/* * 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); }