Re: [PATCH 2/3] mfd: vexpress: Convert custom func API to regmap

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Feb 11, 2014 at 04:53:29PM +0000, Pawel Moll wrote:
> 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
>   * regulator - API change plus error handling
>     simplification
>   * power/reset driver - API change, but as devm_regmap*()
>     can't be called when the system is dying, it must
>     be requested at driver probe time
>   * osc clock driver - this one required larger rework
>     in order to turn in into a standard platform driver
>     (and this a good thing on its own)
> 
> Signed-off-by: Pawel Moll <pawel.moll@arm.com>
> ---
>  .../devicetree/bindings/arm/vexpress-sysreg.txt    |  43 ++-
>  Documentation/devicetree/bindings/arm/vexpress.txt |  15 +-
>  arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts         |   5 +-
>  arch/arm/mach-vexpress/ct-ca9x4.c                  |  10 +-
>  arch/arm/mach-vexpress/v2m.c                       |  18 +-
>  arch/arm64/boot/dts/rtsm_ve-motherboard.dtsi       |   2 +-
>  drivers/bus/Kconfig                                |   9 +
>  drivers/bus/Makefile                               |   2 +
>  drivers/bus/vexpress-config.c                      | 202 +++++++++++
>  drivers/clk/versatile/clk-vexpress-osc.c           |  94 +++--
>  drivers/hwmon/vexpress.c                           |  15 +-
>  drivers/mfd/Kconfig                                |   7 -
>  drivers/mfd/Makefile                               |   2 +-
>  drivers/mfd/vexpress-config.c                      | 288 ---------------
>  drivers/mfd/vexpress-sysreg.c                      | 395 +++++++++++----------
>  drivers/power/reset/vexpress-poweroff.c            |  13 +-
>  drivers/regulator/vexpress.c                       |  50 +--
>  include/linux/vexpress.h                           |  79 +----
>  18 files changed, 568 insertions(+), 681 deletions(-)
>  create mode 100644 drivers/bus/vexpress-config.c
>  delete mode 100644 drivers/mfd/vexpress-config.c
> 

For hwmon:

Acked-by: Guenter Roeck <linux@roeck-us.net>