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11#include <linux/bcd.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/gfp.h>
15#include <linux/delay.h>
16#include <linux/jiffies.h>
17#include <linux/interrupt.h>
18#include <linux/rtc.h>
19#include <linux/platform_device.h>
20#include <linux/io.h>
21#include <linux/module.h>
22
23#define DRV_VERSION "0.3"
24
25#define RTC_REG_SIZE 0x2000
26#define RTC_OFFSET 0x1ff0
27
28#define RTC_FLAGS (RTC_OFFSET + 0)
29#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
30#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
31#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
32#define RTC_DATE_ALARM (RTC_OFFSET + 5)
33#define RTC_INTERRUPTS (RTC_OFFSET + 6)
34#define RTC_WATCHDOG (RTC_OFFSET + 7)
35#define RTC_CONTROL (RTC_OFFSET + 8)
36#define RTC_CENTURY (RTC_OFFSET + 8)
37#define RTC_SECONDS (RTC_OFFSET + 9)
38#define RTC_MINUTES (RTC_OFFSET + 10)
39#define RTC_HOURS (RTC_OFFSET + 11)
40#define RTC_DAY (RTC_OFFSET + 12)
41#define RTC_DATE (RTC_OFFSET + 13)
42#define RTC_MONTH (RTC_OFFSET + 14)
43#define RTC_YEAR (RTC_OFFSET + 15)
44
45#define RTC_CENTURY_MASK 0x3f
46#define RTC_SECONDS_MASK 0x7f
47#define RTC_DAY_MASK 0x07
48
49
50#define RTC_WRITE 0x80
51#define RTC_READ 0x40
52
53
54#define RTC_STOP 0x80
55
56
57#define RTC_FLAGS_AF 0x40
58#define RTC_FLAGS_BLF 0x10
59
60
61#define RTC_INTS_AE 0x80
62
63struct rtc_plat_data {
64 struct rtc_device *rtc;
65 void __iomem *ioaddr;
66 unsigned long last_jiffies;
67 int irq;
68 unsigned int irqen;
69 int alrm_sec;
70 int alrm_min;
71 int alrm_hour;
72 int alrm_mday;
73 spinlock_t lock;
74};
75
76static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm)
77{
78 struct platform_device *pdev = to_platform_device(dev);
79 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
80 void __iomem *ioaddr = pdata->ioaddr;
81 u8 century;
82
83 century = bin2bcd((tm->tm_year + 1900) / 100);
84
85 writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
86
87 writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
88 writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
89 writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
90 writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
91 writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
92 writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
93 writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
94
95
96 writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
97 writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
98 return 0;
99}
100
101static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm)
102{
103 struct platform_device *pdev = to_platform_device(dev);
104 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
105 void __iomem *ioaddr = pdata->ioaddr;
106 unsigned int year, month, day, hour, minute, second, week;
107 unsigned int century;
108
109
110 if (pdata->last_jiffies == jiffies)
111 msleep(1);
112 pdata->last_jiffies = jiffies;
113 writeb(RTC_READ, ioaddr + RTC_CONTROL);
114 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
115 minute = readb(ioaddr + RTC_MINUTES);
116 hour = readb(ioaddr + RTC_HOURS);
117 day = readb(ioaddr + RTC_DATE);
118 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
119 month = readb(ioaddr + RTC_MONTH);
120 year = readb(ioaddr + RTC_YEAR);
121 century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
122 writeb(0, ioaddr + RTC_CONTROL);
123 tm->tm_sec = bcd2bin(second);
124 tm->tm_min = bcd2bin(minute);
125 tm->tm_hour = bcd2bin(hour);
126 tm->tm_mday = bcd2bin(day);
127 tm->tm_wday = bcd2bin(week);
128 tm->tm_mon = bcd2bin(month) - 1;
129
130 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
131
132 if (rtc_valid_tm(tm) < 0) {
133 dev_err(dev, "retrieved date/time is not valid.\n");
134 rtc_time_to_tm(0, tm);
135 }
136 return 0;
137}
138
139static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
140{
141 void __iomem *ioaddr = pdata->ioaddr;
142 unsigned long flags;
143
144 spin_lock_irqsave(&pdata->lock, flags);
145 writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
146 0x80 : bin2bcd(pdata->alrm_mday),
147 ioaddr + RTC_DATE_ALARM);
148 writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
149 0x80 : bin2bcd(pdata->alrm_hour),
150 ioaddr + RTC_HOURS_ALARM);
151 writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
152 0x80 : bin2bcd(pdata->alrm_min),
153 ioaddr + RTC_MINUTES_ALARM);
154 writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
155 0x80 : bin2bcd(pdata->alrm_sec),
156 ioaddr + RTC_SECONDS_ALARM);
157 writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
158 readb(ioaddr + RTC_FLAGS);
159 spin_unlock_irqrestore(&pdata->lock, flags);
160}
161
162static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
163{
164 struct platform_device *pdev = to_platform_device(dev);
165 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
166
167 if (pdata->irq <= 0)
168 return -EINVAL;
169 pdata->alrm_mday = alrm->time.tm_mday;
170 pdata->alrm_hour = alrm->time.tm_hour;
171 pdata->alrm_min = alrm->time.tm_min;
172 pdata->alrm_sec = alrm->time.tm_sec;
173 if (alrm->enabled)
174 pdata->irqen |= RTC_AF;
175 ds1553_rtc_update_alarm(pdata);
176 return 0;
177}
178
179static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
180{
181 struct platform_device *pdev = to_platform_device(dev);
182 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
183
184 if (pdata->irq <= 0)
185 return -EINVAL;
186 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
187 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
188 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
189 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
190 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
191 return 0;
192}
193
194static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
195{
196 struct platform_device *pdev = dev_id;
197 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
198 void __iomem *ioaddr = pdata->ioaddr;
199 unsigned long events = 0;
200
201 spin_lock(&pdata->lock);
202
203 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
204 events = RTC_IRQF;
205 if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
206 events |= RTC_UF;
207 else
208 events |= RTC_AF;
209 if (likely(pdata->rtc))
210 rtc_update_irq(pdata->rtc, 1, events);
211 }
212 spin_unlock(&pdata->lock);
213 return events ? IRQ_HANDLED : IRQ_NONE;
214}
215
216static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
217{
218 struct platform_device *pdev = to_platform_device(dev);
219 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
220
221 if (pdata->irq <= 0)
222 return -EINVAL;
223 if (enabled)
224 pdata->irqen |= RTC_AF;
225 else
226 pdata->irqen &= ~RTC_AF;
227 ds1553_rtc_update_alarm(pdata);
228 return 0;
229}
230
231static const struct rtc_class_ops ds1553_rtc_ops = {
232 .read_time = ds1553_rtc_read_time,
233 .set_time = ds1553_rtc_set_time,
234 .read_alarm = ds1553_rtc_read_alarm,
235 .set_alarm = ds1553_rtc_set_alarm,
236 .alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
237};
238
239static ssize_t ds1553_nvram_read(struct file *filp, struct kobject *kobj,
240 struct bin_attribute *bin_attr,
241 char *buf, loff_t pos, size_t size)
242{
243 struct device *dev = container_of(kobj, struct device, kobj);
244 struct platform_device *pdev = to_platform_device(dev);
245 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
246 void __iomem *ioaddr = pdata->ioaddr;
247 ssize_t count;
248
249 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
250 *buf++ = readb(ioaddr + pos++);
251 return count;
252}
253
254static ssize_t ds1553_nvram_write(struct file *filp, struct kobject *kobj,
255 struct bin_attribute *bin_attr,
256 char *buf, loff_t pos, size_t size)
257{
258 struct device *dev = container_of(kobj, struct device, kobj);
259 struct platform_device *pdev = to_platform_device(dev);
260 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
261 void __iomem *ioaddr = pdata->ioaddr;
262 ssize_t count;
263
264 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
265 writeb(*buf++, ioaddr + pos++);
266 return count;
267}
268
269static struct bin_attribute ds1553_nvram_attr = {
270 .attr = {
271 .name = "nvram",
272 .mode = S_IRUGO | S_IWUSR,
273 },
274 .size = RTC_OFFSET,
275 .read = ds1553_nvram_read,
276 .write = ds1553_nvram_write,
277};
278
279static int ds1553_rtc_probe(struct platform_device *pdev)
280{
281 struct rtc_device *rtc;
282 struct resource *res;
283 unsigned int cen, sec;
284 struct rtc_plat_data *pdata;
285 void __iomem *ioaddr;
286 int ret = 0;
287
288 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
289 if (!pdata)
290 return -ENOMEM;
291
292 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
293 ioaddr = devm_ioremap_resource(&pdev->dev, res);
294 if (IS_ERR(ioaddr))
295 return PTR_ERR(ioaddr);
296 pdata->ioaddr = ioaddr;
297 pdata->irq = platform_get_irq(pdev, 0);
298
299
300 sec = readb(ioaddr + RTC_SECONDS);
301 if (sec & RTC_STOP) {
302 sec &= RTC_SECONDS_MASK;
303 cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
304 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
305 writeb(sec, ioaddr + RTC_SECONDS);
306 writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
307 }
308 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
309 dev_warn(&pdev->dev, "voltage-low detected.\n");
310
311 spin_lock_init(&pdata->lock);
312 pdata->last_jiffies = jiffies;
313 platform_set_drvdata(pdev, pdata);
314 if (pdata->irq > 0) {
315 writeb(0, ioaddr + RTC_INTERRUPTS);
316 if (devm_request_irq(&pdev->dev, pdata->irq,
317 ds1553_rtc_interrupt,
318 0, pdev->name, pdev) < 0) {
319 dev_warn(&pdev->dev, "interrupt not available.\n");
320 pdata->irq = 0;
321 }
322 }
323
324 rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
325 &ds1553_rtc_ops, THIS_MODULE);
326 if (IS_ERR(rtc))
327 return PTR_ERR(rtc);
328 pdata->rtc = rtc;
329
330 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
331
332 return ret;
333}
334
335static int ds1553_rtc_remove(struct platform_device *pdev)
336{
337 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
338
339 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
340 if (pdata->irq > 0)
341 writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
342 return 0;
343}
344
345
346MODULE_ALIAS("platform:rtc-ds1553");
347
348static struct platform_driver ds1553_rtc_driver = {
349 .probe = ds1553_rtc_probe,
350 .remove = ds1553_rtc_remove,
351 .driver = {
352 .name = "rtc-ds1553",
353 .owner = THIS_MODULE,
354 },
355};
356
357module_platform_driver(ds1553_rtc_driver);
358
359MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
360MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
361MODULE_LICENSE("GPL");
362MODULE_VERSION(DRV_VERSION);
363
