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 struct pl031_local { 72 struct rtc_device *rtc; 73 void __iomem *base; 74 u8 hw_designer; 75 u8 hw_revision:4; 76 }; 77 78 static int pl031_alarm_irq_enable(struct device *dev, 79 unsigned int enabled) 80 { 81 struct pl031_local *ldata = dev_get_drvdata(dev); 82 unsigned long imsc; 83 84 /* Clear any pending alarm interrupts. */ 85 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 86 87 imsc = readl(ldata->base + RTC_IMSC); 88 89 if (enabled == 1) 90 writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC); 91 else 92 writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC); 93 94 return 0; 95 } 96 97 /* 98 * Convert Gregorian date to ST v2 RTC format. 99 */ 100 static int pl031_stv2_tm_to_time(struct device *dev, 101 struct rtc_time *tm, unsigned long *st_time, 102 unsigned long *bcd_year) 103 { 104 int year = tm->tm_year + 1900; 105 int wday = tm->tm_wday; 106 107 /* wday masking is not working in hardware so wday must be valid */ 108 if (wday < -1 || wday > 6) { 109 dev_err(dev, "invalid wday value %d\n", tm->tm_wday); 110 return -EINVAL; 111 } else if (wday == -1) { 112 /* wday is not provided, calculate it here */ 113 unsigned long time; 114 struct rtc_time calc_tm; 115 116 rtc_tm_to_time(tm, &time); 117 rtc_time_to_tm(time, &calc_tm); 118 wday = calc_tm.tm_wday; 119 } 120 121 *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8); 122 123 *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT) 124 | (tm->tm_mday << RTC_MDAY_SHIFT) 125 | ((wday + 1) << RTC_WDAY_SHIFT) 126 | (tm->tm_hour << RTC_HOUR_SHIFT) 127 | (tm->tm_min << RTC_MIN_SHIFT) 128 | (tm->tm_sec << RTC_SEC_SHIFT); 129 130 return 0; 131 } 132 133 /* 134 * Convert ST v2 RTC format to Gregorian date. 135 */ 136 static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year, 137 struct rtc_time *tm) 138 { 139 tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100); 140 tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1; 141 tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT); 142 tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1; 143 tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT); 144 tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT); 145 tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT); 146 147 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); 148 tm->tm_year -= 1900; 149 150 return 0; 151 } 152 153 static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm) 154 { 155 struct pl031_local *ldata = dev_get_drvdata(dev); 156 157 pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR), 158 readl(ldata->base + RTC_YDR), tm); 159 160 return 0; 161 } 162 163 static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm) 164 { 165 unsigned long time; 166 unsigned long bcd_year; 167 struct pl031_local *ldata = dev_get_drvdata(dev); 168 int ret; 169 170 ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year); 171 if (ret == 0) { 172 writel(bcd_year, ldata->base + RTC_YLR); 173 writel(time, ldata->base + RTC_LR); 174 } 175 176 return ret; 177 } 178 179 static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 180 { 181 struct pl031_local *ldata = dev_get_drvdata(dev); 182 int ret; 183 184 ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR), 185 readl(ldata->base + RTC_YMR), &alarm->time); 186 187 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 188 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 189 190 return ret; 191 } 192 193 static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 194 { 195 struct pl031_local *ldata = dev_get_drvdata(dev); 196 unsigned long time; 197 unsigned long bcd_year; 198 int ret; 199 200 /* At the moment, we can only deal with non-wildcarded alarm times. */ 201 ret = rtc_valid_tm(&alarm->time); 202 if (ret == 0) { 203 ret = pl031_stv2_tm_to_time(dev, &alarm->time, 204 &time, &bcd_year); 205 if (ret == 0) { 206 writel(bcd_year, ldata->base + RTC_YMR); 207 writel(time, ldata->base + RTC_MR); 208 209 pl031_alarm_irq_enable(dev, alarm->enabled); 210 } 211 } 212 213 return ret; 214 } 215 216 static irqreturn_t pl031_interrupt(int irq, void *dev_id) 217 { 218 struct pl031_local *ldata = dev_id; 219 unsigned long rtcmis; 220 unsigned long events = 0; 221 222 rtcmis = readl(ldata->base + RTC_MIS); 223 if (rtcmis & RTC_BIT_AI) { 224 writel(RTC_BIT_AI, ldata->base + RTC_ICR); 225 events |= (RTC_AF | RTC_IRQF); 226 rtc_update_irq(ldata->rtc, 1, events); 227 228 return IRQ_HANDLED; 229 } 230 231 return IRQ_NONE; 232 } 233 234 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 235 { 236 struct pl031_local *ldata = dev_get_drvdata(dev); 237 238 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 239 240 return 0; 241 } 242 243 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 244 { 245 unsigned long time; 246 struct pl031_local *ldata = dev_get_drvdata(dev); 247 int ret; 248 249 ret = rtc_tm_to_time(tm, &time); 250 251 if (ret == 0) 252 writel(time, ldata->base + RTC_LR); 253 254 return ret; 255 } 256 257 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 258 { 259 struct pl031_local *ldata = dev_get_drvdata(dev); 260 261 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 262 263 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 264 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 265 266 return 0; 267 } 268 269 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 270 { 271 struct pl031_local *ldata = dev_get_drvdata(dev); 272 unsigned long time; 273 int ret; 274 275 /* At the moment, we can only deal with non-wildcarded alarm times. */ 276 ret = rtc_valid_tm(&alarm->time); 277 if (ret == 0) { 278 ret = rtc_tm_to_time(&alarm->time, &time); 279 if (ret == 0) { 280 writel(time, ldata->base + RTC_MR); 281 pl031_alarm_irq_enable(dev, alarm->enabled); 282 } 283 } 284 285 return ret; 286 } 287 288 static int pl031_remove(struct amba_device *adev) 289 { 290 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 291 292 amba_set_drvdata(adev, NULL); 293 free_irq(adev->irq[0], ldata->rtc); 294 rtc_device_unregister(ldata->rtc); 295 iounmap(ldata->base); 296 kfree(ldata); 297 amba_release_regions(adev); 298 299 return 0; 300 } 301 302 static int pl031_probe(struct amba_device *adev, const struct amba_id *id) 303 { 304 int ret; 305 struct pl031_local *ldata; 306 struct rtc_class_ops *ops = id->data; 307 unsigned long time; 308 309 ret = amba_request_regions(adev, NULL); 310 if (ret) 311 goto err_req; 312 313 ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL); 314 if (!ldata) { 315 ret = -ENOMEM; 316 goto out; 317 } 318 319 ldata->base = ioremap(adev->res.start, resource_size(&adev->res)); 320 321 if (!ldata->base) { 322 ret = -ENOMEM; 323 goto out_no_remap; 324 } 325 326 amba_set_drvdata(adev, ldata); 327 328 ldata->hw_designer = amba_manf(adev); 329 ldata->hw_revision = amba_rev(adev); 330 331 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer); 332 dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision); 333 334 /* Enable the clockwatch on ST Variants */ 335 if (ldata->hw_designer == AMBA_VENDOR_ST) 336 writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN, 337 ldata->base + RTC_CR); 338 339 /* 340 * On ST PL031 variants, the RTC reset value does not provide correct 341 * weekday for 2000-01-01. Correct the erroneous sunday to saturday. 342 */ 343 if (ldata->hw_designer == AMBA_VENDOR_ST) { 344 if (readl(ldata->base + RTC_YDR) == 0x2000) { 345 time = readl(ldata->base + RTC_DR); 346 if ((time & 347 (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) 348 == 0x02120000) { 349 time = time | (0x7 << RTC_WDAY_SHIFT); 350 writel(0x2000, ldata->base + RTC_YLR); 351 writel(time, ldata->base + RTC_LR); 352 } 353 } 354 } 355 356 ldata->rtc = rtc_device_register("pl031", &adev->dev, ops, 357 THIS_MODULE); 358 if (IS_ERR(ldata->rtc)) { 359 ret = PTR_ERR(ldata->rtc); 360 goto out_no_rtc; 361 } 362 363 if (request_irq(adev->irq[0], pl031_interrupt, 364 0, "rtc-pl031", ldata)) { 365 ret = -EIO; 366 goto out_no_irq; 367 } 368 369 return 0; 370 371 out_no_irq: 372 rtc_device_unregister(ldata->rtc); 373 out_no_rtc: 374 iounmap(ldata->base); 375 amba_set_drvdata(adev, NULL); 376 out_no_remap: 377 kfree(ldata); 378 out: 379 amba_release_regions(adev); 380 err_req: 381 382 return ret; 383 } 384 385 /* Operations for the original ARM version */ 386 static struct rtc_class_ops arm_pl031_ops = { 387 .read_time = pl031_read_time, 388 .set_time = pl031_set_time, 389 .read_alarm = pl031_read_alarm, 390 .set_alarm = pl031_set_alarm, 391 .alarm_irq_enable = pl031_alarm_irq_enable, 392 }; 393 394 /* The First ST derivative */ 395 static struct rtc_class_ops stv1_pl031_ops = { 396 .read_time = pl031_read_time, 397 .set_time = pl031_set_time, 398 .read_alarm = pl031_read_alarm, 399 .set_alarm = pl031_set_alarm, 400 .alarm_irq_enable = pl031_alarm_irq_enable, 401 }; 402 403 /* And the second ST derivative */ 404 static struct rtc_class_ops stv2_pl031_ops = { 405 .read_time = pl031_stv2_read_time, 406 .set_time = pl031_stv2_set_time, 407 .read_alarm = pl031_stv2_read_alarm, 408 .set_alarm = pl031_stv2_set_alarm, 409 .alarm_irq_enable = pl031_alarm_irq_enable, 410 }; 411 412 static struct amba_id pl031_ids[] = { 413 { 414 .id = 0x00041031, 415 .mask = 0x000fffff, 416 .data = &arm_pl031_ops, 417 }, 418 /* ST Micro variants */ 419 { 420 .id = 0x00180031, 421 .mask = 0x00ffffff, 422 .data = &stv1_pl031_ops, 423 }, 424 { 425 .id = 0x00280031, 426 .mask = 0x00ffffff, 427 .data = &stv2_pl031_ops, 428 }, 429 {0, 0}, 430 }; 431 432 MODULE_DEVICE_TABLE(amba, pl031_ids); 433 434 static struct amba_driver pl031_driver = { 435 .drv = { 436 .name = "rtc-pl031", 437 }, 438 .id_table = pl031_ids, 439 .probe = pl031_probe, 440 .remove = pl031_remove, 441 }; 442 443 module_amba_driver(pl031_driver); 444 445 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net"); 446 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 447 MODULE_LICENSE("GPL"); 448