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-rw-r--r--sensors/akm8963.c683
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,
+};
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 17:41:33 +0000