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Fixed input device detection on systems that aren't running the udev …

…daemon
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slouken committed Oct 15, 2014
1 parent 639b39c commit 89127c2d703cff4b14e210834273265742a716ff
Showing with 114 additions and 5 deletions.
  1. +112 −5 src/core/linux/SDL_udev.c
  2. +2 −0 src/core/linux/SDL_udev.h
@@ -25,18 +25,19 @@
* udevadm info --query=all -n input/event3 (for a keyboard, mouse, etc)
* udevadm info --query=property -n input/event2
*/

#include "SDL_udev.h"

#ifdef SDL_USE_LIBUDEV

#include <linux/input.h>

#include "SDL.h"

static char* SDL_UDEV_LIBS[] = { "libudev.so.1", "libudev.so.0" };

#define _THIS SDL_UDEV_PrivateData *_this
static _THIS = NULL;

#include "SDL.h"

static SDL_bool SDL_UDEV_load_sym(const char *fn, void **addr);
static int SDL_UDEV_load_syms(void);
static SDL_bool SDL_UDEV_hotplug_update_available(void);
@@ -64,7 +65,9 @@ SDL_UDEV_load_syms(void)
SDL_UDEV_SYM(udev_device_get_action);
SDL_UDEV_SYM(udev_device_get_devnode);
SDL_UDEV_SYM(udev_device_get_subsystem);
SDL_UDEV_SYM(udev_device_get_parent_with_subsystem_devtype);
SDL_UDEV_SYM(udev_device_get_property_value);
SDL_UDEV_SYM(udev_device_get_sysattr_value);
SDL_UDEV_SYM(udev_device_new_from_syspath);
SDL_UDEV_SYM(udev_device_unref);
SDL_UDEV_SYM(udev_enumerate_add_match_property);
@@ -274,6 +277,109 @@ SDL_UDEV_LoadLibrary(void)
return retval;
}

#define BITS_PER_LONG (sizeof(unsigned long) * 8)
#define NBITS(x) ((((x)-1)/BITS_PER_LONG)+1)
#define OFF(x) ((x)%BITS_PER_LONG)
#define BIT(x) (1UL<<OFF(x))
#define LONG(x) ((x)/BITS_PER_LONG)
#define test_bit(bit, array) ((array[LONG(bit)] >> OFF(bit)) & 1)

static void get_caps(struct udev_device *dev, struct udev_device *pdev, const char *attr, unsigned long *bitmask, size_t bitmask_len)
{
const char *value;
char text[4096];
char *word;
int i;
unsigned long v;

SDL_memset(bitmask, 0, bitmask_len*sizeof(*bitmask));
value = _this->udev_device_get_sysattr_value(pdev, attr);
if (!value) {
return;
}

SDL_strlcpy(text, value, sizeof(text));
i = 0;
while ((word = SDL_strrchr(text, ' ')) != NULL) {
v = SDL_strtoul(word+1, NULL, 16);
if (i < bitmask_len) {
bitmask[i] = v;
}
++i;
*word = '\0';
}
v = SDL_strtoul(text, NULL, 16);
if (i < bitmask_len) {
bitmask[i] = v;
}
}

static int
guess_device_class(struct udev_device *dev)
{
int devclass = 0;
struct udev_device *pdev;
unsigned long bitmask_ev[NBITS(EV_MAX)];
unsigned long bitmask_abs[NBITS(ABS_MAX)];
unsigned long bitmask_key[NBITS(KEY_MAX)];
unsigned long bitmask_rel[NBITS(REL_MAX)];
unsigned long keyboard_mask;

/* walk up the parental chain until we find the real input device; the
* argument is very likely a subdevice of this, like eventN */
pdev = dev;
while (pdev && !_this->udev_device_get_sysattr_value(pdev, "capabilities/ev")) {
pdev = _this->udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
}
if (!pdev) {
return 0;
}

get_caps(dev, pdev, "capabilities/ev", bitmask_ev, SDL_arraysize(bitmask_ev));
get_caps(dev, pdev, "capabilities/abs", bitmask_abs, SDL_arraysize(bitmask_abs));
get_caps(dev, pdev, "capabilities/rel", bitmask_rel, SDL_arraysize(bitmask_rel));
get_caps(dev, pdev, "capabilities/key", bitmask_key, SDL_arraysize(bitmask_key));

if (test_bit(EV_ABS, bitmask_ev) &&
test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs)) {
if (test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key)) {
; /* ID_INPUT_TABLET */
} else if (test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key)) {
; /* ID_INPUT_TOUCHPAD */
} else if (test_bit(BTN_MOUSE, bitmask_key)) {
devclass |= SDL_UDEV_DEVICE_MOUSE; /* ID_INPUT_MOUSE */
} else if (test_bit(BTN_TOUCH, bitmask_key)) {
; /* ID_INPUT_TOUCHSCREEN */
} else if (test_bit(BTN_TRIGGER, bitmask_key) ||
test_bit(BTN_A, bitmask_key) ||
test_bit(BTN_1, bitmask_key) ||
test_bit(ABS_RX, bitmask_abs) ||
test_bit(ABS_RY, bitmask_abs) ||
test_bit(ABS_RZ, bitmask_abs) ||
test_bit(ABS_THROTTLE, bitmask_abs) ||
test_bit(ABS_RUDDER, bitmask_abs) ||
test_bit(ABS_WHEEL, bitmask_abs) ||
test_bit(ABS_GAS, bitmask_abs) ||
test_bit(ABS_BRAKE, bitmask_abs)) {
devclass |= SDL_UDEV_DEVICE_JOYSTICK; /* ID_INPUT_JOYSTICK */
}
}

if (test_bit(EV_REL, bitmask_ev) &&
test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel) &&
test_bit(BTN_MOUSE, bitmask_key)) {
devclass |= SDL_UDEV_DEVICE_MOUSE; /* ID_INPUT_MOUSE */
}

/* the first 32 bits are ESC, numbers, and Q to D; if we have all of
* those, consider it a full keyboard; do not test KEY_RESERVED, though */
keyboard_mask = 0xFFFFFFFE;
if ((bitmask_key[0] & keyboard_mask) == keyboard_mask)
devclass |= SDL_UDEV_DEVICE_KEYBOARD; /* ID_INPUT_KEYBOARD */

return devclass;
}

static void
device_event(SDL_UDEV_deviceevent type, struct udev_device *dev)
{
@@ -308,7 +414,7 @@ device_event(SDL_UDEV_deviceevent type, struct udev_device *dev)
}

if (devclass == 0) {
// Fall back to old style input classes
/* Fall back to old style input classes */
val = _this->udev_device_get_property_value(dev, "ID_CLASS");
if (val != NULL) {
if (SDL_strcmp(val, "joystick") == 0) {
@@ -321,7 +427,8 @@ device_event(SDL_UDEV_deviceevent type, struct udev_device *dev)
return;
}
} else {
return;
/* We could be linked with libudev on a system that doesn't have udev running */
devclass = guess_device_class(dev);
}
}
} else {
@@ -75,7 +75,9 @@ typedef struct SDL_UDEV_PrivateData
const char *(*udev_device_get_action)(struct udev_device *);
const char *(*udev_device_get_devnode)(struct udev_device *);
const char *(*udev_device_get_subsystem)(struct udev_device *);
struct udev_device *(*udev_device_get_parent_with_subsystem_devtype)(struct udev_device *udev_device, const char *subsystem, const char *devtype);
const char *(*udev_device_get_property_value)(struct udev_device *, const char *);
const char *(*udev_device_get_sysattr_value)(struct udev_device *udev_device, const char *sysattr);
struct udev_device *(*udev_device_new_from_syspath)(struct udev *, const char *);
void (*udev_device_unref)(struct udev_device *);
int (*udev_enumerate_add_match_property)(struct udev_enumerate *, const char *, const char *);

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