1 /* 2 * ST M48T59 RTC driver 3 * 4 * Copyright (c) 2007 Wind River Systems, Inc. 5 * 6 * Author: Mark Zhan <rongkai.zhan@windriver.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/io.h> 17 #include <linux/device.h> 18 #include <linux/platform_device.h> 19 #include <linux/rtc.h> 20 #include <linux/rtc/m48t59.h> 21 #include <linux/bcd.h> 22 23 #ifndef NO_IRQ 24 #define NO_IRQ (-1) 25 #endif 26 27 #define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg)) 28 #define M48T59_WRITE(val, reg) \ 29 (pdata->write_byte(dev, pdata->offset + reg, val)) 30 31 #define M48T59_SET_BITS(mask, reg) \ 32 M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg)) 33 #define M48T59_CLEAR_BITS(mask, reg) \ 34 M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg)) 35 36 struct m48t59_private { 37 void __iomem *ioaddr; 38 int irq; 39 struct rtc_device *rtc; 40 spinlock_t lock; /* serialize the NVRAM and RTC access */ 41 }; 42 43 /* 44 * This is the generic access method when the chip is memory-mapped 45 */ 46 static void 47 m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val) 48 { 49 struct platform_device *pdev = to_platform_device(dev); 50 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 51 52 writeb(val, m48t59->ioaddr+ofs); 53 } 54 55 static u8 56 m48t59_mem_readb(struct device *dev, u32 ofs) 57 { 58 struct platform_device *pdev = to_platform_device(dev); 59 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 60 61 return readb(m48t59->ioaddr+ofs); 62 } 63 64 /* 65 * NOTE: M48T59 only uses BCD mode 66 */ 67 static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm) 68 { 69 struct platform_device *pdev = to_platform_device(dev); 70 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 71 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 72 unsigned long flags; 73 u8 val; 74 75 spin_lock_irqsave(&m48t59->lock, flags); 76 /* Issue the READ command */ 77 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); 78 79 tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); 80 /* tm_mon is 0-11 */ 81 tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; 82 tm->tm_mday = bcd2bin(M48T59_READ(M48T59_MDAY)); 83 84 val = M48T59_READ(M48T59_WDAY); 85 if ((pdata->type == M48T59RTC_TYPE_M48T59) && 86 (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) { 87 dev_dbg(dev, "Century bit is enabled\n"); 88 tm->tm_year += 100; /* one century */ 89 } 90 #ifdef CONFIG_SPARC 91 /* Sun SPARC machines count years since 1968 */ 92 tm->tm_year += 68; 93 #endif 94 95 tm->tm_wday = bcd2bin(val & 0x07); 96 tm->tm_hour = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F); 97 tm->tm_min = bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F); 98 tm->tm_sec = bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F); 99 100 /* Clear the READ bit */ 101 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); 102 spin_unlock_irqrestore(&m48t59->lock, flags); 103 104 dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n", 105 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 106 tm->tm_hour, tm->tm_min, tm->tm_sec); 107 return 0; 108 } 109 110 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm) 111 { 112 struct platform_device *pdev = to_platform_device(dev); 113 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 114 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 115 unsigned long flags; 116 u8 val = 0; 117 int year = tm->tm_year; 118 119 #ifdef CONFIG_SPARC 120 /* Sun SPARC machines count years since 1968 */ 121 year -= 68; 122 #endif 123 124 dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n", 125 year + 1900, tm->tm_mon, tm->tm_mday, 126 tm->tm_hour, tm->tm_min, tm->tm_sec); 127 128 if (year < 0) 129 return -EINVAL; 130 131 spin_lock_irqsave(&m48t59->lock, flags); 132 /* Issue the WRITE command */ 133 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 134 135 M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC); 136 M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN); 137 M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR); 138 M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY); 139 /* tm_mon is 0-11 */ 140 M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH); 141 M48T59_WRITE(bin2bcd(year % 100), M48T59_YEAR); 142 143 if (pdata->type == M48T59RTC_TYPE_M48T59 && (year / 100)) 144 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB); 145 val |= (bin2bcd(tm->tm_wday) & 0x07); 146 M48T59_WRITE(val, M48T59_WDAY); 147 148 /* Clear the WRITE bit */ 149 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 150 spin_unlock_irqrestore(&m48t59->lock, flags); 151 return 0; 152 } 153 154 /* 155 * Read alarm time and date in RTC 156 */ 157 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 158 { 159 struct platform_device *pdev = to_platform_device(dev); 160 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 161 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 162 struct rtc_time *tm = &alrm->time; 163 unsigned long flags; 164 u8 val; 165 166 /* If no irq, we don't support ALARM */ 167 if (m48t59->irq == NO_IRQ) 168 return -EIO; 169 170 spin_lock_irqsave(&m48t59->lock, flags); 171 /* Issue the READ command */ 172 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); 173 174 tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); 175 #ifdef CONFIG_SPARC 176 /* Sun SPARC machines count years since 1968 */ 177 tm->tm_year += 68; 178 #endif 179 /* tm_mon is 0-11 */ 180 tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; 181 182 val = M48T59_READ(M48T59_WDAY); 183 if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) 184 tm->tm_year += 100; /* one century */ 185 186 tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE)); 187 tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR)); 188 tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN)); 189 tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC)); 190 191 /* Clear the READ bit */ 192 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); 193 spin_unlock_irqrestore(&m48t59->lock, flags); 194 195 dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n", 196 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 197 tm->tm_hour, tm->tm_min, tm->tm_sec); 198 return 0; 199 } 200 201 /* 202 * Set alarm time and date in RTC 203 */ 204 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 205 { 206 struct platform_device *pdev = to_platform_device(dev); 207 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 208 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 209 struct rtc_time *tm = &alrm->time; 210 u8 mday, hour, min, sec; 211 unsigned long flags; 212 int year = tm->tm_year; 213 214 #ifdef CONFIG_SPARC 215 /* Sun SPARC machines count years since 1968 */ 216 year -= 68; 217 #endif 218 219 /* If no irq, we don't support ALARM */ 220 if (m48t59->irq == NO_IRQ) 221 return -EIO; 222 223 if (year < 0) 224 return -EINVAL; 225 226 /* 227 * 0xff means "always match" 228 */ 229 mday = tm->tm_mday; 230 mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff; 231 if (mday == 0xff) 232 mday = M48T59_READ(M48T59_MDAY); 233 234 hour = tm->tm_hour; 235 hour = (hour < 24) ? bin2bcd(hour) : 0x00; 236 237 min = tm->tm_min; 238 min = (min < 60) ? bin2bcd(min) : 0x00; 239 240 sec = tm->tm_sec; 241 sec = (sec < 60) ? bin2bcd(sec) : 0x00; 242 243 spin_lock_irqsave(&m48t59->lock, flags); 244 /* Issue the WRITE command */ 245 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 246 247 M48T59_WRITE(mday, M48T59_ALARM_DATE); 248 M48T59_WRITE(hour, M48T59_ALARM_HOUR); 249 M48T59_WRITE(min, M48T59_ALARM_MIN); 250 M48T59_WRITE(sec, M48T59_ALARM_SEC); 251 252 /* Clear the WRITE bit */ 253 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 254 spin_unlock_irqrestore(&m48t59->lock, flags); 255 256 dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n", 257 year + 1900, tm->tm_mon, tm->tm_mday, 258 tm->tm_hour, tm->tm_min, tm->tm_sec); 259 return 0; 260 } 261 262 /* 263 * Handle commands from user-space 264 */ 265 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd, 266 unsigned long arg) 267 { 268 struct platform_device *pdev = to_platform_device(dev); 269 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 270 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 271 unsigned long flags; 272 int ret = 0; 273 274 spin_lock_irqsave(&m48t59->lock, flags); 275 switch (cmd) { 276 case RTC_AIE_OFF: /* alarm interrupt off */ 277 M48T59_WRITE(0x00, M48T59_INTR); 278 break; 279 case RTC_AIE_ON: /* alarm interrupt on */ 280 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR); 281 break; 282 default: 283 ret = -ENOIOCTLCMD; 284 break; 285 } 286 spin_unlock_irqrestore(&m48t59->lock, flags); 287 288 return ret; 289 } 290 291 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq) 292 { 293 struct platform_device *pdev = to_platform_device(dev); 294 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 295 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 296 unsigned long flags; 297 u8 val; 298 299 spin_lock_irqsave(&m48t59->lock, flags); 300 val = M48T59_READ(M48T59_FLAGS); 301 spin_unlock_irqrestore(&m48t59->lock, flags); 302 303 seq_printf(seq, "battery\t\t: %s\n", 304 (val & M48T59_FLAGS_BF) ? "low" : "normal"); 305 return 0; 306 } 307 308 /* 309 * IRQ handler for the RTC 310 */ 311 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id) 312 { 313 struct device *dev = (struct device *)dev_id; 314 struct platform_device *pdev = to_platform_device(dev); 315 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 316 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 317 u8 event; 318 319 spin_lock(&m48t59->lock); 320 event = M48T59_READ(M48T59_FLAGS); 321 spin_unlock(&m48t59->lock); 322 323 if (event & M48T59_FLAGS_AF) { 324 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF)); 325 return IRQ_HANDLED; 326 } 327 328 return IRQ_NONE; 329 } 330 331 static const struct rtc_class_ops m48t59_rtc_ops = { 332 .ioctl = m48t59_rtc_ioctl, 333 .read_time = m48t59_rtc_read_time, 334 .set_time = m48t59_rtc_set_time, 335 .read_alarm = m48t59_rtc_readalarm, 336 .set_alarm = m48t59_rtc_setalarm, 337 .proc = m48t59_rtc_proc, 338 }; 339 340 static const struct rtc_class_ops m48t02_rtc_ops = { 341 .read_time = m48t59_rtc_read_time, 342 .set_time = m48t59_rtc_set_time, 343 }; 344 345 static ssize_t m48t59_nvram_read(struct kobject *kobj, 346 struct bin_attribute *bin_attr, 347 char *buf, loff_t pos, size_t size) 348 { 349 struct device *dev = container_of(kobj, struct device, kobj); 350 struct platform_device *pdev = to_platform_device(dev); 351 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 352 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 353 ssize_t cnt = 0; 354 unsigned long flags; 355 356 for (; size > 0 && pos < pdata->offset; cnt++, size--) { 357 spin_lock_irqsave(&m48t59->lock, flags); 358 *buf++ = M48T59_READ(cnt); 359 spin_unlock_irqrestore(&m48t59->lock, flags); 360 } 361 362 return cnt; 363 } 364 365 static ssize_t m48t59_nvram_write(struct kobject *kobj, 366 struct bin_attribute *bin_attr, 367 char *buf, loff_t pos, size_t size) 368 { 369 struct device *dev = container_of(kobj, struct device, kobj); 370 struct platform_device *pdev = to_platform_device(dev); 371 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 372 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 373 ssize_t cnt = 0; 374 unsigned long flags; 375 376 for (; size > 0 && pos < pdata->offset; cnt++, size--) { 377 spin_lock_irqsave(&m48t59->lock, flags); 378 M48T59_WRITE(*buf++, cnt); 379 spin_unlock_irqrestore(&m48t59->lock, flags); 380 } 381 382 return cnt; 383 } 384 385 static struct bin_attribute m48t59_nvram_attr = { 386 .attr = { 387 .name = "nvram", 388 .mode = S_IRUGO | S_IWUSR, 389 }, 390 .read = m48t59_nvram_read, 391 .write = m48t59_nvram_write, 392 }; 393 394 static int __devinit m48t59_rtc_probe(struct platform_device *pdev) 395 { 396 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 397 struct m48t59_private *m48t59 = NULL; 398 struct resource *res; 399 int ret = -ENOMEM; 400 char *name; 401 const struct rtc_class_ops *ops; 402 403 /* This chip could be memory-mapped or I/O-mapped */ 404 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 405 if (!res) { 406 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 407 if (!res) 408 return -EINVAL; 409 } 410 411 if (res->flags & IORESOURCE_IO) { 412 /* If we are I/O-mapped, the platform should provide 413 * the operations accessing chip registers. 414 */ 415 if (!pdata || !pdata->write_byte || !pdata->read_byte) 416 return -EINVAL; 417 } else if (res->flags & IORESOURCE_MEM) { 418 /* we are memory-mapped */ 419 if (!pdata) { 420 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 421 if (!pdata) 422 return -ENOMEM; 423 /* Ensure we only kmalloc platform data once */ 424 pdev->dev.platform_data = pdata; 425 } 426 if (!pdata->type) 427 pdata->type = M48T59RTC_TYPE_M48T59; 428 429 /* Try to use the generic memory read/write ops */ 430 if (!pdata->write_byte) 431 pdata->write_byte = m48t59_mem_writeb; 432 if (!pdata->read_byte) 433 pdata->read_byte = m48t59_mem_readb; 434 } 435 436 m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL); 437 if (!m48t59) 438 return -ENOMEM; 439 440 m48t59->ioaddr = pdata->ioaddr; 441 442 if (!m48t59->ioaddr) { 443 /* ioaddr not mapped externally */ 444 m48t59->ioaddr = ioremap(res->start, res->end - res->start + 1); 445 if (!m48t59->ioaddr) 446 goto out; 447 } 448 449 /* Try to get irq number. We also can work in 450 * the mode without IRQ. 451 */ 452 m48t59->irq = platform_get_irq(pdev, 0); 453 if (m48t59->irq <= 0) 454 m48t59->irq = NO_IRQ; 455 456 if (m48t59->irq != NO_IRQ) { 457 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt, 458 IRQF_SHARED, "rtc-m48t59", &pdev->dev); 459 if (ret) 460 goto out; 461 } 462 switch (pdata->type) { 463 case M48T59RTC_TYPE_M48T59: 464 name = "m48t59"; 465 ops = &m48t59_rtc_ops; 466 pdata->offset = 0x1ff0; 467 break; 468 case M48T59RTC_TYPE_M48T02: 469 name = "m48t02"; 470 ops = &m48t02_rtc_ops; 471 pdata->offset = 0x7f0; 472 break; 473 case M48T59RTC_TYPE_M48T08: 474 name = "m48t08"; 475 ops = &m48t02_rtc_ops; 476 pdata->offset = 0x1ff0; 477 break; 478 default: 479 dev_err(&pdev->dev, "Unknown RTC type\n"); 480 ret = -ENODEV; 481 goto out; 482 } 483 484 m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE); 485 if (IS_ERR(m48t59->rtc)) { 486 ret = PTR_ERR(m48t59->rtc); 487 goto out; 488 } 489 490 m48t59_nvram_attr.size = pdata->offset; 491 492 ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 493 if (ret) 494 goto out; 495 496 spin_lock_init(&m48t59->lock); 497 platform_set_drvdata(pdev, m48t59); 498 return 0; 499 500 out: 501 if (!IS_ERR(m48t59->rtc)) 502 rtc_device_unregister(m48t59->rtc); 503 if (m48t59->irq != NO_IRQ) 504 free_irq(m48t59->irq, &pdev->dev); 505 if (m48t59->ioaddr) 506 iounmap(m48t59->ioaddr); 507 if (m48t59) 508 kfree(m48t59); 509 return ret; 510 } 511 512 static int __devexit m48t59_rtc_remove(struct platform_device *pdev) 513 { 514 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 515 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 516 517 sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 518 if (!IS_ERR(m48t59->rtc)) 519 rtc_device_unregister(m48t59->rtc); 520 if (m48t59->ioaddr && !pdata->ioaddr) 521 iounmap(m48t59->ioaddr); 522 if (m48t59->irq != NO_IRQ) 523 free_irq(m48t59->irq, &pdev->dev); 524 platform_set_drvdata(pdev, NULL); 525 kfree(m48t59); 526 return 0; 527 } 528 529 /* work with hotplug and coldplug */ 530 MODULE_ALIAS("platform:rtc-m48t59"); 531 532 static struct platform_driver m48t59_rtc_driver = { 533 .driver = { 534 .name = "rtc-m48t59", 535 .owner = THIS_MODULE, 536 }, 537 .probe = m48t59_rtc_probe, 538 .remove = __devexit_p(m48t59_rtc_remove), 539 }; 540 541 static int __init m48t59_rtc_init(void) 542 { 543 return platform_driver_register(&m48t59_rtc_driver); 544 } 545 546 static void __exit m48t59_rtc_exit(void) 547 { 548 platform_driver_unregister(&m48t59_rtc_driver); 549 } 550 551 module_init(m48t59_rtc_init); 552 module_exit(m48t59_rtc_exit); 553 554 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>"); 555 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver"); 556 MODULE_LICENSE("GPL"); 557