1 /* 2 * drivers/rtc/rtc-pl031.c 3 * 4 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC 5 * 6 * Author: Deepak Saxena <dsaxena@plexity.net> 7 * 8 * Copyright 2006 (c) MontaVista Software, Inc. 9 * 10 * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com> 11 * Copyright 2010 (c) ST-Ericsson AB 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 */ 18 #include <linux/module.h> 19 #include <linux/rtc.h> 20 #include <linux/init.h> 21 #include <linux/interrupt.h> 22 #include <linux/amba/bus.h> 23 #include <linux/io.h> 24 #include <linux/bcd.h> 25 #include <linux/delay.h> 26 #include <linux/pm_wakeirq.h> 27 #include <linux/slab.h> 28 29 /* 30 * Register definitions 31 */ 32 #define RTC_DR 0x00 /* Data read register */ 33 #define RTC_MR 0x04 /* Match register */ 34 #define RTC_LR 0x08 /* Data load register */ 35 #define RTC_CR 0x0c /* Control register */ 36 #define RTC_IMSC 0x10 /* Interrupt mask and set register */ 37 #define RTC_RIS 0x14 /* Raw interrupt status register */ 38 #define RTC_MIS 0x18 /* Masked interrupt status register */ 39 #define RTC_ICR 0x1c /* Interrupt clear register */ 40 /* ST variants have additional timer functionality */ 41 #define RTC_TDR 0x20 /* Timer data read register */ 42 #define RTC_TLR 0x24 /* Timer data load register */ 43 #define RTC_TCR 0x28 /* Timer control register */ 44 #define RTC_YDR 0x30 /* Year data read register */ 45 #define RTC_YMR 0x34 /* Year match register */ 46 #define RTC_YLR 0x38 /* Year data load register */ 47 48 #define RTC_CR_EN (1 << 0) /* counter enable bit */ 49 #define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */ 50 51 #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */ 52 53 /* Common bit definitions for Interrupt status and control registers */ 54 #define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */ 55 #define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */ 56 57 /* Common bit definations for ST v2 for reading/writing time */ 58 #define RTC_SEC_SHIFT 0 59 #define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */ 60 #define RTC_MIN_SHIFT 6 61 #define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */ 62 #define RTC_HOUR_SHIFT 12 63 #define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */ 64 #define RTC_WDAY_SHIFT 17 65 #define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */ 66 #define RTC_MDAY_SHIFT 20 67 #define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */ 68 #define RTC_MON_SHIFT 25 69 #define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */ 70 71 #define RTC_TIMER_FREQ 32768 72 73 /** 74 * struct pl031_vendor_data - per-vendor variations 75 * @ops: the vendor-specific operations used on this silicon version 76 * @clockwatch: if this is an ST Microelectronics silicon version with a 77 * clockwatch function 78 * @st_weekday: if this is an ST Microelectronics silicon version that need 79 * the weekday fix 80 * @irqflags: special IRQ flags per variant 81 */ 82 struct pl031_vendor_data { 83 struct rtc_class_ops ops; 84 bool clockwatch; 85 bool st_weekday; 86 unsigned long irqflags; 87 }; 88 89 struct pl031_local { 90 struct pl031_vendor_data *vendor; 91 struct rtc_device *rtc; 92 void __iomem *base; 93 }; 94 95 static int pl031_alarm_irq_enable(struct device *dev, 96 unsigned int enabled) 97 { 98 struct pl031_local *ldata = dev_get_drvdata(dev); 99 unsigned long imsc; 100 101 /* Clear any pending alarm interrupts. */ 102 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 103 104 imsc = readl(ldata->base + RTC_IMSC); 105 106 if (enabled == 1) 107 writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC); 108 else 109 writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC); 110 111 return 0; 112 } 113 114 /* 115 * Convert Gregorian date to ST v2 RTC format. 116 */ 117 static int pl031_stv2_tm_to_time(struct device *dev, 118 struct rtc_time *tm, unsigned long *st_time, 119 unsigned long *bcd_year) 120 { 121 int year = tm->tm_year + 1900; 122 int wday = tm->tm_wday; 123 124 /* wday masking is not working in hardware so wday must be valid */ 125 if (wday < -1 || wday > 6) { 126 dev_err(dev, "invalid wday value %d\n", tm->tm_wday); 127 return -EINVAL; 128 } else if (wday == -1) { 129 /* wday is not provided, calculate it here */ 130 unsigned long time; 131 struct rtc_time calc_tm; 132 133 rtc_tm_to_time(tm, &time); 134 rtc_time_to_tm(time, &calc_tm); 135 wday = calc_tm.tm_wday; 136 } 137 138 *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8); 139 140 *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT) 141 | (tm->tm_mday << RTC_MDAY_SHIFT) 142 | ((wday + 1) << RTC_WDAY_SHIFT) 143 | (tm->tm_hour << RTC_HOUR_SHIFT) 144 | (tm->tm_min << RTC_MIN_SHIFT) 145 | (tm->tm_sec << RTC_SEC_SHIFT); 146 147 return 0; 148 } 149 150 /* 151 * Convert ST v2 RTC format to Gregorian date. 152 */ 153 static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year, 154 struct rtc_time *tm) 155 { 156 tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100); 157 tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1; 158 tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT); 159 tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1; 160 tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT); 161 tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT); 162 tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT); 163 164 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 165 tm->tm_year -= 1900; 166 167 return 0; 168 } 169 170 static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm) 171 { 172 struct pl031_local *ldata = dev_get_drvdata(dev); 173 174 pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR), 175 readl(ldata->base + RTC_YDR), tm); 176 177 return 0; 178 } 179 180 static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm) 181 { 182 unsigned long time; 183 unsigned long bcd_year; 184 struct pl031_local *ldata = dev_get_drvdata(dev); 185 int ret; 186 187 ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year); 188 if (ret == 0) { 189 writel(bcd_year, ldata->base + RTC_YLR); 190 writel(time, ldata->base + RTC_LR); 191 } 192 193 return ret; 194 } 195 196 static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 197 { 198 struct pl031_local *ldata = dev_get_drvdata(dev); 199 int ret; 200 201 ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR), 202 readl(ldata->base + RTC_YMR), &alarm->time); 203 204 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 205 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 206 207 return ret; 208 } 209 210 static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 211 { 212 struct pl031_local *ldata = dev_get_drvdata(dev); 213 unsigned long time; 214 unsigned long bcd_year; 215 int ret; 216 217 /* At the moment, we can only deal with non-wildcarded alarm times. */ 218 ret = rtc_valid_tm(&alarm->time); 219 if (ret == 0) { 220 ret = pl031_stv2_tm_to_time(dev, &alarm->time, 221 &time, &bcd_year); 222 if (ret == 0) { 223 writel(bcd_year, ldata->base + RTC_YMR); 224 writel(time, ldata->base + RTC_MR); 225 226 pl031_alarm_irq_enable(dev, alarm->enabled); 227 } 228 } 229 230 return ret; 231 } 232 233 static irqreturn_t pl031_interrupt(int irq, void *dev_id) 234 { 235 struct pl031_local *ldata = dev_id; 236 unsigned long rtcmis; 237 unsigned long events = 0; 238 239 rtcmis = readl(ldata->base + RTC_MIS); 240 if (rtcmis & RTC_BIT_AI) { 241 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 242 events |= (RTC_AF | RTC_IRQF); 243 rtc_update_irq(ldata->rtc, 1, events); 244 245 return IRQ_HANDLED; 246 } 247 248 return IRQ_NONE; 249 } 250 251 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 252 { 253 struct pl031_local *ldata = dev_get_drvdata(dev); 254 255 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 256 257 return 0; 258 } 259 260 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 261 { 262 unsigned long time; 263 struct pl031_local *ldata = dev_get_drvdata(dev); 264 int ret; 265 266 ret = rtc_tm_to_time(tm, &time); 267 268 if (ret == 0) 269 writel(time, ldata->base + RTC_LR); 270 271 return ret; 272 } 273 274 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 275 { 276 struct pl031_local *ldata = dev_get_drvdata(dev); 277 278 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 279 280 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 281 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 282 283 return 0; 284 } 285 286 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 287 { 288 struct pl031_local *ldata = dev_get_drvdata(dev); 289 unsigned long time; 290 int ret; 291 292 /* At the moment, we can only deal with non-wildcarded alarm times. */ 293 ret = rtc_valid_tm(&alarm->time); 294 if (ret == 0) { 295 ret = rtc_tm_to_time(&alarm->time, &time); 296 if (ret == 0) { 297 writel(time, ldata->base + RTC_MR); 298 pl031_alarm_irq_enable(dev, alarm->enabled); 299 } 300 } 301 302 return ret; 303 } 304 305 static int pl031_remove(struct amba_device *adev) 306 { 307 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 308 309 dev_pm_clear_wake_irq(&adev->dev); 310 device_init_wakeup(&adev->dev, false); 311 if (adev->irq[0]) 312 free_irq(adev->irq[0], ldata); 313 amba_release_regions(adev); 314 315 return 0; 316 } 317 318 static int pl031_probe(struct amba_device *adev, const struct amba_id *id) 319 { 320 int ret; 321 struct pl031_local *ldata; 322 struct pl031_vendor_data *vendor = id->data; 323 struct rtc_class_ops *ops; 324 unsigned long time, data; 325 326 ret = amba_request_regions(adev, NULL); 327 if (ret) 328 goto err_req; 329 330 ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local), 331 GFP_KERNEL); 332 ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops), 333 GFP_KERNEL); 334 if (!ldata || !ops) { 335 ret = -ENOMEM; 336 goto out; 337 } 338 339 ldata->vendor = vendor; 340 ldata->base = devm_ioremap(&adev->dev, adev->res.start, 341 resource_size(&adev->res)); 342 if (!ldata->base) { 343 ret = -ENOMEM; 344 goto out; 345 } 346 347 amba_set_drvdata(adev, ldata); 348 349 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev)); 350 dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); 351 352 data = readl(ldata->base + RTC_CR); 353 /* Enable the clockwatch on ST Variants */ 354 if (vendor->clockwatch) 355 data |= RTC_CR_CWEN; 356 else 357 data |= RTC_CR_EN; 358 writel(data, ldata->base + RTC_CR); 359 360 /* 361 * On ST PL031 variants, the RTC reset value does not provide correct 362 * weekday for 2000-01-01. Correct the erroneous sunday to saturday. 363 */ 364 if (vendor->st_weekday) { 365 if (readl(ldata->base + RTC_YDR) == 0x2000) { 366 time = readl(ldata->base + RTC_DR); 367 if ((time & 368 (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) 369 == 0x02120000) { 370 time = time | (0x7 << RTC_WDAY_SHIFT); 371 writel(0x2000, ldata->base + RTC_YLR); 372 writel(time, ldata->base + RTC_LR); 373 } 374 } 375 } 376 377 if (!adev->irq[0]) { 378 /* When there's no interrupt, no point in exposing the alarm */ 379 ops->read_alarm = NULL; 380 ops->set_alarm = NULL; 381 ops->alarm_irq_enable = NULL; 382 } 383 384 device_init_wakeup(&adev->dev, true); 385 ldata->rtc = devm_rtc_allocate_device(&adev->dev); 386 if (IS_ERR(ldata->rtc)) 387 return PTR_ERR(ldata->rtc); 388 389 ldata->rtc->ops = ops; 390 391 ret = rtc_register_device(ldata->rtc); 392 if (ret) 393 goto out; 394 395 if (adev->irq[0]) { 396 ret = request_irq(adev->irq[0], pl031_interrupt, 397 vendor->irqflags, "rtc-pl031", ldata); 398 if (ret) 399 goto out; 400 dev_pm_set_wake_irq(&adev->dev, adev->irq[0]); 401 } 402 return 0; 403 404 out: 405 amba_release_regions(adev); 406 err_req: 407 408 return ret; 409 } 410 411 /* Operations for the original ARM version */ 412 static struct pl031_vendor_data arm_pl031 = { 413 .ops = { 414 .read_time = pl031_read_time, 415 .set_time = pl031_set_time, 416 .read_alarm = pl031_read_alarm, 417 .set_alarm = pl031_set_alarm, 418 .alarm_irq_enable = pl031_alarm_irq_enable, 419 }, 420 }; 421 422 /* The First ST derivative */ 423 static struct pl031_vendor_data stv1_pl031 = { 424 .ops = { 425 .read_time = pl031_read_time, 426 .set_time = pl031_set_time, 427 .read_alarm = pl031_read_alarm, 428 .set_alarm = pl031_set_alarm, 429 .alarm_irq_enable = pl031_alarm_irq_enable, 430 }, 431 .clockwatch = true, 432 .st_weekday = true, 433 }; 434 435 /* And the second ST derivative */ 436 static struct pl031_vendor_data stv2_pl031 = { 437 .ops = { 438 .read_time = pl031_stv2_read_time, 439 .set_time = pl031_stv2_set_time, 440 .read_alarm = pl031_stv2_read_alarm, 441 .set_alarm = pl031_stv2_set_alarm, 442 .alarm_irq_enable = pl031_alarm_irq_enable, 443 }, 444 .clockwatch = true, 445 .st_weekday = true, 446 /* 447 * This variant shares the IRQ with another block and must not 448 * suspend that IRQ line. 449 * TODO check if it shares with IRQF_NO_SUSPEND user, else we can 450 * remove IRQF_COND_SUSPEND 451 */ 452 .irqflags = IRQF_SHARED | IRQF_COND_SUSPEND, 453 }; 454 455 static const struct amba_id pl031_ids[] = { 456 { 457 .id = 0x00041031, 458 .mask = 0x000fffff, 459 .data = &arm_pl031, 460 }, 461 /* ST Micro variants */ 462 { 463 .id = 0x00180031, 464 .mask = 0x00ffffff, 465 .data = &stv1_pl031, 466 }, 467 { 468 .id = 0x00280031, 469 .mask = 0x00ffffff, 470 .data = &stv2_pl031, 471 }, 472 {0, 0}, 473 }; 474 475 MODULE_DEVICE_TABLE(amba, pl031_ids); 476 477 static struct amba_driver pl031_driver = { 478 .drv = { 479 .name = "rtc-pl031", 480 }, 481 .id_table = pl031_ids, 482 .probe = pl031_probe, 483 .remove = pl031_remove, 484 }; 485 486 module_amba_driver(pl031_driver); 487 488 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); 489 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 490 MODULE_LICENSE("GPL"); 491