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_CWEN (1 << 26) /* Clockwatch enable bit */ 48 49 #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */ 50 51 /* Common bit definitions for Interrupt status and control registers */ 52 #define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */ 53 #define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */ 54 55 /* Common bit definations for ST v2 for reading/writing time */ 56 #define RTC_SEC_SHIFT 0 57 #define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */ 58 #define RTC_MIN_SHIFT 6 59 #define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */ 60 #define RTC_HOUR_SHIFT 12 61 #define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */ 62 #define RTC_WDAY_SHIFT 17 63 #define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */ 64 #define RTC_MDAY_SHIFT 20 65 #define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */ 66 #define RTC_MON_SHIFT 25 67 #define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */ 68 69 #define RTC_TIMER_FREQ 32768 70 71 /** 72 * struct pl031_vendor_data - per-vendor variations 73 * @ops: the vendor-specific operations used on this silicon version 74 * @clockwatch: if this is an ST Microelectronics silicon version with a 75 * clockwatch function 76 * @st_weekday: if this is an ST Microelectronics silicon version that need 77 * the weekday fix 78 * @irqflags: special IRQ flags per variant 79 */ 80 struct pl031_vendor_data { 81 struct rtc_class_ops ops; 82 bool clockwatch; 83 bool st_weekday; 84 unsigned long irqflags; 85 }; 86 87 struct pl031_local { 88 struct pl031_vendor_data *vendor; 89 struct rtc_device *rtc; 90 void __iomem *base; 91 }; 92 93 static int pl031_alarm_irq_enable(struct device *dev, 94 unsigned int enabled) 95 { 96 struct pl031_local *ldata = dev_get_drvdata(dev); 97 unsigned long imsc; 98 99 /* Clear any pending alarm interrupts. */ 100 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 101 102 imsc = readl(ldata->base + RTC_IMSC); 103 104 if (enabled == 1) 105 writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC); 106 else 107 writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC); 108 109 return 0; 110 } 111 112 /* 113 * Convert Gregorian date to ST v2 RTC format. 114 */ 115 static int pl031_stv2_tm_to_time(struct device *dev, 116 struct rtc_time *tm, unsigned long *st_time, 117 unsigned long *bcd_year) 118 { 119 int year = tm->tm_year + 1900; 120 int wday = tm->tm_wday; 121 122 /* wday masking is not working in hardware so wday must be valid */ 123 if (wday < -1 || wday > 6) { 124 dev_err(dev, "invalid wday value %d\n", tm->tm_wday); 125 return -EINVAL; 126 } else if (wday == -1) { 127 /* wday is not provided, calculate it here */ 128 unsigned long time; 129 struct rtc_time calc_tm; 130 131 rtc_tm_to_time(tm, &time); 132 rtc_time_to_tm(time, &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 /* At the moment, we can only deal with non-wildcarded alarm times. */ 216 ret = rtc_valid_tm(&alarm->time); 217 if (ret == 0) { 218 ret = pl031_stv2_tm_to_time(dev, &alarm->time, 219 &time, &bcd_year); 220 if (ret == 0) { 221 writel(bcd_year, ldata->base + RTC_YMR); 222 writel(time, ldata->base + RTC_MR); 223 224 pl031_alarm_irq_enable(dev, alarm->enabled); 225 } 226 } 227 228 return ret; 229 } 230 231 static irqreturn_t pl031_interrupt(int irq, void *dev_id) 232 { 233 struct pl031_local *ldata = dev_id; 234 unsigned long rtcmis; 235 unsigned long events = 0; 236 237 rtcmis = readl(ldata->base + RTC_MIS); 238 if (rtcmis & RTC_BIT_AI) { 239 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 240 events |= (RTC_AF | RTC_IRQF); 241 rtc_update_irq(ldata->rtc, 1, events); 242 243 return IRQ_HANDLED; 244 } 245 246 return IRQ_NONE; 247 } 248 249 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 250 { 251 struct pl031_local *ldata = dev_get_drvdata(dev); 252 253 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 254 255 return 0; 256 } 257 258 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 259 { 260 unsigned long time; 261 struct pl031_local *ldata = dev_get_drvdata(dev); 262 int ret; 263 264 ret = rtc_tm_to_time(tm, &time); 265 266 if (ret == 0) 267 writel(time, ldata->base + RTC_LR); 268 269 return ret; 270 } 271 272 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 273 { 274 struct pl031_local *ldata = dev_get_drvdata(dev); 275 276 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 277 278 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 279 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 280 281 return 0; 282 } 283 284 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 285 { 286 struct pl031_local *ldata = dev_get_drvdata(dev); 287 unsigned long time; 288 int ret; 289 290 /* At the moment, we can only deal with non-wildcarded alarm times. */ 291 ret = rtc_valid_tm(&alarm->time); 292 if (ret == 0) { 293 ret = rtc_tm_to_time(&alarm->time, &time); 294 if (ret == 0) { 295 writel(time, ldata->base + RTC_MR); 296 pl031_alarm_irq_enable(dev, alarm->enabled); 297 } 298 } 299 300 return ret; 301 } 302 303 static int pl031_remove(struct amba_device *adev) 304 { 305 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 306 307 amba_set_drvdata(adev, NULL); 308 free_irq(adev->irq[0], ldata->rtc); 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; 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 /* Enable the clockwatch on ST Variants */ 349 if (vendor->clockwatch) 350 writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN, 351 ldata->base + RTC_CR); 352 353 /* 354 * On ST PL031 variants, the RTC reset value does not provide correct 355 * weekday for 2000-01-01. Correct the erroneous sunday to saturday. 356 */ 357 if (vendor->st_weekday) { 358 if (readl(ldata->base + RTC_YDR) == 0x2000) { 359 time = readl(ldata->base + RTC_DR); 360 if ((time & 361 (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) 362 == 0x02120000) { 363 time = time | (0x7 << RTC_WDAY_SHIFT); 364 writel(0x2000, ldata->base + RTC_YLR); 365 writel(time, ldata->base + RTC_LR); 366 } 367 } 368 } 369 370 ldata->rtc = rtc_device_register("pl031", &adev->dev, ops, 371 THIS_MODULE); 372 if (IS_ERR(ldata->rtc)) { 373 ret = PTR_ERR(ldata->rtc); 374 goto out_no_rtc; 375 } 376 377 if (request_irq(adev->irq[0], pl031_interrupt, 378 vendor->irqflags, "rtc-pl031", ldata)) { 379 ret = -EIO; 380 goto out_no_irq; 381 } 382 383 return 0; 384 385 out_no_irq: 386 rtc_device_unregister(ldata->rtc); 387 out_no_rtc: 388 iounmap(ldata->base); 389 amba_set_drvdata(adev, NULL); 390 out_no_remap: 391 kfree(ldata); 392 out: 393 amba_release_regions(adev); 394 err_req: 395 396 return ret; 397 } 398 399 /* Operations for the original ARM version */ 400 static struct pl031_vendor_data arm_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 .irqflags = IRQF_NO_SUSPEND, 409 }; 410 411 /* The First ST derivative */ 412 static struct pl031_vendor_data stv1_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 .clockwatch = true, 421 .st_weekday = true, 422 .irqflags = IRQF_NO_SUSPEND, 423 }; 424 425 /* And the second ST derivative */ 426 static struct pl031_vendor_data stv2_pl031 = { 427 .ops = { 428 .read_time = pl031_stv2_read_time, 429 .set_time = pl031_stv2_set_time, 430 .read_alarm = pl031_stv2_read_alarm, 431 .set_alarm = pl031_stv2_set_alarm, 432 .alarm_irq_enable = pl031_alarm_irq_enable, 433 }, 434 .clockwatch = true, 435 .st_weekday = true, 436 /* 437 * This variant shares the IRQ with another block and must not 438 * suspend that IRQ line. 439 */ 440 .irqflags = IRQF_SHARED | IRQF_NO_SUSPEND, 441 }; 442 443 static struct amba_id pl031_ids[] = { 444 { 445 .id = 0x00041031, 446 .mask = 0x000fffff, 447 .data = &arm_pl031, 448 }, 449 /* ST Micro variants */ 450 { 451 .id = 0x00180031, 452 .mask = 0x00ffffff, 453 .data = &stv1_pl031, 454 }, 455 { 456 .id = 0x00280031, 457 .mask = 0x00ffffff, 458 .data = &stv2_pl031, 459 }, 460 {0, 0}, 461 }; 462 463 MODULE_DEVICE_TABLE(amba, pl031_ids); 464 465 static struct amba_driver pl031_driver = { 466 .drv = { 467 .name = "rtc-pl031", 468 }, 469 .id_table = pl031_ids, 470 .probe = pl031_probe, 471 .remove = pl031_remove, 472 }; 473 474 module_amba_driver(pl031_driver); 475 476 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net"); 477 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 478 MODULE_LICENSE("GPL"); 479