From c1fa2306181924ebd8b36b0e3910b7904143beb8 Mon Sep 17 00:00:00 2001
From: Dean Camera <dean@fourwalledcubicle.com>
Date: Sun, 6 Dec 2009 13:37:30 +0000
Subject: Add new USB_Host_GetDeviceStringDescriptor() convenience function.

---
 LUFA/Drivers/USB/LowLevel/Host.c | 16 ++++++++++++++++
 LUFA/Drivers/USB/LowLevel/Host.h | 16 ++++++++++++++++
 2 files changed, 32 insertions(+)

(limited to 'LUFA/Drivers/USB')

diff --git a/LUFA/Drivers/USB/LowLevel/Host.c b/LUFA/Drivers/USB/LowLevel/Host.c
index 98185a487..e10d34781 100644
--- a/LUFA/Drivers/USB/LowLevel/Host.c
+++ b/LUFA/Drivers/USB/LowLevel/Host.c
@@ -308,6 +308,22 @@ uint8_t USB_Host_GetDeviceDescriptor(void* const DeviceDescriptorPtr)
 	return USB_Host_SendControlRequest(DeviceDescriptorPtr);
 }
 
+uint8_t USB_Host_GetDeviceStringDescriptor(uint8_t Index, void* const Buffer, uint8_t BufferLength)
+{
+	USB_ControlRequest = (USB_Request_Header_t)
+		{
+			bmRequestType: (REQDIR_DEVICETOHOST | REQTYPE_STANDARD | REQREC_DEVICE),
+			bRequest:      REQ_GetDescriptor,
+			wValue:        (DTYPE_String << 8) | Index,
+			wIndex:        0,
+			wLength:       BufferLength,
+		};
+
+	Pipe_SelectPipe(PIPE_CONTROLPIPE);
+	
+	return USB_Host_SendControlRequest(Buffer);
+}
+
 uint8_t USB_Host_ClearPipeStall(uint8_t EndpointNum)
 {
 	if (Pipe_GetPipeToken() == PIPE_TOKEN_IN)
diff --git a/LUFA/Drivers/USB/LowLevel/Host.h b/LUFA/Drivers/USB/LowLevel/Host.h
index 8cf1fe047..0a0700210 100644
--- a/LUFA/Drivers/USB/LowLevel/Host.h
+++ b/LUFA/Drivers/USB/LowLevel/Host.h
@@ -201,6 +201,22 @@
 			 */
 			uint8_t USB_Host_GetDeviceDescriptor(void* const DeviceDescriptorPtr);
 			
+			/** Convenience function. This routine sends a GetDescriptor standard request to the attached
+			 *  device, requesting the string descriptor of the specified index. This can be used to easily
+			 *  retrieve string descriptors from the device by index, after the index is obtained from the
+			 *  Device or Configuration descriptors.
+			 *
+			 *  \note After this routine returns, the control pipe will be selected.
+			 *
+			 *  \param[in] Index  Index of the string index to retrieve
+			 *  \param[out] Buffer  Pointer to the destination buffer where the retrieved string decriptor is
+			 *                      to be stored
+			 *  \param[in] BufferLength  Maximum size of the string descriptor which can be stored into the buffer
+			 *
+			 *  \return A value from the \ref USB_Host_SendControlErrorCodes_t enum to indicate the result.
+			 */
+			uint8_t USB_Host_GetDeviceStringDescriptor(uint8_t Index, void* const Buffer, uint8_t BufferLength);
+			
 			/** Clears a stall condition on the given pipe, via a ClearFeature request to the attached device.
 			 *
 			 *  \note After this routine returns, the control pipe will be selected.
-- 
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