/*
 * gpio-hammer - example swiss army knife to shake GPIO lines on a system
 *
 * Copyright (C) 2016 Linus Walleij
 *
 * 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.
 *
 * Usage:
 *	gpio-hammer -n <device-name> -o <offset1> -o <offset2>
 */

#include <unistd.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <poll.h>
#include <fcntl.h>
#include <getopt.h>
#include <sys/ioctl.h>
#include <linux/gpio.h>
#include "gpio-utils.h"

int hammer_device(const char *device_name, unsigned int *lines, int nlines,
		  unsigned int loops)
{
	struct gpiohandle_data data;
	char swirr[] = "-\\|/";
	int fd;
	int ret;
	int i, j;
	unsigned int iteration = 0;

	memset(&data.values, 0, sizeof(data.values));
	ret = gpiotools_request_linehandle(device_name, lines, nlines,
					   GPIOHANDLE_REQUEST_OUTPUT, &data,
					   "gpio-hammler");
	if (ret < 0)
		goto exit_error;
	else
		fd = ret;

	ret = gpiotools_get_values(fd, &data);
	if (ret < 0)
		goto exit_close_error;

	fprintf(stdout, "Hammer lines [");
	for (i = 0; i < nlines; i++) {
		fprintf(stdout, "%d", lines[i]);
		if (i != (nlines - 1))
			fprintf(stdout, ", ");
	}
	fprintf(stdout, "] on %s, initial states: [", device_name);
	for (i = 0; i < nlines; i++) {
		fprintf(stdout, "%d", data.values[i]);
		if (i != (nlines - 1))
			fprintf(stdout, ", ");
	}
	fprintf(stdout, "]\n");

	/* Hammertime! */
	j = 0;
	while (1) {
		/* Invert all lines so we blink */
		for (i = 0; i < nlines; i++)
			data.values[i] = !data.values[i];

		ret = gpiotools_set_values(fd, &data);
		if (ret < 0)
			goto exit_close_error;

		/* Re-read values to get status */
		ret = gpiotools_get_values(fd, &data);
		if (ret < 0)
			goto exit_close_error;

		fprintf(stdout, "[%c] ", swirr[j]);
		j++;
		if (j == sizeof(swirr)-1)
			j = 0;

		fprintf(stdout, "[");
		for (i = 0; i < nlines; i++) {
			fprintf(stdout, "%d: %d", lines[i], data.values[i]);
			if (i != (nlines - 1))
				fprintf(stdout, ", ");
		}
		fprintf(stdout, "]\r");
		fflush(stdout);
		sleep(1);
		iteration++;
		if (loops && iteration == loops)
			break;
	}
	fprintf(stdout, "\n");
	ret = 0;

exit_close_error:
	gpiotools_release_linehandle(fd);
exit_error:
	return ret;
}

void print_usage(void)
{
	fprintf(stderr, "Usage: gpio-hammer [options]...\n"
		"Hammer GPIO lines, 0->1->0->1...\n"
		"  -n <name>  Hammer GPIOs on a named device (must be stated)\n"
		"  -o <n>     Offset[s] to hammer, at least one, several can be stated\n"
		" [-c <n>]    Do <n> loops (optional, infinite loop if not stated)\n"
		"  -?         This helptext\n"
		"\n"
		"Example:\n"
		"gpio-hammer -n gpiochip0 -o 4\n"
	);
}

int main(int argc, char **argv)
{
	const char *device_name = NULL;
	unsigned int lines[GPIOHANDLES_MAX];
	unsigned int loops = 0;
	int nlines;
	int c;
	int i;

	i = 0;
	while ((c = getopt(argc, argv, "c:n:o:?")) != -1) {
		switch (c) {
		case 'c':
			loops = strtoul(optarg, NULL, 10);
			break;
		case 'n':
			device_name = optarg;
			break;
		case 'o':
			lines[i] = strtoul(optarg, NULL, 10);
			i++;
			break;
		case '?':
			print_usage();
			return -1;
		}
	}
	nlines = i;

	if (!device_name || !nlines) {
		print_usage();
		return -1;
	}
	return hammer_device(device_name, lines, nlines, loops);
}
on value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Theodore Ts'o &lt;tytso@mit.edu&gt;</td><td class='right'>2016-04-23 22:50:07 -0400</td></tr>
<tr><th>committer</th><td>Theodore Ts'o &lt;tytso@mit.edu&gt;</td><td class='right'>2016-04-23 22:50:07 -0400</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Documentation?id=1f60fbe7274918adb8db2f616e321890730ab7e3'>1f60fbe7274918adb8db2f616e321890730ab7e3</a> (<a href='/cgit.cgi/linux/net-next.git/patch/Documentation?id=1f60fbe7274918adb8db2f616e321890730ab7e3'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=1f60fbe7274918adb8db2f616e321890730ab7e3'>4e41c7a0fd5204cad9e651baa23207bf4dafe256</a> /<a href='/cgit.cgi/linux/net-next.git/tree/Documentation?id=1f60fbe7274918adb8db2f616e321890730ab7e3'>Documentation</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/Documentation?id=c3b46c73264b03000d1e18b22f5caf63332547c9'>c3b46c73264b03000d1e18b22f5caf63332547c9</a> (<a href='/cgit.cgi/linux/net-next.git/diff/Documentation?id=1f60fbe7274918adb8db2f616e321890730ab7e3&amp;id2=c3b46c73264b03000d1e18b22f5caf63332547c9'>diff</a>)</td></tr></table>
<div class='commit-subject'>ext4: allow readdir()'s of large empty directories to be interrupted</div><div class='commit-msg'>If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to scheduler warnings and users
getting irritated when they can't kill a process in the middle of one
of these long-running readdir operations.  Fix this by adding checks to
ext4_readdir() and ext4_htree_fill_tree().

This was reverted earlier due to a typo in the original commit where I
experimented with using signal_pending() instead of
fatal_signal_pending().  The test was in the wrong place if we were
going to return signal_pending() since we would end up returning
duplicant entries.  See 9f2394c9be47 for a more detailed explanation.

Added fix as suggested by Linus to check for signal_pending() in
in the filldir() functions.

Reported-by: Benjamin LaHaise &lt;bcrl@kvack.org&gt;
Google-Bug-Id: 27880676
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=1f60fbe7274918adb8db2f616e321890730ab7e3'>Diffstat</a> (limited to 'Documentation')</div><table summary='diffstat' class='diffstat'>