diff options
Diffstat (limited to 'drivers/usb/misc/ucsi.c')
| -rw-r--r-- | drivers/usb/misc/ucsi.c | 478 |
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 000000000..07397bdde --- /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"); |