usb: typec: ucsi: add Lenovo Yoga C630 glue driver

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

Reviewed-by: Bryan O'Donoghue <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Dmitry Baryshkov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
index bdcb1764cfae3a71852af90669c622b056504fca..680e1b87b15260fd10231c9109687a4b29315ceb 100644 (file)
--- 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 b4679f94696b6b653703b1601a201843630a24de..aed41d23887b5f7db39ed4c47b248c4412504ce5 100644 (file)
--- 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 (file)
index 0000000..8bee0b4
--- /dev/null
+++ b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
@@ -0,0 +1,204 @@
+// 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/bitops.h>
+#include <linux/completion.h>
+#include <linux/container_of.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/string.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;
+       }
+
+       switch (offset) {
+       case UCSI_CCI:
+               memcpy(val, buf, min(val_len, YOGA_C630_UCSI_CCI_SIZE));
+               return 0;
+       case UCSI_MESSAGE_IN:
+               memcpy(val, buf + YOGA_C630_UCSI_CCI_SIZE,
+                      min(val_len, YOGA_C630_UCSI_DATA_SIZE));
+               return 0;
+       default:
+               return -EINVAL;
+       }
+}
+
+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 void yoga_c630_ucsi_notify_ucsi(struct yoga_c630_ucsi *uec, u32 cci)
+{
+       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);
+}
+
+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;
+
+       switch (action) {
+       case LENOVO_EC_EVENT_USB:
+       case LENOVO_EC_EVENT_HPD:
+               ucsi_connector_change(uec->ucsi, 1);
+               return NOTIFY_OK;
+
+       case LENOVO_EC_EVENT_UCSI:
+               ret = uec->ucsi->ops->read(uec->ucsi, UCSI_CCI, &cci, sizeof(cci));
+               if (ret)
+                       return NOTIFY_DONE;
+
+               yoga_c630_ucsi_notify_ucsi(uec, cci);
+
+               return NOTIFY_OK;
+
+       default:
+               return NOTIFY_DONE;
+       }
+}
+
+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");