1. 25 Aug, 2015 1 commit
    • Mark Rutland's avatar
      Docs: dt: add generic MSI bindings · 126b16e2
      Mark Rutland authored
      Currently msi-parent is used in a couple of drivers despite being fairly
      underspecified. This patch adds a generic binding for MSIs (including
      the existing msi-parent property) enabling the description of platform
      devices capable of using MSIs.
      
      While MSIs are primarily distinguished by doorbell and payload, some MSI
      controllers (e.g. the GICv3 ITS) also use side-band information
      accompanying the write to identify the master which originated the MSI,
      to allow for sandboxing. This sideband information is non-probeable and
      needs to be described in the DT. Other MSI controllers may have
      additional configuration details which need to be described per-master.
      
      This patch adds a generic msi-parent binding document, extending the
      de-facto standard with a new (optional) #msi-cells which can be used to
      express any per-master configuration and/or sideband data. This is
      sufficient to describe non-hotpluggable devices.
      
      For busses where sideband data may be derived from some bus-specific
      master ID scheme, other properties will be required to describe the
      mapping.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
      126b16e2