Re: [PATCH 2/2] iio: generic_buffer: Add --device-num option

[Jonathan Cameron <jic23@kernel.org>]

On 20/05/16 16:45, Crestez Dan Leonard wrote:
> This makes it possible to distinguish between iio devices with the same
> name.
> 
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
happy with this and will pickup once the first patch is sorted.

Jonathan
> ---
>  tools/iio/generic_buffer.c | 53 ++++++++++++++++++++++++++++++++++------------
>  1 file changed, 40 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/iio/generic_buffer.c b/tools/iio/generic_buffer.c
> index e7bf477..f805ef9 100644
> --- a/tools/iio/generic_buffer.c
> +++ b/tools/iio/generic_buffer.c
> @@ -251,7 +251,9 @@ void print_usage(void)
>  		"  -e         Disable wait for event (new data)\n"
>  		"  -g         Use trigger-less mode\n"
>  		"  -l <n>     Set buffer length to n samples\n"
> -		"  -n <name>  Set device name (mandatory)\n"
> +		"  --device-name -n <name>\n"
> +		"  --device-num -N <num>\n"
> +		"        Set device by name or number"
>  		"  -t <name>  Set trigger name\n"
>  		"  -w <n>     Set delay between reads in us (event-less mode)\n");
>  }
> @@ -319,6 +321,12 @@ void register_cleanup(void)
>  	}
>  }
>  
> +static const struct option longopts[] = {
> +	{ "device-name",	1, 0, 'n' },
> +	{ "device-num",		1, 0, 'N' },
> +	{ },
> +};
> +
>  int main(int argc, char **argv)
>  {
>  	unsigned long num_loops = 2;
> @@ -333,7 +341,7 @@ int main(int argc, char **argv)
>  
>  	char *data;
>  	ssize_t read_size;
> -	int dev_num, trig_num;
> +	int dev_num = -1, trig_num;
>  	char *buffer_access;
>  	int scan_size;
>  	int noevents = 0;
> @@ -344,7 +352,7 @@ int main(int argc, char **argv)
>  
>  	register_cleanup();
>  
> -	while ((c = getopt(argc, argv, "ac:egl:n:t:w:")) != -1) {
> +	while ((c = getopt_long(argc, argv, "ac:egl:n:N:t:w:", longopts, NULL)) != -1) {
>  		switch (c) {
>  		case 'a':
>  			autochannels = AUTOCHANNELS_ENABLED;
> @@ -372,6 +380,12 @@ int main(int argc, char **argv)
>  		case 'n':
>  			device_name = optarg;
>  			break;
> +		case 'N':
> +			errno = 0;
> +			dev_num = strtoul(optarg, &dummy, 10);
> +			if (errno)
> +				return -errno;
> +			break;
>  		case 't':
>  			trigger_name = optarg;
>  			break;
> @@ -387,24 +401,37 @@ int main(int argc, char **argv)
>  		}
>  	}
>  
> -	if (!device_name) {
> -		fprintf(stderr, "Device name not set\n");
> +	/* Find the device requested */
> +	if (dev_num < 0 && !device_name) {
> +		fprintf(stderr, "Device not set\n");
>  		print_usage();
>  		return -1;
> +	} else if (dev_num >= 0 && device_name) {
> +		fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
> +		print_usage();
> +		return -1;
> +	} else if (dev_num < 0) {
> +		dev_num = find_type_by_name(device_name, "iio:device");
> +		if (dev_num < 0) {
> +			fprintf(stderr, "Failed to find the %s\n", device_name);
> +			return dev_num;
> +		}
>  	}
> -
> -	/* Find the device requested */
> -	dev_num = find_type_by_name(device_name, "iio:device");
> -	if (dev_num < 0) {
> -		fprintf(stderr, "Failed to find the %s\n", device_name);
> -		return dev_num;
> -	}
> -
>  	printf("iio device number being used is %d\n", dev_num);
>  
>  	ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
>  	if (ret < 0)
>  		return -ENOMEM;
> +	if (!device_name) {
> +		device_name = malloc(IIO_MAX_NAME_LENGTH);
> +		if (!device_name)
> +			return -ENOMEM;
> +		ret = read_sysfs_string("name", dev_dir_name, device_name);
> +		if (ret < 0) {
> +			fprintf(stderr, "Failed to read name of device %d\n", dev_num);
> +			return ret;
> +		}
> +	}
>  
>  	if (!notrigger) {
>  		if (!trigger_name) {
>