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/of.h> 20 #include <linux/platform_device.h> 21 #include <linux/rtc.h> 22 #include <linux/slab.h> 23 #include <linux/spinlock.h> 24 25 /* RTC registers */ 26 #define TIME_REG 0x00 27 #define DATE_REG 0x04 28 #define ALARM_TIME_REG 0x08 29 #define ALARM_DATE_REG 0x0C 30 #define CTRL_REG 0x10 31 #define STATUS_REG 0x14 32 33 /* TIME_REG & ALARM_TIME_REG */ 34 #define SECONDS_UNITS (0xf<<0) /* seconds units position */ 35 #define SECONDS_TENS (0x7<<4) /* seconds tens position */ 36 #define MINUTES_UNITS (0xf<<8) /* minutes units position */ 37 #define MINUTES_TENS (0x7<<12) /* minutes tens position */ 38 #define HOURS_UNITS (0xf<<16) /* hours units position */ 39 #define HOURS_TENS (0x3<<20) /* hours tens position */ 40 41 /* DATE_REG & ALARM_DATE_REG */ 42 #define DAYS_UNITS (0xf<<0) /* days units position */ 43 #define DAYS_TENS (0x3<<4) /* days tens position */ 44 #define MONTHS_UNITS (0xf<<8) /* months units position */ 45 #define MONTHS_TENS (0x1<<12) /* months tens position */ 46 #define YEARS_UNITS (0xf<<16) /* years units position */ 47 #define YEARS_TENS (0xf<<20) /* years tens position */ 48 #define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */ 49 #define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */ 50 51 /* MASK SHIFT TIME_REG & ALARM_TIME_REG*/ 52 #define SECOND_SHIFT 0x00 /* seconds units */ 53 #define MINUTE_SHIFT 0x08 /* minutes units position */ 54 #define HOUR_SHIFT 0x10 /* hours units position */ 55 #define MDAY_SHIFT 0x00 /* Month day shift */ 56 #define MONTH_SHIFT 0x08 /* Month shift */ 57 #define YEAR_SHIFT 0x10 /* Year shift */ 58 59 #define SECOND_MASK 0x7F 60 #define MIN_MASK 0x7F 61 #define HOUR_MASK 0x3F 62 #define DAY_MASK 0x3F 63 #define MONTH_MASK 0x7F 64 #define YEAR_MASK 0xFFFF 65 66 /* date reg equal to time reg, for debug only */ 67 #define TIME_BYP (1<<9) 68 #define INT_ENABLE (1<<31) /* interrupt enable */ 69 70 /* STATUS_REG */ 71 #define CLK_UNCONNECTED (1<<0) 72 #define PEND_WR_TIME (1<<2) 73 #define PEND_WR_DATE (1<<3) 74 #define LOST_WR_TIME (1<<4) 75 #define LOST_WR_DATE (1<<5) 76 #define RTC_INT_MASK (1<<31) 77 #define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE) 78 #define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE) 79 80 struct spear_rtc_config { 81 struct rtc_device *rtc; 82 struct clk *clk; 83 spinlock_t lock; 84 void __iomem *ioaddr; 85 unsigned int irq_wake; 86 }; 87 88 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config) 89 { 90 unsigned int val; 91 unsigned long flags; 92 93 spin_lock_irqsave(&config->lock, flags); 94 val = readl(config->ioaddr + STATUS_REG); 95 val |= RTC_INT_MASK; 96 writel(val, config->ioaddr + STATUS_REG); 97 spin_unlock_irqrestore(&config->lock, flags); 98 } 99 100 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config) 101 { 102 unsigned int val; 103 104 val = readl(config->ioaddr + CTRL_REG); 105 if (!(val & INT_ENABLE)) { 106 spear_rtc_clear_interrupt(config); 107 val |= INT_ENABLE; 108 writel(val, config->ioaddr + CTRL_REG); 109 } 110 } 111 112 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config) 113 { 114 unsigned int val; 115 116 val = readl(config->ioaddr + CTRL_REG); 117 if (val & INT_ENABLE) { 118 val &= ~INT_ENABLE; 119 writel(val, config->ioaddr + CTRL_REG); 120 } 121 } 122 123 static inline int is_write_complete(struct spear_rtc_config *config) 124 { 125 int ret = 0; 126 unsigned long flags; 127 128 spin_lock_irqsave(&config->lock, flags); 129 if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL) 130 ret = -EIO; 131 spin_unlock_irqrestore(&config->lock, flags); 132 133 return ret; 134 } 135 136 static void rtc_wait_not_busy(struct spear_rtc_config *config) 137 { 138 int status, count = 0; 139 unsigned long flags; 140 141 /* Assuming BUSY may stay active for 80 msec) */ 142 for (count = 0; count < 80; count++) { 143 spin_lock_irqsave(&config->lock, flags); 144 status = readl(config->ioaddr + STATUS_REG); 145 spin_unlock_irqrestore(&config->lock, flags); 146 if ((status & STATUS_BUSY) == 0) 147 break; 148 /* check status busy, after each msec */ 149 msleep(1); 150 } 151 } 152 153 static irqreturn_t spear_rtc_irq(int irq, void *dev_id) 154 { 155 struct spear_rtc_config *config = dev_id; 156 unsigned long flags, events = 0; 157 unsigned int irq_data; 158 159 spin_lock_irqsave(&config->lock, flags); 160 irq_data = readl(config->ioaddr + STATUS_REG); 161 spin_unlock_irqrestore(&config->lock, flags); 162 163 if ((irq_data & RTC_INT_MASK)) { 164 spear_rtc_clear_interrupt(config); 165 events = RTC_IRQF | RTC_AF; 166 rtc_update_irq(config->rtc, 1, events); 167 return IRQ_HANDLED; 168 } else 169 return IRQ_NONE; 170 171 } 172 173 static void tm2bcd(struct rtc_time *tm) 174 { 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 } 182 183 static void bcd2tm(struct rtc_time *tm) 184 { 185 tm->tm_sec = bcd2bin(tm->tm_sec); 186 tm->tm_min = bcd2bin(tm->tm_min); 187 tm->tm_hour = bcd2bin(tm->tm_hour); 188 tm->tm_mday = bcd2bin(tm->tm_mday); 189 tm->tm_mon = bcd2bin(tm->tm_mon) - 1; 190 /* epoch == 1900 */ 191 tm->tm_year = bcd2bin(tm->tm_year); 192 } 193 194 /* 195 * spear_rtc_read_time - set the time 196 * @dev: rtc device in use 197 * @tm: holds date and time 198 * 199 * This function read time and date. On success it will return 0 200 * otherwise -ve error is returned. 201 */ 202 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm) 203 { 204 struct spear_rtc_config *config = dev_get_drvdata(dev); 205 unsigned int time, date; 206 207 /* we don't report wday/yday/isdst ... */ 208 rtc_wait_not_busy(config); 209 210 time = readl(config->ioaddr + TIME_REG); 211 date = readl(config->ioaddr + DATE_REG); 212 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; 213 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; 214 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; 215 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; 216 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; 217 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; 218 219 bcd2tm(tm); 220 return 0; 221 } 222 223 /* 224 * spear_rtc_set_time - set the time 225 * @dev: rtc device in use 226 * @tm: holds date and time 227 * 228 * This function set time and date. On success it will return 0 229 * otherwise -ve error is returned. 230 */ 231 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm) 232 { 233 struct spear_rtc_config *config = dev_get_drvdata(dev); 234 unsigned int time, date; 235 236 tm2bcd(tm); 237 238 rtc_wait_not_busy(config); 239 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) | 240 (tm->tm_hour << HOUR_SHIFT); 241 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) | 242 (tm->tm_year << YEAR_SHIFT); 243 writel(time, config->ioaddr + TIME_REG); 244 writel(date, config->ioaddr + DATE_REG); 245 246 return is_write_complete(config); 247 } 248 249 /* 250 * spear_rtc_read_alarm - read the alarm time 251 * @dev: rtc device in use 252 * @alm: holds alarm date and time 253 * 254 * This function read alarm time and date. On success it will return 0 255 * otherwise -ve error is returned. 256 */ 257 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 258 { 259 struct spear_rtc_config *config = dev_get_drvdata(dev); 260 unsigned int time, date; 261 262 rtc_wait_not_busy(config); 263 264 time = readl(config->ioaddr + ALARM_TIME_REG); 265 date = readl(config->ioaddr + ALARM_DATE_REG); 266 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; 267 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; 268 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; 269 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; 270 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; 271 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; 272 273 bcd2tm(&alm->time); 274 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE; 275 276 return 0; 277 } 278 279 /* 280 * spear_rtc_set_alarm - set the alarm time 281 * @dev: rtc device in use 282 * @alm: holds alarm date and time 283 * 284 * This function set alarm time and date. On success it will return 0 285 * otherwise -ve error is returned. 286 */ 287 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 288 { 289 struct spear_rtc_config *config = dev_get_drvdata(dev); 290 unsigned int time, date; 291 int err; 292 293 tm2bcd(&alm->time); 294 295 rtc_wait_not_busy(config); 296 297 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min << 298 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT); 299 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon << 300 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT); 301 302 writel(time, config->ioaddr + ALARM_TIME_REG); 303 writel(date, config->ioaddr + ALARM_DATE_REG); 304 err = is_write_complete(config); 305 if (err < 0) 306 return err; 307 308 if (alm->enabled) 309 spear_rtc_enable_interrupt(config); 310 else 311 spear_rtc_disable_interrupt(config); 312 313 return 0; 314 } 315 316 static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled) 317 { 318 struct spear_rtc_config *config = dev_get_drvdata(dev); 319 int ret = 0; 320 321 spear_rtc_clear_interrupt(config); 322 323 switch (enabled) { 324 case 0: 325 /* alarm off */ 326 spear_rtc_disable_interrupt(config); 327 break; 328 case 1: 329 /* alarm on */ 330 spear_rtc_enable_interrupt(config); 331 break; 332 default: 333 ret = -EINVAL; 334 break; 335 } 336 337 return ret; 338 } 339 340 static const struct rtc_class_ops spear_rtc_ops = { 341 .read_time = spear_rtc_read_time, 342 .set_time = spear_rtc_set_time, 343 .read_alarm = spear_rtc_read_alarm, 344 .set_alarm = spear_rtc_set_alarm, 345 .alarm_irq_enable = spear_alarm_irq_enable, 346 }; 347 348 static int spear_rtc_probe(struct platform_device *pdev) 349 { 350 struct spear_rtc_config *config; 351 int status = 0; 352 int irq; 353 354 config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL); 355 if (!config) 356 return -ENOMEM; 357 358 /* alarm irqs */ 359 irq = platform_get_irq(pdev, 0); 360 if (irq < 0) 361 return irq; 362 363 status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name, 364 config); 365 if (status) { 366 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n", 367 irq); 368 return status; 369 } 370 371 config->ioaddr = devm_platform_ioremap_resource(pdev, 0); 372 if (IS_ERR(config->ioaddr)) 373 return PTR_ERR(config->ioaddr); 374 375 config->clk = devm_clk_get(&pdev->dev, NULL); 376 if (IS_ERR(config->clk)) 377 return PTR_ERR(config->clk); 378 379 status = clk_prepare_enable(config->clk); 380 if (status < 0) 381 return status; 382 383 spin_lock_init(&config->lock); 384 platform_set_drvdata(pdev, config); 385 386 config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 387 &spear_rtc_ops, THIS_MODULE); 388 if (IS_ERR(config->rtc)) { 389 dev_err(&pdev->dev, "can't register RTC device, err %ld\n", 390 PTR_ERR(config->rtc)); 391 status = PTR_ERR(config->rtc); 392 goto err_disable_clock; 393 } 394 395 config->rtc->uie_unsupported = 1; 396 397 if (!device_can_wakeup(&pdev->dev)) 398 device_init_wakeup(&pdev->dev, 1); 399 400 return 0; 401 402 err_disable_clock: 403 clk_disable_unprepare(config->clk); 404 405 return status; 406 } 407 408 static int spear_rtc_remove(struct platform_device *pdev) 409 { 410 struct spear_rtc_config *config = platform_get_drvdata(pdev); 411 412 spear_rtc_disable_interrupt(config); 413 clk_disable_unprepare(config->clk); 414 device_init_wakeup(&pdev->dev, 0); 415 416 return 0; 417 } 418 419 #ifdef CONFIG_PM_SLEEP 420 static int spear_rtc_suspend(struct device *dev) 421 { 422 struct platform_device *pdev = to_platform_device(dev); 423 struct spear_rtc_config *config = platform_get_drvdata(pdev); 424 int irq; 425 426 irq = platform_get_irq(pdev, 0); 427 if (device_may_wakeup(&pdev->dev)) { 428 if (!enable_irq_wake(irq)) 429 config->irq_wake = 1; 430 } else { 431 spear_rtc_disable_interrupt(config); 432 clk_disable(config->clk); 433 } 434 435 return 0; 436 } 437 438 static int spear_rtc_resume(struct device *dev) 439 { 440 struct platform_device *pdev = to_platform_device(dev); 441 struct spear_rtc_config *config = platform_get_drvdata(pdev); 442 int irq; 443 444 irq = platform_get_irq(pdev, 0); 445 446 if (device_may_wakeup(&pdev->dev)) { 447 if (config->irq_wake) { 448 disable_irq_wake(irq); 449 config->irq_wake = 0; 450 } 451 } else { 452 clk_enable(config->clk); 453 spear_rtc_enable_interrupt(config); 454 } 455 456 return 0; 457 } 458 #endif 459 460 static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume); 461 462 static void spear_rtc_shutdown(struct platform_device *pdev) 463 { 464 struct spear_rtc_config *config = platform_get_drvdata(pdev); 465 466 spear_rtc_disable_interrupt(config); 467 clk_disable(config->clk); 468 } 469 470 #ifdef CONFIG_OF 471 static const struct of_device_id spear_rtc_id_table[] = { 472 { .compatible = "st,spear600-rtc" }, 473 {} 474 }; 475 MODULE_DEVICE_TABLE(of, spear_rtc_id_table); 476 #endif 477 478 static struct platform_driver spear_rtc_driver = { 479 .probe = spear_rtc_probe, 480 .remove = spear_rtc_remove, 481 .shutdown = spear_rtc_shutdown, 482 .driver = { 483 .name = "rtc-spear", 484 .pm = &spear_rtc_pm_ops, 485 .of_match_table = of_match_ptr(spear_rtc_id_table), 486 }, 487 }; 488 489 module_platform_driver(spear_rtc_driver); 490 491 MODULE_ALIAS("platform:rtc-spear"); 492 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>"); 493 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); 494 MODULE_LICENSE("GPL"); 495