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