Adding Jean Delvare who maintains i2c-tools to CC... On Thu, Jun 05, 2014 at 10:17:33AM +0200, Michal Minář wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hello, > > we've got following request (viz [1]): > > i2cdetect requires the i2c-dev module be loaded so the appropriate > /dev entries are created. This is not done automatically, so when > i2cdetect is initially run it gives the false impression that no > buses/devices exist: > > # i2cdetect -l > # modprobe i2c-dev > # i2cdetect -l > i2c-0 i2c i915 gmbus ssc I2C adapter > i2c-1 i2c i915 gmbus vga I2C adapter > i2c-2 i2c i915 gmbus panel I2C adapter > i2c-3 i2c i915 gmbus dpc I2C adapter > i2c-4 i2c i915 gmbus dpb I2C adapter > i2c-5 i2c i915 gmbus dpd I2C adapter > i2c-6 i2c DPDDC-C I2C adapter > i2c-7 i2c DPDDC-D I2C adapter > > > Attached is a patch that autoloads i2c-dev module when neccessary. If > you like it and have commit rights, push it please instead of me. If > you don't like it, don't hold back and tell me. > > Best regards, > Michal Minar > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=913203 > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1 > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iQEcBAEBAgAGBQJTkCedAAoJEPezUylxRFUDExAIAJzpGhv0O0U4zFCkzz9wH1cM > mJOzW6Pu/Xnxk/x9e5f5RVG3BIrieJueRbzU/nh+KHqWbvEV/8DOtQ6KVV3c4Sau > Deocg/QqdpMH1UasVIio2iUyuBJS/RvhclJOzo05cDhLfyo5bSp7ixLBwwcjlY4c > UeXcTq7OPID5B4bpZzs2R7T2M81FG3wdI8GcqTNthQahLnCa0XbxEbyGZn2XaiVD > 51AeADzmD5OTCPfQFmYq87MW/S101O+GEJJwXb/DngHh2mIVnur0JiDnABdB+Pl4 > ysgqooMOMol2blcUQmkwwLzkJ3ArE3MGvjGVtqFBOsI5VSpWsapGa6TdFeYm0UY= > =4tFG > -----END PGP SIGNATURE-----
> Index: i2c-tools-3.1.0/tools/i2cbusses.c
> ===================================================================
> --- i2c-tools-3.1.0.orig/tools/i2cbusses.c
> +++ i2c-tools-3.1.0/tools/i2cbusses.c
> @@ -37,9 +37,15 @@
> #include <dirent.h>
> #include <fcntl.h>
> #include <errno.h>
> +#ifdef USE_LIBKMOD
> + #include <libkmod.h>
> +#endif
> #include "i2cbusses.h"
> #include <linux/i2c-dev.h>
>
> +#define BUFLEN 512
> +#define I2C_DEV_MOD_NAME "i2c_dev"
> +
> enum adt { adt_dummy, adt_isa, adt_i2c, adt_smbus, adt_unknown };
>
> struct adap_type {
> @@ -60,6 +66,70 @@ static struct adap_type adap_types[5] =
> .algo = "N/A", },
> };
>
> +/**
> + * Try to load i2c_dev kernel mode. Do nothing, if module is already loaded.
> + * Returns 1 on success, 0 otherwise.
> + */
> +static int try_load_i2c_dev_mod(void) {
> + int err = 0, loaded = 0;
> + char errbuf[BUFLEN] = { 0 };
> +#ifdef USE_LIBKMOD
> + int flags = 0;
> + struct kmod_ctx *ctx;
> + struct kmod_list *l, *list = NULL;
> +
> + ctx = kmod_new(NULL, NULL);
> + if (!ctx) {
> + snprintf(errbuf, BUFLEN, "kmod_new() failed!");
> + goto done;
> + }
> + if (kmod_module_new_from_lookup(ctx, I2C_DEV_MOD_NAME, &list) < 0 ||
> list == NULL) {
> + snprintf(errbuf, BUFLEN, I2C_DEV_MOD_NAME " module lookup
> failed");
> + goto ctx_unref;
> + }
> +
> + flags |= KMOD_PROBE_APPLY_BLACKLIST_ALIAS_ONLY;
> + kmod_list_foreach(l, list) {
> + struct kmod_module *mod = kmod_module_get_module(l);
> + err = kmod_module_probe_insert_module(mod, flags, NULL, NULL,
> NULL, NULL);
> + if (err == -ENOENT) {
> + snprintf(errbuf, BUFLEN,
> + "unknown symbol in module \"%s\", or
> unknown parameter (see dmesg)",
> + kmod_module_get_name(mod));
> + } else if (err < 0) {
> + snprintf(errbuf, BUFLEN, "(module %s): %s",
> + kmod_module_get_name(mod),
> strerror(-err));
> + } else {
> + kmod_module_unref(mod);
> + ++loaded;
> + break;
> + }
> + kmod_module_unref(mod);
> + }
> +
> +list_unref:
> + kmod_module_unref_list(list);
> +ctx_unref:
> + kmod_unref(ctx);
> +#else
> + err = system("modprobe " I2C_DEV_MOD_NAME);
> + if (err < 0) {
> + snprintf(errbuf, BUFLEN, "failed to execute modprobe command");
> + } else if (err > 0) {
> + snprintf(errbuf, BUFLEN, "modprobe command exited with code %d",
> + WEXITSTATUS(err));
> + } else {
> + ++loaded;
> + goto done;
> + }
> +#endif
> + if (errbuf[0])
> + fprintf(stderr, "Failed to load required " I2C_DEV_MOD_NAME
> + " kernel module: %s\n", errbuf);
> +done:
> + return loaded;
> +}
> +
> static enum adt i2c_get_funcs(int i2cbus)
> {
> unsigned long funcs;
> @@ -206,8 +276,12 @@ struct i2c_adap *gather_i2c_busses(void)
> i2c-dev and what we really care about are the i2c-dev numbers.
> Unfortunately the names are harder to get in i2c-dev */
> strcat(sysfs, "/class/i2c-dev");
> - if(!(dir = opendir(sysfs)))
> - goto done;
> + if(!(dir = opendir(sysfs))) {
> + if (!try_load_i2c_dev_mod())
> + goto done;
> + if ((!(dir = opendir(sysfs))))
> + goto done;
> + }
> /* go through the busses */
> while ((de = readdir(dir)) != NULL) {
> if (!strcmp(de->d_name, "."))
> Index: i2c-tools-3.1.0/tools/Module.mk
> ===================================================================
> --- i2c-tools-3.1.0.orig/tools/Module.mk
> +++ i2c-tools-3.1.0/tools/Module.mk
> @@ -15,6 +15,11 @@ TOOLS_CFLAGS := -Wstrict-prototypes -Wsh
>
> TOOLS_TARGETS := i2cdetect i2cdump i2cset i2cget
>
> +ifeq ($(shell pkg-config --exists libkmod && echo 1), 1)
> + TOOLS_CFLAGS += $(shell pkg-config --cflags libkmod) -DUSE_LIBKMOD
> + LDFLAGS += $(shell pkg-config --libs libkmod)
> +endif
> +
> #
> # Programs
> #
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