18c2ecf20Sopenharmony_ciWhat: /sys/bus/amba/devices/.../driver_override 28c2ecf20Sopenharmony_ciDate: September 2014 38c2ecf20Sopenharmony_ciContact: Antonios Motakis <a.motakis@virtualopensystems.com> 48c2ecf20Sopenharmony_ciDescription: 58c2ecf20Sopenharmony_ci This file allows the driver for a device to be specified which 68c2ecf20Sopenharmony_ci will override standard OF, ACPI, ID table, and name matching. 78c2ecf20Sopenharmony_ci When specified, only a driver with a name matching the value 88c2ecf20Sopenharmony_ci written to driver_override will have an opportunity to bind to 98c2ecf20Sopenharmony_ci the device. The override is specified by writing a string to the 108c2ecf20Sopenharmony_ci driver_override file (echo vfio-amba > driver_override) and may 118c2ecf20Sopenharmony_ci be cleared with an empty string (echo > driver_override). 128c2ecf20Sopenharmony_ci This returns the device to standard matching rules binding. 138c2ecf20Sopenharmony_ci Writing to driver_override does not automatically unbind the 148c2ecf20Sopenharmony_ci device from its current driver or make any attempt to 158c2ecf20Sopenharmony_ci automatically load the specified driver. If no driver with a 168c2ecf20Sopenharmony_ci matching name is currently loaded in the kernel, the device will 178c2ecf20Sopenharmony_ci not bind to any driver. This also allows devices to opt-out of 188c2ecf20Sopenharmony_ci driver binding using a driver_override name such as "none". 198c2ecf20Sopenharmony_ci Only a single driver may be specified in the override, there is 208c2ecf20Sopenharmony_ci no support for parsing delimiters. 21