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 #define at91_rtc_read(field) \ 36 __raw_readl(at91_rtc_regs + field) 37 #define at91_rtc_write(field, val) \ 38 __raw_writel((val), at91_rtc_regs + field) 39 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 static void __iomem *at91_rtc_regs; 45 static int irq; 46 47 /* 48 * Decode time/date into rtc_time structure 49 */ 50 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 51 struct rtc_time *tm) 52 { 53 unsigned int time, date; 54 55 /* must read twice in case it changes */ 56 do { 57 time = at91_rtc_read(timereg); 58 date = at91_rtc_read(calreg); 59 } while ((time != at91_rtc_read(timereg)) || 60 (date != at91_rtc_read(calreg))); 61 62 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); 63 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); 64 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); 65 66 /* 67 * The Calendar Alarm register does not have a field for 68 * the year - so these will return an invalid value. When an 69 * alarm is set, at91_alarm_year will store the current year. 70 */ 71 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ 72 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ 73 74 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 75 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; 76 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); 77 } 78 79 /* 80 * Read current time and date in RTC 81 */ 82 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 83 { 84 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 85 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 86 tm->tm_year = tm->tm_year - 1900; 87 88 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 89 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 90 tm->tm_hour, tm->tm_min, tm->tm_sec); 91 92 return 0; 93 } 94 95 /* 96 * Set current time and date in RTC 97 */ 98 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 99 { 100 unsigned long cr; 101 102 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 103 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 104 tm->tm_hour, tm->tm_min, tm->tm_sec); 105 106 /* Stop Time/Calendar from counting */ 107 cr = at91_rtc_read(AT91_RTC_CR); 108 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 109 110 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD); 111 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 112 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); 113 114 at91_rtc_write(AT91_RTC_TIMR, 115 bin2bcd(tm->tm_sec) << 0 116 | bin2bcd(tm->tm_min) << 8 117 | bin2bcd(tm->tm_hour) << 16); 118 119 at91_rtc_write(AT91_RTC_CALR, 120 bin2bcd((tm->tm_year + 1900) / 100) /* century */ 121 | bin2bcd(tm->tm_year % 100) << 8 /* year */ 122 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 123 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 124 | bin2bcd(tm->tm_mday) << 24); 125 126 /* Restart Time/Calendar */ 127 cr = at91_rtc_read(AT91_RTC_CR); 128 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 129 130 return 0; 131 } 132 133 /* 134 * Read alarm time and date in RTC 135 */ 136 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 137 { 138 struct rtc_time *tm = &alrm->time; 139 140 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 141 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 142 tm->tm_year = at91_alarm_year - 1900; 143 144 alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM) 145 ? 1 : 0; 146 147 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 148 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 149 tm->tm_hour, tm->tm_min, tm->tm_sec); 150 151 return 0; 152 } 153 154 /* 155 * Set alarm time and date in RTC 156 */ 157 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 158 { 159 struct rtc_time tm; 160 161 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 162 163 at91_alarm_year = tm.tm_year; 164 165 tm.tm_hour = alrm->time.tm_hour; 166 tm.tm_min = alrm->time.tm_min; 167 tm.tm_sec = alrm->time.tm_sec; 168 169 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 170 at91_rtc_write(AT91_RTC_TIMALR, 171 bin2bcd(tm.tm_sec) << 0 172 | bin2bcd(tm.tm_min) << 8 173 | bin2bcd(tm.tm_hour) << 16 174 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 175 at91_rtc_write(AT91_RTC_CALALR, 176 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 177 | bin2bcd(tm.tm_mday) << 24 178 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 179 180 if (alrm->enabled) { 181 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 182 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 183 } 184 185 pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 186 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 187 tm.tm_min, tm.tm_sec); 188 189 return 0; 190 } 191 192 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 193 { 194 pr_debug("%s(): cmd=%08x\n", __func__, enabled); 195 196 if (enabled) { 197 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 198 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 199 } else 200 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 201 202 return 0; 203 } 204 /* 205 * Provide additional RTC information in /proc/driver/rtc 206 */ 207 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 208 { 209 unsigned long imr = at91_rtc_read(AT91_RTC_IMR); 210 211 seq_printf(seq, "update_IRQ\t: %s\n", 212 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 213 seq_printf(seq, "periodic_IRQ\t: %s\n", 214 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 215 216 return 0; 217 } 218 219 /* 220 * IRQ handler for the RTC 221 */ 222 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 223 { 224 struct platform_device *pdev = dev_id; 225 struct rtc_device *rtc = platform_get_drvdata(pdev); 226 unsigned int rtsr; 227 unsigned long events = 0; 228 229 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR); 230 if (rtsr) { /* this interrupt is shared! Is it ours? */ 231 if (rtsr & AT91_RTC_ALARM) 232 events |= (RTC_AF | RTC_IRQF); 233 if (rtsr & AT91_RTC_SECEV) 234 events |= (RTC_UF | RTC_IRQF); 235 if (rtsr & AT91_RTC_ACKUPD) 236 complete(&at91_rtc_updated); 237 238 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 239 240 rtc_update_irq(rtc, 1, events); 241 242 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__, 243 events >> 8, events & 0x000000FF); 244 245 return IRQ_HANDLED; 246 } 247 return IRQ_NONE; /* not handled */ 248 } 249 250 static const struct rtc_class_ops at91_rtc_ops = { 251 .read_time = at91_rtc_readtime, 252 .set_time = at91_rtc_settime, 253 .read_alarm = at91_rtc_readalarm, 254 .set_alarm = at91_rtc_setalarm, 255 .proc = at91_rtc_proc, 256 .alarm_irq_enable = at91_rtc_alarm_irq_enable, 257 }; 258 259 /* 260 * Initialize and install RTC driver 261 */ 262 static int __init at91_rtc_probe(struct platform_device *pdev) 263 { 264 struct rtc_device *rtc; 265 struct resource *regs; 266 int ret = 0; 267 268 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 269 if (!regs) { 270 dev_err(&pdev->dev, "no mmio resource defined\n"); 271 return -ENXIO; 272 } 273 274 irq = platform_get_irq(pdev, 0); 275 if (irq < 0) { 276 dev_err(&pdev->dev, "no irq resource defined\n"); 277 return -ENXIO; 278 } 279 280 at91_rtc_regs = ioremap(regs->start, resource_size(regs)); 281 if (!at91_rtc_regs) { 282 dev_err(&pdev->dev, "failed to map registers, aborting.\n"); 283 return -ENOMEM; 284 } 285 286 at91_rtc_write(AT91_RTC_CR, 0); 287 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ 288 289 /* Disable all interrupts */ 290 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 291 AT91_RTC_SECEV | AT91_RTC_TIMEV | 292 AT91_RTC_CALEV); 293 294 ret = request_irq(irq, at91_rtc_interrupt, 295 IRQF_SHARED, 296 "at91_rtc", pdev); 297 if (ret) { 298 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n", 299 irq); 300 return ret; 301 } 302 303 /* cpu init code should really have flagged this device as 304 * being wake-capable; if it didn't, do that here. 305 */ 306 if (!device_can_wakeup(&pdev->dev)) 307 device_init_wakeup(&pdev->dev, 1); 308 309 rtc = rtc_device_register(pdev->name, &pdev->dev, 310 &at91_rtc_ops, THIS_MODULE); 311 if (IS_ERR(rtc)) { 312 free_irq(irq, pdev); 313 return PTR_ERR(rtc); 314 } 315 platform_set_drvdata(pdev, rtc); 316 317 printk(KERN_INFO "AT91 Real Time Clock driver.\n"); 318 return 0; 319 } 320 321 /* 322 * Disable and remove the RTC driver 323 */ 324 static int __exit at91_rtc_remove(struct platform_device *pdev) 325 { 326 struct rtc_device *rtc = platform_get_drvdata(pdev); 327 328 /* Disable all interrupts */ 329 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 330 AT91_RTC_SECEV | AT91_RTC_TIMEV | 331 AT91_RTC_CALEV); 332 free_irq(irq, pdev); 333 334 rtc_device_unregister(rtc); 335 platform_set_drvdata(pdev, NULL); 336 337 return 0; 338 } 339 340 #ifdef CONFIG_PM 341 342 /* AT91RM9200 RTC Power management control */ 343 344 static u32 at91_rtc_imr; 345 346 static int at91_rtc_suspend(struct device *dev) 347 { 348 /* this IRQ is shared with DBGU and other hardware which isn't 349 * necessarily doing PM like we are... 350 */ 351 at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR) 352 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 353 if (at91_rtc_imr) { 354 if (device_may_wakeup(dev)) 355 enable_irq_wake(irq); 356 else 357 at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr); 358 } 359 return 0; 360 } 361 362 static int at91_rtc_resume(struct device *dev) 363 { 364 if (at91_rtc_imr) { 365 if (device_may_wakeup(dev)) 366 disable_irq_wake(irq); 367 else 368 at91_rtc_write(AT91_RTC_IER, at91_rtc_imr); 369 } 370 return 0; 371 } 372 373 static const struct dev_pm_ops at91_rtc_pm = { 374 .suspend = at91_rtc_suspend, 375 .resume = at91_rtc_resume, 376 }; 377 378 #define at91_rtc_pm_ptr &at91_rtc_pm 379 380 #else 381 #define at91_rtc_pm_ptr NULL 382 #endif 383 384 static struct platform_driver at91_rtc_driver = { 385 .remove = __exit_p(at91_rtc_remove), 386 .driver = { 387 .name = "at91_rtc", 388 .owner = THIS_MODULE, 389 .pm = at91_rtc_pm_ptr, 390 }, 391 }; 392 393 static int __init at91_rtc_init(void) 394 { 395 return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe); 396 } 397 398 static void __exit at91_rtc_exit(void) 399 { 400 platform_driver_unregister(&at91_rtc_driver); 401 } 402 403 module_init(at91_rtc_init); 404 module_exit(at91_rtc_exit); 405 406 MODULE_AUTHOR("Rick Bronson"); 407 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 408 MODULE_LICENSE("GPL"); 409 MODULE_ALIAS("platform:at91_rtc"); 410