1 /* 2 * drivers/rtc/rtc-spear.c 3 * 4 * Copyright (C) 2010 ST Microelectronics 5 * Rajeev Kumar<rajeev-dlh.kumar@st.com> 6 * 7 * This file is licensed under the terms of the GNU General Public 8 * License version 2. This program is licensed "as is" without any 9 * warranty of any kind, whether express or implied. 10 */ 11 12 #include <linux/bcd.h> 13 #include <linux/clk.h> 14 #include <linux/delay.h> 15 #include <linux/init.h> 16 #include <linux/io.h> 17 #include <linux/irq.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/rtc.h> 21 #include <linux/slab.h> 22 #include <linux/spinlock.h> 23 24 /* RTC registers */ 25 #define TIME_REG 0x00 26 #define DATE_REG 0x04 27 #define ALARM_TIME_REG 0x08 28 #define ALARM_DATE_REG 0x0C 29 #define CTRL_REG 0x10 30 #define STATUS_REG 0x14 31 32 /* TIME_REG & ALARM_TIME_REG */ 33 #define SECONDS_UNITS (0xf<<0) /* seconds units position */ 34 #define SECONDS_TENS (0x7<<4) /* seconds tens position */ 35 #define MINUTES_UNITS (0xf<<8) /* minutes units position */ 36 #define MINUTES_TENS (0x7<<12) /* minutes tens position */ 37 #define HOURS_UNITS (0xf<<16) /* hours units position */ 38 #define HOURS_TENS (0x3<<20) /* hours tens position */ 39 40 /* DATE_REG & ALARM_DATE_REG */ 41 #define DAYS_UNITS (0xf<<0) /* days units position */ 42 #define DAYS_TENS (0x3<<4) /* days tens position */ 43 #define MONTHS_UNITS (0xf<<8) /* months units position */ 44 #define MONTHS_TENS (0x1<<12) /* months tens position */ 45 #define YEARS_UNITS (0xf<<16) /* years units position */ 46 #define YEARS_TENS (0xf<<20) /* years tens position */ 47 #define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */ 48 #define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */ 49 50 /* MASK SHIFT TIME_REG & ALARM_TIME_REG*/ 51 #define SECOND_SHIFT 0x00 /* seconds units */ 52 #define MINUTE_SHIFT 0x08 /* minutes units position */ 53 #define HOUR_SHIFT 0x10 /* hours units position */ 54 #define MDAY_SHIFT 0x00 /* Month day shift */ 55 #define MONTH_SHIFT 0x08 /* Month shift */ 56 #define YEAR_SHIFT 0x10 /* Year shift */ 57 58 #define SECOND_MASK 0x7F 59 #define MIN_MASK 0x7F 60 #define HOUR_MASK 0x3F 61 #define DAY_MASK 0x3F 62 #define MONTH_MASK 0x7F 63 #define YEAR_MASK 0xFFFF 64 65 /* date reg equal to time reg, for debug only */ 66 #define TIME_BYP (1<<9) 67 #define INT_ENABLE (1<<31) /* interrupt enable */ 68 69 /* STATUS_REG */ 70 #define CLK_UNCONNECTED (1<<0) 71 #define PEND_WR_TIME (1<<2) 72 #define PEND_WR_DATE (1<<3) 73 #define LOST_WR_TIME (1<<4) 74 #define LOST_WR_DATE (1<<5) 75 #define RTC_INT_MASK (1<<31) 76 #define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE) 77 #define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE) 78 79 struct spear_rtc_config { 80 struct rtc_device *rtc; 81 struct clk *clk; 82 spinlock_t lock; 83 void __iomem *ioaddr; 84 unsigned int irq_wake; 85 }; 86 87 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config) 88 { 89 unsigned int val; 90 unsigned long flags; 91 92 spin_lock_irqsave(&config->lock, flags); 93 val = readl(config->ioaddr + STATUS_REG); 94 val |= RTC_INT_MASK; 95 writel(val, config->ioaddr + STATUS_REG); 96 spin_unlock_irqrestore(&config->lock, flags); 97 } 98 99 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config) 100 { 101 unsigned int val; 102 103 val = readl(config->ioaddr + CTRL_REG); 104 if (!(val & INT_ENABLE)) { 105 spear_rtc_clear_interrupt(config); 106 val |= INT_ENABLE; 107 writel(val, config->ioaddr + CTRL_REG); 108 } 109 } 110 111 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config) 112 { 113 unsigned int val; 114 115 val = readl(config->ioaddr + CTRL_REG); 116 if (val & INT_ENABLE) { 117 val &= ~INT_ENABLE; 118 writel(val, config->ioaddr + CTRL_REG); 119 } 120 } 121 122 static inline int is_write_complete(struct spear_rtc_config *config) 123 { 124 int ret = 0; 125 unsigned long flags; 126 127 spin_lock_irqsave(&config->lock, flags); 128 if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL) 129 ret = -EIO; 130 spin_unlock_irqrestore(&config->lock, flags); 131 132 return ret; 133 } 134 135 static void rtc_wait_not_busy(struct spear_rtc_config *config) 136 { 137 int status, count = 0; 138 unsigned long flags; 139 140 /* Assuming BUSY may stay active for 80 msec) */ 141 for (count = 0; count < 80; count++) { 142 spin_lock_irqsave(&config->lock, flags); 143 status = readl(config->ioaddr + STATUS_REG); 144 spin_unlock_irqrestore(&config->lock, flags); 145 if ((status & STATUS_BUSY) == 0) 146 break; 147 /* check status busy, after each msec */ 148 msleep(1); 149 } 150 } 151 152 static irqreturn_t spear_rtc_irq(int irq, void *dev_id) 153 { 154 struct spear_rtc_config *config = dev_id; 155 unsigned long flags, events = 0; 156 unsigned int irq_data; 157 158 spin_lock_irqsave(&config->lock, flags); 159 irq_data = readl(config->ioaddr + STATUS_REG); 160 spin_unlock_irqrestore(&config->lock, flags); 161 162 if ((irq_data & RTC_INT_MASK)) { 163 spear_rtc_clear_interrupt(config); 164 events = RTC_IRQF | RTC_AF; 165 rtc_update_irq(config->rtc, 1, events); 166 return IRQ_HANDLED; 167 } else 168 return IRQ_NONE; 169 170 } 171 172 static int tm2bcd(struct rtc_time *tm) 173 { 174 if (rtc_valid_tm(tm) != 0) 175 return -EINVAL; 176 tm->tm_sec = bin2bcd(tm->tm_sec); 177 tm->tm_min = bin2bcd(tm->tm_min); 178 tm->tm_hour = bin2bcd(tm->tm_hour); 179 tm->tm_mday = bin2bcd(tm->tm_mday); 180 tm->tm_mon = bin2bcd(tm->tm_mon + 1); 181 tm->tm_year = bin2bcd(tm->tm_year); 182 183 return 0; 184 } 185 186 static void bcd2tm(struct rtc_time *tm) 187 { 188 tm->tm_sec = bcd2bin(tm->tm_sec); 189 tm->tm_min = bcd2bin(tm->tm_min); 190 tm->tm_hour = bcd2bin(tm->tm_hour); 191 tm->tm_mday = bcd2bin(tm->tm_mday); 192 tm->tm_mon = bcd2bin(tm->tm_mon) - 1; 193 /* epoch == 1900 */ 194 tm->tm_year = bcd2bin(tm->tm_year); 195 } 196 197 /* 198 * spear_rtc_read_time - set the time 199 * @dev: rtc device in use 200 * @tm: holds date and time 201 * 202 * This function read time and date. On success it will return 0 203 * otherwise -ve error is returned. 204 */ 205 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm) 206 { 207 struct spear_rtc_config *config = dev_get_drvdata(dev); 208 unsigned int time, date; 209 210 /* we don't report wday/yday/isdst ... */ 211 rtc_wait_not_busy(config); 212 213 time = readl(config->ioaddr + TIME_REG); 214 date = readl(config->ioaddr + DATE_REG); 215 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; 216 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; 217 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; 218 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; 219 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; 220 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; 221 222 bcd2tm(tm); 223 return 0; 224 } 225 226 /* 227 * spear_rtc_set_time - set the time 228 * @dev: rtc device in use 229 * @tm: holds date and time 230 * 231 * This function set time and date. On success it will return 0 232 * otherwise -ve error is returned. 233 */ 234 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm) 235 { 236 struct spear_rtc_config *config = dev_get_drvdata(dev); 237 unsigned int time, date, err = 0; 238 239 if (tm2bcd(tm) < 0) 240 return -EINVAL; 241 242 rtc_wait_not_busy(config); 243 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) | 244 (tm->tm_hour << HOUR_SHIFT); 245 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) | 246 (tm->tm_year << YEAR_SHIFT); 247 writel(time, config->ioaddr + TIME_REG); 248 writel(date, config->ioaddr + DATE_REG); 249 err = is_write_complete(config); 250 if (err < 0) 251 return err; 252 253 return 0; 254 } 255 256 /* 257 * spear_rtc_read_alarm - read the alarm time 258 * @dev: rtc device in use 259 * @alm: holds alarm date and time 260 * 261 * This function read alarm time and date. On success it will return 0 262 * otherwise -ve error is returned. 263 */ 264 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 265 { 266 struct spear_rtc_config *config = dev_get_drvdata(dev); 267 unsigned int time, date; 268 269 rtc_wait_not_busy(config); 270 271 time = readl(config->ioaddr + ALARM_TIME_REG); 272 date = readl(config->ioaddr + ALARM_DATE_REG); 273 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; 274 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; 275 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; 276 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; 277 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; 278 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; 279 280 bcd2tm(&alm->time); 281 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE; 282 283 return 0; 284 } 285 286 /* 287 * spear_rtc_set_alarm - set the alarm time 288 * @dev: rtc device in use 289 * @alm: holds alarm date and time 290 * 291 * This function set alarm time and date. On success it will return 0 292 * otherwise -ve error is returned. 293 */ 294 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 295 { 296 struct spear_rtc_config *config = dev_get_drvdata(dev); 297 unsigned int time, date, err = 0; 298 299 if (tm2bcd(&alm->time) < 0) 300 return -EINVAL; 301 302 rtc_wait_not_busy(config); 303 304 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min << 305 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT); 306 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon << 307 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT); 308 309 writel(time, config->ioaddr + ALARM_TIME_REG); 310 writel(date, config->ioaddr + ALARM_DATE_REG); 311 err = is_write_complete(config); 312 if (err < 0) 313 return err; 314 315 if (alm->enabled) 316 spear_rtc_enable_interrupt(config); 317 else 318 spear_rtc_disable_interrupt(config); 319 320 return 0; 321 } 322 323 static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled) 324 { 325 struct spear_rtc_config *config = dev_get_drvdata(dev); 326 int ret = 0; 327 328 spear_rtc_clear_interrupt(config); 329 330 switch (enabled) { 331 case 0: 332 /* alarm off */ 333 spear_rtc_disable_interrupt(config); 334 break; 335 case 1: 336 /* alarm on */ 337 spear_rtc_enable_interrupt(config); 338 break; 339 default: 340 ret = -EINVAL; 341 break; 342 } 343 344 return ret; 345 } 346 347 static struct rtc_class_ops spear_rtc_ops = { 348 .read_time = spear_rtc_read_time, 349 .set_time = spear_rtc_set_time, 350 .read_alarm = spear_rtc_read_alarm, 351 .set_alarm = spear_rtc_set_alarm, 352 .alarm_irq_enable = spear_alarm_irq_enable, 353 }; 354 355 static int __devinit spear_rtc_probe(struct platform_device *pdev) 356 { 357 struct resource *res; 358 struct spear_rtc_config *config; 359 unsigned int status = 0; 360 int irq; 361 362 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 363 if (!res) { 364 dev_err(&pdev->dev, "no resource defined\n"); 365 return -EBUSY; 366 } 367 if (!request_mem_region(res->start, resource_size(res), pdev->name)) { 368 dev_err(&pdev->dev, "rtc region already claimed\n"); 369 return -EBUSY; 370 } 371 372 config = kzalloc(sizeof(*config), GFP_KERNEL); 373 if (!config) { 374 dev_err(&pdev->dev, "out of memory\n"); 375 status = -ENOMEM; 376 goto err_release_region; 377 } 378 379 config->clk = clk_get(&pdev->dev, NULL); 380 if (IS_ERR(config->clk)) { 381 status = PTR_ERR(config->clk); 382 goto err_kfree; 383 } 384 385 status = clk_enable(config->clk); 386 if (status < 0) 387 goto err_clk_put; 388 389 config->ioaddr = ioremap(res->start, resource_size(res)); 390 if (!config->ioaddr) { 391 dev_err(&pdev->dev, "ioremap fail\n"); 392 status = -ENOMEM; 393 goto err_disable_clock; 394 } 395 396 spin_lock_init(&config->lock); 397 platform_set_drvdata(pdev, config); 398 399 config->rtc = rtc_device_register(pdev->name, &pdev->dev, 400 &spear_rtc_ops, THIS_MODULE); 401 if (IS_ERR(config->rtc)) { 402 dev_err(&pdev->dev, "can't register RTC device, err %ld\n", 403 PTR_ERR(config->rtc)); 404 status = PTR_ERR(config->rtc); 405 goto err_iounmap; 406 } 407 408 /* alarm irqs */ 409 irq = platform_get_irq(pdev, 0); 410 if (irq < 0) { 411 dev_err(&pdev->dev, "no update irq?\n"); 412 status = irq; 413 goto err_clear_platdata; 414 } 415 416 status = request_irq(irq, spear_rtc_irq, 0, pdev->name, config); 417 if (status) { 418 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \ 419 claimed\n", irq); 420 goto err_clear_platdata; 421 } 422 423 if (!device_can_wakeup(&pdev->dev)) 424 device_init_wakeup(&pdev->dev, 1); 425 426 return 0; 427 428 err_clear_platdata: 429 platform_set_drvdata(pdev, NULL); 430 rtc_device_unregister(config->rtc); 431 err_iounmap: 432 iounmap(config->ioaddr); 433 err_disable_clock: 434 clk_disable(config->clk); 435 err_clk_put: 436 clk_put(config->clk); 437 err_kfree: 438 kfree(config); 439 err_release_region: 440 release_mem_region(res->start, resource_size(res)); 441 442 return status; 443 } 444 445 static int __devexit spear_rtc_remove(struct platform_device *pdev) 446 { 447 struct spear_rtc_config *config = platform_get_drvdata(pdev); 448 int irq; 449 struct resource *res; 450 451 /* leave rtc running, but disable irqs */ 452 spear_rtc_disable_interrupt(config); 453 device_init_wakeup(&pdev->dev, 0); 454 irq = platform_get_irq(pdev, 0); 455 if (irq) 456 free_irq(irq, pdev); 457 clk_disable(config->clk); 458 clk_put(config->clk); 459 iounmap(config->ioaddr); 460 kfree(config); 461 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 462 if (res) 463 release_mem_region(res->start, resource_size(res)); 464 platform_set_drvdata(pdev, NULL); 465 rtc_device_unregister(config->rtc); 466 467 return 0; 468 } 469 470 #ifdef CONFIG_PM 471 472 static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state) 473 { 474 struct spear_rtc_config *config = platform_get_drvdata(pdev); 475 int irq; 476 477 irq = platform_get_irq(pdev, 0); 478 if (device_may_wakeup(&pdev->dev)) { 479 if (!enable_irq_wake(irq)) 480 config->irq_wake = 1; 481 } else { 482 spear_rtc_disable_interrupt(config); 483 clk_disable(config->clk); 484 } 485 486 return 0; 487 } 488 489 static int spear_rtc_resume(struct platform_device *pdev) 490 { 491 struct spear_rtc_config *config = platform_get_drvdata(pdev); 492 int irq; 493 494 irq = platform_get_irq(pdev, 0); 495 496 if (device_may_wakeup(&pdev->dev)) { 497 if (config->irq_wake) { 498 disable_irq_wake(irq); 499 config->irq_wake = 0; 500 } 501 } else { 502 clk_enable(config->clk); 503 spear_rtc_enable_interrupt(config); 504 } 505 506 return 0; 507 } 508 509 #else 510 #define spear_rtc_suspend NULL 511 #define spear_rtc_resume NULL 512 #endif 513 514 static void spear_rtc_shutdown(struct platform_device *pdev) 515 { 516 struct spear_rtc_config *config = platform_get_drvdata(pdev); 517 518 spear_rtc_disable_interrupt(config); 519 clk_disable(config->clk); 520 } 521 522 static struct platform_driver spear_rtc_driver = { 523 .probe = spear_rtc_probe, 524 .remove = __devexit_p(spear_rtc_remove), 525 .suspend = spear_rtc_suspend, 526 .resume = spear_rtc_resume, 527 .shutdown = spear_rtc_shutdown, 528 .driver = { 529 .name = "rtc-spear", 530 }, 531 }; 532 533 module_platform_driver(spear_rtc_driver); 534 535 MODULE_ALIAS("platform:rtc-spear"); 536 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>"); 537 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); 538 MODULE_LICENSE("GPL"); 539