tests: add backlight test

Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com>

tests/Makefile.am

@@ -1,6 +1,6 @@
 if BUILD_TESTS
 
-noinst_PROGRAMS = matrix-test
+noinst_PROGRAMS = matrix-test setbacklight
 
 endif
 
@@ -13,3 +13,10 @@ matrix_test_SOURCES =				\
 	$(top_srcdir)/src/matrix.c		\
 	$(top_srcdir)/src/matrix.h
 matrix_test_LDADD = -lm -lrt
+
+setbacklight_SOURCES =				\
+	setbacklight.c				\
+	$(top_srcdir)/src/libbacklight.c	\
+	$(top_srcdir)/src/libbacklight.h
+
+setbacklight_LDADD = -ludev -ldrm

tests/setbacklight.c

@@ -0,0 +1,191 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission.  The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Tiago Vignatti
+ */
+/*
+ * \file setbacklight.c
+ * Test program to get a backlight connector and set its brightness value.
+ * Queries for the connectors id can be performed using drm/tests/modeprint
+ * program.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include "libbacklight.h"
+
+static uint32_t
+get_drm_connector_type(struct udev_device *drm_device, uint32_t connector_id)
+{
+	const char *filename;
+	int fd, i, connector_type;
+	drmModeResPtr res;
+	drmModeConnectorPtr connector;
+
+	filename = udev_device_get_devnode(drm_device);
+	fd = open(filename, O_RDWR | O_CLOEXEC);
+	if (fd < 0) {
+		printf("couldn't open drm_device\n");
+		return -1;
+	}
+
+	res = drmModeGetResources(fd);
+	if (res == 0) {
+		printf("Failed to get resources from card\n");
+		close(fd);
+		return -1;
+	}
+
+	for (i = 0; i < res->count_connectors; i++) {
+		connector = drmModeGetConnector(fd, res->connectors[i]);
+		if (!connector)
+			continue;
+
+		if ((connector->connection == DRM_MODE_DISCONNECTED) ||
+		    (connector->connector_id != connector_id)) {
+			drmModeFreeConnector(connector);
+			continue;
+		}
+
+		connector_type = connector->connector_type;
+		drmModeFreeConnector(connector);
+		drmModeFreeResources(res);
+
+		return connector_type;
+	}
+
+	drmModeFreeResources(res);
+	return -1;
+}
+
+/* returns a value between 0-255 range, where higher is brighter */
+static uint32_t
+get_normalized_backlight(struct backlight *backlight)
+{
+	long brightness, max_brightness;
+	long norm;
+
+	brightness = backlight_get_brightness(backlight);
+	max_brightness = backlight_get_max_brightness(backlight);
+
+	/* convert it to a scale of 0 to 255 */
+	norm = (brightness * 255)/(max_brightness);
+
+	return (int) norm;
+}
+
+static void
+set_backlight(struct udev_device *drm_device, int connector_id, int blight)
+{
+	int connector_type;
+	long max_brightness, brightness, actual_brightness;
+	struct backlight *backlight;
+	long new_blight;
+
+	connector_type = get_drm_connector_type(drm_device, connector_id);
+	if (connector_type < 0)
+		return;
+
+	backlight = backlight_init(drm_device, connector_type);
+	if (!backlight) {
+		printf("backlight adjust failed\n");
+		return;
+	}
+
+	max_brightness = backlight_get_max_brightness(backlight);
+	printf("Max backlight: %ld\n", max_brightness);
+
+	brightness = backlight_get_brightness(backlight);
+	printf("Cached backlight: %ld\n", brightness);
+
+	actual_brightness = backlight_get_actual_brightness(backlight);
+	printf("Hardware backlight: %ld\n", actual_brightness);
+
+	printf("normalized current brightness: %d\n",
+	       get_normalized_backlight(backlight));
+
+	/* denormalized value */
+	new_blight = (blight * max_brightness) / 255;
+
+	backlight_set_brightness(backlight, new_blight);
+	printf("Setting brightness to: %ld (norm: %d)\n", new_blight, blight);
+
+	backlight_destroy(backlight);
+}
+
+int
+main(int argc, char **argv)
+{
+	int blight, connector_id;
+	const char *default_seat = "seat0";
+	const char *path, *device_seat;
+	struct udev *udev;
+	struct udev_enumerate *e;
+	struct udev_list_entry *entry;
+	struct udev_device *device, *drm_device;
+
+	if (argc < 3) {
+		printf("Please add connector_id and brightness values from 0-255\n");
+		return 1;
+	}
+
+	connector_id = atoi(argv[1]);
+	blight = atoi(argv[2]);
+
+	udev = udev_new();
+	if (udev == NULL) {
+		printf("failed to initialize udev context\n");
+		return 1;
+	}
+
+	e = udev_enumerate_new(udev);
+	udev_enumerate_add_match_subsystem(e, "drm");
+	udev_enumerate_add_match_sysname(e, "card[0-9]*");
+
+	udev_enumerate_scan_devices(e);
+	drm_device = NULL;
+	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
+		path = udev_list_entry_get_name(entry);
+		device = udev_device_new_from_syspath(udev, path);
+		device_seat =
+			udev_device_get_property_value(device, "ID_SEAT");
+		if (!device_seat)
+			device_seat = default_seat;
+
+		drm_device = device;
+		break;
+	}
+
+	if (drm_device == NULL) {
+		printf("no drm device found\n");
+		return 1;
+	}
+
+	set_backlight(drm_device, connector_id, blight);
+
+	udev_device_unref(drm_device);
+	return 0;
+}