[v6,0/5] PCI: qcom: Rework pipe_clk/pipe_clk_src handling

PCIe pipe clk (and some other clocks) must be parked to the "safe"
source (bi_tcxo) when corresponding GDSC is turned off and on again.
Currently this is handcoded in the PCIe driver by reparenting the
gcc_pipe_N_clk_src clock.

Instead of doing it manually, follow the approach used by
clk_rcg2_shared_ops and implement this parking in the enable() and
disable() clock operations for respective pipe clocks.

Changes since v5:
 - Rename the clock to clk-regmap-phy-mux and the enable/disable values
   to phy_src_val and ref_src_val respectively (as recommended by
   Johan).

Changes since v4:
 - Renamed the clock to clk-regmap-pipe-src,
 - Added mention of PCIe2 PHY to the commit message,
 - Expanded commit messages to mention additional pipe clock details.

Changes since v3:
 - Replaced the clock multiplexer implementation with branch-like clock.

Changes since v2:
 - Added is_enabled() callback
 - Added default parent to the pipe clock configuration

Changes since v1:
 - Rebased on top of [1].
 - Removed erroneous Fixes tag from the patch 4.

Changes since RFC:
 - Rework clk-regmap-mux fields. Specify safe parent as P_* value rather
   than specifying the register value directly
 - Expand commit message to the first patch to specially mention that
   it is required only on newer generations of Qualcomm chipsets.


Dmitry Baryshkov (5):
  PCI: qcom: Remove unnecessary pipe_clk handling
  clk: qcom: regmap: add PHY clock source implementation
  clk: qcom: gcc-sm8450: use new clk_regmap_pipe_src_ops for PCIe pipe
    clocks
  clk: qcom: gcc-sc7280: use new clk_regmap_pipe_src_ops for PCIe pipe
    clocks
  PCI: qcom: Drop manual pipe_clk_src handling

 drivers/clk/qcom/Makefile              |  1 +
 drivers/clk/qcom/clk-regmap-phy-mux.c  | 62 ++++++++++++++++++++
 drivers/clk/qcom/clk-regmap-phy-mux.h  | 37 ++++++++++++
 drivers/clk/qcom/gcc-sc7280.c          | 49 ++++++----------
 drivers/clk/qcom/gcc-sm8450.c          | 51 ++++++----------
 drivers/pci/controller/dwc/pcie-qcom.c | 81 +-------------------------
 6 files changed, 141 insertions(+), 140 deletions(-)
 create mode 100644 drivers/clk/qcom/clk-regmap-phy-mux.c
 create mode 100644 drivers/clk/qcom/clk-regmap-phy-mux.h


base-commit: 3123109284176b1532874591f7c81f3837bbdc17
prerequisite-patch-id: 71e4b5b7ff5d87f2407735cc6a3074812cde3697

On Fri, May 13, 2022 at 08:53:34PM +0300, Dmitry Baryshkov wrote:
> PCIe pipe clk (and some other clocks) must be parked to the "safe"
> source (bi_tcxo) when corresponding GDSC is turned off and on again.
> Currently this is handcoded in the PCIe driver by reparenting the
> gcc_pipe_N_clk_src clock.
> 
> Instead of doing it manually, follow the approach used by
> clk_rcg2_shared_ops and implement this parking in the enable() and
> disable() clock operations for respective pipe clocks.
> 
> Changes since v5:
>  - Rename the clock to clk-regmap-phy-mux and the enable/disable values
>    to phy_src_val and ref_src_val respectively (as recommended by
>    Johan).
> 
> Changes since v4:
>  - Renamed the clock to clk-regmap-pipe-src,
>  - Added mention of PCIe2 PHY to the commit message,
>  - Expanded commit messages to mention additional pipe clock details.
> 
> Changes since v3:
>  - Replaced the clock multiplexer implementation with branch-like clock.
> 
> Changes since v2:
>  - Added is_enabled() callback
>  - Added default parent to the pipe clock configuration
> 
> Changes since v1:
>  - Rebased on top of [1].
>  - Removed erroneous Fixes tag from the patch 4.
> 
> Changes since RFC:
>  - Rework clk-regmap-mux fields. Specify safe parent as P_* value rather
>    than specifying the register value directly
>  - Expand commit message to the first patch to specially mention that
>    it is required only on newer generations of Qualcomm chipsets.
> 
> 
> Dmitry Baryshkov (5):
>   PCI: qcom: Remove unnecessary pipe_clk handling
>   clk: qcom: regmap: add PHY clock source implementation
>   clk: qcom: gcc-sm8450: use new clk_regmap_pipe_src_ops for PCIe pipe
>     clocks
>   clk: qcom: gcc-sc7280: use new clk_regmap_pipe_src_ops for PCIe pipe
>     clocks
>   PCI: qcom: Drop manual pipe_clk_src handling

So Bjorn A has already applied v2 of the three clock patches this series
to his tree. I guess dropping or reverting does is the best way to
handle this since trying to fix things up incrementally would just be
messy.

Johan