/*
 * lsgpio - example on how to list the GPIO lines on a system
 *
 * Copyright (C) 2015 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:
 *	lsgpio <-n device-name>
 */

#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"

struct gpio_flag {
	char *name;
	unsigned long mask;
};

struct gpio_flag flagnames[] = {
	{
		.name = "kernel",
		.mask = GPIOLINE_FLAG_KERNEL,
	},
	{
		.name = "output",
		.mask = GPIOLINE_FLAG_IS_OUT,
	},
	{
		.name = "active-low",
		.mask = GPIOLINE_FLAG_ACTIVE_LOW,
	},
	{
		.name = "open-drain",
		.mask = GPIOLINE_FLAG_OPEN_DRAIN,
	},
	{
		.name = "open-source",
		.mask = GPIOLINE_FLAG_OPEN_SOURCE,
	},
};

void print_flags(unsigned long flags)
{
	int i;
	int printed = 0;

	for (i = 0; i < ARRAY_SIZE(flagnames); i++) {
		if (flags & flagnames[i].mask) {
			if (printed)
				fprintf(stdout, " ");
			fprintf(stdout, "%s", flagnames[i].name);
			printed++;
		}
	}
}

int list_device(const char *device_name)
{
	struct gpiochip_info cinfo;
	char *chrdev_name;
	int fd;
	int ret;
	int i;

	ret = asprintf(&chrdev_name, "/dev/%s", device_name);
	if (ret < 0)
		return -ENOMEM;

	fd = open(chrdev_name, 0);
	if (fd == -1) {
		ret = -errno;
		fprintf(stderr, "Failed to open %s\n", chrdev_name);
		goto exit_close_error;
	}

	/* Inspect this GPIO chip */
	ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo);
	if (ret == -1) {
		ret = -errno;
		perror("Failed to issue CHIPINFO IOCTL\n");
		goto exit_close_error;
	}
	fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n",
		cinfo.name, cinfo.label, cinfo.lines);

	/* Loop over the lines and print info */
	for (i = 0; i < cinfo.lines; i++) {
		struct gpioline_info linfo;

		memset(&linfo, 0, sizeof(linfo));
		linfo.line_offset = i;

		ret = ioctl(fd, GPIO_GET_LINEINFO_IOCTL, &linfo);
		if (ret == -1) {
			ret = -errno;
			perror("Failed to issue LINEINFO IOCTL\n");
			goto exit_close_error;
		}
		fprintf(stdout, "\tline %2d:", linfo.line_offset);
		if (linfo.name[0])
			fprintf(stdout, " \"%s\"", linfo.name);
		else
			fprintf(stdout, " unnamed");
		if (linfo.consumer[0])
			fprintf(stdout, " \"%s\"", linfo.consumer);
		else
			fprintf(stdout, " unused");
		if (linfo.flags) {
			fprintf(stdout, " [");
			print_flags(linfo.flags);
			fprintf(stdout, "]");
		}
		fprintf(stdout, "\n");

	}

exit_close_error:
	if (close(fd) == -1)
		perror("Failed to close GPIO character device file");
	free(chrdev_name);
	return ret;
}

void print_usage(void)
{
	fprintf(stderr, "Usage: lsgpio [options]...\n"
		"List GPIO chips, lines and states\n"
		"  -n <name>  List GPIOs on a named device\n"
		"  -?         This helptext\n"
	);
}

int main(int argc, char **argv)
{
	const char *device_name = NULL;
	int ret;
	int c;

	while ((c = getopt(argc, argv, "n:")) != -1) {
		switch (c) {
		case 'n':
			device_name = optarg;
			break;
		case '?':
			print_usage();
			return -1;
		}
	}

	if (device_name)
		ret = list_device(device_name);
	else {
		const struct dirent *ent;
		DIR *dp;

		/* List all GPIO devices one at a time */
		dp = opendir("/dev");
		if (!dp) {
			ret = -errno;
			goto error_out;
		}

		ret = -ENOENT;
		while (ent = readdir(dp), ent) {
			if (check_prefix(ent->d_name, "gpiochip")) {
				ret = list_device(ent->d_name);
				if (ret)
					break;
			}
		}

		ret = 0;
		if (closedir(dp) == -1) {
			perror("scanning devices: Failed to close directory");
			ret = -errno;
		}
	}
error_out:
	return ret;
}
ption value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option 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>Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;</td><td class='right'>2017-02-03 14:18:39 -0800</td></tr>
<tr><th>committer</th><td>Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;</td><td class='right'>2017-02-04 00:11:08 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/dccp/qpolicy.c?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>6e978b22efa1db9f6e71b24440b5f1d93e968ee3</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/dccp/qpolicy.c?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>c666f7a26b860674848949e39a610222b0723f89</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/dccp/qpolicy.c?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>net/dccp/qpolicy.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/dccp/qpolicy.c?h=nds-private-remove&amp;id=3c223c19aea85d3dda1416c187915f4a30b04b1f'>3c223c19aea85d3dda1416c187915f4a30b04b1f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/dccp/qpolicy.c?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3&amp;id2=3c223c19aea85d3dda1416c187915f4a30b04b1f'>diff</a>)</td></tr></table>
<div class='commit-subject'>cpufreq: intel_pstate: Disable energy efficiency optimization</div><div class='commit-msg'>Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.

This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.

It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.

On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.

Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.

There are several ways to address this problem.

First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.

Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.

Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".

Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.

Signed-off-by: Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;
Reviewed-by: Len Brown &lt;len.brown@intel.com&gt;
Cc: 4.6+ &lt;stable@vger.kernel.org&gt; # 4.6+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>Diffstat</a> (limited to 'net/dccp/qpolicy.c')</div><table summary='diffstat' class='diffstat'>