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-rw-r--r--sensors/gp2a_light.c239
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,
+};