linux/drivers/power/reset/vexpress-poweroff.c

147 lines
3.6 KiB
C
Raw Normal View History

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License 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.
*
* Copyright (C) 2012 ARM Limited
*/
#include <linux/jiffies.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/stat.h>
#include <linux/vexpress.h>
#include <asm/system_misc.h>
static void vexpress_reset_do(struct device *dev, const char *what)
{
int err = -ENOENT;
struct vexpress_config_func *func =
vexpress_config_func_get_by_dev(dev);
if (func) {
unsigned long timeout;
err = vexpress_config_write(func, 0, 0);
timeout = jiffies + HZ;
while (time_before(jiffies, timeout))
cpu_relax();
}
dev_emerg(dev, "Unable to %s (%d)\n", what, err);
}
static struct device *vexpress_power_off_device;
static void vexpress_power_off(void)
{
vexpress_reset_do(vexpress_power_off_device, "power off");
}
static struct device *vexpress_restart_device;
static void vexpress_restart(char str, const char *cmd)
{
vexpress_reset_do(vexpress_restart_device, "restart");
}
static ssize_t vexpress_reset_active_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", vexpress_restart_device == dev);
}
static ssize_t vexpress_reset_active_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
long value;
int err = kstrtol(buf, 0, &value);
if (!err && value)
vexpress_restart_device = dev;
return err ? err : count;
}
DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show,
vexpress_reset_active_store);
enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT };
static struct of_device_id vexpress_reset_of_match[] = {
{
.compatible = "arm,vexpress-reset",
.data = (void *)FUNC_RESET,
}, {
.compatible = "arm,vexpress-shutdown",
.data = (void *)FUNC_SHUTDOWN
}, {
.compatible = "arm,vexpress-reboot",
.data = (void *)FUNC_REBOOT
},
{}
};
static int vexpress_reset_probe(struct platform_device *pdev)
{
enum vexpress_reset_func func;
const struct of_device_id *match =
of_match_device(vexpress_reset_of_match, &pdev->dev);
if (match)
func = (enum vexpress_reset_func)match->data;
else
func = pdev->id_entry->driver_data;
switch (func) {
case FUNC_SHUTDOWN:
vexpress_power_off_device = &pdev->dev;
pm_power_off = vexpress_power_off;
break;
case FUNC_RESET:
if (!vexpress_restart_device)
vexpress_restart_device = &pdev->dev;
arm_pm_restart = vexpress_restart;
device_create_file(&pdev->dev, &dev_attr_active);
break;
case FUNC_REBOOT:
vexpress_restart_device = &pdev->dev;
arm_pm_restart = vexpress_restart;
device_create_file(&pdev->dev, &dev_attr_active);
break;
};
return 0;
}
static const struct platform_device_id vexpress_reset_id_table[] = {
{ .name = "vexpress-reset", .driver_data = FUNC_RESET, },
{ .name = "vexpress-shutdown", .driver_data = FUNC_SHUTDOWN, },
{ .name = "vexpress-reboot", .driver_data = FUNC_REBOOT, },
{}
};
static struct platform_driver vexpress_reset_driver = {
.probe = vexpress_reset_probe,
.driver = {
.name = "vexpress-reset",
.of_match_table = vexpress_reset_of_match,
},
.id_table = vexpress_reset_id_table,
};
static int __init vexpress_reset_init(void)
{
return platform_driver_register(&vexpress_reset_driver);
}
device_initcall(vexpress_reset_init);