diff options
Diffstat (limited to 'drivers/platform/chrome/cros_ec.c')
| -rw-r--r-- | drivers/platform/chrome/cros_ec.c | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c new file mode 100644 index 0000000000..badc68bbae --- /dev/null +++ b/drivers/platform/chrome/cros_ec.c @@ -0,0 +1,487 @@ +// 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 <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/slab.h> +#include <linux/suspend.h> + +#include "cros_ec.h" + +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_dev->suspend_timeout_ms; + + 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); + BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_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->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT; + + 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; + + lockdep_register_key(&ec_dev->lockdep_key); + mutex_init(&ec_dev->lock); + lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key); + + err = cros_ec_query_all(ec_dev); + if (err) { + dev_err(dev, "Cannot identify the EC: error %d\n", err); + goto exit; + } + + 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\n", + ec_dev->irq, err); + goto exit; + } + } + + /* 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"); + err = PTR_ERR(ec_dev->ec); + goto exit; + } + + 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\n", + 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); + mutex_destroy(&ec_dev->lock); + lockdep_unregister_key(&ec_dev->lockdep_key); + 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. + */ +void cros_ec_unregister(struct cros_ec_device *ec_dev) +{ + platform_device_unregister(ec_dev->pd); + platform_device_unregister(ec_dev->ec); + mutex_destroy(&ec_dev->lock); + lockdep_unregister_key(&ec_dev->lockdep_key); +} +EXPORT_SYMBOL(cros_ec_unregister); + +#ifdef CONFIG_PM_SLEEP +static void cros_ec_send_suspend_event(struct cros_ec_device *ec_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\n", + ret); +} + +/** + * cros_ec_suspend_prepare() - Handle a suspend prepare operation for the ChromeOS EC device. + * @ec_dev: Device to suspend. + * + * This can be called by drivers to handle a suspend prepare stage of suspend. + * + * Return: 0 always. + */ +int cros_ec_suspend_prepare(struct cros_ec_device *ec_dev) +{ + cros_ec_send_suspend_event(ec_dev); + return 0; +} +EXPORT_SYMBOL(cros_ec_suspend_prepare); + +static void cros_ec_disable_irq(struct cros_ec_device *ec_dev) +{ + struct device *dev = ec_dev->dev; + if (device_may_wakeup(dev)) + ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); + else + ec_dev->wake_enabled = false; + + disable_irq(ec_dev->irq); + ec_dev->suspended = true; +} + +/** + * cros_ec_suspend_late() - Handle a suspend late operation for the ChromeOS EC device. + * @ec_dev: Device to suspend. + * + * This can be called by drivers to handle a suspend late stage of suspend. + * + * Return: 0 always. + */ +int cros_ec_suspend_late(struct cros_ec_device *ec_dev) +{ + cros_ec_disable_irq(ec_dev); + return 0; +} +EXPORT_SYMBOL(cros_ec_suspend_late); + +/** + * 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 always. + */ +int cros_ec_suspend(struct cros_ec_device *ec_dev) +{ + cros_ec_send_suspend_event(ec_dev); + cros_ec_disable_irq(ec_dev); + 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); + } +} + +static void cros_ec_send_resume_event(struct cros_ec_device *ec_dev) +{ + int ret; + u8 sleep_event; + + 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\n", + ret); +} + +/** + * cros_ec_resume_complete() - Handle a resume complete operation for the ChromeOS EC device. + * @ec_dev: Device to resume. + * + * This can be called by drivers to handle a resume complete stage of resume. + */ +void cros_ec_resume_complete(struct cros_ec_device *ec_dev) +{ + cros_ec_send_resume_event(ec_dev); +} +EXPORT_SYMBOL(cros_ec_resume_complete); + +static void cros_ec_enable_irq(struct cros_ec_device *ec_dev) +{ + ec_dev->suspended = false; + enable_irq(ec_dev->irq); + + if (ec_dev->wake_enabled) + disable_irq_wake(ec_dev->irq); + + /* + * 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); +} + +/** + * cros_ec_resume_early() - Handle a resume early operation for the ChromeOS EC device. + * @ec_dev: Device to resume. + * + * This can be called by drivers to handle a resume early stage of resume. + * + * Return: 0 always. + */ +int cros_ec_resume_early(struct cros_ec_device *ec_dev) +{ + cros_ec_enable_irq(ec_dev); + return 0; +} +EXPORT_SYMBOL(cros_ec_resume_early); + +/** + * 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 always. + */ +int cros_ec_resume(struct cros_ec_device *ec_dev) +{ + cros_ec_enable_irq(ec_dev); + cros_ec_send_resume_event(ec_dev); + return 0; +} +EXPORT_SYMBOL(cros_ec_resume); + +#endif + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ChromeOS EC core driver"); |