root/lm-sensors/trunk/prog/eepromer/eeprom.c @ 1745

Revision 1745, 8.3 KB (checked in by mds, 11 years ago)

update paths again to pick up userspace i2c-dev.h from

../../kernel/include

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
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1/*
2This program is hereby placed into the public domain.
3Of course the program is provided without warranty of any kind.
4*/
5#include <errno.h>
6#include <stdio.h>
7#include <stdlib.h>
8#include <unistd.h>
9#include <fcntl.h>
10#include <string.h>
11#include <time.h>
12#include "i2c-dev.h"
13
14/*
15  this program can read 24C16 (and probably smaller ones, too)
16  I wrote it as a quick and dirty hack because my satellite receiver
17  hung again... so I had to reprogram the eeprom where is stores it's
18  settings.
19 */
20
21#define DEFAULT_I2C_BUS      "/dev/i2c-0"
22#define DEFAULT_EEPROM_ADDR  0x50         /* the 24C16 sits on i2c address 0x50 */
23#define DEFAULT_NUM_PAGES    8            /* we default to a 24C16 eeprom which has 8 pages */
24#define BYTES_PER_PAGE       256          /* one eeprom page is 256 byte */
25#define MAX_BYTES            8            /* max number of bytes to write in one chunk */
26       /* ... note: 24C02 and 24C01 only allow 8 bytes to be written in one chunk.   *
27        *  if you are going to write 24C04,8,16 you can change this to 16            */
28
29/* write len bytes (stored in buf) to eeprom at address addr, page-offset offset */
30/* if len=0 (buf may be NULL in this case) you can reposition the eeprom's read-pointer */
31/* return 0 on success, -1 on failure */
32int eeprom_write(int fd,
33                 unsigned int addr,
34                 unsigned int offset,
35                 unsigned char *buf,
36                 unsigned char len
37){
38        struct i2c_rdwr_ioctl_data msg_rdwr;
39        struct i2c_msg             i2cmsg;
40        int i;
41        char _buf[MAX_BYTES + 1];
42
43        if(len>MAX_BYTES){
44            fprintf(stderr,"I can only write MAX_BYTES bytes at a time!\n");
45            return -1;
46        }
47
48        if(len+offset >256){
49            fprintf(stderr,"Sorry, len(%d)+offset(%d) > 256 (page boundary)\n",
50                        len,offset);
51            return -1;
52        }
53
54        _buf[0]=offset;    /* _buf[0] is the offset into the eeprom page! */
55        for(i=0;i<len;i++) /* copy buf[0..n] -> _buf[1..n+1] */
56            _buf[1+i]=buf[i];
57
58        msg_rdwr.msgs = &i2cmsg;
59        msg_rdwr.nmsgs = 1;
60
61        i2cmsg.addr  = addr;
62        i2cmsg.flags = 0;
63        i2cmsg.len   = 1+len;
64        i2cmsg.buf   = _buf;
65
66        if((i=ioctl(fd,I2C_RDWR,&msg_rdwr))<0){
67            perror("ioctl()");
68            fprintf(stderr,"ioctl returned %d\n",i);
69            return -1;
70        }
71
72        if(len>0)
73            fprintf(stderr,"Wrote %d bytes to eeprom at 0x%02x, offset %08x\n",
74                    len,addr,offset);
75        else
76            fprintf(stderr,"Positioned pointer in eeprom at 0x%02x to offset %08x\n",
77                    addr,offset);
78
79        return 0;
80}
81
82/* read len bytes stored in eeprom at address addr, offset offset in array buf */
83/* return -1 on error, 0 on success */
84int eeprom_read(int fd,
85                 unsigned int addr,
86                 unsigned int offset,
87                 unsigned char *buf,
88                 unsigned char len
89){
90        struct i2c_rdwr_ioctl_data msg_rdwr;
91        struct i2c_msg             i2cmsg;
92        int i;
93
94        if(len>MAX_BYTES){
95            fprintf(stderr,"I can only write MAX_BYTES bytes at a time!\n");
96            return -1;
97        }
98
99        if(eeprom_write(fd,addr,offset,NULL,0)<0)
100            return -1;
101
102        msg_rdwr.msgs = &i2cmsg;
103        msg_rdwr.nmsgs = 1;
104
105        i2cmsg.addr  = addr;
106        i2cmsg.flags = I2C_M_RD;
107        i2cmsg.len   = len;
108        i2cmsg.buf   = buf;
109
110        if((i=ioctl(fd,I2C_RDWR,&msg_rdwr))<0){
111            perror("ioctl()");
112            fprintf(stderr,"ioctl returned %d\n",i);
113            return -1;
114        }
115
116        fprintf(stderr,"Read %d bytes from eeprom at 0x%02x, offset %08x\n",
117                len,addr,offset);
118
119        return 0;
120}
121
122
123
124int main(int argc, char **argv){
125    int i,j;
126
127    /* filedescriptor and name of device */
128    int d; 
129    char *dn=DEFAULT_I2C_BUS;
130
131    /* filedescriptor and name of data file */
132    int f=-1;
133    char *fn=NULL;
134
135    unsigned int addr=DEFAULT_EEPROM_ADDR;
136    int rwmode=0;
137    int pages=DEFAULT_NUM_PAGES;
138
139    int force=0; /* suppress warning on write! */
140   
141    while((i=getopt(argc,argv,"d:a:p:wyf:h"))>=0){
142        switch(i){
143        case 'h':
144            fprintf(stderr,"%s [-d dev] [-a adr] [-p pgs] [-w] [-y] [-f file]\n",argv[0]);
145            fprintf(stderr,"\tdev: device, e.g. /dev/i2c-0    (def)\n");
146            fprintf(stderr,"\tadr: base address of eeprom, eg 0xA0 (def)\n");
147            fprintf(stderr,"\tpgs: number of pages to read, eg 8 (def)\n");
148            fprintf(stderr,"\t-w : write to eeprom (default is reading!)\n");
149            fprintf(stderr,"\t-y : suppress warning when writing (default is to warn!)\n");
150            fprintf(stderr,"\t-f file: copy eeprom contents to/from file\n");
151            fprintf(stderr,"\t         (default for read is test only; for write is all zeros)\n");
152            fprintf(stderr,"Note on pages/addresses:\n");
153            fprintf(stderr,"\teeproms with more than 256 byte appear as if they\n");
154            fprintf(stderr,"\twere several eeproms with consecutive addresses on the bus\n");
155            fprintf(stderr,"\tso we might as well address several seperate eeproms with\n");
156            fprintf(stderr,"\tincreasing addresses....\n\n");
157            exit(1);
158            break;
159        case 'd':
160            dn=optarg;
161            break;
162        case 'a':
163            if(sscanf(optarg,"0x%x",&addr)!=1){
164                fprintf(stderr,"Cannot parse '%s' as addrs., example: 0xa0\n",
165                        optarg);
166                exit(1);
167            }
168            break;
169        case 'p':
170            if(sscanf(optarg,"%d",&pages)!=1){
171                fprintf(stderr,"Cannot parse '%s' as number of pages, example: 8\n",
172                        optarg);
173                exit(1);
174            }
175            break;
176        case 'w':
177            rwmode++;
178            break;
179        case 'f':
180            fn=optarg;
181            break;
182        case 'y':
183            force++;
184            break;
185        }
186
187    }
188   
189    fprintf(stderr,"base-address of eeproms       : 0x%02x\n",addr);
190    fprintf(stderr,"number of pages to read       : %d (0x%02x .. 0x%02x)\n",
191                    pages,addr,addr+pages-1);
192
193    if(fn){
194        if(!rwmode) /* if we are reading, *WRITE* to file */
195            f=open(fn,O_WRONLY|O_CREAT,0666);
196        else /* if we are writing to eeprom, *READ* from file */
197            f=open(fn,O_RDONLY);
198        if(f<0){
199            fprintf(stderr,"Could not open data-file %s for reading or writing\n",fn);
200            perror(fn);
201            exit(1);
202        }
203        fprintf(stderr,"file opened for %7s       : %s\n",rwmode?"reading":"writing",fn);
204        fprintf(stderr,"            on filedescriptor : %d\n",f);
205    }
206
207    if((d=open(dn,O_RDWR))<0){
208        fprintf(stderr,"Could not open i2c at %s\n",dn);
209        perror(dn);
210        exit(1);
211    }
212
213    fprintf(stderr,"i2c-devicenode is             : %s\n",dn);
214    fprintf(stderr,"            on filedescriptor : %d\n\n",d);
215
216    /***
217     *** I'm not the one to blame of you screw your computer!
218     ***/
219    if(rwmode & ! force){
220        unsigned char warnbuf[4];
221        fprintf(stderr,"**WARNING**\n");
222        fprintf(stderr," - \tYou have chosen to WRITE to this eeprom.\n");
223        fprintf(stderr,"\tMake sure that this tiny chip is *NOT* vital to the\n");
224        fprintf(stderr,"\toperation of your computer as you can easily corrupt\n");
225        fprintf(stderr,"\tthe configuration memory of your SDRAM-memory-module,\n");
226        fprintf(stderr,"\tyour IBM ThinkPad or whatnot...! Fixing these errors can be\n");
227        fprintf(stderr,"\ta time-consuming and very costly process!\n\n");
228        fprintf(stderr,"Things to consider:\n");
229        fprintf(stderr," - \tYou can have more than one i2c-bus, check in /proc/bus/i2c\n");
230        fprintf(stderr,"\tand specify the correct one with -d\n");
231        fprintf(stderr,"\tright now you have chosen to use '%s'\n",dn);
232        fprintf(stderr," - \tA eeprom can occupy several i2c-addresses (one per page)\n");
233        fprintf(stderr,"\tso please make sure that there is no vital eeprom in your computer\n");
234        fprintf(stderr,"\tsitting at addresses between 0x%02x and 0x%02x\n",addr,addr+pages-1);
235
236        fprintf(stderr,"Enter 'yes' to continue:");
237        fflush(stderr);
238        if(!fgets(warnbuf,sizeof(warnbuf),stdin)){
239            fprintf(stderr,"\nCould not read confirmation from stdin!\n");
240            exit(1);
241        }
242        if(strncmp(warnbuf,"yes",3)){
243            fprintf(stderr,"\n** ABORTING WRITE! **, you did not answer 'yes'\n");
244            exit(1);
245        }
246    }
247
248    for(i=0;i<pages;i++){
249        unsigned char buf[BYTES_PER_PAGE];
250
251        if(rwmode){
252
253            if(f>=0){
254                j=read(f,buf,sizeof(buf));
255                if(j<0){
256                    fprintf(stderr,"Cannot read from file '%s'\n",fn);
257                    perror(fn);
258                    exit(1);
259                }
260                if(j!=sizeof(buf)){
261                    fprintf(stderr,"File '%s' is too small, padding eeprom with zeroes\n",fn);
262                    while(j<sizeof(buf))
263                        buf[j++]=0;
264                }
265            } else {
266                for(j=0;j<sizeof(buf);j++)
267                    buf[j]=0;
268            }
269            for(j=0;j<(BYTES_PER_PAGE/MAX_BYTES);j++)
270                if(eeprom_write(d,addr+i,j*MAX_BYTES,buf+(j*MAX_BYTES),MAX_BYTES)<0)
271                    exit(1);
272        } else {
273            for(j=0;j<(BYTES_PER_PAGE/MAX_BYTES);j++)
274                if(eeprom_read(d,addr+i,j*MAX_BYTES,buf+(j*MAX_BYTES),MAX_BYTES)<0)
275                    exit(1);
276        }
277
278
279        if(!rwmode && f>=0){
280            j=write(f,buf,sizeof(buf));
281            if(j!=sizeof(buf)){
282                fprintf(stderr,"Cannot write to file '%s'\n",fn);
283                perror(fn);
284                exit(1);
285            }
286        }
287
288    }
289
290    if(f>=0)
291        close(f);
292
293    close(d);
294
295    exit(0);
296
297}
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