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_AIE_OFF: /* alarm off */ 199 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM); 200 break; 201 case RTC_AIE_ON: /* alarm on */ 202 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 203 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM); 204 break; 205 case RTC_UIE_OFF: /* update off */ 206 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV); 207 break; 208 case RTC_UIE_ON: /* update on */ 209 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV); 210 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV); 211 break; 212 default: 213 ret = -ENOIOCTLCMD; 214 break; 215 } 216 217 return ret; 218 } 219 220 /* 221 * Provide additional RTC information in /proc/driver/rtc 222 */ 223 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 224 { 225 unsigned long imr = at91_sys_read(AT91_RTC_IMR); 226 227 seq_printf(seq, "update_IRQ\t: %s\n", 228 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 229 seq_printf(seq, "periodic_IRQ\t: %s\n", 230 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 231 232 return 0; 233 } 234 235 /* 236 * IRQ handler for the RTC 237 */ 238 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 239 { 240 struct platform_device *pdev = dev_id; 241 struct rtc_device *rtc = platform_get_drvdata(pdev); 242 unsigned int rtsr; 243 unsigned long events = 0; 244 245 rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR); 246 if (rtsr) { /* this interrupt is shared! Is it ours? */ 247 if (rtsr & AT91_RTC_ALARM) 248 events |= (RTC_AF | RTC_IRQF); 249 if (rtsr & AT91_RTC_SECEV) 250 events |= (RTC_UF | RTC_IRQF); 251 if (rtsr & AT91_RTC_ACKUPD) 252 complete(&at91_rtc_updated); 253 254 at91_sys_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 255 256 rtc_update_irq(rtc, 1, events); 257 258 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__, 259 events >> 8, events & 0x000000FF); 260 261 return IRQ_HANDLED; 262 } 263 return IRQ_NONE; /* not handled */ 264 } 265 266 static const struct rtc_class_ops at91_rtc_ops = { 267 .ioctl = at91_rtc_ioctl, 268 .read_time = at91_rtc_readtime, 269 .set_time = at91_rtc_settime, 270 .read_alarm = at91_rtc_readalarm, 271 .set_alarm = at91_rtc_setalarm, 272 .proc = at91_rtc_proc, 273 }; 274 275 /* 276 * Initialize and install RTC driver 277 */ 278 static int __init at91_rtc_probe(struct platform_device *pdev) 279 { 280 struct rtc_device *rtc; 281 int ret; 282 283 at91_sys_write(AT91_RTC_CR, 0); 284 at91_sys_write(AT91_RTC_MR, 0); /* 24 hour mode */ 285 286 /* Disable all interrupts */ 287 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 288 AT91_RTC_SECEV | AT91_RTC_TIMEV | 289 AT91_RTC_CALEV); 290 291 ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt, 292 IRQF_DISABLED | IRQF_SHARED, 293 "at91_rtc", pdev); 294 if (ret) { 295 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", 296 AT91_ID_SYS); 297 return ret; 298 } 299 300 /* cpu init code should really have flagged this device as 301 * being wake-capable; if it didn't, do that here. 302 */ 303 if (!device_can_wakeup(&pdev->dev)) 304 device_init_wakeup(&pdev->dev, 1); 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); 313 314 printk(KERN_INFO "AT91 Real Time Clock driver.\n"); 315 return 0; 316 } 317 318 /* 319 * Disable and remove the RTC driver 320 */ 321 static int __exit at91_rtc_remove(struct platform_device *pdev) 322 { 323 struct rtc_device *rtc = platform_get_drvdata(pdev); 324 325 /* Disable all interrupts */ 326 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 327 AT91_RTC_SECEV | AT91_RTC_TIMEV | 328 AT91_RTC_CALEV); 329 free_irq(AT91_ID_SYS, pdev); 330 331 rtc_device_unregister(rtc); 332 platform_set_drvdata(pdev, NULL); 333 334 return 0; 335 } 336 337 #ifdef CONFIG_PM 338 339 /* AT91RM9200 RTC Power management control */ 340 341 static u32 at91_rtc_imr; 342 343 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state) 344 { 345 /* this IRQ is shared with DBGU and other hardware which isn't 346 * necessarily doing PM like we are... 347 */ 348 at91_rtc_imr = at91_sys_read(AT91_RTC_IMR) 349 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 350 if (at91_rtc_imr) { 351 if (device_may_wakeup(&pdev->dev)) 352 enable_irq_wake(AT91_ID_SYS); 353 else 354 at91_sys_write(AT91_RTC_IDR, at91_rtc_imr); 355 } 356 return 0; 357 } 358 359 static int at91_rtc_resume(struct platform_device *pdev) 360 { 361 if (at91_rtc_imr) { 362 if (device_may_wakeup(&pdev->dev)) 363 disable_irq_wake(AT91_ID_SYS); 364 else 365 at91_sys_write(AT91_RTC_IER, at91_rtc_imr); 366 } 367 return 0; 368 } 369 #else 370 #define at91_rtc_suspend NULL 371 #define at91_rtc_resume NULL 372 #endif 373 374 static struct platform_driver at91_rtc_driver = { 375 .remove = __exit_p(at91_rtc_remove), 376 .suspend = at91_rtc_suspend, 377 .resume = at91_rtc_resume, 378 .driver = { 379 .name = "at91_rtc", 380 .owner = THIS_MODULE, 381 }, 382 }; 383 384 static int __init at91_rtc_init(void) 385 { 386 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe); 387 } 388 389 static void __exit at91_rtc_exit(void) 390 { 391 platform_driver_unregister(&at91_rtc_driver); 392 } 393 394 module_init(at91_rtc_init); 395 module_exit(at91_rtc_exit); 396 397 MODULE_AUTHOR("Rick Bronson"); 398 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 399 MODULE_LICENSE("GPL"); 400 MODULE_ALIAS("platform:at91_rtc"); 401