Should HID device have Data IN endpoint if it doesn't initiate any IN transfers?
Many people say it's required by standard. But in my opinion HID devices specification is unclear about whether they are obliged to have IN endpoint or not. I look here: http://www.usb.org/developers/hidpage/HID1_11.pdf.
Page 10 contains "Required" "Y", but it could mean "required to send unrequested data". Page 67 says the following about bNumEndpoints: "If this value is zero, this interface only uses endpoint zero". So, likely it's ok not to have endpoint IN. Windows doesn't require it neither (at least some versions).
Who feels to know a good answer?