diff options
Diffstat (limited to 'drivers/mfd/cros_ec.c')
| -rw-r--r-- | drivers/mfd/cros_ec.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c new file mode 100644 index 000000000..65a9757a6 --- /dev/null +++ b/drivers/mfd/cros_ec.c @@ -0,0 +1,261 @@ +/* + * ChromeOS EC multi-function device + * + * Copyright (C) 2012 Google, Inc + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * 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/of_platform.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/mfd/core.h> +#include <linux/mfd/cros_ec.h> +#include <linux/suspend.h> +#include <asm/unaligned.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), +}; + +static const struct mfd_cell ec_cell = { + .name = "cros-ec-dev", + .platform_data = &ec_p, + .pdata_size = sizeof(ec_p), +}; + +static const struct mfd_cell ec_pd_cell = { + .name = "cros-ec-dev", + .platform_data = &pd_p, + .pdata_size = sizeof(pd_p), +}; + +static irqreturn_t ec_irq_thread(int irq, void *data) +{ + struct cros_ec_device *ec_dev = data; + bool wake_event = true; + int ret; + + ret = cros_ec_get_next_event(ec_dev, &wake_event); + + /* + * 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 IRQ_HANDLED; +} + +static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) +{ + struct { + struct cros_ec_command msg; + struct ec_params_host_sleep_event req; + } __packed buf; + + memset(&buf, 0, sizeof(buf)); + + buf.req.sleep_event = sleep_event; + + buf.msg.command = EC_CMD_HOST_SLEEP_EVENT; + buf.msg.version = 0; + buf.msg.outsize = sizeof(buf.req); + + return cros_ec_cmd_xfer(ec_dev, &buf.msg); +} + +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->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) { + err = devm_request_threaded_irq(dev, ec_dev->irq, NULL, + 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; + } + } + + err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1, + NULL, ec_dev->irq, NULL); + if (err) { + dev_err(dev, + "Failed to register Embedded Controller subdevice %d\n", + err); + return err; + } + + if (ec_dev->max_passthru) { + /* + * Register a PD device as well on top of this device. + * 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. + */ + err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, + &ec_pd_cell, 1, NULL, ec_dev->irq, NULL); + if (err) { + dev_err(dev, + "Failed to register Power Delivery subdevice %d\n", + err); + return err; + } + } + + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { + err = devm_of_platform_populate(dev); + if (err) { + mfd_remove_devices(dev); + dev_err(dev, "Failed to register sub-devices\n"); + return err; + } + } + + /* + * 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); + + dev_info(dev, "Chrome EC device registered\n"); + + return 0; +} +EXPORT_SYMBOL(cros_ec_register); + +int cros_ec_remove(struct cros_ec_device *ec_dev) +{ + mfd_remove_devices(ec_dev->dev); + + return 0; +} +EXPORT_SYMBOL(cros_ec_remove); + +#ifdef CONFIG_PM_SLEEP +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) +{ + while (cros_ec_get_next_event(ec_dev, NULL) > 0) + blocking_notifier_call_chain(&ec_dev->event_notifier, + 1, ec_dev); +} + +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"); |