Initial commit

5 files changed, 282 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
new file mode 100644
index 0000000..8983232
--- /dev/null
+++ b/Makefile.am
@@ -0,0 +1,5 @@
+lib_LTLIBRARIES = libbacklight.la
+libbacklight_la_SOURCES = libbacklight.c libbacklight.h
+libatasmart_la_CFLAGS = $(PCIACCESS_CFLAGS)
+
+ACLOCAL_AMFLAGS = -I m4
\ No newline at end of file
diff --git a/configure.ac b/configure.ac
new file mode 100644
index 0000000..f37d0f3
--- /dev/null
+++ b/configure.ac
@@ -0,0 +1,15 @@
+AC_PREREQ(2.63)
+
+AC_INIT([libbacklight], 0.01, [mjg@redhat.com])
+AC_CONFIG_SRCDIR([libbacklight.c])
+AC_CONFIG_MACRO_DIR(m4)
+
+AM_INIT_AUTOMAKE([foreign 1.11 -Wall])
+
+AC_CANONICAL_HOST
+AM_SILENT_RULES([yes])
+
+AC_PROG_CC
+AC_PROG_LIBTOOL
+PKG_CHECK_MODULES([PCIACCESS], [pciaccess >= 0.11.0])
+AC_CONFIG_FILES([Makefile libbacklight.pc])
\ No newline at end of file
diff --git a/libbacklight.c b/libbacklight.c
new file mode 100644
index 0000000..2354829
--- /dev/null
+++ b/libbacklight.c
@@ -0,0 +1,231 @@
+#define _GNU_SOURCE
+
+#include <libbacklight.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <malloc.h>
+#include <string.h>
+
+static const char *output_names[] = { "None",
+                                      "VGA",
+                                      "DVI",
+                                      "DVI",
+                                      "DVI",
+                                      "Composite",
+                                      "TV",
+                                      "LVDS",
+                                      "CTV",
+                                      "DIN",
+                                      "DP",
+                                      "HDMI",
+                                      "HDMI",
+};
+
+static long backlight_get(struct backlight *backlight, char *node)
+{
+	char buffer[100];
+	char *path;
+	int fd;
+	long value, ret;
+
+	asprintf(&path, "%s/%s", backlight->path, node);
+	fd = open(path, O_RDONLY);
+	if (fd < 0) {
+		ret = -1;
+		goto out;
+	}
+
+	ret = read(fd, &buffer, sizeof(buffer));
+	if (ret < 1) {
+		ret = -1;
+		goto out;
+	}
+
+	value = strtol(buffer, NULL, 10);
+	ret = value;
+out:
+	close(fd);
+	if (path)
+		free(path);
+	return ret;
+}
+
+long backlight_get_brightness(struct backlight *backlight)
+{
+	return backlight_get(backlight, "brightness");
+}
+
+long backlight_get_max_brightness(struct backlight *backlight)
+{
+	return backlight_get(backlight, "max_brightness");
+}
+
+long backlight_get_actual_brightness(struct backlight *backlight)
+{
+	return backlight_get(backlight, "actual_brightness");
+}
+
+long backlight_set_brightness(struct backlight *backlight, long brightness)
+{
+	char *path;
+	char *buffer = NULL;
+	int fd;
+	long value, ret;
+
+	asprintf(&path, "%s/%s", backlight->path, "brightness");
+	fd = open(path, O_RDWR);
+	if (fd < 0) {
+		ret = -1;
+		goto out;
+	}
+
+	ret = read(fd, &buffer, sizeof(buffer));
+	if (ret < 1) {
+		ret = -1;
+		goto out;
+	}
+
+	asprintf(&buffer, "%ld", brightness);
+	ret = write(fd, buffer, strlen(buffer));
+	if (ret < 0) {
+		ret = -1;
+		goto out;
+	}
+
+	ret = backlight_get_brightness(backlight);
+out:
+	if (buffer)
+		free(buffer);
+	if (path)
+		free(path);
+	close(fd);
+	return ret;
+}
+
+struct backlight *backlight_init(struct pci_device *dev, int card,
+				 int connector_type, int connector_type_id)
+{
+	char *pci_name;
+	char *drm_name;
+	char *chosen_path = NULL;
+	DIR *backlights;
+	struct dirent *entry;
+	enum backlight_type type = 0;
+	char buffer[100];
+	struct backlight *backlight;
+
+	asprintf(&pci_name, "%04x:%02x:%02x.%d", dev->domain, dev->bus,
+		 dev->dev, dev->func);
+	asprintf(&drm_name, "card%d-%s-%d", card, output_names[connector_type],
+		 connector_type_id);
+
+	backlights = opendir("/sys/class/backlight");
+
+	if (!backlights)
+		return NULL;
+
+	while ((entry = readdir(backlights))) {
+		char *backlight_path;
+		char *parent;
+		char *path;
+		enum backlight_type entry_type;
+		int fd, ret;
+
+		if (entry->d_name[0] == '.')
+			continue;
+
+		asprintf(&backlight_path, "%s/%s", "/sys/class/backlight",
+			 entry->d_name);
+		asprintf(&path, "%s/%s", backlight_path, "type");
+		fd = open(path, O_RDONLY);
+
+		if (fd < 0)
+			goto out;
+
+		ret = read (fd, &buffer, sizeof(buffer));
+		close (fd);
+
+		if (ret < 1)
+			goto out;
+
+		buffer[ret] = '\0';
+
+		if (!strncmp(buffer, "raw\n", sizeof(buffer)))
+			entry_type = BACKLIGHT_RAW;
+		else if (!strncmp(buffer, "platform\n", sizeof(buffer)))
+			entry_type = BACKLIGHT_PLATFORM;
+		else if (!strncmp(buffer, "firmware\n", sizeof(buffer)))
+			entry_type = BACKLIGHT_FIRMWARE;
+		else
+			goto out;
+
+		free (path);
+		asprintf(&path, "%s/%s", backlight_path, "device");
+		ret = readlink(path, buffer, sizeof(buffer));
+
+		if (ret < 0)
+			goto out;
+
+		parent = basename(buffer);
+
+		if (entry_type == BACKLIGHT_RAW) {
+			if (strcmp(drm_name, parent) &&
+			    strcmp(pci_name, parent)) {
+				goto out;
+			}
+		}
+
+		if (entry_type == BACKLIGHT_FIRMWARE) {                   
+			/* Older kernels won't provide a valid path here... */
+			unsigned int domain, bus, device, function;
+			ret = sscanf(parent, "%04x:%02x:%02x.%u", &domain, &bus,
+				     &device, &function);
+			if (ret == 4) {                   
+				if (strcmp(pci_name, parent))
+					goto out;
+			}
+		}
+
+		if (entry_type < type)
+			goto out;
+
+		type = entry_type;
+
+		if (chosen_path)
+			free(chosen_path);
+		chosen_path = strdup(backlight_path);
+
+	out:
+		free(backlight_path);
+		free(path);
+	}
+
+	if (!chosen_path)
+		return NULL;
+
+	backlight = malloc(sizeof(struct backlight));
+
+	if (!backlight)
+		goto err;
+
+	backlight->path = chosen_path;
+	backlight->type = type;
+
+	backlight->max_brightness = backlight_get_max_brightness(backlight);
+	if (backlight->max_brightness < 0)
+		goto err;
+
+	backlight->brightness = backlight_get_actual_brightness(backlight);
+	if (backlight->brightness < 0)
+		goto err;
+
+	return backlight;
+err:
+	if (chosen_path)
+		free(chosen_path);
+	free (backlight);
+	return NULL;
+}
diff --git a/libbacklight.h b/libbacklight.h
new file mode 100644
index 0000000..20981bd
--- /dev/null
+++ b/libbacklight.h
@@ -0,0 +1,20 @@
+#include <pciaccess.h>
+
+enum backlight_type {
+	BACKLIGHT_RAW,
+	BACKLIGHT_PLATFORM,
+	BACKLIGHT_FIRMWARE,
+};
+
+struct backlight {
+	char *path;
+	int max_brightness;
+	int brightness;
+	enum backlight_type type;
+};
+
+struct backlight *backlight_init(struct pci_device *dev, int card,
+				 int connector_type, int connector_type_id);
+long backlight_get_brightness(struct backlight *backlight);
+long backlight_get_max_brightness(struct backlight *backlight);
+long backlight_set_brightness(struct backlight *backlight, long brightness);
diff --git a/libbacklight.pc.in b/libbacklight.pc.in
new file mode 100644
index 0000000..f70bc0f
--- /dev/null
+++ b/libbacklight.pc.in
@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=${prefix}
+libdir=@libdir@
+includedir=${prefix}/include
+
+Name: libbacklight
+Description: Linux backlight interface library
+Version: @PACKAGE_VERSION@
+Libs: -L${libdir} -lbacklight
+Cflags: -I${includedir}
+Requires: