diff --git a/samples/uhid/Makefile b/samples/uhid/Makefile new file mode 100644 index 0000000..c95a696 --- /dev/null +++ b/samples/uhid/Makefile @@ -0,0 +1,10 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := uhid-example + +# Tell kbuild to always build the programs +always := $(hostprogs-y) + +HOSTCFLAGS_uhid-example.o += -I$(objtree)/usr/include diff --git a/samples/uhid/uhid-example.c b/samples/uhid/uhid-example.c new file mode 100644 index 0000000..03ce3c0 --- /dev/null +++ b/samples/uhid/uhid-example.c @@ -0,0 +1,381 @@ +/* + * UHID Example + * + * Copyright (c) 2012 David Herrmann + * + * The code may be used by anyone for any purpose, + * and can serve as a starting point for developing + * applications using uhid. + */ + +/* UHID Example + * This example emulates a basic 3 buttons mouse with wheel over UHID. Run this + * program as root and then use the following keys to control the mouse: + * q: Quit the application + * 1: Toggle left button (down, up, ...) + * 2: Toggle right button + * 3: Toggle middle button + * a: Move mouse left + * d: Move mouse right + * w: Move mouse up + * s: Move mouse down + * r: Move wheel up + * f: Move wheel down + * + * If uhid is not available as /dev/uhid, then you can pass a different path as + * first argument. + * If is not installed in /usr, then compile this with: + * gcc -o ./uhid_test -Wall -I./include ./samples/uhid/uhid-example.c + * And ignore the warning about kernel headers. However, it is recommended to + * use the installed uhid.h if available. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* HID Report Desciptor + * We emulate a basic 3 button mouse with wheel. This is the report-descriptor + * as the kernel will parse it: + * + * INPUT[INPUT] + * Field(0) + * Physical(GenericDesktop.Pointer) + * Application(GenericDesktop.Mouse) + * Usage(3) + * Button.0001 + * Button.0002 + * Button.0003 + * Logical Minimum(0) + * Logical Maximum(1) + * Report Size(1) + * Report Count(3) + * Report Offset(0) + * Flags( Variable Absolute ) + * Field(1) + * Physical(GenericDesktop.Pointer) + * Application(GenericDesktop.Mouse) + * Usage(3) + * GenericDesktop.X + * GenericDesktop.Y + * GenericDesktop.Wheel + * Logical Minimum(-128) + * Logical Maximum(127) + * Report Size(8) + * Report Count(3) + * Report Offset(8) + * Flags( Variable Relative ) + * + * This is the mapping that we expect: + * Button.0001 ---> Key.LeftBtn + * Button.0002 ---> Key.RightBtn + * Button.0003 ---> Key.MiddleBtn + * GenericDesktop.X ---> Relative.X + * GenericDesktop.Y ---> Relative.Y + * GenericDesktop.Wheel ---> Relative.Wheel + * + * This information can be verified by reading /sys/kernel/debug/hid//rdesc + * This file should print the same information as showed above. + */ + +static unsigned char rdesc[] = { + 0x05, 0x01, 0x09, 0x02, 0xa1, 0x01, 0x09, 0x01, + 0xa1, 0x00, 0x05, 0x09, 0x19, 0x01, 0x29, 0x03, + 0x15, 0x00, 0x25, 0x01, 0x95, 0x03, 0x75, 0x01, + 0x81, 0x02, 0x95, 0x01, 0x75, 0x05, 0x81, 0x01, + 0x05, 0x01, 0x09, 0x30, 0x09, 0x31, 0x09, 0x38, + 0x15, 0x80, 0x25, 0x7f, 0x75, 0x08, 0x95, 0x03, + 0x81, 0x06, 0xc0, 0xc0, +}; + +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: %ld != %lu\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); +} + +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: %ld != %lu\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"); + 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; +} + +static bool btn1_down; +static bool btn2_down; +static bool btn3_down; +static signed char abs_hor; +static signed char abs_ver; +static signed char wheel; + +static int send_event(int fd) +{ + struct uhid_event ev; + + memset(&ev, 0, sizeof(ev)); + ev.type = UHID_INPUT; + ev.u.input.size = 4; + + if (btn1_down) + ev.u.input.data[0] |= 0x1; + if (btn2_down) + ev.u.input.data[0] |= 0x2; + if (btn3_down) + ev.u.input.data[0] |= 0x4; + + ev.u.input.data[1] = abs_hor; + ev.u.input.data[2] = abs_ver; + ev.u.input.data[3] = wheel; + + return uhid_write(fd, &ev); +} + +static int keyboard(int fd) +{ + char buf[128]; + ssize_t ret, i; + + 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 (i = 0; i < ret; ++i) { + switch (buf[i]) { + case '1': + btn1_down = !btn1_down; + ret = send_event(fd); + if (ret) + return ret; + break; + case '2': + btn2_down = !btn2_down; + ret = send_event(fd); + if (ret) + return ret; + break; + case '3': + btn3_down = !btn3_down; + ret = send_event(fd); + if (ret) + return ret; + break; + case 'a': + abs_hor = -20; + ret = send_event(fd); + abs_hor = 0; + if (ret) + return ret; + break; + case 'd': + abs_hor = 20; + ret = send_event(fd); + abs_hor = 0; + if (ret) + return ret; + break; + case 'w': + abs_ver = -20; + ret = send_event(fd); + abs_ver = 0; + if (ret) + return ret; + break; + case 's': + abs_ver = 20; + ret = send_event(fd); + abs_ver = 0; + if (ret) + return ret; + break; + case 'r': + wheel = 1; + ret = send_event(fd); + wheel = 0; + if (ret) + return ret; + break; + case 'f': + wheel = -1; + ret = send_event(fd); + wheel = 0; + if (ret) + return ret; + break; + case 'q': + return -ECANCELED; + default: + fprintf(stderr, "Invalid input: %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; +}