linux/arch/arm/mach-sunxi/sunxi.c

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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/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/sunxi_timer.h>
#include <linux/irqchip/sunxi.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include "sunxi.h"
#define WATCHDOG_CTRL_REG 0x00
#define WATCHDOG_CTRL_RESTART (1 << 0)
#define WATCHDOG_MODE_REG 0x04
#define WATCHDOG_MODE_ENABLE (1 << 0)
#define WATCHDOG_MODE_RESET_ENABLE (1 << 1)
static void __iomem *wdt_base;
static void sunxi_setup_restart(void)
{
struct device_node *np = of_find_compatible_node(NULL, NULL,
"allwinner,sunxi-wdt");
if (WARN(!np, "unable to setup watchdog restart"))
return;
wdt_base = of_iomap(np, 0);
WARN(!wdt_base, "failed to map watchdog base address");
}
static void sunxi_restart(char mode, const char *cmd)
{
if (!wdt_base)
return;
/* Enable timer and set reset bit in the watchdog */
writel(WATCHDOG_MODE_ENABLE | WATCHDOG_MODE_RESET_ENABLE,
wdt_base + WATCHDOG_MODE_REG);
/*
* Restart the watchdog. The default (and lowest) interval
* value for the watchdog is 0.5s.
*/
writel(WATCHDOG_CTRL_RESTART, wdt_base + WATCHDOG_CTRL_REG);
while (1) {
mdelay(5);
writel(WATCHDOG_MODE_ENABLE | WATCHDOG_MODE_RESET_ENABLE,
wdt_base + WATCHDOG_MODE_REG);
}
}
static struct map_desc sunxi_io_desc[] __initdata = {
{
.virtual = (unsigned long) SUNXI_REGS_VIRT_BASE,
.pfn = __phys_to_pfn(SUNXI_REGS_PHYS_BASE),
.length = SUNXI_REGS_SIZE,
.type = MT_DEVICE,
},
};
void __init sunxi_map_io(void)
{
iotable_init(sunxi_io_desc, ARRAY_SIZE(sunxi_io_desc));
}
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,
.map_io = sunxi_map_io,
.init_irq = sunxi_init_irq,
.handle_irq = sunxi_handle_irq,
.restart = sunxi_restart,
.init_time = &sunxi_timer_init,
.dt_compat = sunxi_board_dt_compat,
MACHINE_END