[PATCH] knfsd: nfsd4: fix corruption on readdir encoding with 64k pages
[linux-2.6] / drivers / rtc / rtc-pcf8563.c
1 /*
2  * An I2C driver for the Philips PCF8563 RTC
3  * Copyright 2005-06 Tower Technologies
4  *
5  * Author: Alessandro Zummo <a.zummo@towertech.it>
6  * Maintainers: http://www.nslu2-linux.org/
7  *
8  * based on the other drivers in this same directory.
9  *
10  * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16
17 #include <linux/i2c.h>
18 #include <linux/bcd.h>
19 #include <linux/rtc.h>
20
21 #define DRV_VERSION "0.4.2"
22
23 /* Addresses to scan: none
24  * This chip cannot be reliably autodetected. An empty eeprom
25  * located at 0x51 will pass the validation routine due to
26  * the way the registers are implemented.
27  */
28 static unsigned short normal_i2c[] = { I2C_CLIENT_END };
29
30 /* Module parameters */
31 I2C_CLIENT_INSMOD;
32
33 #define PCF8563_REG_ST1         0x00 /* status */
34 #define PCF8563_REG_ST2         0x01
35
36 #define PCF8563_REG_SC          0x02 /* datetime */
37 #define PCF8563_REG_MN          0x03
38 #define PCF8563_REG_HR          0x04
39 #define PCF8563_REG_DM          0x05
40 #define PCF8563_REG_DW          0x06
41 #define PCF8563_REG_MO          0x07
42 #define PCF8563_REG_YR          0x08
43
44 #define PCF8563_REG_AMN         0x09 /* alarm */
45 #define PCF8563_REG_AHR         0x0A
46 #define PCF8563_REG_ADM         0x0B
47 #define PCF8563_REG_ADW         0x0C
48
49 #define PCF8563_REG_CLKO        0x0D /* clock out */
50 #define PCF8563_REG_TMRC        0x0E /* timer control */
51 #define PCF8563_REG_TMR         0x0F /* timer */
52
53 #define PCF8563_SC_LV           0x80 /* low voltage */
54 #define PCF8563_MO_C            0x80 /* century */
55
56 static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind);
57 static int pcf8563_detach(struct i2c_client *client);
58
59 /*
60  * In the routines that deal directly with the pcf8563 hardware, we use
61  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
62  */
63 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
64 {
65         unsigned char buf[13] = { PCF8563_REG_ST1 };
66
67         struct i2c_msg msgs[] = {
68                 { client->addr, 0, 1, buf },    /* setup read ptr */
69                 { client->addr, I2C_M_RD, 13, buf },    /* read status + date */
70         };
71
72         /* read registers */
73         if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
74                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
75                 return -EIO;
76         }
77
78         if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
79                 dev_info(&client->dev,
80                         "low voltage detected, date/time is not reliable.\n");
81
82         dev_dbg(&client->dev,
83                 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
84                 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
85                 __FUNCTION__,
86                 buf[0], buf[1], buf[2], buf[3],
87                 buf[4], buf[5], buf[6], buf[7],
88                 buf[8]);
89
90
91         tm->tm_sec = BCD2BIN(buf[PCF8563_REG_SC] & 0x7F);
92         tm->tm_min = BCD2BIN(buf[PCF8563_REG_MN] & 0x7F);
93         tm->tm_hour = BCD2BIN(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
94         tm->tm_mday = BCD2BIN(buf[PCF8563_REG_DM] & 0x3F);
95         tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
96         tm->tm_mon = BCD2BIN(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
97         tm->tm_year = BCD2BIN(buf[PCF8563_REG_YR])
98                 + (buf[PCF8563_REG_MO] & PCF8563_MO_C ? 100 : 0);
99
100         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
101                 "mday=%d, mon=%d, year=%d, wday=%d\n",
102                 __FUNCTION__,
103                 tm->tm_sec, tm->tm_min, tm->tm_hour,
104                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
105
106         /* the clock can give out invalid datetime, but we cannot return
107          * -EINVAL otherwise hwclock will refuse to set the time on bootup.
108          */
109         if (rtc_valid_tm(tm) < 0)
110                 dev_err(&client->dev, "retrieved date/time is not valid.\n");
111
112         return 0;
113 }
114
115 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
116 {
117         int i, err;
118         unsigned char buf[9];
119
120         dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
121                 "mday=%d, mon=%d, year=%d, wday=%d\n",
122                 __FUNCTION__,
123                 tm->tm_sec, tm->tm_min, tm->tm_hour,
124                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
125
126         /* hours, minutes and seconds */
127         buf[PCF8563_REG_SC] = BIN2BCD(tm->tm_sec);
128         buf[PCF8563_REG_MN] = BIN2BCD(tm->tm_min);
129         buf[PCF8563_REG_HR] = BIN2BCD(tm->tm_hour);
130
131         buf[PCF8563_REG_DM] = BIN2BCD(tm->tm_mday);
132
133         /* month, 1 - 12 */
134         buf[PCF8563_REG_MO] = BIN2BCD(tm->tm_mon + 1);
135
136         /* year and century */
137         buf[PCF8563_REG_YR] = BIN2BCD(tm->tm_year % 100);
138         if (tm->tm_year / 100)
139                 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
140
141         buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
142
143         /* write register's data */
144         for (i = 0; i < 7; i++) {
145                 unsigned char data[2] = { PCF8563_REG_SC + i,
146                                                 buf[PCF8563_REG_SC + i] };
147
148                 err = i2c_master_send(client, data, sizeof(data));
149                 if (err != sizeof(data)) {
150                         dev_err(&client->dev,
151                                 "%s: err=%d addr=%02x, data=%02x\n",
152                                 __FUNCTION__, err, data[0], data[1]);
153                         return -EIO;
154                 }
155         };
156
157         return 0;
158 }
159
160 struct pcf8563_limit
161 {
162         unsigned char reg;
163         unsigned char mask;
164         unsigned char min;
165         unsigned char max;
166 };
167
168 static int pcf8563_validate_client(struct i2c_client *client)
169 {
170         int i;
171
172         static const struct pcf8563_limit pattern[] = {
173                 /* register, mask, min, max */
174                 { PCF8563_REG_SC,       0x7F,   0,      59      },
175                 { PCF8563_REG_MN,       0x7F,   0,      59      },
176                 { PCF8563_REG_HR,       0x3F,   0,      23      },
177                 { PCF8563_REG_DM,       0x3F,   0,      31      },
178                 { PCF8563_REG_MO,       0x1F,   0,      12      },
179         };
180
181         /* check limits (only registers with bcd values) */
182         for (i = 0; i < ARRAY_SIZE(pattern); i++) {
183                 int xfer;
184                 unsigned char value;
185                 unsigned char buf = pattern[i].reg;
186
187                 struct i2c_msg msgs[] = {
188                         { client->addr, 0, 1, &buf },
189                         { client->addr, I2C_M_RD, 1, &buf },
190                 };
191
192                 xfer = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
193
194                 if (xfer != ARRAY_SIZE(msgs)) {
195                         dev_err(&client->adapter->dev,
196                                 "%s: could not read register 0x%02X\n",
197                                 __FUNCTION__, pattern[i].reg);
198
199                         return -EIO;
200                 }
201
202                 value = BCD2BIN(buf & pattern[i].mask);
203
204                 if (value > pattern[i].max ||
205                         value < pattern[i].min) {
206                         dev_dbg(&client->adapter->dev,
207                                 "%s: pattern=%d, reg=%x, mask=0x%02x, min=%d, "
208                                 "max=%d, value=%d, raw=0x%02X\n",
209                                 __FUNCTION__, i, pattern[i].reg, pattern[i].mask,
210                                 pattern[i].min, pattern[i].max,
211                                 value, buf);
212
213                         return -ENODEV;
214                 }
215         }
216
217         return 0;
218 }
219
220 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
221 {
222         return pcf8563_get_datetime(to_i2c_client(dev), tm);
223 }
224
225 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
226 {
227         return pcf8563_set_datetime(to_i2c_client(dev), tm);
228 }
229
230 static struct rtc_class_ops pcf8563_rtc_ops = {
231         .read_time      = pcf8563_rtc_read_time,
232         .set_time       = pcf8563_rtc_set_time,
233 };
234
235 static int pcf8563_attach(struct i2c_adapter *adapter)
236 {
237         return i2c_probe(adapter, &addr_data, pcf8563_probe);
238 }
239
240 static struct i2c_driver pcf8563_driver = {
241         .driver         = {
242                 .name   = "pcf8563",
243         },
244         .id             = I2C_DRIVERID_PCF8563,
245         .attach_adapter = &pcf8563_attach,
246         .detach_client  = &pcf8563_detach,
247 };
248
249 static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind)
250 {
251         struct i2c_client *client;
252         struct rtc_device *rtc;
253
254         int err = 0;
255
256         dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
257
258         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
259                 err = -ENODEV;
260                 goto exit;
261         }
262
263         if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
264                 err = -ENOMEM;
265                 goto exit;
266         }
267
268         client->addr = address;
269         client->driver = &pcf8563_driver;
270         client->adapter = adapter;
271
272         strlcpy(client->name, pcf8563_driver.driver.name, I2C_NAME_SIZE);
273
274         /* Verify the chip is really an PCF8563 */
275         if (kind < 0) {
276                 if (pcf8563_validate_client(client) < 0) {
277                         err = -ENODEV;
278                         goto exit_kfree;
279                 }
280         }
281
282         /* Inform the i2c layer */
283         if ((err = i2c_attach_client(client)))
284                 goto exit_kfree;
285
286         dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
287
288         rtc = rtc_device_register(pcf8563_driver.driver.name, &client->dev,
289                                 &pcf8563_rtc_ops, THIS_MODULE);
290
291         if (IS_ERR(rtc)) {
292                 err = PTR_ERR(rtc);
293                 goto exit_detach;
294         }
295
296         i2c_set_clientdata(client, rtc);
297
298         return 0;
299
300 exit_detach:
301         i2c_detach_client(client);
302
303 exit_kfree:
304         kfree(client);
305
306 exit:
307         return err;
308 }
309
310 static int pcf8563_detach(struct i2c_client *client)
311 {
312         int err;
313         struct rtc_device *rtc = i2c_get_clientdata(client);
314
315         if (rtc)
316                 rtc_device_unregister(rtc);
317
318         if ((err = i2c_detach_client(client)))
319                 return err;
320
321         kfree(client);
322
323         return 0;
324 }
325
326 static int __init pcf8563_init(void)
327 {
328         return i2c_add_driver(&pcf8563_driver);
329 }
330
331 static void __exit pcf8563_exit(void)
332 {
333         i2c_del_driver(&pcf8563_driver);
334 }
335
336 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
337 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
338 MODULE_LICENSE("GPL");
339 MODULE_VERSION(DRV_VERSION);
340
341 module_init(pcf8563_init);
342 module_exit(pcf8563_exit);