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Diffstat (limited to 'drivers/watchdog/omap_wdt.c')
-rw-r--r--drivers/watchdog/omap_wdt.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
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index 0000000000..7ea4b604cd
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+++ b/drivers/watchdog/omap_wdt.c
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+/*
+ * omap_wdt.c
+ *
+ * (C) Copyright 2013
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * Based on:
+ *
+ * Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog
+ *
+ * commit 2d991a164a61858012651e13c59521975504e260
+ * Author: Bill Pemberton <wfp5p@virginia.edu>
+ * Date: Mon Nov 19 13:21:41 2012 -0500
+ *
+ * watchdog: remove use of __devinit
+ *
+ * CONFIG_HOTPLUG is going away as an option so __devinit is no longer
+ * needed.
+ *
+ * Author: MontaVista Software, Inc.
+ * <gdavis@mvista.com> or <source@mvista.com>
+ *
+ * History:
+ *
+ * 20030527: George G. Davis <gdavis@mvista.com>
+ * Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
+ * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
+ * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * Copyright (c) 2004 Texas Instruments.
+ * 1. Modified to support OMAP1610 32-KHz watchdog timer
+ * 2. Ported to 2.6 kernel
+ *
+ * Copyright (c) 2005 David Brownell
+ * Use the driver model and standard identifiers; handle bigger timeouts.
+ */
+
+#include <common.h>
+#include <watchdog.h>
+#include <asm/arch/hardware.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/arch/cpu.h>
+
+/* Hardware timeout in seconds */
+#define WDT_HW_TIMEOUT 60
+
+static unsigned int wdt_trgr_pattern = 0x1234;
+
+void hw_watchdog_reset(void)
+{
+ struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
+
+ /* wait for posted write to complete */
+ while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR)
+ ;
+
+ wdt_trgr_pattern = ~wdt_trgr_pattern;
+ writel(wdt_trgr_pattern, &wdt->wdtwtgr);
+
+ /* wait for posted write to complete */
+ while ((readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WTGR))
+ ;
+}
+
+static int omap_wdt_set_timeout(unsigned int timeout)
+{
+ struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
+ u32 pre_margin = GET_WLDR_VAL(timeout);
+
+ /* just count up at 32 KHz */
+ while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR)
+ ;
+
+ writel(pre_margin, &wdt->wdtwldr);
+ while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR)
+ ;
+
+ return 0;
+}
+
+void hw_watchdog_init(void)
+{
+ struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
+
+ /* initialize prescaler */
+ while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR)
+ ;
+
+ writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &wdt->wdtwclr);
+ while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR)
+ ;
+
+ omap_wdt_set_timeout(WDT_HW_TIMEOUT);
+
+ /* Sequence to enable the watchdog */
+ writel(0xBBBB, &wdt->wdtwspr);
+ while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR)
+ ;
+
+ writel(0x4444, &wdt->wdtwspr);
+ while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR)
+ ;
+}
+
+void hw_watchdog_disable(void)
+{
+ struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
+
+ /*
+ * Disable watchdog
+ */
+ writel(0xAAAA, &wdt->wdtwspr);
+ while (readl(&wdt->wdtwwps) != 0x0)
+ ;
+ writel(0x5555, &wdt->wdtwspr);
+ while (readl(&wdt->wdtwwps) != 0x0)
+ ;
+}