1f6d57916SPaul Mackerras /* 2f6d57916SPaul Mackerras * Support for periodic interrupts (100 per second) and for getting 3f6d57916SPaul Mackerras * the current time from the RTC on Power Macintoshes. 4f6d57916SPaul Mackerras * 5f6d57916SPaul Mackerras * We use the decrementer register for our periodic interrupts. 6f6d57916SPaul Mackerras * 7f6d57916SPaul Mackerras * Paul Mackerras August 1996. 8f6d57916SPaul Mackerras * Copyright (C) 1996 Paul Mackerras. 9f6d57916SPaul Mackerras */ 10f6d57916SPaul Mackerras #include <linux/config.h> 11f6d57916SPaul Mackerras #include <linux/errno.h> 12f6d57916SPaul Mackerras #include <linux/sched.h> 13f6d57916SPaul Mackerras #include <linux/kernel.h> 14f6d57916SPaul Mackerras #include <linux/param.h> 15f6d57916SPaul Mackerras #include <linux/string.h> 16f6d57916SPaul Mackerras #include <linux/mm.h> 17f6d57916SPaul Mackerras #include <linux/init.h> 18f6d57916SPaul Mackerras #include <linux/time.h> 19f6d57916SPaul Mackerras #include <linux/adb.h> 20f6d57916SPaul Mackerras #include <linux/cuda.h> 21f6d57916SPaul Mackerras #include <linux/pmu.h> 22f6d57916SPaul Mackerras #include <linux/hardirq.h> 23f6d57916SPaul Mackerras 24f6d57916SPaul Mackerras #include <asm/sections.h> 25f6d57916SPaul Mackerras #include <asm/prom.h> 26f6d57916SPaul Mackerras #include <asm/system.h> 27f6d57916SPaul Mackerras #include <asm/io.h> 28f6d57916SPaul Mackerras #include <asm/pgtable.h> 29f6d57916SPaul Mackerras #include <asm/machdep.h> 30f6d57916SPaul Mackerras #include <asm/time.h> 31f6d57916SPaul Mackerras #include <asm/nvram.h> 32f6d57916SPaul Mackerras 33f6d57916SPaul Mackerras /* Apparently the RTC stores seconds since 1 Jan 1904 */ 34f6d57916SPaul Mackerras #define RTC_OFFSET 2082844800 35f6d57916SPaul Mackerras 36f6d57916SPaul Mackerras /* 37f6d57916SPaul Mackerras * Calibrate the decrementer frequency with the VIA timer 1. 38f6d57916SPaul Mackerras */ 39f6d57916SPaul Mackerras #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */ 40f6d57916SPaul Mackerras 41f6d57916SPaul Mackerras /* VIA registers */ 42f6d57916SPaul Mackerras #define RS 0x200 /* skip between registers */ 43f6d57916SPaul Mackerras #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 44f6d57916SPaul Mackerras #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 45f6d57916SPaul Mackerras #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 46f6d57916SPaul Mackerras #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 47f6d57916SPaul Mackerras #define ACR (11*RS) /* Auxiliary control register */ 48f6d57916SPaul Mackerras #define IFR (13*RS) /* Interrupt flag register */ 49f6d57916SPaul Mackerras 50f6d57916SPaul Mackerras /* Bits in ACR */ 51f6d57916SPaul Mackerras #define T1MODE 0xc0 /* Timer 1 mode */ 52f6d57916SPaul Mackerras #define T1MODE_CONT 0x40 /* continuous interrupts */ 53f6d57916SPaul Mackerras 54f6d57916SPaul Mackerras /* Bits in IFR and IER */ 55f6d57916SPaul Mackerras #define T1_INT 0x40 /* Timer 1 interrupt */ 56f6d57916SPaul Mackerras 57f6d57916SPaul Mackerras extern struct timezone sys_tz; 58f6d57916SPaul Mackerras 59f6d57916SPaul Mackerras long __init 60f6d57916SPaul Mackerras pmac_time_init(void) 61f6d57916SPaul Mackerras { 62f6d57916SPaul Mackerras #ifdef CONFIG_NVRAM 63f6d57916SPaul Mackerras s32 delta = 0; 64f6d57916SPaul Mackerras int dst; 65f6d57916SPaul Mackerras 66f6d57916SPaul Mackerras delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16; 67f6d57916SPaul Mackerras delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8; 68f6d57916SPaul Mackerras delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb); 69f6d57916SPaul Mackerras if (delta & 0x00800000UL) 70f6d57916SPaul Mackerras delta |= 0xFF000000UL; 71f6d57916SPaul Mackerras dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0); 72f6d57916SPaul Mackerras printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60, 73f6d57916SPaul Mackerras dst ? "on" : "off"); 74f6d57916SPaul Mackerras return delta; 75f6d57916SPaul Mackerras #else 76f6d57916SPaul Mackerras return 0; 77f6d57916SPaul Mackerras #endif 78f6d57916SPaul Mackerras } 79f6d57916SPaul Mackerras 80f6d57916SPaul Mackerras unsigned long 81f6d57916SPaul Mackerras pmac_get_rtc_time(void) 82f6d57916SPaul Mackerras { 83f6d57916SPaul Mackerras #if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) 84f6d57916SPaul Mackerras struct adb_request req; 85f6d57916SPaul Mackerras unsigned long now; 86f6d57916SPaul Mackerras #endif 87f6d57916SPaul Mackerras 88f6d57916SPaul Mackerras /* Get the time from the RTC */ 89f6d57916SPaul Mackerras switch (sys_ctrler) { 90f6d57916SPaul Mackerras #ifdef CONFIG_ADB_CUDA 91f6d57916SPaul Mackerras case SYS_CTRLER_CUDA: 92f6d57916SPaul Mackerras if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0) 93f6d57916SPaul Mackerras return 0; 94f6d57916SPaul Mackerras while (!req.complete) 95f6d57916SPaul Mackerras cuda_poll(); 96f6d57916SPaul Mackerras if (req.reply_len != 7) 97f6d57916SPaul Mackerras printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n", 98f6d57916SPaul Mackerras req.reply_len); 99f6d57916SPaul Mackerras now = (req.reply[3] << 24) + (req.reply[4] << 16) 100f6d57916SPaul Mackerras + (req.reply[5] << 8) + req.reply[6]; 101f6d57916SPaul Mackerras return now - RTC_OFFSET; 102f6d57916SPaul Mackerras #endif /* CONFIG_ADB_CUDA */ 103f6d57916SPaul Mackerras #ifdef CONFIG_ADB_PMU 104f6d57916SPaul Mackerras case SYS_CTRLER_PMU: 105f6d57916SPaul Mackerras if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0) 106f6d57916SPaul Mackerras return 0; 107f6d57916SPaul Mackerras while (!req.complete) 108f6d57916SPaul Mackerras pmu_poll(); 109f6d57916SPaul Mackerras if (req.reply_len != 4) 110f6d57916SPaul Mackerras printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n", 111f6d57916SPaul Mackerras req.reply_len); 112f6d57916SPaul Mackerras now = (req.reply[0] << 24) + (req.reply[1] << 16) 113f6d57916SPaul Mackerras + (req.reply[2] << 8) + req.reply[3]; 114f6d57916SPaul Mackerras return now - RTC_OFFSET; 115f6d57916SPaul Mackerras #endif /* CONFIG_ADB_PMU */ 116f6d57916SPaul Mackerras default: ; 117f6d57916SPaul Mackerras } 118f6d57916SPaul Mackerras return 0; 119f6d57916SPaul Mackerras } 120f6d57916SPaul Mackerras 121f6d57916SPaul Mackerras int 122f6d57916SPaul Mackerras pmac_set_rtc_time(unsigned long nowtime) 123f6d57916SPaul Mackerras { 124f6d57916SPaul Mackerras #if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) 125f6d57916SPaul Mackerras struct adb_request req; 126f6d57916SPaul Mackerras #endif 127f6d57916SPaul Mackerras 128f6d57916SPaul Mackerras nowtime += RTC_OFFSET; 129f6d57916SPaul Mackerras 130f6d57916SPaul Mackerras switch (sys_ctrler) { 131f6d57916SPaul Mackerras #ifdef CONFIG_ADB_CUDA 132f6d57916SPaul Mackerras case SYS_CTRLER_CUDA: 133f6d57916SPaul Mackerras if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME, 134f6d57916SPaul Mackerras nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0) 135f6d57916SPaul Mackerras return 0; 136f6d57916SPaul Mackerras while (!req.complete) 137f6d57916SPaul Mackerras cuda_poll(); 138f6d57916SPaul Mackerras if ((req.reply_len != 3) && (req.reply_len != 7)) 139f6d57916SPaul Mackerras printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n", 140f6d57916SPaul Mackerras req.reply_len); 141f6d57916SPaul Mackerras return 1; 142f6d57916SPaul Mackerras #endif /* CONFIG_ADB_CUDA */ 143f6d57916SPaul Mackerras #ifdef CONFIG_ADB_PMU 144f6d57916SPaul Mackerras case SYS_CTRLER_PMU: 145f6d57916SPaul Mackerras if (pmu_request(&req, NULL, 5, PMU_SET_RTC, 146f6d57916SPaul Mackerras nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0) 147f6d57916SPaul Mackerras return 0; 148f6d57916SPaul Mackerras while (!req.complete) 149f6d57916SPaul Mackerras pmu_poll(); 150f6d57916SPaul Mackerras if (req.reply_len != 0) 151f6d57916SPaul Mackerras printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n", 152f6d57916SPaul Mackerras req.reply_len); 153f6d57916SPaul Mackerras return 1; 154f6d57916SPaul Mackerras #endif /* CONFIG_ADB_PMU */ 155f6d57916SPaul Mackerras default: 156f6d57916SPaul Mackerras return 0; 157f6d57916SPaul Mackerras } 158f6d57916SPaul Mackerras } 159f6d57916SPaul Mackerras 160f6d57916SPaul Mackerras /* 161f6d57916SPaul Mackerras * Calibrate the decrementer register using VIA timer 1. 162f6d57916SPaul Mackerras * This is used both on powermacs and CHRP machines. 163f6d57916SPaul Mackerras */ 164f6d57916SPaul Mackerras int __init 165f6d57916SPaul Mackerras via_calibrate_decr(void) 166f6d57916SPaul Mackerras { 167f6d57916SPaul Mackerras struct device_node *vias; 168f6d57916SPaul Mackerras volatile unsigned char __iomem *via; 169f6d57916SPaul Mackerras int count = VIA_TIMER_FREQ_6 / 100; 170f6d57916SPaul Mackerras unsigned int dstart, dend; 171f6d57916SPaul Mackerras 172f6d57916SPaul Mackerras vias = find_devices("via-cuda"); 173f6d57916SPaul Mackerras if (vias == 0) 174f6d57916SPaul Mackerras vias = find_devices("via-pmu"); 175f6d57916SPaul Mackerras if (vias == 0) 176f6d57916SPaul Mackerras vias = find_devices("via"); 177f6d57916SPaul Mackerras if (vias == 0 || vias->n_addrs == 0) 178f6d57916SPaul Mackerras return 0; 179f6d57916SPaul Mackerras via = ioremap(vias->addrs[0].address, vias->addrs[0].size); 180f6d57916SPaul Mackerras 181f6d57916SPaul Mackerras /* set timer 1 for continuous interrupts */ 182f6d57916SPaul Mackerras out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT); 183f6d57916SPaul Mackerras /* set the counter to a small value */ 184f6d57916SPaul Mackerras out_8(&via[T1CH], 2); 185f6d57916SPaul Mackerras /* set the latch to `count' */ 186f6d57916SPaul Mackerras out_8(&via[T1LL], count); 187f6d57916SPaul Mackerras out_8(&via[T1LH], count >> 8); 188f6d57916SPaul Mackerras /* wait until it hits 0 */ 189f6d57916SPaul Mackerras while ((in_8(&via[IFR]) & T1_INT) == 0) 190f6d57916SPaul Mackerras ; 191f6d57916SPaul Mackerras dstart = get_dec(); 192f6d57916SPaul Mackerras /* clear the interrupt & wait until it hits 0 again */ 193f6d57916SPaul Mackerras in_8(&via[T1CL]); 194f6d57916SPaul Mackerras while ((in_8(&via[IFR]) & T1_INT) == 0) 195f6d57916SPaul Mackerras ; 196f6d57916SPaul Mackerras dend = get_dec(); 197f6d57916SPaul Mackerras 1985629d41dSPaul Mackerras tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100); 199f6d57916SPaul Mackerras tb_to_us = mulhwu_scale_factor(dstart - dend, 60000); 200f6d57916SPaul Mackerras 201f6d57916SPaul Mackerras printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n", 202f6d57916SPaul Mackerras tb_ticks_per_jiffy, dstart - dend); 203f6d57916SPaul Mackerras 204f6d57916SPaul Mackerras iounmap(via); 205f6d57916SPaul Mackerras 206f6d57916SPaul Mackerras return 1; 207f6d57916SPaul Mackerras } 208f6d57916SPaul Mackerras 209f6d57916SPaul Mackerras #ifdef CONFIG_PM 210f6d57916SPaul Mackerras /* 211f6d57916SPaul Mackerras * Reset the time after a sleep. 212f6d57916SPaul Mackerras */ 213f6d57916SPaul Mackerras static int 214f6d57916SPaul Mackerras time_sleep_notify(struct pmu_sleep_notifier *self, int when) 215f6d57916SPaul Mackerras { 216f6d57916SPaul Mackerras static unsigned long time_diff; 217f6d57916SPaul Mackerras unsigned long flags; 218f6d57916SPaul Mackerras unsigned long seq; 219f6d57916SPaul Mackerras 220f6d57916SPaul Mackerras switch (when) { 221f6d57916SPaul Mackerras case PBOOK_SLEEP_NOW: 222f6d57916SPaul Mackerras do { 223f6d57916SPaul Mackerras seq = read_seqbegin_irqsave(&xtime_lock, flags); 224f6d57916SPaul Mackerras time_diff = xtime.tv_sec - pmac_get_rtc_time(); 225f6d57916SPaul Mackerras } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); 226f6d57916SPaul Mackerras break; 227f6d57916SPaul Mackerras case PBOOK_WAKE: 228f6d57916SPaul Mackerras write_seqlock_irqsave(&xtime_lock, flags); 229f6d57916SPaul Mackerras xtime.tv_sec = pmac_get_rtc_time() + time_diff; 230f6d57916SPaul Mackerras xtime.tv_nsec = 0; 231f6d57916SPaul Mackerras last_rtc_update = xtime.tv_sec; 232f6d57916SPaul Mackerras write_sequnlock_irqrestore(&xtime_lock, flags); 233f6d57916SPaul Mackerras break; 234f6d57916SPaul Mackerras } 235f6d57916SPaul Mackerras return PBOOK_SLEEP_OK; 236f6d57916SPaul Mackerras } 237f6d57916SPaul Mackerras 238f6d57916SPaul Mackerras static struct pmu_sleep_notifier time_sleep_notifier = { 239f6d57916SPaul Mackerras time_sleep_notify, SLEEP_LEVEL_MISC, 240f6d57916SPaul Mackerras }; 241f6d57916SPaul Mackerras #endif /* CONFIG_PM */ 242f6d57916SPaul Mackerras 243f6d57916SPaul Mackerras /* 244f6d57916SPaul Mackerras * Query the OF and get the decr frequency. 245f6d57916SPaul Mackerras * This was taken from the pmac time_init() when merging the prep/pmac 246f6d57916SPaul Mackerras * time functions. 247f6d57916SPaul Mackerras */ 248f6d57916SPaul Mackerras void __init 249f6d57916SPaul Mackerras pmac_calibrate_decr(void) 250f6d57916SPaul Mackerras { 251f6d57916SPaul Mackerras struct device_node *cpu; 252f6d57916SPaul Mackerras unsigned int freq, *fp; 253f6d57916SPaul Mackerras 254f6d57916SPaul Mackerras #ifdef CONFIG_PM 255f6d57916SPaul Mackerras pmu_register_sleep_notifier(&time_sleep_notifier); 256f6d57916SPaul Mackerras #endif /* CONFIG_PM */ 257f6d57916SPaul Mackerras 258f6d57916SPaul Mackerras /* We assume MacRISC2 machines have correct device-tree 259f6d57916SPaul Mackerras * calibration. That's better since the VIA itself seems 260f6d57916SPaul Mackerras * to be slightly off. --BenH 261f6d57916SPaul Mackerras */ 262f6d57916SPaul Mackerras if (!machine_is_compatible("MacRISC2") && 263f6d57916SPaul Mackerras !machine_is_compatible("MacRISC3") && 264f6d57916SPaul Mackerras !machine_is_compatible("MacRISC4")) 265f6d57916SPaul Mackerras if (via_calibrate_decr()) 266f6d57916SPaul Mackerras return; 267f6d57916SPaul Mackerras 268f6d57916SPaul Mackerras /* Special case: QuickSilver G4s seem to have a badly calibrated 269f6d57916SPaul Mackerras * timebase-frequency in OF, VIA is much better on these. We should 270f6d57916SPaul Mackerras * probably implement calibration based on the KL timer on these 271f6d57916SPaul Mackerras * machines anyway... -BenH 272f6d57916SPaul Mackerras */ 273f6d57916SPaul Mackerras if (machine_is_compatible("PowerMac3,5")) 274f6d57916SPaul Mackerras if (via_calibrate_decr()) 275f6d57916SPaul Mackerras return; 276f6d57916SPaul Mackerras /* 277f6d57916SPaul Mackerras * The cpu node should have a timebase-frequency property 278f6d57916SPaul Mackerras * to tell us the rate at which the decrementer counts. 279f6d57916SPaul Mackerras */ 280f6d57916SPaul Mackerras cpu = find_type_devices("cpu"); 281f6d57916SPaul Mackerras if (cpu == 0) 282f6d57916SPaul Mackerras panic("can't find cpu node in time_init"); 283f6d57916SPaul Mackerras fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL); 284f6d57916SPaul Mackerras if (fp == 0) 285f6d57916SPaul Mackerras panic("can't get cpu timebase frequency"); 286f6d57916SPaul Mackerras freq = *fp; 287f6d57916SPaul Mackerras printk("time_init: decrementer frequency = %u.%.6u MHz\n", 288f6d57916SPaul Mackerras freq/1000000, freq%1000000); 289f6d57916SPaul Mackerras tb_ticks_per_jiffy = freq / HZ; 290f6d57916SPaul Mackerras tb_to_us = mulhwu_scale_factor(freq, 1000000); 291f6d57916SPaul Mackerras } 292