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/*
* Device Tree support for Allwinner A1X SoCs
*
* Copyright (C) 2012 Maxime Ripard
*
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irqchip.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/clk/sunxi.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/system_misc.h>
#define SUN4I_WATCHDOG_CTRL_REG 0x00
#define SUN4I_WATCHDOG_CTRL_RESTART (1 << 0)
#define SUN4I_WATCHDOG_MODE_REG 0x04
#define SUN4I_WATCHDOG_MODE_ENABLE (1 << 0)
#define SUN4I_WATCHDOG_MODE_RESET_ENABLE (1 << 1)
static void __iomem *wdt_base;
static void sun4i_restart(char mode, const char *cmd)
{
if (!wdt_base)
return;
/* Enable timer and set reset bit in the watchdog */
writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
wdt_base + SUN4I_WATCHDOG_MODE_REG);
/*
* Restart the watchdog. The default (and lowest) interval
* value for the watchdog is 0.5s.
*/
writel(SUN4I_WATCHDOG_CTRL_RESTART, wdt_base + SUN4I_WATCHDOG_CTRL_REG);
while (1) {
mdelay(5);
writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
wdt_base + SUN4I_WATCHDOG_MODE_REG);
}
}
static struct of_device_id sunxi_restart_ids[] = {
{ .compatible = "allwinner,sun4i-wdt", .data = sun4i_restart },
{ /*sentinel*/ }
};
static void sunxi_setup_restart(void)
{
const struct of_device_id *of_id;
struct device_node *np;
np = of_find_matching_node(NULL, sunxi_restart_ids);
if (WARN(!np, "unable to setup watchdog restart"))
return;
wdt_base = of_iomap(np, 0);
WARN(!wdt_base, "failed to map watchdog base address");
of_id = of_match_node(sunxi_restart_ids, np);
WARN(!of_id, "restart function not available");
arm_pm_restart = of_id->data;
}
static void __init sunxi_timer_init(void)
{
sunxi_init_clocks();
clocksource_of_init();
}
static void __init sunxi_dt_init(void)
{
sunxi_setup_restart();
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
static const char * const sunxi_board_dt_compat[] = {
"allwinner,sun4i-a10",
"allwinner,sun5i-a13",
NULL,
};
DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)")
.init_machine = sunxi_dt_init,
.init_irq = irqchip_init,
.init_time = sunxi_timer_init,
.dt_compat = sunxi_board_dt_compat,
MACHINE_END
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