linux/drivers/power/reset/syscon-reboot.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version 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 this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] 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 this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 06:55:06 +00:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Generic Syscon Reboot Driver
*
* Copyright (c) 2013, Applied Micro Circuits Corporation
* Author: Feng Kan <fkan@apm.com>
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/notifier.h>
#include <linux/mfd/syscon.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
struct syscon_reboot_context {
struct regmap *map;
u32 offset;
u32 value;
u32 mask;
struct notifier_block restart_handler;
};
static int syscon_restart_handle(struct notifier_block *this,
unsigned long mode, void *cmd)
{
struct syscon_reboot_context *ctx =
container_of(this, struct syscon_reboot_context,
restart_handler);
/* Issue the reboot */
regmap_update_bits(ctx->map, ctx->offset, ctx->mask, ctx->value);
mdelay(1000);
pr_emerg("Unable to restart system\n");
return NOTIFY_DONE;
}
static int syscon_reboot_probe(struct platform_device *pdev)
{
struct syscon_reboot_context *ctx;
struct device *dev = &pdev->dev;
int mask_err, value_err;
int err;
ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
if (IS_ERR(ctx->map))
return PTR_ERR(ctx->map);
if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset))
return -EINVAL;
value_err = of_property_read_u32(pdev->dev.of_node, "value", &ctx->value);
mask_err = of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask);
if (value_err && mask_err) {
dev_err(dev, "unable to read 'value' and 'mask'");
return -EINVAL;
}
if (value_err) {
/* support old binding */
ctx->value = ctx->mask;
ctx->mask = 0xFFFFFFFF;
} else if (mask_err) {
/* support value without mask*/
ctx->mask = 0xFFFFFFFF;
}
ctx->restart_handler.notifier_call = syscon_restart_handle;
ctx->restart_handler.priority = 192;
err = register_restart_handler(&ctx->restart_handler);
if (err)
dev_err(dev, "can't register restart notifier (err=%d)\n", err);
return err;
}
static const struct of_device_id syscon_reboot_of_match[] = {
{ .compatible = "syscon-reboot" },
{}
};
static struct platform_driver syscon_reboot_driver = {
.probe = syscon_reboot_probe,
.driver = {
.name = "syscon-reboot",
.of_match_table = syscon_reboot_of_match,
},
};
builtin_platform_driver(syscon_reboot_driver);