101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
// 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)) {
|
|
ctx->map = syscon_node_to_regmap(dev->parent->of_node);
|
|
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);
|