diff options
Diffstat (limited to 'arch/arm/mach-omap2/wd_timer.c')
-rw-r--r-- | arch/arm/mach-omap2/wd_timer.c | 56 |
1 files changed, 56 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..4067669d96c4 --- /dev/null +++ b/arch/arm/mach-omap2/wd_timer.c | |||
@@ -0,0 +1,56 @@ | |||
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 | #include "wd_timer.h" | ||
17 | |||
18 | /* | ||
19 | * In order to avoid any assumptions from bootloader regarding WDT | ||
20 | * settings, WDT module is reset during init. This enables the watchdog | ||
21 | * timer. Hence it is required to disable the watchdog after the WDT reset | ||
22 | * during init. Otherwise the system would reboot as per the default | ||
23 | * watchdog timer registers settings. | ||
24 | */ | ||
25 | #define OMAP_WDT_WPS 0x34 | ||
26 | #define OMAP_WDT_SPR 0x48 | ||
27 | |||
28 | |||
29 | int omap2_wd_timer_disable(struct omap_hwmod *oh) | ||
30 | { | ||
31 | void __iomem *base; | ||
32 | |||
33 | if (!oh) { | ||
34 | pr_err("%s: Could not look up wdtimer_hwmod\n", __func__); | ||
35 | return -EINVAL; | ||
36 | } | ||
37 | |||
38 | base = omap_hwmod_get_mpu_rt_va(oh); | ||
39 | if (!base) { | ||
40 | pr_err("%s: Could not get the base address for %s\n", | ||
41 | oh->name, __func__); | ||
42 | return -EINVAL; | ||
43 | } | ||
44 | |||
45 | /* sequence required to disable watchdog */ | ||
46 | __raw_writel(0xAAAA, base + OMAP_WDT_SPR); | ||
47 | while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) | ||
48 | cpu_relax(); | ||
49 | |||
50 | __raw_writel(0x5555, base + OMAP_WDT_SPR); | ||
51 | while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) | ||
52 | cpu_relax(); | ||
53 | |||
54 | return 0; | ||
55 | } | ||
56 | |||