/*
* 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/reboot.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 BIT(0)
#define SUN4I_WATCHDOG_MODE_REG 0x04
#define SUN4I_WATCHDOG_MODE_ENABLE BIT(0)
#define SUN4I_WATCHDOG_MODE_RESET_ENABLE BIT(1)
#define SUN6I_WATCHDOG1_IRQ_REG 0x00
#define SUN6I_WATCHDOG1_CTRL_REG 0x10
#define SUN6I_WATCHDOG1_CTRL_RESTART BIT(0)
#define SUN6I_WATCHDOG1_CONFIG_REG 0x14
#define SUN6I_WATCHDOG1_CONFIG_RESTART BIT(0)
#define SUN6I_WATCHDOG1_CONFIG_IRQ BIT(1)
#define SUN6I_WATCHDOG1_MODE_REG 0x18
#define SUN6I_WATCHDOG1_MODE_ENABLE BIT(0)
static void __iomem *wdt_base;
static void sun4i_restart(enum reboot_mode 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 void sun6i_restart(enum reboot_mode mode, const char *cmd)
{
if (!wdt_base)
return;
/* Disable interrupts */
writel(0, wdt_base + SUN6I_WATCHDOG1_IRQ_REG);
/* We want to disable the IRQ and just reset the whole system */
writel(SUN6I_WATCHDOG1_CONFIG_RESTART,
wdt_base + SUN6I_WATCHDOG1_CONFIG_REG);
/* Enable timer. The default and lowest interval value is 0.5s */
writel(SUN6I_WATCHDOG1_MODE_ENABLE,
wdt_base + SUN6I_WATCHDOG1_MODE_REG);
/* Restart the watchdog. */
writel(SUN6I_WATCHDOG1_CTRL_RESTART,
wdt_base + SUN6I_WATCHDOG1_CTRL_REG);
while (1) {
mdelay(5);
writel(SUN6I_WATCHDOG1_MODE_ENABLE,
wdt_base + SUN6I_WATCHDOG1_MODE_REG);
}
}
static struct of_device_id sunxi_restart_ids[] = {
{ .compatible = "allwinner,sun4i-wdt" },
{ .compatible = "allwinner,sun6i-wdt" },
{ /*sentinel*/ }
};
static void sunxi_setup_restart(void)
{
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");
}
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-a10s",
"allwinner,sun5i-a13",
NULL,
};
DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)")
.init_machine = sunxi_dt_init,
.dt_compat = sunxi_board_dt_compat,
.restart = sun4i_restart,
MACHINE_END
static const char * const sun6i_board_dt_compat[] = {
"allwinner,sun6i-a31",
NULL,
};
DT_MACHINE_START(SUN6I_DT, "Allwinner sun6i (A31) Family")
.init_machine = sunxi_dt_init,
.dt_compat = sun6i_board_dt_compat,
.restart = sun6i_restart,
MACHINE_END
static const char * const sun7i_board_dt_compat[] = {
"allwinner,sun7i-a20",
NULL,
};
DT_MACHINE_START(SUN7I_DT, "Allwinner sun7i (A20) Family")
.init_machine = sunxi_dt_init,
.dt_compat = sun7i_board_dt_compat,
.restart = sun4i_restart,
MACHINE_END
