extras: Add input_id

input_id probes input/event devices for their class (keyboard, keys, mouse,
touchpad, tablet, joystick). This is based on the corresponding hal code in
hald/linux/device.c, input_test_{abs,rel,...}.

This should provide enough functionality to get hal-less X.org working (which
in particular needs to know exactly which devices are touchpads).

Replace the brittle hacks in 60-persistent-input.rules with checking for the
new ID_INPUT_* flags. This keeps the old ID_CLASS properties for now (but they
are to be removed later on).

Note: The current code has several hacks still, which are to be replaced with
proper libudev calls later on.

2 files changed, 155 insertions, 0 deletions

diff --git a/extras/input_id/.gitignore b/extras/input_id/.gitignore
new file mode 100644
index 0000000000..4f33cba4ad
--- /dev/null
+++ b/extras/input_id/.gitignore
@@ -0,0 +1 @@
+input_id
diff --git a/extras/input_id/input_id.c b/extras/input_id/input_id.c
new file mode 100644
index 0000000000..393a05d53a
--- /dev/null
+++ b/extras/input_id/input_id.c
@@ -0,0 +1,154 @@
+/*
+ * input_id - input device classification
+ *
+ * Copyright (C) 2009 Martin Pitt <martin.pitt@ubuntu.com>
+ * Portions Copyright (C) 2004 David Zeuthen, <david@fubar.dk>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with keymap; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <linux/input.h>
+
+/* we must use this kernel-compatible implementation */
+#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)
+
+/* 
+ * Read a capabilities/name file and return bitmask.
+ * @param path File to open
+ * @param bitmask: Output array; must have max_size elements
+ */
+static void get_cap_mask (const char *path, unsigned long *bitmask, size_t max_size)
+{
+	FILE* f;
+        int i;
+	char text[4096];
+	char* word;
+	unsigned long val;
+
+	f = fopen(path, "r");
+	if (f == NULL) {
+		perror("opening caps file");
+		exit(1);
+	}
+	if (fgets(text, sizeof(text), f) == NULL) {
+		perror("fgets");
+		exit(1);
+	}
+	fclose(f);
+	
+        memset (bitmask, 0, max_size);
+	i = 0;
+        while ((word = strrchr(text, ' ')) != NULL) {
+                val = strtoul (word+1, NULL, 16);
+                bitmask[i] = val;
+		*word = '\0';
+		++i;
+        }
+	val = strtoul (text, NULL, 16);
+	bitmask[i] = val;
+}
+
+/* pointer devices */
+static void test_pointers (const unsigned long* bitmask_abs, const unsigned long* bitmask_key, const unsigned long* bitmask_rel)
+{
+	int is_mouse = 0;
+	int is_touchpad = 0;
+
+	if (test_bit (ABS_PRESSURE, bitmask_abs))
+		is_touchpad = 1;
+
+	if (test_bit (ABS_X, bitmask_abs) && test_bit (ABS_Y, bitmask_abs)) {
+		if (test_bit (BTN_STYLUS, bitmask_key))
+			puts("ID_INPUT_TABLET=1");
+		else if (test_bit (BTN_TOUCH, bitmask_key))
+			is_touchpad = 1;
+		else if (test_bit (BTN_TRIGGER, bitmask_key) || 
+			 test_bit (BTN_A, bitmask_key) || 
+			 test_bit (BTN_1, bitmask_key))
+			puts("ID_INPUT_JOYSTICK=1");
+		else if (test_bit (BTN_MOUSE, bitmask_key))
+			/* This path is taken by VMware's USB mouse, which has
+			 * absolute axes, but no touch/pressure button. */
+			is_mouse = 1;
+	}
+
+	if (test_bit (REL_X, bitmask_rel) && test_bit (REL_Y, bitmask_rel))
+		is_mouse = 1;
+
+	if (is_mouse)
+		puts("ID_INPUT_MOUSE=1");
+	if (is_touchpad)
+		puts("ID_INPUT_TOUCHPAD=1");
+}
+
+/* key like devices */
+static void test_key (const unsigned long* bitmask_key)
+{
+	unsigned i;
+	unsigned long acc;
+	unsigned long mask;
+
+	/* do we have any KEY_* capability? */
+	acc = 0;
+	for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i)
+	    acc |= bitmask_key[i];
+	if (acc > 0)
+		puts("ID_INPUT_KEY=1");
+
+	/* 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 */
+	mask = 0xFFFFFFFE;
+	if ((bitmask_key[0] & mask) == mask)
+		puts("ID_INPUT_KEYBOARD=1");
+}
+
+int main (int argc, char** argv)
+{
+	char capfile[PATH_MAX];
+	unsigned long bitmask_abs[NBITS(ABS_MAX)];
+	unsigned long bitmask_key[NBITS(KEY_MAX)];
+        unsigned long bitmask_rel[NBITS(REL_MAX)];
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s <device path (without /sys)>\n", argv[0]);
+		exit(1);
+	}
+
+	/* Use this as a flag that input devices were detected, so that this
+	 * program doesn't need to be called more than once per device */
+	puts("ID_INPUT=1");
+
+	snprintf(capfile, sizeof(capfile), "/sys/%s/device/capabilities/abs", argv[1]);
+	get_cap_mask (capfile, bitmask_abs, sizeof (bitmask_abs));
+	snprintf(capfile, sizeof(capfile), "/sys/%s/device/capabilities/rel", argv[1]);
+	get_cap_mask (capfile, bitmask_rel, sizeof (bitmask_rel));
+	snprintf(capfile, sizeof(capfile), "/sys/%s/device/capabilities/key", argv[1]);
+	get_cap_mask (capfile, bitmask_key, sizeof (bitmask_key));
+
+	test_pointers(bitmask_abs, bitmask_key, bitmask_rel);
+
+	test_key(bitmask_key);
+
+	return 0;
+}