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Diffstat (limited to 'lib/lufa/Demos/Host/LowLevel/JoystickHostWithParser/HIDReport.c')
-rw-r--r-- | lib/lufa/Demos/Host/LowLevel/JoystickHostWithParser/HIDReport.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/lib/lufa/Demos/Host/LowLevel/JoystickHostWithParser/HIDReport.c b/lib/lufa/Demos/Host/LowLevel/JoystickHostWithParser/HIDReport.c new file mode 100644 index 000000000..dadbb395d --- /dev/null +++ b/lib/lufa/Demos/Host/LowLevel/JoystickHostWithParser/HIDReport.c @@ -0,0 +1,111 @@ +/* + LUFA Library + Copyright (C) Dean Camera, 2017. + + dean [at] fourwalledcubicle [dot] com + www.lufa-lib.org +*/ + +/* + Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com) + + Permission to use, copy, modify, distribute, and sell this + software and its documentation for any purpose is hereby granted + without fee, provided that the above copyright notice appear in + all copies and that both that the copyright notice and this + permission notice and warranty disclaimer appear in supporting + documentation, and that the name of the author not be used in + advertising or publicity pertaining to distribution of the + software without specific, written prior permission. + + The author disclaims all warranties with regard to this + software, including all implied warranties of merchantability + and fitness. In no event shall the author be liable for any + special, indirect or consequential damages or any damages + whatsoever resulting from loss of use, data or profits, whether + in an action of contract, negligence or other tortious action, + arising out of or in connection with the use or performance of + this software. +*/ + +#include "HIDReport.h" + +/** Size in bytes of the attached device's HID report descriptor */ +uint16_t HIDReportSize; + +/** Processed HID report descriptor items structure, containing information on each HID report element */ +HID_ReportInfo_t HIDReportInfo; + + +/** Function to read in the HID report descriptor from the attached device, and process it into easy-to-read + * structures via the HID parser routines in the LUFA library. + * + * \return A value from the \ref JoystickHostWithParser_GetHIDReportDataCodes_t enum + */ +uint8_t GetHIDReportData(void) +{ + /* Create a buffer big enough to hold the entire returned HID report */ + uint8_t HIDReportData[HIDReportSize]; + + USB_ControlRequest = (USB_Request_Header_t) + { + .bmRequestType = (REQDIR_DEVICETOHOST | REQTYPE_STANDARD | REQREC_INTERFACE), + .bRequest = REQ_GetDescriptor, + .wValue = (HID_DTYPE_Report << 8), + .wIndex = 0, + .wLength = HIDReportSize, + }; + + /* Select the control pipe for the request transfer */ + Pipe_SelectPipe(PIPE_CONTROLPIPE); + + /* Send control request to retrieve the HID report from the attached device */ + if (USB_Host_SendControlRequest(HIDReportData) != HOST_SENDCONTROL_Successful) + return ParseControlError; + + /* Send the HID report to the parser for processing */ + if (USB_ProcessHIDReport(HIDReportData, HIDReportSize, &HIDReportInfo) != HID_PARSE_Successful) + return ParseError; + + return ParseSuccessful; +} + +/** Callback for the HID Report Parser. This function is called each time the HID report parser is about to store + * an IN, OUT or FEATURE item into the HIDReportInfo structure. To save on RAM, we are able to filter out items + * we aren't interested in (preventing us from being able to extract them later on, but saving on the RAM they would + * have occupied). + * + * \param[in] CurrentItem Pointer to the item the HID report parser is currently working with + * + * \return Boolean \c true if the item should be stored into the HID report structure, \c false if it should be discarded + */ +bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_t* const CurrentItem) +{ + bool IsJoystick = false; + + /* Iterate through the item's collection path, until either the root collection node or a collection with the + * Joystick Usage is found - this prevents Mice, which use identical descriptors except for the Mouse usage + * parent node, from being erroneously treated as a joystick + */ + for (HID_CollectionPath_t* CurrPath = CurrentItem->CollectionPath; CurrPath != NULL; CurrPath = CurrPath->Parent) + { + if ((CurrPath->Usage.Page == USAGE_PAGE_GENERIC_DCTRL) && + (CurrPath->Usage.Usage == USAGE_JOYSTICK)) + { + IsJoystick = true; + break; + } + } + + /* If a collection with the joystick usage was not found, indicate that we are not interested in this item */ + if (!IsJoystick) + return false; + + /* Check the attributes of the current joystick item - see if we are interested in it or not; + * only store BUTTON and GENERIC_DESKTOP_CONTROL items into the Processed HID Report + * structure to save RAM and ignore the rest + */ + return ((CurrentItem->Attributes.Usage.Page == USAGE_PAGE_BUTTON) || + (CurrentItem->Attributes.Usage.Page == USAGE_PAGE_GENERIC_DCTRL)); +} + |