[PATCH v6 0/6] clk: spacemit: add K1 reset support

Alex Elder
2025-05-06T21:06:44Z

This series adds reset controller support for the SpacemiT K1 SoC.

This code builds upon the clock controller driver from Haylen Chu.
This version has been reworked to use the auxiliary device model,
as requested by Stephen Boyd. As a result the reset code resides
under drivers/reset rather than drivers/clk. A new header file
holds definitions used by the clock and reset drivers. The first
patch is the same as before, so I preserved Krzysztof's Reviewed-by
tag. I dropped the tags from Haylen and Philipp, given the new
location of the code. (The actual reset code is largely the same.)

This series is based on the "for-next" branch in the SpacemiT
repository:
https://github.com/spacemit-com/linux/tree/for-next

All of these patches are available here:
https://github.com/riscstar/linux/tree/outgoing/reset-v6

Between version 5 and version 6:
- Reworked the code to use the auxiliary device framework.
- Moved the code supporting reset under drivers/reset/spacemit.
- Created a new header file shared by reset and clock.
- Separated generic from SoC-specific code in the reset driver.
- Dropped two Reviewed-by tags.

Between version 4 and version 5:
- Added Haylen's Reviewed-by on the second patch.
- Added Philipp's Reviewed-by on the third patch.
- In patch 4, added a const qualifier to some structures, and removed
parentheses surrounding integer constants, as suggested by Philipp
- Now based on the SpacemiT for-next branch

Here is version 4 of this series.
https://lore.kernel.org/lkml/20250414191715.2264758-1-elder@riscstar.com/

Between version 3 and version 4:
- Now based on Haylen Chu's v7 clock code, built on v6.15-rc2.
- Added Krzysztof's Reviewed-by on the first patch.

Here is version 3 of this series.
https://lore.kernel.org/lkml/20250409211741.1171584-1-elder@riscstar.com/

Between version 2 and version 3 there was no feedback, however:
- Haylen posted v6 of the clock series, and it included some changes
that affected the logic in this reset code.
- I was informed that defining CCU nodes without any clocks led to
warnings about "clocks" being a required property when running
"make dtbs_check". For that reason, I made clock properties
optional for reset-only CCU nodes.
- This code is now based on v6.15-rc1, which includes a few commits
that were listed as dependencies previously.

Here is version 2 of this series.
https://lore.kernel.org/lkml/20250328210233.1077035-1-elder@riscstar.com/

Between version 1 and version 2:
- Added Rob's Reviewed-by tag on the first patch
- Renamed the of_match_data data type (and one or two other symbols) to
use "spacemit" rather than "k1".
- Replaced the abbreviated "rst" or "RST" in names of newly-defined
sympols with "reset" or "RESET" respectively.
- Eliminated rcdev_to_controller(), which was only used once.
- Changed a function that unsafely did a read/modify/write of a register
to use regmap_update_bits() instead as suggested by Haylen.
- Eliminated a null check for a pointer known to be non-null.
- Reordered the assignment of reset controller device fields.
- Added a "sentinel" comment as requested by Yixun.
- Updated to be based on Linux v6.14 final.

Here is the first version of this series.
https://lore.kernel.org/lkml/20250321151831.623575-1-elder@riscstar.com/

-Alex

Alex Elder (6):
dt-bindings: soc: spacemit: define spacemit,k1-ccu resets
soc: spacemit: create a header for clock/reset registers
clk: spacemit: set up reset auxiliary devices
reset: spacemit: add support for SpacemiT CCU resets
reset: spacemit: define three more CCUs
riscv: dts: spacemit: add reset support for the K1 SoC

.../soc/spacemit/spacemit,k1-syscon.yaml | 29 ++-
arch/riscv/boot/dts/spacemit/k1.dtsi | 18 ++
drivers/clk/spacemit/ccu-k1.c | 220 ++++++++---------
drivers/reset/Kconfig | 1 +
drivers/reset/Makefile | 1 +
drivers/reset/spacemit/Kconfig | 12 +
drivers/reset/spacemit/Makefile | 7 +
drivers/reset/spacemit/core.c | 61 +++++
drivers/reset/spacemit/core.h | 39 +++
drivers/reset/spacemit/k1.c | 231 ++++++++++++++++++
.../dt-bindings/clock/spacemit,k1-syscon.h | 128 ++++++++++
include/soc/spacemit/ccu_k1.h | 155 ++++++++++++
12 files changed, 777 insertions(+), 125 deletions(-)
create mode 100644 drivers/reset/spacemit/Kconfig
create mode 100644 drivers/reset/spacemit/Makefile
create mode 100644 drivers/reset/spacemit/core.c
create mode 100644 drivers/reset/spacemit/core.h
create mode 100644 drivers/reset/spacemit/k1.c
create mode 100644 include/soc/spacemit/ccu_k1.h

base-commit: cb9c3aeae509b36afbdf46942a7a0a0dfc856ce7
--
2.45.2