Make mixer ioctls load from a memory buffer rather than a file. This is prep for uploading the memory buffer to IO to be processed there.

This commit is contained in:
px4dev
2012-12-29 00:01:04 -08:00
parent f0da789626
commit 35c82ff2fc
10 changed files with 536 additions and 464 deletions
+7 -81
View File
@@ -137,89 +137,15 @@ NullMixer::groups_required(uint32_t &groups)
}
/****************************************************************************/
SimpleMixer::SimpleMixer(ControlCallback control_cb,
uintptr_t cb_handle,
mixer_simple_s *mixinfo) :
Mixer(control_cb, cb_handle),
_info(mixinfo)
NullMixer *
NullMixer::from_text(const char *buf, unsigned &buflen)
{
}
NullMixer *nm = nullptr;
SimpleMixer::~SimpleMixer()
{
if (_info != nullptr)
free(_info);
}
unsigned
SimpleMixer::mix(float *outputs, unsigned space)
{
float sum = 0.0f;
if (_info == nullptr)
return 0;
if (space < 1)
return 0;
for (unsigned i = 0; i < _info->control_count; i++) {
float input;
_control_cb(_cb_handle,
_info->controls[i].control_group,
_info->controls[i].control_index,
input);
sum += scale(_info->controls[i].scaler, input);
if ((buflen >= 2) && (buf[0] == 'Z') && (buf[1] == ':')) {
nm = new NullMixer;
buflen -= 2;
}
*outputs = scale(_info->output_scaler, sum);
return 1;
}
void
SimpleMixer::groups_required(uint32_t &groups)
{
for (unsigned i = 0; i < _info->control_count; i++)
groups |= 1 << _info->controls[i].control_group;
}
int
SimpleMixer::check()
{
int ret;
float junk;
/* sanity that presumes that a mixer includes a control no more than once */
/* max of 32 groups due to groups_required API */
if (_info->control_count > 32)
return -2;
/* validate the output scaler */
ret = scale_check(_info->output_scaler);
if (ret != 0)
return ret;
/* validate input scalers */
for (unsigned i = 0; i < _info->control_count; i++) {
/* verify that we can fetch the control */
if (_control_cb(_cb_handle,
_info->controls[i].control_group,
_info->controls[i].control_index,
junk) != 0) {
return -3;
}
/* validate the scaler */
ret = scale_check(_info->controls[i].scaler);
if (ret != 0)
return (10 * i + ret);
}
return 0;
return nm;
}
+100 -40
View File
@@ -234,50 +234,45 @@ public:
void add_mixer(Mixer *mixer);
/**
* Reads a mixer definition from a file and configures a corresponding
* group.
* Adds mixers to the group based on a text description in a buffer.
*
* The mixer group must be empty when this function is called.
* Mixer definitions begin with a single capital letter and a colon.
* The actual format of the mixer definition varies with the individual
* mixers; they are summarised here, but see ROMFS/mixers/README for
* more details.
*
* A mixer definition is a text representation of the configuration of a
* mixer. Definition lines begin with a capital letter followed by a colon.
* Null Mixer
* ..........
*
* The null mixer definition has the form:
*
* Z:
*
* Simple Mixer
* ............
*
* A simple mixer definition begins with:
*
* M: <control count>
* O: <-ve scale> <+ve scale> <offset> <lower limit> <upper limit>
*
* The definition continues with <control count> entries describing the control
* inputs and their scaling, in the form:
*
* S: <group> <index> <-ve scale> <+ve scale> <offset> <lower limit> <upper limit>
*
* Multirotor Mixer
* ................
*
* The multirotor mixer definition is a single line of the form:
*
* R: <geometry> <roll scale> <pitch scale> <yaw scale> <deadband>
*
* Null Mixer:
*
* Z:
*
* This mixer generates a constant zero output, and is normally used to
* skip over outputs that are not in use.
*
* Simple Mixer:
*
* M: <scaler count>
* S: <control group> <control index> <negative_scale*> <positive_scale*> <offset*> <lower_limit*> <upper_limit*>
* S: ...
*
* The definition consists of a single-line header indicating the
* number of scalers and then one line defining each scaler. The first
* scaler in the file is always the output scaler, followed by the input
* scalers.
*
* The <control ...> values for the output scaler are ignored by the mixer.
*
*
*
* Values marked * are integers representing floating point values; values are
* scaled by 10000 on load/save.
*
* Multiple mixer definitions may be stored in a single file; it is assumed that
* the reader will know how many to expect and read accordingly.
*
* A mixer entry with a scaler count of zero indicates a disabled mixer. This
* will return NULL for the mixer when processed by this function, and will be
* generated by passing NULL as the mixer to mixer_save.
*
* @param path The mixer configuration file to read.
* @param buf The mixer configuration buffer.
* @param buflen The length of the buffer.
* @return Zero on successful load, nonzero otherwise.
*/
int load_from_file(const char *path);
int load_from_buf(const char *buf, unsigned buflen);
private:
Mixer *_first; /**< linked list of mixers */
@@ -294,6 +289,21 @@ public:
NullMixer();
~NullMixer() {};
/**
* Factory method.
*
* Given a pointer to a buffer containing a text description of the mixer,
* returns a pointer to a new instance of the mixer.
*
* @param buf Buffer containing a text description of
* the mixer.
* @param buflen Length of the buffer in bytes, adjusted
* to reflect the bytes consumed.
* @return A new NullMixer instance, or nullptr
* if the text format is bad.
*/
static NullMixer *from_text(const char *buf, unsigned &buflen);
virtual unsigned mix(float *outputs, unsigned space);
virtual void groups_required(uint32_t &groups);
};
@@ -318,6 +328,27 @@ public:
mixer_simple_s *mixinfo);
~SimpleMixer();
/**
* Factory method.
*
* Given a pointer to a buffer containing a text description of the mixer,
* returns a pointer to a new instance of the mixer.
*
* @param control_cb The callback to invoke when fetching a
* control value.
* @param cb_handle Handle passed to the control callback.
* @param buf Buffer containing a text description of
* the mixer.
* @param buflen Length of the buffer in bytes, adjusted
* to reflect the bytes consumed.
* @return A new SimpleMixer instance, or nullptr
* if the text format is bad.
*/
static SimpleMixer *from_text(Mixer::ControlCallback control_cb,
uintptr_t cb_handle,
const char *buf,
unsigned &buflen);
virtual unsigned mix(float *outputs, unsigned space);
virtual void groups_required(uint32_t &groups);
@@ -330,10 +361,18 @@ public:
* @return Zero if the mixer makes sense, nonzero otherwise.
*/
int check();
protected:
private:
mixer_simple_s *_info;
mixer_simple_s *_info;
static int parse_output_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler);
static int parse_control_scaler(const char *buf,
unsigned &buflen,
mixer_scaler_s &scaler,
uint8_t &control_group,
uint8_t &control_index);
};
/**
@@ -395,6 +434,27 @@ public:
float deadband);
~MultirotorMixer();
/**
* Factory method.
*
* Given a pointer to a buffer containing a text description of the mixer,
* returns a pointer to a new instance of the mixer.
*
* @param control_cb The callback to invoke when fetching a
* control value.
* @param cb_handle Handle passed to the control callback.
* @param buf Buffer containing a text description of
* the mixer.
* @param buflen Length of the buffer in bytes, adjusted
* to reflect the bytes consumed.
* @return A new MultirotorMixer instance, or nullptr
* if the text format is bad.
*/
static MultirotorMixer *from_text(Mixer::ControlCallback control_cb,
uintptr_t cb_handle,
const char *buf,
unsigned &buflen);
virtual unsigned mix(float *outputs, unsigned space);
virtual void groups_required(uint32_t &groups);
+28 -278
View File
@@ -56,250 +56,6 @@
#define debug(fmt, args...) do { } while(0)
//#define debug(fmt, args...) do { printf("[mixer] " fmt "\n", ##args); } while(0)
namespace
{
/**
* Effectively fdgets() with some extra smarts.
*/
static int
mixer_getline(int fd, char *line, unsigned maxlen)
{
/* reduce line budget by 1 to account for terminal NUL */
maxlen--;
/* loop looking for a non-comment line */
for (;;) {
int ret;
char c;
char *p = line;
/* loop reading characters for this line */
for (;;) {
ret = read(fd, &c, 1);
/* on error or EOF, return same */
if (ret <= 0) {
debug("read: EOF");
return ret;
}
/* ignore carriage returns */
if (c == '\r')
continue;
/* line termination */
if (c == '\n') {
/* ignore malformed lines */
if ((p - line) < 4)
break;
if (line[1] != ':')
break;
/* terminate line as string and return */
*p = '\0';
debug("read: '%s'", line);
return 1;
}
/* if we have space, accumulate the byte and go on */
if ((p - line) < maxlen)
*p++ = c;
}
}
}
/**
* Parse an output scaler from the buffer.
*/
static int
mixer_parse_output_scaler(const char *buf, mixer_scaler_s &scaler)
{
int s[5];
if (sscanf(buf, "O: %d %d %d %d %d",
&s[0], &s[1], &s[2], &s[3], &s[4]) != 5) {
debug("scaler parse failed on '%s'", buf);
return -1;
}
scaler.negative_scale = s[0] / 10000.0f;
scaler.positive_scale = s[1] / 10000.0f;
scaler.offset = s[2] / 10000.0f;
scaler.min_output = s[3] / 10000.0f;
scaler.max_output = s[4] / 10000.0f;
return 0;
}
/**
* Parse a control scaler from the buffer.
*/
static int
mixer_parse_control_scaler(const char *buf, mixer_scaler_s &scaler, uint8_t &control_group, uint8_t &control_index)
{
unsigned u[2];
int s[5];
if (sscanf(buf, "S: %u %u %d %d %d %d %d",
&u[0], &u[1], &s[0], &s[1], &s[2], &s[3], &s[4]) != 7) {
debug("scaler parse failed on '%s'", buf);
return -1;
}
control_group = u[0];
control_index = u[1];
scaler.negative_scale = s[0] / 10000.0f;
scaler.positive_scale = s[1] / 10000.0f;
scaler.offset = s[2] / 10000.0f;
scaler.min_output = s[3] / 10000.0f;
scaler.max_output = s[4] / 10000.0f;
return 0;
}
SimpleMixer *
mixer_load_simple(Mixer::ControlCallback control_cb, uintptr_t cb_handle, int fd, unsigned inputs)
{
mixer_simple_s *mixinfo = nullptr;
char buf[60];
int ret;
/* let's assume we're going to read a simple mixer */
mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(inputs));
mixinfo->control_count = inputs;
/* first, get the output scaler */
ret = mixer_getline(fd, buf, sizeof(buf));
if (ret < 1) {
debug("failed reading for output scaler");
goto fail;
}
if (mixer_parse_output_scaler(buf, mixinfo->output_scaler)) {
debug("failed parsing output scaler");
goto fail;
}
/* now get any inputs */
for (unsigned i = 0; i < inputs; i++) {
ret = mixer_getline(fd, buf, sizeof(buf));
if (ret < 1) {
debug("failed reading for control scaler");
goto fail;
}
if (mixer_parse_control_scaler(buf,
mixinfo->controls[i].scaler,
mixinfo->controls[i].control_group,
mixinfo->controls[i].control_index)) {
debug("failed parsing control scaler");
goto fail;
}
debug("got control %d", i);
}
/* XXX should be a factory that validates the mixinfo ... */
return new SimpleMixer(control_cb, cb_handle, mixinfo);
fail:
free(mixinfo);
return nullptr;
}
MultirotorMixer *
mixer_load_multirotor(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf)
{
MultirotorMixer::Geometry geometry;
char geomname[8];
int s[4];
if (sscanf(buf, "R: %s %d %d %d %d", geomname, &s[0], &s[1], &s[2], &s[3]) != 5) {
debug("multirotor parse failed on '%s'", buf);
return nullptr;
}
if (!strcmp(geomname, "4+")) {
geometry = MultirotorMixer::QUAD_PLUS;
} else if (!strcmp(geomname, "4x")) {
geometry = MultirotorMixer::QUAD_X;
} else if (!strcmp(geomname, "6+")) {
geometry = MultirotorMixer::HEX_PLUS;
} else if (!strcmp(geomname, "6x")) {
geometry = MultirotorMixer::HEX_X;
} else if (!strcmp(geomname, "8+")) {
geometry = MultirotorMixer::OCTA_PLUS;
} else if (!strcmp(geomname, "8x")) {
geometry = MultirotorMixer::OCTA_X;
} else {
debug("unrecognised geometry '%s'", geomname);
return nullptr;
}
return new MultirotorMixer(
control_cb,
cb_handle,
geometry,
s[0] / 10000.0f,
s[1] / 10000.0f,
s[2] / 10000.0f,
s[3] / 10000.0f);
}
int
mixer_load(Mixer::ControlCallback control_cb, uintptr_t cb_handle, int fd, Mixer *&mixer)
{
int ret;
char buf[60];
unsigned inputs;
ret = mixer_getline(fd, buf, sizeof(buf));
/* end of file or error ?*/
if (ret < 1) {
debug("getline %d", ret);
return ret;
}
/* slot is empty - allocate a null mixer */
if (buf[0] == 'Z') {
debug("got null mixer");
mixer = new NullMixer();
return 1;
}
/* is it a simple mixer? */
if (sscanf(buf, "M: %u", &inputs) == 1) {
debug("got simple mixer with %d inputs", inputs);
mixer = mixer_load_simple(control_cb, cb_handle, fd, inputs);
return (mixer == nullptr) ? -1 : 1;
}
/* is it a multirotor mixer? */
if (buf[0] == 'R') {
debug("got a multirotor mixer");
mixer = mixer_load_multirotor(control_cb, cb_handle, buf);
return (mixer == nullptr) ? -1 : 1;
}
/* we don't recognise the mixer type */
debug("unrecognized mixer type '%c'", buf[0]);
return -1;
}
} // namespace
MixerGroup::MixerGroup(ControlCallback control_cb, uintptr_t cb_handle) :
Mixer(control_cb, cb_handle),
_first(nullptr)
@@ -358,44 +114,38 @@ MixerGroup::groups_required(uint32_t &groups)
}
int
MixerGroup::load_from_file(const char *path)
MixerGroup::load_from_buf(const char *buf, unsigned buflen)
{
if (_first != nullptr)
return -1;
int ret = -1;
const char *end = buf + buflen;
int fd = open(path, O_RDONLY);
/* loop until we have consumed the buffer */
while (buflen > 0) {
Mixer *m = nullptr;
const char *p = end - buflen;
if (fd < 0) {
debug("failed to open %s", path);
return -1;
}
for (unsigned count = 0;; count++) {
int result;
Mixer *mixer;
result = mixer_load(_control_cb,
_cb_handle,
fd,
mixer);
/* error? */
if (result < 0) {
debug("error");
return -1;
/* use the next character as a hint to decide which mixer class to construct */
switch (*p) {
case 'Z':
m = NullMixer::from_text(p, buflen);
break;
case 'M':
m = SimpleMixer::from_text(_control_cb, _cb_handle, p, buflen);
break;
case 'R':
m = MultirotorMixer::from_text(_control_cb, _cb_handle, p, buflen);
break;
default:
/* it's probably junk or whitespace */
break;
}
/* EOF or error */
if (result < 1) {
printf("[mixer] loaded %u mixers\n", count);
debug("EOF");
break;
if (m != nullptr) {
add_mixer(m);
ret = 0;
} else {
/* skip whitespace or junk in the buffer */
buflen--;
}
debug("loaded mixer %p", mixer);
add_mixer(mixer);
}
close(fd);
return 0;
return ret;
}
+56
View File
@@ -54,6 +54,9 @@
#include "mixer.h"
#define debug(fmt, args...) do { } while(0)
//#define debug(fmt, args...) do { printf("[mixer] " fmt "\n", ##args); } while(0)
#define CW (-1.0f)
#define CCW (1.0f)
@@ -151,6 +154,59 @@ MultirotorMixer::~MultirotorMixer()
{
}
MultirotorMixer *
MultirotorMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf, unsigned &buflen)
{
MultirotorMixer::Geometry geometry;
char geomname[8];
int s[4];
int used;
if (sscanf(buf, "R: %s %d %d %d %d%n", geomname, &s[0], &s[1], &s[2], &s[3], &used) != 5) {
debug("multirotor parse failed on '%s'", buf);
return nullptr;
}
if (used > (int)buflen) {
debug("multirotor spec used %d of %u", used, buflen);
return nullptr;
}
buflen -= used;
if (!strcmp(geomname, "4+")) {
geometry = MultirotorMixer::QUAD_PLUS;
} else if (!strcmp(geomname, "4x")) {
geometry = MultirotorMixer::QUAD_X;
} else if (!strcmp(geomname, "6+")) {
geometry = MultirotorMixer::HEX_PLUS;
} else if (!strcmp(geomname, "6x")) {
geometry = MultirotorMixer::HEX_X;
} else if (!strcmp(geomname, "8+")) {
geometry = MultirotorMixer::OCTA_PLUS;
} else if (!strcmp(geomname, "8x")) {
geometry = MultirotorMixer::OCTA_X;
} else {
debug("unrecognised geometry '%s'", geomname);
return nullptr;
}
debug("adding multirotor mixer '%s'", geomname);
return new MultirotorMixer(
control_cb,
cb_handle,
geometry,
s[0] / 10000.0f,
s[1] / 10000.0f,
s[2] / 10000.0f,
s[3] / 10000.0f);
}
unsigned
MultirotorMixer::mix(float *outputs, unsigned space)
{
+260
View File
@@ -0,0 +1,260 @@
/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file mixer_simple.cpp
*
* Simple summing mixer.
*/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <ctype.h>
#include "mixer.h"
#define debug(fmt, args...) do { } while(0)
//#define debug(fmt, args...) do { printf("[mixer] " fmt "\n", ##args); } while(0)
SimpleMixer::SimpleMixer(ControlCallback control_cb,
uintptr_t cb_handle,
mixer_simple_s *mixinfo) :
Mixer(control_cb, cb_handle),
_info(mixinfo)
{
}
SimpleMixer::~SimpleMixer()
{
if (_info != nullptr)
free(_info);
}
static const char *
skipspace(const char *p, unsigned &len)
{
while (isspace(*p)) {
if (len == 0)
return nullptr;
len--;
p++;
}
return p;
}
int
SimpleMixer::parse_output_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler)
{
int ret;
int s[5];
int used;
buf = skipspace(buf, buflen);
if (buflen < 16)
return -1;
if ((ret = sscanf(buf, "O: %d %d %d %d %d%n",
&s[0], &s[1], &s[2], &s[3], &s[4], &used)) != 5) {
debug("scaler parse failed on '%s' (got %d)", buf, ret);
return -1;
}
buflen -= used;
scaler.negative_scale = s[0] / 10000.0f;
scaler.positive_scale = s[1] / 10000.0f;
scaler.offset = s[2] / 10000.0f;
scaler.min_output = s[3] / 10000.0f;
scaler.max_output = s[4] / 10000.0f;
return 0;
}
int
SimpleMixer::parse_control_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler, uint8_t &control_group, uint8_t &control_index)
{
unsigned u[2];
int s[5];
int used;
buf = skipspace(buf, buflen);
if (buflen < 16)
return -1;
if (sscanf(buf, "S: %u %u %d %d %d %d %d%n",
&u[0], &u[1], &s[0], &s[1], &s[2], &s[3], &s[4], &used) != 7) {
debug("control parse failed on '%s'", buf);
return -1;
}
buflen -= used;
control_group = u[0];
control_index = u[1];
scaler.negative_scale = s[0] / 10000.0f;
scaler.positive_scale = s[1] / 10000.0f;
scaler.offset = s[2] / 10000.0f;
scaler.min_output = s[3] / 10000.0f;
scaler.max_output = s[4] / 10000.0f;
return 0;
}
SimpleMixer *
SimpleMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf, unsigned &buflen)
{
SimpleMixer *sm = nullptr;
mixer_simple_s *mixinfo = nullptr;
unsigned inputs;
int used;
const char *end = buf + buflen;
/* get the base info for the mixer */
if (sscanf(buf, "M: %u%n", &inputs, &used) != 1) {
debug("simple parse failed on '%s'", buf);
goto out;
}
buflen -= used;
mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(inputs));
if (mixinfo == nullptr) {
debug("could not allocate memory for mixer info");
goto out;
}
mixinfo->control_count = inputs;
if (parse_output_scaler(end - buflen, buflen, mixinfo->output_scaler))
goto out;
for (unsigned i = 0; i < inputs; i++) {
if (parse_control_scaler(end - buflen, buflen,
mixinfo->controls[i].scaler,
mixinfo->controls[i].control_group,
mixinfo->controls[i].control_index))
goto out;
}
sm = new SimpleMixer(control_cb, cb_handle, mixinfo);
if (sm != nullptr) {
mixinfo = nullptr;
debug("loaded mixer with %d inputs", inputs);
} else {
debug("could not allocate memory for mixer");
}
out:
if (mixinfo != nullptr)
free(mixinfo);
return sm;
}
unsigned
SimpleMixer::mix(float *outputs, unsigned space)
{
float sum = 0.0f;
if (_info == nullptr)
return 0;
if (space < 1)
return 0;
for (unsigned i = 0; i < _info->control_count; i++) {
float input;
_control_cb(_cb_handle,
_info->controls[i].control_group,
_info->controls[i].control_index,
input);
sum += scale(_info->controls[i].scaler, input);
}
*outputs = scale(_info->output_scaler, sum);
return 1;
}
void
SimpleMixer::groups_required(uint32_t &groups)
{
for (unsigned i = 0; i < _info->control_count; i++)
groups |= 1 << _info->controls[i].control_group;
}
int
SimpleMixer::check()
{
int ret;
float junk;
/* sanity that presumes that a mixer includes a control no more than once */
/* max of 32 groups due to groups_required API */
if (_info->control_count > 32)
return -2;
/* validate the output scaler */
ret = scale_check(_info->output_scaler);
if (ret != 0)
return ret;
/* validate input scalers */
for (unsigned i = 0; i < _info->control_count; i++) {
/* verify that we can fetch the control */
if (_control_cb(_cb_handle,
_info->controls[i].control_group,
_info->controls[i].control_index,
junk) != 0) {
return -3;
}
/* validate the scaler */
ret = scale_check(_info->controls[i].scaler);
if (ret != 0)
return (10 * i + ret);
}
return 0;
}