• Ohad Ben-Cohen's avatar
    remoteproc: maintain a generic child device for each rproc · b5ab5e24
    Ohad Ben-Cohen authored
    For each registered rproc, maintain a generic remoteproc device whose
    parent is the low level platform-specific device (commonly a pdev, but
    it may certainly be any other type of device too).
    
    With this in hand, the resulting device hierarchy might then look like:
    
    omap-rproc.0
     |
     - remoteproc0  <---- new !
        |
        - virtio0
        |
        - virtio1
           |
           - rpmsg0
           |
           - rpmsg1
           |
           - rpmsg2
    
    Where:
    - omap-rproc.0 is the low level device that's bound to the
      driver which invokes rproc_register()
    - remoteproc0 is the result of this patch, and will be added by the
      remoteproc framework when rproc_register() is invoked
    - virtio0 and virtio1 are vdevs that are registered by remoteproc
      when it realizes that they are supported by the firmware
      of the physical remote processor represented by omap-rproc.0
    - rpmsg0, rpmsg1 and rpmsg2 are rpmsg devices that represent rpmsg
      channels, and are registerd by the rpmsg bus when it gets notified
      about their existence
    
    Technically, this patch:
    - changes 'struct rproc' to contain this generic remoteproc.x device
    - creates a new "remoteproc" type, to which this new generic remoteproc.x
      device belong to.
    - adds a super simple enumeration method for the indices of the
      remoteproc.x devices
    - updates all dev_* messaging to use the generic remoteproc.x device
      instead of the low level platform-specific device
    - updates all dma_* allocations to use the parent of remoteproc.x (where
      the platform-specific memory pools, most commonly CMA, are to be found)
    
    Adding this generic device has several merits:
    - we can now add remoteproc runtime PM support simply by hooking onto the
      new "remoteproc" type
    - all remoteproc log messages will now carry a common name prefix
      instead of having a platform-specific one
    - having a device as part of the rproc struct makes it possible to simplify
      refcounting (see subsequent patch)
    
    Thanks to Stephen Boyd <sboyd@codeaurora.org> for suggesting and
    discussing these ideas in one of the remoteproc review threads and
    to Fernando Guzman Lugo <fernando.lugo@ti.com> for trying them out
    with the (upcoming) runtime PM support for remoteproc.
    
    Cc: Fernando Guzman Lugo <fernando.lugo@ti.com>
    Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
    Signed-off-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
    b5ab5e24
virtio_rpmsg_bus.c 29.7 KB