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 spinlock_t lock; 29 }; 30 31 static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg) 32 { 33 return __raw_readl(&priv->rtcregs[reg]) & 0xff; 34 } 35 36 static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg) 37 { 38 __raw_writel(data, &priv->rtcregs[reg]); 39 } 40 41 42 static int ds1286_alarm_irq_enable(struct device *dev, unsigned int enabled) 43 { 44 struct ds1286_priv *priv = dev_get_drvdata(dev); 45 unsigned long flags; 46 unsigned char val; 47 48 /* Allow or mask alarm interrupts */ 49 spin_lock_irqsave(&priv->lock, flags); 50 val = ds1286_rtc_read(priv, RTC_CMD); 51 if (enabled) 52 val &= ~RTC_TDM; 53 else 54 val |= RTC_TDM; 55 ds1286_rtc_write(priv, val, RTC_CMD); 56 spin_unlock_irqrestore(&priv->lock, flags); 57 58 return 0; 59 } 60 61 #ifdef CONFIG_RTC_INTF_DEV 62 63 static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 64 { 65 struct ds1286_priv *priv = dev_get_drvdata(dev); 66 unsigned long flags; 67 unsigned char val; 68 69 switch (cmd) { 70 case RTC_WIE_OFF: 71 /* Mask watchdog int. enab. bit */ 72 spin_lock_irqsave(&priv->lock, flags); 73 val = ds1286_rtc_read(priv, RTC_CMD); 74 val |= RTC_WAM; 75 ds1286_rtc_write(priv, val, RTC_CMD); 76 spin_unlock_irqrestore(&priv->lock, flags); 77 break; 78 case RTC_WIE_ON: 79 /* Allow watchdog interrupts. */ 80 spin_lock_irqsave(&priv->lock, flags); 81 val = ds1286_rtc_read(priv, RTC_CMD); 82 val &= ~RTC_WAM; 83 ds1286_rtc_write(priv, val, RTC_CMD); 84 spin_unlock_irqrestore(&priv->lock, flags); 85 break; 86 default: 87 return -ENOIOCTLCMD; 88 } 89 return 0; 90 } 91 92 #else 93 #define ds1286_ioctl NULL 94 #endif 95 96 #ifdef CONFIG_PROC_FS 97 98 static int ds1286_proc(struct device *dev, struct seq_file *seq) 99 { 100 struct ds1286_priv *priv = dev_get_drvdata(dev); 101 unsigned char month, cmd, amode; 102 const char *s; 103 104 month = ds1286_rtc_read(priv, RTC_MONTH); 105 seq_printf(seq, 106 "oscillator\t: %s\n" 107 "square_wave\t: %s\n", 108 (month & RTC_EOSC) ? "disabled" : "enabled", 109 (month & RTC_ESQW) ? "disabled" : "enabled"); 110 111 amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) | 112 ((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) | 113 ((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7); 114 switch (amode) { 115 case 7: 116 s = "each minute"; 117 break; 118 case 3: 119 s = "minutes match"; 120 break; 121 case 1: 122 s = "hours and minutes match"; 123 break; 124 case 0: 125 s = "days, hours and minutes match"; 126 break; 127 default: 128 s = "invalid"; 129 break; 130 } 131 seq_printf(seq, "alarm_mode\t: %s\n", s); 132 133 cmd = ds1286_rtc_read(priv, RTC_CMD); 134 seq_printf(seq, 135 "alarm_enable\t: %s\n" 136 "wdog_alarm\t: %s\n" 137 "alarm_mask\t: %s\n" 138 "wdog_alarm_mask\t: %s\n" 139 "interrupt_mode\t: %s\n" 140 "INTB_mode\t: %s_active\n" 141 "interrupt_pins\t: %s\n", 142 (cmd & RTC_TDF) ? "yes" : "no", 143 (cmd & RTC_WAF) ? "yes" : "no", 144 (cmd & RTC_TDM) ? "disabled" : "enabled", 145 (cmd & RTC_WAM) ? "disabled" : "enabled", 146 (cmd & RTC_PU_LVL) ? "pulse" : "level", 147 (cmd & RTC_IBH_LO) ? "low" : "high", 148 (cmd & RTC_IPSW) ? "unswapped" : "swapped"); 149 return 0; 150 } 151 152 #else 153 #define ds1286_proc NULL 154 #endif 155 156 static int ds1286_read_time(struct device *dev, struct rtc_time *tm) 157 { 158 struct ds1286_priv *priv = dev_get_drvdata(dev); 159 unsigned char save_control; 160 unsigned long flags; 161 unsigned long uip_watchdog = jiffies; 162 163 /* 164 * read RTC once any update in progress is done. The update 165 * can take just over 2ms. We wait 10 to 20ms. There is no need to 166 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. 167 * If you need to know *exactly* when a second has started, enable 168 * periodic update complete interrupts, (via ioctl) and then 169 * immediately read /dev/rtc which will block until you get the IRQ. 170 * Once the read clears, read the RTC time (again via ioctl). Easy. 171 */ 172 173 if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE) 174 while (time_before(jiffies, uip_watchdog + 2*HZ/100)) 175 barrier(); 176 177 /* 178 * Only the values that we read from the RTC are set. We leave 179 * tm_wday, tm_yday and tm_isdst untouched. Even though the 180 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated 181 * by the RTC when initially set to a non-zero value. 182 */ 183 spin_lock_irqsave(&priv->lock, flags); 184 save_control = ds1286_rtc_read(priv, RTC_CMD); 185 ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD); 186 187 tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS); 188 tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES); 189 tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f; 190 tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE); 191 tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f; 192 tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR); 193 194 ds1286_rtc_write(priv, save_control, RTC_CMD); 195 spin_unlock_irqrestore(&priv->lock, flags); 196 197 tm->tm_sec = bcd2bin(tm->tm_sec); 198 tm->tm_min = bcd2bin(tm->tm_min); 199 tm->tm_hour = bcd2bin(tm->tm_hour); 200 tm->tm_mday = bcd2bin(tm->tm_mday); 201 tm->tm_mon = bcd2bin(tm->tm_mon); 202 tm->tm_year = bcd2bin(tm->tm_year); 203 204 /* 205 * Account for differences between how the RTC uses the values 206 * and how they are defined in a struct rtc_time; 207 */ 208 if (tm->tm_year < 45) 209 tm->tm_year += 30; 210 tm->tm_year += 40; 211 if (tm->tm_year < 70) 212 tm->tm_year += 100; 213 214 tm->tm_mon--; 215 216 return rtc_valid_tm(tm); 217 } 218 219 static int ds1286_set_time(struct device *dev, struct rtc_time *tm) 220 { 221 struct ds1286_priv *priv = dev_get_drvdata(dev); 222 unsigned char mon, day, hrs, min, sec; 223 unsigned char save_control; 224 unsigned int yrs; 225 unsigned long flags; 226 227 yrs = tm->tm_year + 1900; 228 mon = tm->tm_mon + 1; /* tm_mon starts at zero */ 229 day = tm->tm_mday; 230 hrs = tm->tm_hour; 231 min = tm->tm_min; 232 sec = tm->tm_sec; 233 234 if (yrs < 1970) 235 return -EINVAL; 236 237 yrs -= 1940; 238 if (yrs > 255) /* They are unsigned */ 239 return -EINVAL; 240 241 if (yrs >= 100) 242 yrs -= 100; 243 244 sec = bin2bcd(sec); 245 min = bin2bcd(min); 246 hrs = bin2bcd(hrs); 247 day = bin2bcd(day); 248 mon = bin2bcd(mon); 249 yrs = bin2bcd(yrs); 250 251 spin_lock_irqsave(&priv->lock, flags); 252 save_control = ds1286_rtc_read(priv, RTC_CMD); 253 ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD); 254 255 ds1286_rtc_write(priv, yrs, RTC_YEAR); 256 ds1286_rtc_write(priv, mon, RTC_MONTH); 257 ds1286_rtc_write(priv, day, RTC_DATE); 258 ds1286_rtc_write(priv, hrs, RTC_HOURS); 259 ds1286_rtc_write(priv, min, RTC_MINUTES); 260 ds1286_rtc_write(priv, sec, RTC_SECONDS); 261 ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND); 262 263 ds1286_rtc_write(priv, save_control, RTC_CMD); 264 spin_unlock_irqrestore(&priv->lock, flags); 265 return 0; 266 } 267 268 static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 269 { 270 struct ds1286_priv *priv = dev_get_drvdata(dev); 271 unsigned long flags; 272 273 /* 274 * Only the values that we read from the RTC are set. That 275 * means only tm_wday, tm_hour, tm_min. 276 */ 277 spin_lock_irqsave(&priv->lock, flags); 278 alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f; 279 alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x1f; 280 alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x07; 281 ds1286_rtc_read(priv, RTC_CMD); 282 spin_unlock_irqrestore(&priv->lock, flags); 283 284 alm->time.tm_min = bcd2bin(alm->time.tm_min); 285 alm->time.tm_hour = bcd2bin(alm->time.tm_hour); 286 alm->time.tm_sec = 0; 287 return 0; 288 } 289 290 static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 291 { 292 struct ds1286_priv *priv = dev_get_drvdata(dev); 293 unsigned char hrs, min, sec; 294 295 hrs = alm->time.tm_hour; 296 min = alm->time.tm_min; 297 sec = alm->time.tm_sec; 298 299 if (hrs >= 24) 300 hrs = 0xff; 301 302 if (min >= 60) 303 min = 0xff; 304 305 if (sec != 0) 306 return -EINVAL; 307 308 min = bin2bcd(min); 309 hrs = bin2bcd(hrs); 310 311 spin_lock(&priv->lock); 312 ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM); 313 ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM); 314 spin_unlock(&priv->lock); 315 316 return 0; 317 } 318 319 static const struct rtc_class_ops ds1286_ops = { 320 .ioctl = ds1286_ioctl, 321 .proc = ds1286_proc, 322 .read_time = ds1286_read_time, 323 .set_time = ds1286_set_time, 324 .read_alarm = ds1286_read_alarm, 325 .set_alarm = ds1286_set_alarm, 326 .alarm_irq_enable = ds1286_alarm_irq_enable, 327 }; 328 329 static int ds1286_probe(struct platform_device *pdev) 330 { 331 struct rtc_device *rtc; 332 struct resource *res; 333 struct ds1286_priv *priv; 334 335 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 336 if (!res) 337 return -ENODEV; 338 priv = devm_kzalloc(&pdev->dev, sizeof(struct ds1286_priv), GFP_KERNEL); 339 if (!priv) 340 return -ENOMEM; 341 342 priv->rtcregs = devm_ioremap_resource(&pdev->dev, res); 343 if (IS_ERR(priv->rtcregs)) 344 return PTR_ERR(priv->rtcregs); 345 346 spin_lock_init(&priv->lock); 347 platform_set_drvdata(pdev, priv); 348 rtc = devm_rtc_device_register(&pdev->dev, "ds1286", &ds1286_ops, 349 THIS_MODULE); 350 if (IS_ERR(rtc)) 351 return PTR_ERR(rtc); 352 priv->rtc = rtc; 353 return 0; 354 } 355 356 static struct platform_driver ds1286_platform_driver = { 357 .driver = { 358 .name = "rtc-ds1286", 359 }, 360 .probe = ds1286_probe, 361 }; 362 363 module_platform_driver(ds1286_platform_driver); 364 365 MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>"); 366 MODULE_DESCRIPTION("DS1286 RTC driver"); 367 MODULE_LICENSE("GPL"); 368 MODULE_VERSION(DRV_VERSION); 369 MODULE_ALIAS("platform:rtc-ds1286"); 370