[PATCH v3 00/14] Support CPU frequency scaling on QCS404

[Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>]

The following patchset enables CPU frequency scaling support on the
QCS404 (with dynamic voltage scaling).

Patch 8 "clk: qcom: hfpll: CLK_IGNORE_UNUSED" is a bit controversial;
in this platform, this PLL provides the clock signal to a CPU
core. But in others it might not.

We opted for the minimal ammount of changes without affecting the
default functionality: simply bypassing the COMMON_CLK_DISABLE_UNUSED
framework and letting the firwmare chose whether to enable or disable
the clock at boot. However maybe a DT property and marking the clock
as critical would be more appropriate for this PLL. we'd appreciate the
maintainer's input on this topic.

v2:
   - dts: ms8916: apcs mux/divider: new bindings
     (the driver can still support the old bindings)
     
   - qcs404.dtsi
     fix apcs-hfpll definition
     fix cpu_opp_table definition
     
   - GPLL0_AO_OUT operating frequency
     define new alpha_pll_fixed_ops to limit the operating frequency

v3:
  - qcom-apcs-ipc-mailbox
    replace goto to ease readability
    
  - apcs-msm8916.c
    rework patch to use of_clk_parent_fill

  - hfpll.c
    add relevant comments to the code

  - qcs404.dtsi
    add voltage scaling support

Jorge Ramirez-Ortiz (14):
  clk: qcom: gcc: limit GPLL0_AO_OUT operating frequency
  mbox: qcom: add APCS child device for QCS404
  mbox: qcom: replace integer with valid macro
  dt-bindings: mailbox: qcom: Add clock-name optional property
  clk: qcom: apcs-msm8916: get parent clock names from DT
  clk: qcom: hfpll: get parent clock names from DT
  clk: qcom: hfpll: register as clock provider
  clk: qcom: hfpll: CLK_IGNORE_UNUSED
  arm64: dts: qcom: msm8916: Add the clocks for the APCS mux/divider
  arm64: dts: qcom: qcs404: Add OPP table
  arm64: dts: qcom: qcs404: Add HFPLL node
  arm64: dts: qcom: qcs404: Add the clocks for APCS mux/divider
  arm64: dts: qcom: qcs404: Add DVFS support
  arm64: defconfig: Enable HFPLL

 .../mailbox/qcom,apcs-kpss-global.txt         | 24 +++++++++--
 arch/arm64/boot/dts/qcom/msm8916.dtsi         |  3 +-
 arch/arm64/boot/dts/qcom/qcs404.dtsi          | 42 +++++++++++++++++++
 arch/arm64/configs/defconfig                  |  1 +
 drivers/clk/qcom/apcs-msm8916.c               | 23 ++++++++--
 drivers/clk/qcom/clk-alpha-pll.c              |  8 ++++
 drivers/clk/qcom/clk-alpha-pll.h              |  1 +
 drivers/clk/qcom/gcc-qcs404.c                 |  2 +-
 drivers/clk/qcom/hfpll.c                      | 25 ++++++++++-
 drivers/mailbox/qcom-apcs-ipc-mailbox.c       | 18 ++++----
 10 files changed, 130 insertions(+), 17 deletions(-)

-- 
2.21.0