![Anders Roxell](/assets/img/avatar_default.png)
Use the helper macro for builtin drivers taht don't do anything special in driver init. This removes some boilerplate code. Link: https://lore.kernel.org/r/20200527112608.3886105-3-anders.roxell@linaro.org Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
150 lines
3.4 KiB
C
150 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
*
|
|
* Copyright (C) 2012 ARM Limited
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/vexpress.h>
|
|
|
|
static void vexpress_reset_do(struct device *dev, const char *what)
|
|
{
|
|
int err = -ENOENT;
|
|
struct regmap *reg = dev_get_drvdata(dev);
|
|
|
|
if (reg) {
|
|
err = regmap_write(reg, 0, 0);
|
|
if (!err)
|
|
mdelay(1000);
|
|
}
|
|
|
|
dev_emerg(dev, "Unable to %s (%d)\n", what, err);
|
|
}
|
|
|
|
static struct device *vexpress_power_off_device;
|
|
static atomic_t vexpress_restart_nb_refcnt = ATOMIC_INIT(0);
|
|
|
|
static void vexpress_power_off(void)
|
|
{
|
|
vexpress_reset_do(vexpress_power_off_device, "power off");
|
|
}
|
|
|
|
static struct device *vexpress_restart_device;
|
|
|
|
static int vexpress_restart(struct notifier_block *this, unsigned long mode,
|
|
void *cmd)
|
|
{
|
|
vexpress_reset_do(vexpress_restart_device, "restart");
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block vexpress_restart_nb = {
|
|
.notifier_call = vexpress_restart,
|
|
.priority = 128,
|
|
};
|
|
|
|
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;
|
|
}
|
|
|
|
static 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 const 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_register_restart_handler(struct device *dev)
|
|
{
|
|
int err;
|
|
|
|
vexpress_restart_device = dev;
|
|
if (atomic_inc_return(&vexpress_restart_nb_refcnt) == 1) {
|
|
err = register_restart_handler(&vexpress_restart_nb);
|
|
if (err) {
|
|
dev_err(dev, "cannot register restart handler (err=%d)\n", err);
|
|
atomic_dec(&vexpress_restart_nb_refcnt);
|
|
return err;
|
|
}
|
|
}
|
|
device_create_file(dev, &dev_attr_active);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int vexpress_reset_probe(struct platform_device *pdev)
|
|
{
|
|
const struct of_device_id *match =
|
|
of_match_device(vexpress_reset_of_match, &pdev->dev);
|
|
struct regmap *regmap;
|
|
int ret = 0;
|
|
|
|
if (!match)
|
|
return -EINVAL;
|
|
|
|
regmap = devm_regmap_init_vexpress_config(&pdev->dev);
|
|
if (IS_ERR(regmap))
|
|
return PTR_ERR(regmap);
|
|
dev_set_drvdata(&pdev->dev, regmap);
|
|
|
|
switch ((enum vexpress_reset_func)match->data) {
|
|
case FUNC_SHUTDOWN:
|
|
vexpress_power_off_device = &pdev->dev;
|
|
pm_power_off = vexpress_power_off;
|
|
break;
|
|
case FUNC_RESET:
|
|
if (!vexpress_restart_device)
|
|
ret = _vexpress_register_restart_handler(&pdev->dev);
|
|
break;
|
|
case FUNC_REBOOT:
|
|
ret = _vexpress_register_restart_handler(&pdev->dev);
|
|
break;
|
|
};
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct platform_driver vexpress_reset_driver = {
|
|
.probe = vexpress_reset_probe,
|
|
.driver = {
|
|
.name = "vexpress-reset",
|
|
.of_match_table = vexpress_reset_of_match,
|
|
.suppress_bind_attrs = true,
|
|
},
|
|
};
|
|
builtin_platform_driver(vexpress_reset_driver);
|