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_IDR, AT91_RTC_ALARM); 168 at91_sys_write(AT91_RTC_TIMALR, 169 BIN2BCD(tm.tm_sec) << 0 170 | BIN2BCD(tm.tm_min) << 8 171 | BIN2BCD(tm.tm_hour) << 16 172 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 173 at91_sys_write(AT91_RTC_CALALR, 174 BIN2BCD(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 175 | BIN2BCD(tm.tm_mday) << 24 176 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 177 178 if (alrm->enabled) 179 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); 180 181 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__, 182 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 183 tm.tm_min, tm.tm_sec); 184 185 return 0; 186 } 187 188 /* 189 * Handle commands from user-space 190 */ 191 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd, 192 unsigned long arg) 193 { 194 int ret = 0; 195 196 pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg); 197 198 switch (cmd) { 199 case RTC_AIE_OFF: /* alarm off */ 200 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM); 201 break; 202 case RTC_AIE_ON: /* alarm on */ 203 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); 204 break; 205 case RTC_UIE_OFF: /* update off */ 206 case RTC_PIE_OFF: /* periodic off */ 207 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV); 208 break; 209 case RTC_UIE_ON: /* update on */ 210 case RTC_PIE_ON: /* periodic on */ 211 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV); 212 break; 213 case RTC_IRQP_READ: /* read periodic alarm frequency */ 214 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg); 215 break; 216 case RTC_IRQP_SET: /* set periodic alarm frequency */ 217 if (arg != AT91_RTC_FREQ) 218 ret = -EINVAL; 219 break; 220 default: 221 ret = -ENOIOCTLCMD; 222 break; 223 } 224 225 return ret; 226 } 227 228 /* 229 * Provide additional RTC information in /proc/driver/rtc 230 */ 231 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 232 { 233 unsigned long imr = at91_sys_read(AT91_RTC_IMR); 234 235 seq_printf(seq, "update_IRQ\t: %s\n", 236 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 237 seq_printf(seq, "periodic_IRQ\t: %s\n", 238 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 239 seq_printf(seq, "periodic_freq\t: %ld\n", 240 (unsigned long) AT91_RTC_FREQ); 241 242 return 0; 243 } 244 245 /* 246 * IRQ handler for the RTC 247 */ 248 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 249 { 250 struct platform_device *pdev = dev_id; 251 struct rtc_device *rtc = platform_get_drvdata(pdev); 252 unsigned int rtsr; 253 unsigned long events = 0; 254 255 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR); 256 if (rtsr) { /* this interrupt is shared! Is it ours? */ 257 if (rtsr & AT91_RTC_ALARM) 258 events |= (RTC_AF | RTC_IRQF); 259 if (rtsr & AT91_RTC_SECEV) 260 events |= (RTC_UF | RTC_IRQF); 261 if (rtsr & AT91_RTC_ACKUPD) 262 complete(&at91_rtc_updated); 263 264 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 265 266 rtc_update_irq(rtc, 1, events); 267 268 pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__, 269 events >> 8, events & 0x000000FF); 270 271 return IRQ_HANDLED; 272 } 273 return IRQ_NONE; /* not handled */ 274 } 275 276 static const struct rtc_class_ops at91_rtc_ops = { 277 .ioctl = at91_rtc_ioctl, 278 .read_time = at91_rtc_readtime, 279 .set_time = at91_rtc_settime, 280 .read_alarm = at91_rtc_readalarm, 281 .set_alarm = at91_rtc_setalarm, 282 .proc = at91_rtc_proc, 283 }; 284 285 /* 286 * Initialize and install RTC driver 287 */ 288 static int __init at91_rtc_probe(struct platform_device *pdev) 289 { 290 struct rtc_device *rtc; 291 int ret; 292 293 at91_sys_write(AT91_RTC_CR, 0); 294 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */ 295 296 /* Disable all interrupts */ 297 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 298 AT91_RTC_SECEV | AT91_RTC_TIMEV | 299 AT91_RTC_CALEV); 300 301 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt, 302 IRQF_DISABLED | IRQF_SHARED, 303 "at91_rtc", pdev); 304 if (ret) { 305 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", 306 AT91_ID_SYS); 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(AT91_ID_SYS, pdev); 320 return PTR_ERR(rtc); 321 } 322 platform_set_drvdata(pdev, rtc); 323 324 printk(KERN_INFO "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_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 337 AT91_RTC_SECEV | AT91_RTC_TIMEV | 338 AT91_RTC_CALEV); 339 free_irq(AT91_ID_SYS, pdev); 340 341 rtc_device_unregister(rtc); 342 platform_set_drvdata(pdev, NULL); 343 344 return 0; 345 } 346 347 #ifdef CONFIG_PM 348 349 /* AT91RM9200 RTC Power management control */ 350 351 static u32 at91_rtc_imr; 352 353 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state) 354 { 355 /* this IRQ is shared with DBGU and other hardware which isn't 356 * necessarily doing PM like we are... 357 */ 358 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR) 359 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 360 if (at91_rtc_imr) { 361 if (device_may_wakeup(&pdev->dev)) 362 enable_irq_wake(AT91_ID_SYS); 363 else 364 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr); 365 } 366 return 0; 367 } 368 369 static int at91_rtc_resume(struct platform_device *pdev) 370 { 371 if (at91_rtc_imr) { 372 if (device_may_wakeup(&pdev->dev)) 373 disable_irq_wake(AT91_ID_SYS); 374 else 375 at91_sys_write(AT91_RTC_IER, at91_rtc_imr); 376 } 377 return 0; 378 } 379 #else 380 #define at91_rtc_suspend NULL 381 #define at91_rtc_resume NULL 382 #endif 383 384 static struct platform_driver at91_rtc_driver = { 385 .remove = __exit_p(at91_rtc_remove), 386 .suspend = at91_rtc_suspend, 387 .resume = at91_rtc_resume, 388 .driver = { 389 .name = "at91_rtc", 390 .owner = THIS_MODULE, 391 }, 392 }; 393 394 static int __init at91_rtc_init(void) 395 { 396 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe); 397 } 398 399 static void __exit at91_rtc_exit(void) 400 { 401 platform_driver_unregister(&at91_rtc_driver); 402 } 403 404 module_init(at91_rtc_init); 405 module_exit(at91_rtc_exit); 406 407 MODULE_AUTHOR("Rick Bronson"); 408 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 409 MODULE_LICENSE("GPL"); 410