Am Donnerstag, den 05.04.2018, 08:26 +0200 schrieb Greg KH: > > The USB device can describe itself properly. The SMBIOS function is a > > requirement from our customer who designed a board using our device where > > their CPU reads from a specific BIOS location and initializes GPIOs based > > on the settings. These GPIOs set the mode of the transceiver (LOOPBACK, > > RS232, RS485, or RS422). Therefore, the driver also reads the same > > settings from the BIOS, so that it can enable the appropriate mode. > > That logic can be done in userspace, no need to do that within the > kernel, right?
No, not if you want to do full RS485 and similar stuff. Yet ACM is not a full serial interface. It is for modems. That raises two questions a) why not add this to cdc-acm? b) why custom ioctls? The kernel can do those serial protocols at upper levels. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html