// SPDX-License-Identifier: GPL-2.0-only /* * ChromeOS EC multi-function device * * Copyright (C) 2012 Google, Inc * * The ChromeOS EC multi function device is used to mux all the requests * to the EC device for its multiple features: keyboard controller, * battery charging and regulator control, firmware update. */ #include #include #include #include #include #include #include #include "cros_ec.h" #define CROS_EC_DEV_EC_INDEX 0 #define CROS_EC_DEV_PD_INDEX 1 static struct cros_ec_platform ec_p = { .ec_name = CROS_EC_DEV_NAME, .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX), }; static struct cros_ec_platform pd_p = { .ec_name = CROS_EC_DEV_PD_NAME, .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX), }; /** * cros_ec_irq_handler() - top half part of the interrupt handler * @irq: IRQ id * @data: (ec_dev) Device with events to process. * * Return: Wakeup the bottom half */ static irqreturn_t cros_ec_irq_handler(int irq, void *data) { struct cros_ec_device *ec_dev = data; ec_dev->last_event_time = cros_ec_get_time_ns(); return IRQ_WAKE_THREAD; } /** * cros_ec_handle_event() - process and forward pending events on EC * @ec_dev: Device with events to process. * * Call this function in a loop when the kernel is notified that the EC has * pending events. * * Return: true if more events are still pending and this function should be * called again. */ static bool cros_ec_handle_event(struct cros_ec_device *ec_dev) { bool wake_event; bool ec_has_more_events; int ret; ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events); /* * Signal only if wake host events or any interrupt if * cros_ec_get_next_event() returned an error (default value for * wake_event is true) */ if (wake_event && device_may_wakeup(ec_dev->dev)) pm_wakeup_event(ec_dev->dev, 0); if (ret > 0) blocking_notifier_call_chain(&ec_dev->event_notifier, 0, ec_dev); return ec_has_more_events; } /** * cros_ec_irq_thread() - bottom half part of the interrupt handler * @irq: IRQ id * @data: (ec_dev) Device with events to process. * * Return: Interrupt handled. */ irqreturn_t cros_ec_irq_thread(int irq, void *data) { struct cros_ec_device *ec_dev = data; bool ec_has_more_events; do { ec_has_more_events = cros_ec_handle_event(ec_dev); } while (ec_has_more_events); return IRQ_HANDLED; } EXPORT_SYMBOL(cros_ec_irq_thread); static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) { int ret; struct { struct cros_ec_command msg; union { struct ec_params_host_sleep_event req0; struct ec_params_host_sleep_event_v1 req1; struct ec_response_host_sleep_event_v1 resp1; } u; } __packed buf; memset(&buf, 0, sizeof(buf)); if (ec_dev->host_sleep_v1) { buf.u.req1.sleep_event = sleep_event; buf.u.req1.suspend_params.sleep_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT; buf.msg.outsize = sizeof(buf.u.req1); if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) || (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME)) buf.msg.insize = sizeof(buf.u.resp1); buf.msg.version = 1; } else { buf.u.req0.sleep_event = sleep_event; buf.msg.outsize = sizeof(buf.u.req0); } buf.msg.command = EC_CMD_HOST_SLEEP_EVENT; ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg); /* Report failure to transition to system wide suspend with a warning. */ if (ret >= 0 && ec_dev->host_sleep_v1 && (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME || sleep_event == HOST_SLEEP_EVENT_S3_RESUME)) { ec_dev->last_resume_result = buf.u.resp1.resume_response.sleep_transitions; WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions & EC_HOST_RESUME_SLEEP_TIMEOUT, "EC detected sleep transition timeout. Total sleep transitions: %d", buf.u.resp1.resume_response.sleep_transitions & EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK); } return ret; } static int cros_ec_ready_event(struct notifier_block *nb, unsigned long queued_during_suspend, void *_notify) { struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device, notifier_ready); u32 host_event = cros_ec_get_host_event(ec_dev); if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) { mutex_lock(&ec_dev->lock); cros_ec_query_all(ec_dev); mutex_unlock(&ec_dev->lock); return NOTIFY_OK; } return NOTIFY_DONE; } /** * cros_ec_register() - Register a new ChromeOS EC, using the provided info. * @ec_dev: Device to register. * * Before calling this, allocate a pointer to a new device and then fill * in all the fields up to the --private-- marker. * * Return: 0 on success or negative error code. */ int cros_ec_register(struct cros_ec_device *ec_dev) { struct device *dev = ec_dev->dev; int err = 0; BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier); ec_dev->max_request = sizeof(struct ec_params_hello); ec_dev->max_response = sizeof(struct ec_response_get_protocol_info); ec_dev->max_passthru = 0; ec_dev->ec = NULL; ec_dev->pd = NULL; ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); if (!ec_dev->din) return -ENOMEM; ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); if (!ec_dev->dout) return -ENOMEM; mutex_init(&ec_dev->lock); err = cros_ec_query_all(ec_dev); if (err) { dev_err(dev, "Cannot identify the EC: error %d\n", err); return err; } if (ec_dev->irq > 0) { err = devm_request_threaded_irq(dev, ec_dev->irq, cros_ec_irq_handler, cros_ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT, "chromeos-ec", ec_dev); if (err) { dev_err(dev, "Failed to request IRQ %d: %d", ec_dev->irq, err); return err; } } /* Register a platform device for the main EC instance */ ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev", PLATFORM_DEVID_AUTO, &ec_p, sizeof(struct cros_ec_platform)); if (IS_ERR(ec_dev->ec)) { dev_err(ec_dev->dev, "Failed to create CrOS EC platform device\n"); return PTR_ERR(ec_dev->ec); } if (ec_dev->max_passthru) { /* * Register a platform device for the PD behind the main EC. * We make the following assumptions: * - behind an EC, we have a pd * - only one device added. * - the EC is responsive at init time (it is not true for a * sensor hub). */ ec_dev->pd = platform_device_register_data(ec_dev->dev, "cros-ec-dev", PLATFORM_DEVID_AUTO, &pd_p, sizeof(struct cros_ec_platform)); if (IS_ERR(ec_dev->pd)) { dev_err(ec_dev->dev, "Failed to create CrOS PD platform device\n"); err = PTR_ERR(ec_dev->pd); goto exit; } } if (IS_ENABLED(CONFIG_OF) && dev->of_node) { err = devm_of_platform_populate(dev); if (err) { dev_err(dev, "Failed to register sub-devices\n"); goto exit; } } /* * Clear sleep event - this will fail harmlessly on platforms that * don't implement the sleep event host command. */ err = cros_ec_sleep_event(ec_dev, 0); if (err < 0) dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec", err); if (ec_dev->mkbp_event_supported) { /* * Register the notifier for EC_HOST_EVENT_INTERFACE_READY * event. */ ec_dev->notifier_ready.notifier_call = cros_ec_ready_event; err = blocking_notifier_chain_register(&ec_dev->event_notifier, &ec_dev->notifier_ready); if (err) goto exit; } dev_info(dev, "Chrome EC device registered\n"); /* * Unlock EC that may be waiting for AP to process MKBP events. * If the AP takes to long to answer, the EC would stop sending events. */ if (ec_dev->mkbp_event_supported) cros_ec_irq_thread(0, ec_dev); return 0; exit: platform_device_unregister(ec_dev->ec); platform_device_unregister(ec_dev->pd); return err; } EXPORT_SYMBOL(cros_ec_register); /** * cros_ec_unregister() - Remove a ChromeOS EC. * @ec_dev: Device to unregister. * * Call this to deregister a ChromeOS EC, then clean up any private data. * * Return: 0 on success or negative error code. */ int cros_ec_unregister(struct cros_ec_device *ec_dev) { if (ec_dev->pd) platform_device_unregister(ec_dev->pd); platform_device_unregister(ec_dev->ec); return 0; } EXPORT_SYMBOL(cros_ec_unregister); #ifdef CONFIG_PM_SLEEP /** * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device. * @ec_dev: Device to suspend. * * This can be called by drivers to handle a suspend event. * * Return: 0 on success or negative error code. */ int cros_ec_suspend(struct cros_ec_device *ec_dev) { struct device *dev = ec_dev->dev; int ret; u8 sleep_event; sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? HOST_SLEEP_EVENT_S3_SUSPEND : HOST_SLEEP_EVENT_S0IX_SUSPEND; ret = cros_ec_sleep_event(ec_dev, sleep_event); if (ret < 0) dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec", ret); if (device_may_wakeup(dev)) ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); disable_irq(ec_dev->irq); ec_dev->was_wake_device = ec_dev->wake_enabled; ec_dev->suspended = true; return 0; } EXPORT_SYMBOL(cros_ec_suspend); static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev) { bool wake_event; while (ec_dev->mkbp_event_supported && cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) { blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev); if (wake_event && device_may_wakeup(ec_dev->dev)) pm_wakeup_event(ec_dev->dev, 0); } } /** * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device. * @ec_dev: Device to resume. * * This can be called by drivers to handle a resume event. * * Return: 0 on success or negative error code. */ int cros_ec_resume(struct cros_ec_device *ec_dev) { int ret; u8 sleep_event; ec_dev->suspended = false; enable_irq(ec_dev->irq); sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ? HOST_SLEEP_EVENT_S3_RESUME : HOST_SLEEP_EVENT_S0IX_RESUME; ret = cros_ec_sleep_event(ec_dev, sleep_event); if (ret < 0) dev_dbg(ec_dev->dev, "Error %d sending resume event to ec", ret); if (ec_dev->wake_enabled) { disable_irq_wake(ec_dev->irq); ec_dev->wake_enabled = 0; } /* * Let the mfd devices know about events that occur during * suspend. This way the clients know what to do with them. */ cros_ec_report_events_during_suspend(ec_dev); return 0; } EXPORT_SYMBOL(cros_ec_resume); #endif MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("ChromeOS EC core driver");