From cd039f42550bc16289c9ccb80cefdec84408d8a6 Mon Sep 17 00:00:00 2001 From: Paul Kocialkowski Date: Mon, 23 Dec 2013 22:25:33 +0100 Subject: Aries Sensors Signed-off-by: Paul Kocialkowski --- sensors/gp2a_light.c | 239 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 239 insertions(+) create mode 100644 sensors/gp2a_light.c (limited to 'sensors/gp2a_light.c') 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 + * + * 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 . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define LOG_TAG "aries_sensors" +#include + +#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, +}; -- cgit v1.1