Support for changing altsetting

Will probably be suject to later consideration w.r.t. claiming of endpoints

4 files changed, 31 insertions, 0 deletions

diff --git a/libusb/core.c b/libusb/core.c
index 7840b80..a4c01ba 100644
--- a/libusb/core.c
+++ b/libusb/core.c
@@ -508,6 +508,14 @@ API_EXPORTED int libusb_release_interface(struct libusb_device_handle *dev,
 	return usbi_backend->release_interface(dev, iface);
 }
 
+/* FIXME docs */
+API_EXPORTED int libusb_set_interface_altsetting(
+	struct libusb_device_handle *dev, int iface, int altsetting)
+{
+	usbi_dbg("interface %d altsetting %d", iface, altsetting);
+	return usbi_backend->set_interface_altsetting(dev, iface, altsetting);
+}
+
 /** \ingroup lib
  * Initialize libusb. This function must be called before calling any other
  * libusb function.
diff --git a/libusb/libusb.h b/libusb/libusb.h
index 0b29223..4aa0e13 100644
--- a/libusb/libusb.h
+++ b/libusb/libusb.h
@@ -597,6 +597,9 @@ int libusb_release_interface(libusb_device_handle *dev, int iface);
 libusb_device_handle *libusb_open_device_with_vid_pid(uint16_t vendor_id,
 	uint16_t product_id);
 
+int libusb_set_interface_altsetting(libusb_device_handle *dev, int iface,
+	int altsetting);
+
 /* async I/O */
 
 /** \ingroup asyncio
diff --git a/libusb/libusbi.h b/libusb/libusbi.h
index 0ff418b..934fd60 100644
--- a/libusb/libusbi.h
+++ b/libusb/libusbi.h
@@ -239,6 +239,9 @@ struct usbi_os_backend {
 	int (*claim_interface)(struct libusb_device_handle *handle, int iface);
 	int (*release_interface)(struct libusb_device_handle *handle, int iface);
 
+	int (*set_interface_altsetting)(struct libusb_device_handle *handle,
+		int iface, int altsetting);
+
 	void (*destroy_device)(struct libusb_device *dev);
 
 	int (*submit_transfer)(struct usbi_transfer *itransfer);
diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c
index a64a7e7..f173930 100644
--- a/libusb/os/linux_usbfs.c
+++ b/libusb/os/linux_usbfs.c
@@ -408,6 +408,21 @@ static int op_release_interface(struct libusb_device_handle *handle, int iface)
 	return r;
 }
 
+static int op_set_interface(struct libusb_device_handle *handle, int iface,
+	int altsetting)
+{
+	int fd = __device_handle_priv(handle)->fd;
+	struct usbfs_setinterface setintf;
+	int r;
+
+	setintf.interface = iface;
+	setintf.altsetting = altsetting;
+	r = ioctl(fd, IOCTL_USBFS_SETINTF, &setintf);
+	if (r < 0)
+		usbi_err("setintf failed error %d", r);
+	return r;
+}
+
 static void op_destroy_device(struct libusb_device *dev)
 {
 	unsigned char *nodepath = __device_priv(dev)->nodepath;
@@ -572,6 +587,8 @@ const struct usbi_os_backend linux_usbfs_backend = {
 	.claim_interface = op_claim_interface,
 	.release_interface = op_release_interface,
 
+	.set_interface_altsetting = op_set_interface,
+
 	.destroy_device = op_destroy_device,
 
 	.submit_transfer = op_submit_transfer,