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/ioctl.h> 29 #include <linux/completion.h> 30 31 #include <asm/uaccess.h> 32 #include <asm/rtc.h> 33 34 #include <asm/mach/time.h> 35 36 #include <asm/arch/at91_rtc.h> 37 38 39 #define AT91_RTC_FREQ 1 40 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ 41 42 static DECLARE_COMPLETION(at91_rtc_updated); 43 static unsigned int at91_alarm_year = AT91_RTC_EPOCH; 44 45 /* 46 * Decode time/date into rtc_time structure 47 */ 48 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 49 struct rtc_time *tm) 50 { 51 unsigned int time, date; 52 53 /* must read twice in case it changes */ 54 do { 55 time = at91_sys_read(timereg); 56 date = at91_sys_read(calreg); 57 } while ((time != at91_sys_read(timereg)) || 58 (date != at91_sys_read(calreg))); 59 60 tm->tm_sec = BCD2BIN((time & AT91_RTC_SEC) >> 0); 61 tm->tm_min = BCD2BIN((time & AT91_RTC_MIN) >> 8); 62 tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16); 63 64 /* 65 * The Calendar Alarm register does not have a field for 66 * the year - so these will return an invalid value. When an 67 * alarm is set, at91_alarm_year wille store the current year. 68 */ 69 tm->tm_year = BCD2BIN(date & AT91_RTC_CENT) * 100; /* century */ 70 tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8); /* year */ 71 72 tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 73 tm->tm_mon = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1; 74 tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24); 75 } 76 77 /* 78 * Read current time and date in RTC 79 */ 80 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 81 { 82 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 83 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 84 tm->tm_year = tm->tm_year - 1900; 85 86 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 87 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 88 tm->tm_hour, tm->tm_min, tm->tm_sec); 89 90 return 0; 91 } 92 93 /* 94 * Set current time and date in RTC 95 */ 96 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 97 { 98 unsigned long cr; 99 100 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 101 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 102 tm->tm_hour, tm->tm_min, tm->tm_sec); 103 104 /* Stop Time/Calendar from counting */ 105 cr = at91_sys_read(AT91_RTC_CR); 106 at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 107 108 at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD); 109 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 110 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); 111 112 at91_sys_write(AT91_RTC_TIMR, 113 BIN2BCD(tm->tm_sec) << 0 114 | BIN2BCD(tm->tm_min) << 8 115 | BIN2BCD(tm->tm_hour) << 16); 116 117 at91_sys_write(AT91_RTC_CALR, 118 BIN2BCD((tm->tm_year + 1900) / 100) /* century */ 119 | BIN2BCD(tm->tm_year % 100) << 8 /* year */ 120 | BIN2BCD(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 121 | BIN2BCD(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 122 | BIN2BCD(tm->tm_mday) << 24); 123 124 /* Restart Time/Calendar */ 125 cr = at91_sys_read(AT91_RTC_CR); 126 at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 127 128 return 0; 129 } 130 131 /* 132 * Read alarm time and date in RTC 133 */ 134 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 135 { 136 struct rtc_time *tm = &alrm->time; 137 138 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 139 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 140 tm->tm_year = at91_alarm_year - 1900; 141 142 alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM) 143 ? 1 : 0; 144 145 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 146 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 147 tm->tm_hour, tm->tm_min, tm->tm_sec); 148 149 return 0; 150 } 151 152 /* 153 * Set alarm time and date in RTC 154 */ 155 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 156 { 157 struct rtc_time tm; 158 159 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 160 161 at91_alarm_year = tm.tm_year; 162 163 tm.tm_hour = alrm->time.tm_hour; 164 tm.tm_min = alrm->time.tm_min; 165 tm.tm_sec = alrm->time.tm_sec; 166 167 at91_sys_write(AT91_RTC_TIMALR, 168 BIN2BCD(tm.tm_sec) << 0 169 | BIN2BCD(tm.tm_min) << 8 170 | BIN2BCD(tm.tm_hour) << 16 171 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 172 at91_sys_write(AT91_RTC_CALALR, 173 BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 174 | BIN2BCD(tm.tm_mday) << 24 175 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 176 177 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 178 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 179 tm.tm_min, tm.tm_sec); 180 181 return 0; 182 } 183 184 /* 185 * Handle commands from user-space 186 */ 187 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd, 188 unsigned long arg) 189 { 190 int ret = 0; 191 192 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg); 193 194 switch (cmd) { 195 case RTC_AIE_OFF: /* alarm off */ 196 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM); 197 break; 198 case RTC_AIE_ON: /* alarm on */ 199 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); 200 break; 201 case RTC_UIE_OFF: /* update off */ 202 case RTC_PIE_OFF: /* periodic off */ 203 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV); 204 break; 205 case RTC_UIE_ON: /* update on */ 206 case RTC_PIE_ON: /* periodic on */ 207 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV); 208 break; 209 case RTC_IRQP_READ: /* read periodic alarm frequency */ 210 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg); 211 break; 212 case RTC_IRQP_SET: /* set periodic alarm frequency */ 213 if (arg != AT91_RTC_FREQ) 214 ret = -EINVAL; 215 break; 216 default: 217 ret = -ENOIOCTLCMD; 218 break; 219 } 220 221 return ret; 222 } 223 224 /* 225 * Provide additional RTC information in /proc/driver/rtc 226 */ 227 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 228 { 229 unsigned long imr = at91_sys_read(AT91_RTC_IMR); 230 231 seq_printf(seq, "update_IRQ\t: %s\n", 232 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 233 seq_printf(seq, "periodic_IRQ\t: %s\n", 234 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 235 seq_printf(seq, "periodic_freq\t: %ld\n", 236 (unsigned long) AT91_RTC_FREQ); 237 238 return 0; 239 } 240 241 /* 242 * IRQ handler for the RTC 243 */ 244 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 245 { 246 struct platform_device *pdev = dev_id; 247 struct rtc_device *rtc = platform_get_drvdata(pdev); 248 unsigned int rtsr; 249 unsigned long events = 0; 250 251 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR); 252 if (rtsr) { /* this interrupt is shared! Is it ours? */ 253 if (rtsr & AT91_RTC_ALARM) 254 events |= (RTC_AF | RTC_IRQF); 255 if (rtsr & AT91_RTC_SECEV) 256 events |= (RTC_UF | RTC_IRQF); 257 if (rtsr & AT91_RTC_ACKUPD) 258 complete(&at91_rtc_updated); 259 260 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 261 262 rtc_update_irq(&rtc->class_dev, 1, events); 263 264 pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__, 265 events >> 8, events & 0x000000FF); 266 267 return IRQ_HANDLED; 268 } 269 return IRQ_NONE; /* not handled */ 270 } 271 272 static const struct rtc_class_ops at91_rtc_ops = { 273 .ioctl = at91_rtc_ioctl, 274 .read_time = at91_rtc_readtime, 275 .set_time = at91_rtc_settime, 276 .read_alarm = at91_rtc_readalarm, 277 .set_alarm = at91_rtc_setalarm, 278 .proc = at91_rtc_proc, 279 }; 280 281 /* 282 * Initialize and install RTC driver 283 */ 284 static int __init at91_rtc_probe(struct platform_device *pdev) 285 { 286 struct rtc_device *rtc; 287 int ret; 288 289 at91_sys_write(AT91_RTC_CR, 0); 290 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */ 291 292 /* Disable all interrupts */ 293 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 294 AT91_RTC_SECEV | AT91_RTC_TIMEV | 295 AT91_RTC_CALEV); 296 297 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt, 298 IRQF_DISABLED | IRQF_SHARED, 299 "at91_rtc", pdev); 300 if (ret) { 301 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", 302 AT91_ID_SYS); 303 return ret; 304 } 305 306 rtc = rtc_device_register(pdev->name, &pdev->dev, 307 &at91_rtc_ops, THIS_MODULE); 308 if (IS_ERR(rtc)) { 309 free_irq(AT91_ID_SYS, pdev); 310 return PTR_ERR(rtc); 311 } 312 platform_set_drvdata(pdev, rtc); 313 device_init_wakeup(&pdev->dev, 1); 314 315 printk(KERN_INFO "AT91 Real Time Clock driver.\n"); 316 return 0; 317 } 318 319 /* 320 * Disable and remove the RTC driver 321 */ 322 static int __devexit at91_rtc_remove(struct platform_device *pdev) 323 { 324 struct rtc_device *rtc = platform_get_drvdata(pdev); 325 326 /* Disable all interrupts */ 327 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 328 AT91_RTC_SECEV | AT91_RTC_TIMEV | 329 AT91_RTC_CALEV); 330 free_irq(AT91_ID_SYS, pdev); 331 332 rtc_device_unregister(rtc); 333 platform_set_drvdata(pdev, NULL); 334 device_init_wakeup(&pdev->dev, 0); 335 336 return 0; 337 } 338 339 #ifdef CONFIG_PM 340 341 /* AT91RM9200 RTC Power management control */ 342 343 static struct timespec at91_rtc_delta; 344 static u32 at91_rtc_imr; 345 346 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state) 347 { 348 struct rtc_time tm; 349 struct timespec time; 350 351 time.tv_nsec = 0; 352 353 /* calculate time delta for suspend */ 354 at91_rtc_readtime(&pdev->dev, &tm); 355 rtc_tm_to_time(&tm, &time.tv_sec); 356 save_time_delta(&at91_rtc_delta, &time); 357 358 /* this IRQ is shared with DBGU and other hardware which isn't 359 * necessarily doing PM like we are... 360 */ 361 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR) 362 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 363 if (at91_rtc_imr) { 364 if (device_may_wakeup(&pdev->dev)) 365 enable_irq_wake(AT91_ID_SYS); 366 else 367 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr); 368 } 369 370 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 371 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday, 372 tm.tm_hour, tm.tm_min, tm.tm_sec); 373 374 return 0; 375 } 376 377 static int at91_rtc_resume(struct platform_device *pdev) 378 { 379 struct rtc_time tm; 380 struct timespec time; 381 382 time.tv_nsec = 0; 383 384 at91_rtc_readtime(&pdev->dev, &tm); 385 rtc_tm_to_time(&tm, &time.tv_sec); 386 restore_time_delta(&at91_rtc_delta, &time); 387 388 if (at91_rtc_imr) { 389 if (device_may_wakeup(&pdev->dev)) 390 disable_irq_wake(AT91_ID_SYS); 391 else 392 at91_sys_write(AT91_RTC_IER, at91_rtc_imr); 393 } 394 395 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 396 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday, 397 tm.tm_hour, tm.tm_min, tm.tm_sec); 398 399 return 0; 400 } 401 #else 402 #define at91_rtc_suspend NULL 403 #define at91_rtc_resume NULL 404 #endif 405 406 static struct platform_driver at91_rtc_driver = { 407 .probe = at91_rtc_probe, 408 .remove = at91_rtc_remove, 409 .suspend = at91_rtc_suspend, 410 .resume = at91_rtc_resume, 411 .driver = { 412 .name = "at91_rtc", 413 .owner = THIS_MODULE, 414 }, 415 }; 416 417 static int __init at91_rtc_init(void) 418 { 419 return platform_driver_register(&at91_rtc_driver); 420 } 421 422 static void __exit at91_rtc_exit(void) 423 { 424 platform_driver_unregister(&at91_rtc_driver); 425 } 426 427 module_init(at91_rtc_init); 428 module_exit(at91_rtc_exit); 429 430 MODULE_AUTHOR("Rick Bronson"); 431 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 432 MODULE_LICENSE("GPL"); 433