1 /* 2 * Real Time Clock interface for XScale PXA27x and PXA3xx 3 * 4 * Copyright (C) 2008 Robert Jarzmik 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, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 * 20 */ 21 22 #include <linux/init.h> 23 #include <linux/platform_device.h> 24 #include <linux/module.h> 25 #include <linux/rtc.h> 26 #include <linux/seq_file.h> 27 #include <linux/interrupt.h> 28 #include <linux/io.h> 29 #include <linux/slab.h> 30 31 #include <mach/hardware.h> 32 33 #define TIMER_FREQ CLOCK_TICK_RATE 34 #define RTC_DEF_DIVIDER (32768 - 1) 35 #define RTC_DEF_TRIM 0 36 #define MAXFREQ_PERIODIC 1000 37 38 /* 39 * PXA Registers and bits definitions 40 */ 41 #define RTSR_PICE (1 << 15) /* Periodic interrupt count enable */ 42 #define RTSR_PIALE (1 << 14) /* Periodic interrupt Alarm enable */ 43 #define RTSR_PIAL (1 << 13) /* Periodic interrupt detected */ 44 #define RTSR_SWALE2 (1 << 11) /* RTC stopwatch alarm2 enable */ 45 #define RTSR_SWAL2 (1 << 10) /* RTC stopwatch alarm2 detected */ 46 #define RTSR_SWALE1 (1 << 9) /* RTC stopwatch alarm1 enable */ 47 #define RTSR_SWAL1 (1 << 8) /* RTC stopwatch alarm1 detected */ 48 #define RTSR_RDALE2 (1 << 7) /* RTC alarm2 enable */ 49 #define RTSR_RDAL2 (1 << 6) /* RTC alarm2 detected */ 50 #define RTSR_RDALE1 (1 << 5) /* RTC alarm1 enable */ 51 #define RTSR_RDAL1 (1 << 4) /* RTC alarm1 detected */ 52 #define RTSR_HZE (1 << 3) /* HZ interrupt enable */ 53 #define RTSR_ALE (1 << 2) /* RTC alarm interrupt enable */ 54 #define RTSR_HZ (1 << 1) /* HZ rising-edge detected */ 55 #define RTSR_AL (1 << 0) /* RTC alarm detected */ 56 #define RTSR_TRIG_MASK (RTSR_AL | RTSR_HZ | RTSR_RDAL1 | RTSR_RDAL2\ 57 | RTSR_SWAL1 | RTSR_SWAL2) 58 #define RYxR_YEAR_S 9 59 #define RYxR_YEAR_MASK (0xfff << RYxR_YEAR_S) 60 #define RYxR_MONTH_S 5 61 #define RYxR_MONTH_MASK (0xf << RYxR_MONTH_S) 62 #define RYxR_DAY_MASK 0x1f 63 #define RDxR_HOUR_S 12 64 #define RDxR_HOUR_MASK (0x1f << RDxR_HOUR_S) 65 #define RDxR_MIN_S 6 66 #define RDxR_MIN_MASK (0x3f << RDxR_MIN_S) 67 #define RDxR_SEC_MASK 0x3f 68 69 #define RTSR 0x08 70 #define RTTR 0x0c 71 #define RDCR 0x10 72 #define RYCR 0x14 73 #define RDAR1 0x18 74 #define RYAR1 0x1c 75 #define RTCPICR 0x34 76 #define PIAR 0x38 77 78 #define rtc_readl(pxa_rtc, reg) \ 79 __raw_readl((pxa_rtc)->base + (reg)) 80 #define rtc_writel(pxa_rtc, reg, value) \ 81 __raw_writel((value), (pxa_rtc)->base + (reg)) 82 83 struct pxa_rtc { 84 struct resource *ress; 85 void __iomem *base; 86 int irq_1Hz; 87 int irq_Alrm; 88 struct rtc_device *rtc; 89 spinlock_t lock; /* Protects this structure */ 90 }; 91 92 static u32 ryxr_calc(struct rtc_time *tm) 93 { 94 return ((tm->tm_year + 1900) << RYxR_YEAR_S) 95 | ((tm->tm_mon + 1) << RYxR_MONTH_S) 96 | tm->tm_mday; 97 } 98 99 static u32 rdxr_calc(struct rtc_time *tm) 100 { 101 return (tm->tm_hour << RDxR_HOUR_S) | (tm->tm_min << RDxR_MIN_S) 102 | tm->tm_sec; 103 } 104 105 static void tm_calc(u32 rycr, u32 rdcr, struct rtc_time *tm) 106 { 107 tm->tm_year = ((rycr & RYxR_YEAR_MASK) >> RYxR_YEAR_S) - 1900; 108 tm->tm_mon = (((rycr & RYxR_MONTH_MASK) >> RYxR_MONTH_S)) - 1; 109 tm->tm_mday = (rycr & RYxR_DAY_MASK); 110 tm->tm_hour = (rdcr & RDxR_HOUR_MASK) >> RDxR_HOUR_S; 111 tm->tm_min = (rdcr & RDxR_MIN_MASK) >> RDxR_MIN_S; 112 tm->tm_sec = rdcr & RDxR_SEC_MASK; 113 } 114 115 static void rtsr_clear_bits(struct pxa_rtc *pxa_rtc, u32 mask) 116 { 117 u32 rtsr; 118 119 rtsr = rtc_readl(pxa_rtc, RTSR); 120 rtsr &= ~RTSR_TRIG_MASK; 121 rtsr &= ~mask; 122 rtc_writel(pxa_rtc, RTSR, rtsr); 123 } 124 125 static void rtsr_set_bits(struct pxa_rtc *pxa_rtc, u32 mask) 126 { 127 u32 rtsr; 128 129 rtsr = rtc_readl(pxa_rtc, RTSR); 130 rtsr &= ~RTSR_TRIG_MASK; 131 rtsr |= mask; 132 rtc_writel(pxa_rtc, RTSR, rtsr); 133 } 134 135 static irqreturn_t pxa_rtc_irq(int irq, void *dev_id) 136 { 137 struct platform_device *pdev = to_platform_device(dev_id); 138 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev); 139 u32 rtsr; 140 unsigned long events = 0; 141 142 spin_lock(&pxa_rtc->lock); 143 144 /* clear interrupt sources */ 145 rtsr = rtc_readl(pxa_rtc, RTSR); 146 rtc_writel(pxa_rtc, RTSR, rtsr); 147 148 /* temporary disable rtc interrupts */ 149 rtsr_clear_bits(pxa_rtc, RTSR_RDALE1 | RTSR_PIALE | RTSR_HZE); 150 151 /* clear alarm interrupt if it has occurred */ 152 if (rtsr & RTSR_RDAL1) 153 rtsr &= ~RTSR_RDALE1; 154 155 /* update irq data & counter */ 156 if (rtsr & RTSR_RDAL1) 157 events |= RTC_AF | RTC_IRQF; 158 if (rtsr & RTSR_HZ) 159 events |= RTC_UF | RTC_IRQF; 160 if (rtsr & RTSR_PIAL) 161 events |= RTC_PF | RTC_IRQF; 162 163 rtc_update_irq(pxa_rtc->rtc, 1, events); 164 165 /* enable back rtc interrupts */ 166 rtc_writel(pxa_rtc, RTSR, rtsr & ~RTSR_TRIG_MASK); 167 168 spin_unlock(&pxa_rtc->lock); 169 return IRQ_HANDLED; 170 } 171 172 static int pxa_rtc_open(struct device *dev) 173 { 174 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 175 int ret; 176 177 ret = request_irq(pxa_rtc->irq_1Hz, pxa_rtc_irq, IRQF_DISABLED, 178 "rtc 1Hz", dev); 179 if (ret < 0) { 180 dev_err(dev, "can't get irq %i, err %d\n", pxa_rtc->irq_1Hz, 181 ret); 182 goto err_irq_1Hz; 183 } 184 ret = request_irq(pxa_rtc->irq_Alrm, pxa_rtc_irq, IRQF_DISABLED, 185 "rtc Alrm", dev); 186 if (ret < 0) { 187 dev_err(dev, "can't get irq %i, err %d\n", pxa_rtc->irq_Alrm, 188 ret); 189 goto err_irq_Alrm; 190 } 191 192 return 0; 193 194 err_irq_Alrm: 195 free_irq(pxa_rtc->irq_1Hz, dev); 196 err_irq_1Hz: 197 return ret; 198 } 199 200 static void pxa_rtc_release(struct device *dev) 201 { 202 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 203 204 spin_lock_irq(&pxa_rtc->lock); 205 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE); 206 spin_unlock_irq(&pxa_rtc->lock); 207 208 free_irq(pxa_rtc->irq_Alrm, dev); 209 free_irq(pxa_rtc->irq_1Hz, dev); 210 } 211 212 static int pxa_periodic_irq_set_freq(struct device *dev, int freq) 213 { 214 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 215 int period_ms; 216 217 if (freq < 1 || freq > MAXFREQ_PERIODIC) 218 return -EINVAL; 219 220 period_ms = 1000 / freq; 221 rtc_writel(pxa_rtc, PIAR, period_ms); 222 223 return 0; 224 } 225 226 static int pxa_periodic_irq_set_state(struct device *dev, int enabled) 227 { 228 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 229 230 if (enabled) 231 rtsr_set_bits(pxa_rtc, RTSR_PIALE | RTSR_PICE); 232 else 233 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_PICE); 234 235 return 0; 236 } 237 238 static int pxa_alarm_irq_enable(struct device *dev, unsigned int enabled) 239 { 240 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 241 242 spin_lock_irq(&pxa_rtc->lock); 243 244 if (enabled) 245 rtsr_set_bits(pxa_rtc, RTSR_RDALE1); 246 else 247 rtsr_clear_bits(pxa_rtc, RTSR_RDALE1); 248 249 spin_unlock_irq(&pxa_rtc->lock); 250 return 0; 251 } 252 253 static int pxa_update_irq_enable(struct device *dev, unsigned int enabled) 254 { 255 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 256 257 spin_lock_irq(&pxa_rtc->lock); 258 259 if (enabled) 260 rtsr_set_bits(pxa_rtc, RTSR_HZE); 261 else 262 rtsr_clear_bits(pxa_rtc, RTSR_HZE); 263 264 spin_unlock_irq(&pxa_rtc->lock); 265 return 0; 266 } 267 268 static int pxa_rtc_read_time(struct device *dev, struct rtc_time *tm) 269 { 270 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 271 u32 rycr, rdcr; 272 273 rycr = rtc_readl(pxa_rtc, RYCR); 274 rdcr = rtc_readl(pxa_rtc, RDCR); 275 276 tm_calc(rycr, rdcr, tm); 277 return 0; 278 } 279 280 static int pxa_rtc_set_time(struct device *dev, struct rtc_time *tm) 281 { 282 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 283 284 rtc_writel(pxa_rtc, RYCR, ryxr_calc(tm)); 285 rtc_writel(pxa_rtc, RDCR, rdxr_calc(tm)); 286 287 return 0; 288 } 289 290 static int pxa_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 291 { 292 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 293 u32 rtsr, ryar, rdar; 294 295 ryar = rtc_readl(pxa_rtc, RYAR1); 296 rdar = rtc_readl(pxa_rtc, RDAR1); 297 tm_calc(ryar, rdar, &alrm->time); 298 299 rtsr = rtc_readl(pxa_rtc, RTSR); 300 alrm->enabled = (rtsr & RTSR_RDALE1) ? 1 : 0; 301 alrm->pending = (rtsr & RTSR_RDAL1) ? 1 : 0; 302 return 0; 303 } 304 305 static int pxa_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 306 { 307 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 308 u32 rtsr; 309 310 spin_lock_irq(&pxa_rtc->lock); 311 312 rtc_writel(pxa_rtc, RYAR1, ryxr_calc(&alrm->time)); 313 rtc_writel(pxa_rtc, RDAR1, rdxr_calc(&alrm->time)); 314 315 rtsr = rtc_readl(pxa_rtc, RTSR); 316 if (alrm->enabled) 317 rtsr |= RTSR_RDALE1; 318 else 319 rtsr &= ~RTSR_RDALE1; 320 rtc_writel(pxa_rtc, RTSR, rtsr); 321 322 spin_unlock_irq(&pxa_rtc->lock); 323 324 return 0; 325 } 326 327 static int pxa_rtc_proc(struct device *dev, struct seq_file *seq) 328 { 329 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 330 331 seq_printf(seq, "trim/divider\t: 0x%08x\n", rtc_readl(pxa_rtc, RTTR)); 332 seq_printf(seq, "update_IRQ\t: %s\n", 333 (rtc_readl(pxa_rtc, RTSR) & RTSR_HZE) ? "yes" : "no"); 334 seq_printf(seq, "periodic_IRQ\t: %s\n", 335 (rtc_readl(pxa_rtc, RTSR) & RTSR_PIALE) ? "yes" : "no"); 336 seq_printf(seq, "periodic_freq\t: %u\n", rtc_readl(pxa_rtc, PIAR)); 337 338 return 0; 339 } 340 341 static const struct rtc_class_ops pxa_rtc_ops = { 342 .open = pxa_rtc_open, 343 .release = pxa_rtc_release, 344 .read_time = pxa_rtc_read_time, 345 .set_time = pxa_rtc_set_time, 346 .read_alarm = pxa_rtc_read_alarm, 347 .set_alarm = pxa_rtc_set_alarm, 348 .alarm_irq_enable = pxa_alarm_irq_enable, 349 .update_irq_enable = pxa_update_irq_enable, 350 .proc = pxa_rtc_proc, 351 .irq_set_state = pxa_periodic_irq_set_state, 352 .irq_set_freq = pxa_periodic_irq_set_freq, 353 }; 354 355 static int __init pxa_rtc_probe(struct platform_device *pdev) 356 { 357 struct device *dev = &pdev->dev; 358 struct pxa_rtc *pxa_rtc; 359 int ret; 360 u32 rttr; 361 362 pxa_rtc = kzalloc(sizeof(struct pxa_rtc), GFP_KERNEL); 363 if (!pxa_rtc) 364 return -ENOMEM; 365 366 spin_lock_init(&pxa_rtc->lock); 367 platform_set_drvdata(pdev, pxa_rtc); 368 369 ret = -ENXIO; 370 pxa_rtc->ress = platform_get_resource(pdev, IORESOURCE_MEM, 0); 371 if (!pxa_rtc->ress) { 372 dev_err(dev, "No I/O memory resource defined\n"); 373 goto err_ress; 374 } 375 376 pxa_rtc->irq_1Hz = platform_get_irq(pdev, 0); 377 if (pxa_rtc->irq_1Hz < 0) { 378 dev_err(dev, "No 1Hz IRQ resource defined\n"); 379 goto err_ress; 380 } 381 pxa_rtc->irq_Alrm = platform_get_irq(pdev, 1); 382 if (pxa_rtc->irq_Alrm < 0) { 383 dev_err(dev, "No alarm IRQ resource defined\n"); 384 goto err_ress; 385 } 386 387 ret = -ENOMEM; 388 pxa_rtc->base = ioremap(pxa_rtc->ress->start, 389 resource_size(pxa_rtc->ress)); 390 if (!pxa_rtc->base) { 391 dev_err(&pdev->dev, "Unable to map pxa RTC I/O memory\n"); 392 goto err_map; 393 } 394 395 /* 396 * If the clock divider is uninitialized then reset it to the 397 * default value to get the 1Hz clock. 398 */ 399 if (rtc_readl(pxa_rtc, RTTR) == 0) { 400 rttr = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16); 401 rtc_writel(pxa_rtc, RTTR, rttr); 402 dev_warn(dev, "warning: initializing default clock" 403 " divider/trim value\n"); 404 } 405 406 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE); 407 408 pxa_rtc->rtc = rtc_device_register("pxa-rtc", &pdev->dev, &pxa_rtc_ops, 409 THIS_MODULE); 410 ret = PTR_ERR(pxa_rtc->rtc); 411 if (IS_ERR(pxa_rtc->rtc)) { 412 dev_err(dev, "Failed to register RTC device -> %d\n", ret); 413 goto err_rtc_reg; 414 } 415 416 device_init_wakeup(dev, 1); 417 418 return 0; 419 420 err_rtc_reg: 421 iounmap(pxa_rtc->base); 422 err_ress: 423 err_map: 424 kfree(pxa_rtc); 425 return ret; 426 } 427 428 static int __exit pxa_rtc_remove(struct platform_device *pdev) 429 { 430 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev); 431 432 rtc_device_unregister(pxa_rtc->rtc); 433 434 spin_lock_irq(&pxa_rtc->lock); 435 iounmap(pxa_rtc->base); 436 spin_unlock_irq(&pxa_rtc->lock); 437 438 kfree(pxa_rtc); 439 440 return 0; 441 } 442 443 #ifdef CONFIG_PM 444 static int pxa_rtc_suspend(struct device *dev) 445 { 446 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 447 448 if (device_may_wakeup(dev)) 449 enable_irq_wake(pxa_rtc->irq_Alrm); 450 return 0; 451 } 452 453 static int pxa_rtc_resume(struct device *dev) 454 { 455 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev); 456 457 if (device_may_wakeup(dev)) 458 disable_irq_wake(pxa_rtc->irq_Alrm); 459 return 0; 460 } 461 462 static const struct dev_pm_ops pxa_rtc_pm_ops = { 463 .suspend = pxa_rtc_suspend, 464 .resume = pxa_rtc_resume, 465 }; 466 #endif 467 468 static struct platform_driver pxa_rtc_driver = { 469 .remove = __exit_p(pxa_rtc_remove), 470 .driver = { 471 .name = "pxa-rtc", 472 #ifdef CONFIG_PM 473 .pm = &pxa_rtc_pm_ops, 474 #endif 475 }, 476 }; 477 478 static int __init pxa_rtc_init(void) 479 { 480 if (cpu_is_pxa27x() || cpu_is_pxa3xx()) 481 return platform_driver_probe(&pxa_rtc_driver, pxa_rtc_probe); 482 483 return -ENODEV; 484 } 485 486 static void __exit pxa_rtc_exit(void) 487 { 488 platform_driver_unregister(&pxa_rtc_driver); 489 } 490 491 module_init(pxa_rtc_init); 492 module_exit(pxa_rtc_exit); 493 494 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>"); 495 MODULE_DESCRIPTION("PXA27x/PXA3xx Realtime Clock Driver (RTC)"); 496 MODULE_LICENSE("GPL"); 497 MODULE_ALIAS("platform:pxa-rtc"); 498