1 /* 2 * Real Time Clock interface for Linux on Atmel AT91RM9200 3 * 4 * Copyright (C) 2002 Rick Bronson 5 * 6 * Converted to RTC class model by Andrew Victor 7 * 8 * Ported to Linux 2.6 by Steven Scholz 9 * Based on s3c2410-rtc.c Simtec Electronics 10 * 11 * Based on sa1100-rtc.c by Nils Faerber 12 * Based on rtc.c by Paul Gortmaker 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 * 19 */ 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/platform_device.h> 24 #include <linux/time.h> 25 #include <linux/rtc.h> 26 #include <linux/bcd.h> 27 #include <linux/interrupt.h> 28 #include <linux/spinlock.h> 29 #include <linux/ioctl.h> 30 #include <linux/completion.h> 31 #include <linux/io.h> 32 #include <linux/of.h> 33 #include <linux/of_device.h> 34 #include <linux/uaccess.h> 35 36 #include "rtc-at91rm9200.h" 37 38 #define at91_rtc_read(field) \ 39 __raw_readl(at91_rtc_regs + field) 40 #define at91_rtc_write(field, val) \ 41 __raw_writel((val), at91_rtc_regs + field) 42 43 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ 44 45 struct at91_rtc_config { 46 bool use_shadow_imr; 47 }; 48 49 static const struct at91_rtc_config *at91_rtc_config; 50 static DECLARE_COMPLETION(at91_rtc_updated); 51 static DECLARE_COMPLETION(at91_rtc_upd_rdy); 52 static unsigned int at91_alarm_year = AT91_RTC_EPOCH; 53 static void __iomem *at91_rtc_regs; 54 static int irq; 55 static DEFINE_SPINLOCK(at91_rtc_lock); 56 static u32 at91_rtc_shadow_imr; 57 58 static void at91_rtc_write_ier(u32 mask) 59 { 60 unsigned long flags; 61 62 spin_lock_irqsave(&at91_rtc_lock, flags); 63 at91_rtc_shadow_imr |= mask; 64 at91_rtc_write(AT91_RTC_IER, mask); 65 spin_unlock_irqrestore(&at91_rtc_lock, flags); 66 } 67 68 static void at91_rtc_write_idr(u32 mask) 69 { 70 unsigned long flags; 71 72 spin_lock_irqsave(&at91_rtc_lock, flags); 73 at91_rtc_write(AT91_RTC_IDR, mask); 74 /* 75 * Register read back (of any RTC-register) needed to make sure 76 * IDR-register write has reached the peripheral before updating 77 * shadow mask. 78 * 79 * Note that there is still a possibility that the mask is updated 80 * before interrupts have actually been disabled in hardware. The only 81 * way to be certain would be to poll the IMR-register, which is is 82 * the very register we are trying to emulate. The register read back 83 * is a reasonable heuristic. 84 */ 85 at91_rtc_read(AT91_RTC_SR); 86 at91_rtc_shadow_imr &= ~mask; 87 spin_unlock_irqrestore(&at91_rtc_lock, flags); 88 } 89 90 static u32 at91_rtc_read_imr(void) 91 { 92 unsigned long flags; 93 u32 mask; 94 95 if (at91_rtc_config->use_shadow_imr) { 96 spin_lock_irqsave(&at91_rtc_lock, flags); 97 mask = at91_rtc_shadow_imr; 98 spin_unlock_irqrestore(&at91_rtc_lock, flags); 99 } else { 100 mask = at91_rtc_read(AT91_RTC_IMR); 101 } 102 103 return mask; 104 } 105 106 /* 107 * Decode time/date into rtc_time structure 108 */ 109 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 110 struct rtc_time *tm) 111 { 112 unsigned int time, date; 113 114 /* must read twice in case it changes */ 115 do { 116 time = at91_rtc_read(timereg); 117 date = at91_rtc_read(calreg); 118 } while ((time != at91_rtc_read(timereg)) || 119 (date != at91_rtc_read(calreg))); 120 121 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); 122 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); 123 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); 124 125 /* 126 * The Calendar Alarm register does not have a field for 127 * the year - so these will return an invalid value. When an 128 * alarm is set, at91_alarm_year will store the current year. 129 */ 130 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ 131 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ 132 133 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 134 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; 135 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); 136 } 137 138 /* 139 * Read current time and date in RTC 140 */ 141 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 142 { 143 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 144 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 145 tm->tm_year = tm->tm_year - 1900; 146 147 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 148 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 149 tm->tm_hour, tm->tm_min, tm->tm_sec); 150 151 return 0; 152 } 153 154 /* 155 * Set current time and date in RTC 156 */ 157 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 158 { 159 unsigned long cr; 160 161 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 162 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 163 tm->tm_hour, tm->tm_min, tm->tm_sec); 164 165 wait_for_completion(&at91_rtc_upd_rdy); 166 167 /* Stop Time/Calendar from counting */ 168 cr = at91_rtc_read(AT91_RTC_CR); 169 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 170 171 at91_rtc_write_ier(AT91_RTC_ACKUPD); 172 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 173 at91_rtc_write_idr(AT91_RTC_ACKUPD); 174 175 at91_rtc_write(AT91_RTC_TIMR, 176 bin2bcd(tm->tm_sec) << 0 177 | bin2bcd(tm->tm_min) << 8 178 | bin2bcd(tm->tm_hour) << 16); 179 180 at91_rtc_write(AT91_RTC_CALR, 181 bin2bcd((tm->tm_year + 1900) / 100) /* century */ 182 | bin2bcd(tm->tm_year % 100) << 8 /* year */ 183 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 184 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 185 | bin2bcd(tm->tm_mday) << 24); 186 187 /* Restart Time/Calendar */ 188 cr = at91_rtc_read(AT91_RTC_CR); 189 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV); 190 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 191 at91_rtc_write_ier(AT91_RTC_SECEV); 192 193 return 0; 194 } 195 196 /* 197 * Read alarm time and date in RTC 198 */ 199 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 200 { 201 struct rtc_time *tm = &alrm->time; 202 203 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 204 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 205 tm->tm_year = at91_alarm_year - 1900; 206 207 alrm->enabled = (at91_rtc_read_imr() & AT91_RTC_ALARM) 208 ? 1 : 0; 209 210 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 211 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 212 tm->tm_hour, tm->tm_min, tm->tm_sec); 213 214 return 0; 215 } 216 217 /* 218 * Set alarm time and date in RTC 219 */ 220 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 221 { 222 struct rtc_time tm; 223 224 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 225 226 at91_alarm_year = tm.tm_year; 227 228 tm.tm_mon = alrm->time.tm_mon; 229 tm.tm_mday = alrm->time.tm_mday; 230 tm.tm_hour = alrm->time.tm_hour; 231 tm.tm_min = alrm->time.tm_min; 232 tm.tm_sec = alrm->time.tm_sec; 233 234 at91_rtc_write_idr(AT91_RTC_ALARM); 235 at91_rtc_write(AT91_RTC_TIMALR, 236 bin2bcd(tm.tm_sec) << 0 237 | bin2bcd(tm.tm_min) << 8 238 | bin2bcd(tm.tm_hour) << 16 239 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 240 at91_rtc_write(AT91_RTC_CALALR, 241 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 242 | bin2bcd(tm.tm_mday) << 24 243 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 244 245 if (alrm->enabled) { 246 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 247 at91_rtc_write_ier(AT91_RTC_ALARM); 248 } 249 250 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 251 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 252 tm.tm_min, tm.tm_sec); 253 254 return 0; 255 } 256 257 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 258 { 259 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled); 260 261 if (enabled) { 262 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 263 at91_rtc_write_ier(AT91_RTC_ALARM); 264 } else 265 at91_rtc_write_idr(AT91_RTC_ALARM); 266 267 return 0; 268 } 269 /* 270 * Provide additional RTC information in /proc/driver/rtc 271 */ 272 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 273 { 274 unsigned long imr = at91_rtc_read_imr(); 275 276 seq_printf(seq, "update_IRQ\t: %s\n", 277 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 278 seq_printf(seq, "periodic_IRQ\t: %s\n", 279 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 280 281 return 0; 282 } 283 284 /* 285 * IRQ handler for the RTC 286 */ 287 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 288 { 289 struct platform_device *pdev = dev_id; 290 struct rtc_device *rtc = platform_get_drvdata(pdev); 291 unsigned int rtsr; 292 unsigned long events = 0; 293 294 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr(); 295 if (rtsr) { /* this interrupt is shared! Is it ours? */ 296 if (rtsr & AT91_RTC_ALARM) 297 events |= (RTC_AF | RTC_IRQF); 298 if (rtsr & AT91_RTC_SECEV) { 299 complete(&at91_rtc_upd_rdy); 300 at91_rtc_write_idr(AT91_RTC_SECEV); 301 } 302 if (rtsr & AT91_RTC_ACKUPD) 303 complete(&at91_rtc_updated); 304 305 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 306 307 rtc_update_irq(rtc, 1, events); 308 309 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__, 310 events >> 8, events & 0x000000FF); 311 312 return IRQ_HANDLED; 313 } 314 return IRQ_NONE; /* not handled */ 315 } 316 317 static const struct at91_rtc_config at91rm9200_config = { 318 }; 319 320 static const struct at91_rtc_config at91sam9x5_config = { 321 .use_shadow_imr = true, 322 }; 323 324 #ifdef CONFIG_OF 325 static const struct of_device_id at91_rtc_dt_ids[] = { 326 { 327 .compatible = "atmel,at91rm9200-rtc", 328 .data = &at91rm9200_config, 329 }, { 330 .compatible = "atmel,at91sam9x5-rtc", 331 .data = &at91sam9x5_config, 332 }, { 333 /* sentinel */ 334 } 335 }; 336 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids); 337 #endif 338 339 static const struct at91_rtc_config * 340 at91_rtc_get_config(struct platform_device *pdev) 341 { 342 const struct of_device_id *match; 343 344 if (pdev->dev.of_node) { 345 match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node); 346 if (!match) 347 return NULL; 348 return (const struct at91_rtc_config *)match->data; 349 } 350 351 return &at91rm9200_config; 352 } 353 354 static const struct rtc_class_ops at91_rtc_ops = { 355 .read_time = at91_rtc_readtime, 356 .set_time = at91_rtc_settime, 357 .read_alarm = at91_rtc_readalarm, 358 .set_alarm = at91_rtc_setalarm, 359 .proc = at91_rtc_proc, 360 .alarm_irq_enable = at91_rtc_alarm_irq_enable, 361 }; 362 363 /* 364 * Initialize and install RTC driver 365 */ 366 static int __init at91_rtc_probe(struct platform_device *pdev) 367 { 368 struct rtc_device *rtc; 369 struct resource *regs; 370 int ret = 0; 371 372 at91_rtc_config = at91_rtc_get_config(pdev); 373 if (!at91_rtc_config) 374 return -ENODEV; 375 376 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 377 if (!regs) { 378 dev_err(&pdev->dev, "no mmio resource defined\n"); 379 return -ENXIO; 380 } 381 382 irq = platform_get_irq(pdev, 0); 383 if (irq < 0) { 384 dev_err(&pdev->dev, "no irq resource defined\n"); 385 return -ENXIO; 386 } 387 388 at91_rtc_regs = devm_ioremap(&pdev->dev, regs->start, 389 resource_size(regs)); 390 if (!at91_rtc_regs) { 391 dev_err(&pdev->dev, "failed to map registers, aborting.\n"); 392 return -ENOMEM; 393 } 394 395 at91_rtc_write(AT91_RTC_CR, 0); 396 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ 397 398 /* Disable all interrupts */ 399 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM | 400 AT91_RTC_SECEV | AT91_RTC_TIMEV | 401 AT91_RTC_CALEV); 402 403 ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt, 404 IRQF_SHARED, 405 "at91_rtc", pdev); 406 if (ret) { 407 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq); 408 return ret; 409 } 410 411 /* cpu init code should really have flagged this device as 412 * being wake-capable; if it didn't, do that here. 413 */ 414 if (!device_can_wakeup(&pdev->dev)) 415 device_init_wakeup(&pdev->dev, 1); 416 417 rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 418 &at91_rtc_ops, THIS_MODULE); 419 if (IS_ERR(rtc)) 420 return PTR_ERR(rtc); 421 platform_set_drvdata(pdev, rtc); 422 423 /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy 424 * completion. 425 */ 426 at91_rtc_write_ier(AT91_RTC_SECEV); 427 428 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); 429 return 0; 430 } 431 432 /* 433 * Disable and remove the RTC driver 434 */ 435 static int __exit at91_rtc_remove(struct platform_device *pdev) 436 { 437 /* Disable all interrupts */ 438 at91_rtc_write_idr(AT91_RTC_ACKUPD | AT91_RTC_ALARM | 439 AT91_RTC_SECEV | AT91_RTC_TIMEV | 440 AT91_RTC_CALEV); 441 442 return 0; 443 } 444 445 static void at91_rtc_shutdown(struct platform_device *pdev) 446 { 447 /* Disable all interrupts */ 448 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 449 AT91_RTC_SECEV | AT91_RTC_TIMEV | 450 AT91_RTC_CALEV); 451 } 452 453 #ifdef CONFIG_PM_SLEEP 454 455 /* AT91RM9200 RTC Power management control */ 456 457 static u32 at91_rtc_imr; 458 459 static int at91_rtc_suspend(struct device *dev) 460 { 461 /* this IRQ is shared with DBGU and other hardware which isn't 462 * necessarily doing PM like we are... 463 */ 464 at91_rtc_imr = at91_rtc_read_imr() 465 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 466 if (at91_rtc_imr) { 467 if (device_may_wakeup(dev)) 468 enable_irq_wake(irq); 469 else 470 at91_rtc_write_idr(at91_rtc_imr); 471 } 472 return 0; 473 } 474 475 static int at91_rtc_resume(struct device *dev) 476 { 477 if (at91_rtc_imr) { 478 if (device_may_wakeup(dev)) 479 disable_irq_wake(irq); 480 else 481 at91_rtc_write_ier(at91_rtc_imr); 482 } 483 return 0; 484 } 485 #endif 486 487 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume); 488 489 static struct platform_driver at91_rtc_driver = { 490 .remove = __exit_p(at91_rtc_remove), 491 .shutdown = at91_rtc_shutdown, 492 .driver = { 493 .name = "at91_rtc", 494 .pm = &at91_rtc_pm_ops, 495 .of_match_table = of_match_ptr(at91_rtc_dt_ids), 496 }, 497 }; 498 499 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe); 500 501 MODULE_AUTHOR("Rick Bronson"); 502 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 503 MODULE_LICENSE("GPL"); 504 MODULE_ALIAS("platform:at91_rtc"); 505