[PATCH v4 00/24] drm/msm/dsi: refactor MSM DSI PHY/PLL drivers

[Dmitry Baryshkov]

Restructure MSM DSI PHY drivers. What started as an attempt to grok the
overcomplicated PHY drivers, has lead up to the idea of merging PHY and
PLL code, reducing abstractions, code duplication, dropping dead code,
etc.

The patches were mainly tested on RB5 (sm8250, 7nm) and DB410c (apq8016,
28nm-lp) and lightly tested on RB3 (sdm845, 10nm).

This patchet depends on the patch "clk: fixed: add devm helper for
clk_hw_register_fixed_factor()", which was merged in 5.12-rc1:
https://lore.kernel.org/r/20210211052206.2955988-4-daniel@0x0f.com


Changes since v3:
 - Rename save_state/restore_state functions/callbacks
 - Still mention DSI_1 when determining settings for slave PHYs in 14nm
   and 28nm drivers.
 - Stop including the external dependency merged upstream long ago. It
   is properly mentioned in the patchset description.

Changes since v2:
 - Drop the 'stop setting clock parents manually' patch for now together
   with the dtsi changes. Unlike the rest of patchset it provides
   functional changes and might require additional discussion.
   The patchset will be resubmitted later.

Changes since v1:
 - Rebase on top of msm/msm-next
 - Reorder patches to follow logical sequence
 - Add sc7180 clocks assignment
 - Drop sm8250 clocks assignment, as respective file is not updated in
   msm/msm-next

Changes since RFC:
 - Reorder patches to move global clock patches in the beginning and
   dtsi patches where they are required.
 - remove msm_dsi_phy_set_src_pll() and guess src_pll_id using PHY usecase.