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259 lines
6.6 KiB
259 lines
6.6 KiB
/*
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i2cbusses: Print the installed i2c busses for both 2.4 and 2.6 kernels.
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Part of user-space programs to access for I2C
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devices.
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Copyright (c) 1999-2003 Frodo Looijaard <frodol@dds.nl> and
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Mark D. Studebaker <mdsxyz123@yahoo.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <string.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <limits.h>
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#include <dirent.h>
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#include <fcntl.h>
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#include <errno.h>
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#include "i2cbusses.h"
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#include "i2c-dev.h"
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enum adt { adt_dummy, adt_isa, adt_i2c, adt_smbus, adt_unknown };
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struct adap_type {
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const char *funcs;
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const char* algo;
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};
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static struct adap_type adap_types[5] = {
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{ .funcs = "dummy",
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.algo = "Dummy bus", },
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{ .funcs = "isa",
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.algo = "ISA bus", },
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{ .funcs = "i2c",
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.algo = "I2C adapter", },
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{ .funcs = "smbus",
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.algo = "SMBus adapter", },
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{ .funcs = "unknown",
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.algo = "N/A", },
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};
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static enum adt i2c_get_funcs(int i2cbus)
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{
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unsigned long funcs;
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int file;
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char filename[20];
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enum adt ret;
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file = open_i2c_dev(i2cbus, filename, 1);
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if (file < 0)
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return adt_unknown;
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if (ioctl(file, I2C_FUNCS, &funcs) < 0)
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ret = adt_unknown;
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else if (funcs & I2C_FUNC_I2C)
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ret = adt_i2c;
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else if (funcs & (I2C_FUNC_SMBUS_BYTE |
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I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_WORD_DATA))
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ret = adt_smbus;
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else
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ret = adt_dummy;
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close(file);
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return ret;
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}
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/*
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this just prints out the installed i2c busses in a consistent format, whether
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on a 2.4 kernel using /proc or a 2.6 kernel using /sys.
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If procfmt == 1, print out exactly /proc/bus/i2c format on stdout.
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This allows this to be used in a program to emulate /proc/bus/i2c on a
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sysfs system.
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*/
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void print_i2c_busses(int procfmt)
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{
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FILE *fptr;
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char s[100];
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struct dirent *de, *dde;
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DIR *dir, *ddir;
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FILE *f;
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char *border;
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char dev[NAME_MAX], fstype[NAME_MAX], sysfs[NAME_MAX], n[NAME_MAX];
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int foundsysfs = 0;
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int count=0;
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/* look in /proc/bus/i2c */
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if((fptr = fopen("/proc/bus/i2c", "r"))) {
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while(fgets(s, 100, fptr)) {
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if(count++ == 0 && !procfmt)
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fprintf(stderr," Installed I2C busses:\n");
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if(procfmt)
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printf("%s", s);
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else
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fprintf(stderr, " %s", s);
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}
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fclose(fptr);
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goto done;
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}
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/* look in sysfs */
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/* First figure out where sysfs was mounted */
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if ((f = fopen("/proc/mounts", "r")) == NULL) {
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goto done;
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}
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while (fgets(n, NAME_MAX, f)) {
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sscanf(n, "%[^ ] %[^ ] %[^ ] %*s\n", dev, sysfs, fstype);
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if (strcasecmp(fstype, "sysfs") == 0) {
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foundsysfs++;
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break;
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}
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}
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fclose(f);
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if (! foundsysfs) {
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goto done;
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}
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/* Bus numbers in i2c-adapter don't necessarily match those in
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i2c-dev and what we really care about are the i2c-dev numbers.
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Unfortunately the names are harder to get in i2c-dev */
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strcat(sysfs, "/class/i2c-dev");
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if(!(dir = opendir(sysfs)))
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goto done;
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/* go through the busses */
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while ((de = readdir(dir)) != NULL) {
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if (!strcmp(de->d_name, "."))
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continue;
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if (!strcmp(de->d_name, ".."))
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continue;
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/* this should work for kernels 2.6.5 or higher and */
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/* is preferred because is unambiguous */
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sprintf(n, "%s/%s/name", sysfs, de->d_name);
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f = fopen(n, "r");
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/* this seems to work for ISA */
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if(f == NULL) {
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sprintf(n, "%s/%s/device/name", sysfs, de->d_name);
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f = fopen(n, "r");
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}
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/* non-ISA is much harder */
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/* and this won't find the correct bus name if a driver
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has more than one bus */
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if(f == NULL) {
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sprintf(n, "%s/%s/device", sysfs, de->d_name);
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if(!(ddir = opendir(n)))
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continue;
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while ((dde = readdir(ddir)) != NULL) {
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if (!strcmp(dde->d_name, "."))
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continue;
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if (!strcmp(dde->d_name, ".."))
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continue;
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if ((!strncmp(dde->d_name, "i2c-", 4))) {
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sprintf(n, "%s/%s/device/%s/name",
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sysfs, de->d_name, dde->d_name);
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if((f = fopen(n, "r")))
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goto found;
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}
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}
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}
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found:
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if (f != NULL) {
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int i2cbus;
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enum adt type;
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char x[120];
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char *px;
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px = fgets(x, 120, f);
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fclose(f);
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if (!px) {
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fprintf(stderr, "%s: read error\n", n);
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continue;
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}
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if((border = index(x, '\n')) != NULL)
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*border = 0;
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if(count++ == 0 && !procfmt)
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fprintf(stderr," Installed I2C busses:\n");
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/* match 2.4 /proc/bus/i2c format as closely as possible */
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if(!strncmp(x, "ISA ", 4)) {
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type = adt_isa;
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} else if(!sscanf(de->d_name, "i2c-%d", &i2cbus)) {
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type = adt_dummy;
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} else {
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/* Attempt to probe for adapter capabilities */
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type = i2c_get_funcs(i2cbus);
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}
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if (procfmt)
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printf("%s\t%-10s\t%-32s\t%s\n", de->d_name,
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adap_types[type].funcs, x, adap_types[type].algo);
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else
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fprintf(stderr, " %s\t%-10s\t%s\n", de->d_name,
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adap_types[type].funcs, x);
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}
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}
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closedir(dir);
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done:
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if(count == 0 && !procfmt)
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fprintf(stderr,"Error: No I2C busses found!\n"
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"Be sure you have done 'modprobe i2c-dev'\n"
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"and also modprobed your i2c bus drivers\n");
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}
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int open_i2c_dev(const int i2cbus, char *filename, const int quiet)
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{
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int file;
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sprintf(filename, "/dev/i2c/%d", i2cbus);
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file = open(filename, O_RDWR);
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if (file < 0 && errno == ENOENT) {
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sprintf(filename, "/dev/i2c-%d", i2cbus);
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file = open(filename, O_RDWR);
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}
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if (file < 0 && !quiet) {
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if (errno == ENOENT) {
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fprintf(stderr, "Error: Could not open file "
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"`/dev/i2c-%d' or `/dev/i2c/%d': %s\n",
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i2cbus, i2cbus, strerror(ENOENT));
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} else {
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fprintf(stderr, "Error: Could not open file "
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"`%s': %s\n", filename, strerror(errno));
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if (errno == EACCES)
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fprintf(stderr, "Run as root?\n");
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}
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}
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return file;
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}
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int set_slave_addr(int file, int address, int force)
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{
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/* With force, let the user read from/write to the registers
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even when a driver is also running */
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if (ioctl(file, force ? I2C_SLAVE_FORCE : I2C_SLAVE, address) < 0) {
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fprintf(stderr,
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"Error: Could not set address to 0x%02x: %s\n",
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address, strerror(errno));
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return -errno;
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}
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return 0;
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}
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