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/*
* Copyright (c) 2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* 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.
*
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/sysfs.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/time.h>
#define S2US (1000*1000)
struct mcu_time {
struct device *dev;
unsigned gpio;
long long time_us;
};
static ssize_t mcu_time_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mcu_time *time = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lld\n", time->time_us);
}
static DEVICE_ATTR_RO(mcu_time);
static int mcu_time_sync_probe(struct platform_device *pdev)
{
int ret;
struct mcu_time *mcu_time;
struct timeval current_time;
mcu_time = devm_kzalloc(&pdev->dev, sizeof(struct mcu_time),
GFP_KERNEL);
if (!mcu_time)
return -ENOMEM;
platform_set_drvdata(pdev, mcu_time);
mcu_time->dev = &pdev->dev;
mcu_time->gpio = of_get_named_gpio(pdev->dev.of_node,
"qcom,mcu-link-gpio", 0);
if (!gpio_is_valid(mcu_time->gpio)) {
dev_err(&pdev->dev, "Invalid gpio number.\n");
return -EIO;
}
ret = devm_gpio_request(&pdev->dev, mcu_time->gpio, "mcu_gpio");
if (ret) {
dev_err(&pdev->dev, "gpio request %d failed\n", mcu_time->gpio);
return ret;
}
ret = gpio_direction_output(mcu_time->gpio, 0);
if (ret) {
dev_err(&pdev->dev, "Failed to set gpio direction output: %d\n",
mcu_time->gpio);
return ret;
}
do_gettimeofday(¤t_time);
mcu_time->time_us = current_time.tv_sec * S2US + current_time.tv_usec;
device_create_file(&pdev->dev, &dev_attr_mcu_time);
return 0;
}
static int mcu_time_sync_remove(struct platform_device *pdev)
{
device_remove_file(&pdev->dev, &dev_attr_mcu_time);
return 0;
}
static struct of_device_id mcu_time_sync_match_table[] = {
{.compatible = "qcom,mcu-time-sync"},
{},
};
static struct platform_driver mcu_time_sync_driver = {
.probe = mcu_time_sync_probe,
.remove = mcu_time_sync_remove,
.driver = {
.name = "mcu-time-sync",
.owner = THIS_MODULE,
.of_match_table = mcu_time_sync_match_table,
},
};
module_platform_driver(mcu_time_sync_driver);
MODULE_DESCRIPTION("MCU time sync driver");
MODULE_LICENSE("GPL v2");
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