diff options
Diffstat (limited to 'libsensors_iio/software/core/HAL/linux/inv_sysfs_utils.c')
| -rw-r--r-- | libsensors_iio/software/core/HAL/linux/inv_sysfs_utils.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/libsensors_iio/software/core/HAL/linux/inv_sysfs_utils.c b/libsensors_iio/software/core/HAL/linux/inv_sysfs_utils.c new file mode 100644 index 0000000..c45badd --- /dev/null +++ b/libsensors_iio/software/core/HAL/linux/inv_sysfs_utils.c @@ -0,0 +1,317 @@ +/** + * @brief Provides helpful file IO wrappers for use with sysfs. + * @details Based on Jonathan Cameron's @e iio_utils.h. + */ + +#include <string.h> +#include <stdlib.h> +#include <ctype.h> +#include <stdio.h> +#include <stdint.h> +#include <dirent.h> +#include <errno.h> +#include <unistd.h> +#include "inv_sysfs_utils.h" + +/* General TODO list: + * Select more reasonable string lengths or use fseek and malloc. + */ + +/** + * inv_sysfs_write() - Write an integer to a file. + * @filename: Path to file. + * @data: Value to write to file. + * Returns number of bytes written or a negative error code. + */ +int inv_sysfs_write(char *filename, long data) +{ + FILE *fp; + int count; + + if (!filename) + return -1; + fp = fopen(filename, "w"); + if (!fp) + return -errno; + count = fprintf(fp, "%ld", data); + fclose(fp); + return count; +} + +/** + * inv_sysfs_read() - Read a string from a file. + * @filename: Path to file. + * @num_bytes: Number of bytes to read. + * @data: Data from file. + * Returns number of bytes written or a negative error code. + */ +int inv_sysfs_read(char *filename, long num_bytes, char *data) +{ + FILE *fp; + int count; + + if (!filename) + return -1; + fp = fopen(filename, "r"); + if (!fp) + return -errno; + count = fread(data, 1, num_bytes, fp); + fclose(fp); + return count; +} + +/** + * inv_read_buffer() - Read data from ring buffer. + * @fd: File descriptor for buffer file. + * @data: Data in hardware units. + * @timestamp: Time when data was read from device. Use NULL if unsupported. + * Returns number of bytes written or a negative error code. + */ +int inv_read_buffer(int fd, long *data, long long *timestamp) +{ + char str[35]; + int count; + + count = read(fd, str, sizeof(str)); + if (!count) + return count; + if (!timestamp) + count = sscanf(str, "%ld%ld%ld", &data[0], &data[1], &data[2]); + else + count = sscanf(str, "%ld%ld%ld%lld", &data[0], &data[1], + &data[2], timestamp); + + if (count < (timestamp?4:3)) + return -EAGAIN; + return count; +} + +/** + * inv_read_raw() - Read raw data. + * @names: Names of sysfs files. + * @data: Data in hardware units. + * @timestamp: Time when data was read from device. Use NULL if unsupported. + * Returns number of bytes written or a negative error code. + */ +int inv_read_raw(const struct inv_sysfs_names_s *names, long *data, + long long *timestamp) +{ + char str[40]; + int count; + + count = inv_sysfs_read((char*)names->raw_data, sizeof(str), str); + if (count < 0) + return count; + if (!timestamp) + count = sscanf(str, "%ld%ld%ld", &data[0], &data[1], &data[2]); + else + count = sscanf(str, "%ld%ld%ld%lld", &data[0], &data[1], + &data[2], timestamp); + if (count < (timestamp?4:3)) + return -EAGAIN; + return count; +} + +/** + * inv_read_temperature_raw() - Read temperature. + * @names: Names of sysfs files. + * @data: Data in hardware units. + * @timestamp: Time when data was read from device. + * Returns number of bytes written or a negative error code. + */ +int inv_read_temperature_raw(const struct inv_sysfs_names_s *names, short *data, + long long *timestamp) +{ + char str[25]; + int count; + + count = inv_sysfs_read((char*)names->temperature, sizeof(str), str); + if (count < 0) + return count; + count = sscanf(str, "%hd%lld", &data[0], timestamp); + if (count < 2) + return -EAGAIN; + return count; +} + +/** + * inv_read_fifo_rate() - Read fifo rate. + * @names: Names of sysfs files. + * @data: Fifo rate. + * Returns number of bytes written or a negative error code. + */ +int inv_read_fifo_rate(const struct inv_sysfs_names_s *names, short *data) +{ + char str[8]; + int count; + + count = inv_sysfs_read((char*)names->fifo_rate, sizeof(str), str); + if (count < 0) + return count; + count = sscanf(str, "%hd", data); + if (count < 1) + return -EAGAIN; + return count; +} + +/** + * inv_read_power_state() - Read power state. + * @names: Names of sysfs files. + * @data: 1 if device is on. + * Returns number of bytes written or a negative error code. + */ +int inv_read_power_state(const struct inv_sysfs_names_s *names, char *data) +{ + char str[2]; + int count; + + count = inv_sysfs_read((char*)names->power_state, sizeof(str), str); + if (count < 0) + return count; + count = sscanf(str, "%hd", (short*)data); + if (count < 1) + return -EAGAIN; + return count; +} + +/** + * inv_read_scale() - Read scale. + * @names: Names of sysfs files. + * @data: 1 if device is on. + * Returns number of bytes written or a negative error code. + */ +int inv_read_scale(const struct inv_sysfs_names_s *names, float *data) +{ + char str[5]; + int count; + + count = inv_sysfs_read((char*)names->scale, sizeof(str), str); + if (count < 0) + return count; + count = sscanf(str, "%f", data); + if (count < 1) + return -EAGAIN; + return count; +} + +/** + * inv_read_temp_scale() - Read temperature scale. + * @names: Names of sysfs files. + * @data: 1 if device is on. + * Returns number of bytes written or a negative error code. + */ +int inv_read_temp_scale(const struct inv_sysfs_names_s *names, short *data) +{ + char str[4]; + int count; + + count = inv_sysfs_read((char*)names->temp_scale, sizeof(str), str); + if (count < 0) + return count; + count = sscanf(str, "%hd", data); + if (count < 1) + return -EAGAIN; + return count; +} + +/** + * inv_read_temp_offset() - Read temperature offset. + * @names: Names of sysfs files. + * @data: 1 if device is on. + * Returns number of bytes written or a negative error code. + */ +int inv_read_temp_offset(const struct inv_sysfs_names_s *names, short *data) +{ + char str[4]; + int count; + + count = inv_sysfs_read((char*)names->temp_offset, sizeof(str), str); + if (count < 0) + return count; + count = sscanf(str, "%hd", data); + if (count < 1) + return -EAGAIN; + return count; +} + +/** + * inv_read_q16() - Get data as q16 fixed point. + * @names: Names of sysfs files. + * @data: 1 if device is on. + * @timestamp: Time when data was read from device. + * Returns number of bytes written or a negative error code. + */ +int inv_read_q16(const struct inv_sysfs_names_s *names, long *data, + long long *timestamp) +{ + int count; + short raw[3]; + float scale; + count = inv_read_raw(names, (long*)raw, timestamp); + count += inv_read_scale(names, &scale); + data[0] = (long)(raw[0] * (65536.f / scale)); + data[1] = (long)(raw[1] * (65536.f / scale)); + data[2] = (long)(raw[2] * (65536.f / scale)); + return count; +} + +/** + * inv_read_q16() - Get temperature data as q16 fixed point. + * @names: Names of sysfs files. + * @data: 1 if device is on. + * @timestamp: Time when data was read from device. + * Returns number of bytes read or a negative error code. + */ +int inv_read_temp_q16(const struct inv_sysfs_names_s *names, long *data, + long long *timestamp) +{ + int count = 0; + short raw; + static short scale, offset; + static unsigned char first_read = 1; + + if (first_read) { + count += inv_read_temp_scale(names, &scale); + count += inv_read_temp_offset(names, &offset); + first_read = 0; + } + count += inv_read_temperature_raw(names, &raw, timestamp); + data[0] = (long)((35 + ((float)(raw - offset) / scale)) * 65536.f); + + return count; +} + +/** + * inv_write_fifo_rate() - Write fifo rate. + * @names: Names of sysfs files. + * @data: Fifo rate. + * Returns number of bytes written or a negative error code. + */ +int inv_write_fifo_rate(const struct inv_sysfs_names_s *names, short data) +{ + return inv_sysfs_write((char*)names->fifo_rate, (long)data); +} + +/** + * inv_write_buffer_enable() - Enable/disable buffer in /dev. + * @names: Names of sysfs files. + * @data: Fifo rate. + * Returns number of bytes written or a negative error code. + */ +int inv_write_buffer_enable(const struct inv_sysfs_names_s *names, char data) +{ + return inv_sysfs_write((char*)names->enable, (long)data); +} + +/** + * inv_write_power_state() - Turn device on/off. + * @names: Names of sysfs files. + * @data: 1 to turn on. + * Returns number of bytes written or a negative error code. + */ +int inv_write_power_state(const struct inv_sysfs_names_s *names, char data) +{ + return inv_sysfs_write((char*)names->power_state, (long)data); +} + + |