OMAP2+: wd_timer: separate watchdog disable code from the rest of mach-omap2/devices.c

Split the wd_timer disable code out into its own file,
mach-omap2/wd_timer.c; it belongs in its own file rather than
cluttering up devices.c.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Charulatha Varadarajan <charu@ti.com>

1 files changed, 68 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/wd_timer.c b/arch/arm/mach-omap2/wd_timer.c
new file mode 100644
index 000000000000..06c256d38988
--- /dev/null
+++ b/arch/arm/mach-omap2/wd_timer.c
@@ -0,0 +1,68 @@
+/*
+ * OMAP2+ MPU WD_TIMER-specific code
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/err.h>
+
+#include <plat/omap_hwmod.h>
+
+/*
+ * In order to avoid any assumptions from bootloader regarding WDT
+ * settings, WDT module is reset during init. This enables the watchdog
+ * timer. Hence it is required to disable the watchdog after the WDT reset
+ * during init. Otherwise the system would reboot as per the default
+ * watchdog timer registers settings.
+ */
+#define OMAP_WDT_WPS		0x34
+#define OMAP_WDT_SPR		0x48
+
+
+int omap2_wd_timer_disable(struct omap_hwmod *oh)
+{
+	void __iomem *base;
+	int ret;
+
+	if (!oh) {
+		pr_err("%s: Could not look up wdtimer_hwmod\n", __func__);
+		return -EINVAL;
+	}
+
+	base = omap_hwmod_get_mpu_rt_va(oh);
+	if (!base) {
+		pr_err("%s: Could not get the base address for %s\n",
+				oh->name, __func__);
+		return -EINVAL;
+	}
+
+	/* Enable the clocks before accessing the WDT registers */
+	ret = omap_hwmod_enable(oh);
+	if (ret) {
+		pr_err("%s: Could not enable clocks for %s\n",
+				oh->name, __func__);
+		return ret;
+	}
+
+	/* sequence required to disable watchdog */
+	__raw_writel(0xAAAA, base + OMAP_WDT_SPR);
+	while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
+		cpu_relax();
+
+	__raw_writel(0x5555, base + OMAP_WDT_SPR);
+	while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
+		cpu_relax();
+
+	ret = omap_hwmod_idle(oh);
+	if (ret)
+		pr_err("%s: Could not disable clocks for %s\n",
+				oh->name, __func__);
+
+	return ret;
+}
+