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/io.h> 30 #include <asm/pgtable.h> 31 #include <asm/machdep.h> 32 #include <asm/time.h> 33 #include <asm/nvram.h> 34 #include <asm/smu.h> 35 36 #undef DEBUG 37 38 #ifdef DEBUG 39 #define DBG(x...) printk(x) 40 #else 41 #define DBG(x...) 42 #endif 43 44 /* Apparently the RTC stores seconds since 1 Jan 1904 */ 45 #define RTC_OFFSET 2082844800 46 47 /* 48 * Calibrate the decrementer frequency with the VIA timer 1. 49 */ 50 #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */ 51 52 /* VIA registers */ 53 #define RS 0x200 /* skip between registers */ 54 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 55 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 56 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 57 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 58 #define ACR (11*RS) /* Auxiliary control register */ 59 #define IFR (13*RS) /* Interrupt flag register */ 60 61 /* Bits in ACR */ 62 #define T1MODE 0xc0 /* Timer 1 mode */ 63 #define T1MODE_CONT 0x40 /* continuous interrupts */ 64 65 /* Bits in IFR and IER */ 66 #define T1_INT 0x40 /* Timer 1 interrupt */ 67 68 long __init pmac_time_init(void) 69 { 70 s32 delta = 0; 71 #ifdef CONFIG_NVRAM 72 int dst; 73 74 delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16; 75 delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8; 76 delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb); 77 if (delta & 0x00800000UL) 78 delta |= 0xFF000000UL; 79 dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0); 80 printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60, 81 dst ? "on" : "off"); 82 #endif 83 return delta; 84 } 85 86 #if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) 87 static void to_rtc_time(unsigned long now, struct rtc_time *tm) 88 { 89 to_tm(now, tm); 90 tm->tm_year -= 1900; 91 tm->tm_mon -= 1; 92 } 93 #endif 94 95 #if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) || \ 96 defined(CONFIG_PMAC_SMU) 97 static 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 105 static 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)) 123 124 static 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 149 static 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)) 166 167 static 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 190 static 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 */ 206 unsigned 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 } 220 221 void 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 } 238 239 int 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 */ 258 int __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, resource_size(&rsrc)); 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 */ 310 void __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