1. 27 Jan, 2016 2 commits
    • Mark Brown's avatar
      MIPS: dt: Explicitly specify native endian behaviour for syscon · 25d6463e
      Mark Brown authored
      On many MIPS systems the endianness of IP blocks is kept the same as
      that of the CPU by the hardware.  This includes the system controllers
      on these systems which are controlled via syscon which uses the regmap
      API which used readl() and writel() to interact with the hardware,
      meaning that all writes are converted to little endian when writing to
      the hardware.  This caused a bad interaction with the regmap core in big
      endian mode since it was not aware of the byte swapping and so ended up
      performing little endian writes.
      
      Unfortunately when this issue was noticed it was addressed by updating
      the DT for the affected devices to specify them as little endian.  This
      happened to work since it resulted in two endianness swaps which
      cancelled each other out and gave little endian behaviour but meant that
      the DT was clearly not accurately describing the hardware.
      
      The intention of commit 29bb45f2 (regmap-mmio: Use native
      endianness for read/write) was to fix this by making regmap default to
      native endianness but this breaks most other MMIO users where the
      hardware has a fixed endianness and the implementation uses the __raw
      accessors which are not intended to be used outside of architecture
      code.  Instead use the newly added native-endian DT property to say
      exactly what we want for these systems.
      
      Fixes: 29bb45f2 (regmap-mmio: Use native endianness for read/write)
      Reported-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
      25d6463e
    • Mark Brown's avatar
      regmap: Add explict native endian flag to DT bindings · a06c488d
      Mark Brown authored
      Currently the binding document says that if no endianness is configured
      we use native endian but this is not in fact true for all binding types
      and we do have some devices that really want native endianness such as
      Broadcom MIPS SoCs where switching the endianness of the CPU also
      switches the endianness of external IPs.
      
      Provide an explicit option for this.
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      a06c488d
  2. 24 Jan, 2016 38 commits