staging: iio: Documentation: Introduce iio_utils.c (bdcb31d0) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/staging/iio/Documentation/generic_buffer.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#define _GNU_SOURCE

		#include <unistd.h>
		#include <stdlib.h>
		#include <dirent.h>
		#include <fcntl.h>
		#include <stdio.h>

drivers/staging/iio/Documentation/iio_event_monitor.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@
		#define _GNU_SOURCE

		#include <unistd.h>
		#include <stdlib.h>
		#include <stdbool.h>
		#include <stdio.h>
		#include <errno.h>

drivers/staging/iio/Documentation/iio_utils.c

0 → 100644

+651 −0

Original line number	Diff line number	Diff line
		/* IIO - useful set of util functionality
		*
		* Copyright (c) 2008 Jonathan Cameron
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms of the GNU General Public License version 2 as published by
		* the Free Software Foundation.
		*/

		#include <string.h>
		#include <stdlib.h>
		#include <stdio.h>
		#include <stdint.h>
		#include <dirent.h>
		#include <errno.h>
		#include <ctype.h>
		#include "iio_utils.h"

		const char *iio_dir = "/sys/bus/iio/devices/";

		/**
		* iioutils_break_up_name() - extract generic name from full channel name
		* @full_name: the full channel name
		* @generic_name: the output generic channel name
		**/
		int iioutils_break_up_name(const char *full_name,
		char **generic_name)
		{
		char *current;
		char w, r;
		char *working;

		current = strdup(full_name);
		working = strtok(current, "_\0");
		w = working;
		r = working;

		while (*r != '\0') {
		if (!isdigit(*r)) {
		w = r;
		w++;
		}
		r++;
		}
		*w = '\0';
		*generic_name = strdup(working);
		free(current);

		return 0;
		}

		/**
		* iioutils_get_type() - find and process _type attribute data
		* @is_signed: output whether channel is signed
		* @bytes: output how many bytes the channel storage occupies
		* @mask: output a bit mask for the raw data
		* @be: big endian
		* @device_dir: the iio device directory
		* @name: the channel name
		* @generic_name: the channel type name
		**/
		int iioutils_get_type(unsigned *is_signed,
		unsigned *bytes,
		unsigned *bits_used,
		unsigned *shift,
		uint64_t *mask,
		unsigned *be,
		const char *device_dir,
		const char *name,
		const char *generic_name)
		{
		FILE *sysfsfp;
		int ret;
		DIR *dp;
		char scan_el_dir, builtname, builtname_generic, filename = 0;
		char signchar, endianchar;
		unsigned padint;
		const struct dirent *ent;

		ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_ret;
		}
		ret = asprintf(&builtname, FORMAT_TYPE_FILE, name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_free_scan_el_dir;
		}
		ret = asprintf(&builtname_generic, FORMAT_TYPE_FILE, generic_name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_free_builtname;
		}

		dp = opendir(scan_el_dir);
		if (dp == NULL) {
		ret = -errno;
		goto error_free_builtname_generic;
		}
		while (ent = readdir(dp), ent != NULL)
		/*
		* Do we allow devices to override a generic name with
		* a specific one?
		*/
		if ((strcmp(builtname, ent->d_name) == 0) \|\|
		(strcmp(builtname_generic, ent->d_name) == 0)) {
		ret = asprintf(&filename,
		"%s/%s", scan_el_dir, ent->d_name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_closedir;
		}
		sysfsfp = fopen(filename, "r");
		if (sysfsfp == NULL) {
		printf("failed to open %s\n", filename);
		ret = -errno;
		goto error_free_filename;
		}

		ret = fscanf(sysfsfp,
		"%ce:%c%u/%u>>%u",
		&endianchar,
		&signchar,
		bits_used,
		&padint, shift);
		if (ret < 0) {
		printf("failed to pass scan type description\n");
		ret = -errno;
		goto error_close_sysfsfp;
		}
		*be = (endianchar == 'b');
		*bytes = padint / 8;
		if (*bits_used == 64)
		*mask = ~0;
		else
		mask = (1 << bits_used) - 1;
		if (signchar == 's')
		*is_signed = 1;
		else
		*is_signed = 0;
		fclose(sysfsfp);
		free(filename);

		filename = 0;
		sysfsfp = 0;
		}
		error_close_sysfsfp:
		if (sysfsfp)
		fclose(sysfsfp);
		error_free_filename:
		if (filename)
		free(filename);
		error_closedir:
		closedir(dp);
		error_free_builtname_generic:
		free(builtname_generic);
		error_free_builtname:
		free(builtname);
		error_free_scan_el_dir:
		free(scan_el_dir);
		error_ret:
		return ret;
		}

		int iioutils_get_param_float(float *output,
		const char *param_name,
		const char *device_dir,
		const char *name,
		const char *generic_name)
		{
		FILE *sysfsfp;
		int ret;
		DIR *dp;
		char builtname, builtname_generic;
		char *filename = NULL;
		const struct dirent *ent;

		ret = asprintf(&builtname, "%s_%s", name, param_name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_ret;
		}
		ret = asprintf(&builtname_generic,
		"%s_%s", generic_name, param_name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_free_builtname;
		}
		dp = opendir(device_dir);
		if (dp == NULL) {
		ret = -errno;
		goto error_free_builtname_generic;
		}
		while (ent = readdir(dp), ent != NULL)
		if ((strcmp(builtname, ent->d_name) == 0) \|\|
		(strcmp(builtname_generic, ent->d_name) == 0)) {
		ret = asprintf(&filename,
		"%s/%s", device_dir, ent->d_name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_closedir;
		}
		sysfsfp = fopen(filename, "r");
		if (!sysfsfp) {
		ret = -errno;
		goto error_free_filename;
		}
		fscanf(sysfsfp, "%f", output);
		break;
		}
		error_free_filename:
		if (filename)
		free(filename);
		error_closedir:
		closedir(dp);
		error_free_builtname_generic:
		free(builtname_generic);
		error_free_builtname:
		free(builtname);
		error_ret:
		return ret;
		}

		/**
		* bsort_channel_array_by_index() - reorder so that the array is in index order
		*
		**/

		void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
		int cnt)
		{

		struct iio_channel_info temp;
		int x, y;

		for (x = 0; x < cnt; x++)
		for (y = 0; y < (cnt - 1); y++)
		if ((ci_array)[y].index > (ci_array)[y+1].index) {
		temp = (*ci_array)[y + 1];
		(ci_array)[y + 1] = (ci_array)[y];
		(*ci_array)[y] = temp;
		}
		}

		/**
		* build_channel_array() - function to figure out what channels are present
		* @device_dir: the IIO device directory in sysfs
		* @
		**/
		int build_channel_array(const char *device_dir,
		struct iio_channel_info **ci_array,
		int *counter)
		{
		DIR *dp;
		FILE *sysfsfp;
		int count, i;
		struct iio_channel_info *current;
		int ret;
		const struct dirent *ent;
		char *scan_el_dir;
		char *filename;

		*counter = 0;
		ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_ret;
		}
		dp = opendir(scan_el_dir);
		if (dp == NULL) {
		ret = -errno;
		goto error_free_name;
		}
		while (ent = readdir(dp), ent != NULL)
		if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
		"_en") == 0) {
		ret = asprintf(&filename,
		"%s/%s", scan_el_dir, ent->d_name);
		if (ret < 0) {
		ret = -ENOMEM;
		goto error_close_dir;
		}
		sysfsfp = fopen(filename, "r");
		if (sysfsfp == NULL) {
		ret = -errno;
		free(filename);
		goto error_close_dir;
		}
		fscanf(sysfsfp, "%i", &ret);
		if (ret == 1)
		(*counter)++;
		fclose(sysfsfp);
		free(filename);
		}
		ci_array = malloc(sizeof(ci_array) (*counter));
		if (*ci_array == NULL) {
		ret = -ENOMEM;
		goto error_close_dir;
		}
		seekdir(dp, 0);
		count = 0;
		while (ent = readdir(dp), ent != NULL) {
		if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
		"_en") == 0) {
		int current_enabled = 0;

		current = &(*ci_array)[count++];
		ret = asprintf(&filename,
		"%s/%s", scan_el_dir, ent->d_name);
		if (ret < 0) {
		ret = -ENOMEM;
		/* decrement count to avoid freeing name */
		count--;
		goto error_cleanup_array;
		}
		sysfsfp = fopen(filename, "r");
		if (sysfsfp == NULL) {
		free(filename);
		ret = -errno;
		goto error_cleanup_array;
		}
		fscanf(sysfsfp, "%i", &current_enabled);
		fclose(sysfsfp);

		if (!current_enabled) {
		free(filename);
		count--;
		continue;
		}

		current->scale = 1.0;
		current->offset = 0;
		current->name = strndup(ent->d_name,
		strlen(ent->d_name) -
		strlen("_en"));
		if (current->name == NULL) {
		free(filename);
		ret = -ENOMEM;
		goto error_cleanup_array;
		}
		/* Get the generic and specific name elements */
		ret = iioutils_break_up_name(current->name,
		&current->generic_name);
		if (ret) {
		free(filename);
		goto error_cleanup_array;
		}
		ret = asprintf(&filename,
		"%s/%s_index",
		scan_el_dir,
		current->name);
		if (ret < 0) {
		free(filename);
		ret = -ENOMEM;
		goto error_cleanup_array;
		}
		sysfsfp = fopen(filename, "r");
		fscanf(sysfsfp, "%u", &current->index);
		fclose(sysfsfp);
		free(filename);
		/* Find the scale */
		ret = iioutils_get_param_float(&current->scale,
		"scale",
		device_dir,
		current->name,
		current->generic_name);
		if (ret < 0)
		goto error_cleanup_array;
		ret = iioutils_get_param_float(&current->offset,
		"offset",
		device_dir,
		current->name,
		current->generic_name);
		if (ret < 0)
		goto error_cleanup_array;
		ret = iioutils_get_type(&current->is_signed,
		&current->bytes,
		&current->bits_used,
		&current->shift,
		&current->mask,
		&current->be,
		device_dir,
		current->name,
		current->generic_name);
		}
		}

		closedir(dp);
		/* reorder so that the array is in index order */
		bsort_channel_array_by_index(ci_array, *counter);

		return 0;

		error_cleanup_array:
		for (i = count - 1; i >= 0; i--)
		free((*ci_array)[i].name);
		free(*ci_array);
		error_close_dir:
		closedir(dp);
		error_free_name:
		free(scan_el_dir);
		error_ret:
		return ret;
		}

		/**
		* find_type_by_name() - function to match top level types by name
		* @name: top level type instance name
		* @type: the type of top level instance being sort
		*
		* Typical types this is used for are device and trigger.
		**/
		int find_type_by_name(const char name, const char type)
		{
		const struct dirent *ent;
		int number, numstrlen;

		FILE *nameFile;
		DIR *dp;
		char thisname[IIO_MAX_NAME_LENGTH];
		char *filename;

		dp = opendir(iio_dir);
		if (dp == NULL) {
		printf("No industrialio devices available\n");
		return -ENODEV;
		}

		while (ent = readdir(dp), ent != NULL) {
		if (strcmp(ent->d_name, ".") != 0 &&
		strcmp(ent->d_name, "..") != 0 &&
		strlen(ent->d_name) > strlen(type) &&
		strncmp(ent->d_name, type, strlen(type)) == 0) {
		numstrlen = sscanf(ent->d_name + strlen(type),
		"%d",
		&number);
		/* verify the next character is not a colon */
		if (strncmp(ent->d_name + strlen(type) + numstrlen,
		":",
		1) != 0) {
		filename = malloc(strlen(iio_dir)
		+ strlen(type)
		+ numstrlen
		+ 6);
		if (filename == NULL) {
		closedir(dp);
		return -ENOMEM;
		}
		sprintf(filename, "%s%s%d/name",
		iio_dir,
		type,
		number);
		nameFile = fopen(filename, "r");
		if (!nameFile) {
		free(filename);
		continue;
		}
		free(filename);
		fscanf(nameFile, "%s", thisname);
		fclose(nameFile);
		if (strcmp(name, thisname) == 0) {
		closedir(dp);
		return number;
		}
		}
		}
		}
		closedir(dp);
		return -ENODEV;
		}

		int _write_sysfs_int(char filename, char basedir, int val, int verify)
		{
		int ret = 0;
		FILE *sysfsfp;
		int test;
		char *temp = malloc(strlen(basedir) + strlen(filename) + 2);

		if (temp == NULL)
		return -ENOMEM;
		sprintf(temp, "%s/%s", basedir, filename);
		sysfsfp = fopen(temp, "w");
		if (sysfsfp == NULL) {
		printf("failed to open %s\n", temp);
		ret = -errno;
		goto error_free;
		}
		fprintf(sysfsfp, "%d", val);
		fclose(sysfsfp);
		if (verify) {
		sysfsfp = fopen(temp, "r");
		if (sysfsfp == NULL) {
		printf("failed to open %s\n", temp);
		ret = -errno;
		goto error_free;
		}
		fscanf(sysfsfp, "%d", &test);
		fclose(sysfsfp);
		if (test != val) {
		printf("Possible failure in int write %d to %s%s\n",
		val,
		basedir,
		filename);
		ret = -1;
		}
		}
		error_free:
		free(temp);
		return ret;
		}

		int write_sysfs_int(char filename, char basedir, int val)
		{
		return _write_sysfs_int(filename, basedir, val, 0);
		}

		int write_sysfs_int_and_verify(char filename, char basedir, int val)
		{
		return _write_sysfs_int(filename, basedir, val, 1);
		}

		int _write_sysfs_string(char filename, char basedir, char *val, int verify)
		{
		int ret = 0;
		FILE *sysfsfp;
		char *temp = malloc(strlen(basedir) + strlen(filename) + 2);

		if (temp == NULL) {
		printf("Memory allocation failed\n");
		return -ENOMEM;
		}
		sprintf(temp, "%s/%s", basedir, filename);
		sysfsfp = fopen(temp, "w");
		if (sysfsfp == NULL) {
		printf("Could not open %s\n", temp);
		ret = -errno;
		goto error_free;
		}
		fprintf(sysfsfp, "%s", val);
		fclose(sysfsfp);
		if (verify) {
		sysfsfp = fopen(temp, "r");
		if (sysfsfp == NULL) {
		printf("could not open file to verify\n");
		ret = -errno;
		goto error_free;
		}
		fscanf(sysfsfp, "%s", temp);
		fclose(sysfsfp);
		if (strcmp(temp, val) != 0) {
		printf("Possible failure in string write of %s "
		"Should be %s "
		"written to %s\%s\n",
		temp,
		val,
		basedir,
		filename);
		ret = -1;
		}
		}
		error_free:
		free(temp);

		return ret;
		}

		/**
		* write_sysfs_string_and_verify() - string write, readback and verify
		* @filename: name of file to write to
		* @basedir: the sysfs directory in which the file is to be found
		* @val: the string to write
		**/
		int write_sysfs_string_and_verify(char filename, char basedir, char *val)
		{
		return _write_sysfs_string(filename, basedir, val, 1);
		}

		int write_sysfs_string(char filename, char basedir, char *val)
		{
		return _write_sysfs_string(filename, basedir, val, 0);
		}

		int read_sysfs_posint(char filename, char basedir)
		{
		int ret;
		FILE *sysfsfp;
		char *temp = malloc(strlen(basedir) + strlen(filename) + 2);

		if (temp == NULL) {
		printf("Memory allocation failed");
		return -ENOMEM;
		}
		sprintf(temp, "%s/%s", basedir, filename);
		sysfsfp = fopen(temp, "r");
		if (sysfsfp == NULL) {
		ret = -errno;
		goto error_free;
		}
		fscanf(sysfsfp, "%d\n", &ret);
		fclose(sysfsfp);
		error_free:
		free(temp);
		return ret;
		}

		int read_sysfs_float(char filename, char basedir, float *val)
		{
		int ret = 0;
		FILE *sysfsfp;
		char *temp = malloc(strlen(basedir) + strlen(filename) + 2);

		if (temp == NULL) {
		printf("Memory allocation failed");
		return -ENOMEM;
		}
		sprintf(temp, "%s/%s", basedir, filename);
		sysfsfp = fopen(temp, "r");
		if (sysfsfp == NULL) {
		ret = -errno;
		goto error_free;
		}
		fscanf(sysfsfp, "%f\n", val);
		fclose(sysfsfp);
		error_free:
		free(temp);
		return ret;
		}

		int read_sysfs_string(const char filename, const char basedir, char *str)
		{
		int ret = 0;
		FILE *sysfsfp;
		char *temp = malloc(strlen(basedir) + strlen(filename) + 2);

		if (temp == NULL) {
		printf("Memory allocation failed");
		return -ENOMEM;
		}
		sprintf(temp, "%s/%s", basedir, filename);
		sysfsfp = fopen(temp, "r");
		if (sysfsfp == NULL) {
		ret = -errno;
		goto error_free;
		}
		fscanf(sysfsfp, "%s\n", str);
		fclose(sysfsfp);
		error_free:
		free(temp);
		return ret;
		}

drivers/staging/iio/Documentation/iio_utils.h

+26 −638

File changed.

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