Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/rtc/rtc-m48t59.c

  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                 .owner  = THIS_MODULE,
508         },
509         .probe          = m48t59_rtc_probe,
510         .remove         = m48t59_rtc_remove,
511 };
512 
513 module_platform_driver(m48t59_rtc_driver);
514 
515 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
516 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
517 MODULE_LICENSE("GPL");
518 

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