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 = dev_get_platdata(&pdev->dev); 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 = dev_get_platdata(&pdev->dev); 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 = dev_get_platdata(&pdev->dev); 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 = dev_get_platdata(&pdev->dev); 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_alarm_irq_enable(struct device *dev, unsigned int enabled) 267 { 268 struct platform_device *pdev = to_platform_device(dev); 269 struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); 270 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 271 unsigned long flags; 272 273 spin_lock_irqsave(&m48t59->lock, flags); 274 if (enabled) 275 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR); 276 else 277 M48T59_WRITE(0x00, M48T59_INTR); 278 spin_unlock_irqrestore(&m48t59->lock, flags); 279 280 return 0; 281 } 282 283 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq) 284 { 285 struct platform_device *pdev = to_platform_device(dev); 286 struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); 287 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 288 unsigned long flags; 289 u8 val; 290 291 spin_lock_irqsave(&m48t59->lock, flags); 292 val = M48T59_READ(M48T59_FLAGS); 293 spin_unlock_irqrestore(&m48t59->lock, flags); 294 295 seq_printf(seq, "battery\t\t: %s\n", 296 (val & M48T59_FLAGS_BF) ? "low" : "normal"); 297 return 0; 298 } 299 300 /* 301 * IRQ handler for the RTC 302 */ 303 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id) 304 { 305 struct device *dev = (struct device *)dev_id; 306 struct platform_device *pdev = to_platform_device(dev); 307 struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); 308 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 309 u8 event; 310 311 spin_lock(&m48t59->lock); 312 event = M48T59_READ(M48T59_FLAGS); 313 spin_unlock(&m48t59->lock); 314 315 if (event & M48T59_FLAGS_AF) { 316 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF)); 317 return IRQ_HANDLED; 318 } 319 320 return IRQ_NONE; 321 } 322 323 static const struct rtc_class_ops m48t59_rtc_ops = { 324 .read_time = m48t59_rtc_read_time, 325 .set_time = m48t59_rtc_set_time, 326 .read_alarm = m48t59_rtc_readalarm, 327 .set_alarm = m48t59_rtc_setalarm, 328 .proc = m48t59_rtc_proc, 329 .alarm_irq_enable = m48t59_rtc_alarm_irq_enable, 330 }; 331 332 static const struct rtc_class_ops m48t02_rtc_ops = { 333 .read_time = m48t59_rtc_read_time, 334 .set_time = m48t59_rtc_set_time, 335 }; 336 337 static ssize_t m48t59_nvram_read(struct file *filp, struct kobject *kobj, 338 struct bin_attribute *bin_attr, 339 char *buf, loff_t pos, size_t size) 340 { 341 struct device *dev = container_of(kobj, struct device, kobj); 342 struct platform_device *pdev = to_platform_device(dev); 343 struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); 344 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 345 ssize_t cnt = 0; 346 unsigned long flags; 347 348 for (; size > 0 && pos < pdata->offset; cnt++, size--) { 349 spin_lock_irqsave(&m48t59->lock, flags); 350 *buf++ = M48T59_READ(cnt); 351 spin_unlock_irqrestore(&m48t59->lock, flags); 352 } 353 354 return cnt; 355 } 356 357 static ssize_t m48t59_nvram_write(struct file *filp, struct kobject *kobj, 358 struct bin_attribute *bin_attr, 359 char *buf, loff_t pos, size_t size) 360 { 361 struct device *dev = container_of(kobj, struct device, kobj); 362 struct platform_device *pdev = to_platform_device(dev); 363 struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); 364 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 365 ssize_t cnt = 0; 366 unsigned long flags; 367 368 for (; size > 0 && pos < pdata->offset; cnt++, size--) { 369 spin_lock_irqsave(&m48t59->lock, flags); 370 M48T59_WRITE(*buf++, cnt); 371 spin_unlock_irqrestore(&m48t59->lock, flags); 372 } 373 374 return cnt; 375 } 376 377 static struct bin_attribute m48t59_nvram_attr = { 378 .attr = { 379 .name = "nvram", 380 .mode = S_IRUGO | S_IWUSR, 381 }, 382 .read = m48t59_nvram_read, 383 .write = m48t59_nvram_write, 384 }; 385 386 static int m48t59_rtc_probe(struct platform_device *pdev) 387 { 388 struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); 389 struct m48t59_private *m48t59 = NULL; 390 struct resource *res; 391 int ret = -ENOMEM; 392 char *name; 393 const struct rtc_class_ops *ops; 394 395 /* This chip could be memory-mapped or I/O-mapped */ 396 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 397 if (!res) { 398 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 399 if (!res) 400 return -EINVAL; 401 } 402 403 if (res->flags & IORESOURCE_IO) { 404 /* If we are I/O-mapped, the platform should provide 405 * the operations accessing chip registers. 406 */ 407 if (!pdata || !pdata->write_byte || !pdata->read_byte) 408 return -EINVAL; 409 } else if (res->flags & IORESOURCE_MEM) { 410 /* we are memory-mapped */ 411 if (!pdata) { 412 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), 413 GFP_KERNEL); 414 if (!pdata) 415 return -ENOMEM; 416 /* Ensure we only kmalloc platform data once */ 417 pdev->dev.platform_data = pdata; 418 } 419 if (!pdata->type) 420 pdata->type = M48T59RTC_TYPE_M48T59; 421 422 /* Try to use the generic memory read/write ops */ 423 if (!pdata->write_byte) 424 pdata->write_byte = m48t59_mem_writeb; 425 if (!pdata->read_byte) 426 pdata->read_byte = m48t59_mem_readb; 427 } 428 429 m48t59 = devm_kzalloc(&pdev->dev, sizeof(*m48t59), GFP_KERNEL); 430 if (!m48t59) 431 return -ENOMEM; 432 433 m48t59->ioaddr = pdata->ioaddr; 434 435 if (!m48t59->ioaddr) { 436 /* ioaddr not mapped externally */ 437 m48t59->ioaddr = devm_ioremap(&pdev->dev, res->start, 438 resource_size(res)); 439 if (!m48t59->ioaddr) 440 return ret; 441 } 442 443 /* Try to get irq number. We also can work in 444 * the mode without IRQ. 445 */ 446 m48t59->irq = platform_get_irq(pdev, 0); 447 if (m48t59->irq <= 0) 448 m48t59->irq = NO_IRQ; 449 450 if (m48t59->irq != NO_IRQ) { 451 ret = devm_request_irq(&pdev->dev, m48t59->irq, 452 m48t59_rtc_interrupt, IRQF_SHARED, 453 "rtc-m48t59", &pdev->dev); 454 if (ret) 455 return ret; 456 } 457 switch (pdata->type) { 458 case M48T59RTC_TYPE_M48T59: 459 name = "m48t59"; 460 ops = &m48t59_rtc_ops; 461 pdata->offset = 0x1ff0; 462 break; 463 case M48T59RTC_TYPE_M48T02: 464 name = "m48t02"; 465 ops = &m48t02_rtc_ops; 466 pdata->offset = 0x7f0; 467 break; 468 case M48T59RTC_TYPE_M48T08: 469 name = "m48t08"; 470 ops = &m48t02_rtc_ops; 471 pdata->offset = 0x1ff0; 472 break; 473 default: 474 dev_err(&pdev->dev, "Unknown RTC type\n"); 475 return -ENODEV; 476 } 477 478 spin_lock_init(&m48t59->lock); 479 platform_set_drvdata(pdev, m48t59); 480 481 m48t59->rtc = devm_rtc_device_register(&pdev->dev, name, ops, 482 THIS_MODULE); 483 if (IS_ERR(m48t59->rtc)) 484 return PTR_ERR(m48t59->rtc); 485 486 m48t59_nvram_attr.size = pdata->offset; 487 488 ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 489 if (ret) 490 return ret; 491 492 return 0; 493 } 494 495 static int m48t59_rtc_remove(struct platform_device *pdev) 496 { 497 sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 498 return 0; 499 } 500 501 /* work with hotplug and coldplug */ 502 MODULE_ALIAS("platform:rtc-m48t59"); 503 504 static struct platform_driver m48t59_rtc_driver = { 505 .driver = { 506 .name = "rtc-m48t59", 507 }, 508 .probe = m48t59_rtc_probe, 509 .remove = m48t59_rtc_remove, 510 }; 511 512 module_platform_driver(m48t59_rtc_driver); 513 514 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>"); 515 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver"); 516 MODULE_LICENSE("GPL"); 517