Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  *  linux/drivers/i2c/chips/rtc8564.c
  3  *
  4  *  Copyright (C) 2002-2004 Stefan Eletzhofer
  5  *
  6  *      based on linux/drivers/acron/char/pcf8583.c
  7  *  Copyright (C) 2000 Russell King
  8  *
  9  * This program is free software; you can redistribute it and/or modify
 10  * it under the terms of the GNU General Public License version 2 as
 11  * published by the Free Software Foundation.
 12  *
 13  * Driver for system3's EPSON RTC 8564 chip
 14  */
 15 #include <linux/module.h>
 16 #include <linux/kernel.h>
 17 #include <linux/i2c.h>
 18 #include <linux/slab.h>
 19 #include <linux/string.h>
 20 #include <linux/rtc.h>          /* get the user-level API */
 21 #include <linux/init.h>
 22 #include <linux/init.h>
 23 
 24 #include "rtc8564.h"
 25 
 26 #ifdef DEBUG
 27 # define _DBG(x, fmt, args...) do{ if (debug>=x) printk(KERN_DEBUG"%s: " fmt "\n", __FUNCTION__, ##args); } while(0);
 28 #else
 29 # define _DBG(x, fmt, args...) do { } while(0);
 30 #endif
 31 
 32 #define _DBGRTCTM(x, rtctm) if (debug>=x) printk("%s: secs=%d, mins=%d, hours=%d, mday=%d, " \
 33                         "mon=%d, year=%d, wday=%d VL=%d\n", __FUNCTION__, \
 34                         (rtctm).secs, (rtctm).mins, (rtctm).hours, (rtctm).mday, \
 35                         (rtctm).mon, (rtctm).year, (rtctm).wday, (rtctm).vl);
 36 
 37 struct rtc8564_data {
 38         struct i2c_client client;
 39         u16 ctrl;
 40 };
 41 
 42 static inline u8 _rtc8564_ctrl1(struct i2c_client *client)
 43 {
 44         struct rtc8564_data *data = i2c_get_clientdata(client);
 45         return data->ctrl & 0xff;
 46 }
 47 static inline u8 _rtc8564_ctrl2(struct i2c_client *client)
 48 {
 49         struct rtc8564_data *data = i2c_get_clientdata(client);
 50         return (data->ctrl & 0xff00) >> 8;
 51 }
 52 
 53 #define CTRL1(c) _rtc8564_ctrl1(c)
 54 #define CTRL2(c) _rtc8564_ctrl2(c)
 55 
 56 #define BCD_TO_BIN(val) (((val)&15) + ((val)>>4)*10)
 57 #define BIN_TO_BCD(val) ((((val)/10)<<4) + (val)%10)
 58 
 59 static int debug;;
 60 module_param(debug, int, S_IRUGO | S_IWUSR);
 61 
 62 static struct i2c_driver rtc8564_driver;
 63 
 64 static unsigned short ignore[] = { I2C_CLIENT_END };
 65 static unsigned short normal_addr[] = { 0x51, I2C_CLIENT_END };
 66 
 67 static struct i2c_client_address_data addr_data = {
 68         .normal_i2c             = normal_addr,
 69         .normal_i2c_range       = ignore,
 70         .probe                  = ignore,
 71         .probe_range            = ignore,
 72         .ignore                 = ignore,
 73         .ignore_range           = ignore,
 74         .force                  = ignore,
 75 };
 76 
 77 static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem);
 78 static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem);
 79 
 80 static int rtc8564_read(struct i2c_client *client, unsigned char adr,
 81                         unsigned char *buf, unsigned char len)
 82 {
 83         int ret = -EIO;
 84         unsigned char addr[1] = { adr };
 85         struct i2c_msg msgs[2] = {
 86                 {client->addr, 0, 1, addr},
 87                 {client->addr, I2C_M_RD, len, buf}
 88         };
 89 
 90         _DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, buf, len);
 91 
 92         if (!buf || !client) {
 93                 ret = -EINVAL;
 94                 goto done;
 95         }
 96 
 97         ret = i2c_transfer(client->adapter, msgs, 2);
 98         if (ret == 2) {
 99                 ret = 0;
100         }
101 
102 done:
103         return ret;
104 }
105 
106 static int rtc8564_write(struct i2c_client *client, unsigned char adr,
107                          unsigned char *data, unsigned char len)
108 {
109         int ret = 0;
110         unsigned char _data[16];
111         struct i2c_msg wr;
112         int i;
113 
114         if (!client || !data || len > 15) {
115                 ret = -EINVAL;
116                 goto done;
117         }
118 
119         _DBG(1, "client=%p, adr=%d, buf=%p, len=%d", client, adr, data, len);
120 
121         _data[0] = adr;
122         for (i = 0; i < len; i++) {
123                 _data[i + 1] = data[i];
124                 _DBG(5, "data[%d] = 0x%02x (%d)", i, data[i], data[i]);
125         }
126 
127         wr.addr = client->addr;
128         wr.flags = 0;
129         wr.len = len + 1;
130         wr.buf = _data;
131 
132         ret = i2c_transfer(client->adapter, &wr, 1);
133         if (ret == 1) {
134                 ret = 0;
135         }
136 
137 done:
138         return ret;
139 }
140 
141 static int rtc8564_attach(struct i2c_adapter *adap, int addr, int kind)
142 {
143         int ret;
144         struct i2c_client *new_client;
145         struct rtc8564_data *d;
146         unsigned char data[10];
147         unsigned char ad[1] = { 0 };
148         struct i2c_msg ctrl_wr[1] = {
149                 {addr, 0, 2, data}
150         };
151         struct i2c_msg ctrl_rd[2] = {
152                 {addr, 0, 1, ad},
153                 {addr, I2C_M_RD, 2, data}
154         };
155 
156         d = kmalloc(sizeof(struct rtc8564_data), GFP_KERNEL);
157         if (!d) {
158                 ret = -ENOMEM;
159                 goto done;
160         }
161         memset(d, 0, sizeof(struct rtc8564_data));
162         new_client = &d->client;
163 
164         strlcpy(new_client->name, "RTC8564", I2C_NAME_SIZE);
165         i2c_set_clientdata(new_client, d);
166         new_client->id = rtc8564_driver.id;
167         new_client->flags = I2C_CLIENT_ALLOW_USE | I2C_DF_NOTIFY;
168         new_client->addr = addr;
169         new_client->adapter = adap;
170         new_client->driver = &rtc8564_driver;
171 
172         _DBG(1, "client=%p", new_client);
173         _DBG(1, "client.id=%d", new_client->id);
174 
175         /* init ctrl1 reg */
176         data[0] = 0;
177         data[1] = 0;
178         ret = i2c_transfer(new_client->adapter, ctrl_wr, 1);
179         if (ret != 1) {
180                 printk(KERN_INFO "rtc8564: cant init ctrl1\n");
181                 ret = -ENODEV;
182                 goto done;
183         }
184 
185         /* read back ctrl1 and ctrl2 */
186         ret = i2c_transfer(new_client->adapter, ctrl_rd, 2);
187         if (ret != 2) {
188                 printk(KERN_INFO "rtc8564: cant read ctrl\n");
189                 ret = -ENODEV;
190                 goto done;
191         }
192 
193         d->ctrl = data[0] | (data[1] << 8);
194 
195         _DBG(1, "RTC8564_REG_CTRL1=%02x, RTC8564_REG_CTRL2=%02x",
196              data[0], data[1]);
197 
198         ret = i2c_attach_client(new_client);
199 done:
200         if (ret) {
201                 kfree(d);
202         }
203         return ret;
204 }
205 
206 static int rtc8564_probe(struct i2c_adapter *adap)
207 {
208         return i2c_probe(adap, &addr_data, rtc8564_attach);
209 }
210 
211 static int rtc8564_detach(struct i2c_client *client)
212 {
213         i2c_detach_client(client);
214         kfree(i2c_get_clientdata(client));
215         return 0;
216 }
217 
218 static int rtc8564_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
219 {
220         int ret = -EIO;
221         unsigned char buf[15];
222 
223         _DBG(1, "client=%p, dt=%p", client, dt);
224 
225         if (!dt || !client)
226                 return -EINVAL;
227 
228         memset(buf, 0, sizeof(buf));
229 
230         ret = rtc8564_read(client, 0, buf, 15);
231         if (ret)
232                 return ret;
233 
234         /* century stored in minute alarm reg */
235         dt->year = BCD_TO_BIN(buf[RTC8564_REG_YEAR]);
236         dt->year += 100 * BCD_TO_BIN(buf[RTC8564_REG_AL_MIN] & 0x3f);
237         dt->mday = BCD_TO_BIN(buf[RTC8564_REG_DAY] & 0x3f);
238         dt->wday = BCD_TO_BIN(buf[RTC8564_REG_WDAY] & 7);
239         dt->mon = BCD_TO_BIN(buf[RTC8564_REG_MON_CENT] & 0x1f);
240 
241         dt->secs = BCD_TO_BIN(buf[RTC8564_REG_SEC] & 0x7f);
242         dt->vl = (buf[RTC8564_REG_SEC] & 0x80) == 0x80;
243         dt->mins = BCD_TO_BIN(buf[RTC8564_REG_MIN] & 0x7f);
244         dt->hours = BCD_TO_BIN(buf[RTC8564_REG_HR] & 0x3f);
245 
246         _DBGRTCTM(2, *dt);
247 
248         return 0;
249 }
250 
251 static int
252 rtc8564_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
253 {
254         int ret, len = 5;
255         unsigned char buf[15];
256 
257         _DBG(1, "client=%p, dt=%p", client, dt);
258 
259         if (!dt || !client)
260                 return -EINVAL;
261 
262         _DBGRTCTM(2, *dt);
263 
264         buf[RTC8564_REG_CTRL1] = CTRL1(client) | RTC8564_CTRL1_STOP;
265         buf[RTC8564_REG_CTRL2] = CTRL2(client);
266         buf[RTC8564_REG_SEC] = BIN_TO_BCD(dt->secs);
267         buf[RTC8564_REG_MIN] = BIN_TO_BCD(dt->mins);
268         buf[RTC8564_REG_HR] = BIN_TO_BCD(dt->hours);
269 
270         if (datetoo) {
271                 len += 5;
272                 buf[RTC8564_REG_DAY] = BIN_TO_BCD(dt->mday);
273                 buf[RTC8564_REG_WDAY] = BIN_TO_BCD(dt->wday);
274                 buf[RTC8564_REG_MON_CENT] = BIN_TO_BCD(dt->mon) & 0x1f;
275                 /* century stored in minute alarm reg */
276                 buf[RTC8564_REG_YEAR] = BIN_TO_BCD(dt->year % 100);
277                 buf[RTC8564_REG_AL_MIN] = BIN_TO_BCD(dt->year / 100);
278         }
279 
280         ret = rtc8564_write(client, 0, buf, len);
281         if (ret) {
282                 _DBG(1, "error writing data! %d", ret);
283         }
284 
285         buf[RTC8564_REG_CTRL1] = CTRL1(client);
286         ret = rtc8564_write(client, 0, buf, 1);
287         if (ret) {
288                 _DBG(1, "error writing data! %d", ret);
289         }
290 
291         return ret;
292 }
293 
294 static int rtc8564_get_ctrl(struct i2c_client *client, unsigned int *ctrl)
295 {
296         struct rtc8564_data *data = i2c_get_clientdata(client);
297 
298         if (!ctrl || !client)
299                 return -1;
300 
301         *ctrl = data->ctrl;
302         return 0;
303 }
304 
305 static int rtc8564_set_ctrl(struct i2c_client *client, unsigned int *ctrl)
306 {
307         struct rtc8564_data *data = i2c_get_clientdata(client);
308         unsigned char buf[2];
309 
310         if (!ctrl || !client)
311                 return -1;
312 
313         buf[0] = *ctrl & 0xff;
314         buf[1] = (*ctrl & 0xff00) >> 8;
315         data->ctrl = *ctrl;
316 
317         return rtc8564_write(client, 0, buf, 2);
318 }
319 
320 static int rtc8564_read_mem(struct i2c_client *client, struct mem *mem)
321 {
322 
323         if (!mem || !client)
324                 return -EINVAL;
325 
326         return rtc8564_read(client, mem->loc, mem->data, mem->nr);
327 }
328 
329 static int rtc8564_write_mem(struct i2c_client *client, struct mem *mem)
330 {
331 
332         if (!mem || !client)
333                 return -EINVAL;
334 
335         return rtc8564_write(client, mem->loc, mem->data, mem->nr);
336 }
337 
338 static int
339 rtc8564_command(struct i2c_client *client, unsigned int cmd, void *arg)
340 {
341 
342         _DBG(1, "cmd=%d", cmd);
343 
344         switch (cmd) {
345         case RTC_GETDATETIME:
346                 return rtc8564_get_datetime(client, arg);
347 
348         case RTC_SETTIME:
349                 return rtc8564_set_datetime(client, arg, 0);
350 
351         case RTC_SETDATETIME:
352                 return rtc8564_set_datetime(client, arg, 1);
353 
354         case RTC_GETCTRL:
355                 return rtc8564_get_ctrl(client, arg);
356 
357         case RTC_SETCTRL:
358                 return rtc8564_set_ctrl(client, arg);
359 
360         case MEM_READ:
361                 return rtc8564_read_mem(client, arg);
362 
363         case MEM_WRITE:
364                 return rtc8564_write_mem(client, arg);
365 
366         default:
367                 return -EINVAL;
368         }
369 }
370 
371 static struct i2c_driver rtc8564_driver = {
372         .owner          = THIS_MODULE,
373         .name           = "RTC8564",
374         .id             = I2C_DRIVERID_RTC8564,
375         .flags          = I2C_DF_NOTIFY,
376         .attach_adapter = rtc8564_probe,
377         .detach_client  = rtc8564_detach,
378         .command        = rtc8564_command
379 };
380 
381 static __init int rtc8564_init(void)
382 {
383         return i2c_add_driver(&rtc8564_driver);
384 }
385 
386 static __exit void rtc8564_exit(void)
387 {
388         i2c_del_driver(&rtc8564_driver);
389 }
390 
391 MODULE_AUTHOR("Stefan Eletzhofer <Stefan.Eletzhofer@eletztrick.de>");
392 MODULE_DESCRIPTION("EPSON RTC8564 Driver");
393 MODULE_LICENSE("GPL");
394 
395 module_init(rtc8564_init);
396 module_exit(rtc8564_exit);
397 
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