1 /* 2 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx 3 * 4 * Copyright (c) 2000 Nils Faerber 5 * 6 * Based on rtc.c by Paul Gortmaker 7 * 8 * Original Driver by Nils Faerber <nils@kernelconcepts.de> 9 * 10 * Modifications from: 11 * CIH <cih@coventive.com> 12 * Nicolas Pitre <nico@fluxnic.net> 13 * Andrew Christian <andrew.christian@hp.com> 14 * 15 * Converted to the RTC subsystem and Driver Model 16 * by Richard Purdie <rpurdie@rpsys.net> 17 * 18 * This program is free software; you can redistribute it and/or 19 * modify it under the terms of the GNU General Public License 20 * as published by the Free Software Foundation; either version 21 * 2 of the License, or (at your option) any later version. 22 */ 23 24 #include <linux/platform_device.h> 25 #include <linux/module.h> 26 #include <linux/rtc.h> 27 #include <linux/init.h> 28 #include <linux/fs.h> 29 #include <linux/interrupt.h> 30 #include <linux/string.h> 31 #include <linux/pm.h> 32 #include <linux/bitops.h> 33 34 #include <mach/hardware.h> 35 #include <asm/irq.h> 36 37 #ifdef CONFIG_ARCH_PXA 38 #include <mach/regs-rtc.h> 39 #include <mach/regs-ost.h> 40 #endif 41 42 #define RTC_DEF_DIVIDER 32768 - 1 43 #define RTC_DEF_TRIM 0 44 45 static unsigned long rtc_freq = 1024; 46 static unsigned long timer_freq; 47 static struct rtc_time rtc_alarm; 48 static DEFINE_SPINLOCK(sa1100_rtc_lock); 49 50 static inline int rtc_periodic_alarm(struct rtc_time *tm) 51 { 52 return (tm->tm_year == -1) || 53 ((unsigned)tm->tm_mon >= 12) || 54 ((unsigned)(tm->tm_mday - 1) >= 31) || 55 ((unsigned)tm->tm_hour > 23) || 56 ((unsigned)tm->tm_min > 59) || 57 ((unsigned)tm->tm_sec > 59); 58 } 59 60 /* 61 * Calculate the next alarm time given the requested alarm time mask 62 * and the current time. 63 */ 64 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm) 65 { 66 unsigned long next_time; 67 unsigned long now_time; 68 69 next->tm_year = now->tm_year; 70 next->tm_mon = now->tm_mon; 71 next->tm_mday = now->tm_mday; 72 next->tm_hour = alrm->tm_hour; 73 next->tm_min = alrm->tm_min; 74 next->tm_sec = alrm->tm_sec; 75 76 rtc_tm_to_time(now, &now_time); 77 rtc_tm_to_time(next, &next_time); 78 79 if (next_time < now_time) { 80 /* Advance one day */ 81 next_time += 60 * 60 * 24; 82 rtc_time_to_tm(next_time, next); 83 } 84 } 85 86 static int rtc_update_alarm(struct rtc_time *alrm) 87 { 88 struct rtc_time alarm_tm, now_tm; 89 unsigned long now, time; 90 int ret; 91 92 do { 93 now = RCNR; 94 rtc_time_to_tm(now, &now_tm); 95 rtc_next_alarm_time(&alarm_tm, &now_tm, alrm); 96 ret = rtc_tm_to_time(&alarm_tm, &time); 97 if (ret != 0) 98 break; 99 100 RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL); 101 RTAR = time; 102 } while (now != RCNR); 103 104 return ret; 105 } 106 107 static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id) 108 { 109 struct platform_device *pdev = to_platform_device(dev_id); 110 struct rtc_device *rtc = platform_get_drvdata(pdev); 111 unsigned int rtsr; 112 unsigned long events = 0; 113 114 spin_lock(&sa1100_rtc_lock); 115 116 rtsr = RTSR; 117 /* clear interrupt sources */ 118 RTSR = 0; 119 RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2); 120 121 /* clear alarm interrupt if it has occurred */ 122 if (rtsr & RTSR_AL) 123 rtsr &= ~RTSR_ALE; 124 RTSR = rtsr & (RTSR_ALE | RTSR_HZE); 125 126 /* update irq data & counter */ 127 if (rtsr & RTSR_AL) 128 events |= RTC_AF | RTC_IRQF; 129 if (rtsr & RTSR_HZ) 130 events |= RTC_UF | RTC_IRQF; 131 132 rtc_update_irq(rtc, 1, events); 133 134 if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm)) 135 rtc_update_alarm(&rtc_alarm); 136 137 spin_unlock(&sa1100_rtc_lock); 138 139 return IRQ_HANDLED; 140 } 141 142 static int rtc_timer1_count; 143 144 static irqreturn_t timer1_interrupt(int irq, void *dev_id) 145 { 146 struct platform_device *pdev = to_platform_device(dev_id); 147 struct rtc_device *rtc = platform_get_drvdata(pdev); 148 149 /* 150 * If we match for the first time, rtc_timer1_count will be 1. 151 * Otherwise, we wrapped around (very unlikely but 152 * still possible) so compute the amount of missed periods. 153 * The match reg is updated only when the data is actually retrieved 154 * to avoid unnecessary interrupts. 155 */ 156 OSSR = OSSR_M1; /* clear match on timer1 */ 157 158 rtc_update_irq(rtc, rtc_timer1_count, RTC_PF | RTC_IRQF); 159 160 if (rtc_timer1_count == 1) 161 rtc_timer1_count = (rtc_freq * ((1 << 30) / (timer_freq >> 2))); 162 163 return IRQ_HANDLED; 164 } 165 166 static int sa1100_rtc_read_callback(struct device *dev, int data) 167 { 168 if (data & RTC_PF) { 169 /* interpolate missed periods and set match for the next */ 170 unsigned long period = timer_freq / rtc_freq; 171 unsigned long oscr = OSCR; 172 unsigned long osmr1 = OSMR1; 173 unsigned long missed = (oscr - osmr1)/period; 174 data += missed << 8; 175 OSSR = OSSR_M1; /* clear match on timer 1 */ 176 OSMR1 = osmr1 + (missed + 1)*period; 177 /* Ensure we didn't miss another match in the mean time. 178 * Here we compare (match - OSCR) 8 instead of 0 -- 179 * see comment in pxa_timer_interrupt() for explanation. 180 */ 181 while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) { 182 data += 0x100; 183 OSSR = OSSR_M1; /* clear match on timer 1 */ 184 OSMR1 = osmr1 + period; 185 } 186 } 187 return data; 188 } 189 190 static int sa1100_rtc_open(struct device *dev) 191 { 192 int ret; 193 194 ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED, 195 "rtc 1Hz", dev); 196 if (ret) { 197 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTC1Hz); 198 goto fail_ui; 199 } 200 ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, IRQF_DISABLED, 201 "rtc Alrm", dev); 202 if (ret) { 203 dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm); 204 goto fail_ai; 205 } 206 ret = request_irq(IRQ_OST1, timer1_interrupt, IRQF_DISABLED, 207 "rtc timer", dev); 208 if (ret) { 209 dev_err(dev, "IRQ %d already in use.\n", IRQ_OST1); 210 goto fail_pi; 211 } 212 return 0; 213 214 fail_pi: 215 free_irq(IRQ_RTCAlrm, dev); 216 fail_ai: 217 free_irq(IRQ_RTC1Hz, dev); 218 fail_ui: 219 return ret; 220 } 221 222 static void sa1100_rtc_release(struct device *dev) 223 { 224 spin_lock_irq(&sa1100_rtc_lock); 225 RTSR = 0; 226 OIER &= ~OIER_E1; 227 OSSR = OSSR_M1; 228 spin_unlock_irq(&sa1100_rtc_lock); 229 230 free_irq(IRQ_OST1, dev); 231 free_irq(IRQ_RTCAlrm, dev); 232 free_irq(IRQ_RTC1Hz, dev); 233 } 234 235 236 static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd, 237 unsigned long arg) 238 { 239 switch(cmd) { 240 case RTC_AIE_OFF: 241 spin_lock_irq(&sa1100_rtc_lock); 242 RTSR &= ~RTSR_ALE; 243 spin_unlock_irq(&sa1100_rtc_lock); 244 return 0; 245 case RTC_AIE_ON: 246 spin_lock_irq(&sa1100_rtc_lock); 247 RTSR |= RTSR_ALE; 248 spin_unlock_irq(&sa1100_rtc_lock); 249 return 0; 250 case RTC_UIE_OFF: 251 spin_lock_irq(&sa1100_rtc_lock); 252 RTSR &= ~RTSR_HZE; 253 spin_unlock_irq(&sa1100_rtc_lock); 254 return 0; 255 case RTC_UIE_ON: 256 spin_lock_irq(&sa1100_rtc_lock); 257 RTSR |= RTSR_HZE; 258 spin_unlock_irq(&sa1100_rtc_lock); 259 return 0; 260 case RTC_PIE_OFF: 261 spin_lock_irq(&sa1100_rtc_lock); 262 OIER &= ~OIER_E1; 263 spin_unlock_irq(&sa1100_rtc_lock); 264 return 0; 265 case RTC_PIE_ON: 266 spin_lock_irq(&sa1100_rtc_lock); 267 OSMR1 = timer_freq / rtc_freq + OSCR; 268 OIER |= OIER_E1; 269 rtc_timer1_count = 1; 270 spin_unlock_irq(&sa1100_rtc_lock); 271 return 0; 272 case RTC_IRQP_READ: 273 return put_user(rtc_freq, (unsigned long *)arg); 274 case RTC_IRQP_SET: 275 if (arg < 1 || arg > timer_freq) 276 return -EINVAL; 277 rtc_freq = arg; 278 return 0; 279 } 280 return -ENOIOCTLCMD; 281 } 282 283 static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm) 284 { 285 rtc_time_to_tm(RCNR, tm); 286 return 0; 287 } 288 289 static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm) 290 { 291 unsigned long time; 292 int ret; 293 294 ret = rtc_tm_to_time(tm, &time); 295 if (ret == 0) 296 RCNR = time; 297 return ret; 298 } 299 300 static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 301 { 302 u32 rtsr; 303 304 memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time)); 305 rtsr = RTSR; 306 alrm->enabled = (rtsr & RTSR_ALE) ? 1 : 0; 307 alrm->pending = (rtsr & RTSR_AL) ? 1 : 0; 308 return 0; 309 } 310 311 static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 312 { 313 int ret; 314 315 spin_lock_irq(&sa1100_rtc_lock); 316 ret = rtc_update_alarm(&alrm->time); 317 if (ret == 0) { 318 if (alrm->enabled) 319 RTSR |= RTSR_ALE; 320 else 321 RTSR &= ~RTSR_ALE; 322 } 323 spin_unlock_irq(&sa1100_rtc_lock); 324 325 return ret; 326 } 327 328 static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq) 329 { 330 seq_printf(seq, "trim/divider\t: 0x%08x\n", (u32) RTTR); 331 seq_printf(seq, "update_IRQ\t: %s\n", 332 (RTSR & RTSR_HZE) ? "yes" : "no"); 333 seq_printf(seq, "periodic_IRQ\t: %s\n", 334 (OIER & OIER_E1) ? "yes" : "no"); 335 seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq); 336 337 return 0; 338 } 339 340 static const struct rtc_class_ops sa1100_rtc_ops = { 341 .open = sa1100_rtc_open, 342 .read_callback = sa1100_rtc_read_callback, 343 .release = sa1100_rtc_release, 344 .ioctl = sa1100_rtc_ioctl, 345 .read_time = sa1100_rtc_read_time, 346 .set_time = sa1100_rtc_set_time, 347 .read_alarm = sa1100_rtc_read_alarm, 348 .set_alarm = sa1100_rtc_set_alarm, 349 .proc = sa1100_rtc_proc, 350 }; 351 352 static int sa1100_rtc_probe(struct platform_device *pdev) 353 { 354 struct rtc_device *rtc; 355 356 timer_freq = get_clock_tick_rate(); 357 358 /* 359 * According to the manual we should be able to let RTTR be zero 360 * and then a default diviser for a 32.768KHz clock is used. 361 * Apparently this doesn't work, at least for my SA1110 rev 5. 362 * If the clock divider is uninitialized then reset it to the 363 * default value to get the 1Hz clock. 364 */ 365 if (RTTR == 0) { 366 RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16); 367 dev_warn(&pdev->dev, "warning: initializing default clock divider/trim value\n"); 368 /* The current RTC value probably doesn't make sense either */ 369 RCNR = 0; 370 } 371 372 device_init_wakeup(&pdev->dev, 1); 373 374 rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops, 375 THIS_MODULE); 376 377 if (IS_ERR(rtc)) 378 return PTR_ERR(rtc); 379 380 platform_set_drvdata(pdev, rtc); 381 382 return 0; 383 } 384 385 static int sa1100_rtc_remove(struct platform_device *pdev) 386 { 387 struct rtc_device *rtc = platform_get_drvdata(pdev); 388 389 if (rtc) 390 rtc_device_unregister(rtc); 391 392 return 0; 393 } 394 395 #ifdef CONFIG_PM 396 static int sa1100_rtc_suspend(struct device *dev) 397 { 398 if (device_may_wakeup(dev)) 399 enable_irq_wake(IRQ_RTCAlrm); 400 return 0; 401 } 402 403 static int sa1100_rtc_resume(struct device *dev) 404 { 405 if (device_may_wakeup(dev)) 406 disable_irq_wake(IRQ_RTCAlrm); 407 return 0; 408 } 409 410 static const struct dev_pm_ops sa1100_rtc_pm_ops = { 411 .suspend = sa1100_rtc_suspend, 412 .resume = sa1100_rtc_resume, 413 }; 414 #endif 415 416 static struct platform_driver sa1100_rtc_driver = { 417 .probe = sa1100_rtc_probe, 418 .remove = sa1100_rtc_remove, 419 .driver = { 420 .name = "sa1100-rtc", 421 #ifdef CONFIG_PM 422 .pm = &sa1100_rtc_pm_ops, 423 #endif 424 }, 425 }; 426 427 static int __init sa1100_rtc_init(void) 428 { 429 return platform_driver_register(&sa1100_rtc_driver); 430 } 431 432 static void __exit sa1100_rtc_exit(void) 433 { 434 platform_driver_unregister(&sa1100_rtc_driver); 435 } 436 437 module_init(sa1100_rtc_init); 438 module_exit(sa1100_rtc_exit); 439 440 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); 441 MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)"); 442 MODULE_LICENSE("GPL"); 443 MODULE_ALIAS("platform:sa1100-rtc"); 444