diff options
Diffstat (limited to 'sensors/akm8963.c')
-rw-r--r-- | sensors/akm8963.c | 683 |
1 files changed, 683 insertions, 0 deletions
diff --git a/sensors/akm8963.c b/sensors/akm8963.c new file mode 100644 index 0000000..96d35ca --- /dev/null +++ b/sensors/akm8963.c @@ -0,0 +1,683 @@ +/* + * Copyright (C) 2014 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 <hardware/sensors.h> +#include <hardware/hardware.h> + +#define LOG_TAG "smdk4x12_sensors" +#include <utils/Log.h> + +#include "smdk4x12_sensors.h" +#include "ssp.h" + +#define AKM8963_CONFIG_PATH "/data/misc/akmd_set.txt" + +struct akm8963_data { + struct smdk4x12_sensors_handlers *orientation_sensor; + + sensors_vec_t magnetic; + unsigned short magnetic_data[4][3]; + int magnetic_data_count; + int magnetic_data_index; + + unsigned short magnetic_extrema[2][3]; + unsigned char asa[3]; + int ho[3]; + + long int delay; + int device_fd; + int uinput_fd; + + pthread_t thread; + pthread_mutex_t mutex; + int thread_continue; +}; + +// This AKM8963 implementation is based on intuitive understanding of how the +// AKM8963 data is translated to SI units. +// +// The raw data is a two-byte short value that is the 16 bit ADC read value. +// This value has to be corrected using the ASA Sensivity Adujstment value +// as such: v_adj = v * (((ASA - 128) * 0.5) / 128 + 1) +// LSB values can then be converted to uT units, with 0.15uT/LSB: +// m = 0.15 * v * (((ASA - 128) * 0.5) / 128 + 1) +// +// Moreover, we calculate and apply a software offset (HO) in order to have the +// maximum final values for each axis at ~45uT and minimum at ~-45uT. +// In order to store HO as an integer, the applied offset is 0.06 * HO: +// m = 0.15 * v * (((ASA - 128) * 0.5) / 128 + 1) - 0.06 * HO + + +int akm8963_magnetic_extrema(struct akm8963_data *data, int index) +{ + if (data == NULL || index < 0 || index >= 3) + return -EINVAL; + + // Calculate the extrema from HO (software offset) + data->magnetic_extrema[0][index] = (unsigned short) ((-45.0f + 0.06 * data->ho[index]) / (0.15f * (((data->asa[index] - 128) * 0.5f) / 128 + 1))); + data->magnetic_extrema[1][index] = (unsigned short) ((45.0f + 0.06 * data->ho[index]) / (0.15f * (((data->asa[index] - 128) * 0.5f) / 128 + 1))); + + return 0; +} + +int akm8963_config_read(struct akm8963_data *data) +{ + char buffer[256] = { 0 }; + int config_fd = -1; + int offset = 0; + int length; + int count; + int value; + char *p; + int rc; + + if (data == NULL) + return -EINVAL; + + config_fd = open(AKM8963_CONFIG_PATH, O_RDONLY); + if (config_fd < 0) { + ALOGE("%s: Unable to open akm8963 config %d %s", __func__, errno, strerror(errno)); + goto error; + } + + rc = 0; + + do { + lseek(config_fd, offset, SEEK_SET); + + length = read(config_fd, buffer, sizeof(buffer)); + if (length <= 0) + break; + + p = strchr((const char *) &buffer, '\n'); + if (p != NULL) { + offset += (int) p - (int) buffer + 1; + *p = '\0'; + } else if ((size_t) length < sizeof(buffer)) { + buffer[length] = '\0'; + } + + count = sscanf((char const *) &buffer, "HSUC_HO_FORM0.x = %d", &value); + if (count == 1) { + data->ho[0] = value; + rc |= akm8963_magnetic_extrema(data, 0); + } + + count = sscanf((char const *) &buffer, "HSUC_HO_FORM0.y = %d", &value); + if (count == 1) { + data->ho[1] = value; + rc |= akm8963_magnetic_extrema(data, 1); + } + + count = sscanf((char const *) &buffer, "HSUC_HO_FORM0.z = %d", &value); + if (count == 1) { + data->ho[2] = value; + rc |= akm8963_magnetic_extrema(data, 2); + } + } while (p != NULL && length > 0); + + goto complete; + +error: + rc = -1; + +complete: + if (config_fd >= 0) + close(config_fd); + + return rc; +} + +int akm8963_config_write(struct akm8963_data *data) +{ + char buffer[256] = { 0 }; + int config_fd = -1; + int length; + int value; + int rc; + + if (data == NULL) + return -EINVAL; + + config_fd = open(AKM8963_CONFIG_PATH, O_WRONLY | O_TRUNC | O_CREAT, 0664); + if (config_fd < 0) { + ALOGE("%s: Unable to open akm8963 config", __func__); + goto error; + } + + value = (int) data->ho[0]; + length = snprintf((char *) &buffer, sizeof(buffer), "HSUC_HO_FORM0.x = %d\n", value); + + rc = write(config_fd, buffer, length); + if (rc < length) { + ALOGE("%s: Unable to write akm8963 config", __func__); + goto error; + } + + value = (int) data->ho[1]; + length = snprintf((char *) &buffer, sizeof(buffer), "HSUC_HO_FORM0.y = %d\n", value); + + rc = write(config_fd, buffer, length); + if (rc < length) { + ALOGE("%s: Unable to write akm8963 config", __func__); + goto error; + } + + value = (int) data->ho[2]; + length = snprintf((char *) &buffer, sizeof(buffer), "HSUC_HO_FORM0.z = %d\n", value); + + rc = write(config_fd, buffer, length); + if (rc < length) { + ALOGE("%s: Unable to write akm8963 config", __func__); + goto error; + } + + rc = 0; + goto complete; + +error: + rc = -1; + +complete: + if (config_fd >= 0) + close(config_fd); + + return rc; +} + +int akm8963_ho_calibration(struct akm8963_data *data, + unsigned short *magnetic_data, size_t magnetic_data_size) +{ + float ho[2]; + int gain_index; + int i; + + if (data == NULL || magnetic_data == NULL || magnetic_data_size < 3) + return -EINVAL; + + // Update the extrema from the current raw magnetic data + for (i = 0; i < 3; i++) { + if (magnetic_data[i] < data->magnetic_extrema[0][i] || data->magnetic_extrema[0][i] == 0) + data->magnetic_extrema[0][i] = magnetic_data[i]; + if (magnetic_data[i] > data->magnetic_extrema[1][i] || data->magnetic_extrema[1][i] == 0) + data->magnetic_extrema[1][i] = magnetic_data[i]; + } + + // Calculate HO (software offset) + if (data->magnetic_data_count % 10 == 0) { + for (i = 0; i < 3; i++) { + // Calculate offset for minimum to be at -45uT + ho[0] = (0.15f * (((data->asa[i] - 128) * 0.5f) / 128 + 1) * data->magnetic_extrema[0][i] + 45.0f) / 0.06f; + // Calculate offset for maximum to be at +45uT + ho[1] = (0.15f * (((data->asa[i] - 128) * 0.5f) / 128 + 1) * data->magnetic_extrema[1][i] - 45.0f) / 0.06f; + // Average offset to make everyone (mostly) happy + data->ho[i] = (int) (ho[0] + ho[1]) / 2.0f; + } + } + + return 0; +} + +int akm8963_magnetic_axis(struct akm8963_data *data, int index, float *axis) +{ + float value; + int count; + int i; + + if (data == NULL || axis == NULL || index < 0 || index >= 3) + return -EINVAL; + + count = data->magnetic_data_count >= 4 ? 4 : data->magnetic_data_count; + value = 0; + + // Average the last 4 (or less) raw magnetic values + for (i = 0; i < count; i++) + value += (float) data->magnetic_data[i][index]; + value /= count; + + // Adjust sensitivity using ASA value + value *= (((data->asa[index] - 128) * 0.5f) / 128 + 1); + + // Magnetic field value in uT from corrected value and HO offset + *axis = 0.15f * value - 0.06f * data->ho[index]; + + return 0; +} + +int akm8963_magnetic(struct akm8963_data *data) +{ + int rc; + + if (data == NULL) + return -EINVAL; + + rc = 0; + rc |= akm8963_magnetic_axis(data, 0, &data->magnetic.x); + rc |= akm8963_magnetic_axis(data, 1, &data->magnetic.y); + rc |= akm8963_magnetic_axis(data, 2, &data->magnetic.z); + + return rc; +} + +void *akm8963_thread(void *thread_data) +{ + struct smdk4x12_sensors_handlers *handlers = NULL; + struct akm8963_data *data = NULL; + struct input_event event; + struct timeval time; + unsigned char i2c_data[8] = { 0 }; + unsigned short magnetic_data[3] = { 0 }; + int index; + long int before, after; + int diff; + int device_fd; + int uinput_fd; + int rc; + + if (thread_data == NULL) + return NULL; + + handlers = (struct smdk4x12_sensors_handlers *) thread_data; + if (handlers->data == NULL) + return NULL; + + data = (struct akm8963_data *) handlers->data; + + device_fd = data->device_fd; + if (device_fd < 0) + return NULL; + + uinput_fd = data->uinput_fd; + if (uinput_fd < 0) + return NULL; + + while (data->thread_continue) { + pthread_mutex_lock(&data->mutex); + if (!data->thread_continue) + break; + + while (handlers->activated) { + gettimeofday(&time, NULL); + before = timestamp(&time); + + memset(&i2c_data, 0, sizeof(i2c_data)); + rc = ioctl(device_fd, ECS_IOCTL_GET_MAGDATA, &i2c_data); + if (rc < 0) { + ALOGE("%s: Unable to get akm8963 data", __func__); + goto next; + } + + if (!(i2c_data[0] & 0x01)) { + ALOGE("%s: akm8963 data is not ready", __func__); + goto next; + } + + magnetic_data[0] = (unsigned short) ((i2c_data[2] << 8) | (i2c_data[1] & 0xff)); + magnetic_data[1] = (unsigned short) ((i2c_data[4] << 8) | (i2c_data[3] & 0xff)); + magnetic_data[2] = (unsigned short) ((i2c_data[6] << 8) | (i2c_data[5] & 0xff)); + + index = data->magnetic_data_index; + + data->magnetic_data[index][0] = magnetic_data[0]; + data->magnetic_data[index][1] = magnetic_data[1]; + data->magnetic_data[index][2] = magnetic_data[2]; + + data->magnetic_data_index = (index + 1) % 4; + data->magnetic_data_count++; + + rc = akm8963_ho_calibration(data, (unsigned short *) &magnetic_data, sizeof(magnetic_data)); + if (rc < 0) { + ALOGE("%s: Unable to calibrate akm8963 HO", __func__); + goto next; + } + + rc = akm8963_magnetic(data); + if (rc < 0) { + ALOGE("%s: Unable to get akm8963 magnetic", __func__); + goto next; + } + + input_event_set(&event, EV_REL, REL_X, (int) (data->magnetic.x * 1000)); + write(uinput_fd, &event, sizeof(event)); + input_event_set(&event, EV_REL, REL_Y, (int) (data->magnetic.y * 1000)); + write(uinput_fd, &event, sizeof(event)); + input_event_set(&event, EV_REL, REL_Z, (int) (data->magnetic.z * 1000)); + write(uinput_fd, &event, sizeof(event)); + input_event_set(&event, EV_SYN, 0, 0); + write(uinput_fd, &event, sizeof(event)); + +next: + gettimeofday(&time, NULL); + after = timestamp(&time); + + diff = (int) (data->delay - (after - before)) / 1000; + if (diff <= 0) + continue; + + usleep(diff); + } + } + return NULL; +} + +int akm8963_init(struct smdk4x12_sensors_handlers *handlers, + struct smdk4x12_sensors_device *device) +{ + struct akm8963_data *data = NULL; + pthread_attr_t thread_attr; + int device_fd = -1; + int uinput_fd = -1; + int input_fd = -1; + int rc; + int i; + + ALOGD("%s(%p, %p)", __func__, handlers, device); + + if (handlers == NULL || device == NULL) + return -EINVAL; + + data = (struct akm8963_data *) calloc(1, sizeof(struct akm8963_data)); + + for (i = 0; i < device->handlers_count; i++) { + if (device->handlers[i] == NULL) + continue; + + if (device->handlers[i]->handle == SENSOR_TYPE_ORIENTATION) + data->orientation_sensor = device->handlers[i]; + } + + device_fd = open("/dev/akm8963", O_RDONLY); + if (device_fd < 0) { + ALOGE("%s: Unable to open device", __func__); + goto error; + } + + rc = ioctl(device_fd, ECS_IOCTL_GET_FUSEROMDATA, &data->asa); + if (rc < 0) { + ALOGE("%s: Unable to get akm8963 FUSE ROM data", __func__); + goto error; + } + + ALOGD("AKM8963 ASA (Sensitivity Adjustment) values are: (%d, %d, %d)", + data->asa[0], data->asa[1], data->asa[2]); + + uinput_fd = uinput_rel_create("magnetic"); + if (uinput_fd < 0) { + ALOGD("%s: Unable to create uinput", __func__); + goto error; + } + + input_fd = input_open("magnetic"); + if (input_fd < 0) { + ALOGE("%s: Unable to open magnetic input", __func__); + goto error; + } + + data->thread_continue = 1; + + pthread_mutex_init(&data->mutex, NULL); + pthread_mutex_lock(&data->mutex); + + pthread_attr_init(&thread_attr); + pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); + + rc = pthread_create(&data->thread, &thread_attr, akm8963_thread, (void *) handlers); + if (rc < 0) { + ALOGE("%s: Unable to create akm8963 thread", __func__); + pthread_mutex_destroy(&data->mutex); + goto error; + } + + data->device_fd = device_fd; + data->uinput_fd = uinput_fd; + handlers->poll_fd = input_fd; + handlers->data = (void *) data; + + return 0; + +error: + if (data != NULL) + free(data); + + if (uinput_fd >= 0) + close(uinput_fd); + + if (input_fd >= 0) + close(input_fd); + + if (device_fd >= 0) + close(device_fd); + + handlers->poll_fd = -1; + handlers->data = NULL; + + return -1; +} + +int akm8963_deinit(struct smdk4x12_sensors_handlers *handlers) +{ + struct akm8963_data *data = NULL; + int rc; + + ALOGD("%s(%p)", __func__, handlers); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct akm8963_data *) handlers->data; + + handlers->activated = 0; + data->thread_continue = 0; + pthread_mutex_unlock(&data->mutex); + + pthread_mutex_destroy(&data->mutex); + + if (data->uinput_fd >= 0) { + uinput_destroy(data->uinput_fd); + close(data->uinput_fd); + } + data->uinput_fd = -1; + + if (handlers->poll_fd >= 0) + close(handlers->poll_fd); + handlers->poll_fd = -1; + + if (data->device_fd >= 0) + close(data->device_fd); + data->device_fd = -1; + + free(handlers->data); + handlers->data = NULL; + + return 0; +} + +int akm8963_activate(struct smdk4x12_sensors_handlers *handlers) +{ + struct akm8963_data *data; + int rc; + + ALOGD("%s(%p)", __func__, handlers); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct akm8963_data *) handlers->data; + + rc = akm8963_config_read(data); + if (rc < 0) { + ALOGE("%s: Unable to read akm8963 config", __func__); + } + + rc = ssp_sensor_enable(GEOMAGNETIC_SENSOR); + if (rc < 0) { + ALOGE("%s: Unable to enable ssp sensor", __func__); + return -1; + } + + handlers->activated = 1; + pthread_mutex_unlock(&data->mutex); + + return 0; +} + +int akm8963_deactivate(struct smdk4x12_sensors_handlers *handlers) +{ + struct akm8963_data *data; + int empty; + int rc; + int i; + + ALOGD("%s(%p)", __func__, handlers); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct akm8963_data *) handlers->data; + + empty = 1; + + for (i = 0; i < (ssize_t) (sizeof(data->magnetic_extrema) / (sizeof(short) * 2)); i++) { + if (data->magnetic_extrema[0][i] != 0 || data->magnetic_extrema[1][i] != 0) { + empty = 0; + break; + } + } + + if (!empty) { + rc = akm8963_config_write(data); + if (rc < 0) + ALOGE("%s: Unable to write akm8963 config", __func__); + } + + rc = ssp_sensor_disable(GEOMAGNETIC_SENSOR); + if (rc < 0) { + ALOGE("%s: Unable to disable ssp sensor", __func__); + return -1; + } + + handlers->activated = 0; + + return 0; +} + +int akm8963_set_delay(struct smdk4x12_sensors_handlers *handlers, long int delay) +{ + struct akm8963_data *data; + char path_delay[PATH_MAX] = "/sys/class/sensors/ssp_sensor/mag_poll_delay"; + int rc; + + ALOGD("%s(%p, %ld)", __func__, handlers, delay); + + if (handlers == NULL || handlers->data == NULL) + return -EINVAL; + + data = (struct akm8963_data *) handlers->data; + + rc = sysfs_value_write(path_delay, (int) delay); + if (rc < 0) { + ALOGE("%s: Unable to write sysfs value", __func__); + return -1; + } + + data->delay = delay; + + return 0; +} + +float akm8963_convert(int value) +{ + return (float) value / 1000.0f; +} + +int akm8963_get_data(struct smdk4x12_sensors_handlers *handlers, + struct sensors_event_t *event) +{ + struct akm8963_data *data; + struct input_event input_event; + int input_fd; + int rc; + +// ALOGD("%s(%p, %p)", __func__, handlers, event); + + if (handlers == NULL || handlers->data == NULL || event == NULL) + return -EINVAL; + + data = (struct akm8963_data *) handlers->data; + + input_fd = handlers->poll_fd; + if (input_fd < 0) + return -1; + + memset(event, 0, sizeof(struct sensors_event_t)); + event->version = sizeof(struct sensors_event_t); + event->sensor = handlers->handle; + event->type = handlers->handle; + + event->magnetic.status = SENSOR_STATUS_ACCURACY_MEDIUM; + + 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_X: + event->magnetic.x = akm8963_convert(input_event.value); + break; + case REL_Y: + event->magnetic.y = akm8963_convert(input_event.value); + break; + case REL_Z: + event->magnetic.z = akm8963_convert(input_event.value); + break; + default: + continue; + } + } 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); + + if (data->orientation_sensor != NULL) + orientation_fill(data->orientation_sensor, NULL, &event->magnetic); + + return 0; +} + +struct smdk4x12_sensors_handlers akm8963 = { + .name = "AKM8963", + .handle = SENSOR_TYPE_MAGNETIC_FIELD, + .init = akm8963_init, + .deinit = akm8963_deinit, + .activate = akm8963_activate, + .deactivate = akm8963_deactivate, + .set_delay = akm8963_set_delay, + .get_data = akm8963_get_data, + .activated = 0, + .needed = 0, + .poll_fd = -1, + .data = NULL, +}; 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