Add a --bus-info option to media-ctl which opens the media device that has this bus info string. That makes it possible to open a specific media device without having to know the name of the media device.
Similar functionality has been implemented for v4l2-ctl and v4l2-compliance, and for the cec utilities. This allows scripts that no longer need to care about the name of a device node, instead they can find it based on a unique string. Also extend the -d option to support -d0 as a shorthand for /dev/media0 to make it consistent with the other utils. Signed-off-by: Hans Verkuil <hverkuil-ci...@xs4all.nl> --- diff --git a/utils/media-ctl/options.c b/utils/media-ctl/options.c index 16367857..0430b8bc 100644 --- a/utils/media-ctl/options.c +++ b/utils/media-ctl/options.c @@ -19,13 +19,18 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <ctype.h> +#include <dirent.h> +#include <fcntl.h> #include <getopt.h> #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <sys/ioctl.h> #include <unistd.h> #include <v4l2subdev.h> +#include <linux/media.h> #include <linux/videodev2.h> #include "options.h" @@ -42,7 +47,9 @@ static void usage(const char *argv0) unsigned int i; printf("%s [options]\n", argv0); + printf("-b, --bus-info name Use the media device with bus info equal to name\n"); printf("-d, --device dev Media device name (default: %s)\n", MEDIA_DEVNAME_DEFAULT); + printf(" If <dev> starts with a digit, then /dev/media<dev> is used.\n"); printf("-e, --entity name Print the device name associated with the given entity\n"); printf("-V, --set-v4l2 v4l2 Comma-separated list of formats to setup\n"); printf(" --get-v4l2 pad Print the active format on a given pad\n"); @@ -121,6 +128,7 @@ static void usage(const char *argv0) #define OPT_GET_DV 260 static struct option opts[] = { + {"bus-info", 1, 0, 'b'}, {"device", 1, 0, 'd'}, {"entity", 1, 0, 'e'}, {"set-format", 1, 0, 'f'}, @@ -161,6 +169,51 @@ static void list_known_mbus_formats(void) } } +static const char *find_bus_info(const char *bus_info) +{ + static char newdev[300]; + struct dirent *ep; + DIR *dp; + + dp = opendir("/dev"); + if (dp == NULL) + return NULL; + + while ((ep = readdir(dp))) { + const char *name = ep->d_name; + + if (!memcmp(name, "media", 5) && isdigit(name[5])) { + struct media_device_info mdi; + int ret; + int fd; + + snprintf(newdev, sizeof(newdev), "/dev/%s", name); + fd = open(newdev, O_RDWR); + if (fd < 0) + continue; + ret = ioctl(fd, MEDIA_IOC_DEVICE_INFO, &mdi); + close(fd); + if (!ret && !strcmp(bus_info, mdi.bus_info)) { + closedir(dp); + return newdev; + } + } + } + closedir(dp); + return NULL; +} + +static const char *make_devname(const char *device) +{ + static char newdev[300]; + + if (device[0] >= '0' && device[0] <= '9' && strlen(device) <= 3) { + snprintf(newdev, sizeof(newdev), "/dev/media%s", device); + return newdev; + } + return device; +} + int parse_cmdline(int argc, char **argv) { int opt; @@ -171,11 +224,20 @@ int parse_cmdline(int argc, char **argv) } /* parse options */ - while ((opt = getopt_long(argc, argv, "d:e:f:hil:prvV:", + while ((opt = getopt_long(argc, argv, "b:d:e:f:hil:prvV:", opts, NULL)) != -1) { switch (opt) { + case 'b': + media_opts.devname = find_bus_info(optarg); + if (!media_opts.devname) { + fprintf(stderr, "Error: no media device with bus info '%s' found\n", + optarg); + return 1; + } + break; + case 'd': - media_opts.devname = optarg; + media_opts.devname = make_devname(optarg); break; case 'e':
