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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/interrupt.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mfd/core.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/delay.h>
#define EC_COMMAND_RETRIES 50
int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
uint8_t *out;
int csum, i;
BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
out = ec_dev->dout;
out[0] = EC_CMD_VERSION0 + msg->version;
out[1] = msg->command;
out[2] = msg->outsize;
csum = out[0] + out[1] + out[2];
for (i = 0; i < msg->outsize; i++)
csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->outdata[i];
out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff);
return EC_MSG_TX_PROTO_BYTES + msg->outsize;
}
EXPORT_SYMBOL(cros_ec_prepare_tx);
int cros_ec_check_result(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
switch (msg->result) {
case EC_RES_SUCCESS:
return 0;
case EC_RES_IN_PROGRESS:
dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
msg->command);
return -EAGAIN;
default:
dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
msg->command, msg->result);
return 0;
}
}
EXPORT_SYMBOL(cros_ec_check_result);
int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
int ret;
mutex_lock(&ec_dev->lock);
ret = ec_dev->cmd_xfer(ec_dev, msg);
if (msg->result == EC_RES_IN_PROGRESS) {
int i;
struct cros_ec_command status_msg;
struct ec_response_get_comms_status status;
status_msg.version = 0;
status_msg.command = EC_CMD_GET_COMMS_STATUS;
status_msg.outdata = NULL;
status_msg.outsize = 0;
status_msg.indata = (uint8_t *)&status;
status_msg.insize = sizeof(status);
/*
* Query the EC's status until it's no longer busy or
* we encounter an error.
*/
for (i = 0; i < EC_COMMAND_RETRIES; i++) {
usleep_range(10000, 11000);
ret = ec_dev->cmd_xfer(ec_dev, &status_msg);
if (ret < 0)
break;
msg->result = status_msg.result;
if (status_msg.result != EC_RES_SUCCESS)
break;
if (!(status.flags & EC_COMMS_STATUS_PROCESSING))
break;
}
}
mutex_unlock(&ec_dev->lock);
return ret;
}
EXPORT_SYMBOL(cros_ec_cmd_xfer);
static const struct mfd_cell cros_devs[] = {
{
.name = "cros-ec-keyb",
.id = 1,
.of_compatible = "google,cros-ec-keyb",
},
{
.name = "cros-ec-i2c-tunnel",
.id = 2,
.of_compatible = "google,cros-ec-i2c-tunnel",
},
};
int cros_ec_register(struct cros_ec_device *ec_dev)
{
struct device *dev = ec_dev->dev;
int err = 0;
if (ec_dev->din_size) {
ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
if (!ec_dev->din)
return -ENOMEM;
}
if (ec_dev->dout_size) {
ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
if (!ec_dev->dout)
return -ENOMEM;
}
mutex_init(&ec_dev->lock);
err = mfd_add_devices(dev, 0, cros_devs,
ARRAY_SIZE(cros_devs),
NULL, ec_dev->irq, NULL);
if (err) {
dev_err(dev, "failed to add mfd devices\n");
return 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;
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);
int cros_ec_resume(struct cros_ec_device *ec_dev)
{
enable_irq(ec_dev->irq);
if (ec_dev->wake_enabled) {
disable_irq_wake(ec_dev->irq);
ec_dev->wake_enabled = 0;
}
return 0;
}
EXPORT_SYMBOL(cros_ec_resume);
#endif
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ChromeOS EC core driver");
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