--- /dev/null
+/*
+ * libbacklight - userspace interface to Linux backlight control
+ *
+ * Copyright © 2012 Intel Corporation
+ * Copyright 2010 Red Hat <mjg@redhat.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Matthew Garrett <mjg@redhat.com>
+ * Tiago Vignatti <vignatti@freedesktop.org>
+ */
+
+#define _GNU_SOURCE
+
+#include <libbacklight.h>
+#include <stdio.h>
+#include <linux/types.h>
+#include <dirent.h>
+#include <drm/drm_mode.h>
+#include <fcntl.h>
+#include <malloc.h>
+#include <string.h>
+#include <errno.h>
+
+static const char *output_names[] = { "Unknown",
+ "VGA",
+ "DVI-I",
+ "DVI-D",
+ "DVI-A",
+ "Composite",
+ "SVIDEO",
+ "LVDS",
+ "Component",
+ "9-pin DIN",
+ "DisplayPort"
+ "HDMI Type A",
+ "HDMI Type B",
+ "TV",
+ "Embedded DisplayPort"
+};
+
+static long backlight_get(struct backlight *backlight, char *node)
+{
+ char buffer[100];
+ char *path;
+ int fd;
+ long value, ret;
+
+ if (asprintf(&path, "%s/%s", backlight->path, node) < 0)
+ return -ENOMEM
+;
+ 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 ret;
+
+ if (asprintf(&path, "%s/%s", backlight->path, "brightness") < 0)
+ return -ENOMEM;
+
+ 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;
+ }
+
+ if (asprintf(&buffer, "%ld", brightness) < 0)
+ return -ENOMEM;
+
+ ret = write(fd, buffer, strlen(buffer));
+ if (ret < 0) {
+ ret = -1;
+ goto out;
+ }
+
+ ret = backlight_get_brightness(backlight);
+ backlight->brightness = ret;
+out:
+ if (buffer)
+ free(buffer);
+ if (path)
+ free(path);
+ close(fd);
+ return ret;
+}
+
+void backlight_destroy(struct backlight *backlight)
+{
+ if (!backlight)
+ return;
+
+ if (backlight->path)
+ free(backlight->path);
+
+ free(backlight);
+}
+
+struct backlight *backlight_init(struct udev_device *drm_device,
+ uint32_t connector_type)
+{
+ const char *syspath = NULL;
+ char *pci_name = NULL;
+ char *chosen_path = NULL;
+ char *path = NULL;
+ DIR *backlights;
+ struct dirent *entry;
+ enum backlight_type type = 0;
+ char buffer[100];
+ struct backlight *backlight;
+ int err, ret;
+
+ if (!drm_device)
+ return NULL;
+
+ syspath = udev_device_get_syspath(drm_device);
+ if (!syspath)
+ return NULL;
+
+ if (asprintf(&path, "%s/%s", syspath, "device") < 0)
+ return NULL;
+
+ ret = readlink(path, buffer, sizeof(buffer));
+ free(path);
+ if (ret < 0)
+ return NULL;
+
+ buffer[ret] = '\0';
+ pci_name = basename(buffer);
+
+ if (connector_type <= 0)
+ return NULL;
+
+ backlights = opendir("/sys/class/backlight");
+ if (!backlights)
+ return NULL;
+
+ /* Find the "best" backlight for the device. Firmware
+ interfaces are preferred over platform interfaces are
+ preferred over raw interfaces. For raw interfaces we'll
+ check if the device ID in the form of pci match, while
+ for firmware interfaces we require the pci ID to
+ match. It's assumed that platform interfaces always match,
+ since we can't actually associate them with IDs.
+
+ A further awkwardness is that, while it's theoretically
+ possible for an ACPI interface to include support for
+ changing the backlight of external devices, it's unlikely
+ to ever be done. It's effectively impossible for a platform
+ interface to do so. So if we get asked about anything that
+ isn't LVDS or eDP, we pretty much have to require that the
+ control be supplied via a raw interface */
+
+ while ((entry = readdir(backlights))) {
+ char *backlight_path;
+ char *parent;
+ enum backlight_type entry_type;
+ int fd;
+
+ if (entry->d_name[0] == '.')
+ continue;
+
+ if (asprintf(&backlight_path, "%s/%s", "/sys/class/backlight",
+ entry->d_name) < 0)
+ return NULL;
+
+ if (asprintf(&path, "%s/%s", backlight_path, "type") < 0)
+ return NULL;
+
+ 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;
+
+ if (connector_type != DRM_MODE_CONNECTOR_LVDS &&
+ connector_type != DRM_MODE_CONNECTOR_eDP) {
+ /* External displays are assumed to require
+ gpu control at the moment */
+ if (entry_type != BACKLIGHT_RAW)
+ goto out;
+ }
+
+ free (path);
+
+ if (asprintf(&path, "%s/%s", backlight_path, "device") < 0)
+ return NULL;
+
+ ret = readlink(path, buffer, sizeof(buffer));
+
+ if (ret < 0)
+ goto out;
+
+ buffer[ret] = '\0';
+
+ parent = basename(buffer);
+
+ /* Perform matching for raw and firmware backlights -
+ platform backlights have to be assumed to match */
+ if (entry_type == BACKLIGHT_RAW ||
+ entry_type == BACKLIGHT_FIRMWARE) {
+ if (!(pci_name && !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;
+}
projects / profile / ivi / weston-ivi-shell.git / commitdiff