1/* 2 * Support for periodic interrupts (100 per second) and for getting 3 * the current time from the RTC on Power Macintoshes. 4 * 5 * We use the decrementer register for our periodic interrupts. 6 * 7 * Paul Mackerras August 1996. 8 * Copyright (C) 1996 Paul Mackerras. 9 * Copyright (C) 2003-2005 Benjamin Herrenschmidt. 10 * 11 */ 12#include <linux/errno.h> 13#include <linux/sched.h> 14#include <linux/kernel.h> 15#include <linux/param.h> 16#include <linux/string.h> 17#include <linux/mm.h> 18#include <linux/init.h> 19#include <linux/time.h> 20#include <linux/adb.h> 21#include <linux/cuda.h> 22#include <linux/pmu.h> 23#include <linux/interrupt.h> 24#include <linux/hardirq.h> 25#include <linux/rtc.h> 26 27#include <asm/sections.h> 28#include <asm/prom.h> 29#include <asm/system.h> 30#include <asm/io.h> 31#include <asm/pgtable.h> 32#include <asm/machdep.h> 33#include <asm/time.h> 34#include <asm/nvram.h> 35#include <asm/smu.h> 36 37#undef DEBUG 38 39#ifdef DEBUG 40#define DBG(x...) printk(x) 41#else 42#define DBG(x...) 43#endif 44 45/* Apparently the RTC stores seconds since 1 Jan 1904 */ 46#define RTC_OFFSET 2082844800 47 48/* 49 * Calibrate the decrementer frequency with the VIA timer 1. 50 */ 51#define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */ 52 53/* VIA registers */ 54#define RS 0x200 /* skip between registers */ 55#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 56#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 57#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 58#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 59#define ACR (11*RS) /* Auxiliary control register */ 60#define IFR (13*RS) /* Interrupt flag register */ 61 62/* Bits in ACR */ 63#define T1MODE 0xc0 /* Timer 1 mode */ 64#define T1MODE_CONT 0x40 /* continuous interrupts */ 65 66/* Bits in IFR and IER */ 67#define T1_INT 0x40 /* Timer 1 interrupt */ 68 69long __init pmac_time_init(void) 70{ 71 s32 delta = 0; 72#ifdef CONFIG_NVRAM 73 int dst; 74 75 delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16; 76 delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8; 77 delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb); 78 if (delta & 0x00800000UL) 79 delta |= 0xFF000000UL; 80 dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0); 81 printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60, 82 dst ? "on" : "off"); 83#endif 84 return delta; 85} 86 87#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) 88static void to_rtc_time(unsigned long now, struct rtc_time *tm) 89{ 90 to_tm(now, tm); 91 tm->tm_year -= 1900; 92 tm->tm_mon -= 1; 93} 94#endif 95 96#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) || defined(CONFIG_PMAC_SMU) 97static unsigned long from_rtc_time(struct rtc_time *tm) 98{ 99 return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday, 100 tm->tm_hour, tm->tm_min, tm->tm_sec); 101} 102#endif 103 104#ifdef CONFIG_ADB_CUDA 105static unsigned long cuda_get_time(void) 106{ 107 struct adb_request req; 108 unsigned int now; 109 110 if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0) 111 return 0; 112 while (!req.complete) 113 cuda_poll(); 114 if (req.reply_len != 7) 115 printk(KERN_ERR "cuda_get_time: got %d byte reply\n", 116 req.reply_len); 117 now = (req.reply[3] << 24) + (req.reply[4] << 16) 118 + (req.reply[5] << 8) + req.reply[6]; 119 return ((unsigned long)now) - RTC_OFFSET; 120} 121 122#define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm)) 123 124static int cuda_set_rtc_time(struct rtc_time *tm) 125{ 126 unsigned int nowtime; 127 struct adb_request req; 128 129 nowtime = from_rtc_time(tm) + RTC_OFFSET; 130 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME, 131 nowtime >> 24, nowtime >> 16, nowtime >> 8, 132 nowtime) < 0) 133 return -ENXIO; 134 while (!req.complete) 135 cuda_poll(); 136 if ((req.reply_len != 3) && (req.reply_len != 7)) 137 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n", 138 req.reply_len); 139 return 0; 140} 141 142#else 143#define cuda_get_time() 0 144#define cuda_get_rtc_time(tm) 145#define cuda_set_rtc_time(tm) 0 146#endif 147 148#ifdef CONFIG_ADB_PMU 149static unsigned long pmu_get_time(void) 150{ 151 struct adb_request req; 152 unsigned int now; 153 154 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0) 155 return 0; 156 pmu_wait_complete(&req); 157 if (req.reply_len != 4) 158 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n", 159 req.reply_len); 160 now = (req.reply[0] << 24) + (req.reply[1] << 16) 161 + (req.reply[2] << 8) + req.reply[3]; 162 return ((unsigned long)now) - RTC_OFFSET; 163} 164 165#define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm)) 166 167static int pmu_set_rtc_time(struct rtc_time *tm) 168{ 169 unsigned int nowtime; 170 struct adb_request req; 171 172 nowtime = from_rtc_time(tm) + RTC_OFFSET; 173 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24, 174 nowtime >> 16, nowtime >> 8, nowtime) < 0) 175 return -ENXIO; 176 pmu_wait_complete(&req); 177 if (req.reply_len != 0) 178 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n", 179 req.reply_len); 180 return 0; 181} 182 183#else 184#define pmu_get_time() 0 185#define pmu_get_rtc_time(tm) 186#define pmu_set_rtc_time(tm) 0 187#endif 188 189#ifdef CONFIG_PMAC_SMU 190static unsigned long smu_get_time(void) 191{ 192 struct rtc_time tm; 193 194 if (smu_get_rtc_time(&tm, 1)) 195 return 0; 196 return from_rtc_time(&tm); 197} 198 199#else 200#define smu_get_time() 0 201#define smu_get_rtc_time(tm, spin) 202#define smu_set_rtc_time(tm, spin) 0 203#endif 204 205/* Can't be __init, it's called when suspending and resuming */ 206unsigned long pmac_get_boot_time(void) 207{ 208 /* Get the time from the RTC, used only at boot time */ 209 switch (sys_ctrler) { 210 case SYS_CTRLER_CUDA: 211 return cuda_get_time(); 212 case SYS_CTRLER_PMU: 213 return pmu_get_time(); 214 case SYS_CTRLER_SMU: 215 return smu_get_time(); 216 default: 217 return 0; 218 } 219} 220 221void pmac_get_rtc_time(struct rtc_time *tm) 222{ 223 /* Get the time from the RTC, used only at boot time */ 224 switch (sys_ctrler) { 225 case SYS_CTRLER_CUDA: 226 cuda_get_rtc_time(tm); 227 break; 228 case SYS_CTRLER_PMU: 229 pmu_get_rtc_time(tm); 230 break; 231 case SYS_CTRLER_SMU: 232 smu_get_rtc_time(tm, 1); 233 break; 234 default: 235 ; 236 } 237} 238 239int pmac_set_rtc_time(struct rtc_time *tm) 240{ 241 switch (sys_ctrler) { 242 case SYS_CTRLER_CUDA: 243 return cuda_set_rtc_time(tm); 244 case SYS_CTRLER_PMU: 245 return pmu_set_rtc_time(tm); 246 case SYS_CTRLER_SMU: 247 return smu_set_rtc_time(tm, 1); 248 default: 249 return -ENODEV; 250 } 251} 252 253#ifdef CONFIG_PPC32 254/* 255 * Calibrate the decrementer register using VIA timer 1. 256 * This is used both on powermacs and CHRP machines. 257 */ 258int __init via_calibrate_decr(void) 259{ 260 struct device_node *vias; 261 volatile unsigned char __iomem *via; 262 int count = VIA_TIMER_FREQ_6 / 100; 263 unsigned int dstart, dend; 264 struct resource rsrc; 265 266 vias = of_find_node_by_name(NULL, "via-cuda"); 267 if (vias == NULL) 268 vias = of_find_node_by_name(NULL, "via-pmu"); 269 if (vias == NULL) 270 vias = of_find_node_by_name(NULL, "via"); 271 if (vias == NULL || of_address_to_resource(vias, 0, &rsrc)) { 272 of_node_put(vias); 273 return 0; 274 } 275 of_node_put(vias); 276 via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1); 277 if (via == NULL) { 278 printk(KERN_ERR "Failed to map VIA for timer calibration !\n"); 279 return 0; 280 } 281 282 /* set timer 1 for continuous interrupts */ 283 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT); 284 /* set the counter to a small value */ 285 out_8(&via[T1CH], 2); 286 /* set the latch to `count' */ 287 out_8(&via[T1LL], count); 288 out_8(&via[T1LH], count >> 8); 289 /* wait until it hits 0 */ 290 while ((in_8(&via[IFR]) & T1_INT) == 0) 291 ; 292 dstart = get_dec(); 293 /* clear the interrupt & wait until it hits 0 again */ 294 in_8(&via[T1CL]); 295 while ((in_8(&via[IFR]) & T1_INT) == 0) 296 ; 297 dend = get_dec(); 298 299 ppc_tb_freq = (dstart - dend) * 100 / 6; 300 301 iounmap(via); 302 303 return 1; 304} 305#endif 306 307/* 308 * Query the OF and get the decr frequency. 309 */ 310void __init pmac_calibrate_decr(void) 311{ 312 generic_calibrate_decr(); 313 314#ifdef CONFIG_PPC32 315 /* We assume MacRISC2 machines have correct device-tree 316 * calibration. That's better since the VIA itself seems 317 * to be slightly off. --BenH 318 */ 319 if (!of_machine_is_compatible("MacRISC2") && 320 !of_machine_is_compatible("MacRISC3") && 321 !of_machine_is_compatible("MacRISC4")) 322 if (via_calibrate_decr()) 323 return; 324 325 /* Special case: QuickSilver G4s seem to have a badly calibrated 326 * timebase-frequency in OF, VIA is much better on these. We should 327 * probably implement calibration based on the KL timer on these 328 * machines anyway... -BenH 329 */ 330 if (of_machine_is_compatible("PowerMac3,5")) 331 if (via_calibrate_decr()) 332 return; 333#endif 334} 335