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intel_idle.c
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Rafael J. Wysocki authored
In certain system configurations it may not be desirable to use some C-states assumed to be available by intel_idle and the driver needs to be prevented from using them even before the cpuidle sysfs interface becomes accessible to user space. Currently, the only way to achieve that is by setting the 'max_cstate' module parameter to a value lower than the index of the shallowest of the C-states in question, but that may be overly intrusive, because it effectively makes all of the idle states deeper than the 'max_cstate' one go away (and the C-state to avoid may be in the middle of the range normally regarded as available). To allow that limitation to be overcome, introduce a new module parameter called 'states_off' to represent a list of idle states to be disabled by default in the form of a bitmask and update the documentation to cover it. Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Rafael J. Wysocki authoredIn certain system configurations it may not be desirable to use some C-states assumed to be available by intel_idle and the driver needs to be prevented from using them even before the cpuidle sysfs interface becomes accessible to user space. Currently, the only way to achieve that is by setting the 'max_cstate' module parameter to a value lower than the index of the shallowest of the C-states in question, but that may be overly intrusive, because it effectively makes all of the idle states deeper than the 'max_cstate' one go away (and the C-state to avoid may be in the middle of the range normally regarded as available). To allow that limitation to be overcome, introduce a new module parameter called 'states_off' to represent a list of idle states to be disabled by default in the form of a bitmask and update the documentation to cover it. Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com>
iio_generic_buffer.c 16.30 KiB
/* Industrialio buffer test code.
*
* 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.
*
* This program is primarily intended as an example application.
* Reads the current buffer setup from sysfs and starts a short capture
* from the specified device, pretty printing the result after appropriate
* conversion.
*
* Command line parameters
* generic_buffer -n <device_name> -t <trigger_name>
* If trigger name is not specified the program assumes you want a dataready
* trigger associated with the device and goes looking for it.
*
*/
#include <unistd.h>
#include <stdlib.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/dir.h>
#include <linux/types.h>
#include <string.h>
#include <poll.h>
#include <endian.h>
#include <getopt.h>
#include <inttypes.h>
#include <stdbool.h>
#include <signal.h>
#include "iio_utils.h"
/**
* enum autochan - state for the automatic channel enabling mechanism
*/
enum autochan {
AUTOCHANNELS_DISABLED,
AUTOCHANNELS_ENABLED,
AUTOCHANNELS_ACTIVE,
};
/**
* size_from_channelarray() - calculate the storage size of a scan
* @channels: the channel info array
* @num_channels: number of channels
*
* Has the side effect of filling the channels[i].location values used
* in processing the buffer output.
**/
int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
{
int bytes = 0;
int i = 0;
while (i < num_channels) {
if (bytes % channels[i].bytes == 0)
channels[i].location = bytes;
else
channels[i].location = bytes - bytes % channels[i].bytes
+ channels[i].bytes;
bytes = channels[i].location + channels[i].bytes;
i++;
}
return bytes;
}
void print1byte(uint8_t input, struct iio_channel_info *info)
{
/*
* Shift before conversion to avoid sign extension
* of left aligned data
*/
input >>= info->shift;
input &= info->mask;
if (info->is_signed) {
int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
(8 - info->bits_used);
printf("%05f ", ((float)val + info->offset) * info->scale);
} else {
printf("%05f ", ((float)input + info->offset) * info->scale);
}
}
void print2byte(uint16_t input, struct iio_channel_info *info)
{
/* First swap if incorrect endian */
if (info->be)
input = be16toh(input);
else
input = le16toh(input);
/*
* Shift before conversion to avoid sign extension
* of left aligned data
*/
input >>= info->shift;
input &= info->mask;
if (info->is_signed) {
int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
(16 - info->bits_used);
printf("%05f ", ((float)val + info->offset) * info->scale);
} else {
printf("%05f ", ((float)input + info->offset) * info->scale);
}
}
void print4byte(uint32_t input, struct iio_channel_info *info)
{
/* First swap if incorrect endian */
if (info->be)
input = be32toh(input);
else
input = le32toh(input);
/*
* Shift before conversion to avoid sign extension
* of left aligned data
*/
input >>= info->shift;
input &= info->mask;
if (info->is_signed) {
int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
(32 - info->bits_used);
printf("%05f ", ((float)val + info->offset) * info->scale);
} else {
printf("%05f ", ((float)input + info->offset) * info->scale);
}
}
void print8byte(uint64_t input, struct iio_channel_info *info)
{
/* First swap if incorrect endian */
if (info->be)
input = be64toh(input);
else
input = le64toh(input);
/*
* Shift before conversion to avoid sign extension
* of left aligned data
*/
input >>= info->shift;
input &= info->mask;
if (info->is_signed) {
int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
(64 - info->bits_used);
/* special case for timestamp */
if (info->scale == 1.0f && info->offset == 0.0f)
printf("%" PRId64 " ", val);
else
printf("%05f ",
((float)val + info->offset) * info->scale);
} else {
printf("%05f ", ((float)input + info->offset) * info->scale);
}
}
/**
* process_scan() - print out the values in SI units
* @data: pointer to the start of the scan
* @channels: information about the channels.
* Note: size_from_channelarray must have been called first
* to fill the location offsets.
* @num_channels: number of channels
**/
void process_scan(char *data,
struct iio_channel_info *channels,
int num_channels)
{
int k;
for (k = 0; k < num_channels; k++)
switch (channels[k].bytes) {
/* only a few cases implemented so far */
case 1:
print1byte(*(uint8_t *)(data + channels[k].location),
&channels[k]);
break;
case 2:
print2byte(*(uint16_t *)(data + channels[k].location),
&channels[k]);
break;
case 4:
print4byte(*(uint32_t *)(data + channels[k].location),
&channels[k]);
break;
case 8:
print8byte(*(uint64_t *)(data + channels[k].location),
&channels[k]);
break;
default:
break;
}
printf("\n");
}
static int enable_disable_all_channels(char *dev_dir_name, int enable)
{
const struct dirent *ent;
char scanelemdir[256];
DIR *dp;
int ret;
snprintf(scanelemdir, sizeof(scanelemdir),
FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name);
scanelemdir[sizeof(scanelemdir)-1] = '\0';
dp = opendir(scanelemdir);
if (!dp) {
fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
scanelemdir);
return -EIO;
}
ret = -ENOENT;
while (ent = readdir(dp), ent) {
if (iioutils_check_suffix(ent->d_name, "_en")) {
printf("%sabling: %s\n",
enable ? "En" : "Dis",
ent->d_name);
ret = write_sysfs_int(ent->d_name, scanelemdir,
enable);
if (ret < 0)
fprintf(stderr, "Failed to enable/disable %s\n",
ent->d_name);
}
}
if (closedir(dp) == -1) {
perror("Enabling/disabling channels: "
"Failed to close directory");
return -errno;
}
return 0;
}
void print_usage(void)
{
fprintf(stderr, "Usage: generic_buffer [options]...\n"
"Capture, convert and output data from IIO device buffer\n"
" -a Auto-activate all available channels\n"
" -A Force-activate ALL channels\n"
" -c <n> Do n conversions, or loop forever if n < 0\n"
" -e Disable wait for event (new data)\n"
" -g Use trigger-less mode\n"
" -l <n> Set buffer length to n samples\n"
" --device-name -n <name>\n"
" --device-num -N <num>\n"
" Set device by name or number (mandatory)\n"
" --trigger-name -t <name>\n"
" --trigger-num -T <num>\n"
" Set trigger by name or number\n"
" -w <n> Set delay between reads in us (event-less mode)\n");
}
enum autochan autochannels = AUTOCHANNELS_DISABLED;
char *dev_dir_name = NULL;
char *buf_dir_name = NULL;
bool current_trigger_set = false;
void cleanup(void)
{
int ret;
/* Disable trigger */
if (dev_dir_name && current_trigger_set) {
/* Disconnect the trigger - just write a dummy name. */
ret = write_sysfs_string("trigger/current_trigger",
dev_dir_name, "NULL");
if (ret < 0)
fprintf(stderr, "Failed to disable trigger: %s\n",
strerror(-ret));
current_trigger_set = false;
}
/* Disable buffer */
if (buf_dir_name) {
ret = write_sysfs_int("enable", buf_dir_name, 0);
if (ret < 0)
fprintf(stderr, "Failed to disable buffer: %s\n",
strerror(-ret));
}
/* Disable channels if auto-enabled */
if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
ret = enable_disable_all_channels(dev_dir_name, 0);
if (ret)
fprintf(stderr, "Failed to disable all channels\n");
autochannels = AUTOCHANNELS_DISABLED;
}
}
void sig_handler(int signum)
{
fprintf(stderr, "Caught signal %d\n", signum);
cleanup();
exit(-signum);
}
void register_cleanup(void)
{
struct sigaction sa = { .sa_handler = sig_handler };
const int signums[] = { SIGINT, SIGTERM, SIGABRT };
int ret, i;
for (i = 0; i < ARRAY_SIZE(signums); ++i) {
ret = sigaction(signums[i], &sa, NULL);
if (ret) {
perror("Failed to register signal handler");
exit(-1);
}
}
}
static const struct option longopts[] = {
{ "device-name", 1, 0, 'n' },
{ "device-num", 1, 0, 'N' },
{ "trigger-name", 1, 0, 't' },
{ "trigger-num", 1, 0, 'T' },
{ },
};
int main(int argc, char **argv)
{
long long num_loops = 2;
unsigned long timedelay = 1000000;
unsigned long buf_len = 128;
ssize_t i;
unsigned long long j;
unsigned long toread;
int ret, c;
int fp = -1;
int num_channels = 0;
char *trigger_name = NULL, *device_name = NULL;
char *data = NULL;
ssize_t read_size;
int dev_num = -1, trig_num = -1;
char *buffer_access = NULL;
int scan_size;
int noevents = 0;
int notrigger = 0;
char *dummy;
bool force_autochannels = false;
struct iio_channel_info *channels = NULL;
register_cleanup();
while ((c = getopt_long(argc, argv, "aAc:egl:n:N:t:T:w:?", longopts,
NULL)) != -1) {
switch (c) {
case 'a':
autochannels = AUTOCHANNELS_ENABLED;
break;
case 'A':
autochannels = AUTOCHANNELS_ENABLED;
force_autochannels = true;
break;
case 'c':
errno = 0;
num_loops = strtoll(optarg, &dummy, 10);
if (errno) {
ret = -errno;
goto error;
}
break;
case 'e':
noevents = 1;
break;
case 'g':
notrigger = 1;
break;
case 'l':
errno = 0;
buf_len = strtoul(optarg, &dummy, 10);
if (errno) {
ret = -errno;
goto error;
}
break;
case 'n':
device_name = strdup(optarg);
break;
case 'N':
errno = 0;
dev_num = strtoul(optarg, &dummy, 10);
if (errno) {
ret = -errno;
goto error;
}
break;
case 't':
trigger_name = strdup(optarg);
break;
case 'T':
errno = 0;
trig_num = strtoul(optarg, &dummy, 10);
if (errno)
return -errno;
break;
case 'w':
errno = 0;
timedelay = strtoul(optarg, &dummy, 10);
if (errno) {
ret = -errno;
goto error;
}
break;
case '?':
print_usage();
ret = -1;
goto error;
}
}
/* Find the device requested */
if (dev_num < 0 && !device_name) {
fprintf(stderr, "Device not set\n");
print_usage();
ret = -1;
goto error;
} else if (dev_num >= 0 && device_name) {
fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
print_usage();
ret = -1;
goto error;
} else if (dev_num < 0) {
dev_num = find_type_by_name(device_name, "iio:device");
if (dev_num < 0) {
fprintf(stderr, "Failed to find the %s\n", device_name);
ret = dev_num;
goto error;
}
}
printf("iio device number being used is %d\n", dev_num);
ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
if (ret < 0)
return -ENOMEM;
/* Fetch device_name if specified by number */
if (!device_name) {
device_name = malloc(IIO_MAX_NAME_LENGTH);
if (!device_name) {
ret = -ENOMEM;
goto error;
}
ret = read_sysfs_string("name", dev_dir_name, device_name);
if (ret < 0) {
fprintf(stderr, "Failed to read name of device %d\n", dev_num);
goto error;
}
}
if (notrigger) {
printf("trigger-less mode selected\n");
} else if (trig_num >= 0) {
char *trig_dev_name;
ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
if (ret < 0) {
return -ENOMEM;
}
trigger_name = malloc(IIO_MAX_NAME_LENGTH);
ret = read_sysfs_string("name", trig_dev_name, trigger_name);
free(trig_dev_name);
if (ret < 0) {
fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
return ret;
}
printf("iio trigger number being used is %d\n", trig_num);
} else {
if (!trigger_name) {
/*
* Build the trigger name. If it is device associated
* its name is <device_name>_dev[n] where n matches
* the device number found above.
*/
ret = asprintf(&trigger_name,
"%s-dev%d", device_name, dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error;
}
}
/* Look for this "-devN" trigger */
trig_num = find_type_by_name(trigger_name, "trigger");
if (trig_num < 0) {
/* OK try the simpler "-trigger" suffix instead */
free(trigger_name);
ret = asprintf(&trigger_name,
"%s-trigger", device_name);
if (ret < 0) {
ret = -ENOMEM;
goto error;
}
}
trig_num = find_type_by_name(trigger_name, "trigger");
if (trig_num < 0) {
fprintf(stderr, "Failed to find the trigger %s\n",
trigger_name);
ret = trig_num;
goto error;
}
printf("iio trigger number being used is %d\n", trig_num);
}
/*
* Parse the files in scan_elements to identify what channels are
* present
*/
ret = build_channel_array(dev_dir_name, &channels, &num_channels);
if (ret) {
fprintf(stderr, "Problem reading scan element information\n"
"diag %s\n", dev_dir_name);
goto error;
}
if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&
!force_autochannels) {
fprintf(stderr, "Auto-channels selected but some channels "
"are already activated in sysfs\n");
fprintf(stderr, "Proceeding without activating any channels\n");
}
if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||
(autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {
fprintf(stderr, "Enabling all channels\n");
ret = enable_disable_all_channels(dev_dir_name, 1);
if (ret) {
fprintf(stderr, "Failed to enable all channels\n");
goto error;
}
/* This flags that we need to disable the channels again */
autochannels = AUTOCHANNELS_ACTIVE;
ret = build_channel_array(dev_dir_name, &channels,
&num_channels);
if (ret) {
fprintf(stderr, "Problem reading scan element "
"information\n"
"diag %s\n", dev_dir_name);
goto error;
}
if (!num_channels) {
fprintf(stderr, "Still no channels after "
"auto-enabling, giving up\n");
goto error;
}
}
if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
fprintf(stderr,
"No channels are enabled, we have nothing to scan.\n");
fprintf(stderr, "Enable channels manually in "
FORMAT_SCAN_ELEMENTS_DIR
"/*_en or pass -a to autoenable channels and "
"try again.\n", dev_dir_name);
ret = -ENOENT;
goto error;
}
/*
* Construct the directory name for the associated buffer.
* As we know that the lis3l02dq has only one buffer this may
* be built rather than found.
*/
ret = asprintf(&buf_dir_name,
"%siio:device%d/buffer", iio_dir, dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error;
}
if (!notrigger) {
printf("%s %s\n", dev_dir_name, trigger_name);
/*
* Set the device trigger to be the data ready trigger found
* above
*/
ret = write_sysfs_string_and_verify("trigger/current_trigger",
dev_dir_name,
trigger_name);
if (ret < 0) {
fprintf(stderr,
"Failed to write current_trigger file\n");
goto error;
}
}
/* Setup ring buffer parameters */
ret = write_sysfs_int("length", buf_dir_name, buf_len);
if (ret < 0)
goto error;
/* Enable the buffer */
ret = write_sysfs_int("enable", buf_dir_name, 1);
if (ret < 0) {
fprintf(stderr,
"Failed to enable buffer: %s\n", strerror(-ret));
goto error;
}
scan_size = size_from_channelarray(channels, num_channels);
data = malloc(scan_size * buf_len);
if (!data) {
ret = -ENOMEM;
goto error;
}
ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error;
}
/* Attempt to open non blocking the access dev */
fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
if (fp == -1) { /* TODO: If it isn't there make the node */
ret = -errno;
fprintf(stderr, "Failed to open %s\n", buffer_access);
goto error;
}
for (j = 0; j < num_loops || num_loops < 0; j++) {
if (!noevents) {
struct pollfd pfd = {
.fd = fp,
.events = POLLIN,
};
ret = poll(&pfd, 1, -1);
if (ret < 0) {
ret = -errno;
goto error;
} else if (ret == 0) {
continue;
}
toread = buf_len;
} else {
usleep(timedelay);
toread = 64;
}
read_size = read(fp, data, toread * scan_size);
if (read_size < 0) {
if (errno == EAGAIN) {
fprintf(stderr, "nothing available\n");
continue;
} else {
break;
}
}
for (i = 0; i < read_size / scan_size; i++)
process_scan(data + scan_size * i, channels,
num_channels);
}
error:
cleanup();
if (fp >= 0 && close(fp) == -1)
perror("Failed to close buffer");
free(buffer_access);
free(data);
free(buf_dir_name);
for (i = num_channels - 1; i >= 0; i--) {
free(channels[i].name);
free(channels[i].generic_name);
}
free(channels);
free(trigger_name);
free(device_name);
free(dev_dir_name);
return ret;
}