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, reg) 28 #define M48T59_WRITE(val, reg) pdata->write_byte(dev, reg, val) 29 30 #define M48T59_SET_BITS(mask, reg) \ 31 M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg)) 32 #define M48T59_CLEAR_BITS(mask, reg) \ 33 M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg)) 34 35 struct m48t59_private { 36 void __iomem *ioaddr; 37 unsigned int size; /* iomem size */ 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 ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) { 86 dev_dbg(dev, "Century bit is enabled\n"); 87 tm->tm_year += 100; /* one century */ 88 } 89 90 tm->tm_wday = BCD2BIN(val & 0x07); 91 tm->tm_hour = BCD2BIN(M48T59_READ(M48T59_HOUR) & 0x3F); 92 tm->tm_min = BCD2BIN(M48T59_READ(M48T59_MIN) & 0x7F); 93 tm->tm_sec = BCD2BIN(M48T59_READ(M48T59_SEC) & 0x7F); 94 95 /* Clear the READ bit */ 96 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); 97 spin_unlock_irqrestore(&m48t59->lock, flags); 98 99 dev_dbg(dev, "RTC read time %04d-%02d-%02d %02d/%02d/%02d\n", 100 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 101 tm->tm_hour, tm->tm_min, tm->tm_sec); 102 return 0; 103 } 104 105 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm) 106 { 107 struct platform_device *pdev = to_platform_device(dev); 108 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 109 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 110 unsigned long flags; 111 u8 val = 0; 112 113 dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n", 114 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 115 tm->tm_hour, tm->tm_min, tm->tm_sec); 116 117 spin_lock_irqsave(&m48t59->lock, flags); 118 /* Issue the WRITE command */ 119 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 120 121 M48T59_WRITE((BIN2BCD(tm->tm_sec) & 0x7F), M48T59_SEC); 122 M48T59_WRITE((BIN2BCD(tm->tm_min) & 0x7F), M48T59_MIN); 123 M48T59_WRITE((BIN2BCD(tm->tm_hour) & 0x3F), M48T59_HOUR); 124 M48T59_WRITE((BIN2BCD(tm->tm_mday) & 0x3F), M48T59_MDAY); 125 /* tm_mon is 0-11 */ 126 M48T59_WRITE((BIN2BCD(tm->tm_mon + 1) & 0x1F), M48T59_MONTH); 127 M48T59_WRITE(BIN2BCD(tm->tm_year % 100), M48T59_YEAR); 128 129 if (tm->tm_year/100) 130 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB); 131 val |= (BIN2BCD(tm->tm_wday) & 0x07); 132 M48T59_WRITE(val, M48T59_WDAY); 133 134 /* Clear the WRITE bit */ 135 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 136 spin_unlock_irqrestore(&m48t59->lock, flags); 137 return 0; 138 } 139 140 /* 141 * Read alarm time and date in RTC 142 */ 143 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 144 { 145 struct platform_device *pdev = to_platform_device(dev); 146 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 147 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 148 struct rtc_time *tm = &alrm->time; 149 unsigned long flags; 150 u8 val; 151 152 /* If no irq, we don't support ALARM */ 153 if (m48t59->irq == NO_IRQ) 154 return -EIO; 155 156 spin_lock_irqsave(&m48t59->lock, flags); 157 /* Issue the READ command */ 158 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); 159 160 tm->tm_year = BCD2BIN(M48T59_READ(M48T59_YEAR)); 161 /* tm_mon is 0-11 */ 162 tm->tm_mon = BCD2BIN(M48T59_READ(M48T59_MONTH)) - 1; 163 164 val = M48T59_READ(M48T59_WDAY); 165 if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) 166 tm->tm_year += 100; /* one century */ 167 168 tm->tm_mday = BCD2BIN(M48T59_READ(M48T59_ALARM_DATE)); 169 tm->tm_hour = BCD2BIN(M48T59_READ(M48T59_ALARM_HOUR)); 170 tm->tm_min = BCD2BIN(M48T59_READ(M48T59_ALARM_MIN)); 171 tm->tm_sec = BCD2BIN(M48T59_READ(M48T59_ALARM_SEC)); 172 173 /* Clear the READ bit */ 174 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); 175 spin_unlock_irqrestore(&m48t59->lock, flags); 176 177 dev_dbg(dev, "RTC read alarm time %04d-%02d-%02d %02d/%02d/%02d\n", 178 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 179 tm->tm_hour, tm->tm_min, tm->tm_sec); 180 return 0; 181 } 182 183 /* 184 * Set alarm time and date in RTC 185 */ 186 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 187 { 188 struct platform_device *pdev = to_platform_device(dev); 189 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 190 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 191 struct rtc_time *tm = &alrm->time; 192 u8 mday, hour, min, sec; 193 unsigned long flags; 194 195 /* If no irq, we don't support ALARM */ 196 if (m48t59->irq == NO_IRQ) 197 return -EIO; 198 199 /* 200 * 0xff means "always match" 201 */ 202 mday = tm->tm_mday; 203 mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff; 204 if (mday == 0xff) 205 mday = M48T59_READ(M48T59_MDAY); 206 207 hour = tm->tm_hour; 208 hour = (hour < 24) ? BIN2BCD(hour) : 0x00; 209 210 min = tm->tm_min; 211 min = (min < 60) ? BIN2BCD(min) : 0x00; 212 213 sec = tm->tm_sec; 214 sec = (sec < 60) ? BIN2BCD(sec) : 0x00; 215 216 spin_lock_irqsave(&m48t59->lock, flags); 217 /* Issue the WRITE command */ 218 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 219 220 M48T59_WRITE(mday, M48T59_ALARM_DATE); 221 M48T59_WRITE(hour, M48T59_ALARM_HOUR); 222 M48T59_WRITE(min, M48T59_ALARM_MIN); 223 M48T59_WRITE(sec, M48T59_ALARM_SEC); 224 225 /* Clear the WRITE bit */ 226 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); 227 spin_unlock_irqrestore(&m48t59->lock, flags); 228 229 dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n", 230 tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, 231 tm->tm_hour, tm->tm_min, tm->tm_sec); 232 return 0; 233 } 234 235 /* 236 * Handle commands from user-space 237 */ 238 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd, 239 unsigned long arg) 240 { 241 struct platform_device *pdev = to_platform_device(dev); 242 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 243 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 244 unsigned long flags; 245 int ret = 0; 246 247 spin_lock_irqsave(&m48t59->lock, flags); 248 switch (cmd) { 249 case RTC_AIE_OFF: /* alarm interrupt off */ 250 M48T59_WRITE(0x00, M48T59_INTR); 251 break; 252 case RTC_AIE_ON: /* alarm interrupt on */ 253 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR); 254 break; 255 default: 256 ret = -ENOIOCTLCMD; 257 break; 258 } 259 spin_unlock_irqrestore(&m48t59->lock, flags); 260 261 return ret; 262 } 263 264 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq) 265 { 266 struct platform_device *pdev = to_platform_device(dev); 267 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 268 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 269 unsigned long flags; 270 u8 val; 271 272 spin_lock_irqsave(&m48t59->lock, flags); 273 val = M48T59_READ(M48T59_FLAGS); 274 spin_unlock_irqrestore(&m48t59->lock, flags); 275 276 seq_printf(seq, "battery\t\t: %s\n", 277 (val & M48T59_FLAGS_BF) ? "low" : "normal"); 278 return 0; 279 } 280 281 /* 282 * IRQ handler for the RTC 283 */ 284 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id) 285 { 286 struct device *dev = (struct device *)dev_id; 287 struct platform_device *pdev = to_platform_device(dev); 288 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 289 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 290 u8 event; 291 292 spin_lock(&m48t59->lock); 293 event = M48T59_READ(M48T59_FLAGS); 294 spin_unlock(&m48t59->lock); 295 296 if (event & M48T59_FLAGS_AF) { 297 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF)); 298 return IRQ_HANDLED; 299 } 300 301 return IRQ_NONE; 302 } 303 304 static const struct rtc_class_ops m48t59_rtc_ops = { 305 .ioctl = m48t59_rtc_ioctl, 306 .read_time = m48t59_rtc_read_time, 307 .set_time = m48t59_rtc_set_time, 308 .read_alarm = m48t59_rtc_readalarm, 309 .set_alarm = m48t59_rtc_setalarm, 310 .proc = m48t59_rtc_proc, 311 }; 312 313 static ssize_t m48t59_nvram_read(struct kobject *kobj, 314 struct bin_attribute *bin_attr, 315 char *buf, loff_t pos, size_t size) 316 { 317 struct device *dev = container_of(kobj, struct device, kobj); 318 struct platform_device *pdev = to_platform_device(dev); 319 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 320 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 321 ssize_t cnt = 0; 322 unsigned long flags; 323 324 for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) { 325 spin_lock_irqsave(&m48t59->lock, flags); 326 *buf++ = M48T59_READ(cnt); 327 spin_unlock_irqrestore(&m48t59->lock, flags); 328 } 329 330 return cnt; 331 } 332 333 static ssize_t m48t59_nvram_write(struct kobject *kobj, 334 struct bin_attribute *bin_attr, 335 char *buf, loff_t pos, size_t size) 336 { 337 struct device *dev = container_of(kobj, struct device, kobj); 338 struct platform_device *pdev = to_platform_device(dev); 339 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 340 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 341 ssize_t cnt = 0; 342 unsigned long flags; 343 344 for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) { 345 spin_lock_irqsave(&m48t59->lock, flags); 346 M48T59_WRITE(*buf++, cnt); 347 spin_unlock_irqrestore(&m48t59->lock, flags); 348 } 349 350 return cnt; 351 } 352 353 static struct bin_attribute m48t59_nvram_attr = { 354 .attr = { 355 .name = "nvram", 356 .mode = S_IRUGO | S_IWUGO, 357 .owner = THIS_MODULE, 358 }, 359 .read = m48t59_nvram_read, 360 .write = m48t59_nvram_write, 361 }; 362 363 static int __devinit m48t59_rtc_probe(struct platform_device *pdev) 364 { 365 struct m48t59_plat_data *pdata = pdev->dev.platform_data; 366 struct m48t59_private *m48t59 = NULL; 367 struct resource *res; 368 int ret = -ENOMEM; 369 370 /* This chip could be memory-mapped or I/O-mapped */ 371 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 372 if (!res) { 373 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 374 if (!res) 375 return -EINVAL; 376 } 377 378 if (res->flags & IORESOURCE_IO) { 379 /* If we are I/O-mapped, the platform should provide 380 * the operations accessing chip registers. 381 */ 382 if (!pdata || !pdata->write_byte || !pdata->read_byte) 383 return -EINVAL; 384 } else if (res->flags & IORESOURCE_MEM) { 385 /* we are memory-mapped */ 386 if (!pdata) { 387 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 388 if (!pdata) 389 return -ENOMEM; 390 /* Ensure we only kmalloc platform data once */ 391 pdev->dev.platform_data = pdata; 392 } 393 394 /* Try to use the generic memory read/write ops */ 395 if (!pdata->write_byte) 396 pdata->write_byte = m48t59_mem_writeb; 397 if (!pdata->read_byte) 398 pdata->read_byte = m48t59_mem_readb; 399 } 400 401 m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL); 402 if (!m48t59) 403 return -ENOMEM; 404 405 m48t59->size = res->end - res->start + 1; 406 m48t59->ioaddr = ioremap(res->start, m48t59->size); 407 if (!m48t59->ioaddr) 408 goto out; 409 410 /* Try to get irq number. We also can work in 411 * the mode without IRQ. 412 */ 413 m48t59->irq = platform_get_irq(pdev, 0); 414 if (m48t59->irq < 0) 415 m48t59->irq = NO_IRQ; 416 417 if (m48t59->irq != NO_IRQ) { 418 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt, 419 IRQF_SHARED, "rtc-m48t59", &pdev->dev); 420 if (ret) 421 goto out; 422 } 423 424 m48t59->rtc = rtc_device_register("m48t59", &pdev->dev, 425 &m48t59_rtc_ops, THIS_MODULE); 426 if (IS_ERR(m48t59->rtc)) { 427 ret = PTR_ERR(m48t59->rtc); 428 goto out; 429 } 430 431 ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 432 if (ret) 433 goto out; 434 435 spin_lock_init(&m48t59->lock); 436 platform_set_drvdata(pdev, m48t59); 437 return 0; 438 439 out: 440 if (!IS_ERR(m48t59->rtc)) 441 rtc_device_unregister(m48t59->rtc); 442 if (m48t59->irq != NO_IRQ) 443 free_irq(m48t59->irq, &pdev->dev); 444 if (m48t59->ioaddr) 445 iounmap(m48t59->ioaddr); 446 if (m48t59) 447 kfree(m48t59); 448 return ret; 449 } 450 451 static int __devexit m48t59_rtc_remove(struct platform_device *pdev) 452 { 453 struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 454 455 sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); 456 if (!IS_ERR(m48t59->rtc)) 457 rtc_device_unregister(m48t59->rtc); 458 if (m48t59->ioaddr) 459 iounmap(m48t59->ioaddr); 460 if (m48t59->irq != NO_IRQ) 461 free_irq(m48t59->irq, &pdev->dev); 462 platform_set_drvdata(pdev, NULL); 463 kfree(m48t59); 464 return 0; 465 } 466 467 static struct platform_driver m48t59_rtc_platdrv = { 468 .driver = { 469 .name = "rtc-m48t59", 470 .owner = THIS_MODULE, 471 }, 472 .probe = m48t59_rtc_probe, 473 .remove = __devexit_p(m48t59_rtc_remove), 474 }; 475 476 static int __init m48t59_rtc_init(void) 477 { 478 return platform_driver_register(&m48t59_rtc_platdrv); 479 } 480 481 static void __exit m48t59_rtc_exit(void) 482 { 483 platform_driver_unregister(&m48t59_rtc_platdrv); 484 } 485 486 module_init(m48t59_rtc_init); 487 module_exit(m48t59_rtc_exit); 488 489 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>"); 490 MODULE_DESCRIPTION("M48T59 RTC driver"); 491 MODULE_LICENSE("GPL"); 492