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 #include <linux/of.h> 32 #include <linux/of_device.h> 33 34 #include <asm/uaccess.h> 35 36 #include "rtc-at91rm9200.h" 37 38 #define at91_rtc_read(field) \ 39 __raw_readl(at91_rtc_regs + field) 40 #define at91_rtc_write(field, val) \ 41 __raw_writel((val), at91_rtc_regs + field) 42 43 #define AT91_RTC_EPOCH 1900UL /* just like arch/arm/common/rtctime.c */ 44 45 static DECLARE_COMPLETION(at91_rtc_updated); 46 static unsigned int at91_alarm_year = AT91_RTC_EPOCH; 47 static void __iomem *at91_rtc_regs; 48 static int irq; 49 50 /* 51 * Decode time/date into rtc_time structure 52 */ 53 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg, 54 struct rtc_time *tm) 55 { 56 unsigned int time, date; 57 58 /* must read twice in case it changes */ 59 do { 60 time = at91_rtc_read(timereg); 61 date = at91_rtc_read(calreg); 62 } while ((time != at91_rtc_read(timereg)) || 63 (date != at91_rtc_read(calreg))); 64 65 tm->tm_sec = bcd2bin((time & AT91_RTC_SEC) >> 0); 66 tm->tm_min = bcd2bin((time & AT91_RTC_MIN) >> 8); 67 tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16); 68 69 /* 70 * The Calendar Alarm register does not have a field for 71 * the year - so these will return an invalid value. When an 72 * alarm is set, at91_alarm_year will store the current year. 73 */ 74 tm->tm_year = bcd2bin(date & AT91_RTC_CENT) * 100; /* century */ 75 tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8); /* year */ 76 77 tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */ 78 tm->tm_mon = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1; 79 tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24); 80 } 81 82 /* 83 * Read current time and date in RTC 84 */ 85 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm) 86 { 87 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm); 88 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 89 tm->tm_year = tm->tm_year - 1900; 90 91 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 92 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 93 tm->tm_hour, tm->tm_min, tm->tm_sec); 94 95 return 0; 96 } 97 98 /* 99 * Set current time and date in RTC 100 */ 101 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 102 { 103 unsigned long cr; 104 105 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 106 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 107 tm->tm_hour, tm->tm_min, tm->tm_sec); 108 109 /* Stop Time/Calendar from counting */ 110 cr = at91_rtc_read(AT91_RTC_CR); 111 at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); 112 113 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD); 114 wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */ 115 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD); 116 117 at91_rtc_write(AT91_RTC_TIMR, 118 bin2bcd(tm->tm_sec) << 0 119 | bin2bcd(tm->tm_min) << 8 120 | bin2bcd(tm->tm_hour) << 16); 121 122 at91_rtc_write(AT91_RTC_CALR, 123 bin2bcd((tm->tm_year + 1900) / 100) /* century */ 124 | bin2bcd(tm->tm_year % 100) << 8 /* year */ 125 | bin2bcd(tm->tm_mon + 1) << 16 /* tm_mon starts at zero */ 126 | bin2bcd(tm->tm_wday + 1) << 21 /* day of the week [0-6], Sunday=0 */ 127 | bin2bcd(tm->tm_mday) << 24); 128 129 /* Restart Time/Calendar */ 130 cr = at91_rtc_read(AT91_RTC_CR); 131 at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); 132 133 return 0; 134 } 135 136 /* 137 * Read alarm time and date in RTC 138 */ 139 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 140 { 141 struct rtc_time *tm = &alrm->time; 142 143 at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm); 144 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 145 tm->tm_year = at91_alarm_year - 1900; 146 147 alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM) 148 ? 1 : 0; 149 150 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 151 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, 152 tm->tm_hour, tm->tm_min, tm->tm_sec); 153 154 return 0; 155 } 156 157 /* 158 * Set alarm time and date in RTC 159 */ 160 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 161 { 162 struct rtc_time tm; 163 164 at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm); 165 166 at91_alarm_year = tm.tm_year; 167 168 tm.tm_hour = alrm->time.tm_hour; 169 tm.tm_min = alrm->time.tm_min; 170 tm.tm_sec = alrm->time.tm_sec; 171 172 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 173 at91_rtc_write(AT91_RTC_TIMALR, 174 bin2bcd(tm.tm_sec) << 0 175 | bin2bcd(tm.tm_min) << 8 176 | bin2bcd(tm.tm_hour) << 16 177 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN); 178 at91_rtc_write(AT91_RTC_CALALR, 179 bin2bcd(tm.tm_mon + 1) << 16 /* tm_mon starts at zero */ 180 | bin2bcd(tm.tm_mday) << 24 181 | AT91_RTC_DATEEN | AT91_RTC_MTHEN); 182 183 if (alrm->enabled) { 184 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 185 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 186 } 187 188 dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__, 189 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, 190 tm.tm_min, tm.tm_sec); 191 192 return 0; 193 } 194 195 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 196 { 197 dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled); 198 199 if (enabled) { 200 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM); 201 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM); 202 } else 203 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM); 204 205 return 0; 206 } 207 /* 208 * Provide additional RTC information in /proc/driver/rtc 209 */ 210 static int at91_rtc_proc(struct device *dev, struct seq_file *seq) 211 { 212 unsigned long imr = at91_rtc_read(AT91_RTC_IMR); 213 214 seq_printf(seq, "update_IRQ\t: %s\n", 215 (imr & AT91_RTC_ACKUPD) ? "yes" : "no"); 216 seq_printf(seq, "periodic_IRQ\t: %s\n", 217 (imr & AT91_RTC_SECEV) ? "yes" : "no"); 218 219 return 0; 220 } 221 222 /* 223 * IRQ handler for the RTC 224 */ 225 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 226 { 227 struct platform_device *pdev = dev_id; 228 struct rtc_device *rtc = platform_get_drvdata(pdev); 229 unsigned int rtsr; 230 unsigned long events = 0; 231 232 rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR); 233 if (rtsr) { /* this interrupt is shared! Is it ours? */ 234 if (rtsr & AT91_RTC_ALARM) 235 events |= (RTC_AF | RTC_IRQF); 236 if (rtsr & AT91_RTC_SECEV) 237 events |= (RTC_UF | RTC_IRQF); 238 if (rtsr & AT91_RTC_ACKUPD) 239 complete(&at91_rtc_updated); 240 241 at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ 242 243 rtc_update_irq(rtc, 1, events); 244 245 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__, 246 events >> 8, events & 0x000000FF); 247 248 return IRQ_HANDLED; 249 } 250 return IRQ_NONE; /* not handled */ 251 } 252 253 static const struct rtc_class_ops at91_rtc_ops = { 254 .read_time = at91_rtc_readtime, 255 .set_time = at91_rtc_settime, 256 .read_alarm = at91_rtc_readalarm, 257 .set_alarm = at91_rtc_setalarm, 258 .proc = at91_rtc_proc, 259 .alarm_irq_enable = at91_rtc_alarm_irq_enable, 260 }; 261 262 /* 263 * Initialize and install RTC driver 264 */ 265 static int __init at91_rtc_probe(struct platform_device *pdev) 266 { 267 struct rtc_device *rtc; 268 struct resource *regs; 269 int ret = 0; 270 271 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 272 if (!regs) { 273 dev_err(&pdev->dev, "no mmio resource defined\n"); 274 return -ENXIO; 275 } 276 277 irq = platform_get_irq(pdev, 0); 278 if (irq < 0) { 279 dev_err(&pdev->dev, "no irq resource defined\n"); 280 return -ENXIO; 281 } 282 283 at91_rtc_regs = ioremap(regs->start, resource_size(regs)); 284 if (!at91_rtc_regs) { 285 dev_err(&pdev->dev, "failed to map registers, aborting.\n"); 286 return -ENOMEM; 287 } 288 289 at91_rtc_write(AT91_RTC_CR, 0); 290 at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */ 291 292 /* Disable all interrupts */ 293 at91_rtc_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(irq, at91_rtc_interrupt, 298 IRQF_SHARED, 299 "at91_rtc", pdev); 300 if (ret) { 301 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq); 302 goto err_unmap; 303 } 304 305 /* cpu init code should really have flagged this device as 306 * being wake-capable; if it didn't, do that here. 307 */ 308 if (!device_can_wakeup(&pdev->dev)) 309 device_init_wakeup(&pdev->dev, 1); 310 311 rtc = rtc_device_register(pdev->name, &pdev->dev, 312 &at91_rtc_ops, THIS_MODULE); 313 if (IS_ERR(rtc)) { 314 ret = PTR_ERR(rtc); 315 goto err_free_irq; 316 } 317 platform_set_drvdata(pdev, rtc); 318 319 dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); 320 return 0; 321 322 err_free_irq: 323 free_irq(irq, pdev); 324 err_unmap: 325 iounmap(at91_rtc_regs); 326 327 return ret; 328 } 329 330 /* 331 * Disable and remove the RTC driver 332 */ 333 static int __exit at91_rtc_remove(struct platform_device *pdev) 334 { 335 struct rtc_device *rtc = platform_get_drvdata(pdev); 336 337 /* Disable all interrupts */ 338 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM | 339 AT91_RTC_SECEV | AT91_RTC_TIMEV | 340 AT91_RTC_CALEV); 341 free_irq(irq, pdev); 342 343 rtc_device_unregister(rtc); 344 iounmap(at91_rtc_regs); 345 platform_set_drvdata(pdev, NULL); 346 347 return 0; 348 } 349 350 #ifdef CONFIG_PM_SLEEP 351 352 /* AT91RM9200 RTC Power management control */ 353 354 static u32 at91_rtc_imr; 355 356 static int at91_rtc_suspend(struct device *dev) 357 { 358 /* this IRQ is shared with DBGU and other hardware which isn't 359 * necessarily doing PM like we are... 360 */ 361 at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR) 362 & (AT91_RTC_ALARM|AT91_RTC_SECEV); 363 if (at91_rtc_imr) { 364 if (device_may_wakeup(dev)) 365 enable_irq_wake(irq); 366 else 367 at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr); 368 } 369 return 0; 370 } 371 372 static int at91_rtc_resume(struct device *dev) 373 { 374 if (at91_rtc_imr) { 375 if (device_may_wakeup(dev)) 376 disable_irq_wake(irq); 377 else 378 at91_rtc_write(AT91_RTC_IER, at91_rtc_imr); 379 } 380 return 0; 381 } 382 #endif 383 384 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume); 385 386 static const struct of_device_id at91_rtc_dt_ids[] = { 387 { .compatible = "atmel,at91rm9200-rtc" }, 388 { /* sentinel */ } 389 }; 390 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids); 391 392 static struct platform_driver at91_rtc_driver = { 393 .remove = __exit_p(at91_rtc_remove), 394 .driver = { 395 .name = "at91_rtc", 396 .owner = THIS_MODULE, 397 .pm = &at91_rtc_pm_ops, 398 .of_match_table = of_match_ptr(at91_rtc_dt_ids), 399 }, 400 }; 401 402 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe); 403 404 MODULE_AUTHOR("Rick Bronson"); 405 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); 406 MODULE_LICENSE("GPL"); 407 MODULE_ALIAS("platform:at91_rtc"); 408