2 x1205 - an 12c driver for the Xicor X1205 RTC
3 Copyright 2004 Karen Spearel
5 please send all reports to:
6 kas11 at tampabay dot rr dot com
8 based on linux/drivers/acron/char/pcf8583.h
9 Copyright (C) 2000 Russell King
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2 of the License, or
14 (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 * i2c_adapter is the structure used to identify a physical i2c bus along
28 * with the access algorithms necessary to access it.
32 unsigned int id; == is algo->id | hwdep.struct->id, for registered values see below
34 struct i2c_algorithm *algo; the algorithm to access the bus
37 --- administration stuff.
38 int (*client_register)(struct i2c_client *);
39 int (*client_unregister)(struct i2c_client *);
41 data fields that are valid for all devices
42 struct semaphore bus_lock;
43 struct semaphore clist_lock;
47 struct device dev; the adapter device
48 struct class_device class_dev; the class device
51 No need to set this when you initialize the adapter
53 #endif def CONFIG_PROC_FS
56 struct list_head clients;
57 struct list_head list;
58 char name[I2C_NAME_SIZE];
59 struct completion dev_released;
60 struct completion class_dev_released;
65 /*========== Driver for the X1205 on the Linksys NSLU2 ==================*/
67 #include <linux/init.h>
68 #include <linux/i2c.h>
69 #include <linux/slab.h>
70 #include <linux/string.h>
71 #include <linux/errno.h>
72 #include <linux/bcd.h>
73 #include <linux/rtc.h>
75 #include <linux/proc_fs.h>
76 #include <linux/miscdevice.h>
77 #include <linux/device.h>
78 #include <asm/uaccess.h>
79 #include <asm/system.h>
80 #include <linux/moduleparam.h>
82 #define RTC_GETDATETIME 0
84 #define RTC_SETDATETIME 2
86 #define I2C_M_WR 0 // just for consistancy
88 // offsets into read buf - add 2 for write buf
98 #define X1205_I2C_BUS_ADDR 0x6f // hardwired into x1205
99 #define X1205_ALM0_BASE 0x00 // Base address of the ALM0
100 #define X1205_CCR_BASE 0x30 // Base address of the CCR
101 #define X1205_SR_ADDR 0x3f // Status Register
102 #define X1205_SR_WEL 0x02 // Write Enable Latch bit
103 #define X1205_SR_RWEL 0x04 // Register Write Enable Bit
104 #define X1205_MILBIT 0x80 // this bit set in ccr.hour for 24 hr mode
107 #define RTC_DATETOO 1
109 // comment out next line is your x1205 can't do page writes
110 //#define X1205PAGEWRITE 1
111 #ifdef X1205PAGEWRITE
112 #define DRIVERNAME "Xicor x1205 RTC Driver v0.9.3.3"
114 #define DRIVERNAME "Xicor x1205 RTC Dvr v0.9.3.3NPW"
117 #define DEBUG KERN_DEBUG
120 static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm, u8 reg_base);
121 static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm, int datetoo, u8 reg_base);
122 static int x1205_attach(struct i2c_adapter *adapter);
123 static int x1205_detach(struct i2c_client *client);
124 static int x1205_validate_tm(struct rtc_time *tm);
125 static int x1205_command(struct i2c_client *client, unsigned int cmd, void *arg);
126 static int x1205_sync_rtc(void);
127 static int x1205_read(struct file *file, char *buf, size_t count, loff_t *ptr);
128 static int x1205_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
129 static int x1205_read_proc(char *buf, char **start, off_t off, int len, int *eof, void *data);
131 static struct i2c_driver x1205_driver = {
132 .owner = THIS_MODULE,
134 .id = I2C_DRIVERID_X1205,
135 .flags = I2C_DF_NOTIFY,
136 .attach_adapter = &x1205_attach, //we don't need to probe...x1205 is hardwired @ 0x6f
137 .detach_client = &x1205_detach,
138 .command = &x1205_command, //this prolly never gets called...used internally tho
141 static struct i2c_client x1205_i2c_client = {
142 .id = I2C_DRIVERID_X1205,
144 .addr = X1205_I2C_BUS_ADDR, // chip address - NOTE: 7bit
145 .adapter = NULL, // the adapter we sit on assigned in attach
146 .driver = &x1205_driver, // and our access routines
147 .usage_count = 0, // How many accesses currently to this client
148 .dev = {}, // the device structure
154 static struct file_operations rtc_fops = {
160 static struct miscdevice x1205_miscdev = {
165 extern int (*set_rtc)(void);
166 static unsigned epoch = 1900; //coresponds to year 0
167 static unsigned rtc_epoch = 2000;
168 static const unsigned char days_in_mo[] =
169 {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
171 //===================================CODE======================================
172 // in the routines that deal directly with the x1205 hardware, we use
173 // rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
174 // Epoch is inited as 2000. Time is set to UT
175 //=============================================================================
176 static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm, u8 reg_base)
178 static unsigned char addr[2] = { 0,} ;
179 unsigned char buf[8];
180 struct i2c_msg msgs[2] = {
181 { client->addr, I2C_M_WR, 2, addr }, //msg 1 = send base address
182 { client->addr, I2C_M_RD, 8, buf }, //msg 2 = read sequential data
185 if ((i2c_transfer(client->adapter, msgs, 2)) == 2) { //did we read 2 messages?
186 printk(KERN_DEBUG "raw x1205 read data - sec-%02x min-%02x hr-%02x mday-%02x mon-%02x year-%02x wday-%02x y2k-%02x\n",
187 buf[0],buf[1],buf[2],buf[3],buf[4],buf[5],buf[6], buf[7]);
188 tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
189 tm->tm_min = BCD2BIN(buf[CCR_MIN]);
190 buf[CCR_HOUR] &= ~X1205_MILBIT;
191 tm->tm_hour = BCD2BIN(buf[CCR_HOUR]); //hr is 0-23
192 tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
193 tm->tm_mon = BCD2BIN(buf[CCR_MONTH]);
194 rtc_epoch = BCD2BIN(buf[CCR_Y2K]) * 100;
195 tm->tm_year = BCD2BIN(buf[CCR_YEAR]) + rtc_epoch - epoch;
196 tm->tm_wday = buf[CCR_WDAY];
197 printk(KERN_DEBUG "rtc_time output data - sec-%02d min-%02d hr-%02d mday-%02d mon-%02d year-%02d wday-%02d epoch-%d rtc_epoch-%d\n",
198 tm->tm_sec,tm->tm_min,tm->tm_hour,tm->tm_mday,tm->tm_mon,tm->tm_year,tm->tm_wday,epoch, rtc_epoch);
200 printk(KERN_DEBUG "i2c_transfer Read Error\n");
206 // x1205pagewrite allows writing a block of registers in msg3 even though the x1205 says
207 // nothing about this in its spec.
208 // it needs more testing as it is possible some x1205s are actually not-completely-
209 // functional x1226s and there is a reason for the multiple write to not be in the spec.
210 // anyhow, it is enabled for the time being...and we even push out luck by sending 10 bytes
212 static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm, int datetoo, u8 reg_base)
214 static unsigned char wel[3] = { 0, X1205_SR_ADDR, X1205_SR_WEL };
215 static unsigned char rwel[3] = { 0, X1205_SR_ADDR, X1205_SR_WEL | X1205_SR_RWEL };
216 static unsigned char diswe[3] = { 0, X1205_SR_ADDR, 0 };
218 #ifdef X1205PAGEWRITE
220 static unsigned char buf[10] = { 0, X1205_CCR_BASE, };
221 struct i2c_msg msgs[4] = {
222 { client->addr, I2C_M_WR, 3, wel }, //msg 1 = write WEL to to ccr sr
223 { client->addr, I2C_M_WR, 3, rwel }, //msg 2 = write RWEL to ccr sr
224 { client->addr, I2C_M_WR, 10, buf }, //msg 3 = write ccr base addr +seq data
225 { client->addr, I2C_M_WR, 3, diswe }, //msg 4 = 0 to ccr sr to disable writes
228 msgs[2].len = 5; // 5 bytes + addr to set time only
230 buf[CCR_SEC+2] = BIN2BCD(tm->tm_sec);
231 buf[CCR_MIN+2] = BIN2BCD(tm->tm_min);
232 buf[CCR_HOUR+2] = BIN2BCD(tm->tm_hour) | X1205_MILBIT; // set 24 hour format
234 buf[CCR_MDAY+2] = BIN2BCD(tm->tm_mday);
235 buf[CCR_MONTH+2] = BIN2BCD(tm->tm_mon); // input is 0-11
236 buf[CCR_YEAR+2] = BIN2BCD((tm->tm_year + epoch - rtc_epoch)); // input is yrs since 1900
237 buf[CCR_WDAY+2] = tm->tm_wday & 7;
238 buf[CCR_Y2K+2] = BIN2BCD((rtc_epoch/100));
239 msgs[2].len += 5; //5 more bytes to set date
241 printk(KERN_DEBUG "rtc_time input - sec-%02d min-%02d hour-%02d mday-%02d mon-%02d year-%02d wday-%02d epoch-%d rtc_epoch-%d\n",
242 tm->tm_sec,tm->tm_min,tm->tm_hour,tm->tm_mday,tm->tm_mon,tm->tm_year,tm->tm_wday, epoch, rtc_epoch);
243 printk(KERN_DEBUG "BCD write data - sec-%02x min-%02x hour-%02x mday-%02x mon-%02x year-%02x wday-%02x y2k-%02x\n",
244 buf[2],buf[3],buf[4],buf[5],buf[6], buf[7], buf[8], buf[9]);
246 if ((i2c_transfer(client->adapter, msgs, 4)) != 4)
250 #else //do this if page writes aren't working
253 static unsigned char data[3] = { 0,};
254 static unsigned char buf[8];
256 buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
257 buf[CCR_MIN] = BIN2BCD(tm->tm_min);
258 buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_MILBIT; // set 24 hour format
260 buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
261 buf[CCR_MONTH] = BIN2BCD(tm->tm_mon); // input is 0-11
262 buf[CCR_YEAR] = BIN2BCD((tm->tm_year + epoch - rtc_epoch)); // input is yrs since 1900
263 buf[CCR_WDAY] = tm->tm_wday & 7;
264 buf[CCR_Y2K] = BIN2BCD((rtc_epoch/100));
266 printk(KERN_DEBUG "rtc_time input - sec-%02d min-%02d hour-%02d mday-%02d mon-%02d year-%02d wday-%02d epoch-%d rtc_epoch-%d\n",
267 tm->tm_sec,tm->tm_min,tm->tm_hour,tm->tm_mday,tm->tm_mon,tm->tm_year,tm->tm_wday, epoch, rtc_epoch);
269 xfer = i2c_master_send(client, wel, 3);
270 printk(KERN_DEBUG "wen - %x\n", xfer);
274 xfer = i2c_master_send(client, rwel, 3);
275 printk(KERN_DEBUG "wenb - %x\n", xfer);
279 for (i = 0; i < 8; i++) {
280 data[1] = i + reg_base;
282 xfer = i2c_master_send(client, data, 3);
283 printk(KERN_DEBUG "xfer - %d addr - %02x data - %02x\n", xfer, data[1], data[2]);
288 xfer = i2c_master_send(client, diswe, 3);
289 printk(KERN_DEBUG "wdis - %x\n", xfer);
295 //=============================================================================
297 static int x1205_attach(struct i2c_adapter *adapter)
303 x1205_i2c_client.adapter = adapter;
304 x1205_i2c_client.id++;
306 if ((x1205_get_datetime(&x1205_i2c_client, &tm, X1205_CCR_BASE)) != NOERR) //test for functional driver
309 if ((errno = i2c_attach_client(&x1205_i2c_client)) != NOERR)
312 tv.tv_nsec = tm.tm_sec * 10000000;
313 tv.tv_sec = mktime(tm.tm_year+epoch, tm.tm_mon, tm.tm_mday, tm.tm_hour,
314 tm.tm_min, tm.tm_sec);
315 do_settimeofday(&tv);
316 set_rtc = x1205_sync_rtc;
318 printk(KERN_DEBUG "%s attached on adapter %s\n",x1205_i2c_client.name,
319 x1205_i2c_client.adapter->name); //why is this name a null string?
324 static int x1205_detach(struct i2c_client *client)
328 if ((errno = i2c_detach_client(client)) != 0) {
329 printk(KERN_DEBUG "i2c_detach failed - errno = %d\n", errno);
336 // make sure the rtc_time values are in bounds
337 static int x1205_validate_tm(struct rtc_time *tm)
341 if (tm->tm_year < 1970)
344 if ((tm->tm_mon > 11) || (tm->tm_mday == 0))
347 if (tm->tm_mday > (days_in_mo[tm->tm_mon] + ( (tm->tm_mon == 1) &&
348 ((!(tm->tm_year % 4) && (tm->tm_year % 100) ) || !(tm->tm_year % 400)))))
351 if ((tm->tm_year -= epoch) > 255)
354 if ((tm->tm_hour >= 24) || (tm->tm_min >= 60) || (tm->tm_sec >= 60))
359 static int x1205_command(struct i2c_client *client, unsigned int cmd, void *tm)
361 int errno, dodate = RTC_DATETOO;
363 if (client == NULL || tm == NULL)
365 if (!capable(CAP_SYS_TIME))
368 printk(KERN_DEBUG "x1205_command %d\n", cmd);
371 case RTC_GETDATETIME:
372 return x1205_get_datetime(client, tm, X1205_CCR_BASE);
374 case RTC_SETTIME: // note fall thru
376 case RTC_SETDATETIME:
377 if ((errno = x1205_validate_tm(tm)) < NOERR)
379 return x1205_set_datetime(client, tm, dodate, X1205_CCR_BASE);
386 static int x1205_sync_rtc(void)
388 struct rtc_time new_tm, old_tm;
389 unsigned long cur_secs = xtime.tv_sec;
391 printk(KERN_DEBUG "x1205_sync_rtc entry\n");
393 if (x1205_command(&x1205_i2c_client, RTC_GETDATETIME, &old_tm))
396 // xtime.tv_nsec = old_tm.tm_sec * 10000000; //FIXME:
397 new_tm.tm_sec = cur_secs % 60;
399 new_tm.tm_min = cur_secs % 60;
401 new_tm.tm_hour = cur_secs % 24;
404 * avoid writing when we're going to change the day
405 * of the month. We will retry in the next minute.
406 * This basically means that if the RTC must not drift
407 * by more than 1 minute in 11 minutes.
409 if ((old_tm.tm_hour == 23 && old_tm.tm_min == 59) ||
410 (new_tm.tm_hour == 23 && new_tm.tm_min == 59))
412 printk(KERN_DEBUG "x1205_sync_rtc exit\n");
414 return x1205_command(&x1205_i2c_client, RTC_SETTIME, &new_tm);
417 static int x1205_read(struct file *file, char *buf, size_t count, loff_t *ptr)
421 if ((x1205_get_datetime(&x1205_i2c_client, &tm, X1205_CCR_BASE)) < NOERR)
423 return copy_to_user(buf, &tm, sizeof(tm)) ? -EFAULT : NOERR;
426 //==============================================================================
428 static int x1205_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
434 printk(KERN_DEBUG "ioctl = %x\n", cmd);
438 if ((x1205_get_datetime(&x1205_i2c_client, &tm, X1205_CCR_BASE)) < NOERR)
443 if (!capable(CAP_SYS_TIME))
446 if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof(struct rtc_time)))
448 if ((errno = x1205_validate_tm(&tm)) < NOERR)
450 return x1205_set_datetime(&x1205_i2c_client, &tm, RTC_DATETOO, X1205_CCR_BASE);
452 case RTC_ALM_SET: //FIXME: set Control Regs
453 if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof(struct rtc_time)))
455 return x1205_set_datetime(&x1205_i2c_client, &tm, RTC_DATETOO, X1205_ALM0_BASE);
458 if ((x1205_get_datetime(&x1205_i2c_client, &tm, X1205_ALM0_BASE)) < NOERR)
464 return put_user (epoch, (unsigned long __user *)arg);
470 if (!capable(CAP_SYS_TIME))
479 return copy_to_user((void __user *)arg, &tm, sizeof tm) ? -EFAULT : 0;
483 static int x1205_read_proc(char *buf, char **start, off_t off, int len, int *eof, void *data)
488 if ((errno = x1205_get_datetime(&x1205_i2c_client, &tm, X1205_CCR_BASE)) < NOERR)
491 // here we return the real year and the month as 1-12 since it is human-readable
492 slen = sprintf(buf, "rtc_time\t: %02d:%02d:%02d\nrtc_date\t: %04d-%02d-%02d\n",
493 tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_year + 1900, tm.tm_mon+1, tm.tm_mday);
494 printk(KERN_DEBUG "raw rtc_time\t: %02d:%02d:%02d\nraw rtc_date\t: %04d-%02d-%02d\n",
495 tm.tm_hour, tm.tm_min, tm.tm_sec, tm.tm_year, tm.tm_mon, tm.tm_mday);
497 if (slen <= off + len)
509 static int __init x1205_init(void)
513 printk(KERN_INFO "LOADED %s\n", DRIVERNAME);
515 if ((errno = i2c_add_driver(&x1205_driver)) != NOERR) {
516 dev_dbg(x1205_i2c_client.dev, "x1205_init failed - errno = %d\n", errno);
519 if ((errno = misc_register(&x1205_miscdev)) != NOERR) {
520 dev_dbg(x1205_i2c_client.dev, "Register Misc Driver failed - errno = %d\n", errno);
521 i2c_del_driver(&x1205_driver);
524 if (create_proc_read_entry("driver/rtc", 0, NULL, x1205_read_proc, NULL) < NOERR)
526 if ((x1205_get_datetime(&x1205_i2c_client, &tm, X1205_CCR_BASE)) != NOERR) //test for functionality
532 static void __exit x1205_exit(void)
534 remove_proc_entry("driver/rtc", NULL);
535 misc_deregister(&x1205_miscdev);
536 i2c_del_driver(&x1205_driver);
540 MODULE_AUTHOR("Karen Spearel <kas11@tampabay.rr.com>");
541 MODULE_DESCRIPTION("Xicor X1205-RTC Driver");
542 MODULE_LICENSE("GPL");
543 static int debug = 7;
544 module_param(debug, bool, 0644);
545 MODULE_PARM_DESC(debug, "Debugging enabled = 1");
547 module_init(x1205_init);
548 module_exit(x1205_exit);