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