linux/drivers/power/reset/rmobile-reset.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Renesas R-Mobile Reset Driver
*
* Copyright (C) 2014 Glider bvba
*/
#include <linux/io.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/reboot.h>
/* SYSC Register Bank 2 */
#define RESCNT2 0x20 /* Reset Control Register 2 */
/* Reset Control Register 2 */
#define RESCNT2_PRES 0x80000000 /* Soft power-on reset */
static void __iomem *sysc_base2;
static int rmobile_reset_handler(struct notifier_block *this,
unsigned long mode, void *cmd)
{
pr_debug("%s %lu\n", __func__, mode);
/* Let's assume we have acquired the HPB semaphore */
writel(RESCNT2_PRES, sysc_base2 + RESCNT2);
return NOTIFY_DONE;
}
static struct notifier_block rmobile_reset_nb = {
.notifier_call = rmobile_reset_handler,
.priority = 192,
};
static int rmobile_reset_probe(struct platform_device *pdev)
{
int error;
sysc_base2 = of_iomap(pdev->dev.of_node, 1);
if (!sysc_base2)
return -ENODEV;
error = register_restart_handler(&rmobile_reset_nb);
if (error) {
dev_err(&pdev->dev,
"cannot register restart handler (err=%d)\n", error);
goto fail_unmap;
}
return 0;
fail_unmap:
iounmap(sysc_base2);
return error;
}
static int rmobile_reset_remove(struct platform_device *pdev)
{
unregister_restart_handler(&rmobile_reset_nb);
iounmap(sysc_base2);
return 0;
}
static const struct of_device_id rmobile_reset_of_match[] = {
{ .compatible = "renesas,sysc-rmobile", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rmobile_reset_of_match);
static struct platform_driver rmobile_reset_driver = {
.probe = rmobile_reset_probe,
.remove = rmobile_reset_remove,
.driver = {
.name = "rmobile_reset",
.of_match_table = rmobile_reset_of_match,
},
};
module_platform_driver(rmobile_reset_driver);
MODULE_DESCRIPTION("Renesas R-Mobile Reset Driver");
MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
MODULE_LICENSE("GPL v2");