cpupower: use man(1) when calling "cpupower help subcommand"

Instead of printing something non-formatted to stdout, call
man(1) to show the man page for the proper subcommand.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

8 files changed, 72 insertions, 214 deletions

diff --git a/tools/power/cpupower/utils/builtin.h b/tools/power/cpupower/utils/builtin.h
index c870ffba5219..c10496fbe3c6 100644
--- a/tools/power/cpupower/utils/builtin.h
+++ b/tools/power/cpupower/utils/builtin.h
@@ -8,11 +8,4 @@ extern int cmd_freq_info(int argc, const char **argv);
 extern int cmd_idle_info(int argc, const char **argv);
 extern int cmd_monitor(int argc, const char **argv);
 
-extern void set_help(void);
-extern void info_help(void);
-extern void freq_set_help(void);
-extern void freq_info_help(void);
-extern void idle_info_help(void);
-extern void monitor_help(void);
-
 #endif
diff --git a/tools/power/cpupower/utils/cpufreq-info.c b/tools/power/cpupower/utils/cpufreq-info.c
index 5a1d25f056b3..28953c9a7bd5 100644
--- a/tools/power/cpupower/utils/cpufreq-info.c
+++ b/tools/power/cpupower/utils/cpufreq-info.c
@@ -510,37 +510,6 @@ static int get_latency(unsigned int cpu, unsigned int human)
         return 0;
 }
 
-void freq_info_help(void)
-{
-        printf(_("Usage: cpupower freqinfo [options]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -e, --debug          Prints out debug information [default]\n"));
-        printf(_("  -f, --freq           Get frequency the CPU currently runs at, according\n"
-               "                       to the cpufreq core *\n"));
-        printf(_("  -w, --hwfreq         Get frequency the CPU currently runs at, by reading\n"
-               "                       it from hardware (only available to root) *\n"));
-        printf(_("  -l, --hwlimits       Determine the minimum and maximum CPU frequency allowed *\n"));
-        printf(_("  -d, --driver         Determines the used cpufreq kernel driver *\n"));
-        printf(_("  -p, --policy         Gets the currently used cpufreq policy *\n"));
-        printf(_("  -g, --governors      Determines available cpufreq governors *\n"));
-        printf(_("  -r, --related-cpus   Determines which CPUs run at the same hardware frequency *\n"));
-        printf(_("  -a, --affected-cpus  Determines which CPUs need to have their frequency\n"
-                        "                       coordinated by software *\n"));
-        printf(_("  -s, --stats          Shows cpufreq statistics if available\n"));
-        printf(_("  -y, --latency        Determines the maximum latency on CPU frequency changes *\n"));
-        printf(_("  -b, --boost          Checks for turbo or boost modes  *\n"));
-        printf(_("  -o, --proc           Prints out information like provided by the /proc/cpufreq\n"
-               "                       interface in 2.4. and early 2.6. kernels\n"));
-        printf(_("  -m, --human          human-readable output for the -f, -w, -s and -y parameters\n"));
-        printf(_("  -h, --help           Prints out this screen\n"));
-
-        printf("\n");
-        printf(_("If no argument is given, full output about\n"
-               "cpufreq is printed which is useful e.g. for reporting bugs.\n\n"));
-        printf(_("By default info of CPU 0 is shown which can be overridden\n"
-                 "with the cpupower --cpu main command option.\n"));
-}
-
 static struct option info_opts[] = {
         { .name = "debug",      .has_arg = no_argument,         .flag = NULL,   .val = 'e'},
         { .name = "boost",      .has_arg = no_argument,         .flag = NULL,   .val = 'b'},
@@ -556,7 +525,6 @@ static struct option info_opts[] = {
         { .name = "latency",    .has_arg = no_argument,         .flag = NULL,   .val = 'y'},
         { .name = "proc",       .has_arg = no_argument,         .flag = NULL,   .val = 'o'},
         { .name = "human",      .has_arg = no_argument,         .flag = NULL,   .val = 'm'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { },
 };
 
@@ -570,16 +538,12 @@ int cmd_freq_info(int argc, char **argv)
         int output_param = 0;
 
         do {
-                ret = getopt_long(argc, argv, "hoefwldpgrasmyb", info_opts, NULL);
+                ret = getopt_long(argc, argv, "oefwldpgrasmyb", info_opts, NULL);
                 switch (ret) {
                 case '?':
                         output_param = '?';
                         cont = 0;
                         break;
-                case 'h':
-                        output_param = 'h';
-                        cont = 0;
-                        break;
                 case -1:
                         cont = 0;
                         break;
@@ -642,11 +606,7 @@ int cmd_freq_info(int argc, char **argv)
                 return -EINVAL;
         case '?':
                 printf(_("invalid or unknown argument\n"));
-                freq_info_help();
                 return -EINVAL;
-        case 'h':
-                freq_info_help();
-                return EXIT_SUCCESS;
         case 'o':
                 proc_cpufreq_output();
                 return EXIT_SUCCESS;
diff --git a/tools/power/cpupower/utils/cpufreq-set.c b/tools/power/cpupower/utils/cpufreq-set.c
index 5f783622bf31..dd1539eb8c63 100644
--- a/tools/power/cpupower/utils/cpufreq-set.c
+++ b/tools/power/cpupower/utils/cpufreq-set.c
@@ -20,34 +20,11 @@
 
 #define NORM_FREQ_LEN 32
 
-void freq_set_help(void)
-{
-        printf(_("Usage: cpupower frequency-set [options]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -d FREQ, --min FREQ      new minimum CPU frequency the governor may select\n"));
-        printf(_("  -u FREQ, --max FREQ      new maximum CPU frequency the governor may select\n"));
-        printf(_("  -g GOV, --governor GOV   new cpufreq governor\n"));
-        printf(_("  -f FREQ, --freq FREQ     specific frequency to be set. Requires userspace\n"
-               "                           governor to be available and loaded\n"));
-        printf(_("  -r, --related            Switches all hardware-related CPUs\n"));
-        printf(_("  -h, --help               Prints out this screen\n"));
-        printf("\n");
-        printf(_("Notes:\n"
-               "1. Omitting the -c or --cpu argument is equivalent to setting it to \"all\"\n"));
-        printf(_("2. The -f FREQ, --freq FREQ parameter cannot be combined with any other parameter\n"
-               "   except the -c CPU, --cpu CPU parameter\n"
-               "3. FREQuencies can be passed in Hz, kHz (default), MHz, GHz, or THz\n"
-               "   by postfixing the value with the wanted unit name, without any space\n"
-               "   (FREQuency in kHz =^ Hz * 0.001 =^ MHz * 1000 =^ GHz * 1000000).\n"));
-
-}
-
 static struct option set_opts[] = {
         { .name = "min",        .has_arg = required_argument,   .flag = NULL,   .val = 'd'},
         { .name = "max",        .has_arg = required_argument,   .flag = NULL,   .val = 'u'},
         { .name = "governor",   .has_arg = required_argument,   .flag = NULL,   .val = 'g'},
         { .name = "freq",       .has_arg = required_argument,   .flag = NULL,   .val = 'f'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { .name = "related",    .has_arg = no_argument,         .flag = NULL,   .val='r'},
         { },
 };
@@ -80,7 +57,6 @@ const struct freq_units def_units[] = {
 static void print_unknown_arg(void)
 {
         printf(_("invalid or unknown argument\n"));
-        freq_set_help();
 }
 
 static unsigned long string_to_frequency(const char *str)
@@ -231,14 +207,11 @@ int cmd_freq_set(int argc, char **argv)
 
         /* parameter parsing */
         do {
-                ret = getopt_long(argc, argv, "d:u:g:f:hr", set_opts, NULL);
+                ret = getopt_long(argc, argv, "d:u:g:f:r", set_opts, NULL);
                 switch (ret) {
                 case '?':
                         print_unknown_arg();
                         return -EINVAL;
-                case 'h':
-                        freq_set_help();
-                        return 0;
                 case -1:
                         cont = 0;
                         break;
diff --git a/tools/power/cpupower/utils/cpuidle-info.c b/tools/power/cpupower/utils/cpuidle-info.c
index 70da3574f1e9..b028267c1376 100644
--- a/tools/power/cpupower/utils/cpuidle-info.c
+++ b/tools/power/cpupower/utils/cpuidle-info.c
@@ -139,30 +139,14 @@ static void proc_cpuidle_cpu_output(unsigned int cpu)
         }
 }
 
-/* --freq / -f */
-
-void idle_info_help(void)
-{
-        printf(_ ("Usage: cpupower idleinfo [options]\n"));
-        printf(_ ("Options:\n"));
-        printf(_ ("  -s, --silent         Only show general C-state information\n"));
-        printf(_ ("  -o, --proc           Prints out information like provided by the /proc/acpi/processor/*/power\n"
-               "                       interface in older kernels\n"));
-        printf(_ ("  -h, --help           Prints out this screen\n"));
-
-        printf("\n");
-}
-
 static struct option info_opts[] = {
         { .name = "silent",     .has_arg = no_argument, .flag = NULL,   .val = 's'},
         { .name = "proc",       .has_arg = no_argument, .flag = NULL,   .val = 'o'},
-        { .name = "help",       .has_arg = no_argument, .flag = NULL,   .val = 'h'},
         { },
 };
 
 static inline void cpuidle_exit(int fail)
 {
-        idle_info_help();
         exit(EXIT_FAILURE);
 }
 
@@ -174,7 +158,7 @@ int cmd_idle_info(int argc, char **argv)
         unsigned int cpu = 0;
 
         do {
-                ret = getopt_long(argc, argv, "hos", info_opts, NULL);
+                ret = getopt_long(argc, argv, "os", info_opts, NULL);
                 if (ret == -1)
                         break;
                 switch (ret) {
@@ -182,10 +166,6 @@ int cmd_idle_info(int argc, char **argv)
                         output_param = '?';
                         cont = 0;
                         break;
-                case 'h':
-                        output_param = 'h';
-                        cont = 0;
-                        break;
                 case 's':
                         verbose = 0;
                         break;
@@ -211,8 +191,6 @@ int cmd_idle_info(int argc, char **argv)
         case '?':
                 printf(_("invalid or unknown argument\n"));
                 cpuidle_exit(EXIT_FAILURE);
-        case 'h':
-                cpuidle_exit(EXIT_SUCCESS);
         }
 
         /* Default is: show output of CPU 0 only */
diff --git a/tools/power/cpupower/utils/cpupower-info.c b/tools/power/cpupower/utils/cpupower-info.c
index 85253cb7600e..3f68632c28c7 100644
--- a/tools/power/cpupower/utils/cpupower-info.c
+++ b/tools/power/cpupower/utils/cpupower-info.c
@@ -16,31 +16,16 @@
 #include "helpers/helpers.h"
 #include "helpers/sysfs.h"
 
-void info_help(void)
-{
-        printf(_("Usage: cpupower info [ -b ] [ -m ] [ -s ]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -b, --perf-bias    Gets CPU's power vs performance policy on some\n"
-               "                           Intel models [0-15], see manpage for details\n"));
-        printf(_("  -m, --sched-mc     Gets the kernel's multi core scheduler policy.\n"));
-        printf(_("  -s, --sched-smt    Gets the kernel's thread sibling scheduler policy.\n"));
-        printf(_("  -h, --help               Prints out this screen\n"));
-        printf(_("\nPassing no option will show all info, by default only on core 0\n"));
-        printf("\n");
-}
-
 static struct option set_opts[] = {
         { .name = "perf-bias",  .has_arg = optional_argument,   .flag = NULL,   .val = 'b'},
         { .name = "sched-mc",   .has_arg = optional_argument,   .flag = NULL,   .val = 'm'},
         { .name = "sched-smt",  .has_arg = optional_argument,   .flag = NULL,   .val = 's'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { },
 };
 
 static void print_wrong_arg_exit(void)
 {
         printf(_("invalid or unknown argument\n"));
-        info_help();
         exit(EXIT_FAILURE);
 }
 
@@ -64,11 +49,8 @@ int cmd_info(int argc, char **argv)
         textdomain(PACKAGE);
 
         /* parameter parsing */
-        while ((ret = getopt_long(argc, argv, "msbh", set_opts, NULL)) != -1) {
+        while ((ret = getopt_long(argc, argv, "msb", set_opts, NULL)) != -1) {
                 switch (ret) {
-                case 'h':
-                        info_help();
-                        return 0;
                 case 'b':
                         if (params.perf_bias)
                                 print_wrong_arg_exit();
diff --git a/tools/power/cpupower/utils/cpupower-set.c b/tools/power/cpupower/utils/cpupower-set.c
index bc1b391e46f0..dc4de3762111 100644
--- a/tools/power/cpupower/utils/cpupower-set.c
+++ b/tools/power/cpupower/utils/cpupower-set.c
@@ -17,30 +17,16 @@
 #include "helpers/sysfs.h"
 #include "helpers/bitmask.h"
 
-void set_help(void)
-{
-        printf(_("Usage: cpupower set [ -b val ] [ -m val ] [ -s val ]\n"));
-        printf(_("Options:\n"));
-        printf(_("  -b, --perf-bias [VAL]    Sets CPU's power vs performance policy on some\n"
-               "                           Intel models [0-15], see manpage for details\n"));
-        printf(_("  -m, --sched-mc  [VAL]    Sets the kernel's multi core scheduler policy.\n"));
-        printf(_("  -s, --sched-smt [VAL]    Sets the kernel's thread sibling scheduler policy.\n"));
-        printf(_("  -h, --help               Prints out this screen\n"));
-        printf("\n");
-}
-
 static struct option set_opts[] = {
         { .name = "perf-bias",  .has_arg = optional_argument,   .flag = NULL,   .val = 'b'},
         { .name = "sched-mc",   .has_arg = optional_argument,   .flag = NULL,   .val = 'm'},
         { .name = "sched-smt",  .has_arg = optional_argument,   .flag = NULL,   .val = 's'},
-        { .name = "help",       .has_arg = no_argument,         .flag = NULL,   .val = 'h'},
         { },
 };
 
 static void print_wrong_arg_exit(void)
 {
         printf(_("invalid or unknown argument\n"));
-        set_help();
         exit(EXIT_FAILURE);
 }
 
@@ -66,12 +52,9 @@ int cmd_set(int argc, char **argv)
 
         params.params = 0;
         /* parameter parsing */
-        while ((ret = getopt_long(argc, argv, "m:s:b:h",
+        while ((ret = getopt_long(argc, argv, "m:s:b:",
                                                 set_opts, NULL)) != -1) {
                 switch (ret) {
-                case 'h':
-                        set_help();
-                        return 0;
                 case 'b':
                         if (params.perf_bias)
                                 print_wrong_arg_exit();
@@ -110,10 +93,8 @@ int cmd_set(int argc, char **argv)
                 }
         };
 
-        if (!params.params) {
-                set_help();
-                return -EINVAL;
-        }
+        if (!params.params)
+                print_wrong_arg_exit();
 
         if (params.sched_mc) {
                 ret = sysfs_set_sched("mc", sched_mc);
diff --git a/tools/power/cpupower/utils/cpupower.c b/tools/power/cpupower/utils/cpupower.c
index 5844ae0f786f..52bee591c1c5 100644
--- a/tools/power/cpupower/utils/cpupower.c
+++ b/tools/power/cpupower/utils/cpupower.c
@@ -11,6 +11,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "builtin.h"
 #include "helpers/helpers.h"
@@ -19,13 +20,12 @@
 struct cmd_struct {
         const char *cmd;
         int (*main)(int, const char **);
-        void (*usage)(void);
         int needs_root;
 };
 
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 
-int cmd_help(int argc, const char **argv);
+static int cmd_help(int argc, const char **argv);
 
 /* Global cpu_info object available for all binaries
  * Info only retrieved from CPU 0
@@ -44,55 +44,66 @@ int be_verbose;
 static void print_help(void);
 
 static struct cmd_struct commands[] = {
-        { "frequency-info",     cmd_freq_info,  freq_info_help, 0       },
-        { "frequency-set",      cmd_freq_set,   freq_set_help,  1       },
-        { "idle-info",          cmd_idle_info,  idle_info_help, 0       },
-        { "set",                cmd_set,        set_help,       1       },
-        { "info",               cmd_info,       info_help,      0       },
-        { "monitor",            cmd_monitor,    monitor_help,   0       },
-        { "help",               cmd_help,       print_help,     0       },
-        /*      { "bench",      cmd_bench,      NULL,           1       }, */
+        { "frequency-info",     cmd_freq_info,  0       },
+        { "frequency-set",      cmd_freq_set,   1       },
+        { "idle-info",          cmd_idle_info,  0       },
+        { "set",                cmd_set,        1       },
+        { "info",               cmd_info,       0       },
+        { "monitor",            cmd_monitor,    0       },
+        { "help",               cmd_help,       0       },
+        /*      { "bench",      cmd_bench,      1       }, */
 };
 
-int cmd_help(int argc, const char **argv)
-{
-        unsigned int i;
-
-        if (argc > 1) {
-                for (i = 0; i < ARRAY_SIZE(commands); i++) {
-                        struct cmd_struct *p = commands + i;
-                        if (strcmp(p->cmd, argv[1]))
-                                continue;
-                        if (p->usage) {
-                                p->usage();
-                                return EXIT_SUCCESS;
-                        }
-                }
-        }
-        print_help();
-        if (argc == 1)
-                return EXIT_SUCCESS; /* cpupower help */
-        return EXIT_FAILURE;
-}
-
 static void print_help(void)
 {
         unsigned int i;
 
 #ifdef DEBUG
-        printf(_("cpupower [ -d ][ -c cpulist ] subcommand [ARGS]\n"));
-        printf(_("  -d, --debug      May increase output (stderr) on some subcommands\n"));
+        printf(_("Usage:\tcpupower [-d|--debug] [-c|--cpu cpulist ] <command> [<args>]\n"));
 #else
-        printf(_("cpupower [ -c cpulist ] subcommand [ARGS]\n"));
+        printf(_("Usage:\tcpupower [-c|--cpu cpulist ] <command> [<args>]\n"));
 #endif
-        printf(_("cpupower --version\n"));
-        printf(_("Supported subcommands are:\n"));
+        printf(_("Supported commands are:\n"));
         for (i = 0; i < ARRAY_SIZE(commands); i++)
                 printf("\t%s\n", commands[i].cmd);
-        printf(_("\nSome subcommands can make use of the -c cpulist option.\n"));
-        printf(_("Look at the general cpupower manpage how to use it\n"));
-        printf(_("and read up the subcommand's manpage whether it is supported.\n"));
-        printf(_("\nUse cpupower help subcommand for getting help for above subcommands.\n"));
+        printf(_("\nNot all commands can make use of the -c cpulist option.\n"));
+        printf(_("\nUse 'cpupower help <command>' for getting help for above commands.\n"));
+}
+
+static int print_man_page(const char *subpage)
+{
+        int len;
+        char *page;
+
+        len = 10; /* enough for "cpupower-" */
+        if (subpage != NULL)
+                len += strlen(subpage);
+
+        page = malloc(len);
+        if (!page)
+                return -ENOMEM;
+
+        sprintf(page, "cpupower");
+        if ((subpage != NULL) && strcmp(subpage, "help")) {
+                strcat(page, "-");
+                strcat(page, subpage);
+        }
+
+        execlp("man", "man", page, NULL);
+
+        /* should not be reached */
+        return -EINVAL;
+}
+
+static int cmd_help(int argc, const char **argv)
+{
+        if (argc > 1) {
+                print_man_page(argv[1]); /* exits within execlp() */
+                return EXIT_FAILURE;
+        }
+
+        print_help();
+        return EXIT_SUCCESS;
 }
 
 static void print_version(void)
diff --git a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
index 6cb8d9e6bb6b..0d6571e418db 100644
--- a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
+++ b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
@@ -43,6 +43,12 @@ static struct cpupower_topology cpu_top;
 /* ToDo: Document this in the manpage */
 static char range_abbr[RANGE_MAX] = { 'T', 'C', 'P', 'M', };
 
+static void print_wrong_arg_exit(void)
+{
+        printf(_("invalid or unknown argument\n"));
+        exit(EXIT_FAILURE);
+}
+
 long long timespec_diff_us(struct timespec start, struct timespec end)
 {
         struct timespec temp;
@@ -56,21 +62,6 @@ long long timespec_diff_us(struct timespec start, struct timespec end)
         return (temp.tv_sec * 1000000) + (temp.tv_nsec / 1000);
 }
 
-void monitor_help(void)
-{
-        printf(_("cpupower monitor: [-m <mon1>,[<mon2>],.. ] command\n"));
-        printf(_("cpupower monitor: [-m <mon1>,[<mon2>],.. ] [ -i interval_sec ]\n"));
-        printf(_("cpupower monitor: -l\n"));
-        printf(_("\t command: pass an arbitrary command to measure specific workload\n"));
-        printf(_("\t -i: time intervall to measure for in seconds (default 1)\n"));
-        printf(_("\t -l: list available CPU sleep monitors (for use with -m)\n"));
-        printf(_("\t -m: show specific CPU sleep monitors only (in same order)\n"));
-        printf(_("\t -h: print this help\n"));
-        printf("\n");
-        printf(_("only one of: -l, -m are allowed\nIf none of them is passed,"));
-        printf(_(" all supported monitors are shown\n"));
-}
-
 void print_n_spaces(int n)
 {
         int x;
@@ -246,7 +237,6 @@ static void parse_monitor_param(char *param)
         if (hits == 0) {
                 printf(_("No matching monitor found in %s, "
                          "try -l option\n"), param);
-                monitor_help();
                 exit(EXIT_FAILURE);
         }
         /* Override detected/registerd monitors array with requested one */
@@ -343,37 +333,27 @@ static void cmdline(int argc, char *argv[])
         int opt;
         progname = basename(argv[0]);
 
-        while ((opt = getopt(argc, argv, "+hli:m:")) != -1) {
+        while ((opt = getopt(argc, argv, "+li:m:")) != -1) {
                 switch (opt) {
-                case 'h':
-                        monitor_help();
-                        exit(EXIT_SUCCESS);
                 case 'l':
-                        if (mode) {
-                                monitor_help();
-                                exit(EXIT_FAILURE);
-                        }
+                        if (mode)
+                                print_wrong_arg_exit();
                         mode = list;
                         break;
                 case 'i':
                         /* only allow -i with -m or no option */
-                        if (mode && mode != show) {
-                                monitor_help();
-                                exit(EXIT_FAILURE);
-                        }
+                        if (mode && mode != show)
+                                print_wrong_arg_exit();
                         interval = atoi(optarg);
                         break;
                 case 'm':
-                        if (mode) {
-                                monitor_help();
-                                exit(EXIT_FAILURE);
-                        }
+                        if (mode)
+                                print_wrong_arg_exit();
                         mode = show;
                         show_monitors_param = optarg;
                         break;
                 default:
-                        monitor_help();
-                        exit(EXIT_FAILURE);
+                        print_wrong_arg_exit();
                 }
         }
         if (!mode)