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 free_irq(adev->irq[0], ldata); 312 rtc_device_unregister(ldata->rtc); 313 iounmap(ldata->base); 314 kfree(ldata); 315 amba_release_regions(adev); 316 317 return 0; 318 } 319 320 static int pl031_probe(struct amba_device *adev, const struct amba_id *id) 321 { 322 int ret; 323 struct pl031_local *ldata; 324 struct pl031_vendor_data *vendor = id->data; 325 struct rtc_class_ops *ops = &vendor->ops; 326 unsigned long time, data; 327 328 ret = amba_request_regions(adev, NULL); 329 if (ret) 330 goto err_req; 331 332 ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL); 333 if (!ldata) { 334 ret = -ENOMEM; 335 goto out; 336 } 337 ldata->vendor = vendor; 338 339 ldata->base = ioremap(adev->res.start, resource_size(&adev->res)); 340 341 if (!ldata->base) { 342 ret = -ENOMEM; 343 goto out_no_remap; 344 } 345 346 amba_set_drvdata(adev, ldata); 347 348 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev)); 349 dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); 350 351 data = readl(ldata->base + RTC_CR); 352 /* Enable the clockwatch on ST Variants */ 353 if (vendor->clockwatch) 354 data |= RTC_CR_CWEN; 355 else 356 data |= RTC_CR_EN; 357 writel(data, ldata->base + RTC_CR); 358 359 /* 360 * On ST PL031 variants, the RTC reset value does not provide correct 361 * weekday for 2000-01-01. Correct the erroneous sunday to saturday. 362 */ 363 if (vendor->st_weekday) { 364 if (readl(ldata->base + RTC_YDR) == 0x2000) { 365 time = readl(ldata->base + RTC_DR); 366 if ((time & 367 (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) 368 == 0x02120000) { 369 time = time | (0x7 << RTC_WDAY_SHIFT); 370 writel(0x2000, ldata->base + RTC_YLR); 371 writel(time, ldata->base + RTC_LR); 372 } 373 } 374 } 375 376 device_init_wakeup(&adev->dev, true); 377 ldata->rtc = rtc_device_register("pl031", &adev->dev, ops, 378 THIS_MODULE); 379 if (IS_ERR(ldata->rtc)) { 380 ret = PTR_ERR(ldata->rtc); 381 goto out_no_rtc; 382 } 383 384 if (request_irq(adev->irq[0], pl031_interrupt, 385 vendor->irqflags, "rtc-pl031", ldata)) { 386 ret = -EIO; 387 goto out_no_irq; 388 } 389 dev_pm_set_wake_irq(&adev->dev, adev->irq[0]); 390 return 0; 391 392 out_no_irq: 393 rtc_device_unregister(ldata->rtc); 394 out_no_rtc: 395 iounmap(ldata->base); 396 out_no_remap: 397 kfree(ldata); 398 out: 399 amba_release_regions(adev); 400 err_req: 401 402 return ret; 403 } 404 405 /* Operations for the original ARM version */ 406 static struct pl031_vendor_data arm_pl031 = { 407 .ops = { 408 .read_time = pl031_read_time, 409 .set_time = pl031_set_time, 410 .read_alarm = pl031_read_alarm, 411 .set_alarm = pl031_set_alarm, 412 .alarm_irq_enable = pl031_alarm_irq_enable, 413 }, 414 }; 415 416 /* The First ST derivative */ 417 static struct pl031_vendor_data stv1_pl031 = { 418 .ops = { 419 .read_time = pl031_read_time, 420 .set_time = pl031_set_time, 421 .read_alarm = pl031_read_alarm, 422 .set_alarm = pl031_set_alarm, 423 .alarm_irq_enable = pl031_alarm_irq_enable, 424 }, 425 .clockwatch = true, 426 .st_weekday = true, 427 }; 428 429 /* And the second ST derivative */ 430 static struct pl031_vendor_data stv2_pl031 = { 431 .ops = { 432 .read_time = pl031_stv2_read_time, 433 .set_time = pl031_stv2_set_time, 434 .read_alarm = pl031_stv2_read_alarm, 435 .set_alarm = pl031_stv2_set_alarm, 436 .alarm_irq_enable = pl031_alarm_irq_enable, 437 }, 438 .clockwatch = true, 439 .st_weekday = true, 440 /* 441 * This variant shares the IRQ with another block and must not 442 * suspend that IRQ line. 443 * TODO check if it shares with IRQF_NO_SUSPEND user, else we can 444 * remove IRQF_COND_SUSPEND 445 */ 446 .irqflags = IRQF_SHARED | IRQF_COND_SUSPEND, 447 }; 448 449 static struct amba_id pl031_ids[] = { 450 { 451 .id = 0x00041031, 452 .mask = 0x000fffff, 453 .data = &arm_pl031, 454 }, 455 /* ST Micro variants */ 456 { 457 .id = 0x00180031, 458 .mask = 0x00ffffff, 459 .data = &stv1_pl031, 460 }, 461 { 462 .id = 0x00280031, 463 .mask = 0x00ffffff, 464 .data = &stv2_pl031, 465 }, 466 {0, 0}, 467 }; 468 469 MODULE_DEVICE_TABLE(amba, pl031_ids); 470 471 static struct amba_driver pl031_driver = { 472 .drv = { 473 .name = "rtc-pl031", 474 }, 475 .id_table = pl031_ids, 476 .probe = pl031_probe, 477 .remove = pl031_remove, 478 }; 479 480 module_amba_driver(pl031_driver); 481 482 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); 483 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 484 MODULE_LICENSE("GPL"); 485