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 * @range_min: minimum date/time supported by the RTC 78 * @range_max: maximum date/time supported by the RTC 79 */ 80 struct pl031_vendor_data { 81 struct rtc_class_ops ops; 82 bool clockwatch; 83 bool st_weekday; 84 unsigned long irqflags; 85 time64_t range_min; 86 timeu64_t range_max; 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 struct rtc_time calc_tm; 131 132 rtc_time64_to_tm(rtc_tm_to_time64(tm), &calc_tm); 133 wday = calc_tm.tm_wday; 134 } 135 136 *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8); 137 138 *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT) 139 | (tm->tm_mday << RTC_MDAY_SHIFT) 140 | ((wday + 1) << RTC_WDAY_SHIFT) 141 | (tm->tm_hour << RTC_HOUR_SHIFT) 142 | (tm->tm_min << RTC_MIN_SHIFT) 143 | (tm->tm_sec << RTC_SEC_SHIFT); 144 145 return 0; 146 } 147 148 /* 149 * Convert ST v2 RTC format to Gregorian date. 150 */ 151 static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year, 152 struct rtc_time *tm) 153 { 154 tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100); 155 tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1; 156 tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT); 157 tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1; 158 tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT); 159 tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT); 160 tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT); 161 162 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 163 tm->tm_year -= 1900; 164 165 return 0; 166 } 167 168 static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm) 169 { 170 struct pl031_local *ldata = dev_get_drvdata(dev); 171 172 pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR), 173 readl(ldata->base + RTC_YDR), tm); 174 175 return 0; 176 } 177 178 static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm) 179 { 180 unsigned long time; 181 unsigned long bcd_year; 182 struct pl031_local *ldata = dev_get_drvdata(dev); 183 int ret; 184 185 ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year); 186 if (ret == 0) { 187 writel(bcd_year, ldata->base + RTC_YLR); 188 writel(time, ldata->base + RTC_LR); 189 } 190 191 return ret; 192 } 193 194 static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 195 { 196 struct pl031_local *ldata = dev_get_drvdata(dev); 197 int ret; 198 199 ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR), 200 readl(ldata->base + RTC_YMR), &alarm->time); 201 202 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 203 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 204 205 return ret; 206 } 207 208 static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 209 { 210 struct pl031_local *ldata = dev_get_drvdata(dev); 211 unsigned long time; 212 unsigned long bcd_year; 213 int ret; 214 215 ret = pl031_stv2_tm_to_time(dev, &alarm->time, 216 &time, &bcd_year); 217 if (ret == 0) { 218 writel(bcd_year, ldata->base + RTC_YMR); 219 writel(time, ldata->base + RTC_MR); 220 221 pl031_alarm_irq_enable(dev, alarm->enabled); 222 } 223 224 return ret; 225 } 226 227 static irqreturn_t pl031_interrupt(int irq, void *dev_id) 228 { 229 struct pl031_local *ldata = dev_id; 230 unsigned long rtcmis; 231 unsigned long events = 0; 232 233 rtcmis = readl(ldata->base + RTC_MIS); 234 if (rtcmis & RTC_BIT_AI) { 235 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 236 events |= (RTC_AF | RTC_IRQF); 237 rtc_update_irq(ldata->rtc, 1, events); 238 239 return IRQ_HANDLED; 240 } 241 242 return IRQ_NONE; 243 } 244 245 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 246 { 247 struct pl031_local *ldata = dev_get_drvdata(dev); 248 249 rtc_time64_to_tm(readl(ldata->base + RTC_DR), tm); 250 251 return 0; 252 } 253 254 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 255 { 256 struct pl031_local *ldata = dev_get_drvdata(dev); 257 258 writel(rtc_tm_to_time64(tm), ldata->base + RTC_LR); 259 260 return 0; 261 } 262 263 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 264 { 265 struct pl031_local *ldata = dev_get_drvdata(dev); 266 267 rtc_time64_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 268 269 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 270 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 271 272 return 0; 273 } 274 275 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 276 { 277 struct pl031_local *ldata = dev_get_drvdata(dev); 278 279 writel(rtc_tm_to_time64(&alarm->time), ldata->base + RTC_MR); 280 pl031_alarm_irq_enable(dev, alarm->enabled); 281 282 return 0; 283 } 284 285 static void pl031_remove(struct amba_device *adev) 286 { 287 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 288 289 if (adev->irq[0]) 290 free_irq(adev->irq[0], ldata); 291 amba_release_regions(adev); 292 } 293 294 static int pl031_probe(struct amba_device *adev, const struct amba_id *id) 295 { 296 int ret; 297 struct pl031_local *ldata; 298 struct pl031_vendor_data *vendor = id->data; 299 struct rtc_class_ops *ops; 300 unsigned long time, data; 301 302 ret = amba_request_regions(adev, NULL); 303 if (ret) 304 goto err_req; 305 306 ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local), 307 GFP_KERNEL); 308 ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops), 309 GFP_KERNEL); 310 if (!ldata || !ops) { 311 ret = -ENOMEM; 312 goto out; 313 } 314 315 ldata->vendor = vendor; 316 ldata->base = devm_ioremap(&adev->dev, adev->res.start, 317 resource_size(&adev->res)); 318 if (!ldata->base) { 319 ret = -ENOMEM; 320 goto out; 321 } 322 323 amba_set_drvdata(adev, ldata); 324 325 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev)); 326 dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); 327 328 data = readl(ldata->base + RTC_CR); 329 /* Enable the clockwatch on ST Variants */ 330 if (vendor->clockwatch) 331 data |= RTC_CR_CWEN; 332 else 333 data |= RTC_CR_EN; 334 writel(data, ldata->base + RTC_CR); 335 336 /* 337 * On ST PL031 variants, the RTC reset value does not provide correct 338 * weekday for 2000-01-01. Correct the erroneous sunday to saturday. 339 */ 340 if (vendor->st_weekday) { 341 if (readl(ldata->base + RTC_YDR) == 0x2000) { 342 time = readl(ldata->base + RTC_DR); 343 if ((time & 344 (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) 345 == 0x02120000) { 346 time = time | (0x7 << RTC_WDAY_SHIFT); 347 writel(0x2000, ldata->base + RTC_YLR); 348 writel(time, ldata->base + RTC_LR); 349 } 350 } 351 } 352 353 devm_device_init_wakeup(&adev->dev); 354 ldata->rtc = devm_rtc_allocate_device(&adev->dev); 355 if (IS_ERR(ldata->rtc)) { 356 ret = PTR_ERR(ldata->rtc); 357 goto out; 358 } 359 360 if (!adev->irq[0]) 361 clear_bit(RTC_FEATURE_ALARM, ldata->rtc->features); 362 363 ldata->rtc->ops = ops; 364 ldata->rtc->range_min = vendor->range_min; 365 ldata->rtc->range_max = vendor->range_max; 366 367 ret = devm_rtc_register_device(ldata->rtc); 368 if (ret) 369 goto out; 370 371 if (adev->irq[0]) { 372 ret = request_irq(adev->irq[0], pl031_interrupt, 373 vendor->irqflags, "rtc-pl031", ldata); 374 if (ret) 375 goto out; 376 devm_pm_set_wake_irq(&adev->dev, adev->irq[0]); 377 } 378 return 0; 379 380 out: 381 amba_release_regions(adev); 382 err_req: 383 384 return ret; 385 } 386 387 /* Operations for the original ARM version */ 388 static struct pl031_vendor_data arm_pl031 = { 389 .ops = { 390 .read_time = pl031_read_time, 391 .set_time = pl031_set_time, 392 .read_alarm = pl031_read_alarm, 393 .set_alarm = pl031_set_alarm, 394 .alarm_irq_enable = pl031_alarm_irq_enable, 395 }, 396 .range_max = U32_MAX, 397 }; 398 399 /* The First ST derivative */ 400 static struct pl031_vendor_data stv1_pl031 = { 401 .ops = { 402 .read_time = pl031_read_time, 403 .set_time = pl031_set_time, 404 .read_alarm = pl031_read_alarm, 405 .set_alarm = pl031_set_alarm, 406 .alarm_irq_enable = pl031_alarm_irq_enable, 407 }, 408 .clockwatch = true, 409 .st_weekday = true, 410 .range_max = U32_MAX, 411 }; 412 413 /* And the second ST derivative */ 414 static struct pl031_vendor_data stv2_pl031 = { 415 .ops = { 416 .read_time = pl031_stv2_read_time, 417 .set_time = pl031_stv2_set_time, 418 .read_alarm = pl031_stv2_read_alarm, 419 .set_alarm = pl031_stv2_set_alarm, 420 .alarm_irq_enable = pl031_alarm_irq_enable, 421 }, 422 .clockwatch = true, 423 .st_weekday = true, 424 /* 425 * This variant shares the IRQ with another block and must not 426 * suspend that IRQ line. 427 * TODO check if it shares with IRQF_NO_SUSPEND user, else we can 428 * remove IRQF_COND_SUSPEND 429 */ 430 .irqflags = IRQF_SHARED | IRQF_COND_SUSPEND, 431 .range_min = RTC_TIMESTAMP_BEGIN_0000, 432 .range_max = RTC_TIMESTAMP_END_9999, 433 }; 434 435 static const struct amba_id pl031_ids[] = { 436 { 437 .id = 0x00041031, 438 .mask = 0x000fffff, 439 .data = &arm_pl031, 440 }, 441 /* ST Micro variants */ 442 { 443 .id = 0x00180031, 444 .mask = 0x00ffffff, 445 .data = &stv1_pl031, 446 }, 447 { 448 .id = 0x00280031, 449 .mask = 0x00ffffff, 450 .data = &stv2_pl031, 451 }, 452 {0, 0}, 453 }; 454 455 MODULE_DEVICE_TABLE(amba, pl031_ids); 456 457 static struct amba_driver pl031_driver = { 458 .drv = { 459 .name = "rtc-pl031", 460 }, 461 .id_table = pl031_ids, 462 .probe = pl031_probe, 463 .remove = pl031_remove, 464 }; 465 466 module_amba_driver(pl031_driver); 467 468 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); 469 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 470 MODULE_LICENSE("GPL"); 471