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 #include <linux/io.h> 31 32 #include <asm/uaccess.h> 33 34 #include "rtc-at91rm9200.h" 35 36 #define at91_rtc_read(field) \ 37 __raw_readl(at91_rtc_regs + field) 38 #define at91_rtc_write(field, val) \ 39 __raw_writel((val), at91_rtc_regs + field) 40 41 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ 42 43 static DECLARE_COMPLETION(at91_rtc_updated); 44 static unsigned int at91_alarm_year = AT91_RTC_EPOCH; 45 static void __iomem *at91_rtc_regs; 46 static int irq; 47 static u32 at91_rtc_imr; 48 49 /* 50 * Decode time/date into rtc_time structure 51 */ 52 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 53 struct rtc_time *tm) 54 { 55 unsigned int time, date; 56 57 /* must read twice in case it changes */ 58 do { 59 time = at91_rtc_read(timereg); 60 date = at91_rtc_read(calreg); 61 } while ((time != at91_rtc_read(timereg)) || 62 (date != at91_rtc_read(calreg))); 63 64 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); 65 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); 66 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); 67 68 /* 69 * The Calendar Alarm register does not have a field for 70 * the year - so these will return an invalid value. When an 71 * alarm is set, at91_alarm_year will store the current year. 72 */ 73 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ 74 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ 75 76 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 77 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; 78 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); 79 } 80 81 /* 82 * Read current time and date in RTC 83 */ 84 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 85 { 86 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 87 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 88 tm->tm_year = tm->tm_year - 1900; 89 90 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 91 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 92 tm->tm_hour, tm->tm_min, tm->tm_sec); 93 94 return 0; 95 } 96 97 /* 98 * Set current time and date in RTC 99 */ 100 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 101 { 102 unsigned long cr; 103 104 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 105 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 106 tm->tm_hour, tm->tm_min, tm->tm_sec); 107 108 /* Stop Time/Calendar from counting */ 109 cr = at91_rtc_read(AT91_RTC_CR); 110 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 111 112 at91_rtc_imr |= AT91_RTC_ACKUPD; 113 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD); 114 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 115 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); 116 at91_rtc_imr &= ~AT91_RTC_ACKUPD; 117 118 at91_rtc_write(AT91_RTC_TIMR, 119 bin2bcd(tm->tm_sec) << 0 120 | bin2bcd(tm->tm_min) << 8 121 | bin2bcd(tm->tm_hour) << 16); 122 123 at91_rtc_write(AT91_RTC_CALR, 124 bin2bcd((tm->tm_year + 1900) / 100) /* century */ 125 | bin2bcd(tm->tm_year % 100) << 8 /* year */ 126 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 127 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 128 | bin2bcd(tm->tm_mday) << 24); 129 130 /* Restart Time/Calendar */ 131 cr = at91_rtc_read(AT91_RTC_CR); 132 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 133 134 return 0; 135 } 136 137 /* 138 * Read alarm time and date in RTC 139 */ 140 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 141 { 142 struct rtc_time *tm = &alrm->time; 143 144 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 145 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 146 tm->tm_year = at91_alarm_year - 1900; 147 148 alrm->enabled = (at91_rtc_imr & AT91_RTC_ALARM) 149 ? 1 : 0; 150 151 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 152 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 153 tm->tm_hour, tm->tm_min, tm->tm_sec); 154 155 return 0; 156 } 157 158 /* 159 * Set alarm time and date in RTC 160 */ 161 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 162 { 163 struct rtc_time tm; 164 165 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 166 167 at91_alarm_year = tm.tm_year; 168 169 tm.tm_hour = alrm->time.tm_hour; 170 tm.tm_min = alrm->time.tm_min; 171 tm.tm_sec = alrm->time.tm_sec; 172 173 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 174 at91_rtc_imr &= ~AT91_RTC_ALARM; 175 at91_rtc_write(AT91_RTC_TIMALR, 176 bin2bcd(tm.tm_sec) << 0 177 | bin2bcd(tm.tm_min) << 8 178 | bin2bcd(tm.tm_hour) << 16 179 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 180 at91_rtc_write(AT91_RTC_CALALR, 181 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 182 | bin2bcd(tm.tm_mday) << 24 183 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 184 185 if (alrm->enabled) { 186 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 187 at91_rtc_imr |= AT91_RTC_ALARM; 188 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 189 } 190 191 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 192 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 193 tm.tm_min, tm.tm_sec); 194 195 return 0; 196 } 197 198 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 199 { 200 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled); 201 202 if (enabled) { 203 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 204 at91_rtc_imr |= AT91_RTC_ALARM; 205 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 206 } else { 207 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 208 at91_rtc_imr &= ~AT91_RTC_ALARM; 209 } 210 211 return 0; 212 } 213 /* 214 * Provide additional RTC information in /proc/driver/rtc 215 */ 216 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 217 { 218 seq_printf(seq, "update_IRQ\t: %s\n", 219 (at91_rtc_imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 220 seq_printf(seq, "periodic_IRQ\t: %s\n", 221 (at91_rtc_imr & AT91_RTC_SECEV) ? "yes" : "no"); 222 223 return 0; 224 } 225 226 /* 227 * IRQ handler for the RTC 228 */ 229 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 230 { 231 struct platform_device *pdev = dev_id; 232 struct rtc_device *rtc = platform_get_drvdata(pdev); 233 unsigned int rtsr; 234 unsigned long events = 0; 235 236 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_imr; 237 if (rtsr) { /* this interrupt is shared! Is it ours? */ 238 if (rtsr & AT91_RTC_ALARM) 239 events |= (RTC_AF | RTC_IRQF); 240 if (rtsr & AT91_RTC_SECEV) 241 events |= (RTC_UF | RTC_IRQF); 242 if (rtsr & AT91_RTC_ACKUPD) 243 complete(&at91_rtc_updated); 244 245 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 246 247 rtc_update_irq(rtc, 1, events); 248 249 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__, 250 events >> 8, events & 0x000000FF); 251 252 return IRQ_HANDLED; 253 } 254 return IRQ_NONE; /* not handled */ 255 } 256 257 static const struct rtc_class_ops at91_rtc_ops = { 258 .read_time = at91_rtc_readtime, 259 .set_time = at91_rtc_settime, 260 .read_alarm = at91_rtc_readalarm, 261 .set_alarm = at91_rtc_setalarm, 262 .proc = at91_rtc_proc, 263 .alarm_irq_enable = at91_rtc_alarm_irq_enable, 264 }; 265 266 /* 267 * Initialize and install RTC driver 268 */ 269 static int __init at91_rtc_probe(struct platform_device *pdev) 270 { 271 struct rtc_device *rtc; 272 struct resource *regs; 273 int ret = 0; 274 275 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 276 if (!regs) { 277 dev_err(&pdev->dev, "no mmio resource defined\n"); 278 return -ENXIO; 279 } 280 281 irq = platform_get_irq(pdev, 0); 282 if (irq < 0) { 283 dev_err(&pdev->dev, "no irq resource defined\n"); 284 return -ENXIO; 285 } 286 287 at91_rtc_regs = ioremap(regs->start, resource_size(regs)); 288 if (!at91_rtc_regs) { 289 dev_err(&pdev->dev, "failed to map registers, aborting.\n"); 290 return -ENOMEM; 291 } 292 293 at91_rtc_write(AT91_RTC_CR, 0); 294 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ 295 296 /* Disable all interrupts */ 297 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 298 AT91_RTC_SECEV | AT91_RTC_TIMEV | 299 AT91_RTC_CALEV); 300 at91_rtc_imr = 0; 301 302 ret = request_irq(irq, at91_rtc_interrupt, 303 IRQF_SHARED, 304 "at91_rtc", pdev); 305 if (ret) { 306 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq); 307 return ret; 308 } 309 310 /* cpu init code should really have flagged this device as 311 * being wake-capable; if it didn't, do that here. 312 */ 313 if (!device_can_wakeup(&pdev->dev)) 314 device_init_wakeup(&pdev->dev, 1); 315 316 rtc = rtc_device_register(pdev->name, &pdev->dev, 317 &at91_rtc_ops, THIS_MODULE); 318 if (IS_ERR(rtc)) { 319 free_irq(irq, pdev); 320 return PTR_ERR(rtc); 321 } 322 platform_set_drvdata(pdev, rtc); 323 324 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); 325 return 0; 326 } 327 328 /* 329 * Disable and remove the RTC driver 330 */ 331 static int __exit at91_rtc_remove(struct platform_device *pdev) 332 { 333 struct rtc_device *rtc = platform_get_drvdata(pdev); 334 335 /* Disable all interrupts */ 336 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 337 AT91_RTC_SECEV | AT91_RTC_TIMEV | 338 AT91_RTC_CALEV); 339 at91_rtc_imr = 0; 340 free_irq(irq, pdev); 341 342 rtc_device_unregister(rtc); 343 platform_set_drvdata(pdev, NULL); 344 345 return 0; 346 } 347 348 #ifdef CONFIG_PM 349 350 /* AT91RM9200 RTC Power management control */ 351 352 static u32 at91_rtc_bkpimr; 353 354 355 static int at91_rtc_suspend(struct device *dev) 356 { 357 /* this IRQ is shared with DBGU and other hardware which isn't 358 * necessarily doing PM like we are... 359 */ 360 at91_rtc_bkpimr = at91_rtc_imr & (AT91_RTC_ALARM|AT91_RTC_SECEV); 361 if (at91_rtc_bkpimr) { 362 if (device_may_wakeup(dev)) { 363 enable_irq_wake(irq); 364 } else { 365 at91_rtc_write(AT91_RTC_IDR, at91_rtc_bkpimr); 366 at91_rtc_imr &= ~at91_rtc_bkpimr; 367 } 368 } 369 return 0; 370 } 371 372 static int at91_rtc_resume(struct device *dev) 373 { 374 if (at91_rtc_bkpimr) { 375 if (device_may_wakeup(dev)) { 376 disable_irq_wake(irq); 377 } else { 378 at91_rtc_imr |= at91_rtc_bkpimr; 379 at91_rtc_write(AT91_RTC_IER, at91_rtc_bkpimr); 380 } 381 } 382 return 0; 383 } 384 385 static const struct dev_pm_ops at91_rtc_pm = { 386 .suspend = at91_rtc_suspend, 387 .resume = at91_rtc_resume, 388 }; 389 390 #define at91_rtc_pm_ptr &at91_rtc_pm 391 392 #else 393 #define at91_rtc_pm_ptr NULL 394 #endif 395 396 static struct platform_driver at91_rtc_driver = { 397 .remove = __exit_p(at91_rtc_remove), 398 .driver = { 399 .name = "at91_rtc", 400 .owner = THIS_MODULE, 401 .pm = at91_rtc_pm_ptr, 402 }, 403 }; 404 405 static int __init at91_rtc_init(void) 406 { 407 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe); 408 } 409 410 static void __exit at91_rtc_exit(void) 411 { 412 platform_driver_unregister(&at91_rtc_driver); 413 } 414 415 module_init(at91_rtc_init); 416 module_exit(at91_rtc_exit); 417 418 MODULE_AUTHOR("Rick Bronson"); 419 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 420 MODULE_LICENSE("GPL"); 421 MODULE_ALIAS("platform:at91_rtc"); 422