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path: root/drivers/usb/misc/ucsi.c
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Diffstat (limited to 'drivers/usb/misc/ucsi.c')
-rw-r--r--drivers/usb/misc/ucsi.c478
1 files changed, 478 insertions, 0 deletions
diff --git a/drivers/usb/misc/ucsi.c b/drivers/usb/misc/ucsi.c
new file mode 100644
index 000000000000..07397bddefa3
--- /dev/null
+++ b/drivers/usb/misc/ucsi.c
@@ -0,0 +1,478 @@
+/*
+ * USB Type-C Connector System Software Interface driver
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/acpi.h>
+
+#include "ucsi.h"
+
+/* Double the time defined by MIN_TIME_TO_RESPOND_WITH_BUSY */
+#define UCSI_TIMEOUT_MS 20
+
+enum ucsi_status {
+ UCSI_IDLE = 0,
+ UCSI_BUSY,
+ UCSI_ERROR,
+};
+
+struct ucsi_connector {
+ int num;
+ struct ucsi *ucsi;
+ struct work_struct work;
+ struct ucsi_connector_capability cap;
+};
+
+struct ucsi {
+ struct device *dev;
+ struct ucsi_data __iomem *data;
+
+ enum ucsi_status status;
+ struct completion complete;
+ struct ucsi_capability cap;
+ struct ucsi_connector *connector;
+
+ /* device lock */
+ spinlock_t dev_lock;
+
+ /* PPM Communication lock */
+ struct mutex ppm_lock;
+
+ /* PPM communication flags */
+ unsigned long flags;
+#define EVENT_PENDING 0
+#define COMMAND_PENDING 1
+};
+
+static int ucsi_acpi_cmd(struct ucsi *ucsi, struct ucsi_control *ctrl)
+{
+ uuid_le uuid = UUID_LE(0x6f8398c2, 0x7ca4, 0x11e4,
+ 0xad, 0x36, 0x63, 0x10, 0x42, 0xb5, 0x00, 0x8f);
+ union acpi_object *obj;
+
+ ucsi->data->ctrl.raw_cmd = ctrl->raw_cmd;
+
+ obj = acpi_evaluate_dsm(ACPI_HANDLE(ucsi->dev), uuid.b, 1, 1, NULL);
+ if (!obj) {
+ dev_err(ucsi->dev, "%s: failed to evaluate _DSM\n", __func__);
+ return -EIO;
+ }
+
+ ACPI_FREE(obj);
+ return 0;
+}
+
+static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
+{
+ struct ucsi *ucsi = data;
+ struct ucsi_cci *cci;
+
+ spin_lock(&ucsi->dev_lock);
+
+ ucsi->status = UCSI_IDLE;
+ cci = &ucsi->data->cci;
+
+ /*
+ * REVISIT: This is not documented behavior, but all known PPMs ACK
+ * asynchronous events by sending notification with cleared CCI.
+ */
+ if (!ucsi->data->raw_cci) {
+ if (test_bit(EVENT_PENDING, &ucsi->flags))
+ complete(&ucsi->complete);
+ else
+ dev_WARN(ucsi->dev, "spurious notification\n");
+ goto out_unlock;
+ }
+
+ if (test_bit(COMMAND_PENDING, &ucsi->flags)) {
+ if (cci->busy) {
+ ucsi->status = UCSI_BUSY;
+ complete(&ucsi->complete);
+
+ goto out_unlock;
+ } else if (cci->ack_complete || cci->cmd_complete) {
+ /* Error Indication is only valid with commands */
+ if (cci->error && cci->cmd_complete)
+ ucsi->status = UCSI_ERROR;
+
+ ucsi->data->ctrl.raw_cmd = 0;
+ complete(&ucsi->complete);
+ }
+ }
+
+ if (cci->connector_change) {
+ struct ucsi_connector *con;
+
+ /*
+ * This is workaround for buggy PPMs that create asynchronous
+ * event notifications before OPM has enabled them.
+ */
+ if (!ucsi->connector)
+ goto out_unlock;
+
+ con = ucsi->connector + (cci->connector_change - 1);
+
+ /*
+ * PPM will not clear the connector specific bit in Connector
+ * Change Indication field of CCI until the driver has ACK it,
+ * and the driver can not ACK it before it has been processed.
+ * The PPM will not generate new events before the first has
+ * been acknowledged, even if they are for an other connector.
+ * So only one event at a time.
+ */
+ if (!test_and_set_bit(EVENT_PENDING, &ucsi->flags))
+ schedule_work(&con->work);
+ }
+out_unlock:
+ spin_unlock(&ucsi->dev_lock);
+}
+
+static int ucsi_ack(struct ucsi *ucsi, u8 cmd)
+{
+ struct ucsi_control ctrl;
+ int ret;
+
+ ctrl.cmd.cmd = UCSI_ACK_CC_CI;
+ ctrl.cmd.length = 0;
+ ctrl.cmd.data = cmd;
+ ret = ucsi_acpi_cmd(ucsi, &ctrl);
+ if (ret)
+ return ret;
+
+ /* Waiting for ACK also with ACK CMD for now */
+ ret = wait_for_completion_timeout(&ucsi->complete,
+ msecs_to_jiffies(UCSI_TIMEOUT_MS));
+ if (!ret)
+ return -ETIMEDOUT;
+ return 0;
+}
+
+static int ucsi_run_cmd(struct ucsi *ucsi, struct ucsi_control *ctrl,
+ void *data, size_t size)
+{
+ u16 err_value = 0;
+ int ret;
+
+ set_bit(COMMAND_PENDING, &ucsi->flags);
+
+ ret = ucsi_acpi_cmd(ucsi, ctrl);
+ if (ret)
+ goto err_clear_flag;
+
+ ret = wait_for_completion_timeout(&ucsi->complete,
+ msecs_to_jiffies(UCSI_TIMEOUT_MS));
+ if (!ret) {
+ ret = -ETIMEDOUT;
+ goto err_clear_flag;
+ }
+
+ switch (ucsi->status) {
+ case UCSI_IDLE:
+ if (data)
+ memcpy(data, ucsi->data->message_in, size);
+
+ ret = ucsi_ack(ucsi, UCSI_ACK_CMD);
+ break;
+ case UCSI_BUSY:
+ /* The caller decides whether to cancel or not */
+ ret = -EBUSY;
+ goto err_clear_flag;
+ case UCSI_ERROR:
+ ret = ucsi_ack(ucsi, UCSI_ACK_CMD);
+ if (ret)
+ goto err_clear_flag;
+
+ ctrl->cmd.cmd = UCSI_GET_ERROR_STATUS;
+ ctrl->cmd.length = 0;
+ ctrl->cmd.data = 0;
+ ret = ucsi_acpi_cmd(ucsi, ctrl);
+ if (ret)
+ goto err_clear_flag;
+
+ ret = wait_for_completion_timeout(&ucsi->complete,
+ msecs_to_jiffies(UCSI_TIMEOUT_MS));
+ if (!ret) {
+ ret = -ETIMEDOUT;
+ goto err_clear_flag;
+ }
+
+ memcpy(&err_value, ucsi->data->message_in, sizeof(err_value));
+
+ /* Something has really gone wrong */
+ if (WARN_ON(ucsi->status == UCSI_ERROR)) {
+ ret = -ENODEV;
+ goto err_clear_flag;
+ }
+
+ ret = ucsi_ack(ucsi, UCSI_ACK_CMD);
+ if (ret)
+ goto err_clear_flag;
+
+ switch (err_value) {
+ case UCSI_ERROR_INCOMPATIBLE_PARTNER:
+ ret = -EOPNOTSUPP;
+ break;
+ case UCSI_ERROR_CC_COMMUNICATION_ERR:
+ ret = -ECOMM;
+ break;
+ case UCSI_ERROR_CONTRACT_NEGOTIATION_FAIL:
+ ret = -EIO;
+ break;
+ case UCSI_ERROR_DEAD_BATTERY:
+ dev_warn(ucsi->dev, "Dead battery condition!\n");
+ ret = -EPERM;
+ break;
+ /* The following mean a bug in this driver */
+ case UCSI_ERROR_INVALID_CON_NUM:
+ case UCSI_ERROR_UNREGONIZED_CMD:
+ case UCSI_ERROR_INVALID_CMD_ARGUMENT:
+ default:
+ dev_warn(ucsi->dev,
+ "%s: possible UCSI driver bug - error %hu\n",
+ __func__, err_value);
+ ret = -EINVAL;
+ break;
+ }
+ break;
+ }
+ ctrl->raw_cmd = 0;
+err_clear_flag:
+ clear_bit(COMMAND_PENDING, &ucsi->flags);
+ return ret;
+}
+
+static void ucsi_connector_change(struct work_struct *work)
+{
+ struct ucsi_connector *con = container_of(work, struct ucsi_connector,
+ work);
+ struct ucsi_connector_status constat;
+ struct ucsi *ucsi = con->ucsi;
+ struct ucsi_control ctrl;
+ int ret;
+
+ mutex_lock(&ucsi->ppm_lock);
+
+ ctrl.cmd.cmd = UCSI_GET_CONNECTOR_STATUS;
+ ctrl.cmd.length = 0;
+ ctrl.cmd.data = con->num;
+ ret = ucsi_run_cmd(con->ucsi, &ctrl, &constat, sizeof(constat));
+ if (ret) {
+ dev_err(ucsi->dev, "%s: failed to read connector status (%d)\n",
+ __func__, ret);
+ goto out_ack_event;
+ }
+
+ /* Ignoring disconnections and Alternate Modes */
+ if (!constat.connected || !(constat.change &
+ (UCSI_CONSTAT_PARTNER_CHANGE | UCSI_CONSTAT_CONNECT_CHANGE)) ||
+ constat.partner_flags & UCSI_CONSTAT_PARTNER_FLAG_ALT_MODE)
+ goto out_ack_event;
+
+ /* If the partner got USB Host role, attempting swap */
+ if (constat.partner_type & UCSI_CONSTAT_PARTNER_TYPE_DFP) {
+ ctrl.uor.cmd = UCSI_SET_UOR;
+ ctrl.uor.con_num = con->num;
+ ctrl.uor.role = UCSI_UOR_ROLE_DFP;
+
+ ret = ucsi_run_cmd(con->ucsi, &ctrl, NULL, 0);
+ if (ret)
+ dev_err(ucsi->dev, "%s: failed to swap role (%d)\n",
+ __func__, ret);
+ }
+out_ack_event:
+ ucsi_ack(ucsi, UCSI_ACK_EVENT);
+ clear_bit(EVENT_PENDING, &ucsi->flags);
+ mutex_unlock(&ucsi->ppm_lock);
+}
+
+static int ucsi_reset_ppm(struct ucsi *ucsi)
+{
+ int timeout = UCSI_TIMEOUT_MS;
+ struct ucsi_control ctrl;
+ int ret;
+
+ memset(&ctrl, 0, sizeof(ctrl));
+ ctrl.cmd.cmd = UCSI_PPM_RESET;
+ ret = ucsi_acpi_cmd(ucsi, &ctrl);
+ if (ret)
+ return ret;
+
+ /* There is no quarantee the PPM will ever set the RESET_COMPLETE bit */
+ while (!ucsi->data->cci.reset_complete && timeout--)
+ usleep_range(1000, 2000);
+ return 0;
+}
+
+static int ucsi_init(struct ucsi *ucsi)
+{
+ struct ucsi_connector *con;
+ struct ucsi_control ctrl;
+ int ret;
+ int i;
+
+ init_completion(&ucsi->complete);
+ spin_lock_init(&ucsi->dev_lock);
+ mutex_init(&ucsi->ppm_lock);
+
+ /* Reset the PPM */
+ ret = ucsi_reset_ppm(ucsi);
+ if (ret)
+ return ret;
+
+ /*
+ * REVISIT: Executing second reset to WA an issue seen on some of the
+ * Broxton based platforms, where the first reset puts the PPM into a
+ * state where it's unable to recognise some of the commands.
+ */
+ ret = ucsi_reset_ppm(ucsi);
+ if (ret)
+ return ret;
+
+ mutex_lock(&ucsi->ppm_lock);
+
+ /* Enable basic notifications */
+ ctrl.cmd.cmd = UCSI_SET_NOTIFICATION_ENABLE;
+ ctrl.cmd.length = 0;
+ ctrl.cmd.data = UCSI_ENABLE_NTFY_CMD_COMPLETE | UCSI_ENABLE_NTFY_ERROR;
+ ret = ucsi_run_cmd(ucsi, &ctrl, NULL, 0);
+ if (ret)
+ goto err_reset;
+
+ /* Get PPM capabilities */
+ ctrl.cmd.cmd = UCSI_GET_CAPABILITY;
+ ret = ucsi_run_cmd(ucsi, &ctrl, &ucsi->cap, sizeof(ucsi->cap));
+ if (ret)
+ goto err_reset;
+
+ if (!ucsi->cap.num_connectors) {
+ ret = -ENODEV;
+ goto err_reset;
+ }
+
+ ucsi->connector = devm_kcalloc(ucsi->dev, ucsi->cap.num_connectors,
+ sizeof(*ucsi->connector), GFP_KERNEL);
+ if (!ucsi->connector) {
+ ret = -ENOMEM;
+ goto err_reset;
+ }
+
+ for (i = 1, con = ucsi->connector; i < ucsi->cap.num_connectors + 1;
+ i++, con++) {
+ /* Get connector capability */
+ ctrl.cmd.cmd = UCSI_GET_CONNECTOR_CAPABILITY;
+ ctrl.cmd.data = i;
+ ret = ucsi_run_cmd(ucsi, &ctrl, &con->cap, sizeof(con->cap));
+ if (ret)
+ goto err_reset;
+
+ con->num = i;
+ con->ucsi = ucsi;
+ INIT_WORK(&con->work, ucsi_connector_change);
+ }
+
+ /* Enable all notifications */
+ ctrl.cmd.cmd = UCSI_SET_NOTIFICATION_ENABLE;
+ ctrl.cmd.data = UCSI_ENABLE_NTFY_ALL;
+ ret = ucsi_run_cmd(ucsi, &ctrl, NULL, 0);
+ if (ret < 0)
+ goto err_reset;
+
+ mutex_unlock(&ucsi->ppm_lock);
+ return 0;
+err_reset:
+ ucsi_reset_ppm(ucsi);
+ mutex_unlock(&ucsi->ppm_lock);
+ return ret;
+}
+
+static int ucsi_acpi_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ acpi_status status;
+ struct ucsi *ucsi;
+ int ret;
+
+ ucsi = devm_kzalloc(&pdev->dev, sizeof(*ucsi), GFP_KERNEL);
+ if (!ucsi)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "missing memory resource\n");
+ return -ENODEV;
+ }
+
+ /*
+ * NOTE: ACPI has claimed the memory region as it's also an Operation
+ * Region. It's not possible to request it in the driver.
+ */
+ ucsi->data = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (!ucsi->data)
+ return -ENOMEM;
+
+ ucsi->dev = &pdev->dev;
+
+ status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev),
+ ACPI_ALL_NOTIFY,
+ ucsi_acpi_notify, ucsi);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ ret = ucsi_init(ucsi);
+ if (ret) {
+ acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
+ ACPI_ALL_NOTIFY,
+ ucsi_acpi_notify);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, ucsi);
+ return 0;
+}
+
+static int ucsi_acpi_remove(struct platform_device *pdev)
+{
+ struct ucsi *ucsi = platform_get_drvdata(pdev);
+
+ acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
+ ACPI_ALL_NOTIFY, ucsi_acpi_notify);
+
+ /* Make sure there are no events in the middle of being processed */
+ if (wait_on_bit_timeout(&ucsi->flags, EVENT_PENDING,
+ TASK_UNINTERRUPTIBLE,
+ msecs_to_jiffies(UCSI_TIMEOUT_MS)))
+ dev_WARN(ucsi->dev, "%s: Events still pending\n", __func__);
+
+ ucsi_reset_ppm(ucsi);
+ return 0;
+}
+
+static const struct acpi_device_id ucsi_acpi_match[] = {
+ { "PNP0CA0", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match);
+
+static struct platform_driver ucsi_acpi_platform_driver = {
+ .driver = {
+ .name = "ucsi_acpi",
+ .acpi_match_table = ACPI_PTR(ucsi_acpi_match),
+ },
+ .probe = ucsi_acpi_probe,
+ .remove = ucsi_acpi_remove,
+};
+
+module_platform_driver(ucsi_acpi_platform_driver);
+
+MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("USB Type-C System Software Interface (UCSI) driver");