Imported evdev helper functions to mce source tree

evdev.c

@@ -0,0 +1,325 @@
+/* ------------------------------------------------------------------------- *
+ * Copyright (C) 2012-2013 Jolla Ltd.
+ * Contact: Simo Piiroinen <simo.piiroinen@jollamobile.com>
+ * License: GPLv2
+ * ------------------------------------------------------------------------- */
+
+#include "evdev.h"
+#include "mce-log.h"
+
+#include <linux/input.h>
+
+#include <sys/ioctl.h>
+
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <limits.h>
+#include <stdlib.h>
+
+/** Number of elements in array of fixed size */
+#define numof(a) (sizeof(a)/sizeof*(a))
+
+/* Autogenerated lookup tables */
+#include "evdev.inc"
+
+/** Number to string lookup with bounds checking
+ */
+static const char *lookup(const char * const *lut, size_t cnt, int val)
+{
+  return ((size_t)val < cnt) ? lut[val] : 0;
+}
+
+/* Internal helper functions for looking up event codes by type */
+static const char * syn_name(int ecode)
+{
+  return lookup(lut_syn, numof(lut_syn), ecode) ?: "SYN_???";
+}
+
+static const char * key_name(int ecode)
+{
+  return lookup(lut_key, numof(lut_key), ecode) ?: "KEY_???";
+}
+
+static const char * rel_name(int ecode)
+{
+  return lookup(lut_rel, numof(lut_rel), ecode) ?: "REL_???";
+}
+
+static const char * abs_name(int ecode)
+{
+  return lookup(lut_abs, numof(lut_abs), ecode) ?: "ABS_???";
+}
+
+static const char * msc_name(int ecode)
+{
+  return lookup(lut_msc, numof(lut_msc), ecode) ?: "MSC_???";
+}
+
+static const char * led_name(int ecode)
+{
+  return lookup(lut_led, numof(lut_led), ecode) ?: "LED_???";
+}
+
+static const char * rep_name(int ecode)
+{
+  return lookup(lut_rep, numof(lut_rep), ecode) ?: "REP_???";
+}
+
+static const char * snd_name(int ecode)
+{
+  return lookup(lut_snd, numof(lut_snd), ecode) ?: "SND_???";
+}
+
+static const char * sw_name(int ecode)
+{
+  return lookup(lut_sw, numof(lut_sw), ecode) ?: "SW_???";
+}
+
+static const char * ff_name(int ecode)
+{
+  return lookup(lut_ff, numof(lut_ff), ecode) ?: "FF_???";
+}
+
+static const char * pwr_name(int ecode)
+{
+  (void)ecode; // not used
+  return "PWR_???";
+  //return lookup(lut_pwr, numof(lut_pwr), ecode) ?: "PWR_???";
+}
+
+/** How many "unsigned long" elements bitmap needs to cover bc bits */
+#define BMAP_SIZE(bc) (((bc)+LONG_BIT-1)/LONG_BIT)
+
+/** Test a bit in array of unsigned longs
+ *
+ * @param bmap array of longs
+ * @param bi   bit index
+ *
+ * @return 1 if bit is set, 0 if not
+ */
+static int bit_is_set(unsigned long *bmap, size_t bi)
+{
+  size_t        i = bi / LONG_BIT;
+  unsigned long m = 1ul << (bi % LONG_BIT);
+  return (bmap[i] & m) != 0;
+}
+
+/** Helper for getting terminal width
+ *
+ * @return guestimate of number of characters per line
+ */
+static int get_terminal_width(void)
+{
+  int res;
+  struct winsize ws;
+  const char *env;
+
+  if( (env = getenv("COLUMNS")) )
+  {
+    if( (res = strtol(env, 0, 10)) > 10 )
+    {
+      return res;
+    }
+  }
+
+  res = 80;
+
+  if( ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1 ||
+      ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) != -1 ||
+      ioctl(STDIN_FILENO,  TIOCGWINSZ, &ws) != -1 )
+  {
+    res = ws.ws_col;
+  }
+  return res;
+}
+
+/** Lookup human readable name for input event code
+ *
+ * @param etype input event type
+ * @param ecode input event code
+ *
+ * @return Name of input event code as string
+ */
+const char *evdev_get_event_code_name(int etype, int ecode)
+{
+  typedef const char *(*lookup_fn)(int);
+
+  static const lookup_fn lut[] =
+  {
+    [EV_SYN] = syn_name,
+    [EV_KEY] = key_name,
+    [EV_REL] = rel_name,
+    [EV_ABS] = abs_name,
+    [EV_MSC] = msc_name,
+    [EV_SW]  = sw_name,
+    [EV_LED] = led_name,
+    [EV_SND] = snd_name,
+    [EV_REP] = rep_name,
+    [EV_FF]  = ff_name,
+    [EV_PWR] = pwr_name,
+  };
+
+  if( (size_t)etype < numof(lut) && lut[etype] )
+  {
+    return lut[etype](ecode);
+  }
+  return "???_???";
+}
+
+/** Lookup human readable name for input event type
+ *
+ * @param etype input event type
+ *
+ * @return Name of input event type as string
+ */
+const char * evdev_get_event_type_name(int etype)
+{
+  return lookup(lut_ev, numof(lut_ev), etype) ?: "EV_???";
+}
+
+/** Open input device in read only mode
+ *
+ * @param path input device path to open
+ *
+ * @returns file descriptor on success, or
+ *          -1 if the file can't be opened / it is not an input device
+ */
+int evdev_open_device(const char *path)
+{
+  int fd;
+
+  if( (fd = open(path, O_RDONLY)) != -1 )
+  {
+    int vers = 0;
+    if( ioctl(fd, EVIOCGVERSION, &vers) == -1)
+    {
+      // assume this is not an input device node then
+      close(fd), fd = -1;
+    }
+  }
+
+  return fd;
+}
+
+/** Write input device information to stdout
+ *
+ * @param fd file descriptor
+ *
+ * @return 0 on success, or -1 in case of errors
+ */
+int evdev_identify_device(int fd)
+{
+  int err = -1;
+  int vers;
+  int cols;
+  unsigned long bmap_type[BMAP_SIZE(EV_CNT)];
+  unsigned long bmap_code[BMAP_SIZE(KEY_CNT)];
+  char path[256];
+  int n;
+
+  if( fd < 0 )
+  {
+    goto cleanup;
+  }
+
+  snprintf(path, sizeof path, "/proc/self/fd/%d", fd);
+  if( (n = readlink(path, path, sizeof path - 1)) <= 0 )
+  {
+    strcpy(path, "unknown");
+  }
+  else
+  {
+    path[n] = 0;
+  }
+
+  // is it evdev file descriptor?
+  if( ioctl(fd, EVIOCGVERSION, &vers) == -1)
+  {
+    goto cleanup;
+  }
+
+  // device name
+  {
+    char name[256];;
+    if( ioctl(fd, EVIOCGNAME(sizeof(name)), name) == -1 )
+    {
+      mce_log(LL_WARN, "%s: EVIOCGNAME: %m", path);
+      strcpy(name, "Unknown");
+    }
+    printf("Name: \"%s\"\n", name);
+  }
+
+  // device id
+  {
+    unsigned short id[4];
+    if( ioctl(fd, EVIOCGID, id) == -1 )
+    {
+      mce_log(LL_WARN, "%s: EVIOCGID: %m", path);
+      memset(id, 0, sizeof id);
+    }
+    printf("ID: bus 0x%x, vendor, 0x%x, product 0x%x, version 0x%x\n",
+           id[ID_BUS], id[ID_VENDOR], id[ID_PRODUCT], id[ID_VERSION]);
+  }
+
+  // get bitmask of supported event types
+  memset(bmap_type, 0, sizeof(bmap_type));
+  if( ioctl(fd, EVIOCGBIT(0, EV_CNT), bmap_type) == -1 )
+  {
+    mce_log(LL_WARN, "%s: EVIOCGBIT(0): %m", path );
+    goto cleanup;
+  }
+
+  // guestimate how wide event code listing we can make
+  cols = get_terminal_width() - 10;
+  if( cols < 32 ) cols = 72;
+
+  // list supported event types and codes
+  for( int etype = 0; etype < EV_CNT; ++etype )
+  {
+    if( !bit_is_set(bmap_type, etype) )
+    {
+      continue;
+    }
+
+    printf("Type 0x%02x (%s)\n", etype, evdev_get_event_type_name(etype));
+
+    if( etype == EV_SYN )
+    {
+      // EVIOCGBIT(0, n) returns event types supported, not
+      // what SYN_xxx codes are supported ... skip it
+      continue;
+    }
+
+    memset(bmap_code, 0, sizeof(bmap_code));
+    if( ioctl(fd, EVIOCGBIT(etype, KEY_CNT), bmap_code) == -1 )
+    {
+      mce_log(LL_WARN, "%s: EVIOCGBIT(%s): %m", path,
+              evdev_get_event_type_name(etype));
+      continue;
+    }
+
+    int len = 0;
+    for( int ecode = 0; ecode < KEY_CNT; ++ecode )
+    {
+      if( bit_is_set(bmap_code, ecode) )
+      {
+        const char *tag = evdev_get_event_code_name(etype, ecode);
+        int add = strlen(tag) + 1;
+
+        if( len == 0 ) printf("\t");
+        else if( len+add > cols ) printf("\n\t"), len = 0;
+
+        len += add, printf(" %s", tag);
+      }
+    }
+    if( len ) printf("\n");
+  }
+
+  err = 0;
+
+cleanup:
+
+  return err;
+}

evdev.h

@@ -0,0 +1,26 @@
+/* ------------------------------------------------------------------------- *
+ * Copyright (C) 2012-2013 Jolla Ltd.
+ * Contact: Simo Piiroinen <simo.piiroinen@jollamobile.com>
+ * License: GPLv2
+ * ------------------------------------------------------------------------- */
+
+#ifndef EVDEV_H_
+#define EVDEV_H_
+
+#ifdef __cplusplus
+extern "C" {
+#elif 0
+} /* fool JED indentation ... */
+#endif
+
+const char *evdev_get_event_code_name(int etype, int ecode);
+const char *evdev_get_event_type_name(int etype);
+
+int evdev_open_device(const char *path);
+int evdev_identify_device(int fd);
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif /* EVDEV_H_ */