| 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_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 device *dev) |
| 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(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 device *dev) |
| 360 | { |
| 361 | if (at91_rtc_imr) { |
| 362 | if (device_may_wakeup(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 | |
| 370 | static const struct dev_pm_ops at91_rtc_pm = { |
| 371 | .suspend = at91_rtc_suspend, |
| 372 | .resume = at91_rtc_resume, |
| 373 | }; |
| 374 | |
| 375 | #define at91_rtc_pm_ptr &at91_rtc_pm |
| 376 | |
| 377 | #else |
| 378 | #define at91_rtc_pm_ptr NULL |
| 379 | #endif |
| 380 | |
| 381 | static struct platform_driver at91_rtc_driver = { |
| 382 | .remove = __exit_p(at91_rtc_remove), |
| 383 | .driver = { |
| 384 | .name = "at91_rtc", |
| 385 | .owner = THIS_MODULE, |
| 386 | .pm = at91_rtc_pm_ptr, |
| 387 | }, |
| 388 | }; |
| 389 | |
| 390 | static int __init at91_rtc_init(void) |
| 391 | { |
| 392 | return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe); |
| 393 | } |
| 394 | |
| 395 | static void __exit at91_rtc_exit(void) |
| 396 | { |
| 397 | platform_driver_unregister(&at91_rtc_driver); |
| 398 | } |
| 399 | |
| 400 | module_init(at91_rtc_init); |
| 401 | module_exit(at91_rtc_exit); |
| 402 | |
| 403 | MODULE_AUTHOR("Rick Bronson"); |
| 404 | MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200"); |
| 405 | MODULE_LICENSE("GPL"); |
| 406 | MODULE_ALIAS("platform:at91_rtc"); |