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