ARM: bcm281xx: Board specific reboot code

This patch adds the code needed to trigger a reboot on the bcm281xx
family.

Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Alex Elder <alex.elder@linaro.org>
Acked-by: Christian Daudt <csd@broadcom.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/arch/arm/mach-bcm/kona.c b/arch/arm/mach-bcm/kona.c
new file mode 100644
index 000000000000..6939d9017f63
--- /dev/null
+++ b/arch/arm/mach-bcm/kona.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/of_address.h>
+#include <asm/io.h>
+
+#include "kona.h"
+
+static void __iomem *watchdog_base;
+
+void bcm_kona_setup_restart(void)
+{
+        struct device_node *np_wdog;
+
+        /*
+         * The assumption is that whoever calls bcm_kona_setup_restart()
+         * also needs a Kona Watchdog Timer entry in Device Tree, i.e. we
+         * report an error if the DT entry is missing.
+         */
+        np_wdog = of_find_compatible_node(NULL, NULL, "brcm,kona-wdt");
+        if (!np_wdog) {
+                pr_err("brcm,kona-wdt not found in DT, reboot disabled\n");
+                return;
+        }
+        watchdog_base = of_iomap(np_wdog, 0);
+        WARN(!watchdog_base, "failed to map watchdog base");
+        of_node_put(np_wdog);
+}
+
+#define SECWDOG_OFFSET                  0x00000000
+#define SECWDOG_RESERVED_MASK           0xE2000000
+#define SECWDOG_WD_LOAD_FLAG_MASK       0x10000000
+#define SECWDOG_EN_MASK                 0x08000000
+#define SECWDOG_SRSTEN_MASK             0x04000000
+#define SECWDOG_CLKS_SHIFT              20
+#define SECWDOG_LOCK_SHIFT              0
+
+void bcm_kona_restart(enum reboot_mode mode, const char *cmd)
+{
+        uint32_t val;
+
+        if (!watchdog_base)
+                panic("Watchdog not mapped. Reboot failed.\n");
+
+        /* Enable watchdog2 with very short timeout. */
+        val = readl(watchdog_base + SECWDOG_OFFSET);
+        val &= SECWDOG_RESERVED_MASK | SECWDOG_WD_LOAD_FLAG_MASK;
+        val |= SECWDOG_EN_MASK | SECWDOG_SRSTEN_MASK |
+                (0x8 << SECWDOG_CLKS_SHIFT) |
+                (0x8 << SECWDOG_LOCK_SHIFT);
+        writel(val, watchdog_base + SECWDOG_OFFSET);
+
+        while (1)
+                ;
+}