1 files changed, 100 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 0000000000..d4ea56a5f7
--- /dev/null
+++ b/arch/arm/mach-omap2/wd_timer.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OMAP2+ MPU WD_TIMER-specific code
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/err.h>
+
+#include <linux/platform_data/omap-wd-timer.h>
+
+#include "omap_hwmod.h"
+#include "omap_device.h"
+#include "wd_timer.h"
+#include "common.h"
+#include "prm.h"
+#include "soc.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;
+
+	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;
+	}
+
+	/* sequence required to disable watchdog */
+	writel_relaxed(0xAAAA, base + OMAP_WDT_SPR);
+	while (readl_relaxed(base + OMAP_WDT_WPS) & 0x10)
+		cpu_relax();
+
+	writel_relaxed(0x5555, base + OMAP_WDT_SPR);
+	while (readl_relaxed(base + OMAP_WDT_WPS) & 0x10)
+		cpu_relax();
+
+	return 0;
+}
+
+/**
+ * omap2_wdtimer_reset - reset and disable the WDTIMER IP block
+ * @oh: struct omap_hwmod *
+ *
+ * After the WDTIMER IP blocks are reset on OMAP2/3, we must also take
+ * care to execute the special watchdog disable sequence.  This is
+ * because the watchdog is re-armed upon OCP softreset.  (On OMAP4,
+ * this behavior was apparently changed and the watchdog is no longer
+ * re-armed after an OCP soft-reset.)  Returns -ETIMEDOUT if the reset
+ * did not complete, or 0 upon success.
+ *
+ * XXX Most of this code should be moved to the omap_hwmod.c layer
+ * during a normal merge window.  omap_hwmod_softreset() should be
+ * renamed to omap_hwmod_set_ocp_softreset(), and omap_hwmod_softreset()
+ * should call the hwmod _ocp_softreset() code.
+ */
+int omap2_wd_timer_reset(struct omap_hwmod *oh)
+{
+	int c = 0;
+
+	/* Write to the SOFTRESET bit */
+	omap_hwmod_softreset(oh);
+
+	/* Poll on RESETDONE bit */
+	omap_test_timeout((omap_hwmod_read(oh,
+					   oh->class->sysc->syss_offs)
+			   & SYSS_RESETDONE_MASK),
+			  MAX_MODULE_SOFTRESET_WAIT, c);
+
+	if (oh->class->sysc->srst_udelay)
+		udelay(oh->class->sysc->srst_udelay);
+
+	if (c == MAX_MODULE_SOFTRESET_WAIT)
+		pr_warn("%s: %s: softreset failed (waited %d usec)\n",
+			__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
+	else
+		pr_debug("%s: %s: softreset in %d usec\n", __func__,
+			 oh->name, c);
+
+	return (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT :
+		omap2_wd_timer_disable(oh);
+}