[PATCH v3 0/7] clk: thead: Add support for TH1520 AP_SUBSYS clock controller

[Drew Fustini]

This series adds support for the AP sub-system clock controller in the
T-Head TH1520 [1]. Yangtao Li originally submitted this series in May
2023 [2]. Jisheng made additional improvements and then passed on the
work in progress to me.

Link: https://openbeagle.org/beaglev-ahead/beaglev-ahead/-/blob/main/docs/TH1520%20System%20User%20Manual.pdf [1]
Link: https://lore.kernel.org/all/20230515054402.27633-1-frank.li@vivo.com/ [2]

Changes in v3:
 - dt-binding patch has been applied to clk-next by Stephen but I'm
   keeping it in the series for completeness.
 - move dt-bindings include after linux includes in driver
 - change rate to u64 in th1520_pll_vco_recalc_rate()
 - replace do_div() with normal division operation in both
   th1520_pll_vco_recalc_rate() and th1520_pll_postdiv_recalc_rate()
 - add static to ccu_mux structs: c910_i0_clk, c910_clk, uart_sclk

Changes in v2: 
 - Add clock property to the gpio nodes after Conor asked why they were
   missing. These clock gates correspond to enable bits in PERI_CLK_CFG.
 - Drop 2 cell address and size properties from the binding example per
   Conor and add Reviewed-by from from Conor.
 - Link: https://lore.kernel.org/linux-riscv/20240623-th1520-clk-v2-0-ad8d6432d9fb@tenstorrent.com/ 

Changes in v1:
 - Split th1520_clks into groups for gate, mux, div, pll
 - Convert gate clocks to devm_clk_hw_register_gate_parent_data()
 - Convert mux clocks to devm_clk_hw_register_mux_parent_data_table()
 - Split the PLL recalculation into th1520_pll_vco_recalc_rate() and
   th1520_pll_postdiv_recalc_rate(). Based on Emil's comments in v1,
   add logic to handle the fractional portion of feedback divide value
   when the delta-sigma modulator (DSM) is active.
 - Drop clock-names from the binding per Stephan to avoid relying on
   anything other than the cell index when describing clk_parent_data
   (note: I dropped Rob's Rb because I changed the binding patch)
 - Rename reg/reg2 to cfg0/cfg1 to match the SoC documentation
 - Rename struct for pll clocks from ccu_mdiv to ccu_pll
 - Rebase on v6.10-rc3, remove the dts node reordering patch from v3
   now that it is in mainline
 - Link: https://lore.kernel.org/linux-riscv/20240615-th1520-clk-v1-0-3ba4978c4d6b@tenstorrent.com/

Changes in RFC v3:
 - Drop redundant new line and unused clk label from the dts example in
   the DT binding which I failed to fix in v2.
 - Add patch [4] from Thomas Bonnefille that fixes dts node ordering in
   th1520.dtsi. Conor has already merged it into riscv-dt-for-next so
   the dts patches in this series are based on top of that.
 - Remove fixed uart clock and converted uart DT nodes to use clocks
   from the clock controller.
 - Remove fixed apb clock and converted the dma controller and timer DT
   nodes to use a clock from the clock controller.
 - Made ccu_disable_helper() and ccu_enable_helper() to static functions
 - Follow the advice from Stephen Boyd in Yangtao's original series to
   not use strings for clk tree topology. Created clk_parent_data arrays
   to be used with CLK_HW_INIT_PARENTS_DATA instead of parent strings.
 - Rebase on top of v6.9-rc7
 - Link: https://lore.kernel.org/all/20240506-th1520-clk-v3-0-085a18a23a7f@tenstorrent.com/

Changes in RFC v2:
 - squash the header file patch into the DT schema patch
 - describe the changes I made to original series in the cover letter
   instead of the individual patches
 - fix my typo in my email address
 - Link: https://lore.kernel.org/all/20240426-th1520-clk-v2-v2-0-96b829e6fcee@tenstorrent.com/

Changes in RFC v1 compared to the original series:
 - corrected the npu_clk enable bit
 - deduplicated CLK_NPU and CLK_NPU_AXI number in header
 - fixed c910_i0_clk reg typo
 - fixed checkpatch and dt_binding_check warnings
 - rebased on v6.9-rc5
 - revised commit descriptions
 - Link: https://lore.kernel.org/all/20240110-clk-th1520-v1-0-8b0682567984@tenstorrent.com/

Thank you,
Drew

---
Drew Fustini (7):
      dt-bindings: clock: Document T-Head TH1520 AP_SUBSYS controller
      clk: thead: Add support for T-Head TH1520 AP_SUBSYS clocks
      riscv: dts: thead: Add TH1520 AP_SUBSYS clock controller
      riscv: dts: thead: change TH1520 uart nodes to use clock controller
      riscv: dts: thead: change TH1520 mmc nodes to use clock controller
      riscv: dts: thead: update TH1520 dma and timer nodes to use clock controller
      riscv: dts: thead: add clock to TH1520 gpio nodes

 .../bindings/clock/thead,th1520-clk-ap.yaml        |   53 +
 MAINTAINERS                                        |    3 +
 arch/riscv/boot/dts/thead/th1520-beaglev-ahead.dts |   12 -
 .../boot/dts/thead/th1520-lichee-module-4a.dtsi    |   12 -
 arch/riscv/boot/dts/thead/th1520.dtsi              |   73 +-
 drivers/clk/Kconfig                                |    1 +
 drivers/clk/Makefile                               |    1 +
 drivers/clk/thead/Kconfig                          |   12 +
 drivers/clk/thead/Makefile                         |    2 +
 drivers/clk/thead/clk-th1520-ap.c                  | 1089 ++++++++++++++++++++
 include/dt-bindings/clock/thead,th1520-clk-ap.h    |   96 ++
 11 files changed, 1293 insertions(+), 61 deletions(-)
---
base-commit: 256abd8e550ce977b728be79a74e1729438b4948
change-id: 20240710-th1520-clk-0ad976e2a42e

Best regards,
-- 
Drew Fustini <dfustini at tenstorrent.com>