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-rw-r--r--arch/arm/mach-omap2/wd_timer.c54
1 files changed, 54 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..b0c4907ab3ca
--- /dev/null
+++ b/arch/arm/mach-omap2/wd_timer.c
@@ -0,0 +1,54 @@
1/*
2 * OMAP2+ MPU WD_TIMER-specific code
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 */
9
10#include <linux/kernel.h>
11#include <linux/io.h>
12#include <linux/err.h>
13
14#include <plat/omap_hwmod.h>
15
16/*
17 * In order to avoid any assumptions from bootloader regarding WDT
18 * settings, WDT module is reset during init. This enables the watchdog
19 * timer. Hence it is required to disable the watchdog after the WDT reset
20 * during init. Otherwise the system would reboot as per the default
21 * watchdog timer registers settings.
22 */
23#define OMAP_WDT_WPS 0x34
24#define OMAP_WDT_SPR 0x48
25
26
27int omap2_wd_timer_disable(struct omap_hwmod *oh)
28{
29 void __iomem *base;
30
31 if (!oh) {
32 pr_err("%s: Could not look up wdtimer_hwmod\n", __func__);
33 return -EINVAL;
34 }
35
36 base = omap_hwmod_get_mpu_rt_va(oh);
37 if (!base) {
38 pr_err("%s: Could not get the base address for %s\n",
39 oh->name, __func__);
40 return -EINVAL;
41 }
42
43 /* sequence required to disable watchdog */
44 __raw_writel(0xAAAA, base + OMAP_WDT_SPR);
45 while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
46 cpu_relax();
47
48 __raw_writel(0x5555, base + OMAP_WDT_SPR);
49 while (__raw_readl(base + OMAP_WDT_WPS) & 0x10)
50 cpu_relax();
51
52 return 0;
53}
54