Method and architecture for simplified communications with HID devices

A method of reading HID data items comprising the following steps:

• obtaining an HID report descriptor describing associated HID reports and 1, the arrangement, formatting, and usage specifications of data items within such HID reports;
• submitting the HID report descriptor to a parser through an interface;
• the parser performing a step of parsing the HID report descriptor and returning a parsed report description based on the HID report descriptor;
• obtaining an HID report containing data items described by the HID report descriptor;
• calling a first interface function with arguments comprising the HID report, the parsed report description, and a usage specification;
• and
• the first interface function finding and returning one or more data items from the HID report that have the same usage specifications as that specified in the arguments to the first interface function.

A computer-readable storage medium comprising computer-executable instructions that define a set of interface functions that are callable in a computer system having an HID device that provides HID reports containing data items and an HID report descriptor describing the HID reports and the arrangement, formatting, and usage specifications of data items within the HID reports;

• the set of interface functions defined by the instructions comprising:
• a descriptor parsing function that receives a function argument comprising an HID report descriptor, and in response parses the HID report descriptor and returns a parsed report description based on the HID report descriptor;
• and
• one or more item retrieval functions that receive function arguments comprising an HID report, the parsed report description, and a usage specification;
• said one or more item retrieval functions finding and returning one or more data items from the HID report that have the same usage specifications as that supplied in the arguments to the item retrieval functions.

In an HID class driver that receives HID reports of different sizes from one or more HID devices, a method of returning HID reports to requesting client programs, comprising the following steps:

• receiving HID reports from an HID device;
• normalizing the HID reports from the HID device by making them a uniform size;
• and
• returning the normalized HID reports to requesting client programs.

A computer system comprising:

• an HID driver that provides HID reports of different sizes from one or more HID devices;
• an HID class driver configured to request and receive the HID reports from the HID driver and to return the HID reports in response to requests from client programs;
• and
• wherein the HID class driver normalizes HID reports from a particular HID device by making them a uniform size.

A computer-readable storage medium comprising instructions that implement an HID class driver, the instructions being executable by a computer to perform the following steps:

• receiving HID reports from one or more HID devices;
• adding a report ID to any HID report that doesn't already have a report ID;
• normalizing HID reports from a particular HID device by making them a uniform size;
• and
• returning the normalized HID reports to requesting client programs.