[PATCH v3 4/6] usb: typec: ucsi: add Huawei Matebook E Go ucsi driver

Pengyu Luo
2025-01-13T17:53:09Z

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 | 11 +
drivers/usb/typec/ucsi/Makefile | 1 +
drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c | 526 ++++++++++++++++++++
3 files changed, 538 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 75559601f..e94956d27 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -91,4 +91,15 @@ 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
+ select DRM_AUX_HPD_BRIDGE
+ 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 be98a8791..dbc571763 100644
--- a/drivers/usb/typec/ucsi/Makefile
+++ b/drivers/usb/typec/ucsi/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_UCSI_STM32G0) += ucsi_stm32g0.o
obj-$(CONFIG_UCSI_PMIC_GLINK) += ucsi_glink.o
obj-$(CONFIG_CROS_EC_UCSI) += cros_ec_ucsi.o
obj-$(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..da1993805
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c
@@ -0,0 +1,527 @@
+// 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 num_ports;
+ 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 num_ports;
+};
+
+/* -------------------------------------------------------------------------- */
+/* 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->num_ports)
+ 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->num_ports) {
+ 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, "unknown 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, "unknown 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, &ureg);
+ if (ret)
+ return GAOKUN_UCSI_NO_PORT_UPDATE;
+
+ uec->num_ports = ureg.num_ports;
+ idx = GET_IDX(ureg.port_updt);
+
+ if (idx < 0 || idx >= ureg.num_ports)
+ 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]);
+}
+
+/*
+ * When inserting, 2 UCSI events(connector change) are followed by USB events.
+ * If we received one USB event, that means USB events are not blocked, so we
+ * can complelte for all ports, and we should signal all events.
+ */
+static void gaokun_ucsi_complete_usb_ack(struct gaokun_ucsi *uec)
+{
+ struct gaokun_ucsi_port *port;
+ int idx = 0;
+
+ while (idx < uec->num_ports) {
+ port = &uec->ports[idx++];
+ if (!completion_done(&port->usb_ack))
+ complete_all(&port->usb_ack);
+ }
+}
+
+/*
+ * 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_complete_usb_ack(uec);
+ gaokun_ucsi_altmode_notify_ind(uec);
+ return NOTIFY_OK;
+
+ case EC_EVENT_UCSI:
+ gaokun_ucsi_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 int gaokun_ucsi_ports_init(struct gaokun_ucsi *uec)
+{
+ struct gaokun_ucsi_port *ucsi_port;
+ struct gaokun_ucsi_reg ureg = {};
+ struct device *dev = uec->dev;
+ struct fwnode_handle *fwnode;
+ int i, ret, num_ports;
+ u32 port;
+
+ gaokun_ec_ucsi_get_reg(uec->ec, &ureg);
+ num_ports = ureg.num_ports;
+ uec->num_ports = num_ports;
+
+ uec->ports = devm_kcalloc(dev, num_ports, sizeof(*(uec->ports)),
+ GFP_KERNEL);
+ if (!uec->ports)
+ return -ENOMEM;
+
+ for (i = 0; i < num_ports; ++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 >= num_ports) {
+ 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 < num_ports; 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;
+
+ 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 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 = UCSI_VERSION_1_0;
+ 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);
+
+ /* EC can't handle UCSI properly in the early stage */
+ schedule_delayed_work(&uec->work, 3 * HZ);
+
+ return 0;
+}
+
+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