cros_ec.c
/*
* 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 = devm_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 = devm_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);
#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 (ec_dev->mkbp_event_supported &&
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");