This is something I've been meaning to do for a while but only just got around to. The CCF has been quite unwieldy in a few ways:
* It is very rigid, and there are not easy ways to hook into it without rewriting many things. See e.g. things like the bypass clock and all the _half clocks which were created because CCF didn't support the dividers used on the k210. While preparing this series, I encountered several edge cases which I had initially overlooked (or which were not supported in the initial release). These would have been very difficult to fix with CCF, but were much easier to address be * There is a lot of magic going on under the curtains because of all the CCF code which lives in many different files. Some things live in drivers, but many things live in e.g. clk-uclass.c. So many things live in so many files and it can be very difficult to get a handle on what exactly happens. Complicating this is that there is a conflation of struct clk as a handle and struct clk as a device. In this regard, refcounting is completely broken. IMO we should just do away with refcounts and only disable clocks when explicitly asked for. * It is very dependent on runtime initialization. Typically, everything is initialized by calling into various register() functions, usually with several wrappers to avoid specifying all the arguments. This balloons the runtime memory usage since there are so many devices created. It also makes it hard to debug, since if you do it the "typical" way it is easy to accidentally assign a clock to the wrong register. * It inflates code size by pulling in not just some dead code (e.g. this driver does not use divider tables but they are in clk-divider anyway) but also pulling in numerous imx-specific clocks. This could be fixed, but I don't want to due to the other reasons listed.
I am very happy to have completely excised it from my driver. IMO there should be big warning signs on the CCF warning not to use it for new code. This would hopefully dissuade those like myself who had no idea that CCF was *not* in fact a good way to write a clock driver.
Overall there is a total savings of 12k from this series. Before: text data bss dec hex filename 292485 32672 12624 337781 52775 u-boot After: text data bss dec hex filename 283125 29856 12624 325605 4f7e5 u-boot
This series depends on https://patchwork.ozlabs.org/project/uboot/list/?series=238211
Sean Anderson (11): clk: Allow force setting clock defaults before relocation clk: k210: Rewrite to remove CCF clk: k210: Move pll into the rest of the driver clk: k210: Implement soc_clk_dump clk: k210: Re-add support for setting rate clk: k210: Don't set PLL rates if we are already at the correct rate clk: k210: Remove bypass driver clk: k210: Move k210 clock out of its own subdirectory k210: dts: Set PLL1 to the same rate as PLL0 k210: Don't imply CCF test: Add K210 PLL tests to sandbox defconfigs
MAINTAINERS | 4 +- arch/riscv/dts/k210.dtsi | 2 + board/sipeed/maix/Kconfig | 2 - configs/sandbox64_defconfig | 2 + configs/sandbox_defconfig | 2 + configs/sandbox_flattree_defconfig | 2 + configs/sipeed_maix_bitm_defconfig | 1 - drivers/clk/Kconfig | 14 +- drivers/clk/Makefile | 2 +- drivers/clk/clk-uclass.c | 9 +- drivers/clk/clk_kendryte.c | 1319 +++++++++++++++++++++++ drivers/clk/kendryte/Kconfig | 12 - drivers/clk/kendryte/Makefile | 1 - drivers/clk/kendryte/bypass.c | 273 ----- drivers/clk/kendryte/clk.c | 668 ------------ drivers/clk/kendryte/pll.c | 585 ---------- include/clk.h | 4 +- include/dt-bindings/clock/k210-sysctl.h | 94 +- include/kendryte/bypass.h | 31 - include/kendryte/clk.h | 35 - include/kendryte/pll.h | 34 - 21 files changed, 1399 insertions(+), 1697 deletions(-) create mode 100644 drivers/clk/clk_kendryte.c delete mode 100644 drivers/clk/kendryte/Kconfig delete mode 100644 drivers/clk/kendryte/Makefile delete mode 100644 drivers/clk/kendryte/bypass.c delete mode 100644 drivers/clk/kendryte/clk.c delete mode 100644 drivers/clk/kendryte/pll.c delete mode 100644 include/kendryte/bypass.h delete mode 100644 include/kendryte/clk.h