2 * m8xx_wdt.c - MPC8xx watchdog driver
4 * Author: Florian Schirmer <jolt@tuxbox.org>
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
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/irq.h>
15 #include <linux/kernel.h>
16 #include <linux/sched.h>
18 #include <asm/8xx_immap.h>
19 #include <syslib/m8xx_wdt.h>
21 static int wdt_timeout
;
23 static irqreturn_t
m8xx_wdt_interrupt(int, void *, struct pt_regs
*);
24 static struct irqaction m8xx_wdt_irqaction
= {
25 .handler
= m8xx_wdt_interrupt
,
29 void m8xx_wdt_reset(void)
31 volatile immap_t
*imap
= (volatile immap_t
*)IMAP_ADDR
;
33 out_be16(&imap
->im_siu_conf
.sc_swsr
, 0x556c); /* write magic1 */
34 out_be16(&imap
->im_siu_conf
.sc_swsr
, 0xaa39); /* write magic2 */
37 static irqreturn_t
m8xx_wdt_interrupt(int irq
, void *dev
, struct pt_regs
*regs
)
39 volatile immap_t
*imap
= (volatile immap_t
*)IMAP_ADDR
;
43 out_be16(&imap
->im_sit
.sit_piscr
, in_be16(&imap
->im_sit
.sit_piscr
) | PISCR_PS
); /* clear irq */
48 void __init
m8xx_wdt_handler_install(bd_t
* binfo
)
50 volatile immap_t
*imap
= (volatile immap_t
*)IMAP_ADDR
;
55 sypcr
= in_be32(&imap
->im_siu_conf
.sc_sypcr
);
57 if (!(sypcr
& 0x04)) {
58 printk(KERN_NOTICE
"m8xx_wdt: wdt disabled (SYPCR: 0x%08X)\n",
66 "m8xx_wdt: active wdt found (SWTC: 0x%04X, SWP: 0x%01X)\n",
67 (sypcr
>> 16), sypcr
& 0x01);
69 wdt_timeout
= (sypcr
>> 16) & 0xFFFF;
78 * Fire trigger if half of the wdt ticked down
81 if (imap
->im_sit
.sit_rtcsc
& RTCSC_38K
)
86 if ((wdt_timeout
) > (UINT_MAX
/ pitrtclk
))
87 pitc
= wdt_timeout
/ binfo
->bi_intfreq
* pitrtclk
/ 2;
89 pitc
= pitrtclk
* wdt_timeout
/ binfo
->bi_intfreq
/ 2;
91 out_be32(&imap
->im_sit
.sit_pitc
, pitc
<< 16);
93 out_be16(&imap
->im_sit
.sit_piscr
, (mk_int_int_mask(PIT_INTERRUPT
) << 8) | PISCR_PIE
| PISCR_PTE
);
95 if (setup_irq(PIT_INTERRUPT
, &m8xx_wdt_irqaction
))
96 panic("m8xx_wdt: error setting up the watchdog irq!");
99 "m8xx_wdt: keep-alive trigger installed (PITC: 0x%04X)\n", pitc
);
101 wdt_timeout
/= binfo
->bi_intfreq
;
104 int m8xx_wdt_get_timeout(void)