[v2,0/5] clk: samsung: Introduce Exynos850 SoC clock driver

Message

Sam Protsenko Oct. 7, 2021, 7:41 p.m. UTC

This patch series provides the implementation for Exynos850 clock
driver, its documentation and corresponding changes for Samsung clock
infrastructure (adds new PLL types used in Exynos850 SoC, following
TRM).

I tried to follow already established design for Samsung clock drivers
(getting most insights from Exynos5433 clock driver), and integrate the
driver into existing infrastructure. The whole driver was implemented
from scratch, using mostly TRM and downstream kernel for clock
dependencies/hierarchy info.

For now only basic clocks are implemented, including next blocks:
  - CMU_TOP
  - CMU_PERI
  - CMU_CORE
  - CMU_HSI
  - CMU_DPU

Some CMUs are still not implemented, but that can be added in future,
when the need arises. The driver also lacks CLKOUT support, PM ops and
automatic clocks control (using Q-Channel protocol). All that can be
added independently later.

Implemented clock tree was tested via UART and MMC drivers, and using
DebugFS clk support (e.g. using 'clk_summary' file). In order to keep
all clocks running I added 'clk_ignore_unused' kernel param in my local
tree, and defined CLOCK_ALLOW_WRITE_DEBUGFS in clk.c for actually
testing the clocks via DebugFS.

Changes in v2:
  - Added CMU_DPU implementation
  - Moved bus clock enablement to clk-exynos850.c
  - See also "v2 changes" list in each particular patch

Sam Protsenko (5):
  clk: samsung: clk-pll: Implement pll0822x PLL type
  clk: samsung: clk-pll: Implement pll0831x PLL type
  dt-bindings: clock: Add bindings definitions for Exynos850 CMU
  dt-bindings: clock: Document Exynos850 CMU bindings
  clk: samsung: Introduce Exynos850 clock driver

 .../clock/samsung,exynos850-clock.yaml        | 185 ++++
 drivers/clk/samsung/Makefile                  |   1 +
 drivers/clk/samsung/clk-exynos850.c           | 835 ++++++++++++++++++
 drivers/clk/samsung/clk-pll.c                 | 196 ++++
 drivers/clk/samsung/clk-pll.h                 |   2 +
 include/dt-bindings/clock/exynos850.h         | 141 +++
 6 files changed, 1360 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
 create mode 100644 drivers/clk/samsung/clk-exynos850.c
 create mode 100644 include/dt-bindings/clock/exynos850.h