diff options
Diffstat (limited to 'sensors/bmp180.c')
| -rw-r--r-- | sensors/bmp180.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/sensors/bmp180.c b/sensors/bmp180.c new file mode 100644 index 0000000..c50474c --- /dev/null +++ b/sensors/bmp180.c @@ -0,0 +1,238 @@ +/* + * 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 "smdk4x12_sensors" +#include <utils/Log.h> + +#include "smdk4x12_sensors.h" +#include "ssp.h" + +struct bmp180_data { + char path_delay[PATH_MAX]; +}; + +int bmp180_init(struct smdk4x12_sensors_handlers *handlers, + struct smdk4x12_sensors_device *device) +{ + struct bmp180_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 bmp180_data *) calloc(1, sizeof(struct bmp180_data)); + + input_fd = input_open("pressure_sensor"); + if (input_fd < 0) { + ALOGE("%s: Unable to open input", __func__); + goto error; + } + + rc = sysfs_path_prefix("pressure_sensor", (char *) &path); + if (rc < 0 || path[0] == '\0') { + ALOGE("%s: Unable to open sysfs", __func__); + goto error; + } + + snprintf(data->path_delay, PATH_MAX, "%s/pressure_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 bmp180_deinit(struct smdk4x12_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 bmp180_activate(struct smdk4x12_sensors_handlers *handlers) +{ + struct bmp180_data *data; + int rc; + + ALOGD("%s(%p)", __func__, handlers); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct bmp180_data *) handlers->data; + + rc = ssp_sensor_enable(PRESSURE_SENSOR); + if (rc < 0) { + ALOGE("%s: Unable to enable ssp sensor", __func__); + return -1; + } + + handlers->activated = 1; + + return 0; +} + +int bmp180_deactivate(struct smdk4x12_sensors_handlers *handlers) +{ + struct bmp180_data *data; + int rc; + + ALOGD("%s(%p)", __func__, handlers); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct bmp180_data *) handlers->data; + + rc = ssp_sensor_disable(PRESSURE_SENSOR); + if (rc < 0) { + ALOGE("%s: Unable to disable ssp sensor", __func__); + return -1; + } + + handlers->activated = 1; + + return 0; +} + +int bmp180_set_delay(struct smdk4x12_sensors_handlers *handlers, long int delay) +{ + struct bmp180_data *data; + int rc; + + ALOGD("%s(%p, %ld)", __func__, handlers, delay); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct bmp180_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 bmp180_convert(int value) +{ + return value / 100.0f; +} + +int bmp180_get_data(struct smdk4x12_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_REL) { + switch (input_event.code) { + case REL_HWHEEL: + event->pressure = bmp180_convert(input_event.value); + break; + default: + continue; + } + } else if (input_event.type == EV_SYN) { + if (input_event.code == SYN_REPORT && event->pressure != 0) { + event->timestamp = input_timestamp(&input_event); + break; + } else { + return -1; + } + } + } while (1); + + return 0; +} + +struct smdk4x12_sensors_handlers bmp180 = { + .name = "BMP180", + .handle = SENSOR_TYPE_PRESSURE, + .init = bmp180_init, + .deinit = bmp180_deinit, + .activate = bmp180_activate, + .deactivate = bmp180_deactivate, + .set_delay = bmp180_set_delay, + .get_data = bmp180_get_data, + .activated = 0, + .needed = 0, + .poll_fd = -1, + .data = NULL, +}; |