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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 910df4d07e370dc0dabafaaf85417508cccf43f3 / . / drivers / watchdog / omap_wdt.c
blob: 7b1f42943293e7e5015b6e1450d820bb1c4bb427 [file] [log] [blame]
Heiko Schocher988ea352013-08-19 16:38:59 +0200[diff] [blame]1/*
2 * omap_wdt.c
3 *
4 * (C) Copyright 2013
5 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
6 *
7 * SPDX-License-Identifier: GPL-2.0
8 *
9 * Based on:
10 *
11 * Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog
12 *
13 * commit 2d991a164a61858012651e13c59521975504e260
14 * Author: Bill Pemberton <wfp5p@virginia.edu>
15 * Date: Mon Nov 19 13:21:41 2012 -0500
16 *
17 * watchdog: remove use of __devinit
18 *
19 * CONFIG_HOTPLUG is going away as an option so __devinit is no longer
20 * needed.
21 *
22 * Author: MontaVista Software, Inc.
23 * <gdavis@mvista.com> or <source@mvista.com>
24 *
25 * History:
26 *
27 * 20030527: George G. Davis <gdavis@mvista.com>
28 * Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
29 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
30 * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
31 *
32 * Copyright (c) 2004 Texas Instruments.
33 * 1. Modified to support OMAP1610 32-KHz watchdog timer
34 * 2. Ported to 2.6 kernel
35 *
36 * Copyright (c) 2005 David Brownell
37 * Use the driver model and standard identifiers; handle bigger timeouts.
38 */
39
40#include <common.h>
41#include <watchdog.h>
42#include <asm/arch/hardware.h>
43#include <asm/io.h>
44#include <asm/processor.h>
45#include <asm/arch/cpu.h>
46
47/* Hardware timeout in seconds */
48#define WDT_HW_TIMEOUT 60
49
50static unsigned int wdt_trgr_pattern = 0x1234;
51
52void hw_watchdog_reset(void)
53{
54 struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
55
56 /* wait for posted write to complete */
57 while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WTGR)
58 ;
59
60 wdt_trgr_pattern = ~wdt_trgr_pattern;
61 writel(wdt_trgr_pattern, &wdt->wdtwtgr);
62
63 /* wait for posted write to complete */
64 while ((readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WTGR))
65 ;
66}
67
68static int omap_wdt_set_timeout(unsigned int timeout)
69{
70 struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
71 u32 pre_margin = GET_WLDR_VAL(timeout);
72
73 /* just count up at 32 KHz */
74 while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR)
75 ;
76
77 writel(pre_margin, &wdt->wdtwldr);
78 while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WLDR)
79 ;
80
81 return 0;
82}
83
Lukasz Majewskib633b9c2017-02-19 23:24:38 +0100[diff] [blame]84void hw_watchdog_disable(void)
85{
86 struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
87
88 /*
89 * Disable watchdog
90 */
91 writel(0xAAAA, &wdt->wdtwspr);
92 while (readl(&wdt->wdtwwps) != 0x0)
93 ;
94 writel(0x5555, &wdt->wdtwspr);
95 while (readl(&wdt->wdtwwps) != 0x0)
96 ;
97}
98
Heiko Schocher988ea352013-08-19 16:38:59 +0200[diff] [blame]99void hw_watchdog_init(void)
100{
101 struct wd_timer *wdt = (struct wd_timer *)WDT_BASE;
102
Lukasz Majewskib633b9c2017-02-19 23:24:38 +0100[diff] [blame]103 /*
104 * Make sure the watchdog is disabled. This is unfortunately required
105 * because writing to various registers with the watchdog running has no
106 * effect.
107 */
108 hw_watchdog_disable();
109
Heiko Schocher988ea352013-08-19 16:38:59 +0200[diff] [blame]110 /* initialize prescaler */
111 while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR)
112 ;
113
114 writel(WDT_WCLR_PRE | (PTV << WDT_WCLR_PTV_OFF), &wdt->wdtwclr);
115 while (readl(&wdt->wdtwwps) & WDT_WWPS_PEND_WCLR)
116 ;
117
118 omap_wdt_set_timeout(WDT_HW_TIMEOUT);
119
120 /* Sequence to enable the watchdog */
121 writel(0xBBBB, &wdt->wdtwspr);
122 while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR)
123 ;
124
125 writel(0x4444, &wdt->wdtwspr);
126 while ((readl(&wdt->wdtwwps)) & WDT_WWPS_PEND_WSPR)
127 ;
128}