On 09.08.21 09:58, Muni Sekhar wrote: > Hi all, > > PCIe memory mapped registers can be read via readb(), readw(), readl() > kernel API's. Similarly what are the kernel API to read the device > registers via USB bus > Hi, I am afraid this is based on a fundamental misunderstanding on how USB works. It is based on passing messages, not reading and writing registers. USB devices are primarily based on endpoints, not registers. A literal answer to your question would point you to the clear/set/get_feature standard requests of chapter 9 of the specification, but that really will not help you, as you are making assumption that fundamentally do not apply. I hope this list stays friendly to newcomers and we will answer specific questions, but at this point I must advise you to first read an introductory book. HTH Oliver
