1 /* linux/arch/sparc/kernel/time.c 2 * 3 * Copyright (C) 1995 David S. Miller (davem@davemloft.net) 4 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu) 5 * 6 * Chris Davis (cdavis@cois.on.ca) 03/27/1998 7 * Added support for the intersil on the sun4/4200 8 * 9 * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998 10 * Support for MicroSPARC-IIep, PCI CPU. 11 * 12 * This file handles the Sparc specific time handling details. 13 * 14 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 15 * "A Kernel Model for Precision Timekeeping" by Dave Mills 16 */ 17 #include <linux/errno.h> 18 #include <linux/module.h> 19 #include <linux/sched.h> 20 #include <linux/kernel.h> 21 #include <linux/param.h> 22 #include <linux/string.h> 23 #include <linux/mm.h> 24 #include <linux/interrupt.h> 25 #include <linux/time.h> 26 #include <linux/rtc.h> 27 #include <linux/rtc/m48t59.h> 28 #include <linux/timex.h> 29 #include <linux/init.h> 30 #include <linux/pci.h> 31 #include <linux/ioport.h> 32 #include <linux/profile.h> 33 #include <linux/of.h> 34 #include <linux/of_device.h> 35 #include <linux/platform_device.h> 36 37 #include <asm/oplib.h> 38 #include <asm/timer.h> 39 #include <asm/system.h> 40 #include <asm/irq.h> 41 #include <asm/io.h> 42 #include <asm/idprom.h> 43 #include <asm/machines.h> 44 #include <asm/page.h> 45 #include <asm/pcic.h> 46 #include <asm/irq_regs.h> 47 48 #include "irq.h" 49 50 DEFINE_SPINLOCK(rtc_lock); 51 EXPORT_SYMBOL(rtc_lock); 52 53 static int set_rtc_mmss(unsigned long); 54 static int sbus_do_settimeofday(struct timespec *tv); 55 56 unsigned long profile_pc(struct pt_regs *regs) 57 { 58 extern char __copy_user_begin[], __copy_user_end[]; 59 extern char __atomic_begin[], __atomic_end[]; 60 extern char __bzero_begin[], __bzero_end[]; 61 62 unsigned long pc = regs->pc; 63 64 if (in_lock_functions(pc) || 65 (pc >= (unsigned long) __copy_user_begin && 66 pc < (unsigned long) __copy_user_end) || 67 (pc >= (unsigned long) __atomic_begin && 68 pc < (unsigned long) __atomic_end) || 69 (pc >= (unsigned long) __bzero_begin && 70 pc < (unsigned long) __bzero_end)) 71 pc = regs->u_regs[UREG_RETPC]; 72 return pc; 73 } 74 75 EXPORT_SYMBOL(profile_pc); 76 77 __volatile__ unsigned int *master_l10_counter; 78 79 /* 80 * timer_interrupt() needs to keep up the real-time clock, 81 * as well as call the "do_timer()" routine every clocktick 82 */ 83 84 #define TICK_SIZE (tick_nsec / 1000) 85 86 static irqreturn_t timer_interrupt(int dummy, void *dev_id) 87 { 88 /* last time the cmos clock got updated */ 89 static long last_rtc_update; 90 91 #ifndef CONFIG_SMP 92 profile_tick(CPU_PROFILING); 93 #endif 94 95 /* Protect counter clear so that do_gettimeoffset works */ 96 write_seqlock(&xtime_lock); 97 98 clear_clock_irq(); 99 100 do_timer(1); 101 102 /* Determine when to update the Mostek clock. */ 103 if (ntp_synced() && 104 xtime.tv_sec > last_rtc_update + 660 && 105 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && 106 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { 107 if (set_rtc_mmss(xtime.tv_sec) == 0) 108 last_rtc_update = xtime.tv_sec; 109 else 110 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ 111 } 112 write_sequnlock(&xtime_lock); 113 114 #ifndef CONFIG_SMP 115 update_process_times(user_mode(get_irq_regs())); 116 #endif 117 return IRQ_HANDLED; 118 } 119 120 static unsigned char mostek_read_byte(struct device *dev, u32 ofs) 121 { 122 struct platform_device *pdev = to_platform_device(dev); 123 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 124 125 return readb(pdata->ioaddr + ofs); 126 } 127 128 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val) 129 { 130 struct platform_device *pdev = to_platform_device(dev); 131 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 132 133 writeb(val, pdata->ioaddr + ofs); 134 } 135 136 static struct m48t59_plat_data m48t59_data = { 137 .read_byte = mostek_read_byte, 138 .write_byte = mostek_write_byte, 139 }; 140 141 /* resource is set at runtime */ 142 static struct platform_device m48t59_rtc = { 143 .name = "rtc-m48t59", 144 .id = 0, 145 .num_resources = 1, 146 .dev = { 147 .platform_data = &m48t59_data, 148 }, 149 }; 150 151 static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match) 152 { 153 struct device_node *dp = op->node; 154 const char *model = of_get_property(dp, "model", NULL); 155 156 if (!model) 157 return -ENODEV; 158 159 m48t59_rtc.resource = &op->resource[0]; 160 if (!strcmp(model, "mk48t02")) { 161 /* Map the clock register io area read-only */ 162 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0, 163 2048, "rtc-m48t59"); 164 m48t59_data.type = M48T59RTC_TYPE_M48T02; 165 } else if (!strcmp(model, "mk48t08")) { 166 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0, 167 8192, "rtc-m48t59"); 168 m48t59_data.type = M48T59RTC_TYPE_M48T08; 169 } else 170 return -ENODEV; 171 172 if (platform_device_register(&m48t59_rtc) < 0) 173 printk(KERN_ERR "Registering RTC device failed\n"); 174 175 return 0; 176 } 177 178 static struct of_device_id __initdata clock_match[] = { 179 { 180 .name = "eeprom", 181 }, 182 {}, 183 }; 184 185 static struct of_platform_driver clock_driver = { 186 .match_table = clock_match, 187 .probe = clock_probe, 188 .driver = { 189 .name = "rtc", 190 }, 191 }; 192 193 194 /* Probe for the mostek real time clock chip. */ 195 static int __init clock_init(void) 196 { 197 return of_register_driver(&clock_driver, &of_platform_bus_type); 198 } 199 200 /* Must be after subsys_initcall() so that busses are probed. Must 201 * be before device_initcall() because things like the RTC driver 202 * need to see the clock registers. 203 */ 204 fs_initcall(clock_init); 205 206 static void __init sbus_time_init(void) 207 { 208 209 BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM); 210 btfixup(); 211 212 sparc_init_timers(timer_interrupt); 213 214 /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */ 215 local_irq_enable(); 216 } 217 218 void __init time_init(void) 219 { 220 #ifdef CONFIG_PCI 221 extern void pci_time_init(void); 222 if (pcic_present()) { 223 pci_time_init(); 224 return; 225 } 226 #endif 227 sbus_time_init(); 228 } 229 230 static inline unsigned long do_gettimeoffset(void) 231 { 232 unsigned long val = *master_l10_counter; 233 unsigned long usec = (val >> 10) & 0x1fffff; 234 235 /* Limit hit? */ 236 if (val & 0x80000000) 237 usec += 1000000 / HZ; 238 239 return usec; 240 } 241 242 /* Ok, my cute asm atomicity trick doesn't work anymore. 243 * There are just too many variables that need to be protected 244 * now (both members of xtime, et al.) 245 */ 246 void do_gettimeofday(struct timeval *tv) 247 { 248 unsigned long flags; 249 unsigned long seq; 250 unsigned long usec, sec; 251 unsigned long max_ntp_tick = tick_usec - tickadj; 252 253 do { 254 seq = read_seqbegin_irqsave(&xtime_lock, flags); 255 usec = do_gettimeoffset(); 256 257 /* 258 * If time_adjust is negative then NTP is slowing the clock 259 * so make sure not to go into next possible interval. 260 * Better to lose some accuracy than have time go backwards.. 261 */ 262 if (unlikely(time_adjust < 0)) 263 usec = min(usec, max_ntp_tick); 264 265 sec = xtime.tv_sec; 266 usec += (xtime.tv_nsec / 1000); 267 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); 268 269 while (usec >= 1000000) { 270 usec -= 1000000; 271 sec++; 272 } 273 274 tv->tv_sec = sec; 275 tv->tv_usec = usec; 276 } 277 278 EXPORT_SYMBOL(do_gettimeofday); 279 280 int do_settimeofday(struct timespec *tv) 281 { 282 int ret; 283 284 write_seqlock_irq(&xtime_lock); 285 ret = bus_do_settimeofday(tv); 286 write_sequnlock_irq(&xtime_lock); 287 clock_was_set(); 288 return ret; 289 } 290 291 EXPORT_SYMBOL(do_settimeofday); 292 293 static int sbus_do_settimeofday(struct timespec *tv) 294 { 295 time_t wtm_sec, sec = tv->tv_sec; 296 long wtm_nsec, nsec = tv->tv_nsec; 297 298 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) 299 return -EINVAL; 300 301 /* 302 * This is revolting. We need to set "xtime" correctly. However, the 303 * value in this location is the value at the most recent update of 304 * wall time. Discover what correction gettimeofday() would have 305 * made, and then undo it! 306 */ 307 nsec -= 1000 * do_gettimeoffset(); 308 309 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); 310 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); 311 312 set_normalized_timespec(&xtime, sec, nsec); 313 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); 314 315 ntp_clear(); 316 return 0; 317 } 318 319 static int set_rtc_mmss(unsigned long secs) 320 { 321 struct rtc_device *rtc = rtc_class_open("rtc0"); 322 int err = -1; 323 324 if (rtc) { 325 err = rtc_set_mmss(rtc, secs); 326 rtc_class_close(rtc); 327 } 328 329 return err; 330 } 331