// SPDX-License-Identifier: GPL-2.0
/*
* GPIO mockup cdev test helper
*
* Copyright (C) 2020 Kent Gibson
*/
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/gpio.h>
#define CONSUMER "gpio-mockup-cdev"
static int request_line_v2(int cfd, unsigned int offset,
uint64_t flags, unsigned int val)
{
struct gpio_v2_line_request req;
int ret;
memset(&req, 0, sizeof(req));
req.num_lines = 1;
req.offsets[0] = offset;
req.config.flags = flags;
strcpy(req.consumer, CONSUMER);
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
req.config.num_attrs = 1;
req.config.attrs[0].mask = 1;
req.config.attrs[0].attr.id = GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES;
if (val)
req.config.attrs[0].attr.values = 1;
}
ret = ioctl(cfd, GPIO_V2_GET_LINE_IOCTL, &req);
if (ret == -1)
return -errno;
return req.fd;
}
static int get_value_v2(int lfd)
{
struct gpio_v2_line_values vals;
int ret;
memset(&vals, 0, sizeof(vals));
vals.mask = 1;
ret = ioctl(lfd, GPIO_V2_LINE_GET_VALUES_IOCTL, &vals);
if (ret == -1)
return -errno;
return vals.bits & 0x1;
}
static int request_line_v1(int cfd, unsigned int offset,
uint32_t flags, unsigned int val)
{
struct gpiohandle_request req;
int ret;
memset(&req, 0, sizeof(req));
req.lines = 1;
req.lineoffsets[0] = offset;
req.flags = flags;
strcpy(req.consumer_label, CONSUMER);
if (flags & GPIOHANDLE_REQUEST_OUTPUT)
req.default_values[0] = val;
ret = ioctl(cfd, GPIO_GET_LINEHANDLE_IOCTL, &req);
if (ret == -1)
return -errno;
return req.fd;
}
static int get_value_v1(int lfd)
{
struct gpiohandle_data vals;
int ret;
memset(&vals, 0, sizeof(vals));
ret = ioctl(lfd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &vals);
if (ret == -1)
return -errno;
return vals.values[0];
}
static void usage(char *prog)
{
printf("Usage: %s [-l] [-b <bias>] [-s <value>] [-u <uAPI>] <gpiochip> <offset>\n", prog);
printf(" -b: set line bias to one of pull-down, pull-up, disabled\n");
printf(" (default is to leave bias unchanged):\n");
printf(" -l: set line active low (default is active high)\n");
printf(" -s: set line value (default is to get line value)\n");
printf(" -u: uAPI version to use (default is 2)\n");
exit(-1);
}
static int wait_signal(void)
{
int sig;
sigset_t wset;
sigemptyset(&wset);
sigaddset(&wset, SIGHUP);
sigaddset(&wset, SIGINT);
sigaddset(&wset, SIGTERM);
sigwait(&wset, &sig);
return sig;
}
int main(int argc, char *argv[])
{
char *chip;
int opt, ret, cfd, lfd;
unsigned int offset, val = 0, abiv;
uint32_t flags_v1;
uint64_t flags_v2;
abiv = 2;
ret = 0;
flags_v1 = GPIOHANDLE_REQUEST_INPUT;
flags_v2 = GPIO_V2_LINE_FLAG_INPUT;
while ((opt = getopt(argc, argv, "lb:s:u:")) != -1) {
switch (opt) {
case 'l':
flags_v1 |= GPIOHANDLE_REQUEST_ACTIVE_LOW;
flags_v2 |= GPIO_V2_LINE_FLAG_ACTIVE_LOW;
break;
case 'b':
if (strcmp("pull-up", optarg) == 0) {
flags_v1 |= GPIOHANDLE_REQUEST_BIAS_PULL_UP;
flags_v2 |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP;
} else if (strcmp("pull-down", optarg) == 0) {
flags_v1 |= GPIOHANDLE_REQUEST_BIAS_PULL_DOWN;
flags_v2 |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN;
} else if (strcmp("disabled", optarg) == 0) {
flags_v1 |= GPIOHANDLE_REQUEST_BIAS_DISABLE;
flags_v2 |= GPIO_V2_LINE_FLAG_BIAS_DISABLED;
}
break;
case 's':
val = atoi(optarg);
flags_v1 &= ~GPIOHANDLE_REQUEST_INPUT;
flags_v1 |= GPIOHANDLE_REQUEST_OUTPUT;
flags_v2 &= ~GPIO_V2_LINE_FLAG_INPUT;
flags_v2 |= GPIO_V2_LINE_FLAG_OUTPUT;
break;
case 'u':
abiv = atoi(optarg);
break;
default:
usage(argv[0]);
}
}
if (argc < optind + 2)
usage(argv[0]);
chip = argv[optind];
offset = atoi(argv[optind + 1]);
cfd = open(chip, 0);
if (cfd == -1) {
fprintf(stderr, "Failed to open %s: %s\n", chip, strerror(errno));
return -errno;
}
if (abiv == 1)
lfd = request_line_v1(cfd, offset, flags_v1, val);
else
lfd = request_line_v2(cfd, offset, flags_v2, val);
close(cfd);
if (lfd < 0) {
fprintf(stderr, "Failed to request %s:%d: %s\n", chip, offset, strerror(-lfd));
return lfd;
}
if (flags_v2 & GPIO_V2_LINE_FLAG_OUTPUT) {
wait_signal();
} else {
if (abiv == 1)
ret = get_value_v1(lfd);
else
ret = get_value_v2(lfd);
}
close(lfd);
return ret;
}