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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 Pengutronix, Ahmad Fatoum <a.fatoum@pengutronix.de>
*/
#include <common.h>
#include <init.h>
#include <io.h>
#include <restart.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <mach/at91_rstc.h>
#include <reset_source.h>
struct at91sam9x_rst {
struct restart_handler restart;
void __iomem *base;
};
static int reasons[] = {
RESET_POR, /* GENERAL Both VDDCORE and VDDBU rising */
RESET_WKE, /* WAKEUP VDDCORE rising */
RESET_WDG, /* WATCHDOG Watchdog fault occurred */
RESET_RST, /* SOFTWARE Reset required by the software */
RESET_EXT, /* USER NRST pin detected low */
};
static void at91sam9x_set_reset_reason(struct device_d *dev,
void __iomem *base)
{
enum reset_src_type type = RESET_UKWN;
u32 sr, rsttyp;
sr = readl(base + AT91_RSTC_SR);
rsttyp = FIELD_GET(AT91_RSTC_RSTTYP, sr);
if (rsttyp < ARRAY_SIZE(reasons))
type = reasons[rsttyp];
dev_info(dev, "reset reason %s (RSTC_SR: 0x%05x)\n",
reset_source_to_string(type), sr);
reset_source_set(type);
}
static void __noreturn at91sam9x_restart_soc(struct restart_handler *rst)
{
struct at91sam9x_rst *priv = container_of(rst, struct at91sam9x_rst, restart);
writel(AT91_RSTC_PROCRST
| AT91_RSTC_PERRST
| AT91_RSTC_EXTRST
| AT91_RSTC_KEY,
priv->base + AT91_RSTC_CR);
hang();
}
static int at91sam9x_rst_probe(struct device_d *dev)
{
struct at91sam9x_rst *priv;
struct resource *iores;
struct clk *clk;
iores = dev_request_mem_resource(dev, 0);
if (IS_ERR(iores)) {
dev_err(dev, "could not get reset memory region\n");
return PTR_ERR(iores);
}
priv = xzalloc(sizeof(*priv));
priv->base = IOMEM(iores->start);
clk = clk_get(dev, NULL);
if (IS_ERR(clk)) {
release_region(iores);
free(priv);
return PTR_ERR(clk);
}
clk_enable(clk);
at91sam9x_set_reset_reason(dev, priv->base);
priv->restart.name = "at91sam9x-rst";
priv->restart.restart = at91sam9x_restart_soc;
return restart_handler_register(&priv->restart);
}
static const __maybe_unused struct of_device_id at91sam9x_rst_dt_ids[] = {
{ .compatible = "atmel,at91sam9g45-rstc", },
{ .compatible = "atmel,sama5d3-rstc", },
{ /* sentinel */ },
};
static struct driver_d at91sam9x_rst_driver = {
.name = "at91sam9x-rst",
.of_compatible = DRV_OF_COMPAT(at91sam9x_rst_dt_ids),
.probe = at91sam9x_rst_probe,
};
device_platform_driver(at91sam9x_rst_driver);
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