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 48 /* 49 * Decode time/date into rtc_time structure 50 */ 51 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 52 struct rtc_time *tm) 53 { 54 unsigned int time, date; 55 56 /* must read twice in case it changes */ 57 do { 58 time = at91_rtc_read(timereg); 59 date = at91_rtc_read(calreg); 60 } while ((time != at91_rtc_read(timereg)) || 61 (date != at91_rtc_read(calreg))); 62 63 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); 64 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); 65 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); 66 67 /* 68 * The Calendar Alarm register does not have a field for 69 * the year - so these will return an invalid value. When an 70 * alarm is set, at91_alarm_year will store the current year. 71 */ 72 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ 73 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ 74 75 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 76 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; 77 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); 78 } 79 80 /* 81 * Read current time and date in RTC 82 */ 83 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 84 { 85 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 86 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 87 tm->tm_year = tm->tm_year - 1900; 88 89 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 90 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 91 tm->tm_hour, tm->tm_min, tm->tm_sec); 92 93 return 0; 94 } 95 96 /* 97 * Set current time and date in RTC 98 */ 99 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 100 { 101 unsigned long cr; 102 103 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 104 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 105 tm->tm_hour, tm->tm_min, tm->tm_sec); 106 107 /* Stop Time/Calendar from counting */ 108 cr = at91_rtc_read(AT91_RTC_CR); 109 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 110 111 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD); 112 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 113 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); 114 115 at91_rtc_write(AT91_RTC_TIMR, 116 bin2bcd(tm->tm_sec) << 0 117 | bin2bcd(tm->tm_min) << 8 118 | bin2bcd(tm->tm_hour) << 16); 119 120 at91_rtc_write(AT91_RTC_CALR, 121 bin2bcd((tm->tm_year + 1900) / 100) /* century */ 122 | bin2bcd(tm->tm_year % 100) << 8 /* year */ 123 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 124 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 125 | bin2bcd(tm->tm_mday) << 24); 126 127 /* Restart Time/Calendar */ 128 cr = at91_rtc_read(AT91_RTC_CR); 129 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 130 131 return 0; 132 } 133 134 /* 135 * Read alarm time and date in RTC 136 */ 137 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 138 { 139 struct rtc_time *tm = &alrm->time; 140 141 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 142 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 143 tm->tm_year = at91_alarm_year - 1900; 144 145 alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM) 146 ? 1 : 0; 147 148 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 149 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 150 tm->tm_hour, tm->tm_min, tm->tm_sec); 151 152 return 0; 153 } 154 155 /* 156 * Set alarm time and date in RTC 157 */ 158 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 159 { 160 struct rtc_time tm; 161 162 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 163 164 at91_alarm_year = tm.tm_year; 165 166 tm.tm_hour = alrm->time.tm_hour; 167 tm.tm_min = alrm->time.tm_min; 168 tm.tm_sec = alrm->time.tm_sec; 169 170 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 171 at91_rtc_write(AT91_RTC_TIMALR, 172 bin2bcd(tm.tm_sec) << 0 173 | bin2bcd(tm.tm_min) << 8 174 | bin2bcd(tm.tm_hour) << 16 175 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 176 at91_rtc_write(AT91_RTC_CALALR, 177 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 178 | bin2bcd(tm.tm_mday) << 24 179 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 180 181 if (alrm->enabled) { 182 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 183 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 184 } 185 186 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 187 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 188 tm.tm_min, tm.tm_sec); 189 190 return 0; 191 } 192 193 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 194 { 195 pr_debug("%s(): cmd=%08x\n", __func__, enabled); 196 197 if (enabled) { 198 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 199 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 200 } else 201 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 202 203 return 0; 204 } 205 /* 206 * Provide additional RTC information in /proc/driver/rtc 207 */ 208 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 209 { 210 unsigned long imr = at91_rtc_read(AT91_RTC_IMR); 211 212 seq_printf(seq, "update_IRQ\t: %s\n", 213 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 214 seq_printf(seq, "periodic_IRQ\t: %s\n", 215 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 216 217 return 0; 218 } 219 220 /* 221 * IRQ handler for the RTC 222 */ 223 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 224 { 225 struct platform_device *pdev = dev_id; 226 struct rtc_device *rtc = platform_get_drvdata(pdev); 227 unsigned int rtsr; 228 unsigned long events = 0; 229 230 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR); 231 if (rtsr) { /* this interrupt is shared! Is it ours? */ 232 if (rtsr & AT91_RTC_ALARM) 233 events |= (RTC_AF | RTC_IRQF); 234 if (rtsr & AT91_RTC_SECEV) 235 events |= (RTC_UF | RTC_IRQF); 236 if (rtsr & AT91_RTC_ACKUPD) 237 complete(&at91_rtc_updated); 238 239 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 240 241 rtc_update_irq(rtc, 1, events); 242 243 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__, 244 events >> 8, events & 0x000000FF); 245 246 return IRQ_HANDLED; 247 } 248 return IRQ_NONE; /* not handled */ 249 } 250 251 static const struct rtc_class_ops at91_rtc_ops = { 252 .read_time = at91_rtc_readtime, 253 .set_time = at91_rtc_settime, 254 .read_alarm = at91_rtc_readalarm, 255 .set_alarm = at91_rtc_setalarm, 256 .proc = at91_rtc_proc, 257 .alarm_irq_enable = at91_rtc_alarm_irq_enable, 258 }; 259 260 /* 261 * Initialize and install RTC driver 262 */ 263 static int __init at91_rtc_probe(struct platform_device *pdev) 264 { 265 struct rtc_device *rtc; 266 struct resource *regs; 267 int ret = 0; 268 269 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 270 if (!regs) { 271 dev_err(&pdev->dev, "no mmio resource defined\n"); 272 return -ENXIO; 273 } 274 275 irq = platform_get_irq(pdev, 0); 276 if (irq < 0) { 277 dev_err(&pdev->dev, "no irq resource defined\n"); 278 return -ENXIO; 279 } 280 281 at91_rtc_regs = ioremap(regs->start, resource_size(regs)); 282 if (!at91_rtc_regs) { 283 dev_err(&pdev->dev, "failed to map registers, aborting.\n"); 284 return -ENOMEM; 285 } 286 287 at91_rtc_write(AT91_RTC_CR, 0); 288 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ 289 290 /* Disable all interrupts */ 291 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 292 AT91_RTC_SECEV | AT91_RTC_TIMEV | 293 AT91_RTC_CALEV); 294 295 ret = request_irq(irq, at91_rtc_interrupt, 296 IRQF_SHARED, 297 "at91_rtc", pdev); 298 if (ret) { 299 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", 300 irq); 301 return ret; 302 } 303 304 /* cpu init code should really have flagged this device as 305 * being wake-capable; if it didn't, do that here. 306 */ 307 if (!device_can_wakeup(&pdev->dev)) 308 device_init_wakeup(&pdev->dev, 1); 309 310 rtc = rtc_device_register(pdev->name, &pdev->dev, 311 &at91_rtc_ops, THIS_MODULE); 312 if (IS_ERR(rtc)) { 313 free_irq(irq, pdev); 314 return PTR_ERR(rtc); 315 } 316 platform_set_drvdata(pdev, rtc); 317 318 printk(KERN_INFO "AT91 Real Time Clock driver.\n"); 319 return 0; 320 } 321 322 /* 323 * Disable and remove the RTC driver 324 */ 325 static int __exit at91_rtc_remove(struct platform_device *pdev) 326 { 327 struct rtc_device *rtc = platform_get_drvdata(pdev); 328 329 /* Disable all interrupts */ 330 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 331 AT91_RTC_SECEV | AT91_RTC_TIMEV | 332 AT91_RTC_CALEV); 333 free_irq(irq, pdev); 334 335 rtc_device_unregister(rtc); 336 platform_set_drvdata(pdev, NULL); 337 338 return 0; 339 } 340 341 #ifdef CONFIG_PM 342 343 /* AT91RM9200 RTC Power management control */ 344 345 static u32 at91_rtc_imr; 346 347 static int at91_rtc_suspend(struct device *dev) 348 { 349 /* this IRQ is shared with DBGU and other hardware which isn't 350 * necessarily doing PM like we are... 351 */ 352 at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR) 353 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 354 if (at91_rtc_imr) { 355 if (device_may_wakeup(dev)) 356 enable_irq_wake(irq); 357 else 358 at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr); 359 } 360 return 0; 361 } 362 363 static int at91_rtc_resume(struct device *dev) 364 { 365 if (at91_rtc_imr) { 366 if (device_may_wakeup(dev)) 367 disable_irq_wake(irq); 368 else 369 at91_rtc_write(AT91_RTC_IER, at91_rtc_imr); 370 } 371 return 0; 372 } 373 374 static const struct dev_pm_ops at91_rtc_pm = { 375 .suspend = at91_rtc_suspend, 376 .resume = at91_rtc_resume, 377 }; 378 379 #define at91_rtc_pm_ptr &at91_rtc_pm 380 381 #else 382 #define at91_rtc_pm_ptr NULL 383 #endif 384 385 static struct platform_driver at91_rtc_driver = { 386 .remove = __exit_p(at91_rtc_remove), 387 .driver = { 388 .name = "at91_rtc", 389 .owner = THIS_MODULE, 390 .pm = at91_rtc_pm_ptr, 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 MODULE_ALIAS("platform:at91_rtc"); 411