| 1 | /* |
| 2 | * DS1286 Real Time Clock interface for Linux |
| 3 | * |
| 4 | * Copyright (C) 1998, 1999, 2000 Ralf Baechle |
| 5 | * Copyright (C) 2008 Thomas Bogendoerfer |
| 6 | * |
| 7 | * Based on code written by Paul Gortmaker. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify it |
| 10 | * under the terms of the GNU General Public License as published by the |
| 11 | * Free Software Foundation; either version 2 of the License, or (at your |
| 12 | * option) any later version. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/rtc.h> |
| 17 | #include <linux/platform_device.h> |
| 18 | #include <linux/bcd.h> |
| 19 | #include <linux/ds1286.h> |
| 20 | #include <linux/io.h> |
| 21 | #include <linux/slab.h> |
| 22 | |
| 23 | #define DRV_VERSION "1.0" |
| 24 | |
| 25 | struct ds1286_priv { |
| 26 | struct rtc_device *rtc; |
| 27 | u32 __iomem *rtcregs; |
| 28 | size_t size; |
| 29 | unsigned long baseaddr; |
| 30 | spinlock_t lock; |
| 31 | }; |
| 32 | |
| 33 | static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg) |
| 34 | { |
| 35 | return __raw_readl(&priv->rtcregs[reg]) & 0xff; |
| 36 | } |
| 37 | |
| 38 | static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg) |
| 39 | { |
| 40 | __raw_writel(data, &priv->rtcregs[reg]); |
| 41 | } |
| 42 | |
| 43 | #ifdef CONFIG_RTC_INTF_DEV |
| 44 | |
| 45 | static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) |
| 46 | { |
| 47 | struct ds1286_priv *priv = dev_get_drvdata(dev); |
| 48 | unsigned long flags; |
| 49 | unsigned char val; |
| 50 | |
| 51 | switch (cmd) { |
| 52 | case RTC_AIE_OFF: |
| 53 | /* Mask alarm int. enab. bit */ |
| 54 | spin_lock_irqsave(&priv->lock, flags); |
| 55 | val = ds1286_rtc_read(priv, RTC_CMD); |
| 56 | val |= RTC_TDM; |
| 57 | ds1286_rtc_write(priv, val, RTC_CMD); |
| 58 | spin_unlock_irqrestore(&priv->lock, flags); |
| 59 | break; |
| 60 | case RTC_AIE_ON: |
| 61 | /* Allow alarm interrupts. */ |
| 62 | spin_lock_irqsave(&priv->lock, flags); |
| 63 | val = ds1286_rtc_read(priv, RTC_CMD); |
| 64 | val &= ~RTC_TDM; |
| 65 | ds1286_rtc_write(priv, val, RTC_CMD); |
| 66 | spin_unlock_irqrestore(&priv->lock, flags); |
| 67 | break; |
| 68 | case RTC_WIE_OFF: |
| 69 | /* Mask watchdog int. enab. bit */ |
| 70 | spin_lock_irqsave(&priv->lock, flags); |
| 71 | val = ds1286_rtc_read(priv, RTC_CMD); |
| 72 | val |= RTC_WAM; |
| 73 | ds1286_rtc_write(priv, val, RTC_CMD); |
| 74 | spin_unlock_irqrestore(&priv->lock, flags); |
| 75 | break; |
| 76 | case RTC_WIE_ON: |
| 77 | /* Allow watchdog interrupts. */ |
| 78 | spin_lock_irqsave(&priv->lock, flags); |
| 79 | val = ds1286_rtc_read(priv, RTC_CMD); |
| 80 | val &= ~RTC_WAM; |
| 81 | ds1286_rtc_write(priv, val, RTC_CMD); |
| 82 | spin_unlock_irqrestore(&priv->lock, flags); |
| 83 | break; |
| 84 | default: |
| 85 | return -ENOIOCTLCMD; |
| 86 | } |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | #else |
| 91 | #define ds1286_ioctl NULL |
| 92 | #endif |
| 93 | |
| 94 | #ifdef CONFIG_PROC_FS |
| 95 | |
| 96 | static int ds1286_proc(struct device *dev, struct seq_file *seq) |
| 97 | { |
| 98 | struct ds1286_priv *priv = dev_get_drvdata(dev); |
| 99 | unsigned char month, cmd, amode; |
| 100 | const char *s; |
| 101 | |
| 102 | month = ds1286_rtc_read(priv, RTC_MONTH); |
| 103 | seq_printf(seq, |
| 104 | "oscillator\t: %s\n" |
| 105 | "square_wave\t: %s\n", |
| 106 | (month & RTC_EOSC) ? "disabled" : "enabled", |
| 107 | (month & RTC_ESQW) ? "disabled" : "enabled"); |
| 108 | |
| 109 | amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) | |
| 110 | ((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) | |
| 111 | ((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7); |
| 112 | switch (amode) { |
| 113 | case 7: |
| 114 | s = "each minute"; |
| 115 | break; |
| 116 | case 3: |
| 117 | s = "minutes match"; |
| 118 | break; |
| 119 | case 1: |
| 120 | s = "hours and minutes match"; |
| 121 | break; |
| 122 | case 0: |
| 123 | s = "days, hours and minutes match"; |
| 124 | break; |
| 125 | default: |
| 126 | s = "invalid"; |
| 127 | break; |
| 128 | } |
| 129 | seq_printf(seq, "alarm_mode\t: %s\n", s); |
| 130 | |
| 131 | cmd = ds1286_rtc_read(priv, RTC_CMD); |
| 132 | seq_printf(seq, |
| 133 | "alarm_enable\t: %s\n" |
| 134 | "wdog_alarm\t: %s\n" |
| 135 | "alarm_mask\t: %s\n" |
| 136 | "wdog_alarm_mask\t: %s\n" |
| 137 | "interrupt_mode\t: %s\n" |
| 138 | "INTB_mode\t: %s_active\n" |
| 139 | "interrupt_pins\t: %s\n", |
| 140 | (cmd & RTC_TDF) ? "yes" : "no", |
| 141 | (cmd & RTC_WAF) ? "yes" : "no", |
| 142 | (cmd & RTC_TDM) ? "disabled" : "enabled", |
| 143 | (cmd & RTC_WAM) ? "disabled" : "enabled", |
| 144 | (cmd & RTC_PU_LVL) ? "pulse" : "level", |
| 145 | (cmd & RTC_IBH_LO) ? "low" : "high", |
| 146 | (cmd & RTC_IPSW) ? "unswapped" : "swapped"); |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | #else |
| 151 | #define ds1286_proc NULL |
| 152 | #endif |
| 153 | |
| 154 | static int ds1286_read_time(struct device *dev, struct rtc_time *tm) |
| 155 | { |
| 156 | struct ds1286_priv *priv = dev_get_drvdata(dev); |
| 157 | unsigned char save_control; |
| 158 | unsigned long flags; |
| 159 | unsigned long uip_watchdog = jiffies; |
| 160 | |
| 161 | /* |
| 162 | * read RTC once any update in progress is done. The update |
| 163 | * can take just over 2ms. We wait 10 to 20ms. There is no need to |
| 164 | * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. |
| 165 | * If you need to know *exactly* when a second has started, enable |
| 166 | * periodic update complete interrupts, (via ioctl) and then |
| 167 | * immediately read /dev/rtc which will block until you get the IRQ. |
| 168 | * Once the read clears, read the RTC time (again via ioctl). Easy. |
| 169 | */ |
| 170 | |
| 171 | if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE) |
| 172 | while (time_before(jiffies, uip_watchdog + 2*HZ/100)) |
| 173 | barrier(); |
| 174 | |
| 175 | /* |
| 176 | * Only the values that we read from the RTC are set. We leave |
| 177 | * tm_wday, tm_yday and tm_isdst untouched. Even though the |
| 178 | * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated |
| 179 | * by the RTC when initially set to a non-zero value. |
| 180 | */ |
| 181 | spin_lock_irqsave(&priv->lock, flags); |
| 182 | save_control = ds1286_rtc_read(priv, RTC_CMD); |
| 183 | ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD); |
| 184 | |
| 185 | tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS); |
| 186 | tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES); |
| 187 | tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f; |
| 188 | tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE); |
| 189 | tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f; |
| 190 | tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR); |
| 191 | |
| 192 | ds1286_rtc_write(priv, save_control, RTC_CMD); |
| 193 | spin_unlock_irqrestore(&priv->lock, flags); |
| 194 | |
| 195 | tm->tm_sec = bcd2bin(tm->tm_sec); |
| 196 | tm->tm_min = bcd2bin(tm->tm_min); |
| 197 | tm->tm_hour = bcd2bin(tm->tm_hour); |
| 198 | tm->tm_mday = bcd2bin(tm->tm_mday); |
| 199 | tm->tm_mon = bcd2bin(tm->tm_mon); |
| 200 | tm->tm_year = bcd2bin(tm->tm_year); |
| 201 | |
| 202 | /* |
| 203 | * Account for differences between how the RTC uses the values |
| 204 | * and how they are defined in a struct rtc_time; |
| 205 | */ |
| 206 | if (tm->tm_year < 45) |
| 207 | tm->tm_year += 30; |
| 208 | tm->tm_year += 40; |
| 209 | if (tm->tm_year < 70) |
| 210 | tm->tm_year += 100; |
| 211 | |
| 212 | tm->tm_mon--; |
| 213 | |
| 214 | return rtc_valid_tm(tm); |
| 215 | } |
| 216 | |
| 217 | static int ds1286_set_time(struct device *dev, struct rtc_time *tm) |
| 218 | { |
| 219 | struct ds1286_priv *priv = dev_get_drvdata(dev); |
| 220 | unsigned char mon, day, hrs, min, sec; |
| 221 | unsigned char save_control; |
| 222 | unsigned int yrs; |
| 223 | unsigned long flags; |
| 224 | |
| 225 | yrs = tm->tm_year + 1900; |
| 226 | mon = tm->tm_mon + 1; /* tm_mon starts at zero */ |
| 227 | day = tm->tm_mday; |
| 228 | hrs = tm->tm_hour; |
| 229 | min = tm->tm_min; |
| 230 | sec = tm->tm_sec; |
| 231 | |
| 232 | if (yrs < 1970) |
| 233 | return -EINVAL; |
| 234 | |
| 235 | yrs -= 1940; |
| 236 | if (yrs > 255) /* They are unsigned */ |
| 237 | return -EINVAL; |
| 238 | |
| 239 | if (yrs >= 100) |
| 240 | yrs -= 100; |
| 241 | |
| 242 | sec = bin2bcd(sec); |
| 243 | min = bin2bcd(min); |
| 244 | hrs = bin2bcd(hrs); |
| 245 | day = bin2bcd(day); |
| 246 | mon = bin2bcd(mon); |
| 247 | yrs = bin2bcd(yrs); |
| 248 | |
| 249 | spin_lock_irqsave(&priv->lock, flags); |
| 250 | save_control = ds1286_rtc_read(priv, RTC_CMD); |
| 251 | ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD); |
| 252 | |
| 253 | ds1286_rtc_write(priv, yrs, RTC_YEAR); |
| 254 | ds1286_rtc_write(priv, mon, RTC_MONTH); |
| 255 | ds1286_rtc_write(priv, day, RTC_DATE); |
| 256 | ds1286_rtc_write(priv, hrs, RTC_HOURS); |
| 257 | ds1286_rtc_write(priv, min, RTC_MINUTES); |
| 258 | ds1286_rtc_write(priv, sec, RTC_SECONDS); |
| 259 | ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND); |
| 260 | |
| 261 | ds1286_rtc_write(priv, save_control, RTC_CMD); |
| 262 | spin_unlock_irqrestore(&priv->lock, flags); |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| 267 | { |
| 268 | struct ds1286_priv *priv = dev_get_drvdata(dev); |
| 269 | unsigned char cmd; |
| 270 | unsigned long flags; |
| 271 | |
| 272 | /* |
| 273 | * Only the values that we read from the RTC are set. That |
| 274 | * means only tm_wday, tm_hour, tm_min. |
| 275 | */ |
| 276 | spin_lock_irqsave(&priv->lock, flags); |
| 277 | alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f; |
| 278 | alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x1f; |
| 279 | alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x07; |
| 280 | cmd = ds1286_rtc_read(priv, RTC_CMD); |
| 281 | spin_unlock_irqrestore(&priv->lock, flags); |
| 282 | |
| 283 | alm->time.tm_min = bcd2bin(alm->time.tm_min); |
| 284 | alm->time.tm_hour = bcd2bin(alm->time.tm_hour); |
| 285 | alm->time.tm_sec = 0; |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| 290 | { |
| 291 | struct ds1286_priv *priv = dev_get_drvdata(dev); |
| 292 | unsigned char hrs, min, sec; |
| 293 | |
| 294 | hrs = alm->time.tm_hour; |
| 295 | min = alm->time.tm_min; |
| 296 | sec = alm->time.tm_sec; |
| 297 | |
| 298 | if (hrs >= 24) |
| 299 | hrs = 0xff; |
| 300 | |
| 301 | if (min >= 60) |
| 302 | min = 0xff; |
| 303 | |
| 304 | if (sec != 0) |
| 305 | return -EINVAL; |
| 306 | |
| 307 | min = bin2bcd(min); |
| 308 | hrs = bin2bcd(hrs); |
| 309 | |
| 310 | spin_lock(&priv->lock); |
| 311 | ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM); |
| 312 | ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM); |
| 313 | spin_unlock(&priv->lock); |
| 314 | |
| 315 | return 0; |
| 316 | } |
| 317 | |
| 318 | static const struct rtc_class_ops ds1286_ops = { |
| 319 | .ioctl = ds1286_ioctl, |
| 320 | .proc = ds1286_proc, |
| 321 | .read_time = ds1286_read_time, |
| 322 | .set_time = ds1286_set_time, |
| 323 | .read_alarm = ds1286_read_alarm, |
| 324 | .set_alarm = ds1286_set_alarm, |
| 325 | }; |
| 326 | |
| 327 | static int __devinit ds1286_probe(struct platform_device *pdev) |
| 328 | { |
| 329 | struct rtc_device *rtc; |
| 330 | struct resource *res; |
| 331 | struct ds1286_priv *priv; |
| 332 | int ret = 0; |
| 333 | |
| 334 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 335 | if (!res) |
| 336 | return -ENODEV; |
| 337 | priv = kzalloc(sizeof(struct ds1286_priv), GFP_KERNEL); |
| 338 | if (!priv) |
| 339 | return -ENOMEM; |
| 340 | |
| 341 | priv->size = res->end - res->start + 1; |
| 342 | if (!request_mem_region(res->start, priv->size, pdev->name)) { |
| 343 | ret = -EBUSY; |
| 344 | goto out; |
| 345 | } |
| 346 | priv->baseaddr = res->start; |
| 347 | priv->rtcregs = ioremap(priv->baseaddr, priv->size); |
| 348 | if (!priv->rtcregs) { |
| 349 | ret = -ENOMEM; |
| 350 | goto out; |
| 351 | } |
| 352 | spin_lock_init(&priv->lock); |
| 353 | rtc = rtc_device_register("ds1286", &pdev->dev, |
| 354 | &ds1286_ops, THIS_MODULE); |
| 355 | if (IS_ERR(rtc)) { |
| 356 | ret = PTR_ERR(rtc); |
| 357 | goto out; |
| 358 | } |
| 359 | priv->rtc = rtc; |
| 360 | platform_set_drvdata(pdev, priv); |
| 361 | return 0; |
| 362 | |
| 363 | out: |
| 364 | if (priv->rtc) |
| 365 | rtc_device_unregister(priv->rtc); |
| 366 | if (priv->rtcregs) |
| 367 | iounmap(priv->rtcregs); |
| 368 | if (priv->baseaddr) |
| 369 | release_mem_region(priv->baseaddr, priv->size); |
| 370 | kfree(priv); |
| 371 | return ret; |
| 372 | } |
| 373 | |
| 374 | static int __devexit ds1286_remove(struct platform_device *pdev) |
| 375 | { |
| 376 | struct ds1286_priv *priv = platform_get_drvdata(pdev); |
| 377 | |
| 378 | rtc_device_unregister(priv->rtc); |
| 379 | iounmap(priv->rtcregs); |
| 380 | release_mem_region(priv->baseaddr, priv->size); |
| 381 | kfree(priv); |
| 382 | return 0; |
| 383 | } |
| 384 | |
| 385 | static struct platform_driver ds1286_platform_driver = { |
| 386 | .driver = { |
| 387 | .name = "rtc-ds1286", |
| 388 | .owner = THIS_MODULE, |
| 389 | }, |
| 390 | .probe = ds1286_probe, |
| 391 | .remove = __devexit_p(ds1286_remove), |
| 392 | }; |
| 393 | |
| 394 | static int __init ds1286_init(void) |
| 395 | { |
| 396 | return platform_driver_register(&ds1286_platform_driver); |
| 397 | } |
| 398 | |
| 399 | static void __exit ds1286_exit(void) |
| 400 | { |
| 401 | platform_driver_unregister(&ds1286_platform_driver); |
| 402 | } |
| 403 | |
| 404 | MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>"); |
| 405 | MODULE_DESCRIPTION("DS1286 RTC driver"); |
| 406 | MODULE_LICENSE("GPL"); |
| 407 | MODULE_VERSION(DRV_VERSION); |
| 408 | MODULE_ALIAS("platform:rtc-ds1286"); |
| 409 | |
| 410 | module_init(ds1286_init); |
| 411 | module_exit(ds1286_exit); |