[linux-2.6-block.git] / arch / ppc / syslib / m8xx_wdt.c

/*
 * m8xx_wdt.c - MPC8xx watchdog driver
 *
 * Author: Florian Schirmer <jolt@tuxbox.org>
 *
 * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/8xx_immap.h>
#include <syslib/m8xx_wdt.h>

static int wdt_timeout;
int m8xx_has_internal_rtc = 0;

static irqreturn_t m8xx_wdt_interrupt(int, void *);
static struct irqaction m8xx_wdt_irqaction = {
	.handler = m8xx_wdt_interrupt,
	.name = "watchdog",
};

void m8xx_wdt_reset(void)
{
	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;

	out_be16(&imap->im_siu_conf.sc_swsr, 0x556c);	/* write magic1 */
	out_be16(&imap->im_siu_conf.sc_swsr, 0xaa39);	/* write magic2 */
}

static irqreturn_t m8xx_wdt_interrupt(int irq, void *dev)
{
	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;

	m8xx_wdt_reset();

	setbits16(&imap->im_sit.sit_piscr, PISCR_PS);
	return IRQ_HANDLED;
}

#define SYPCR_SWP 0x1
#define SYPCR_SWE 0x4


void __init m8xx_wdt_install_irq(volatile immap_t *imap, bd_t *binfo)
{
	u32 pitc;
	u32 pitrtclk;

	/*
	 * Fire trigger if half of the wdt ticked down 
	 */

	if (imap->im_sit.sit_rtcsc & RTCSC_38K)
		pitrtclk = 9600;
	else
		pitrtclk = 8192;

	if ((wdt_timeout) > (UINT_MAX / pitrtclk))
		pitc = wdt_timeout / binfo->bi_intfreq * pitrtclk / 2;
	else
		pitc = pitrtclk * wdt_timeout / binfo->bi_intfreq / 2;

	out_be32(&imap->im_sit.sit_pitc, pitc << 16);

	out_be16(&imap->im_sit.sit_piscr, (mk_int_int_mask(PIT_INTERRUPT) << 8) | PISCR_PIE | PISCR_PTE);

	if (setup_irq(PIT_INTERRUPT, &m8xx_wdt_irqaction))
		panic("m8xx_wdt: error setting up the watchdog irq!");

	printk(KERN_NOTICE
	       "m8xx_wdt: keep-alive trigger installed (PITC: 0x%04X)\n", pitc);

}

static void m8xx_wdt_timer_func(unsigned long data);

static struct timer_list m8xx_wdt_timer =
	TIMER_INITIALIZER(m8xx_wdt_timer_func, 0, 0);

void m8xx_wdt_stop_timer(void)
{
	del_timer(&m8xx_wdt_timer);
}

void m8xx_wdt_install_timer(void)
{
	m8xx_wdt_timer.expires = jiffies + (HZ/2);
	add_timer(&m8xx_wdt_timer);
}

static void m8xx_wdt_timer_func(unsigned long data)
{
	m8xx_wdt_reset();
	m8xx_wdt_install_timer();
}

void __init m8xx_wdt_handler_install(bd_t * binfo)
{
	volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
	u32 sypcr;

	sypcr = in_be32(&imap->im_siu_conf.sc_sypcr);

	if (!(sypcr & SYPCR_SWE)) {
		printk(KERN_NOTICE "m8xx_wdt: wdt disabled (SYPCR: 0x%08X)\n",
		       sypcr);
		return;
	}

	m8xx_wdt_reset();

	printk(KERN_NOTICE
	       "m8xx_wdt: active wdt found (SWTC: 0x%04X, SWP: 0x%01X)\n",
	       (sypcr >> 16), sypcr & SYPCR_SWP);

	wdt_timeout = (sypcr >> 16) & 0xFFFF;

	if (!wdt_timeout)
		wdt_timeout = 0xFFFF;

	if (sypcr & SYPCR_SWP)
		wdt_timeout *= 2048;

	m8xx_has_internal_rtc = in_be16(&imap->im_sit.sit_rtcsc) & RTCSC_RTE;

	/* if the internal RTC is off use a kernel timer */
	if (!m8xx_has_internal_rtc) {
		if (wdt_timeout < (binfo->bi_intfreq/HZ))
			printk(KERN_ERR "m8xx_wdt: timeout too short for ktimer!\n");
		m8xx_wdt_install_timer();
	} else
		m8xx_wdt_install_irq(imap, binfo);

	wdt_timeout /= binfo->bi_intfreq;
}

int m8xx_wdt_get_timeout(void)
{
	return wdt_timeout;
}
Commit	Line	Data
1da177e4 LT	1	/*
	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>
fd16230a	14	#include <linux/irq.h>
1da177e4 LT	15	#include <linux/kernel.h>
1da177e4 LT	16	#include <linux/sched.h>
c6d95044	17	#include <asm/io.h>
1da177e4 LT	18	#include <asm/8xx_immap.h>
	19	#include <syslib/m8xx_wdt.h>
	20
	21	static int wdt_timeout;
fb64c244	22	int m8xx_has_internal_rtc = 0;
1da177e4	23
39e3eb72	24	static irqreturn_t m8xx_wdt_interrupt(int, void *);
fd16230a TR	25	static struct irqaction m8xx_wdt_irqaction = {
	26	.handler = m8xx_wdt_interrupt,
	27	.name = "watchdog",
	28	};
	29
1da177e4 LT	30	void m8xx_wdt_reset(void)
	31	{
	32	volatile immap_t imap = (volatile immap_t )IMAP_ADDR;
	33
c6d95044 MT	34	out_be16(&imap->im_siu_conf.sc_swsr, 0x556c); /* write magic1 */
c6d95044 MT	35	out_be16(&imap->im_siu_conf.sc_swsr, 0xaa39); /* write magic2 */
1da177e4 LT	36	}
1da177e4 LT	37
39e3eb72	38	static irqreturn_t m8xx_wdt_interrupt(int irq, void *dev)
1da177e4 LT	39	{
	40	volatile immap_t imap = (volatile immap_t )IMAP_ADDR;
	41
	42	m8xx_wdt_reset();
	43
0ce928e1	44	setbits16(&imap->im_sit.sit_piscr, PISCR_PS);
1da177e4 LT	45	return IRQ_HANDLED;
	46	}
	47
fb64c244 MT	48	#define SYPCR_SWP 0x1
	49	#define SYPCR_SWE 0x4
	50
	51
	52	void __init m8xx_wdt_install_irq(volatile immap_t imap, bd_t binfo)
1da177e4	53	{
1da177e4	54	u32 pitc;
1da177e4 LT	55	u32 pitrtclk;
1da177e4 LT	56
1da177e4 LT	57	/*
	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
c6d95044	71	out_be32(&imap->im_sit.sit_pitc, pitc << 16);
e37b0c96	72
c6d95044	73	out_be16(&imap->im_sit.sit_piscr, (mk_int_int_mask(PIT_INTERRUPT) << 8) \| PISCR_PIE \| PISCR_PTE);
1da177e4	74
fd16230a TR	75	if (setup_irq(PIT_INTERRUPT, &m8xx_wdt_irqaction))
fd16230a TR	76	panic("m8xx_wdt: error setting up the watchdog irq!");
1da177e4 LT	77
	78	printk(KERN_NOTICE
	79	"m8xx_wdt: keep-alive trigger installed (PITC: 0x%04X)\n", pitc);
	80
fb64c244 MT	81	}
	82
	83	static void m8xx_wdt_timer_func(unsigned long data);
	84
	85	static struct timer_list m8xx_wdt_timer =
	86	TIMER_INITIALIZER(m8xx_wdt_timer_func, 0, 0);
	87
	88	void m8xx_wdt_stop_timer(void)
	89	{
	90	del_timer(&m8xx_wdt_timer);
	91	}
	92
	93	void m8xx_wdt_install_timer(void)
	94	{
	95	m8xx_wdt_timer.expires = jiffies + (HZ/2);
	96	add_timer(&m8xx_wdt_timer);
	97	}
	98
	99	static void m8xx_wdt_timer_func(unsigned long data)
	100	{
	101	m8xx_wdt_reset();
	102	m8xx_wdt_install_timer();
	103	}
	104
	105	void __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
1da177e4 LT	142	wdt_timeout /= binfo->bi_intfreq;
	143	}
	144
	145	int m8xx_wdt_get_timeout(void)
	146	{
	147	return wdt_timeout;
	148	}