[PATCH v4 3/6] usb: typec: ucsi: add Lenovo Yoga C630 glue driver

From: Dmitry Baryshkov
Date: Tue May 28 2024 - 16:47:38 EST


The Lenovo Yoga C630 WOS laptop provides implements UCSI interface in
the onboard EC. Add glue driver to interface the platform's UCSI
implementation.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/usb/typec/ucsi/Kconfig | 9 ++
drivers/usb/typec/ucsi/Makefile | 1 +
drivers/usb/typec/ucsi/ucsi_yoga_c630.c | 189 ++++++++++++++++++++++++++++++++
3 files changed, 199 insertions(+)

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index bdcb1764cfae..680e1b87b152 100644
--- a/drivers/usb/typec/ucsi/Kconfig
+++ b/drivers/usb/typec/ucsi/Kconfig
@@ -69,4 +69,13 @@ config UCSI_PMIC_GLINK
To compile the driver as a module, choose M here: the module will be
called ucsi_glink.

+config UCSI_LENOVO_YOGA_C630
+ tristate "UCSI Interface Driver for Lenovo Yoga C630"
+ depends on EC_LENOVO_YOGA_C630
+ help
+ This driver enables UCSI support on the Lenovo Yoga C630 laptop.
+
+ To compile the driver as a module, choose M here: the module will be
+ called ucsi_yoga_c630.
+
endif
diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
index b4679f94696b..aed41d23887b 100644
--- a/drivers/usb/typec/ucsi/Makefile
+++ b/drivers/usb/typec/ucsi/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o
obj-$(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
diff --git a/drivers/usb/typec/ucsi/ucsi_yoga_c630.c b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
new file mode 100644
index 000000000000..ca1ab5c81b87
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2024, Linaro Ltd
+ * Authors:
+ * Bjorn Andersson
+ * Dmitry Baryshkov
+ */
+#include <linux/auxiliary_bus.h>
+#include <linux/module.h>
+#include <linux/platform_data/lenovo-yoga-c630.h>
+
+#include "ucsi.h"
+
+struct yoga_c630_ucsi {
+ struct yoga_c630_ec *ec;
+ struct ucsi *ucsi;
+ struct notifier_block nb;
+ struct completion complete;
+ unsigned long flags;
+#define UCSI_C630_COMMAND_PENDING 0
+#define UCSI_C630_ACK_PENDING 1
+ u16 version;
+};
+
+static int yoga_c630_ucsi_read(struct ucsi *ucsi, unsigned int offset,
+ void *val, size_t val_len)
+{
+ struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
+ u8 buf[YOGA_C630_UCSI_READ_SIZE];
+ int ret;
+
+ ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
+ if (ret)
+ return ret;
+
+ if (offset == UCSI_VERSION) {
+ memcpy(val, &uec->version, min(val_len, sizeof(uec->version)));
+ return 0;
+ }
+
+ if (offset == UCSI_CCI)
+ memcpy(val, buf,
+ min(val_len, YOGA_C630_UCSI_CCI_SIZE));
+ else if (offset == UCSI_MESSAGE_IN)
+ memcpy(val, buf + YOGA_C630_UCSI_CCI_SIZE,
+ min(val_len, YOGA_C630_UCSI_DATA_SIZE));
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+static int yoga_c630_ucsi_async_write(struct ucsi *ucsi, unsigned int offset,
+ const void *val, size_t val_len)
+{
+ struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
+
+ if (offset != UCSI_CONTROL ||
+ val_len != YOGA_C630_UCSI_WRITE_SIZE)
+ return -EINVAL;
+
+ return yoga_c630_ec_ucsi_write(uec->ec, val);
+}
+
+static int yoga_c630_ucsi_sync_write(struct ucsi *ucsi, unsigned int offset,
+ const void *val, size_t val_len)
+{
+ struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
+ bool ack = UCSI_COMMAND(*(u64 *)val) == UCSI_ACK_CC_CI;
+ int ret;
+
+ if (ack)
+ set_bit(UCSI_C630_ACK_PENDING, &uec->flags);
+ else
+ set_bit(UCSI_C630_COMMAND_PENDING, &uec->flags);
+
+ reinit_completion(&uec->complete);
+
+ ret = yoga_c630_ucsi_async_write(ucsi, offset, val, val_len);
+ if (ret)
+ goto out_clear_bit;
+
+ if (!wait_for_completion_timeout(&uec->complete, 5 * HZ))
+ ret = -ETIMEDOUT;
+
+out_clear_bit:
+ if (ack)
+ clear_bit(UCSI_C630_ACK_PENDING, &uec->flags);
+ else
+ clear_bit(UCSI_C630_COMMAND_PENDING, &uec->flags);
+
+ return ret;
+}
+
+const struct ucsi_operations yoga_c630_ucsi_ops = {
+ .read = yoga_c630_ucsi_read,
+ .sync_write = yoga_c630_ucsi_sync_write,
+ .async_write = yoga_c630_ucsi_async_write,
+};
+
+static int yoga_c630_ucsi_notify(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct yoga_c630_ucsi *uec = container_of(nb, struct yoga_c630_ucsi, nb);
+ u32 cci;
+ int ret;
+
+ if (action == LENOVO_EC_EVENT_USB || action == LENOVO_EC_EVENT_HPD) {
+ ucsi_connector_change(uec->ucsi, 1);
+ return NOTIFY_OK;
+ }
+
+ if (action != LENOVO_EC_EVENT_UCSI)
+ return NOTIFY_DONE;
+
+ ret = uec->ucsi->ops->read(uec->ucsi, UCSI_CCI, &cci, sizeof(cci));
+ if (ret)
+ return NOTIFY_DONE;
+
+ if (UCSI_CCI_CONNECTOR(cci))
+ ucsi_connector_change(uec->ucsi, UCSI_CCI_CONNECTOR(cci));
+
+ if (cci & UCSI_CCI_ACK_COMPLETE &&
+ test_bit(UCSI_C630_ACK_PENDING, &uec->flags))
+ complete(&uec->complete);
+ if (cci & UCSI_CCI_COMMAND_COMPLETE &&
+ test_bit(UCSI_C630_COMMAND_PENDING, &uec->flags))
+ complete(&uec->complete);
+
+ return NOTIFY_OK;
+}
+
+static int yoga_c630_ucsi_probe(struct auxiliary_device *adev,
+ const struct auxiliary_device_id *id)
+{
+ struct yoga_c630_ec *ec = adev->dev.platform_data;
+ struct yoga_c630_ucsi *uec;
+ int ret;
+
+ uec = devm_kzalloc(&adev->dev, sizeof(*uec), GFP_KERNEL);
+ if (!uec)
+ return -ENOMEM;
+
+ uec->ec = ec;
+ init_completion(&uec->complete);
+ uec->nb.notifier_call = yoga_c630_ucsi_notify;
+
+ uec->ucsi = ucsi_create(&adev->dev, &yoga_c630_ucsi_ops);
+ if (IS_ERR(uec->ucsi))
+ return PTR_ERR(uec->ucsi);
+
+ ucsi_set_drvdata(uec->ucsi, uec);
+
+ uec->version = yoga_c630_ec_ucsi_get_version(uec->ec);
+
+ auxiliary_set_drvdata(adev, uec);
+
+ ret = yoga_c630_ec_register_notify(ec, &uec->nb);
+ if (ret)
+ return ret;
+
+ return ucsi_register(uec->ucsi);
+}
+
+static void yoga_c630_ucsi_remove(struct auxiliary_device *adev)
+{
+ struct yoga_c630_ucsi *uec = auxiliary_get_drvdata(adev);
+
+ yoga_c630_ec_unregister_notify(uec->ec, &uec->nb);
+ ucsi_unregister(uec->ucsi);
+}
+
+static const struct auxiliary_device_id yoga_c630_ucsi_id_table[] = {
+ { .name = YOGA_C630_MOD_NAME "." YOGA_C630_DEV_UCSI, },
+ {}
+};
+MODULE_DEVICE_TABLE(auxiliary, yoga_c630_ucsi_id_table);
+
+static struct auxiliary_driver yoga_c630_ucsi_driver = {
+ .name = YOGA_C630_DEV_UCSI,
+ .id_table = yoga_c630_ucsi_id_table,
+ .probe = yoga_c630_ucsi_probe,
+ .remove = yoga_c630_ucsi_remove,
+};
+
+module_auxiliary_driver(yoga_c630_ucsi_driver);
+
+MODULE_DESCRIPTION("Lenovo Yoga C630 UCSI");
+MODULE_LICENSE("GPL");

--
2.39.2