1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * drivers/rtc/rtc-pl031.c 4 * 5 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC 6 * 7 * Author: Deepak Saxena <dsaxena@plexity.net> 8 * 9 * Copyright 2006 (c) MontaVista Software, Inc. 10 * 11 * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com> 12 * Copyright 2010 (c) ST-Ericsson AB 13 */ 14 #include <linux/module.h> 15 #include <linux/rtc.h> 16 #include <linux/init.h> 17 #include <linux/interrupt.h> 18 #include <linux/amba/bus.h> 19 #include <linux/io.h> 20 #include <linux/bcd.h> 21 #include <linux/delay.h> 22 #include <linux/pm_wakeirq.h> 23 #include <linux/slab.h> 24 25 /* 26 * Register definitions 27 */ 28 #define RTC_DR 0x00 /* Data read register */ 29 #define RTC_MR 0x04 /* Match register */ 30 #define RTC_LR 0x08 /* Data load register */ 31 #define RTC_CR 0x0c /* Control register */ 32 #define RTC_IMSC 0x10 /* Interrupt mask and set register */ 33 #define RTC_RIS 0x14 /* Raw interrupt status register */ 34 #define RTC_MIS 0x18 /* Masked interrupt status register */ 35 #define RTC_ICR 0x1c /* Interrupt clear register */ 36 /* ST variants have additional timer functionality */ 37 #define RTC_TDR 0x20 /* Timer data read register */ 38 #define RTC_TLR 0x24 /* Timer data load register */ 39 #define RTC_TCR 0x28 /* Timer control register */ 40 #define RTC_YDR 0x30 /* Year data read register */ 41 #define RTC_YMR 0x34 /* Year match register */ 42 #define RTC_YLR 0x38 /* Year data load register */ 43 44 #define RTC_CR_EN (1 << 0) /* counter enable bit */ 45 #define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */ 46 47 #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */ 48 49 /* Common bit definitions for Interrupt status and control registers */ 50 #define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */ 51 #define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */ 52 53 /* Common bit definations for ST v2 for reading/writing time */ 54 #define RTC_SEC_SHIFT 0 55 #define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */ 56 #define RTC_MIN_SHIFT 6 57 #define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */ 58 #define RTC_HOUR_SHIFT 12 59 #define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */ 60 #define RTC_WDAY_SHIFT 17 61 #define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */ 62 #define RTC_MDAY_SHIFT 20 63 #define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */ 64 #define RTC_MON_SHIFT 25 65 #define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */ 66 67 #define RTC_TIMER_FREQ 32768 68 69 /** 70 * struct pl031_vendor_data - per-vendor variations 71 * @ops: the vendor-specific operations used on this silicon version 72 * @clockwatch: if this is an ST Microelectronics silicon version with a 73 * clockwatch function 74 * @st_weekday: if this is an ST Microelectronics silicon version that need 75 * the weekday fix 76 * @irqflags: special IRQ flags per variant 77 */ 78 struct pl031_vendor_data { 79 struct rtc_class_ops ops; 80 bool clockwatch; 81 bool st_weekday; 82 unsigned long irqflags; 83 }; 84 85 struct pl031_local { 86 struct pl031_vendor_data *vendor; 87 struct rtc_device *rtc; 88 void __iomem *base; 89 }; 90 91 static int pl031_alarm_irq_enable(struct device *dev, 92 unsigned int enabled) 93 { 94 struct pl031_local *ldata = dev_get_drvdata(dev); 95 unsigned long imsc; 96 97 /* Clear any pending alarm interrupts. */ 98 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 99 100 imsc = readl(ldata->base + RTC_IMSC); 101 102 if (enabled == 1) 103 writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC); 104 else 105 writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC); 106 107 return 0; 108 } 109 110 /* 111 * Convert Gregorian date to ST v2 RTC format. 112 */ 113 static int pl031_stv2_tm_to_time(struct device *dev, 114 struct rtc_time *tm, unsigned long *st_time, 115 unsigned long *bcd_year) 116 { 117 int year = tm->tm_year + 1900; 118 int wday = tm->tm_wday; 119 120 /* wday masking is not working in hardware so wday must be valid */ 121 if (wday < -1 || wday > 6) { 122 dev_err(dev, "invalid wday value %d\n", tm->tm_wday); 123 return -EINVAL; 124 } else if (wday == -1) { 125 /* wday is not provided, calculate it here */ 126 unsigned long time; 127 struct rtc_time calc_tm; 128 129 rtc_tm_to_time(tm, &time); 130 rtc_time_to_tm(time, &calc_tm); 131 wday = calc_tm.tm_wday; 132 } 133 134 *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8); 135 136 *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT) 137 | (tm->tm_mday << RTC_MDAY_SHIFT) 138 | ((wday + 1) << RTC_WDAY_SHIFT) 139 | (tm->tm_hour << RTC_HOUR_SHIFT) 140 | (tm->tm_min << RTC_MIN_SHIFT) 141 | (tm->tm_sec << RTC_SEC_SHIFT); 142 143 return 0; 144 } 145 146 /* 147 * Convert ST v2 RTC format to Gregorian date. 148 */ 149 static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year, 150 struct rtc_time *tm) 151 { 152 tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100); 153 tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1; 154 tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT); 155 tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1; 156 tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT); 157 tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT); 158 tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT); 159 160 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 161 tm->tm_year -= 1900; 162 163 return 0; 164 } 165 166 static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm) 167 { 168 struct pl031_local *ldata = dev_get_drvdata(dev); 169 170 pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR), 171 readl(ldata->base + RTC_YDR), tm); 172 173 return 0; 174 } 175 176 static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm) 177 { 178 unsigned long time; 179 unsigned long bcd_year; 180 struct pl031_local *ldata = dev_get_drvdata(dev); 181 int ret; 182 183 ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year); 184 if (ret == 0) { 185 writel(bcd_year, ldata->base + RTC_YLR); 186 writel(time, ldata->base + RTC_LR); 187 } 188 189 return ret; 190 } 191 192 static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 193 { 194 struct pl031_local *ldata = dev_get_drvdata(dev); 195 int ret; 196 197 ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR), 198 readl(ldata->base + RTC_YMR), &alarm->time); 199 200 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 201 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 202 203 return ret; 204 } 205 206 static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 207 { 208 struct pl031_local *ldata = dev_get_drvdata(dev); 209 unsigned long time; 210 unsigned long bcd_year; 211 int ret; 212 213 /* At the moment, we can only deal with non-wildcarded alarm times. */ 214 ret = rtc_valid_tm(&alarm->time); 215 if (ret == 0) { 216 ret = pl031_stv2_tm_to_time(dev, &alarm->time, 217 &time, &bcd_year); 218 if (ret == 0) { 219 writel(bcd_year, ldata->base + RTC_YMR); 220 writel(time, ldata->base + RTC_MR); 221 222 pl031_alarm_irq_enable(dev, alarm->enabled); 223 } 224 } 225 226 return ret; 227 } 228 229 static irqreturn_t pl031_interrupt(int irq, void *dev_id) 230 { 231 struct pl031_local *ldata = dev_id; 232 unsigned long rtcmis; 233 unsigned long events = 0; 234 235 rtcmis = readl(ldata->base + RTC_MIS); 236 if (rtcmis & RTC_BIT_AI) { 237 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 238 events |= (RTC_AF | RTC_IRQF); 239 rtc_update_irq(ldata->rtc, 1, events); 240 241 return IRQ_HANDLED; 242 } 243 244 return IRQ_NONE; 245 } 246 247 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 248 { 249 struct pl031_local *ldata = dev_get_drvdata(dev); 250 251 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 252 253 return 0; 254 } 255 256 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 257 { 258 unsigned long time; 259 struct pl031_local *ldata = dev_get_drvdata(dev); 260 int ret; 261 262 ret = rtc_tm_to_time(tm, &time); 263 264 if (ret == 0) 265 writel(time, ldata->base + RTC_LR); 266 267 return ret; 268 } 269 270 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 271 { 272 struct pl031_local *ldata = dev_get_drvdata(dev); 273 274 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 275 276 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 277 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 278 279 return 0; 280 } 281 282 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 283 { 284 struct pl031_local *ldata = dev_get_drvdata(dev); 285 unsigned long time; 286 int ret; 287 288 /* At the moment, we can only deal with non-wildcarded alarm times. */ 289 ret = rtc_valid_tm(&alarm->time); 290 if (ret == 0) { 291 ret = rtc_tm_to_time(&alarm->time, &time); 292 if (ret == 0) { 293 writel(time, ldata->base + RTC_MR); 294 pl031_alarm_irq_enable(dev, alarm->enabled); 295 } 296 } 297 298 return ret; 299 } 300 301 static int pl031_remove(struct amba_device *adev) 302 { 303 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 304 305 dev_pm_clear_wake_irq(&adev->dev); 306 device_init_wakeup(&adev->dev, false); 307 if (adev->irq[0]) 308 free_irq(adev->irq[0], ldata); 309 amba_release_regions(adev); 310 311 return 0; 312 } 313 314 static int pl031_probe(struct amba_device *adev, const struct amba_id *id) 315 { 316 int ret; 317 struct pl031_local *ldata; 318 struct pl031_vendor_data *vendor = id->data; 319 struct rtc_class_ops *ops; 320 unsigned long time, data; 321 322 ret = amba_request_regions(adev, NULL); 323 if (ret) 324 goto err_req; 325 326 ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local), 327 GFP_KERNEL); 328 ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops), 329 GFP_KERNEL); 330 if (!ldata || !ops) { 331 ret = -ENOMEM; 332 goto out; 333 } 334 335 ldata->vendor = vendor; 336 ldata->base = devm_ioremap(&adev->dev, adev->res.start, 337 resource_size(&adev->res)); 338 if (!ldata->base) { 339 ret = -ENOMEM; 340 goto out; 341 } 342 343 amba_set_drvdata(adev, ldata); 344 345 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev)); 346 dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); 347 348 data = readl(ldata->base + RTC_CR); 349 /* Enable the clockwatch on ST Variants */ 350 if (vendor->clockwatch) 351 data |= RTC_CR_CWEN; 352 else 353 data |= RTC_CR_EN; 354 writel(data, ldata->base + RTC_CR); 355 356 /* 357 * On ST PL031 variants, the RTC reset value does not provide correct 358 * weekday for 2000-01-01. Correct the erroneous sunday to saturday. 359 */ 360 if (vendor->st_weekday) { 361 if (readl(ldata->base + RTC_YDR) == 0x2000) { 362 time = readl(ldata->base + RTC_DR); 363 if ((time & 364 (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) 365 == 0x02120000) { 366 time = time | (0x7 << RTC_WDAY_SHIFT); 367 writel(0x2000, ldata->base + RTC_YLR); 368 writel(time, ldata->base + RTC_LR); 369 } 370 } 371 } 372 373 if (!adev->irq[0]) { 374 /* When there's no interrupt, no point in exposing the alarm */ 375 ops->read_alarm = NULL; 376 ops->set_alarm = NULL; 377 ops->alarm_irq_enable = NULL; 378 } 379 380 device_init_wakeup(&adev->dev, true); 381 ldata->rtc = devm_rtc_allocate_device(&adev->dev); 382 if (IS_ERR(ldata->rtc)) 383 return PTR_ERR(ldata->rtc); 384 385 ldata->rtc->ops = ops; 386 387 ret = rtc_register_device(ldata->rtc); 388 if (ret) 389 goto out; 390 391 if (adev->irq[0]) { 392 ret = request_irq(adev->irq[0], pl031_interrupt, 393 vendor->irqflags, "rtc-pl031", ldata); 394 if (ret) 395 goto out; 396 dev_pm_set_wake_irq(&adev->dev, adev->irq[0]); 397 } 398 return 0; 399 400 out: 401 amba_release_regions(adev); 402 err_req: 403 404 return ret; 405 } 406 407 /* Operations for the original ARM version */ 408 static struct pl031_vendor_data arm_pl031 = { 409 .ops = { 410 .read_time = pl031_read_time, 411 .set_time = pl031_set_time, 412 .read_alarm = pl031_read_alarm, 413 .set_alarm = pl031_set_alarm, 414 .alarm_irq_enable = pl031_alarm_irq_enable, 415 }, 416 }; 417 418 /* The First ST derivative */ 419 static struct pl031_vendor_data stv1_pl031 = { 420 .ops = { 421 .read_time = pl031_read_time, 422 .set_time = pl031_set_time, 423 .read_alarm = pl031_read_alarm, 424 .set_alarm = pl031_set_alarm, 425 .alarm_irq_enable = pl031_alarm_irq_enable, 426 }, 427 .clockwatch = true, 428 .st_weekday = true, 429 }; 430 431 /* And the second ST derivative */ 432 static struct pl031_vendor_data stv2_pl031 = { 433 .ops = { 434 .read_time = pl031_stv2_read_time, 435 .set_time = pl031_stv2_set_time, 436 .read_alarm = pl031_stv2_read_alarm, 437 .set_alarm = pl031_stv2_set_alarm, 438 .alarm_irq_enable = pl031_alarm_irq_enable, 439 }, 440 .clockwatch = true, 441 .st_weekday = true, 442 /* 443 * This variant shares the IRQ with another block and must not 444 * suspend that IRQ line. 445 * TODO check if it shares with IRQF_NO_SUSPEND user, else we can 446 * remove IRQF_COND_SUSPEND 447 */ 448 .irqflags = IRQF_SHARED | IRQF_COND_SUSPEND, 449 }; 450 451 static const struct amba_id pl031_ids[] = { 452 { 453 .id = 0x00041031, 454 .mask = 0x000fffff, 455 .data = &arm_pl031, 456 }, 457 /* ST Micro variants */ 458 { 459 .id = 0x00180031, 460 .mask = 0x00ffffff, 461 .data = &stv1_pl031, 462 }, 463 { 464 .id = 0x00280031, 465 .mask = 0x00ffffff, 466 .data = &stv2_pl031, 467 }, 468 {0, 0}, 469 }; 470 471 MODULE_DEVICE_TABLE(amba, pl031_ids); 472 473 static struct amba_driver pl031_driver = { 474 .drv = { 475 .name = "rtc-pl031", 476 }, 477 .id_table = pl031_ids, 478 .probe = pl031_probe, 479 .remove = pl031_remove, 480 }; 481 482 module_amba_driver(pl031_driver); 483 484 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); 485 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 486 MODULE_LICENSE("GPL"); 487