On Wed, Dec 21, 2022 at 07:12:49AM +0100, Greg KH wrote: > On Tue, Dec 20, 2022 at 09:17:47PM +0530, Manjunatha Venkatesh wrote: > > Ultra-wideband (UWB) is a short-range wireless communication protocol. > > > > NXP has SR1XX family of UWB Subsystems (UWBS) devices. SR1XX SOCs > > are FiRa Compliant. SR1XX SOCs are flash less devices and they need > > Firmware Download on every device boot. More details on the SR1XX Family > > can be found at https://www.nxp.com/products/:UWB-TRIMENSION > > > > The sr1xx driver work the SR1XX Family of UWBS, and uses UWB Controller > > Interface (UCI). The corresponding details are available in the FiRa > > Consortium Website (https://www.firaconsortium.org/). > > > > Internally driver will handle two modes of operation. > > 1.HBCI mode (sr1xx BootROM Code Interface) > > Firmware download uses HBCI ptotocol packet structure which is > > Nxp proprietary,Firmware File(.bin) stored in user space context > > and during device init sequence pick the firmware packet in chunk > > and send it to the driver with write() api call. > > > > After the firmware download sequence at the end UWBS will > > send device status notification and its indication of device entered > > UCI mode. > > Here after any command/response/notification will follow > > UCI packet structure. > > > > 2.UCI mode (UWB Command interface) > > Once Firmware download finishes sr1xx will switch to UCI mode. > > Then driver exchange command/response/notification as per the FIRA UCI > > standard format between user space and sr1xx device. > > Any response or notification received from sr1xx through SPI line > > will convey to user space. > > > > Its Interrupt based driver and IO Handshake needed with SR1XX Family of > > SOCs. > > This driver needs dts config update as per the sr1xx data sheet. > > Corresponding document available in Documentation/devicetree/bindings/uwb > > [ ... ] > > Also, I see no justification here for why this has to be a kernel > driver, OR where the userspace code is that controls this. > After seeing all the warnings generated by 0-day after this driver was applied to chromeos-6.1, my basic question is similar but boils down to: Why does this need a userspace component to start with, and why wasn't it implemented as firmware download driver ? Guenter
