• Pawel Moll's avatar
    mfd: vexpress: Convert custom func API to regmap · 3b9334ac
    Pawel Moll authored
    Components of the Versatile Express platform (configuration
    microcontrollers on motherboard and daughterboards in particular)
    talk to each other over a custom configuration bus. They
    provide miscellaneous functions (from clock generator control
    to energy sensors) which are represented as platform devices
    (and Device Tree nodes). The transactions on the bus can
    be generated by different "bridges" in the system, some
    of which are universal for the whole platform (for the price
    of high transfer latencies), others restricted to a subsystem
    (but much faster).
    
    Until now drivers for such functions were using custom "func"
    API, which is being replaced in this patch by regmap calls.
    This required:
    
    * a rework (and move to drivers/bus directory, as suggested
      by Samuel and Arnd) of the config bus core, which is much
      simpler now and uses device model infrastructure (class)
      to keep track of the bridges; non-DT case (soon to be
      retired anyway) is simply covered by a special device
      registration function
    
    * the new config-bus driver also takes over device population,
      so there is no need for special matching table for
      of_platform_populate nor "simple-bus" hack in the arm64
      model dtsi file (relevant bindings documentation has
      been updated); this allows all the vexpress devices
      fit into normal device model, making it possible
      to remove plenty of early inits and other hacks in
      the near future
    
    * adaptation of the syscfg bridge implementation in the
      sysreg driver, again making it much simpler; there is
      a special case of the "energy" function spanning two
      registers, where they should be both defined in the tree
      now, but backward compatibility is maintained in the code
    
    * modification of the relevant drivers:
    
      * hwmon - just a straight-forward API change
      * power/reset driver - API change
      * regulator - API change plus error handling
        simplification
      * osc clock driver - this one required larger rework
        in order to turn in into a standard platform driver
    Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
    Acked-by: default avatarMark Brown <broonie@linaro.org>
    Acked-by: default avatarLee Jones <lee.jones@linaro.org>
    Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Acked-by: default avatarMike Turquette <mturquette@linaro.org>
    3b9334ac
vexpress.txt 6.94 KB