4 * Copyright (c) 2007 Wind River Systems, Inc.
6 * Author: Mark Zhan <rongkai.zhan@windriver.com>
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.
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.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>
27 #define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg))
28 #define M48T59_WRITE(val, reg) \
29 (pdata->write_byte(dev, pdata->offset + reg, val))
31 #define M48T59_SET_BITS(mask, reg) \
32 M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg))
33 #define M48T59_CLEAR_BITS(mask, reg) \
34 M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg))
36 struct m48t59_private {
39 struct rtc_device *rtc;
40 spinlock_t lock; /* serialize the NVRAM and RTC access */
44 * This is the generic access method when the chip is memory-mapped
47 m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val)
49 struct platform_device *pdev = to_platform_device(dev);
50 struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
52 writeb(val, m48t59->ioaddr+ofs);
56 m48t59_mem_readb(struct device *dev, u32 ofs)
58 struct platform_device *pdev = to_platform_device(dev);
59 struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
61 return readb(m48t59->ioaddr+ofs);
65 * NOTE: M48T59 only uses BCD mode
67 static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
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);
75 spin_lock_irqsave(&m48t59->lock, flags);
76 /* Issue the READ command */
77 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
79 tm->tm_year = BCD2BIN(M48T59_READ(M48T59_YEAR));
81 tm->tm_mon = BCD2BIN(M48T59_READ(M48T59_MONTH)) - 1;
82 tm->tm_mday = BCD2BIN(M48T59_READ(M48T59_MDAY));
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 */
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);
95 /* Clear the READ bit */
96 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
97 spin_unlock_irqrestore(&m48t59->lock, flags);
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);
105 static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
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);
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);
117 spin_lock_irqsave(&m48t59->lock, flags);
118 /* Issue the WRITE command */
119 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
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);
126 M48T59_WRITE((BIN2BCD(tm->tm_mon + 1) & 0x1F), M48T59_MONTH);
127 M48T59_WRITE(BIN2BCD(tm->tm_year % 100), M48T59_YEAR);
130 val = (M48T59_WDAY_CEB | M48T59_WDAY_CB);
131 val |= (BIN2BCD(tm->tm_wday) & 0x07);
132 M48T59_WRITE(val, M48T59_WDAY);
134 /* Clear the WRITE bit */
135 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
136 spin_unlock_irqrestore(&m48t59->lock, flags);
141 * Read alarm time and date in RTC
143 static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
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;
152 /* If no irq, we don't support ALARM */
153 if (m48t59->irq == NO_IRQ)
156 spin_lock_irqsave(&m48t59->lock, flags);
157 /* Issue the READ command */
158 M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
160 tm->tm_year = BCD2BIN(M48T59_READ(M48T59_YEAR));
162 tm->tm_mon = BCD2BIN(M48T59_READ(M48T59_MONTH)) - 1;
164 val = M48T59_READ(M48T59_WDAY);
165 if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB))
166 tm->tm_year += 100; /* one century */
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));
173 /* Clear the READ bit */
174 M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL);
175 spin_unlock_irqrestore(&m48t59->lock, flags);
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);
184 * Set alarm time and date in RTC
186 static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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;
195 /* If no irq, we don't support ALARM */
196 if (m48t59->irq == NO_IRQ)
200 * 0xff means "always match"
203 mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;
205 mday = M48T59_READ(M48T59_MDAY);
208 hour = (hour < 24) ? BIN2BCD(hour) : 0x00;
211 min = (min < 60) ? BIN2BCD(min) : 0x00;
214 sec = (sec < 60) ? BIN2BCD(sec) : 0x00;
216 spin_lock_irqsave(&m48t59->lock, flags);
217 /* Issue the WRITE command */
218 M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
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);
225 /* Clear the WRITE bit */
226 M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL);
227 spin_unlock_irqrestore(&m48t59->lock, flags);
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);
236 * Handle commands from user-space
238 static int m48t59_rtc_ioctl(struct device *dev, unsigned int cmd,
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);
247 spin_lock_irqsave(&m48t59->lock, flags);
249 case RTC_AIE_OFF: /* alarm interrupt off */
250 M48T59_WRITE(0x00, M48T59_INTR);
252 case RTC_AIE_ON: /* alarm interrupt on */
253 M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR);
259 spin_unlock_irqrestore(&m48t59->lock, flags);
264 static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq)
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);
272 spin_lock_irqsave(&m48t59->lock, flags);
273 val = M48T59_READ(M48T59_FLAGS);
274 spin_unlock_irqrestore(&m48t59->lock, flags);
276 seq_printf(seq, "battery\t\t: %s\n",
277 (val & M48T59_FLAGS_BF) ? "low" : "normal");
282 * IRQ handler for the RTC
284 static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id)
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);
292 spin_lock(&m48t59->lock);
293 event = M48T59_READ(M48T59_FLAGS);
294 spin_unlock(&m48t59->lock);
296 if (event & M48T59_FLAGS_AF) {
297 rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF));
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,
313 static const struct rtc_class_ops m48t02_rtc_ops = {
314 .read_time = m48t59_rtc_read_time,
315 .set_time = m48t59_rtc_set_time,
318 static ssize_t m48t59_nvram_read(struct kobject *kobj,
319 struct bin_attribute *bin_attr,
320 char *buf, loff_t pos, size_t size)
322 struct device *dev = container_of(kobj, struct device, kobj);
323 struct platform_device *pdev = to_platform_device(dev);
324 struct m48t59_plat_data *pdata = pdev->dev.platform_data;
325 struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
329 for (; size > 0 && pos < pdata->offset; cnt++, size--) {
330 spin_lock_irqsave(&m48t59->lock, flags);
331 *buf++ = M48T59_READ(cnt);
332 spin_unlock_irqrestore(&m48t59->lock, flags);
338 static ssize_t m48t59_nvram_write(struct kobject *kobj,
339 struct bin_attribute *bin_attr,
340 char *buf, loff_t pos, size_t size)
342 struct device *dev = container_of(kobj, struct device, kobj);
343 struct platform_device *pdev = to_platform_device(dev);
344 struct m48t59_plat_data *pdata = pdev->dev.platform_data;
345 struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
349 for (; size > 0 && pos < pdata->offset; cnt++, size--) {
350 spin_lock_irqsave(&m48t59->lock, flags);
351 M48T59_WRITE(*buf++, cnt);
352 spin_unlock_irqrestore(&m48t59->lock, flags);
358 static struct bin_attribute m48t59_nvram_attr = {
361 .mode = S_IRUGO | S_IWUSR,
362 .owner = THIS_MODULE,
364 .read = m48t59_nvram_read,
365 .write = m48t59_nvram_write,
368 static int __devinit m48t59_rtc_probe(struct platform_device *pdev)
370 struct m48t59_plat_data *pdata = pdev->dev.platform_data;
371 struct m48t59_private *m48t59 = NULL;
372 struct resource *res;
375 const struct rtc_class_ops *ops;
377 /* This chip could be memory-mapped or I/O-mapped */
378 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
380 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
385 if (res->flags & IORESOURCE_IO) {
386 /* If we are I/O-mapped, the platform should provide
387 * the operations accessing chip registers.
389 if (!pdata || !pdata->write_byte || !pdata->read_byte)
391 } else if (res->flags & IORESOURCE_MEM) {
392 /* we are memory-mapped */
394 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
397 /* Ensure we only kmalloc platform data once */
398 pdev->dev.platform_data = pdata;
401 pdata->type = M48T59RTC_TYPE_M48T59;
403 /* Try to use the generic memory read/write ops */
404 if (!pdata->write_byte)
405 pdata->write_byte = m48t59_mem_writeb;
406 if (!pdata->read_byte)
407 pdata->read_byte = m48t59_mem_readb;
410 m48t59 = kzalloc(sizeof(*m48t59), GFP_KERNEL);
414 m48t59->ioaddr = ioremap(res->start, res->end - res->start + 1);
418 /* Try to get irq number. We also can work in
419 * the mode without IRQ.
421 m48t59->irq = platform_get_irq(pdev, 0);
423 m48t59->irq = NO_IRQ;
425 if (m48t59->irq != NO_IRQ) {
426 ret = request_irq(m48t59->irq, m48t59_rtc_interrupt,
427 IRQF_SHARED, "rtc-m48t59", &pdev->dev);
431 switch (pdata->type) {
432 case M48T59RTC_TYPE_M48T59:
434 ops = &m48t59_rtc_ops;
435 pdata->offset = 0x1ff0;
437 case M48T59RTC_TYPE_M48T02:
439 ops = &m48t02_rtc_ops;
440 pdata->offset = 0x7f0;
442 case M48T59RTC_TYPE_M48T08:
444 ops = &m48t02_rtc_ops;
445 pdata->offset = 0x1ff0;
448 dev_err(&pdev->dev, "Unknown RTC type\n");
453 m48t59->rtc = rtc_device_register(name, &pdev->dev, ops, THIS_MODULE);
454 if (IS_ERR(m48t59->rtc)) {
455 ret = PTR_ERR(m48t59->rtc);
459 m48t59_nvram_attr.size = pdata->offset;
461 ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
465 spin_lock_init(&m48t59->lock);
466 platform_set_drvdata(pdev, m48t59);
470 if (!IS_ERR(m48t59->rtc))
471 rtc_device_unregister(m48t59->rtc);
472 if (m48t59->irq != NO_IRQ)
473 free_irq(m48t59->irq, &pdev->dev);
475 iounmap(m48t59->ioaddr);
481 static int __devexit m48t59_rtc_remove(struct platform_device *pdev)
483 struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
485 sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr);
486 if (!IS_ERR(m48t59->rtc))
487 rtc_device_unregister(m48t59->rtc);
489 iounmap(m48t59->ioaddr);
490 if (m48t59->irq != NO_IRQ)
491 free_irq(m48t59->irq, &pdev->dev);
492 platform_set_drvdata(pdev, NULL);
497 /* work with hotplug and coldplug */
498 MODULE_ALIAS("platform:rtc-m48t59");
500 static struct platform_driver m48t59_rtc_driver = {
502 .name = "rtc-m48t59",
503 .owner = THIS_MODULE,
505 .probe = m48t59_rtc_probe,
506 .remove = __devexit_p(m48t59_rtc_remove),
509 static int __init m48t59_rtc_init(void)
511 return platform_driver_register(&m48t59_rtc_driver);
514 static void __exit m48t59_rtc_exit(void)
516 platform_driver_unregister(&m48t59_rtc_driver);
519 module_init(m48t59_rtc_init);
520 module_exit(m48t59_rtc_exit);
522 MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>");
523 MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver");
524 MODULE_LICENSE("GPL");