1 files changed, 239 insertions, 0 deletions
diff --git a/sensors/gp2a_light.c b/sensors/gp2a_light.c
new file mode 100644
index 0000000..a76d8e9
--- /dev/null
+++ b/sensors/gp2a_light.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2013 Paul Kocialkowski <contact@paulk.fr>
+ *
+ * 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 3 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <math.h>
+#include <sys/types.h>
+#include <linux/ioctl.h>
+#include <linux/input.h>
+
+#include <hardware/sensors.h>
+#include <hardware/hardware.h>
+
+#define LOG_TAG "aries_sensors"
+#include <utils/Log.h>
+
+#include "aries_sensors.h"
+
+struct gp2a_light_data {
+	char path_enable[PATH_MAX];
+	char path_delay[PATH_MAX];
+};
+
+int gp2a_light_init(struct aries_sensors_handlers *handlers,
+	struct aries_sensors_device *device)
+{
+	struct gp2a_light_data *data = NULL;
+	char path[PATH_MAX] = { 0 };
+	int input_fd = -1;
+	int rc;
+
+	ALOGD("%s(%p, %p)", __func__, handlers, device);
+
+	if (handlers == NULL)
+		return -EINVAL;
+
+	data = (struct gp2a_light_data *) calloc(1, sizeof(struct gp2a_light_data));
+
+	input_fd = input_open("lightsensor-level");
+	if (input_fd < 0) {
+		ALOGE("%s: Unable to open input", __func__);
+		goto error;
+	}
+
+	rc = sysfs_path_prefix("lightsensor-level", (char *) &path);
+	if (rc < 0 || path[0] == '\0') {
+		ALOGE("%s: Unable to open sysfs", __func__);
+		goto error;
+	}
+
+	snprintf(data->path_enable, PATH_MAX, "%s/enable", path);
+	snprintf(data->path_delay, PATH_MAX, "%s/poll_delay", path);
+
+	handlers->poll_fd = input_fd;
+	handlers->data = (void *) data;
+
+	return 0;
+
+error:
+	if (data != NULL)
+		free(data);
+
+	if (input_fd >= 0)
+		close(input_fd);
+
+	handlers->poll_fd = -1;
+	handlers->data = NULL;
+
+	return -1;
+}
+
+int gp2a_light_deinit(struct aries_sensors_handlers *handlers)
+{
+	ALOGD("%s(%p)", __func__, handlers);
+
+	if (handlers == NULL)
+		return -EINVAL;
+
+	if (handlers->poll_fd >= 0)
+		close(handlers->poll_fd);
+	handlers->poll_fd = -1;
+
+	if (handlers->data != NULL)
+		free(handlers->data);
+	handlers->data = NULL;
+
+	return 0;
+}
+
+int gp2a_light_activate(struct aries_sensors_handlers *handlers)
+{
+	struct gp2a_light_data *data;
+	int rc;
+
+	ALOGD("%s(%p)", __func__, handlers);
+
+	if (handlers == NULL || handlers->data == NULL)
+		return -EINVAL;
+
+	data = (struct gp2a_light_data *) handlers->data;
+
+	rc = sysfs_value_write(data->path_enable, 1);
+	if (rc < 0) {
+		ALOGE("%s: Unable to write sysfs value", __func__);
+		return -1;
+	}
+
+	handlers->activated = 1;
+
+	return 0;
+}
+
+int gp2a_light_deactivate(struct aries_sensors_handlers *handlers)
+{
+	struct gp2a_light_data *data;
+	int rc;
+
+	ALOGD("%s(%p)", __func__, handlers);
+
+	if (handlers == NULL || handlers->data == NULL)
+		return -EINVAL;
+
+	data = (struct gp2a_light_data *) handlers->data;
+
+	rc = sysfs_value_write(data->path_enable, 0);
+	if (rc < 0) {
+		ALOGE("%s: Unable to write sysfs value", __func__);
+		return -1;
+	}
+
+	handlers->activated = 1;
+
+	return 0;
+}
+
+int gp2a_light_set_delay(struct aries_sensors_handlers *handlers, long int delay)
+{
+	struct gp2a_light_data *data;
+	int rc;
+
+	ALOGD("%s(%p, %ld)", __func__, handlers, delay);
+
+	if (handlers == NULL || handlers->data == NULL)
+		return -EINVAL;
+
+	data = (struct gp2a_light_data *) handlers->data;
+
+	rc = sysfs_value_write(data->path_delay, (int) delay);
+	if (rc < 0) {
+		ALOGE("%s: Unable to write sysfs value", __func__);
+		return -1;
+	}
+
+	return 0;
+}
+
+float gp2a_light_convert(int value)
+{
+	// Converting the raw value to lux units is done with:
+	// I = 10 * log(light) uA
+	// U = raw * 3300 / 4095 (max ADC value is 3.3V for 4095 LSB)
+	// R = 47kOhm
+	// => light = 10 ^ (I / 10) = 10 ^ (U / R / 10)
+	// => light = 10 ^ (raw * 330 / 4095 / 47)
+	// Only 1/4 of light reaches the sensor:
+	// => light = 4 * (10 ^ (raw * 330 / 4095 / 47))
+
+	return powf(10, value * (330.0f / 4095.0f / 47.0f)) * 4;
+}
+
+int gp2a_light_get_data(struct aries_sensors_handlers *handlers,
+	struct sensors_event_t *event)
+{
+	struct input_event input_event;
+	int input_fd;
+	int rc;
+
+//	ALOGD("%s(%p, %p)", __func__, handlers, event);
+
+	if (handlers == NULL || event == NULL)
+		return -EINVAL;
+
+	input_fd = handlers->poll_fd;
+	if (input_fd < 0)
+		return -EINVAL;
+
+	memset(event, 0, sizeof(struct sensors_event_t));
+	event->version = sizeof(struct sensors_event_t);
+	event->sensor = handlers->handle;
+	event->type = handlers->handle;
+
+	do {
+		rc = read(input_fd, &input_event, sizeof(input_event));
+		if (rc < (int) sizeof(input_event))
+			break;
+
+		if (input_event.type == EV_ABS) {
+			if (input_event.code == ABS_MISC)
+				event->light = gp2a_light_convert(input_event.value);
+		} else if (input_event.type == EV_SYN) {
+			if (input_event.code == SYN_REPORT)
+				event->timestamp = input_timestamp(&input_event);
+		}
+	} while (input_event.type != EV_SYN);
+
+	return 0;
+}
+
+struct aries_sensors_handlers gp2a_light = {
+	.name = "GP2A Light",
+	.handle = SENSOR_TYPE_LIGHT,
+	.init = gp2a_light_init,
+	.deinit = gp2a_light_deinit,
+	.activate = gp2a_light_activate,
+	.deactivate = gp2a_light_deactivate,
+	.set_delay = gp2a_light_set_delay,
+	.get_data = gp2a_light_get_data,
+	.activated = 0,
+	.needed = 0,
+	.poll_fd = -1,
+	.data = NULL,
+};