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// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* Microsemi MIPS SoC reset driver
*
* License: Dual MIT/GPL
* Copyright (c) 2017 Microsemi Corporation
*/
#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 ocelot_reset_context {
void __iomem *base;
struct regmap *cpu_ctrl;
struct notifier_block restart_handler;
};
#define ICPU_CFG_CPU_SYSTEM_CTRL_RESET 0x20
#define CORE_RST_PROTECT BIT(2)
#define SOFT_CHIP_RST BIT(0)
static int ocelot_restart_handle(struct notifier_block *this,
unsigned long mode, void *cmd)
{
struct ocelot_reset_context *ctx = container_of(this, struct
ocelot_reset_context,
restart_handler);
/* Make sure the core is not protected from reset */
regmap_update_bits(ctx->cpu_ctrl, ICPU_CFG_CPU_SYSTEM_CTRL_RESET,
CORE_RST_PROTECT, 0);
writel(SOFT_CHIP_RST, ctx->base);
pr_emerg("Unable to restart system\n");
return NOTIFY_DONE;
}
static int ocelot_reset_probe(struct platform_device *pdev)
{
struct ocelot_reset_context *ctx;
struct resource *res;
struct device *dev = &pdev->dev;
int err;
ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ctx->base = devm_ioremap_resource(dev, res);
if (IS_ERR(ctx->base))
return PTR_ERR(ctx->base);
ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible("mscc,ocelot-cpu-syscon");
if (IS_ERR(ctx->cpu_ctrl))
return PTR_ERR(ctx->cpu_ctrl);
ctx->restart_handler.notifier_call = ocelot_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 ocelot_reset_of_match[] = {
{ .compatible = "mscc,ocelot-chip-reset" },
{}
};
static struct platform_driver ocelot_reset_driver = {
.probe = ocelot_reset_probe,
.driver = {
.name = "ocelot-chip-reset",
.of_match_table = ocelot_reset_of_match,
},
};
builtin_platform_driver(ocelot_reset_driver);
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