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/*
* 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 <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-ctl",
.platform_data = &ec_p,
.pdata_size = sizeof(ec_p),
};
static const struct mfd_cell ec_pd_cell = {
.name = "cros-ec-ctl",
.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;
int ret;
if (device_may_wakeup(ec_dev->dev))
pm_wakeup_event(ec_dev->dev, 0);
ret = cros_ec_get_next_event(ec_dev);
if (ret > 0)
blocking_notifier_call_chain(&ec_dev->event_notifier,
0, ec_dev);
return IRQ_HANDLED;
}
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);
cros_ec_query_all(ec_dev);
if (ec_dev->irq) {
err = request_threaded_irq(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);
goto fail_mfd;
}
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);
goto fail_mfd;
}
}
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
err = of_platform_populate(dev->of_node, NULL, NULL, dev);
if (err) {
mfd_remove_devices(dev);
dev_err(dev, "Failed to register sub-devices\n");
goto fail_mfd;
}
}
dev_info(dev, "Chrome EC device registered\n");
return 0;
fail_mfd:
if (ec_dev->irq)
free_irq(ec_dev->irq, ec_dev);
return err;
}
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;
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;
return 0;
}
EXPORT_SYMBOL(cros_ec_suspend);
static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
{
while (cros_ec_get_next_event(ec_dev) > 0)
blocking_notifier_call_chain(&ec_dev->event_notifier,
1, ec_dev);
}
int cros_ec_resume(struct cros_ec_device *ec_dev)
{
enable_irq(ec_dev->irq);
/*
* In some cases, we need to distinguish between events that occur
* during suspend if the EC is not a wake source. For example,
* keypresses during suspend should be discarded if it does not wake
* the system.
*
* If the EC is not a wake source, drain the event queue and mark them
* as "queued during suspend".
*/
if (ec_dev->wake_enabled) {
disable_irq_wake(ec_dev->irq);
ec_dev->wake_enabled = 0;
} else {
cros_ec_drain_events(ec_dev);
}
return 0;
}
EXPORT_SYMBOL(cros_ec_resume);
#endif
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ChromeOS EC core driver");
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