1 /* 2 * An RTC driver for Allwinner A10/A20 3 * 4 * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along 17 * with this program; if not, write to the Free Software Foundation, Inc., 18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 19 */ 20 21 #include <linux/delay.h> 22 #include <linux/err.h> 23 #include <linux/fs.h> 24 #include <linux/init.h> 25 #include <linux/interrupt.h> 26 #include <linux/io.h> 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/of.h> 30 #include <linux/of_address.h> 31 #include <linux/of_device.h> 32 #include <linux/platform_device.h> 33 #include <linux/rtc.h> 34 #include <linux/types.h> 35 36 #define SUNXI_LOSC_CTRL 0x0000 37 #define SUNXI_LOSC_CTRL_RTC_HMS_ACC BIT(8) 38 #define SUNXI_LOSC_CTRL_RTC_YMD_ACC BIT(7) 39 40 #define SUNXI_RTC_YMD 0x0004 41 42 #define SUNXI_RTC_HMS 0x0008 43 44 #define SUNXI_ALRM_DHMS 0x000c 45 46 #define SUNXI_ALRM_EN 0x0014 47 #define SUNXI_ALRM_EN_CNT_EN BIT(8) 48 49 #define SUNXI_ALRM_IRQ_EN 0x0018 50 #define SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0) 51 52 #define SUNXI_ALRM_IRQ_STA 0x001c 53 #define SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0) 54 55 #define SUNXI_MASK_DH 0x0000001f 56 #define SUNXI_MASK_SM 0x0000003f 57 #define SUNXI_MASK_M 0x0000000f 58 #define SUNXI_MASK_LY 0x00000001 59 #define SUNXI_MASK_D 0x00000ffe 60 #define SUNXI_MASK_M 0x0000000f 61 62 #define SUNXI_GET(x, mask, shift) (((x) & ((mask) << (shift))) \ 63 >> (shift)) 64 65 #define SUNXI_SET(x, mask, shift) (((x) & (mask)) << (shift)) 66 67 /* 68 * Get date values 69 */ 70 #define SUNXI_DATE_GET_DAY_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 0) 71 #define SUNXI_DATE_GET_MON_VALUE(x) SUNXI_GET(x, SUNXI_MASK_M, 8) 72 #define SUNXI_DATE_GET_YEAR_VALUE(x, mask) SUNXI_GET(x, mask, 16) 73 74 /* 75 * Get time values 76 */ 77 #define SUNXI_TIME_GET_SEC_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 0) 78 #define SUNXI_TIME_GET_MIN_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 8) 79 #define SUNXI_TIME_GET_HOUR_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 16) 80 81 /* 82 * Get alarm values 83 */ 84 #define SUNXI_ALRM_GET_SEC_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 0) 85 #define SUNXI_ALRM_GET_MIN_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 8) 86 #define SUNXI_ALRM_GET_HOUR_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 16) 87 88 /* 89 * Set date values 90 */ 91 #define SUNXI_DATE_SET_DAY_VALUE(x) SUNXI_DATE_GET_DAY_VALUE(x) 92 #define SUNXI_DATE_SET_MON_VALUE(x) SUNXI_SET(x, SUNXI_MASK_M, 8) 93 #define SUNXI_DATE_SET_YEAR_VALUE(x, mask) SUNXI_SET(x, mask, 16) 94 #define SUNXI_LEAP_SET_VALUE(x, shift) SUNXI_SET(x, SUNXI_MASK_LY, shift) 95 96 /* 97 * Set time values 98 */ 99 #define SUNXI_TIME_SET_SEC_VALUE(x) SUNXI_TIME_GET_SEC_VALUE(x) 100 #define SUNXI_TIME_SET_MIN_VALUE(x) SUNXI_SET(x, SUNXI_MASK_SM, 8) 101 #define SUNXI_TIME_SET_HOUR_VALUE(x) SUNXI_SET(x, SUNXI_MASK_DH, 16) 102 103 /* 104 * Set alarm values 105 */ 106 #define SUNXI_ALRM_SET_SEC_VALUE(x) SUNXI_ALRM_GET_SEC_VALUE(x) 107 #define SUNXI_ALRM_SET_MIN_VALUE(x) SUNXI_SET(x, SUNXI_MASK_SM, 8) 108 #define SUNXI_ALRM_SET_HOUR_VALUE(x) SUNXI_SET(x, SUNXI_MASK_DH, 16) 109 #define SUNXI_ALRM_SET_DAY_VALUE(x) SUNXI_SET(x, SUNXI_MASK_D, 21) 110 111 /* 112 * Time unit conversions 113 */ 114 #define SEC_IN_MIN 60 115 #define SEC_IN_HOUR (60 * SEC_IN_MIN) 116 #define SEC_IN_DAY (24 * SEC_IN_HOUR) 117 118 /* 119 * The year parameter passed to the driver is usually an offset relative to 120 * the year 1900. This macro is used to convert this offset to another one 121 * relative to the minimum year allowed by the hardware. 122 */ 123 #define SUNXI_YEAR_OFF(x) ((x)->min - 1900) 124 125 /* 126 * min and max year are arbitrary set considering the limited range of the 127 * hardware register field 128 */ 129 struct sunxi_rtc_data_year { 130 unsigned int min; /* min year allowed */ 131 unsigned int max; /* max year allowed */ 132 unsigned int mask; /* mask for the year field */ 133 unsigned char leap_shift; /* bit shift to get the leap year */ 134 }; 135 136 static struct sunxi_rtc_data_year data_year_param[] = { 137 [0] = { 138 .min = 2010, 139 .max = 2073, 140 .mask = 0x3f, 141 .leap_shift = 22, 142 }, 143 [1] = { 144 .min = 1970, 145 .max = 2225, 146 .mask = 0xff, 147 .leap_shift = 24, 148 }, 149 }; 150 151 struct sunxi_rtc_dev { 152 struct rtc_device *rtc; 153 struct device *dev; 154 struct sunxi_rtc_data_year *data_year; 155 void __iomem *base; 156 int irq; 157 }; 158 159 static irqreturn_t sunxi_rtc_alarmirq(int irq, void *id) 160 { 161 struct sunxi_rtc_dev *chip = (struct sunxi_rtc_dev *) id; 162 u32 val; 163 164 val = readl(chip->base + SUNXI_ALRM_IRQ_STA); 165 166 if (val & SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND) { 167 val |= SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND; 168 writel(val, chip->base + SUNXI_ALRM_IRQ_STA); 169 170 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); 171 172 return IRQ_HANDLED; 173 } 174 175 return IRQ_NONE; 176 } 177 178 static void sunxi_rtc_setaie(int to, struct sunxi_rtc_dev *chip) 179 { 180 u32 alrm_val = 0; 181 u32 alrm_irq_val = 0; 182 183 if (to) { 184 alrm_val = readl(chip->base + SUNXI_ALRM_EN); 185 alrm_val |= SUNXI_ALRM_EN_CNT_EN; 186 187 alrm_irq_val = readl(chip->base + SUNXI_ALRM_IRQ_EN); 188 alrm_irq_val |= SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN; 189 } else { 190 writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, 191 chip->base + SUNXI_ALRM_IRQ_STA); 192 } 193 194 writel(alrm_val, chip->base + SUNXI_ALRM_EN); 195 writel(alrm_irq_val, chip->base + SUNXI_ALRM_IRQ_EN); 196 } 197 198 static int sunxi_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm) 199 { 200 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); 201 struct rtc_time *alrm_tm = &wkalrm->time; 202 u32 alrm; 203 u32 alrm_en; 204 u32 date; 205 206 alrm = readl(chip->base + SUNXI_ALRM_DHMS); 207 date = readl(chip->base + SUNXI_RTC_YMD); 208 209 alrm_tm->tm_sec = SUNXI_ALRM_GET_SEC_VALUE(alrm); 210 alrm_tm->tm_min = SUNXI_ALRM_GET_MIN_VALUE(alrm); 211 alrm_tm->tm_hour = SUNXI_ALRM_GET_HOUR_VALUE(alrm); 212 213 alrm_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date); 214 alrm_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date); 215 alrm_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date, 216 chip->data_year->mask); 217 218 alrm_tm->tm_mon -= 1; 219 220 /* 221 * switch from (data_year->min)-relative offset to 222 * a (1900)-relative one 223 */ 224 alrm_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year); 225 226 alrm_en = readl(chip->base + SUNXI_ALRM_IRQ_EN); 227 if (alrm_en & SUNXI_ALRM_EN_CNT_EN) 228 wkalrm->enabled = 1; 229 230 return 0; 231 } 232 233 static int sunxi_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 234 { 235 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); 236 u32 date, time; 237 238 /* 239 * read again in case it changes 240 */ 241 do { 242 date = readl(chip->base + SUNXI_RTC_YMD); 243 time = readl(chip->base + SUNXI_RTC_HMS); 244 } while ((date != readl(chip->base + SUNXI_RTC_YMD)) || 245 (time != readl(chip->base + SUNXI_RTC_HMS))); 246 247 rtc_tm->tm_sec = SUNXI_TIME_GET_SEC_VALUE(time); 248 rtc_tm->tm_min = SUNXI_TIME_GET_MIN_VALUE(time); 249 rtc_tm->tm_hour = SUNXI_TIME_GET_HOUR_VALUE(time); 250 251 rtc_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date); 252 rtc_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date); 253 rtc_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date, 254 chip->data_year->mask); 255 256 rtc_tm->tm_mon -= 1; 257 258 /* 259 * switch from (data_year->min)-relative offset to 260 * a (1900)-relative one 261 */ 262 rtc_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year); 263 264 return rtc_valid_tm(rtc_tm); 265 } 266 267 static int sunxi_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) 268 { 269 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); 270 struct rtc_time *alrm_tm = &wkalrm->time; 271 struct rtc_time tm_now; 272 u32 alrm; 273 time64_t diff; 274 unsigned long time_gap; 275 unsigned long time_gap_day; 276 unsigned long time_gap_hour; 277 unsigned long time_gap_min; 278 int ret; 279 280 ret = sunxi_rtc_gettime(dev, &tm_now); 281 if (ret < 0) { 282 dev_err(dev, "Error in getting time\n"); 283 return -EINVAL; 284 } 285 286 diff = rtc_tm_sub(alrm_tm, &tm_now); 287 if (diff <= 0) { 288 dev_err(dev, "Date to set in the past\n"); 289 return -EINVAL; 290 } 291 292 if (diff > 255 * SEC_IN_DAY) { 293 dev_err(dev, "Day must be in the range 0 - 255\n"); 294 return -EINVAL; 295 } 296 297 time_gap = diff; 298 time_gap_day = time_gap / SEC_IN_DAY; 299 time_gap -= time_gap_day * SEC_IN_DAY; 300 time_gap_hour = time_gap / SEC_IN_HOUR; 301 time_gap -= time_gap_hour * SEC_IN_HOUR; 302 time_gap_min = time_gap / SEC_IN_MIN; 303 time_gap -= time_gap_min * SEC_IN_MIN; 304 305 sunxi_rtc_setaie(0, chip); 306 writel(0, chip->base + SUNXI_ALRM_DHMS); 307 usleep_range(100, 300); 308 309 alrm = SUNXI_ALRM_SET_SEC_VALUE(time_gap) | 310 SUNXI_ALRM_SET_MIN_VALUE(time_gap_min) | 311 SUNXI_ALRM_SET_HOUR_VALUE(time_gap_hour) | 312 SUNXI_ALRM_SET_DAY_VALUE(time_gap_day); 313 writel(alrm, chip->base + SUNXI_ALRM_DHMS); 314 315 writel(0, chip->base + SUNXI_ALRM_IRQ_EN); 316 writel(SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN, chip->base + SUNXI_ALRM_IRQ_EN); 317 318 sunxi_rtc_setaie(wkalrm->enabled, chip); 319 320 return 0; 321 } 322 323 static int sunxi_rtc_wait(struct sunxi_rtc_dev *chip, int offset, 324 unsigned int mask, unsigned int ms_timeout) 325 { 326 const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout); 327 u32 reg; 328 329 do { 330 reg = readl(chip->base + offset); 331 reg &= mask; 332 333 if (reg == mask) 334 return 0; 335 336 } while (time_before(jiffies, timeout)); 337 338 return -ETIMEDOUT; 339 } 340 341 static int sunxi_rtc_settime(struct device *dev, struct rtc_time *rtc_tm) 342 { 343 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); 344 u32 date = 0; 345 u32 time = 0; 346 int year; 347 348 /* 349 * the input rtc_tm->tm_year is the offset relative to 1900. We use 350 * the SUNXI_YEAR_OFF macro to rebase it with respect to the min year 351 * allowed by the hardware 352 */ 353 354 year = rtc_tm->tm_year + 1900; 355 if (year < chip->data_year->min || year > chip->data_year->max) { 356 dev_err(dev, "rtc only supports year in range %d - %d\n", 357 chip->data_year->min, chip->data_year->max); 358 return -EINVAL; 359 } 360 361 rtc_tm->tm_year -= SUNXI_YEAR_OFF(chip->data_year); 362 rtc_tm->tm_mon += 1; 363 364 date = SUNXI_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) | 365 SUNXI_DATE_SET_MON_VALUE(rtc_tm->tm_mon) | 366 SUNXI_DATE_SET_YEAR_VALUE(rtc_tm->tm_year, 367 chip->data_year->mask); 368 369 if (is_leap_year(year)) 370 date |= SUNXI_LEAP_SET_VALUE(1, chip->data_year->leap_shift); 371 372 time = SUNXI_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) | 373 SUNXI_TIME_SET_MIN_VALUE(rtc_tm->tm_min) | 374 SUNXI_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour); 375 376 writel(0, chip->base + SUNXI_RTC_HMS); 377 writel(0, chip->base + SUNXI_RTC_YMD); 378 379 writel(time, chip->base + SUNXI_RTC_HMS); 380 381 /* 382 * After writing the RTC HH-MM-SS register, the 383 * SUNXI_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not 384 * be cleared until the real writing operation is finished 385 */ 386 387 if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL, 388 SUNXI_LOSC_CTRL_RTC_HMS_ACC, 50)) { 389 dev_err(dev, "Failed to set rtc time.\n"); 390 return -1; 391 } 392 393 writel(date, chip->base + SUNXI_RTC_YMD); 394 395 /* 396 * After writing the RTC YY-MM-DD register, the 397 * SUNXI_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not 398 * be cleared until the real writing operation is finished 399 */ 400 401 if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL, 402 SUNXI_LOSC_CTRL_RTC_YMD_ACC, 50)) { 403 dev_err(dev, "Failed to set rtc time.\n"); 404 return -1; 405 } 406 407 return 0; 408 } 409 410 static int sunxi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 411 { 412 struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); 413 414 if (!enabled) 415 sunxi_rtc_setaie(enabled, chip); 416 417 return 0; 418 } 419 420 static const struct rtc_class_ops sunxi_rtc_ops = { 421 .read_time = sunxi_rtc_gettime, 422 .set_time = sunxi_rtc_settime, 423 .read_alarm = sunxi_rtc_getalarm, 424 .set_alarm = sunxi_rtc_setalarm, 425 .alarm_irq_enable = sunxi_rtc_alarm_irq_enable 426 }; 427 428 static const struct of_device_id sunxi_rtc_dt_ids[] = { 429 { .compatible = "allwinner,sun4i-a10-rtc", .data = &data_year_param[0] }, 430 { .compatible = "allwinner,sun7i-a20-rtc", .data = &data_year_param[1] }, 431 { /* sentinel */ }, 432 }; 433 MODULE_DEVICE_TABLE(of, sunxi_rtc_dt_ids); 434 435 static int sunxi_rtc_probe(struct platform_device *pdev) 436 { 437 struct sunxi_rtc_dev *chip; 438 struct resource *res; 439 const struct of_device_id *of_id; 440 int ret; 441 442 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); 443 if (!chip) 444 return -ENOMEM; 445 446 platform_set_drvdata(pdev, chip); 447 chip->dev = &pdev->dev; 448 449 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 450 chip->base = devm_ioremap_resource(&pdev->dev, res); 451 if (IS_ERR(chip->base)) 452 return PTR_ERR(chip->base); 453 454 chip->irq = platform_get_irq(pdev, 0); 455 if (chip->irq < 0) { 456 dev_err(&pdev->dev, "No IRQ resource\n"); 457 return chip->irq; 458 } 459 ret = devm_request_irq(&pdev->dev, chip->irq, sunxi_rtc_alarmirq, 460 0, dev_name(&pdev->dev), chip); 461 if (ret) { 462 dev_err(&pdev->dev, "Could not request IRQ\n"); 463 return ret; 464 } 465 466 of_id = of_match_device(sunxi_rtc_dt_ids, &pdev->dev); 467 if (!of_id) { 468 dev_err(&pdev->dev, "Unable to setup RTC data\n"); 469 return -ENODEV; 470 } 471 chip->data_year = (struct sunxi_rtc_data_year *) of_id->data; 472 473 /* clear the alarm count value */ 474 writel(0, chip->base + SUNXI_ALRM_DHMS); 475 476 /* disable alarm, not generate irq pending */ 477 writel(0, chip->base + SUNXI_ALRM_EN); 478 479 /* disable alarm week/cnt irq, unset to cpu */ 480 writel(0, chip->base + SUNXI_ALRM_IRQ_EN); 481 482 /* clear alarm week/cnt irq pending */ 483 writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base + 484 SUNXI_ALRM_IRQ_STA); 485 486 chip->rtc = rtc_device_register("rtc-sunxi", &pdev->dev, 487 &sunxi_rtc_ops, THIS_MODULE); 488 if (IS_ERR(chip->rtc)) { 489 dev_err(&pdev->dev, "unable to register device\n"); 490 return PTR_ERR(chip->rtc); 491 } 492 493 dev_info(&pdev->dev, "RTC enabled\n"); 494 495 return 0; 496 } 497 498 static int sunxi_rtc_remove(struct platform_device *pdev) 499 { 500 struct sunxi_rtc_dev *chip = platform_get_drvdata(pdev); 501 502 rtc_device_unregister(chip->rtc); 503 504 return 0; 505 } 506 507 static struct platform_driver sunxi_rtc_driver = { 508 .probe = sunxi_rtc_probe, 509 .remove = sunxi_rtc_remove, 510 .driver = { 511 .name = "sunxi-rtc", 512 .of_match_table = sunxi_rtc_dt_ids, 513 }, 514 }; 515 516 module_platform_driver(sunxi_rtc_driver); 517 518 MODULE_DESCRIPTION("sunxi RTC driver"); 519 MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>"); 520 MODULE_LICENSE("GPL"); 521