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authorkartofen <mladenovnasko0@gmail.com>2025-06-08 23:16:33 +0300
committerkartofen <mladenovnasko0@gmail.com>2025-06-08 23:16:33 +0300
commit227f73622b4576bf21719fcc9ea99416056d8a71 (patch)
tree1ab6d7c0e8dab40aa26def1a2ea6098134e82ea8 /wheel_uhid.c
init, have brushed and brushless sim and gnuplot viz, also some usb hid testingHEADmaster
Diffstat (limited to 'wheel_uhid.c')
-rw-r--r--wheel_uhid.c264
1 files changed, 264 insertions, 0 deletions
diff --git a/wheel_uhid.c b/wheel_uhid.c
new file mode 100644
index 0000000..563125b
--- /dev/null
+++ b/wheel_uhid.c
@@ -0,0 +1,264 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <linux/uhid.h>
+#include <stdint.h>
+
+static unsigned char rdesc[] = {
+ #include "wheel_hid_report_desc.h"
+};
+
+static int uhid_write(int fd, const struct uhid_event *ev)
+{
+ ssize_t ret;
+
+ ret = write(fd, ev, sizeof(*ev));
+ if (ret < 0) {
+ fprintf(stderr, "Cannot write to uhid: %m\n");
+ return -errno;
+ } else if (ret != sizeof(*ev)) {
+ fprintf(stderr, "Wrong size written to uhid: %zd != %zu\n",
+ ret, sizeof(ev));
+ return -EFAULT;
+ } else {
+ return 0;
+ }
+}
+
+static int create(int fd)
+{
+ struct uhid_event ev;
+
+ memset(&ev, 0, sizeof(ev));
+ ev.type = UHID_CREATE;
+ strcpy((char*)ev.u.create.name, "test-uhid-device");
+ ev.u.create.rd_data = rdesc;
+ ev.u.create.rd_size = sizeof(rdesc);
+ ev.u.create.bus = BUS_USB;
+ ev.u.create.vendor = 0x15d9;
+ ev.u.create.product = 0x0a37;
+ ev.u.create.version = 0;
+ ev.u.create.country = 0;
+
+ return uhid_write(fd, &ev);
+}
+
+static void destroy(int fd)
+{
+ struct uhid_event ev;
+
+ memset(&ev, 0, sizeof(ev));
+ ev.type = UHID_DESTROY;
+
+ uhid_write(fd, &ev);
+}
+
+/* This parses raw output reports sent by the kernel to the device. A normal
+ * uhid program shouldn't do this but instead just forward the raw report.
+ * However, for ducomentational purposes, we try to detect LED events here and
+ * print debug messages for it. */
+static void handle_output(struct uhid_event *ev)
+{
+ /* LED messages are adverised via OUTPUT reports; ignore the rest */
+ if (ev->u.output.rtype != UHID_OUTPUT_REPORT)
+ return;
+ /* LED reports have length 2 bytes */
+ if (ev->u.output.size != 2)
+ return;
+ /* first byte is report-id which is 0x02 for LEDs in our rdesc */
+ if (ev->u.output.data[0] != 0x2)
+ return;
+
+ /* print flags payload */
+ fprintf(stderr, "LED output report received with flags %x\n",
+ ev->u.output.data[1]);
+}
+
+static int event(int fd)
+{
+ struct uhid_event ev;
+ ssize_t ret;
+
+ memset(&ev, 0, sizeof(ev));
+ ret = read(fd, &ev, sizeof(ev));
+ if (ret == 0) {
+ fprintf(stderr, "Read HUP on uhid-cdev\n");
+ return -EFAULT;
+ } else if (ret < 0) {
+ fprintf(stderr, "Cannot read uhid-cdev: %m\n");
+ return -errno;
+ } else if (ret != sizeof(ev)) {
+ fprintf(stderr, "Invalid size read from uhid-dev: %zd != %zu\n",
+ ret, sizeof(ev));
+ return -EFAULT;
+ }
+
+ switch (ev.type) {
+ case UHID_START:
+ fprintf(stderr, "UHID_START from uhid-dev\n");
+ break;
+ case UHID_STOP:
+ fprintf(stderr, "UHID_STOP from uhid-dev\n");
+ break;
+ case UHID_OPEN:
+ fprintf(stderr, "UHID_OPEN from uhid-dev\n");
+ break;
+ case UHID_CLOSE:
+ fprintf(stderr, "UHID_CLOSE from uhid-dev\n");
+ break;
+ case UHID_OUTPUT:
+ fprintf(stderr, "UHID_OUTPUT from uhid-dev\n");
+ handle_output(&ev);
+ break;
+ case UHID_OUTPUT_EV:
+ fprintf(stderr, "UHID_OUTPUT_EV from uhid-dev\n");
+ break;
+ default:
+ fprintf(stderr, "Invalid event from uhid-dev: %u\n", ev.type);
+ }
+
+ return 0;
+}
+
+struct my_report {
+ uint8_t reportid;
+ int8_t a[4];
+ uint16_t rest;
+} __attribute__((packed)) r = {1};
+
+static int send_event(int fd)
+{
+ struct uhid_event ev;
+
+ memset(&ev, 0, sizeof(ev));
+ ev.type = UHID_INPUT;
+ ev.u.input.size = sizeof(r);
+ memcpy(ev.u.input.data, &r, sizeof(r));
+
+ printf("\n");
+ for(size_t i = 0; i < sizeof(r); i++) {
+ printf("0x%x ", ev.u.input.data[i]);
+ }
+ printf("\n");
+
+ printf("Sending event\n");
+ return uhid_write(fd, &ev);
+}
+
+static int keyboard(int fd)
+{
+ static int axisidx = 0;
+ char buf[128];
+
+ ssize_t ret = read(STDIN_FILENO, buf, sizeof(buf));
+ if (ret == 0) {
+ fprintf(stderr, "Read HUP on stdin\n");
+ return -EFAULT;
+ } else if (ret < 0) {
+ fprintf(stderr, "Cannot read stdin: %m\n");
+ return -errno;
+ }
+
+ for(size_t i = 0; i < ret; ++i) {
+ if(buf[i] >= '1' && buf[i] <= '8') {
+ axisidx = buf[i] - '0' - 1;
+ continue;
+ }
+
+ switch(buf[i]) {
+ case 'u': r.a[axisidx] += 2; send_event(fd); break;
+ case 'd': r.a[axisidx] -= 2; send_event(fd); break;
+ case 'q': return -ECANCELED;
+ default:
+ fprintf(stderr, "Unknown command %c\n", buf[i]);
+ }
+ }
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int fd;
+ const char *path = "/dev/uhid";
+ struct pollfd pfds[2];
+ int ret;
+ struct termios state;
+
+ ret = tcgetattr(STDIN_FILENO, &state);
+ if (ret) {
+ fprintf(stderr, "Cannot get tty state\n");
+ } else {
+ state.c_lflag &= ~ICANON;
+ state.c_cc[VMIN] = 1;
+ ret = tcsetattr(STDIN_FILENO, TCSANOW, &state);
+ if (ret)
+ fprintf(stderr, "Cannot set tty state\n");
+ }
+
+ if (argc >= 2) {
+ if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
+ fprintf(stderr, "Usage: %s [%s]\n", argv[0], path);
+ return EXIT_SUCCESS;
+ } else {
+ path = argv[1];
+ }
+ }
+
+ fprintf(stderr, "Open uhid-cdev %s\n", path);
+ fd = open(path, O_RDWR | O_CLOEXEC);
+ if (fd < 0) {
+ fprintf(stderr, "Cannot open uhid-cdev %s: %m\n", path);
+ return EXIT_FAILURE;
+ }
+
+ fprintf(stderr, "Create uhid device\n");
+ ret = create(fd);
+ if (ret) {
+ close(fd);
+ return EXIT_FAILURE;
+ }
+
+ pfds[0].fd = STDIN_FILENO;
+ pfds[0].events = POLLIN;
+ pfds[1].fd = fd;
+ pfds[1].events = POLLIN;
+
+ fprintf(stderr, "Press 'q' to quit...\n");
+ while (1) {
+ ret = poll(pfds, 2, -1);
+ if (ret < 0) {
+ fprintf(stderr, "Cannot poll for fds: %m\n");
+ break;
+ }
+ if (pfds[0].revents & POLLHUP) {
+ fprintf(stderr, "Received HUP on stdin\n");
+ break;
+ }
+ if (pfds[1].revents & POLLHUP) {
+ fprintf(stderr, "Received HUP on uhid-cdev\n");
+ break;
+ }
+
+ if (pfds[0].revents & POLLIN) {
+ ret = keyboard(fd);
+ if (ret)
+ break;
+ }
+ if (pfds[1].revents & POLLIN) {
+ ret = event(fd);
+ if (ret)
+ break;
+ }
+ }
+
+ fprintf(stderr, "Destroy uhid device\n");
+ destroy(fd);
+ return EXIT_SUCCESS;
+}