uec);
> +	}
> +}
> +
> +static int gaokun_ucsi_notify(struct notifier_block *nb,
> +			      unsigned long action, void *data)
> +{
> +	u32 cci;
> +	struct gaokun_ucsi *uec = container_of(nb, struct gaokun_ucsi, nb);
> +
> +	switch (action) {
> +	case EC_EVENT_USB:
> +		gaokun_ucsi_altmode_notify_ind(uec);
> +		return NOTIFY_OK;
> +
> +	case EC_EVENT_UCSI:
> +		uec->ucsi->ops->read_cci(uec->ucsi, &cci);

I think it would be more clear here to just call
gaokun_ucsi_read_cci() directly here.

> +		ucsi_notify_common(uec->ucsi, cci);
> +		if (UCSI_CCI_CONNECTOR(cci))
> +			gaokun_ucsi_handle_no_usb_event(uec, UCSI_CCI_CONNECTOR(cci) - 1);
> +
> +		return NOTIFY_OK;
> +
> +	default:
> +		return NOTIFY_DONE;
> +	}
> +}
> +
> +static inline int gaokun_ucsi_get_port_num(struct gaokun_ucsi *uec)
> +{
> +	struct gaokun_ucsi_reg ureg;
> +	int ret;
> +
> +	ret = gaokun_ec_ucsi_get_reg(uec->ec, (u8 *)&ureg);
> +
> +	return ret ? 0 : ureg.port_num;
> +}

This function does not look like it's necessary to me.

> +static int gaokun_ucsi_ports_init(struct gaokun_ucsi *uec)
> +{
> +	u32 port;
> +	int i, ret, port_num;
> +	struct device *dev = uec->dev;
> +	struct gaokun_ucsi_port *ucsi_port;
> +	struct fwnode_handle *fwnode;
> +
> +	port_num = gaokun_ucsi_get_port_num(uec);
> +	uec->port_num = port_num;

struct gaokun_ucsi_reg ureg = { };

gaokun_ec_ucsi_get_reg(uec->ec, &ureg);
port_num = ureg->port_num;

(Btw. port_num here is confusing IMO, because you are not talking
about the number of a port, but instead number of all ports. So
something like num_ports or nports would be better).

> +	uec->ports = devm_kcalloc(dev, port_num, sizeof(*(uec->ports)),
> +				  GFP_KERNEL);
> +	if (!uec->ports)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < port_num; ++i) {
> +		ucsi_port = &uec->ports[i];
> +		ucsi_port->ccx = USBC_CCX_NONE;
> +		ucsi_port->idx = i;
> +		ucsi_port->ucsi = uec;
> +		init_completion(&ucsi_port->usb_ack);
> +		spin_lock_init(&ucsi_port->lock);
> +	}
> +
> +	device_for_each_child_node(dev, fwnode) {
> +		ret = fwnode_property_read_u32(fwnode, "reg", &port);
> +		if (ret < 0) {
> +			dev_err(dev, "missing reg property of %pOFn\n", fwnode);
> +			fwnode_handle_put(fwnode);
> +			return ret;
> +		}
> +
> +		if (port >= port_num) {
> +			dev_warn(dev, "invalid connector number %d, ignoring\n", port);
> +			continue;
> +		}
> +
> +		ucsi_port = &uec->ports[port];
> +		ucsi_port->bridge = devm_drm_dp_hpd_bridge_alloc(dev, to_of_node(fwnode));
> +		if (IS_ERR(ucsi_port->bridge)) {
> +			fwnode_handle_put(fwnode);
> +			return PTR_ERR(ucsi_port->bridge);
> +		}
> +	}
> +
> +	for (i = 0; i < port_num; i++) {
> +		if (!uec->ports[i].bridge)
> +			continue;
> +
> +		ret = devm_drm_dp_hpd_bridge_add(dev, uec->ports[i].bridge);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void gaokun_ucsi_register_worker(struct work_struct *work)
> +{
> +	struct gaokun_ucsi *uec;
> +	struct ucsi *ucsi;
> +	int ret;
> +
> +	uec = container_of(work, struct gaokun_ucsi, work.work);
> +	ucsi = uec->ucsi;
> +	/* This may be a problem specific to sc8280xp-based machines */
> +	ucsi->quirks = UCSI_NO_PARTNER_PDOS | UCSI_DELAY_DEVICE_PDOS;
> +
> +	ret = gaokun_ec_register_notify(uec->ec, &uec->nb);
> +	if (ret) {
> +		dev_err_probe(ucsi->dev, ret, "notifier register failed\n");
> +		return;
> +	}
> +
> +	ret = ucsi_register(ucsi);
> +	if (ret)
> +		dev_err_probe(ucsi->dev, ret, "ucsi register failed\n");
> +}
> +
> +static inline int gaokun_ucsi_register(struct gaokun_ucsi *uec)
> +{
> +	/* EC can't handle UCSI properly in the early stage */
> +	schedule_delayed_work(&uec->work, 3 * HZ);
> +
> +	return 0;
> +}

This whole function is unnecessary.

> +static int gaokun_ucsi_probe(struct auxiliary_device *adev,
> +			     const struct auxiliary_device_id *id)
> +{
> +	struct gaokun_ec *ec = adev->dev.platform_data;
> +	struct device *dev = &adev->dev;
> +	struct gaokun_ucsi *uec;
> +	int ret;
> +
> +	uec = devm_kzalloc(dev, sizeof(*uec), GFP_KERNEL);
> +	if (!uec)
> +		return -ENOMEM;
> +
> +	uec->ec = ec;
> +	uec->dev = dev;
> +	uec->version = 0x0100;

Please add a definition for UCSI v1.0 to ucsi.h (separate patch).

> +	uec->nb.notifier_call = gaokun_ucsi_notify;
> +
> +	INIT_DELAYED_WORK(&uec->work, gaokun_ucsi_register_worker);
> +
> +	ret = gaokun_ucsi_ports_init(uec);
> +	if (ret)
> +		return ret;
> +
> +	uec->ucsi = ucsi_create(dev, &gaokun_ucsi_ops);
> +	if (IS_ERR(uec->ucsi))
> +		return PTR_ERR(uec->ucsi);
> +
> +	ucsi_set_drvdata(uec->ucsi, uec);
> +	auxiliary_set_drvdata(adev, uec);
> +
> +	return gaokun_ucsi_register(uec);
> +}
> +
> +static void gaokun_ucsi_remove(struct auxiliary_device *adev)
> +{
> +	struct gaokun_ucsi *uec = auxiliary_get_drvdata(adev);
> +
> +	gaokun_ec_unregister_notify(uec->ec, &uec->nb);
> +	ucsi_unregister(uec->ucsi);
> +	ucsi_destroy(uec->ucsi);
> +}
> +
> +static const struct auxiliary_device_id gaokun_ucsi_id_table[] = {
> +	{ .name = GAOKUN_MOD_NAME "." GAOKUN_DEV_UCSI, },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(auxiliary, gaokun_ucsi_id_table);
> +
> +static struct auxiliary_driver gaokun_ucsi_driver = {
> +	.name = GAOKUN_DEV_UCSI,
> +	.id_table = gaokun_ucsi_id_table,
> +	.probe = gaokun_ucsi_probe,
> +	.remove = gaokun_ucsi_remove,
> +};
> +
> +module_auxiliary_driver(gaokun_ucsi_driver);
> +
> +MODULE_DESCRIPTION("HUAWEI Matebook E Go UCSI driver");
> +MODULE_LICENSE("GPL");

thanks,

-- 
heikki

On Tue, Jan 7, 2025 at 8:30 PM Heikki Krogerus <heikki.krogerus@linux.intel.com> wrote:
>
> Hi,
>
> On Mon, Jan 06, 2025 at 01:41:57AM +0800, Pengyu Luo wrote:
> > The Huawei Matebook E Go tablet implements the UCSI interface in the
> > onboard EC. Add the glue driver to interface with the platform's UCSI
> > implementation.
> >
> > Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> > ---
> >  drivers/usb/typec/ucsi/Kconfig              |  10 +
> >  drivers/usb/typec/ucsi/Makefile             |   1 +
> >  drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c | 524 ++++++++++++++++++++
> >  3 files changed, 535 insertions(+)
> >  create mode 100644 drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
>
> This did not apply cleanly anymore, but I guess you'll be rebasing in
> any case. A few nitpicks below.
>

I see. I wrote them based on the mainline, then I formated them. I think
I should rebase to linux-next.

> > diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> > index 680e1b87b..8a73df84a 100644
> > --- a/drivers/usb/typec/ucsi/Kconfig
> > +++ b/drivers/usb/typec/ucsi/Kconfig
> > @@ -78,4 +78,14 @@ config UCSI_LENOVO_YOGA_C630
> >         To compile the driver as a module, choose M here: the module will be
> >         called ucsi_yoga_c630.
> >
> > +config UCSI_HUAWEI_GAOKUN
> > +     tristate "UCSI Interface Driver for Huawei Matebook E Go"
> > +     depends on EC_HUAWEI_GAOKUN
> > +     help
> > +       This driver enables UCSI support on the Huawei Matebook E Go tablet,
> > +       which is a sc8280xp-based 2-in-1 tablet.
> > +
> > +       To compile the driver as a module, choose M here: the module will be
> > +       called ucsi_huawei_gaokun.
> > +
> >  endif
> > diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> > index aed41d238..0b400122b 100644
> > --- a/drivers/usb/typec/ucsi/Makefile
> > +++ b/drivers/usb/typec/ucsi/Makefile
> > @@ -22,3 +22,4 @@ obj-$(CONFIG_UCSI_CCG)                      += ucsi_ccg.o
> >  obj-$(CONFIG_UCSI_STM32G0)           += ucsi_stm32g0.o
> >  obj-$(CONFIG_UCSI_PMIC_GLINK)                += ucsi_glink.o
> >  obj-$(CONFIG_UCSI_LENOVO_YOGA_C630)  += ucsi_yoga_c630.o
> > +obj-$(CONFIG_UCSI_HUAWEI_GAOKUN)     += ucsi_huawei_gaokun.o
> > diff --git a/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
> > new file mode 100644
> > index 000000000..044545b44
> > --- /dev/null
> > +++ b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
> > @@ -0,0 +1,524 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * ucsi-huawei-gaokun - A UCSI driver for HUAWEI Matebook E Go
> > + *
> > + * reference: drivers/usb/typec/ucsi/ucsi_yoga_c630.c
> > + *            drivers/usb/typec/ucsi/ucsi_glink.c
> > + *            drivers/soc/qcom/pmic_glink_altmode.c
> > + *
> > + * Copyright (C) 2024 Pengyu Luo <mitltlatltl@gmail.com>
> > + */
> > +
> > +#include <drm/bridge/aux-bridge.h>
> > +#include <linux/auxiliary_bus.h>
> > +#include <linux/bitops.h>
> > +#include <linux/completion.h>
> > +#include <linux/container_of.h>
> > +#include <linux/module.h>
> > +#include <linux/notifier.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_data/huawei-gaokun-ec.h>
> > +#include <linux/string.h>
> > +#include <linux/usb/pd_vdo.h>
> > +#include <linux/usb/typec_altmode.h>
> > +#include <linux/usb/typec_dp.h>
> > +#include <linux/workqueue_types.h>
> > +
> > +#include "ucsi.h"
> > +
> > +#define EC_EVENT_UCSI        0x21
> > +#define EC_EVENT_USB 0x22
> > +
> > +#define GAOKUN_CCX_MASK              GENMASK(1, 0)
> > +#define GAOKUN_MUX_MASK              GENMASK(3, 2)
> > +
> > +#define GAOKUN_DPAM_MASK     GENMASK(3, 0)
> > +#define GAOKUN_HPD_STATE_MASK        BIT(4)
> > +#define GAOKUN_HPD_IRQ_MASK  BIT(5)
> > +
> > +#define GET_IDX(updt) (ffs(updt) - 1)
> > +
> > +#define CCX_TO_ORI(ccx) (++ccx % 3) /* convert ccx to enum typec_orientation */
> > +
> > +/* Configuration Channel Extension */
> > +enum gaokun_ucsi_ccx {
> > +     USBC_CCX_NORMAL,
> > +     USBC_CCX_REVERSE,
> > +     USBC_CCX_NONE,
> > +};
> > +
> > +enum gaokun_ucsi_mux {
> > +     USBC_MUX_NONE,
> > +     USBC_MUX_USB_2L,
> > +     USBC_MUX_DP_4L,
> > +     USBC_MUX_USB_DP,
> > +};
> > +/* based on pmic_glink_altmode_pin_assignment */
> > +enum gaokun_ucsi_dpam_pan {  /* DP Alt Mode Pin Assignments */
> > +     USBC_DPAM_PAN_NONE,
> > +     USBC_DPAM_PAN_A,        /* Not supported after USB Type-C Standard v1.0b */
> > +     USBC_DPAM_PAN_B,        /* Not supported after USB Type-C Standard v1.0b */
> > +     USBC_DPAM_PAN_C,        /* USBC_DPAM_PAN_C_REVERSE - 6 */
> > +     USBC_DPAM_PAN_D,
> > +     USBC_DPAM_PAN_E,
> > +     USBC_DPAM_PAN_F,        /* Not supported after USB Type-C Standard v1.0b */
> > +     USBC_DPAM_PAN_A_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
> > +     USBC_DPAM_PAN_B_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
> > +     USBC_DPAM_PAN_C_REVERSE,
> > +     USBC_DPAM_PAN_D_REVERSE,
> > +     USBC_DPAM_PAN_E_REVERSE,
> > +     USBC_DPAM_PAN_F_REVERSE,/* Not supported after USB Type-C Standard v1.0b */
> > +};
> > +
> > +struct gaokun_ucsi_reg {
> > +     u8 port_num;
> > +     u8 port_updt;
> > +     u8 port_data[4];
> > +     u8 checksum;
> > +     u8 reserved;
> > +} __packed;
> > +
> > +struct gaokun_ucsi_port {
> > +     struct completion usb_ack;
> > +     spinlock_t lock;
> > +
> > +     struct gaokun_ucsi *ucsi;
> > +     struct auxiliary_device *bridge;
> > +
> > +     int idx;
> > +     enum gaokun_ucsi_ccx ccx;
> > +     enum gaokun_ucsi_mux mux;
> > +     u8 mode;
> > +     u16 svid;
> > +     u8 hpd_state;
> > +     u8 hpd_irq;
> > +};
> > +
> > +struct gaokun_ucsi {
> > +     struct gaokun_ec *ec;
> > +     struct ucsi *ucsi;
> > +     struct gaokun_ucsi_port *ports;
> > +     struct device *dev;
> > +     struct delayed_work work;
> > +     struct notifier_block nb;
> > +     u16 version;
> > +     u8 port_num;
> > +};
> > +
> > +/* -------------------------------------------------------------------------- */
> > +/* For UCSI */
> > +
> > +static int gaokun_ucsi_read_version(struct ucsi *ucsi, u16 *version)
> > +{
> > +     struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> > +
> > +     *version = uec->version;
> > +
> > +     return 0;
> > +}
> > +
> > +static int gaokun_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
> > +{
> > +     struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> > +     u8 buf[GAOKUN_UCSI_READ_SIZE];
> > +     int ret;
> > +
> > +     ret = gaokun_ec_ucsi_read(uec->ec, buf);
> > +     if (ret)
> > +             return ret;
> > +
> > +     memcpy(cci, buf, sizeof(*cci));
> > +
> > +     return 0;
> > +}
> > +
> > +static int gaokun_ucsi_read_message_in(struct ucsi *ucsi,
> > +                                    void *val, size_t val_len)
> > +{
> > +     struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> > +     u8 buf[GAOKUN_UCSI_READ_SIZE];
> > +     int ret;
> > +
> > +     ret = gaokun_ec_ucsi_read(uec->ec, buf);
> > +     if (ret)
> > +             return ret;
> > +
> > +     memcpy(val, buf + GAOKUN_UCSI_CCI_SIZE,
> > +            min(val_len, GAOKUN_UCSI_DATA_SIZE));
> > +
> > +     return 0;
> > +}
> > +
> > +static int gaokun_ucsi_async_control(struct ucsi *ucsi, u64 command)
> > +{
> > +     struct gaokun_ucsi *uec = ucsi_get_drvdata(ucsi);
> > +     u8 buf[GAOKUN_UCSI_WRITE_SIZE] = {};
> > +
> > +     memcpy(buf, &command, sizeof(command));
> > +
> > +     return gaokun_ec_ucsi_write(uec->ec, buf);
> > +}
> > +
> > +static void gaokun_ucsi_update_connector(struct ucsi_connector *con)
> > +{
> > +     struct gaokun_ucsi *uec = ucsi_get_drvdata(con->ucsi);
> > +
> > +     if (con->num > uec->port_num)
> > +             return;
> > +
> > +     con->typec_cap.orientation_aware = true;
> > +}
> > +
> > +static void gaokun_set_orientation(struct ucsi_connector *con,
> > +                                struct gaokun_ucsi_port *port)
> > +{
> > +     enum gaokun_ucsi_ccx ccx;
> > +     unsigned long flags;
> > +
> > +     spin_lock_irqsave(&port->lock, flags);
> > +     ccx = port->ccx;
> > +     spin_unlock_irqrestore(&port->lock, flags);
> > +
> > +     typec_set_orientation(con->port, CCX_TO_ORI(ccx));
> > +}
> > +
> > +static void gaokun_ucsi_connector_status(struct ucsi_connector *con)
> > +{
> > +     struct gaokun_ucsi *uec = ucsi_get_drvdata(con->ucsi);
> > +     int idx;
> > +
> > +     idx = con->num - 1;
> > +     if (con->num > uec->port_num) {
> > +             dev_warn(uec->dev, "set orientation out of range: con%d\n", idx);
> > +             return;
> > +     }
> > +
> > +     gaokun_set_orientation(con, &uec->ports[idx]);
> > +}
> > +
> > +const struct ucsi_operations gaokun_ucsi_ops = {
> > +     .read_version = gaokun_ucsi_read_version,
> > +     .read_cci = gaokun_ucsi_read_cci,
> > +     .read_message_in = gaokun_ucsi_read_message_in,
> > +     .sync_control = ucsi_sync_control_common,
> > +     .async_control = gaokun_ucsi_async_control,
> > +     .update_connector = gaokun_ucsi_update_connector,
> > +     .connector_status = gaokun_ucsi_connector_status,
> > +};
> > +
> > +/* -------------------------------------------------------------------------- */
> > +/* For Altmode */
> > +
> > +static void gaokun_ucsi_port_update(struct gaokun_ucsi_port *port,
> > +                                 const u8 *port_data)
> > +{
> > +     struct gaokun_ucsi *uec = port->ucsi;
> > +     int offset = port->idx * 2; /* every port has 2 Bytes data */
> > +     unsigned long flags;
> > +     u8 dcc, ddi;
> > +
> > +     dcc = port_data[offset];
> > +     ddi = port_data[offset + 1];
> > +
> > +     spin_lock_irqsave(&port->lock, flags);
> > +
> > +     port->ccx = FIELD_GET(GAOKUN_CCX_MASK, dcc);
> > +     port->mux = FIELD_GET(GAOKUN_MUX_MASK, dcc);
> > +     port->mode = FIELD_GET(GAOKUN_DPAM_MASK, ddi);
> > +     port->hpd_state = FIELD_GET(GAOKUN_HPD_STATE_MASK, ddi);
> > +     port->hpd_irq = FIELD_GET(GAOKUN_HPD_IRQ_MASK, ddi);
> > +
> > +     /* Mode and SVID are unused; keeping them to make things clearer */
> > +     switch (port->mode) {
> > +     case USBC_DPAM_PAN_C:
> > +     case USBC_DPAM_PAN_C_REVERSE:
> > +             port->mode = DP_PIN_ASSIGN_C; /* correct it for usb later */
> > +             break;
> > +     case USBC_DPAM_PAN_D:
> > +     case USBC_DPAM_PAN_D_REVERSE:
> > +             port->mode = DP_PIN_ASSIGN_D;
> > +             break;
> > +     case USBC_DPAM_PAN_E:
> > +     case USBC_DPAM_PAN_E_REVERSE:
> > +             port->mode = DP_PIN_ASSIGN_E;
> > +             break;
> > +     case USBC_DPAM_PAN_NONE:
> > +             port->mode = TYPEC_STATE_SAFE;
> > +             break;
> > +     default:
> > +             dev_warn(uec->dev, "unknow mode %d\n", port->mode);
> > +             break;
> > +     }
> > +
> > +     switch (port->mux) {
> > +     case USBC_MUX_NONE:
> > +             port->svid = 0;
> > +             break;
> > +     case USBC_MUX_USB_2L:
> > +             port->svid = USB_SID_PD;
> > +             port->mode = TYPEC_STATE_USB; /* same as PAN_C, correct it */
> > +             break;
> > +     case USBC_MUX_DP_4L:
> > +     case USBC_MUX_USB_DP:
> > +             port->svid = USB_SID_DISPLAYPORT;
> > +             break;
> > +     default:
> > +             dev_warn(uec->dev, "unknow mux state %d\n", port->mux);
> > +             break;
> > +     }
> > +
> > +     spin_unlock_irqrestore(&port->lock, flags);
> > +}
> > +
> > +static int gaokun_ucsi_refresh(struct gaokun_ucsi *uec)
> > +{
> > +     struct gaokun_ucsi_reg ureg;
> > +     int ret, idx;
> > +
> > +     ret = gaokun_ec_ucsi_get_reg(uec->ec, (u8 *)&ureg);
> > +     if (ret)
> > +             return GAOKUN_UCSI_NO_PORT_UPDATE;
> > +
> > +     uec->port_num = ureg.port_num;
> > +     idx = GET_IDX(ureg.port_updt);
> > +
> > +     if (idx < 0 || idx >= ureg.port_num)
> > +             return GAOKUN_UCSI_NO_PORT_UPDATE;
> > +
> > +     gaokun_ucsi_port_update(&uec->ports[idx], ureg.port_data);
> > +     return idx;
> > +}
> > +
> > +static void gaokun_ucsi_handle_altmode(struct gaokun_ucsi_port *port)
> > +{
> > +     struct gaokun_ucsi *uec = port->ucsi;
> > +     int idx = port->idx;
> > +
> > +     if (idx >= uec->ucsi->cap.num_connectors) {
> > +             dev_warn(uec->dev, "altmode port out of range: %d\n", idx);
> > +             return;
> > +     }
> > +
> > +     /* UCSI callback .connector_status() have set orientation */
> > +     if (port->bridge)
> > +             drm_aux_hpd_bridge_notify(&port->bridge->dev,
> > +                                       port->hpd_state ?
> > +                                       connector_status_connected :
> > +                                       connector_status_disconnected);
> > +
> > +     gaokun_ec_ucsi_pan_ack(uec->ec, port->idx);
> > +}
> > +
> > +static void gaokun_ucsi_altmode_notify_ind(struct gaokun_ucsi *uec)
> > +{
> > +     int idx;
> > +
> > +      if (!uec->ucsi->connector) { /* slow to register */
> > +              dev_err(uec->dev, "ucsi connector is not initialized yet\n");
> > +              return;
> > +      }
> > +
> > +     idx = gaokun_ucsi_refresh(uec);
> > +     if (idx == GAOKUN_UCSI_NO_PORT_UPDATE)
> > +             gaokun_ec_ucsi_pan_ack(uec->ec, idx); /* ack directly if no update */
> > +     else
> > +             gaokun_ucsi_handle_altmode(&uec->ports[idx]);
> > +}
> > +
> > +/*
> > + * USB event is necessary for enabling altmode, the event should follow
> > + * UCSI event, if not after timeout(this notify may be disabled somehow),
> > + * then force to enable altmode.
> > + */
> > +static void gaokun_ucsi_handle_no_usb_event(struct gaokun_ucsi *uec, int idx)
> > +{
> > +     struct gaokun_ucsi_port *port;
> > +
> > +     port = &uec->ports[idx];
> > +     if (!wait_for_completion_timeout(&port->usb_ack, 2 * HZ)) {
> > +             dev_warn(uec->dev, "No USB EVENT, triggered by UCSI EVENT");
> > +             gaokun_ucsi_altmode_notify_ind(uec);
> > +     }
> > +}
> > +
> > +static int gaokun_ucsi_notify(struct notifier_block *nb,
> > +                           unsigned long action, void *data)
> > +{
> > +     u32 cci;
> > +     struct gaokun_ucsi *uec = container_of(nb, struct gaokun_ucsi, nb);
> > +
> > +     switch (action) {
> > +     case EC_EVENT_USB:
> > +             gaokun_ucsi_altmode_notify_ind(uec);
> > +             return NOTIFY_OK;
> > +
> > +     case EC_EVENT_UCSI:
> > +             uec->ucsi->ops->read_cci(uec->ucsi, &cci);
>
> I think it would be more clear here to just call
> gaokun_ucsi_read_cci() directly here.
>

Agree

> > +             ucsi_notify_common(uec->ucsi, cci);
> > +             if (UCSI_CCI_CONNECTOR(cci))
> > +                     gaokun_ucsi_handle_no_usb_event(uec, UCSI_CCI_CONNECTOR(cci) - 1);
> > +
> > +             return NOTIFY_OK;
> > +
> > +     default:
> > +             return NOTIFY_DONE;
> > +     }
> > +}
> > +
> > +static inline int gaokun_ucsi_get_port_num(struct gaokun_ucsi *uec)
> > +{
> > +     struct gaokun_ucsi_reg ureg;
> > +     int ret;
> > +
> > +     ret = gaokun_ec_ucsi_get_reg(uec->ec, (u8 *)&ureg);
> > +
> > +     return ret ? 0 : ureg.port_num;
> > +}
>
> This function does not look like it's necessary to me.
>

Agree

> > +static int gaokun_ucsi_ports_init(struct gaokun_ucsi *uec)
> > +{
> > +     u32 port;
> > +     int i, ret, port_num;
> > +     struct device *dev = uec->dev;
> > +     struct gaokun_ucsi_port *ucsi_port;
> > +     struct fwnode_handle *fwnode;
> > +
> > +     port_num = gaokun_ucsi_get_port_num(uec);
> > +     uec->port_num = port_num;
>
> struct gaokun_ucsi_reg ureg = { };
>
> gaokun_ec_ucsi_get_reg(uec->ec, &ureg);
> port_num = ureg->port_num;
>
> (Btw. port_num here is confusing IMO, because you are not talking
> about the number of a port, but instead number of all ports. So
> something like num_ports or nports would be better).
>

Agree

> > +     uec->ports = devm_kcalloc(dev, port_num, sizeof(*(uec->ports)),
> > +                               GFP_KERNEL);
> > +     if (!uec->ports)
> > +             return -ENOMEM;
> > +
> > +     for (i = 0; i < port_num; ++i) {
> > +             ucsi_port = &uec->ports[i];
> > +             ucsi_port->ccx = USBC_CCX_NONE;
> > +             ucsi_port->idx = i;
> > +             ucsi_port->ucsi = uec;
> > +             init_completion(&ucsi_port->usb_ack);
> > +             spin_lock_init(&ucsi_port->lock);
> > +     }
> > +
> > +     device_for_each_child_node(dev, fwnode) {
> > +             ret = fwnode_property_read_u32(fwnode, "reg", &port);
> > +             if (ret < 0) {
> > +                     dev_err(dev, "missing reg property of %pOFn\n", fwnode);
> > +                     fwnode_handle_put(fwnode);
> > +                     return ret;
> > +             }
> > +
> > +             if (port >= port_num) {
> > +                     dev_warn(dev, "invalid connector number %d, ignoring\n", port);
> > +                     continue;
> > +             }
> > +
> > +             ucsi_port = &uec->ports[port];
> > +             ucsi_port->bridge = devm_drm_dp_hpd_bridge_alloc(dev, to_of_node(fwnode));
> > +             if (IS_ERR(ucsi_port->bridge)) {
> > +                     fwnode_handle_put(fwnode);
> > +                     return PTR_ERR(ucsi_port->bridge);
> > +             }
> > +     }
> > +
> > +     for (i = 0; i < port_num; i++) {
> > +             if (!uec->ports[i].bridge)
> > +                     continue;
> > +
> > +             ret = devm_drm_dp_hpd_bridge_add(dev, uec->ports[i].bridge);
> > +             if (ret)
> > +                     return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void gaokun_ucsi_register_worker(struct work_struct *work)
> > +{
> > +     struct gaokun_ucsi *uec;
> > +     struct ucsi *ucsi;
> > +     int ret;
> > +
> > +     uec = container_of(work, struct gaokun_ucsi, work.work);
> > +     ucsi = uec->ucsi;
> > +     /* This may be a problem specific to sc8280xp-based machines */
> > +     ucsi->quirks = UCSI_NO_PARTNER_PDOS | UCSI_DELAY_DEVICE_PDOS;
> > +
> > +     ret = gaokun_ec_register_notify(uec->ec, &uec->nb);
> > +     if (ret) {
> > +             dev_err_probe(ucsi->dev, ret, "notifier register failed\n");
> > +             return;
> > +     }
> > +
> > +     ret = ucsi_register(ucsi);
> > +     if (ret)
> > +             dev_err_probe(ucsi->dev, ret, "ucsi register failed\n");
> > +}
> > +
> > +static inline int gaokun_ucsi_register(struct gaokun_ucsi *uec)
> > +{
> > +     /* EC can't handle UCSI properly in the early stage */
> > +     schedule_delayed_work(&uec->work, 3 * HZ);
> > +
> > +     return 0;
> > +}
>
> This whole function is unnecessary.
>

I see, I will move it to probe function

> > +static int gaokun_ucsi_probe(struct auxiliary_device *adev,
> > +                          const struct auxiliary_device_id *id)
> > +{
> > +     struct gaokun_ec *ec = adev->dev.platform_data;
> > +     struct device *dev = &adev->dev;
> > +     struct gaokun_ucsi *uec;
> > +     int ret;
> > +
> > +     uec = devm_kzalloc(dev, sizeof(*uec), GFP_KERNEL);
> > +     if (!uec)
> > +             return -ENOMEM;
> > +
> > +     uec->ec = ec;
> > +     uec->dev = dev;
> > +     uec->version = 0x0100;
>
> Please add a definition for UCSI v1.0 to ucsi.h (separate patch).
>

Understood

> > +     uec->nb.notifier_call = gaokun_ucsi_notify;
> > +
> > +     INIT_DELAYED_WORK(&uec->work, gaokun_ucsi_register_worker);
> > +
> > +     ret = gaokun_ucsi_ports_init(uec);
> > +     if (ret)
> > +             return ret;
> > +
> > +     uec->ucsi = ucsi_create(dev, &gaokun_ucsi_ops);
> > +     if (IS_ERR(uec->ucsi))
> > +             return PTR_ERR(uec->ucsi);
> > +
> > +     ucsi_set_drvdata(uec->ucsi, uec);
> > +     auxiliary_set_drvdata(adev, uec);
> > +
> > +     return gaokun_ucsi_register(uec);
> > +}
> > +
> > +static void gaokun_ucsi_remove(struct auxiliary_device *adev)
> > +{
> > +     struct gaokun_ucsi *uec = auxiliary_get_drvdata(adev);
> > +
> > +     gaokun_ec_unregister_notify(uec->ec, &uec->nb);
> > +     ucsi_unregister(uec->ucsi);
> > +     ucsi_destroy(uec->ucsi);
> > +}
> > +
> > +static const struct auxiliary_device_id gaokun_ucsi_id_table[] = {
> > +     { .name = GAOKUN_MOD_NAME "." GAOKUN_DEV_UCSI, },
> > +     {}
> > +};
> > +MODULE_DEVICE_TABLE(auxiliary, gaokun_ucsi_id_table);
> > +
> > +static struct auxiliary_driver gaokun_ucsi_driver = {
> > +     .name = GAOKUN_DEV_UCSI,
> > +     .id_table = gaokun_ucsi_id_table,
> > +     .probe = gaokun_ucsi_probe,
> > +     .remove = gaokun_ucsi_remove,
> > +};
> > +
> > +module_auxiliary_driver(gaokun_ucsi_driver);
> > +
> > +MODULE_DESCRIPTION("HUAWEI Matebook E Go UCSI driver");
> > +MODULE_LICENSE("GPL");
>
> thanks,
>
> --
> heikki

Best wishes,
Pengyu