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 clk *clk; 81 spinlock_t lock; 82 void __iomem *ioaddr; 83 }; 84 85 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config) 86 { 87 unsigned int val; 88 unsigned long flags; 89 90 spin_lock_irqsave(&config->lock, flags); 91 val = readl(config->ioaddr + STATUS_REG); 92 val |= RTC_INT_MASK; 93 writel(val, config->ioaddr + STATUS_REG); 94 spin_unlock_irqrestore(&config->lock, flags); 95 } 96 97 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config) 98 { 99 unsigned int val; 100 101 val = readl(config->ioaddr + CTRL_REG); 102 if (!(val & INT_ENABLE)) { 103 spear_rtc_clear_interrupt(config); 104 val |= INT_ENABLE; 105 writel(val, config->ioaddr + CTRL_REG); 106 } 107 } 108 109 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config) 110 { 111 unsigned int val; 112 113 val = readl(config->ioaddr + CTRL_REG); 114 if (val & INT_ENABLE) { 115 val &= ~INT_ENABLE; 116 writel(val, config->ioaddr + CTRL_REG); 117 } 118 } 119 120 static inline int is_write_complete(struct spear_rtc_config *config) 121 { 122 int ret = 0; 123 unsigned long flags; 124 125 spin_lock_irqsave(&config->lock, flags); 126 if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL) 127 ret = -EIO; 128 spin_unlock_irqrestore(&config->lock, flags); 129 130 return ret; 131 } 132 133 static void rtc_wait_not_busy(struct spear_rtc_config *config) 134 { 135 int status, count = 0; 136 unsigned long flags; 137 138 /* Assuming BUSY may stay active for 80 msec) */ 139 for (count = 0; count < 80; count++) { 140 spin_lock_irqsave(&config->lock, flags); 141 status = readl(config->ioaddr + STATUS_REG); 142 spin_unlock_irqrestore(&config->lock, flags); 143 if ((status & STATUS_BUSY) == 0) 144 break; 145 /* check status busy, after each msec */ 146 msleep(1); 147 } 148 } 149 150 static irqreturn_t spear_rtc_irq(int irq, void *dev_id) 151 { 152 struct rtc_device *rtc = (struct rtc_device *)dev_id; 153 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 154 unsigned long flags, events = 0; 155 unsigned int irq_data; 156 157 spin_lock_irqsave(&config->lock, flags); 158 irq_data = readl(config->ioaddr + STATUS_REG); 159 spin_unlock_irqrestore(&config->lock, flags); 160 161 if ((irq_data & RTC_INT_MASK)) { 162 spear_rtc_clear_interrupt(config); 163 events = RTC_IRQF | RTC_AF; 164 rtc_update_irq(rtc, 1, events); 165 return IRQ_HANDLED; 166 } else 167 return IRQ_NONE; 168 169 } 170 171 static int tm2bcd(struct rtc_time *tm) 172 { 173 if (rtc_valid_tm(tm) != 0) 174 return -EINVAL; 175 tm->tm_sec = bin2bcd(tm->tm_sec); 176 tm->tm_min = bin2bcd(tm->tm_min); 177 tm->tm_hour = bin2bcd(tm->tm_hour); 178 tm->tm_mday = bin2bcd(tm->tm_mday); 179 tm->tm_mon = bin2bcd(tm->tm_mon + 1); 180 tm->tm_year = bin2bcd(tm->tm_year); 181 182 return 0; 183 } 184 185 static void bcd2tm(struct rtc_time *tm) 186 { 187 tm->tm_sec = bcd2bin(tm->tm_sec); 188 tm->tm_min = bcd2bin(tm->tm_min); 189 tm->tm_hour = bcd2bin(tm->tm_hour); 190 tm->tm_mday = bcd2bin(tm->tm_mday); 191 tm->tm_mon = bcd2bin(tm->tm_mon) - 1; 192 /* epoch == 1900 */ 193 tm->tm_year = bcd2bin(tm->tm_year); 194 } 195 196 /* 197 * spear_rtc_read_time - set the time 198 * @dev: rtc device in use 199 * @tm: holds date and time 200 * 201 * This function read time and date. On success it will return 0 202 * otherwise -ve error is returned. 203 */ 204 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm) 205 { 206 struct platform_device *pdev = to_platform_device(dev); 207 struct rtc_device *rtc = platform_get_drvdata(pdev); 208 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 209 unsigned int time, date; 210 211 /* we don't report wday/yday/isdst ... */ 212 rtc_wait_not_busy(config); 213 214 time = readl(config->ioaddr + TIME_REG); 215 date = readl(config->ioaddr + DATE_REG); 216 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; 217 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; 218 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; 219 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; 220 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; 221 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; 222 223 bcd2tm(tm); 224 return 0; 225 } 226 227 /* 228 * spear_rtc_set_time - set the time 229 * @dev: rtc device in use 230 * @tm: holds date and time 231 * 232 * This function set time and date. On success it will return 0 233 * otherwise -ve error is returned. 234 */ 235 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm) 236 { 237 struct platform_device *pdev = to_platform_device(dev); 238 struct rtc_device *rtc = platform_get_drvdata(pdev); 239 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 240 unsigned int time, date, err = 0; 241 242 if (tm2bcd(tm) < 0) 243 return -EINVAL; 244 245 rtc_wait_not_busy(config); 246 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) | 247 (tm->tm_hour << HOUR_SHIFT); 248 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) | 249 (tm->tm_year << YEAR_SHIFT); 250 writel(time, config->ioaddr + TIME_REG); 251 writel(date, config->ioaddr + DATE_REG); 252 err = is_write_complete(config); 253 if (err < 0) 254 return err; 255 256 return 0; 257 } 258 259 /* 260 * spear_rtc_read_alarm - read the alarm time 261 * @dev: rtc device in use 262 * @alm: holds alarm date and time 263 * 264 * This function read alarm time and date. On success it will return 0 265 * otherwise -ve error is returned. 266 */ 267 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 268 { 269 struct platform_device *pdev = to_platform_device(dev); 270 struct rtc_device *rtc = platform_get_drvdata(pdev); 271 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 272 unsigned int time, date; 273 274 rtc_wait_not_busy(config); 275 276 time = readl(config->ioaddr + ALARM_TIME_REG); 277 date = readl(config->ioaddr + ALARM_DATE_REG); 278 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; 279 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; 280 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; 281 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; 282 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; 283 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; 284 285 bcd2tm(&alm->time); 286 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE; 287 288 return 0; 289 } 290 291 /* 292 * spear_rtc_set_alarm - set the alarm time 293 * @dev: rtc device in use 294 * @alm: holds alarm date and time 295 * 296 * This function set alarm time and date. On success it will return 0 297 * otherwise -ve error is returned. 298 */ 299 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 300 { 301 struct platform_device *pdev = to_platform_device(dev); 302 struct rtc_device *rtc = platform_get_drvdata(pdev); 303 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 304 unsigned int time, date, err = 0; 305 306 if (tm2bcd(&alm->time) < 0) 307 return -EINVAL; 308 309 rtc_wait_not_busy(config); 310 311 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min << 312 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT); 313 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon << 314 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT); 315 316 writel(time, config->ioaddr + ALARM_TIME_REG); 317 writel(date, config->ioaddr + ALARM_DATE_REG); 318 err = is_write_complete(config); 319 if (err < 0) 320 return err; 321 322 if (alm->enabled) 323 spear_rtc_enable_interrupt(config); 324 else 325 spear_rtc_disable_interrupt(config); 326 327 return 0; 328 } 329 static struct rtc_class_ops spear_rtc_ops = { 330 .read_time = spear_rtc_read_time, 331 .set_time = spear_rtc_set_time, 332 .read_alarm = spear_rtc_read_alarm, 333 .set_alarm = spear_rtc_set_alarm, 334 }; 335 336 static int __devinit spear_rtc_probe(struct platform_device *pdev) 337 { 338 struct resource *res; 339 struct rtc_device *rtc; 340 struct spear_rtc_config *config; 341 unsigned int status = 0; 342 int irq; 343 344 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 345 if (!res) { 346 dev_err(&pdev->dev, "no resource defined\n"); 347 return -EBUSY; 348 } 349 if (!request_mem_region(res->start, resource_size(res), pdev->name)) { 350 dev_err(&pdev->dev, "rtc region already claimed\n"); 351 return -EBUSY; 352 } 353 354 config = kzalloc(sizeof(*config), GFP_KERNEL); 355 if (!config) { 356 dev_err(&pdev->dev, "out of memory\n"); 357 status = -ENOMEM; 358 goto err_release_region; 359 } 360 361 config->clk = clk_get(&pdev->dev, NULL); 362 if (IS_ERR(config->clk)) { 363 status = PTR_ERR(config->clk); 364 goto err_kfree; 365 } 366 367 status = clk_enable(config->clk); 368 if (status < 0) 369 goto err_clk_put; 370 371 config->ioaddr = ioremap(res->start, resource_size(res)); 372 if (!config->ioaddr) { 373 dev_err(&pdev->dev, "ioremap fail\n"); 374 status = -ENOMEM; 375 goto err_disable_clock; 376 } 377 378 spin_lock_init(&config->lock); 379 380 rtc = rtc_device_register(pdev->name, &pdev->dev, &spear_rtc_ops, 381 THIS_MODULE); 382 if (IS_ERR(rtc)) { 383 dev_err(&pdev->dev, "can't register RTC device, err %ld\n", 384 PTR_ERR(rtc)); 385 status = PTR_ERR(rtc); 386 goto err_iounmap; 387 } 388 389 platform_set_drvdata(pdev, rtc); 390 dev_set_drvdata(&rtc->dev, config); 391 392 /* alarm irqs */ 393 irq = platform_get_irq(pdev, 0); 394 if (irq < 0) { 395 dev_err(&pdev->dev, "no update irq?\n"); 396 status = irq; 397 goto err_clear_platdata; 398 } 399 400 status = request_irq(irq, spear_rtc_irq, 0, pdev->name, rtc); 401 if (status) { 402 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \ 403 claimed\n", irq); 404 goto err_clear_platdata; 405 } 406 407 if (!device_can_wakeup(&pdev->dev)) 408 device_init_wakeup(&pdev->dev, 1); 409 410 return 0; 411 412 err_clear_platdata: 413 platform_set_drvdata(pdev, NULL); 414 dev_set_drvdata(&rtc->dev, NULL); 415 rtc_device_unregister(rtc); 416 err_iounmap: 417 iounmap(config->ioaddr); 418 err_disable_clock: 419 clk_disable(config->clk); 420 err_clk_put: 421 clk_put(config->clk); 422 err_kfree: 423 kfree(config); 424 err_release_region: 425 release_mem_region(res->start, resource_size(res)); 426 427 return status; 428 } 429 430 static int __devexit spear_rtc_remove(struct platform_device *pdev) 431 { 432 struct rtc_device *rtc = platform_get_drvdata(pdev); 433 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 434 int irq; 435 struct resource *res; 436 437 /* leave rtc running, but disable irqs */ 438 spear_rtc_disable_interrupt(config); 439 device_init_wakeup(&pdev->dev, 0); 440 irq = platform_get_irq(pdev, 0); 441 if (irq) 442 free_irq(irq, pdev); 443 clk_disable(config->clk); 444 clk_put(config->clk); 445 iounmap(config->ioaddr); 446 kfree(config); 447 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 448 if (res) 449 release_mem_region(res->start, resource_size(res)); 450 platform_set_drvdata(pdev, NULL); 451 dev_set_drvdata(&rtc->dev, NULL); 452 rtc_device_unregister(rtc); 453 454 return 0; 455 } 456 457 #ifdef CONFIG_PM 458 459 static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state) 460 { 461 struct rtc_device *rtc = platform_get_drvdata(pdev); 462 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 463 int irq; 464 465 irq = platform_get_irq(pdev, 0); 466 if (device_may_wakeup(&pdev->dev)) 467 enable_irq_wake(irq); 468 else { 469 spear_rtc_disable_interrupt(config); 470 clk_disable(config->clk); 471 } 472 473 return 0; 474 } 475 476 static int spear_rtc_resume(struct platform_device *pdev) 477 { 478 struct rtc_device *rtc = platform_get_drvdata(pdev); 479 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 480 int irq; 481 482 irq = platform_get_irq(pdev, 0); 483 484 if (device_may_wakeup(&pdev->dev)) 485 disable_irq_wake(irq); 486 else { 487 clk_enable(config->clk); 488 spear_rtc_enable_interrupt(config); 489 } 490 491 return 0; 492 } 493 494 #else 495 #define spear_rtc_suspend NULL 496 #define spear_rtc_resume NULL 497 #endif 498 499 static void spear_rtc_shutdown(struct platform_device *pdev) 500 { 501 struct rtc_device *rtc = platform_get_drvdata(pdev); 502 struct spear_rtc_config *config = dev_get_drvdata(&rtc->dev); 503 504 spear_rtc_disable_interrupt(config); 505 clk_disable(config->clk); 506 } 507 508 static struct platform_driver spear_rtc_driver = { 509 .probe = spear_rtc_probe, 510 .remove = __devexit_p(spear_rtc_remove), 511 .suspend = spear_rtc_suspend, 512 .resume = spear_rtc_resume, 513 .shutdown = spear_rtc_shutdown, 514 .driver = { 515 .name = "rtc-spear", 516 }, 517 }; 518 519 module_platform_driver(spear_rtc_driver); 520 521 MODULE_ALIAS("platform:rtc-spear"); 522 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>"); 523 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); 524 MODULE_LICENSE("GPL"); 525