HID: Documentation for hidraw
Documenation for the hidraw driver, with sample program.
Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/samples/hidraw/hid-example.c b/samples/hidraw/hid-example.c
new file mode 100644
index 0000000..40e3d62
--- /dev/null
+++ b/samples/hidraw/hid-example.c
@@ -0,0 +1,167 @@
+/*
+ * Hidraw Userspace Example
+ *
+ * Copyright (c) 2010 Alan Ott <alan@signal11.us>
+ * Copyright (c) 2010 Signal 11 Software
+ *
+ * The code may be used by anyone for any purpose,
+ * and can serve as a starting point for developing
+ * applications using hidraw.
+ */
+
+/* Linux */
+#include <linux/types.h>
+#include <linux/input.h>
+#include <linux/hidraw.h>
+
+/* Unix */
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/* C */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+
+const char *bus_str(int bus);
+
+int main(int argc, char **argv)
+{
+ int fd;
+ int i, res, desc_size = 0;
+ char buf[256];
+ struct hidraw_report_descriptor rpt_desc;
+ struct hidraw_devinfo info;
+
+ /* Open the Device with non-blocking reads. In real life,
+ don't use a hard coded path; use libudev instead. */
+ fd = open("/dev/hidraw0", O_RDWR|O_NONBLOCK);
+
+ if (fd < 0) {
+ perror("Unable to open device");
+ return 1;
+ }
+
+ memset(&rpt_desc, 0x0, sizeof(rpt_desc));
+ memset(&info, 0x0, sizeof(info));
+ memset(buf, 0x0, sizeof(buf));
+
+ /* Get Report Descriptor Size */
+ res = ioctl(fd, HIDIOCGRDESCSIZE, &desc_size);
+ if (res < 0)
+ perror("HIDIOCGRDESCSIZE");
+ else
+ printf("Report Descriptor Size: %d\n", desc_size);
+
+ /* Get Report Descriptor */
+ rpt_desc.size = desc_size;
+ res = ioctl(fd, HIDIOCGRDESC, &rpt_desc);
+ if (res < 0) {
+ perror("HIDIOCGRDESC");
+ } else {
+ printf("Report Descriptor:\n");
+ for (i = 0; i < rpt_desc.size; i++)
+ printf("%hhx ", rpt_desc.value[i]);
+ puts("\n");
+ }
+
+ /* Get Raw Name */
+ res = ioctl(fd, HIDIOCGRAWNAME(256), buf);
+ if (res < 0)
+ perror("HIDIOCGRAWNAME");
+ else
+ printf("Raw Name: %s\n", buf);
+
+ /* Get Physical Location */
+ res = ioctl(fd, HIDIOCGRAWPHYS(256), buf);
+ if (res < 0)
+ perror("HIDIOCGRAWPHYS");
+ else
+ printf("Raw Phys: %s\n", buf);
+
+ /* Get Raw Info */
+ res = ioctl(fd, HIDIOCGRAWINFO, &info);
+ if (res < 0) {
+ perror("HIDIOCGRAWINFO");
+ } else {
+ printf("Raw Info:\n");
+ printf("\tbustype: %d (%s)\n",
+ info.bustype, bus_str(info.bustype));
+ printf("\tvendor: 0x%04hx\n", info.vendor);
+ printf("\tproduct: 0x%04hx\n", info.product);
+ }
+
+ /* Set Feature */
+ buf[0] = 0x9; /* Report Number */
+ buf[1] = 0xff;
+ buf[2] = 0xff;
+ buf[3] = 0xff;
+ res = ioctl(fd, HIDIOCSFEATURE(4), buf);
+ if (res < 0)
+ perror("HIDIOCSFEATURE");
+ else
+ printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
+
+ /* Get Feature */
+ buf[0] = 0x9; /* Report Number */
+ res = ioctl(fd, HIDIOCGFEATURE(256), buf);
+ if (res < 0) {
+ perror("HIDIOCGFEATURE");
+ } else {
+ printf("ioctl HIDIOCGFEATURE returned: %d\n", res);
+ printf("Report data (not containing the report number):\n\t");
+ for (i = 0; i < res; i++)
+ printf("%hhx ", buf[i]);
+ puts("\n");
+ }
+
+ /* Send a Report to the Device */
+ buf[0] = 0x1; /* Report Number */
+ buf[1] = 0x77;
+ res = write(fd, buf, 2);
+ if (res < 0) {
+ printf("Error: %d\n", errno);
+ perror("write");
+ } else {
+ printf("write() wrote %d bytes\n", res);
+ }
+
+ /* Get a report from the device */
+ res = read(fd, buf, 16);
+ if (res < 0) {
+ perror("read");
+ } else {
+ printf("read() read %d bytes:\n\t", res);
+ for (i = 0; i < res; i++)
+ printf("%hhx ", buf[i]);
+ puts("\n");
+ }
+ close(fd);
+ return 0;
+}
+
+const char *
+bus_str(int bus)
+{
+ switch (bus) {
+ case BUS_USB:
+ return "USB";
+ break;
+ case BUS_HIL:
+ return "HIL";
+ break;
+ case BUS_BLUETOOTH:
+ return "Bluetooth";
+ break;
+ case BUS_VIRTUAL:
+ return "Virtual";
+ break;
+ default:
+ return "Other";
+ break;
+ }
+}