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 #include <linux/slab.h> 23 24 #ifndef NO_IRQ 25 #define NO_IRQ (-1) 26 #endif 27 28 #define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg)) 29 #define M48T59_WRITE(val, reg) \ 30 (pdata->write_byte(dev, pdata->offset + reg, val)) 31 32 #define M48T59_SET_BITS(mask, reg) \ 33 M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg)) 34 #define M48T59_CLEAR_BITS(mask, reg) \ 35 M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg)) 36 37 struct m48t59_private { 38 void __iomem *ioaddr; 39 int irq; 40 struct rtc_device *rtc; 41 spinlock_t lock; /* serialize the NVRAM and RTC access */ 42 }; 43 44 /* 45 * This is the generic access method when the chip is memory-mapped 46 */ 47 static void 48 m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val) 49 { 50 struct platform_device *pdev = to_platform_device(dev); 51 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 52 53 writeb(val, m48t59->ioaddr+ofs); 54 } 55 56 static u8 57 m48t59_mem_readb(struct device *dev, u32 ofs) 58 { 59 struct platform_device *pdev = to_platform_device(dev); 60 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 61 62 return readb(m48t59->ioaddr+ofs); 63 } 64 65 /* 66 * NOTE: M48T59 only uses BCD mode 67 */ 68 static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm) 69 { 70 struct platform_device *pdev = to_platform_device(dev); 71 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 72 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 73 unsigned long flags; 74 u8 val; 75 76 spin_lock_irqsave(&m48t59->lock, flags); 77 /* Issue the READ command */ 78 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); 79 80 tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); 81 /* tm_mon is 0-11 */ 82 tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; 83 tm->tm_mday = bcd2bin(M48T59_READ(M48T59_MDAY)); 84 85 val = M48T59_READ(M48T59_WDAY); 86 if ((pdata->type == M48T59RTC_TYPE_M48T59) && 87 (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) { 88 dev_dbg(dev, "Century bit is enabled\n"); 89 tm->tm_year += 100; /* one century */ 90 } 91 #ifdef CONFIG_SPARC 92 /* Sun SPARC machines count years since 1968 */ 93 tm->tm_year += 68; 94 #endif 95 96 tm->tm_wday = bcd2bin(val & 0x07); 97 tm->tm_hour = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F); 98 tm->tm_min = bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F); 99 tm->tm_sec = bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F); 100 101 /* Clear the READ bit */ 102 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); 103 spin_unlock_irqrestore(&m48t59->lock, flags); 104 105 dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n", 106 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 107 tm->tm_hour, tm->tm_min, tm->tm_sec); 108 return rtc_valid_tm(tm); 109 } 110 111 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm) 112 { 113 struct platform_device *pdev = to_platform_device(dev); 114 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 115 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 116 unsigned long flags; 117 u8 val = 0; 118 int year = tm->tm_year; 119 120 #ifdef CONFIG_SPARC 121 /* Sun SPARC machines count years since 1968 */ 122 year -= 68; 123 #endif 124 125 dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n", 126 year + 1900, tm->tm_mon, tm->tm_mday, 127 tm->tm_hour, tm->tm_min, tm->tm_sec); 128 129 if (year < 0) 130 return -EINVAL; 131 132 spin_lock_irqsave(&m48t59->lock, flags); 133 /* Issue the WRITE command */ 134 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 135 136 M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC); 137 M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN); 138 M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR); 139 M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY); 140 /* tm_mon is 0-11 */ 141 M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH); 142 M48T59_WRITE(bin2bcd(year % 100), M48T59_YEAR); 143 144 if (pdata->type == M48T59RTC_TYPE_M48T59 && (year / 100)) 145 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB); 146 val |= (bin2bcd(tm->tm_wday) & 0x07); 147 M48T59_WRITE(val, M48T59_WDAY); 148 149 /* Clear the WRITE bit */ 150 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 151 spin_unlock_irqrestore(&m48t59->lock, flags); 152 return 0; 153 } 154 155 /* 156 * Read alarm time and date in RTC 157 */ 158 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 159 { 160 struct platform_device *pdev = to_platform_device(dev); 161 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 162 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 163 struct rtc_time *tm = &alrm->time; 164 unsigned long flags; 165 u8 val; 166 167 /* If no irq, we don't support ALARM */ 168 if (m48t59->irq == NO_IRQ) 169 return -EIO; 170 171 spin_lock_irqsave(&m48t59->lock, flags); 172 /* Issue the READ command */ 173 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); 174 175 tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); 176 #ifdef CONFIG_SPARC 177 /* Sun SPARC machines count years since 1968 */ 178 tm->tm_year += 68; 179 #endif 180 /* tm_mon is 0-11 */ 181 tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; 182 183 val = M48T59_READ(M48T59_WDAY); 184 if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) 185 tm->tm_year += 100; /* one century */ 186 187 tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE)); 188 tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR)); 189 tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN)); 190 tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC)); 191 192 /* Clear the READ bit */ 193 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); 194 spin_unlock_irqrestore(&m48t59->lock, flags); 195 196 dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n", 197 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 198 tm->tm_hour, tm->tm_min, tm->tm_sec); 199 return rtc_valid_tm(tm); 200 } 201 202 /* 203 * Set alarm time and date in RTC 204 */ 205 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 206 { 207 struct platform_device *pdev = to_platform_device(dev); 208 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 209 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 210 struct rtc_time *tm = &alrm->time; 211 u8 mday, hour, min, sec; 212 unsigned long flags; 213 int year = tm->tm_year; 214 215 #ifdef CONFIG_SPARC 216 /* Sun SPARC machines count years since 1968 */ 217 year -= 68; 218 #endif 219 220 /* If no irq, we don't support ALARM */ 221 if (m48t59->irq == NO_IRQ) 222 return -EIO; 223 224 if (year < 0) 225 return -EINVAL; 226 227 /* 228 * 0xff means "always match" 229 */ 230 mday = tm->tm_mday; 231 mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff; 232 if (mday == 0xff) 233 mday = M48T59_READ(M48T59_MDAY); 234 235 hour = tm->tm_hour; 236 hour = (hour < 24) ? bin2bcd(hour) : 0x00; 237 238 min = tm->tm_min; 239 min = (min < 60) ? bin2bcd(min) : 0x00; 240 241 sec = tm->tm_sec; 242 sec = (sec < 60) ? bin2bcd(sec) : 0x00; 243 244 spin_lock_irqsave(&m48t59->lock, flags); 245 /* Issue the WRITE command */ 246 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 247 248 M48T59_WRITE(mday, M48T59_ALARM_DATE); 249 M48T59_WRITE(hour, M48T59_ALARM_HOUR); 250 M48T59_WRITE(min, M48T59_ALARM_MIN); 251 M48T59_WRITE(sec, M48T59_ALARM_SEC); 252 253 /* Clear the WRITE bit */ 254 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 255 spin_unlock_irqrestore(&m48t59->lock, flags); 256 257 dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n", 258 year + 1900, tm->tm_mon, tm->tm_mday, 259 tm->tm_hour, tm->tm_min, tm->tm_sec); 260 return 0; 261 } 262 263 /* 264 * Handle commands from user-space 265 */ 266 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd, 267 unsigned long arg) 268 { 269 struct platform_device *pdev = to_platform_device(dev); 270 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 271 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 272 unsigned long flags; 273 int ret = 0; 274 275 spin_lock_irqsave(&m48t59->lock, flags); 276 switch (cmd) { 277 case RTC_AIE_OFF: /* alarm interrupt off */ 278 M48T59_WRITE(0x00, M48T59_INTR); 279 break; 280 case RTC_AIE_ON: /* alarm interrupt on */ 281 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR); 282 break; 283 default: 284 ret = -ENOIOCTLCMD; 285 break; 286 } 287 spin_unlock_irqrestore(&m48t59->lock, flags); 288 289 return ret; 290 } 291 292 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq) 293 { 294 struct platform_device *pdev = to_platform_device(dev); 295 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 296 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 297 unsigned long flags; 298 u8 val; 299 300 spin_lock_irqsave(&m48t59->lock, flags); 301 val = M48T59_READ(M48T59_FLAGS); 302 spin_unlock_irqrestore(&m48t59->lock, flags); 303 304 seq_printf(seq, "battery\t\t: %s\n", 305 (val & M48T59_FLAGS_BF) ? "low" : "normal"); 306 return 0; 307 } 308 309 /* 310 * IRQ handler for the RTC 311 */ 312 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id) 313 { 314 struct device *dev = (struct device *)dev_id; 315 struct platform_device *pdev = to_platform_device(dev); 316 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 317 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 318 u8 event; 319 320 spin_lock(&m48t59->lock); 321 event = M48T59_READ(M48T59_FLAGS); 322 spin_unlock(&m48t59->lock); 323 324 if (event & M48T59_FLAGS_AF) { 325 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF)); 326 return IRQ_HANDLED; 327 } 328 329 return IRQ_NONE; 330 } 331 332 static const struct rtc_class_ops m48t59_rtc_ops = { 333 .ioctl = m48t59_rtc_ioctl, 334 .read_time = m48t59_rtc_read_time, 335 .set_time = m48t59_rtc_set_time, 336 .read_alarm = m48t59_rtc_readalarm, 337 .set_alarm = m48t59_rtc_setalarm, 338 .proc = m48t59_rtc_proc, 339 }; 340 341 static const struct rtc_class_ops m48t02_rtc_ops = { 342 .read_time = m48t59_rtc_read_time, 343 .set_time = m48t59_rtc_set_time, 344 }; 345 346 static ssize_t m48t59_nvram_read(struct file *filp, struct kobject *kobj, 347 struct bin_attribute *bin_attr, 348 char *buf, loff_t pos, size_t size) 349 { 350 struct device *dev = container_of(kobj, struct device, kobj); 351 struct platform_device *pdev = to_platform_device(dev); 352 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 353 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 354 ssize_t cnt = 0; 355 unsigned long flags; 356 357 for (; size > 0 && pos < pdata->offset; cnt++, size--) { 358 spin_lock_irqsave(&m48t59->lock, flags); 359 *buf++ = M48T59_READ(cnt); 360 spin_unlock_irqrestore(&m48t59->lock, flags); 361 } 362 363 return cnt; 364 } 365 366 static ssize_t m48t59_nvram_write(struct file *filp, struct kobject *kobj, 367 struct bin_attribute *bin_attr, 368 char *buf, loff_t pos, size_t size) 369 { 370 struct device *dev = container_of(kobj, struct device, kobj); 371 struct platform_device *pdev = to_platform_device(dev); 372 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 373 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 374 ssize_t cnt = 0; 375 unsigned long flags; 376 377 for (; size > 0 && pos < pdata->offset; cnt++, size--) { 378 spin_lock_irqsave(&m48t59->lock, flags); 379 M48T59_WRITE(*buf++, cnt); 380 spin_unlock_irqrestore(&m48t59->lock, flags); 381 } 382 383 return cnt; 384 } 385 386 static struct bin_attribute m48t59_nvram_attr = { 387 .attr = { 388 .name = "nvram", 389 .mode = S_IRUGO | S_IWUSR, 390 }, 391 .read = m48t59_nvram_read, 392 .write = m48t59_nvram_write, 393 }; 394 395 static int __devinit m48t59_rtc_probe(struct platform_device *pdev) 396 { 397 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 398 struct m48t59_private *m48t59 = NULL; 399 struct resource *res; 400 int ret = -ENOMEM; 401 char *name; 402 const struct rtc_class_ops *ops; 403 404 /* This chip could be memory-mapped or I/O-mapped */ 405 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 406 if (!res) { 407 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 408 if (!res) 409 return -EINVAL; 410 } 411 412 if (res->flags & IORESOURCE_IO) { 413 /* If we are I/O-mapped, the platform should provide 414 * the operations accessing chip registers. 415 */ 416 if (!pdata || !pdata->write_byte || !pdata->read_byte) 417 return -EINVAL; 418 } else if (res->flags & IORESOURCE_MEM) { 419 /* we are memory-mapped */ 420 if (!pdata) { 421 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 422 if (!pdata) 423 return -ENOMEM; 424 /* Ensure we only kmalloc platform data once */ 425 pdev->dev.platform_data = pdata; 426 } 427 if (!pdata->type) 428 pdata->type = M48T59RTC_TYPE_M48T59; 429 430 /* Try to use the generic memory read/write ops */ 431 if (!pdata->write_byte) 432 pdata->write_byte = m48t59_mem_writeb; 433 if (!pdata->read_byte) 434 pdata->read_byte = m48t59_mem_readb; 435 } 436 437 m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL); 438 if (!m48t59) 439 return -ENOMEM; 440 441 m48t59->ioaddr = pdata->ioaddr; 442 443 if (!m48t59->ioaddr) { 444 /* ioaddr not mapped externally */ 445 m48t59->ioaddr = ioremap(res->start, res->end - res->start + 1); 446 if (!m48t59->ioaddr) 447 goto out; 448 } 449 450 /* Try to get irq number. We also can work in 451 * the mode without IRQ. 452 */ 453 m48t59->irq = platform_get_irq(pdev, 0); 454 if (m48t59->irq <= 0) 455 m48t59->irq = NO_IRQ; 456 457 if (m48t59->irq != NO_IRQ) { 458 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt, 459 IRQF_SHARED, "rtc-m48t59", &pdev->dev); 460 if (ret) 461 goto out; 462 } 463 switch (pdata->type) { 464 case M48T59RTC_TYPE_M48T59: 465 name = "m48t59"; 466 ops = &m48t59_rtc_ops; 467 pdata->offset = 0x1ff0; 468 break; 469 case M48T59RTC_TYPE_M48T02: 470 name = "m48t02"; 471 ops = &m48t02_rtc_ops; 472 pdata->offset = 0x7f0; 473 break; 474 case M48T59RTC_TYPE_M48T08: 475 name = "m48t08"; 476 ops = &m48t02_rtc_ops; 477 pdata->offset = 0x1ff0; 478 break; 479 default: 480 dev_err(&pdev->dev, "Unknown RTC type\n"); 481 ret = -ENODEV; 482 goto out; 483 } 484 485 spin_lock_init(&m48t59->lock); 486 platform_set_drvdata(pdev, m48t59); 487 488 m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE); 489 if (IS_ERR(m48t59->rtc)) { 490 ret = PTR_ERR(m48t59->rtc); 491 goto out; 492 } 493 494 m48t59_nvram_attr.size = pdata->offset; 495 496 ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 497 if (ret) { 498 rtc_device_unregister(m48t59->rtc); 499 goto out; 500 } 501 502 return 0; 503 504 out: 505 if (m48t59->irq != NO_IRQ) 506 free_irq(m48t59->irq, &pdev->dev); 507 if (m48t59->ioaddr) 508 iounmap(m48t59->ioaddr); 509 kfree(m48t59); 510 return ret; 511 } 512 513 static int __devexit m48t59_rtc_remove(struct platform_device *pdev) 514 { 515 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 516 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 517 518 sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 519 if (!IS_ERR(m48t59->rtc)) 520 rtc_device_unregister(m48t59->rtc); 521 if (m48t59->ioaddr && !pdata->ioaddr) 522 iounmap(m48t59->ioaddr); 523 if (m48t59->irq != NO_IRQ) 524 free_irq(m48t59->irq, &pdev->dev); 525 platform_set_drvdata(pdev, NULL); 526 kfree(m48t59); 527 return 0; 528 } 529 530 /* work with hotplug and coldplug */ 531 MODULE_ALIAS("platform:rtc-m48t59"); 532 533 static struct platform_driver m48t59_rtc_driver = { 534 .driver = { 535 .name = "rtc-m48t59", 536 .owner = THIS_MODULE, 537 }, 538 .probe = m48t59_rtc_probe, 539 .remove = __devexit_p(m48t59_rtc_remove), 540 }; 541 542 static int __init m48t59_rtc_init(void) 543 { 544 return platform_driver_register(&m48t59_rtc_driver); 545 } 546 547 static void __exit m48t59_rtc_exit(void) 548 { 549 platform_driver_unregister(&m48t59_rtc_driver); 550 } 551 552 module_init(m48t59_rtc_init); 553 module_exit(m48t59_rtc_exit); 554 555 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>"); 556 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver"); 557 MODULE_LICENSE("GPL"); 558