[PATCH] CRIS update: drivers
[linux-2.6.git] / arch / cris / arch-v10 / drivers / pcf8563.c
1 /*
2  * PCF8563 RTC
3  *
4  * From Phillips' datasheet:
5  *
6  * The PCF8563 is a CMOS real-time clock/calendar optimized for low power
7  * consumption. A programmable clock output, interupt output and voltage
8  * low detector are also provided. All address and data are transferred
9  * serially via two-line bidirectional I2C-bus. Maximum bus speed is
10  * 400 kbits/s. The built-in word address register is incremented
11  * automatically after each written or read bute.
12  *
13  * Copyright (c) 2002, Axis Communications AB
14  * All rights reserved.
15  *
16  * Author: Tobias Anderberg <tobiasa@axis.com>.
17  *
18  * $Id: pcf8563.c,v 1.11 2005/03/07 13:13:07 starvik Exp $
19  */
20
21 #include <linux/config.h>
22 #include <linux/version.h>
23 #include <linux/module.h>
24 #include <linux/kernel.h>
25 #include <linux/types.h>
26 #include <linux/sched.h>
27 #include <linux/init.h>
28 #include <linux/fs.h>
29 #include <linux/ioctl.h>
30 #include <linux/delay.h>
31 #include <linux/bcd.h>
32
33 #include <asm/uaccess.h>
34 #include <asm/system.h>
35 #include <asm/io.h>
36 #include <asm/arch/svinto.h>
37 #include <asm/rtc.h>
38 #include "i2c.h"
39
40 #define PCF8563_MAJOR 121               /* Local major number. */
41 #define DEVICE_NAME "rtc"               /* Name which is registered in /proc/devices. */
42 #define PCF8563_NAME "PCF8563"
43 #define DRIVER_VERSION "$Revision: 1.11 $"
44
45 /* I2C bus slave registers. */
46 #define RTC_I2C_READ            0xa3
47 #define RTC_I2C_WRITE           0xa2
48
49 /* Two simple wrapper macros, saves a few keystrokes. */
50 #define rtc_read(x) i2c_readreg(RTC_I2C_READ, x)
51 #define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y)
52
53 static DEFINE_SPINLOCK(rtc_lock); /* Protect state etc */
54         
55 static const unsigned char days_in_month[] =
56         { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
57
58 int pcf8563_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
59
60 static struct file_operations pcf8563_fops = {
61         .owner = THIS_MODULE,
62         .ioctl = pcf8563_ioctl,
63 };
64
65 unsigned char
66 pcf8563_readreg(int reg) 
67 {
68         unsigned char res = i2c_readreg(RTC_I2C_READ, reg);
69
70         /* The PCF8563 does not return 0 for unimplemented bits */
71         switch(reg)
72         {
73                 case RTC_SECONDS:
74                 case RTC_MINUTES:
75                      res &= 0x7f;
76                      break;
77                 case RTC_HOURS:
78                 case RTC_DAY_OF_MONTH:
79                      res &= 0x3f;
80                      break;
81                 case RTC_MONTH:
82                      res = (res & 0x1f) - 1;  /* PCF8563 returns month in range 1-12 */
83                      break;
84         }
85         return res;
86 }
87
88 void
89 pcf8563_writereg(int reg, unsigned char val) 
90 {
91 #ifdef CONFIG_ETRAX_RTC_READONLY
92         if (reg == RTC_CONTROL1 || (reg >= RTC_SECONDS && reg <= RTC_YEAR))
93                 return;
94 #endif
95
96         rtc_write(reg, val);
97 }
98
99 void
100 get_rtc_time(struct rtc_time *tm)
101 {
102         tm->tm_sec = rtc_read(RTC_SECONDS);
103         tm->tm_min = rtc_read(RTC_MINUTES);
104         tm->tm_hour = rtc_read(RTC_HOURS);
105         tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH);
106         tm->tm_mon = rtc_read(RTC_MONTH);
107         tm->tm_year = rtc_read(RTC_YEAR);
108
109         if (tm->tm_sec & 0x80)
110                 printk(KERN_WARNING "%s: RTC Low Voltage - date/time is not reliable!\n", PCF8563_NAME);
111
112         tm->tm_year = BCD_TO_BIN(tm->tm_year) + ((tm->tm_mon & 0x80) ? 100 : 0);
113         tm->tm_sec &= 0x7f;
114         tm->tm_min &= 0x7f;
115         tm->tm_hour &= 0x3f;
116         tm->tm_mday &= 0x3f;
117         tm->tm_mon &= 0x1f;
118
119         BCD_TO_BIN(tm->tm_sec);
120         BCD_TO_BIN(tm->tm_min);
121         BCD_TO_BIN(tm->tm_hour);
122         BCD_TO_BIN(tm->tm_mday);
123         BCD_TO_BIN(tm->tm_mon);
124         tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */
125 }
126
127 int __init
128 pcf8563_init(void)
129 {
130         int ret;
131
132         if ((ret = i2c_init())) {
133                 printk(KERN_CRIT "pcf8563_init: failed to init i2c\n");
134                 return ret;
135         }
136
137         /*
138          * First of all we need to reset the chip. This is done by
139          * clearing control1, control2 and clk freq, clear the 
140          * Voltage Low bit, and resetting all alarms.
141          */
142         if (rtc_write(RTC_CONTROL1, 0x00) < 0)
143                 goto err;
144
145         if (rtc_write(RTC_CONTROL2, 0x00) < 0)
146                 goto err;
147
148         if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0)
149                 goto err;
150
151         /* Clear the VL bit in the seconds register. */
152         ret = rtc_read(RTC_SECONDS);
153         
154         if (rtc_write(RTC_SECONDS, (ret & 0x7f)) < 0)
155                 goto err;
156                 
157         /* Reset the alarms. */
158         if (rtc_write(RTC_MINUTE_ALARM, 0x00) < 0)
159                 goto err;
160         
161         if (rtc_write(RTC_HOUR_ALARM, 0x00) < 0)
162                 goto err;
163         
164         if (rtc_write(RTC_DAY_ALARM, 0x00) < 0)
165                 goto err;
166         
167         if (rtc_write(RTC_WEEKDAY_ALARM, 0x00) < 0)
168                 goto err;
169         
170         /* Check for low voltage, and warn about it.. */
171         if (rtc_read(RTC_SECONDS) & 0x80)
172                 printk(KERN_WARNING "%s: RTC Low Voltage - date/time is not reliable!\n", PCF8563_NAME);
173         
174         return 0;
175
176 err:
177         printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);
178         return -1;
179 }
180
181 void __exit
182 pcf8563_exit(void)
183 {
184         if (unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME) < 0) {
185                 printk(KERN_INFO "%s: Unable to unregister device.\n", PCF8563_NAME);
186         }
187 }
188
189 /*
190  * ioctl calls for this driver. Why return -ENOTTY upon error? Because
191  * POSIX says so!
192  */
193 int
194 pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
195 {
196         /* Some sanity checks. */
197         if (_IOC_TYPE(cmd) != RTC_MAGIC)
198                 return -ENOTTY;
199
200         if (_IOC_NR(cmd) > RTC_MAX_IOCTL)
201                 return -ENOTTY;
202
203         switch (cmd) {
204                 case RTC_RD_TIME:
205                         {
206                                 struct rtc_time tm;
207
208                                 spin_lock(&rtc_lock);
209                                 get_rtc_time(&tm);
210
211                                 if (copy_to_user((struct rtc_time *) arg, &tm, sizeof(struct rtc_time))) {
212                                         spin_unlock(&rtc_lock);
213                                         return -EFAULT;
214                                 }
215
216                                 spin_unlock(&rtc_lock);
217                                 return 0;
218                         }
219                         break;
220                 case RTC_SET_TIME:
221                         {
222 #ifdef CONFIG_ETRAX_RTC_READONLY
223                                 return -EPERM;
224 #else
225                                 int leap;
226                                 int century;
227                                 struct rtc_time tm;
228
229                                 memset(&tm, 0, sizeof (struct rtc_time));
230                                 if (!capable(CAP_SYS_TIME))
231                                         return -EPERM;
232
233                                 if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof(struct rtc_time)))
234                                         return -EFAULT;
235
236                                 /* Convert from struct tm to struct rtc_time. */
237                                 tm.tm_year += 1900;
238                                 tm.tm_mon += 1;
239                                 
240                                 leap = ((tm.tm_mon == 2) && ((tm.tm_year % 4) == 0)) ? 1 : 0;
241
242                                 /* Perform some sanity checks. */
243                                 if ((tm.tm_year < 1970) ||
244                                     (tm.tm_mon > 12) ||
245                                     (tm.tm_mday == 0) ||
246                                     (tm.tm_mday > days_in_month[tm.tm_mon] + leap) ||
247                                     (tm.tm_hour >= 24) ||
248                                     (tm.tm_min >= 60) ||
249                                     (tm.tm_sec >= 60))
250                                         return -EINVAL;
251
252                                 century = (tm.tm_year >= 2000) ? 0x80 : 0;
253                                 tm.tm_year = tm.tm_year % 100;
254
255                                 BIN_TO_BCD(tm.tm_year);
256                                 BIN_TO_BCD(tm.tm_mday);
257                                 BIN_TO_BCD(tm.tm_hour);
258                                 BIN_TO_BCD(tm.tm_min);
259                                 BIN_TO_BCD(tm.tm_sec);
260                                 tm.tm_mon |= century;
261
262                                 spin_lock(&rtc_lock);
263                                 
264                                 rtc_write(RTC_YEAR, tm.tm_year);
265                                 rtc_write(RTC_MONTH, tm.tm_mon);
266                                 rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday);
267                                 rtc_write(RTC_HOURS, tm.tm_hour);
268                                 rtc_write(RTC_MINUTES, tm.tm_min);
269                                 rtc_write(RTC_SECONDS, tm.tm_sec);
270
271                                 spin_unlock(&rtc_lock);
272
273                                 return 0;
274 #endif /* !CONFIG_ETRAX_RTC_READONLY */
275                         }
276
277                 case RTC_VLOW_RD:
278                 {
279                         int vl_bit = 0;
280
281                         if (rtc_read(RTC_SECONDS) & 0x80) {
282                                 vl_bit = 1;
283                                 printk(KERN_WARNING "%s: RTC Voltage Low - reliable "
284                                        "date/time information is no longer guaranteed!\n",
285                                        PCF8563_NAME);
286                         }
287                         if (copy_to_user((int *) arg, &vl_bit, sizeof(int)))
288                                 return -EFAULT;
289
290                         return 0;
291                 }
292
293                 case RTC_VLOW_SET:
294                 {
295                         /* Clear the VL bit in the seconds register */
296                         int ret = rtc_read(RTC_SECONDS);
297
298                         rtc_write(RTC_SECONDS, (ret & 0x7F));
299
300                         return 0;
301                 }
302
303                 default:
304                                 return -ENOTTY;
305         }
306
307         return 0;
308 }
309
310 static int __init
311 pcf8563_register(void)
312 {
313         pcf8563_init();
314         if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {
315                 printk(KERN_INFO "%s: Unable to get major numer %d for RTC device.\n",
316                        PCF8563_NAME, PCF8563_MAJOR);
317                 return -1;
318         }
319
320         printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME, DRIVER_VERSION);
321         return 0;
322 }
323
324 module_init(pcf8563_register);
325 module_exit(pcf8563_exit);