/*
* Support for periodic interrupts (100 per second) and for getting
* the current time from the RTC on Power Macintoshes.
*
* We use the decrementer register for our periodic interrupts.
*
* Paul Mackerras August 1996.
* Copyright (C) 1996 Paul Mackerras.
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/pmu.h>
#include <linux/hardirq.h>
#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/nvram.h>
/* Apparently the RTC stores seconds since 1 Jan 1904 */
#define RTC_OFFSET 2082844800
/*
* Calibrate the decrementer frequency with the VIA timer 1.
*/
#define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */
/* VIA registers */
#define RS 0x200 /* skip between registers */
#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
#define ACR (11*RS) /* Auxiliary control register */
#define IFR (13*RS) /* Interrupt flag register */
/* Bits in ACR */
#define T1MODE 0xc0 /* Timer 1 mode */
#define T1MODE_CONT 0x40 /* continuous interrupts */
/* Bits in IFR and IER */
#define T1_INT 0x40 /* Timer 1 interrupt */
extern struct timezone sys_tz;
long __init
pmac_time_init(void)
{
#ifdef CONFIG_NVRAM
s32 delta = 0;
int dst;
delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
if (delta & 0x00800000UL)
delta |= 0xFF000000UL;
dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
dst ? "on" : "off");
return delta;
#else
return 0;
#endif
}
unsigned long
pmac_get_rtc_time(void)
{
#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
struct adb_request req;
unsigned long now;
#endif
/* Get the time from the RTC */
switch (sys_ctrler) {
#ifdef CONFIG_ADB_CUDA
case SYS_CTRLER_CUDA:
if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
return 0;
while (!req.complete)
cuda_poll();
if (req.reply_len != 7)
printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
req.reply_len);
now = (req.reply[3] << 24) + (req.reply[4] << 16)
+ (req.reply[5] << 8) + req.reply[6];
return now - RTC_OFFSET;
#endif /* CONFIG_ADB_CUDA */
#ifdef CONFIG_ADB_PMU
case SYS_CTRLER_PMU:
if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
return 0;
while (!req.complete)
pmu_poll();
if (req.reply_len != 4)
printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
req.reply_len);
now = (req.reply[0] << 24) + (req.reply[1] << 16)
+ (req.reply[2] << 8) + req.reply[3];
return now - RTC_OFFSET;
#endif /* CONFIG_ADB_PMU */
default: ;
}
return 0;
}
int
pmac_set_rtc_time(unsigned long nowtime)
{
#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
struct adb_request req;
#endif
nowtime += RTC_OFFSET;
switch (sys_ctrler) {
#ifdef CONFIG_ADB_CUDA
case SYS_CTRLER_CUDA:
if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0)
return 0;
while (!req.complete)
cuda_poll();
if ((req.reply_len != 3) && (req.reply_len != 7))
printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
req.reply_len);
return 1;
#endif /* CONFIG_ADB_CUDA */
#ifdef CONFIG_ADB_PMU
case SYS_CTRLER_PMU:
if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0)
return 0;
while (!req.complete)
pmu_poll();
if (req.reply_len != 0)
printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
req.reply_len);
return 1;
#endif /* CONFIG_ADB_PMU */
default:
return 0;
}
}
/*
* Calibrate the decrementer register using VIA timer 1.
* This is used both on powermacs and CHRP machines.
*/
int __init
via_calibrate_decr(void)
{
struct device_node *vias;
volatile unsigned char __iomem *via;
int count = VIA_TIMER_FREQ_6 / 100;
unsigned int dstart, dend;
vias = find_devices("via-cuda");
if (vias == 0)
vias = find_devices("via-pmu");
if (vias == 0)
vias = find_devices("via");
if (vias == 0 || vias->n_addrs == 0)
return 0;
via = ioremap(vias->addrs[0].address, vias->addrs[0].size);
/* set timer 1 for continuous interrupts */
out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
/* set the counter to a small value */
out_8(&via[T1CH], 2);
/* set the latch to `count' */
out_8(&via[T1LL], count);
out_8(&via[T1LH], count >> 8);
/* wait until it hits 0 */
while ((in_8(&via[IFR]) & T1_INT) == 0)
;
dstart = get_dec();
/* clear the interrupt & wait until it hits 0 again */
in_8(&via[T1CL]);
while ((in_8(&via[IFR]) & T1_INT) == 0)
;
dend = get_dec();
tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100);
tb_to_us = mulhwu_scale_factor(dstart - dend, 60000);
printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n",
tb_ticks_per_jiffy, dstart - dend);
iounmap(via);
return 1;
}
#ifdef CONFIG_PM
/*
* Reset the time after a sleep.
*/
static int
time_sleep_notify(struct pmu_sleep_notifier *self, int when)
{
static unsigned long time_diff;
unsigned long flags;
unsigned long seq;
switch (when) {
case PBOOK_SLEEP_NOW:
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
time_diff = xtime.tv_sec - pmac_get_rtc_time();
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
break;
case PBOOK_WAKE:
write_seqlock_irqsave(&xtime_lock, flags);
xtime.tv_sec = pmac_get_rtc_time() + time_diff;
xtime.tv_nsec = 0;
last_rtc_update = xtime.tv_sec;
write_sequnlock_irqrestore(&xtime_lock, flags);
break;
}
return PBOOK_SLEEP_OK;
}
static struct pmu_sleep_notifier time_sleep_notifier = {
time_sleep_notify, SLEEP_LEVEL_MISC,
};
#endif /* CONFIG_PM */
/*
* Query the OF and get the decr frequency.
* This was taken from the pmac time_init() when merging the prep/pmac
* time functions.
*/
void __init
pmac_calibrate_decr(void)
{
struct device_node *cpu;
unsigned int freq, *fp;
#ifdef CONFIG_PM
pmu_register_sleep_notifier(&time_sleep_notifier);
#endif /* CONFIG_PM */
/* We assume MacRISC2 machines have correct device-tree
* calibration. That's better since the VIA itself seems
* to be slightly off. --BenH
*/
if (!machine_is_compatible("MacRISC2") &&
!machine_is_compatible("MacRISC3") &&
!machine_is_compatible("MacRISC4"))
if (via_calibrate_decr())
return;
/* Special case: QuickSilver G4s seem to have a badly calibrated
* timebase-frequency in OF, VIA is much better on these. We should
* probably implement calibration based on the KL timer on these
* machines anyway... -BenH
*/
if (machine_is_compatible("PowerMac3,5"))
if (via_calibrate_decr())
return;
/*
* The cpu node should have a timebase-frequency property
* to tell us the rate at which the decrementer counts.
*/
cpu = find_type_devices("cpu");
if (cpu == 0)
panic("can't find cpu node in time_init");
fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
if (fp == 0)
panic("can't get cpu timebase frequency");
freq = *fp;
printk("time_init: decrementer frequency = %u.%.6u MHz\n",
freq/1000000, freq%1000000);
tb_ticks_per_jiffy = freq / HZ;
tb_to_us = mulhwu_scale_factor(freq, 1000000);
}
