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) { 224 writel(rtcmis, ldata->base + RTC_ICR); 225 226 if (rtcmis & RTC_BIT_AI) 227 events |= (RTC_AF | RTC_IRQF); 228 229 /* Timer interrupt is only available in ST variants */ 230 if ((rtcmis & RTC_BIT_PI) && 231 (ldata->hw_designer == AMBA_VENDOR_ST)) 232 events |= (RTC_PF | RTC_IRQF); 233 234 rtc_update_irq(ldata->rtc, 1, events); 235 236 return IRQ_HANDLED; 237 } 238 239 return IRQ_NONE; 240 } 241 242 static int pl031_read_time(struct device *dev, struct rtc_time *tm) 243 { 244 struct pl031_local *ldata = dev_get_drvdata(dev); 245 246 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 247 248 return 0; 249 } 250 251 static int pl031_set_time(struct device *dev, struct rtc_time *tm) 252 { 253 unsigned long time; 254 struct pl031_local *ldata = dev_get_drvdata(dev); 255 int ret; 256 257 ret = rtc_tm_to_time(tm, &time); 258 259 if (ret == 0) 260 writel(time, ldata->base + RTC_LR); 261 262 return ret; 263 } 264 265 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 266 { 267 struct pl031_local *ldata = dev_get_drvdata(dev); 268 269 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 270 271 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; 272 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 273 274 return 0; 275 } 276 277 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 278 { 279 struct pl031_local *ldata = dev_get_drvdata(dev); 280 unsigned long time; 281 int ret; 282 283 /* At the moment, we can only deal with non-wildcarded alarm times. */ 284 ret = rtc_valid_tm(&alarm->time); 285 if (ret == 0) { 286 ret = rtc_tm_to_time(&alarm->time, &time); 287 if (ret == 0) { 288 writel(time, ldata->base + RTC_MR); 289 pl031_alarm_irq_enable(dev, alarm->enabled); 290 } 291 } 292 293 return ret; 294 } 295 296 static int pl031_remove(struct amba_device *adev) 297 { 298 struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 299 300 amba_set_drvdata(adev, NULL); 301 free_irq(adev->irq[0], ldata->rtc); 302 rtc_device_unregister(ldata->rtc); 303 iounmap(ldata->base); 304 kfree(ldata); 305 amba_release_regions(adev); 306 307 return 0; 308 } 309 310 static int pl031_probe(struct amba_device *adev, const struct amba_id *id) 311 { 312 int ret; 313 struct pl031_local *ldata; 314 struct rtc_class_ops *ops = id->data; 315 316 ret = amba_request_regions(adev, NULL); 317 if (ret) 318 goto err_req; 319 320 ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL); 321 if (!ldata) { 322 ret = -ENOMEM; 323 goto out; 324 } 325 326 ldata->base = ioremap(adev->res.start, resource_size(&adev->res)); 327 328 if (!ldata->base) { 329 ret = -ENOMEM; 330 goto out_no_remap; 331 } 332 333 amba_set_drvdata(adev, ldata); 334 335 ldata->hw_designer = amba_manf(adev); 336 ldata->hw_revision = amba_rev(adev); 337 338 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer); 339 dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision); 340 341 /* Enable the clockwatch on ST Variants */ 342 if (ldata->hw_designer == AMBA_VENDOR_ST) 343 writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN, 344 ldata->base + RTC_CR); 345 346 ldata->rtc = rtc_device_register("pl031", &adev->dev, ops, 347 THIS_MODULE); 348 if (IS_ERR(ldata->rtc)) { 349 ret = PTR_ERR(ldata->rtc); 350 goto out_no_rtc; 351 } 352 353 if (request_irq(adev->irq[0], pl031_interrupt, 354 0, "rtc-pl031", ldata)) { 355 ret = -EIO; 356 goto out_no_irq; 357 } 358 359 return 0; 360 361 out_no_irq: 362 rtc_device_unregister(ldata->rtc); 363 out_no_rtc: 364 iounmap(ldata->base); 365 amba_set_drvdata(adev, NULL); 366 out_no_remap: 367 kfree(ldata); 368 out: 369 amba_release_regions(adev); 370 err_req: 371 372 return ret; 373 } 374 375 /* Operations for the original ARM version */ 376 static struct rtc_class_ops arm_pl031_ops = { 377 .read_time = pl031_read_time, 378 .set_time = pl031_set_time, 379 .read_alarm = pl031_read_alarm, 380 .set_alarm = pl031_set_alarm, 381 .alarm_irq_enable = pl031_alarm_irq_enable, 382 }; 383 384 /* The First ST derivative */ 385 static struct rtc_class_ops stv1_pl031_ops = { 386 .read_time = pl031_read_time, 387 .set_time = pl031_set_time, 388 .read_alarm = pl031_read_alarm, 389 .set_alarm = pl031_set_alarm, 390 .alarm_irq_enable = pl031_alarm_irq_enable, 391 }; 392 393 /* And the second ST derivative */ 394 static struct rtc_class_ops stv2_pl031_ops = { 395 .read_time = pl031_stv2_read_time, 396 .set_time = pl031_stv2_set_time, 397 .read_alarm = pl031_stv2_read_alarm, 398 .set_alarm = pl031_stv2_set_alarm, 399 .alarm_irq_enable = pl031_alarm_irq_enable, 400 }; 401 402 static struct amba_id pl031_ids[] = { 403 { 404 .id = 0x00041031, 405 .mask = 0x000fffff, 406 .data = &arm_pl031_ops, 407 }, 408 /* ST Micro variants */ 409 { 410 .id = 0x00180031, 411 .mask = 0x00ffffff, 412 .data = &stv1_pl031_ops, 413 }, 414 { 415 .id = 0x00280031, 416 .mask = 0x00ffffff, 417 .data = &stv2_pl031_ops, 418 }, 419 {0, 0}, 420 }; 421 422 MODULE_DEVICE_TABLE(amba, pl031_ids); 423 424 static struct amba_driver pl031_driver = { 425 .drv = { 426 .name = "rtc-pl031", 427 }, 428 .id_table = pl031_ids, 429 .probe = pl031_probe, 430 .remove = pl031_remove, 431 }; 432 433 module_amba_driver(pl031_driver); 434 435 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net"); 436 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); 437 MODULE_LICENSE("GPL"); 438