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 33 #include <mach/at91_rtc.h> 34 35 36 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ 37 38 static DECLARE_COMPLETION(at91_rtc_updated); 39 static unsigned int at91_alarm_year = AT91_RTC_EPOCH; 40 41 /* 42 * Decode time/date into rtc_time structure 43 */ 44 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 45 struct rtc_time *tm) 46 { 47 unsigned int time, date; 48 49 /* must read twice in case it changes */ 50 do { 51 time = at91_sys_read(timereg); 52 date = at91_sys_read(calreg); 53 } while ((time != at91_sys_read(timereg)) || 54 (date != at91_sys_read(calreg))); 55 56 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); 57 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); 58 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); 59 60 /* 61 * The Calendar Alarm register does not have a field for 62 * the year - so these will return an invalid value. When an 63 * alarm is set, at91_alarm_year wille store the current year. 64 */ 65 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ 66 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ 67 68 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 69 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; 70 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); 71 } 72 73 /* 74 * Read current time and date in RTC 75 */ 76 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 77 { 78 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 79 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 80 tm->tm_year = tm->tm_year - 1900; 81 82 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 83 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 84 tm->tm_hour, tm->tm_min, tm->tm_sec); 85 86 return 0; 87 } 88 89 /* 90 * Set current time and date in RTC 91 */ 92 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 93 { 94 unsigned long cr; 95 96 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 97 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 98 tm->tm_hour, tm->tm_min, tm->tm_sec); 99 100 /* Stop Time/Calendar from counting */ 101 cr = at91_sys_read(AT91_RTC_CR); 102 at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 103 104 at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD); 105 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 106 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); 107 108 at91_sys_write(AT91_RTC_TIMR, 109 bin2bcd(tm->tm_sec) << 0 110 | bin2bcd(tm->tm_min) << 8 111 | bin2bcd(tm->tm_hour) << 16); 112 113 at91_sys_write(AT91_RTC_CALR, 114 bin2bcd((tm->tm_year + 1900) / 100) /* century */ 115 | bin2bcd(tm->tm_year % 100) << 8 /* year */ 116 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 117 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 118 | bin2bcd(tm->tm_mday) << 24); 119 120 /* Restart Time/Calendar */ 121 cr = at91_sys_read(AT91_RTC_CR); 122 at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 123 124 return 0; 125 } 126 127 /* 128 * Read alarm time and date in RTC 129 */ 130 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 131 { 132 struct rtc_time *tm = &alrm->time; 133 134 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 135 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 136 tm->tm_year = at91_alarm_year - 1900; 137 138 alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM) 139 ? 1 : 0; 140 141 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 142 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 143 tm->tm_hour, tm->tm_min, tm->tm_sec); 144 145 return 0; 146 } 147 148 /* 149 * Set alarm time and date in RTC 150 */ 151 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 152 { 153 struct rtc_time tm; 154 155 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 156 157 at91_alarm_year = tm.tm_year; 158 159 tm.tm_hour = alrm->time.tm_hour; 160 tm.tm_min = alrm->time.tm_min; 161 tm.tm_sec = alrm->time.tm_sec; 162 163 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM); 164 at91_sys_write(AT91_RTC_TIMALR, 165 bin2bcd(tm.tm_sec) << 0 166 | bin2bcd(tm.tm_min) << 8 167 | bin2bcd(tm.tm_hour) << 16 168 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 169 at91_sys_write(AT91_RTC_CALALR, 170 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 171 | bin2bcd(tm.tm_mday) << 24 172 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 173 174 if (alrm->enabled) { 175 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 176 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); 177 } 178 179 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 180 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 181 tm.tm_min, tm.tm_sec); 182 183 return 0; 184 } 185 186 /* 187 * Handle commands from user-space 188 */ 189 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd, 190 unsigned long arg) 191 { 192 int ret = 0; 193 194 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg); 195 196 /* important: scrub old status before enabling IRQs */ 197 switch (cmd) { 198 case RTC_UIE_OFF: /* update off */ 199 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV); 200 break; 201 case RTC_UIE_ON: /* update on */ 202 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV); 203 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV); 204 break; 205 default: 206 ret = -ENOIOCTLCMD; 207 break; 208 } 209 210 return ret; 211 } 212 213 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 214 { 215 pr_debug("%s(): cmd=%08x\n", __func__, enabled); 216 217 if (enabled) { 218 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 219 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); 220 } else 221 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM); 222 223 return 0; 224 } 225 /* 226 * Provide additional RTC information in /proc/driver/rtc 227 */ 228 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 229 { 230 unsigned long imr = at91_sys_read(AT91_RTC_IMR); 231 232 seq_printf(seq, "update_IRQ\t: %s\n", 233 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 234 seq_printf(seq, "periodic_IRQ\t: %s\n", 235 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 236 237 return 0; 238 } 239 240 /* 241 * IRQ handler for the RTC 242 */ 243 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 244 { 245 struct platform_device *pdev = dev_id; 246 struct rtc_device *rtc = platform_get_drvdata(pdev); 247 unsigned int rtsr; 248 unsigned long events = 0; 249 250 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR); 251 if (rtsr) { /* this interrupt is shared! Is it ours? */ 252 if (rtsr & AT91_RTC_ALARM) 253 events |= (RTC_AF | RTC_IRQF); 254 if (rtsr & AT91_RTC_SECEV) 255 events |= (RTC_UF | RTC_IRQF); 256 if (rtsr & AT91_RTC_ACKUPD) 257 complete(&at91_rtc_updated); 258 259 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 260 261 rtc_update_irq(rtc, 1, events); 262 263 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__, 264 events >> 8, events & 0x000000FF); 265 266 return IRQ_HANDLED; 267 } 268 return IRQ_NONE; /* not handled */ 269 } 270 271 static const struct rtc_class_ops at91_rtc_ops = { 272 .ioctl = at91_rtc_ioctl, 273 .read_time = at91_rtc_readtime, 274 .set_time = at91_rtc_settime, 275 .read_alarm = at91_rtc_readalarm, 276 .set_alarm = at91_rtc_setalarm, 277 .proc = at91_rtc_proc, 278 .alarm_irq_enable = at91_rtc_alarm_irq_enable, 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_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 /* cpu init code should really have flagged this device as 307 * being wake-capable; if it didn't, do that here. 308 */ 309 if (!device_can_wakeup(&pdev->dev)) 310 device_init_wakeup(&pdev->dev, 1); 311 312 rtc = rtc_device_register(pdev->name, &pdev->dev, 313 &at91_rtc_ops, THIS_MODULE); 314 if (IS_ERR(rtc)) { 315 free_irq(AT91_ID_SYS, pdev); 316 return PTR_ERR(rtc); 317 } 318 platform_set_drvdata(pdev, rtc); 319 320 printk(KERN_INFO "AT91 Real Time Clock driver.\n"); 321 return 0; 322 } 323 324 /* 325 * Disable and remove the RTC driver 326 */ 327 static int __exit at91_rtc_remove(struct platform_device *pdev) 328 { 329 struct rtc_device *rtc = platform_get_drvdata(pdev); 330 331 /* Disable all interrupts */ 332 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 333 AT91_RTC_SECEV | AT91_RTC_TIMEV | 334 AT91_RTC_CALEV); 335 free_irq(AT91_ID_SYS, pdev); 336 337 rtc_device_unregister(rtc); 338 platform_set_drvdata(pdev, NULL); 339 340 return 0; 341 } 342 343 #ifdef CONFIG_PM 344 345 /* AT91RM9200 RTC Power management control */ 346 347 static u32 at91_rtc_imr; 348 349 static int at91_rtc_suspend(struct device *dev) 350 { 351 /* this IRQ is shared with DBGU and other hardware which isn't 352 * necessarily doing PM like we are... 353 */ 354 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR) 355 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 356 if (at91_rtc_imr) { 357 if (device_may_wakeup(dev)) 358 enable_irq_wake(AT91_ID_SYS); 359 else 360 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr); 361 } 362 return 0; 363 } 364 365 static int at91_rtc_resume(struct device *dev) 366 { 367 if (at91_rtc_imr) { 368 if (device_may_wakeup(dev)) 369 disable_irq_wake(AT91_ID_SYS); 370 else 371 at91_sys_write(AT91_RTC_IER, at91_rtc_imr); 372 } 373 return 0; 374 } 375 376 static const struct dev_pm_ops at91_rtc_pm = { 377 .suspend = at91_rtc_suspend, 378 .resume = at91_rtc_resume, 379 }; 380 381 #define at91_rtc_pm_ptr &at91_rtc_pm 382 383 #else 384 #define at91_rtc_pm_ptr NULL 385 #endif 386 387 static struct platform_driver at91_rtc_driver = { 388 .remove = __exit_p(at91_rtc_remove), 389 .driver = { 390 .name = "at91_rtc", 391 .owner = THIS_MODULE, 392 .pm = at91_rtc_pm_ptr, 393 }, 394 }; 395 396 static int __init at91_rtc_init(void) 397 { 398 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe); 399 } 400 401 static void __exit at91_rtc_exit(void) 402 { 403 platform_driver_unregister(&at91_rtc_driver); 404 } 405 406 module_init(at91_rtc_init); 407 module_exit(at91_rtc_exit); 408 409 MODULE_AUTHOR("Rick Bronson"); 410 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 411 MODULE_LICENSE("GPL"); 412 MODULE_ALIAS("platform:at91_rtc"); 413