1 files changed, 77 insertions, 0 deletions

diff --git a/arch/arm/mach-sunxi/sunxi.c b/arch/arm/mach-sunxi/sunxi.c
index 3f9587bb51f6..b6085084e0ff 100644
--- a/arch/arm/mach-sunxi/sunxi.c
+++ b/arch/arm/mach-sunxi/sunxi.c
@@ -12,8 +12,81 @@
 
 #include <linux/clk-provider.h>
 #include <linux/clocksource.h>
+#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 struct of_device_id sunxi_restart_ids[] = {
+        { .compatible = "allwinner,sun4i-a10-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",
@@ -23,7 +96,9 @@ static const char * const sunxi_board_dt_compat[] = {
 };
 
 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[] = {
@@ -51,5 +126,7 @@ static const char * const sun7i_board_dt_compat[] = {
 };
 
 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