ARM: sunxi: Add sunxi restart function via onchip watchdog

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

diff --git a/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt b/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt
new file mode 100644 (file)
index 0000000..0b27177
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt
@@ -0,0 +1,13 @@
+Allwinner sunXi Watchdog timer
+
+Required properties:
+
+- compatible : should be "allwinner,sunxi-wdt"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+wdt: watchdog@01c20c90 {
+       compatible = "allwinner,sunxi-wdt";
+       reg = <0x01c20c90 0x10>;
+};

diff --git a/arch/arm/boot/dts/sunxi.dtsi b/arch/arm/boot/dts/sunxi.dtsi
index 8284fbd7ddab7595d1cb3082ca369fee2216e79d..8bbc2bfef221a2449da1211b2b880aeb07364f94 100644 (file)
--- a/arch/arm/boot/dts/sunxi.dtsi
+++ b/arch/arm/boot/dts/sunxi.dtsi
@@ -42,11 +42,16 @@
 
                timer@01c20c00 {
                        compatible = "allwinner,sunxi-timer";
-                       reg = <0x01c20c00 0x400>;
+                       reg = <0x01c20c00 0x90>;
                        interrupts = <22>;
                        clocks = <&osc>;
                };
 
+               wdt: watchdog@01c20c90 {
+                       compatible = "allwinner,sunxi-wdt";
+                       reg = <0x01c20c90 0x10>;
+               };
+
                intc: interrupt-controller@01c20400 {
                        compatible = "allwinner,sunxi-ic";
                        reg = <0x01c20400 0x400>;

diff --git a/arch/arm/mach-sunxi/sunxi.c b/arch/arm/mach-sunxi/sunxi.c
index 13d4d96cbc85dacefc5db283594e16fc613e0ec8..dc634ae2081f2d5bb86d7806b9d040fc88497fc0 100644 (file)
--- a/arch/arm/mach-sunxi/sunxi.c
+++ b/arch/arm/mach-sunxi/sunxi.c
@@ -12,6 +12,7 @@
 
 #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>
@@ -26,6 +27,36 @@
 
 #include "sunxi.h"
 
+#define WATCHDOG_CTRL_REG      0x00
+#define WATCHDOG_MODE_REG      0x04
+
+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(3, wdt_base + WATCHDOG_MODE_REG);
+       writel(0xa57 << 1 | 1, wdt_base + WATCHDOG_CTRL_REG);
+       while(1) {
+               mdelay(5);
+               writel(3, wdt_base + WATCHDOG_MODE_REG);
+       }
+}
+
 static struct map_desc sunxi_io_desc[] __initdata = {
        {
                .virtual        = (unsigned long) SUNXI_REGS_VIRT_BASE,
@@ -42,6 +73,8 @@ void __init sunxi_map_io(void)
 
 static void __init sunxi_dt_init(void)
 {
+       sunxi_setup_restart();
+
        of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 
@@ -56,6 +89,7 @@ DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)")
        .map_io         = sunxi_map_io,
        .init_irq       = sunxi_init_irq,
        .handle_irq     = sunxi_handle_irq,
+       .restart        = sunxi_restart,
        .timer          = &sunxi_timer,
        .dt_compat      = sunxi_board_dt_compat,
 MACHINE_END