spi: spidev_test: Sorted the options into logical groups

In order to increase usability, the command line options are sorted into
logical groups. In addition, the usage string was sorted alphabetically,
and the missing parameters '8','i' and 'o' were added. Furthermore, the
option descriptions were moved further to the right, in order to allow
for longer option names.
Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com>
Link: https://lore.kernel.org/r/20230530141641.1155691-5-boerge.struempfel@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

tools/spi/spidev_test.c

@@ -172,28 +172,34 @@ static void transfer(int fd, uint8_t const *tx, uint8_t const *rx, size_t len)
 
 static void print_usage(const char *prog)
 {
-	printf("Usage: %s [-DsbdlHOLC3vpNR24SI]\n", prog);
-	puts("  -D --device   device to use (default /dev/spidev1.1)\n"
-	     "  -s --speed    max speed (Hz)\n"
-	     "  -d --delay    delay (usec)\n"
-	     "  -b --bpw      bits per word\n"
-	     "  -i --input    input data from a file (e.g. \"test.bin\")\n"
-	     "  -o --output   output data to a file (e.g. \"results.bin\")\n"
-	     "  -l --loop     loopback\n"
-	     "  -H --cpha     clock phase\n"
-	     "  -O --cpol     clock polarity\n"
-	     "  -L --lsb      least significant bit first\n"
-	     "  -C --cs-high  chip select active high\n"
-	     "  -3 --3wire    SI/SO signals shared\n"
-	     "  -v --verbose  Verbose (show tx buffer)\n"
-	     "  -p            Send data (e.g. \"1234\\xde\\xad\")\n"
-	     "  -N --no-cs    no chip select\n"
-	     "  -R --ready    slave pulls low to pause\n"
-	     "  -2 --dual     dual transfer\n"
-	     "  -4 --quad     quad transfer\n"
-	     "  -8 --octal    octal transfer\n"
-	     "  -S --size     transfer size\n"
-	     "  -I --iter     iterations\n");
+	printf("Usage: %s [-2348CDHILNORSbdilopsv]\n", prog);
+	puts("general device settings:\n"
+		 "  -D --device         device to use (default /dev/spidev1.1)\n"
+		 "  -s --speed          max speed (Hz)\n"
+		 "  -d --delay          delay (usec)\n"
+		 "  -l --loop           loopback\n"
+		 "spi mode:\n"
+		 "  -H --cpha           clock phase\n"
+		 "  -O --cpol           clock polarity\n"
+		 "number of wires for transmission:\n"
+		 "  -2 --dual           dual transfer\n"
+		 "  -4 --quad           quad transfer\n"
+		 "  -8 --octal          octal transfer\n"
+		 "  -3 --3wire          SI/SO signals shared\n"
+		 "data:\n"
+		 "  -i --input          input data from a file (e.g. \"test.bin\")\n"
+		 "  -o --output         output data to a file (e.g. \"results.bin\")\n"
+		 "  -p                  Send data (e.g. \"1234\\xde\\xad\")\n"
+		 "  -S --size           transfer size\n"
+		 "  -I --iter           iterations\n"
+		 "additional parameters:\n"
+		 "  -b --bpw            bits per word\n"
+		 "  -L --lsb            least significant bit first\n"
+		 "  -C --cs-high        chip select active high\n"
+		 "  -N --no-cs          no chip select\n"
+		 "  -R --ready          slave pulls low to pause\n"
+		 "misc:\n"
+		 "  -v --verbose        Verbose (show tx buffer)\n");
 	exit(1);
 }
 
@@ -201,26 +207,26 @@ static void parse_opts(int argc, char *argv[])
 {
 	while (1) {
 		static const struct option lopts[] = {
-			{ "device",  1, 0, 'D' },
-			{ "speed",   1, 0, 's' },
-			{ "delay",   1, 0, 'd' },
-			{ "bpw",     1, 0, 'b' },
-			{ "input",   1, 0, 'i' },
-			{ "output",  1, 0, 'o' },
-			{ "loop",    0, 0, 'l' },
-			{ "cpha",    0, 0, 'H' },
-			{ "cpol",    0, 0, 'O' },
-			{ "lsb",     0, 0, 'L' },
-			{ "cs-high", 0, 0, 'C' },
-			{ "3wire",   0, 0, '3' },
-			{ "no-cs",   0, 0, 'N' },
-			{ "ready",   0, 0, 'R' },
-			{ "dual",    0, 0, '2' },
-			{ "verbose", 0, 0, 'v' },
-			{ "quad",    0, 0, '4' },
-			{ "octal",   0, 0, '8' },
-			{ "size",    1, 0, 'S' },
-			{ "iter",    1, 0, 'I' },
+			{ "device",        1, 0, 'D' },
+			{ "speed",         1, 0, 's' },
+			{ "delay",         1, 0, 'd' },
+			{ "loop",          0, 0, 'l' },
+			{ "cpha",          0, 0, 'H' },
+			{ "cpol",          0, 0, 'O' },
+			{ "dual",          0, 0, '2' },
+			{ "quad",          0, 0, '4' },
+			{ "octal",         0, 0, '8' },
+			{ "3wire",         0, 0, '3' },
+			{ "input",         1, 0, 'i' },
+			{ "output",        1, 0, 'o' },
+			{ "size",          1, 0, 'S' },
+			{ "iter",          1, 0, 'I' },
+			{ "bpw",           1, 0, 'b' },
+			{ "lsb",           0, 0, 'L' },
+			{ "cs-high",       0, 0, 'C' },
+			{ "no-cs",         0, 0, 'N' },
+			{ "ready",         0, 0, 'R' },
+			{ "verbose",       0, 0, 'v' },
 			{ NULL, 0, 0, 0 },
 		};
 		int c;