staging: iio: update example application.

The application is now considerably more generic and should cope
with all devices in tree.  The process function will need to be
extended to handle other type values as needed.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 391 insertions, 5 deletions

diff --git a/drivers/staging/iio/Documentation/iio_utils.h b/drivers/staging/iio/Documentation/iio_utils.h
index 014f6684faba..03724246b95a 100644
--- a/drivers/staging/iio/Documentation/iio_utils.h
+++ b/drivers/staging/iio/Documentation/iio_utils.h
@@ -10,12 +10,23 @@
 /* Made up value to limit allocation sizes */
 #include <string.h>
 #include <stdlib.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdint.h>
 
 #define IIO_MAX_NAME_LENGTH 30
 
-#define IIO_EVENT_CODE_RING_50_FULL 200
-#define IIO_EVENT_CODE_RING_75_FULL 201
-#define IIO_EVENT_CODE_RING_100_FULL 202
+#define IIO_EV_CLASS_BUFFER		0
+#define IIO_BUFFER_EVENT_CODE(code)		\
+	(IIO_EV_CLASS_BUFFER | (code << 8))
+
+#define IIO_EVENT_CODE_RING_50_FULL	IIO_BUFFER_EVENT_CODE(0)
+#define IIO_EVENT_CODE_RING_75_FULL	IIO_BUFFER_EVENT_CODE(1)
+#define IIO_EVENT_CODE_RING_100_FULL	IIO_BUFFER_EVENT_CODE(2)
+
+
+#define FORMAT_SCAN_ELEMENTS_DIR "%s:buffer0/scan_elements"
+#define FORMAT_TYPE_FILE "%s_type"
 
 const char *iio_dir = "/sys/bus/iio/devices/";
 
@@ -25,6 +36,380 @@ struct iio_event_data {
 };
 
 /**
+ * iioutils_break_up_name() - extract generic name from full channel name
+ * @full_name: the full channel name
+ * @generic_name: the output generic channel name
+ **/
+static 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;
+}
+
+/**
+ * struct iio_channel_info - information about a given channel
+ * @name: channel name
+ * @generic_name: general name for channel type
+ * @scale: scale factor to be applied for conversion to si units
+ * @offset: offset to be applied for conversion to si units
+ * @index: the channel index in the buffer output
+ * @bytes: number of bytes occupied in buffer output
+ * @mask: a bit mask for the raw output
+ * @is_signed: is the raw value stored signed
+ * @enabled: is this channel enabled
+ **/
+struct iio_channel_info {
+	char *name;
+	char *generic_name;
+	float scale;
+	float offset;
+	unsigned index;
+	unsigned bytes;
+	unsigned bits_used;
+	uint64_t mask;
+	unsigned is_signed;
+	unsigned enabled;
+	unsigned location;
+};
+
+/**
+ * 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
+ * @device_dir: the iio device directory
+ * @name: the channel name
+ * @generic_name: the channel type name
+ **/
+inline int iioutils_get_type(unsigned *is_signed,
+			     unsigned *bytes,
+			     unsigned *bits_used,
+			     uint64_t *mask,
+			     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;
+	unsigned sizeint, 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;
+			}
+			fscanf(sysfsfp,
+			       "%c%u/%u", &signchar, bits_used, &padint);
+			*bytes = padint / 8;
+			if (sizeint == 64)
+				*mask = ~0;
+			else
+				*mask = (1 << *bits_used) - 1;
+			if (signchar == 's')
+				*is_signed = 1;
+			else
+				*is_signed = 0;
+		}
+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;
+}
+
+inline 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;
+}
+
+
+/**
+ * build_channel_array() - function to figure out what channels are present
+ * @device_dir: the IIO device directory in sysfs
+ * @
+ **/
+inline int build_channel_array(const char *device_dir,
+			      struct iio_channel_info **ci_array,
+			      int *counter)
+{
+	DIR *dp;
+	FILE *sysfsfp;
+	int count = 0, temp, 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, "%u", &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);
+	while (ent = readdir(dp), ent != NULL) {
+		if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
+			   "_en") == 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, "%u", &current->enabled);
+			fclose(sysfsfp);
+			free(filename);
+			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->mask,
+						device_dir,
+						current->name,
+						current->generic_name);
+		}
+	}
+	/* reorder so that the array is in index order*/
+	current = malloc(sizeof(**ci_array)**counter);
+	if (current == NULL) {
+		ret = -ENOMEM;
+		goto error_cleanup_array;
+	}
+	closedir(dp);
+	count = 0;
+	temp = 0;
+	while (count < *counter)
+		for (i = 0; i < *counter; i++)
+			if ((*ci_array)[i].index == temp) {
+				memcpy(&current[count++],
+				       &(*ci_array)[i],
+				       sizeof(*current));
+				temp++;
+				break;
+			}
+	free(*ci_array);
+	*ci_array = current;
+
+	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
@@ -40,7 +425,6 @@ inline int find_type_by_name(const char *name, const char *type)
 	DIR *dp;
 	char thisname[IIO_MAX_NAME_LENGTH];
 	char *filename;
-	struct stat Stat;
 
 	dp = opendir(iio_dir);
 	if (dp == NULL) {
@@ -134,7 +518,7 @@ int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 
 int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 {
-	int ret;
+	int ret = 0;
 	FILE  *sysfsfp;
 	char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 	if (temp == NULL) {
@@ -153,6 +537,7 @@ int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 	if (verify) {
 		sysfsfp = fopen(temp, "r");
 		if (sysfsfp == NULL) {
+			printf("could not open file to verify\n");
 			ret = -errno;
 			goto error_free;
 		}
@@ -173,6 +558,7 @@ error_free:
 
 	return ret;
 }
+
 /**
  * write_sysfs_string_and_verify() - string write, readback and verify
  * @filename: name of file to write to