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Diffstat (limited to 'arch/arm/mach-bcm2835/bcm2835.c')
-rw-r--r--arch/arm/mach-bcm2835/bcm2835.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c
index f6fea4933571..c4dd210f4db1 100644
--- a/arch/arm/mach-bcm2835/bcm2835.c
+++ b/arch/arm/mach-bcm2835/bcm2835.c
@@ -12,8 +12,10 @@
* GNU General Public License for more details.
*/
+#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irqchip/bcm2835.h>
+#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/bcm2835_timer.h>
#include <linux/clk/bcm2835.h>
@@ -23,6 +25,48 @@
#include <mach/bcm2835_soc.h>
+#define PM_RSTC 0x1c
+#define PM_WDOG 0x24
+
+#define PM_PASSWORD 0x5a000000
+#define PM_RSTC_WRCFG_MASK 0x00000030
+#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
+
+static void __iomem *wdt_regs;
+
+/*
+ * The machine restart method can be called from an atomic context so we won't
+ * be able to ioremap the regs then.
+ */
+static void bcm2835_setup_restart(void)
+{
+ struct device_node *np = of_find_compatible_node(NULL, NULL,
+ "brcm,bcm2835-pm-wdt");
+ if (WARN(!np, "unable to setup watchdog restart"))
+ return;
+
+ wdt_regs = of_iomap(np, 0);
+ WARN(!wdt_regs, "failed to remap watchdog regs");
+}
+
+static void bcm2835_restart(char mode, const char *cmd)
+{
+ u32 val;
+
+ if (!wdt_regs)
+ return;
+
+ /* use a timeout of 10 ticks (~150us) */
+ writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
+ val = readl_relaxed(wdt_regs + PM_RSTC);
+ val &= ~PM_RSTC_WRCFG_MASK;
+ val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
+ writel_relaxed(val, wdt_regs + PM_RSTC);
+
+ /* No sleeping, possibly atomic. */
+ mdelay(1);
+}
+
static struct map_desc io_map __initdata = {
.virtual = BCM2835_PERIPH_VIRT,
.pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
@@ -39,6 +83,7 @@ void __init bcm2835_init(void)
{
int ret;
+ bcm2835_setup_restart();
bcm2835_init_clocks();
ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,
@@ -60,5 +105,6 @@ DT_MACHINE_START(BCM2835, "BCM2835")
.handle_irq = bcm2835_handle_irq,
.init_machine = bcm2835_init,
.timer = &bcm2835_timer,
+ .restart = bcm2835_restart,
.dt_compat = bcm2835_compat
MACHINE_END