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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * m8xx_wdt.c - MPC8xx watchdog driver
3 *
4 * Author: Florian Schirmer <jolt@tuxbox.org>
5 *
6 * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
7 * the terms of the GNU General Public License version 2. This program
8 * is licensed "as is" without any warranty of any kind, whether express
9 * or implied.
10 */
11
12#include <linux/init.h>
13#include <linux/interrupt.h>
Tom Rinifd162302005-04-16 15:24:23 -070014#include <linux/irq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/sched.h>
Marcelo Tosattic6d950442005-11-05 13:01:16 -020017#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <asm/8xx_immap.h>
19#include <syslib/m8xx_wdt.h>
20
21static int wdt_timeout;
Marcelo Tosattifb64c242005-11-24 11:32:09 -020022int m8xx_has_internal_rtc = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
Tom Rinifd162302005-04-16 15:24:23 -070024static irqreturn_t m8xx_wdt_interrupt(int, void *, struct pt_regs *);
25static struct irqaction m8xx_wdt_irqaction = {
26 .handler = m8xx_wdt_interrupt,
27 .name = "watchdog",
28};
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030void m8xx_wdt_reset(void)
31{
32 volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
33
Marcelo Tosattic6d950442005-11-05 13:01:16 -020034 out_be16(&imap->im_siu_conf.sc_swsr, 0x556c); /* write magic1 */
35 out_be16(&imap->im_siu_conf.sc_swsr, 0xaa39); /* write magic2 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070036}
37
38static irqreturn_t m8xx_wdt_interrupt(int irq, void *dev, struct pt_regs *regs)
39{
40 volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
41
42 m8xx_wdt_reset();
43
Vitaly Bordug0ce928e2006-01-15 17:30:29 +030044 setbits16(&imap->im_sit.sit_piscr, PISCR_PS);
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 return IRQ_HANDLED;
46}
47
Marcelo Tosattifb64c242005-11-24 11:32:09 -020048#define SYPCR_SWP 0x1
49#define SYPCR_SWE 0x4
50
51
52void __init m8xx_wdt_install_irq(volatile immap_t *imap, bd_t *binfo)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 u32 pitc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 u32 pitrtclk;
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 /*
58 * Fire trigger if half of the wdt ticked down
59 */
60
61 if (imap->im_sit.sit_rtcsc & RTCSC_38K)
62 pitrtclk = 9600;
63 else
64 pitrtclk = 8192;
65
66 if ((wdt_timeout) > (UINT_MAX / pitrtclk))
67 pitc = wdt_timeout / binfo->bi_intfreq * pitrtclk / 2;
68 else
69 pitc = pitrtclk * wdt_timeout / binfo->bi_intfreq / 2;
70
Marcelo Tosattic6d950442005-11-05 13:01:16 -020071 out_be32(&imap->im_sit.sit_pitc, pitc << 16);
Marcelo Tosattie37b0c92005-10-28 17:46:10 -070072
Marcelo Tosattic6d950442005-11-05 13:01:16 -020073 out_be16(&imap->im_sit.sit_piscr, (mk_int_int_mask(PIT_INTERRUPT) << 8) | PISCR_PIE | PISCR_PTE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Tom Rinifd162302005-04-16 15:24:23 -070075 if (setup_irq(PIT_INTERRUPT, &m8xx_wdt_irqaction))
76 panic("m8xx_wdt: error setting up the watchdog irq!");
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78 printk(KERN_NOTICE
79 "m8xx_wdt: keep-alive trigger installed (PITC: 0x%04X)\n", pitc);
80
Marcelo Tosattifb64c242005-11-24 11:32:09 -020081}
82
83static void m8xx_wdt_timer_func(unsigned long data);
84
85static struct timer_list m8xx_wdt_timer =
86 TIMER_INITIALIZER(m8xx_wdt_timer_func, 0, 0);
87
88void m8xx_wdt_stop_timer(void)
89{
90 del_timer(&m8xx_wdt_timer);
91}
92
93void m8xx_wdt_install_timer(void)
94{
95 m8xx_wdt_timer.expires = jiffies + (HZ/2);
96 add_timer(&m8xx_wdt_timer);
97}
98
99static void m8xx_wdt_timer_func(unsigned long data)
100{
101 m8xx_wdt_reset();
102 m8xx_wdt_install_timer();
103}
104
105void __init m8xx_wdt_handler_install(bd_t * binfo)
106{
107 volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
108 u32 sypcr;
109
110 sypcr = in_be32(&imap->im_siu_conf.sc_sypcr);
111
112 if (!(sypcr & SYPCR_SWE)) {
113 printk(KERN_NOTICE "m8xx_wdt: wdt disabled (SYPCR: 0x%08X)\n",
114 sypcr);
115 return;
116 }
117
118 m8xx_wdt_reset();
119
120 printk(KERN_NOTICE
121 "m8xx_wdt: active wdt found (SWTC: 0x%04X, SWP: 0x%01X)\n",
122 (sypcr >> 16), sypcr & SYPCR_SWP);
123
124 wdt_timeout = (sypcr >> 16) & 0xFFFF;
125
126 if (!wdt_timeout)
127 wdt_timeout = 0xFFFF;
128
129 if (sypcr & SYPCR_SWP)
130 wdt_timeout *= 2048;
131
132 m8xx_has_internal_rtc = in_be16(&imap->im_sit.sit_rtcsc) & RTCSC_RTE;
133
134 /* if the internal RTC is off use a kernel timer */
135 if (!m8xx_has_internal_rtc) {
136 if (wdt_timeout < (binfo->bi_intfreq/HZ))
137 printk(KERN_ERR "m8xx_wdt: timeout too short for ktimer!\n");
138 m8xx_wdt_install_timer();
139 } else
140 m8xx_wdt_install_irq(imap, binfo);
141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 wdt_timeout /= binfo->bi_intfreq;
143}
144
145int m8xx_wdt_get_timeout(void)
146{
147 return wdt_timeout;
148}