1 /*
2 * Copyright 2023 Google LLC
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <linux/input.h>
10 #include <nsi_tracing.h>
11 #include <string.h>
12 #include <unistd.h>
13
14 #include "linux_evdev_bottom.h"
15
linux_evdev_read(int fd,uint16_t * type,uint16_t * code,int32_t * value)16 int linux_evdev_read(int fd, uint16_t *type, uint16_t *code, int32_t *value)
17 {
18 struct input_event ev;
19 int ret;
20
21 ret = read(fd, &ev, sizeof(ev));
22 if (ret < 0) {
23 if (errno == EAGAIN || errno == EINTR) {
24 return NATIVE_LINUX_EVDEV_NO_DATA;
25 }
26 nsi_print_warning("Read error: %s", strerror(errno));
27 return -EIO;
28 } else if (ret < sizeof(ev)) {
29 nsi_print_warning("Unexpected read size: %d, expecting %d",
30 ret, sizeof(ev));
31 return -EIO;
32 }
33
34 *type = ev.type;
35 *code = ev.code;
36 *value = ev.value;
37
38 return 0;
39 }
40
linux_evdev_open(const char * path)41 int linux_evdev_open(const char *path)
42 {
43 int fd;
44
45 fd = open(path, O_RDONLY | O_NONBLOCK);
46 if (fd < 0) {
47 nsi_print_error_and_exit(
48 "Failed to open the evdev device %s: %s\n",
49 path, strerror(errno));
50 }
51
52 return fd;
53 }
54
