On 9/29/22 09:38, Krzysztof Kozlowski wrote:
On 29/09/2022 16:20, Dinh Nguyen wrote:
So this change will not be backwards compatible with existing DTBs. I
noticed that patch2 updates the DTS files for the arm64 platforms, but
there seems to be some arm32 platforms too. Isn't this going to be a
problem?
The arm32 platforms makes the clk-phase adjustment through the clock
driver. There was a discussion when I originally submitted the support
for the arm32 platforms, and we landed on going through the clock driver
instead of using the MMC driver. The updates to the arm32 platforms can
be done after this patch series.
How the update "can be done after"? Didn't you break all boards in- and
out-of-tree?
I don't think so! At least, I don't see how, for the arm32 boards, here
are the dts entry for setting the clock-phase:
sdmmc_clk: sdmmc_clk {
#clock-cells = <0>;
compatible = "altr,socfpga-gate-clk";
clocks = <&f2s_periph_ref_clk>, <&main_nand_sdmmc_clk>,<&per_nand_mmc_clk>;
clk-gate = <0xa0 8>;
clk-phase = <0 135>; <-----
};
sdmmc_clk_divided: sdmmc_clk_divided {
#clock-cells = <0>;
compatible = "altr,socfpga-gate-clk";
clocks = <&sdmmc_clk>;
clk-gate = <0xa0 8>;
fixed-divider = <4>;
};
...
mmc: dwmmc0@ff704000 {
compatible = "altr,socfpga-dw-mshc";
reg = <0xff704000 0x1000>;
interrupts = <0 139 4>;
fifo-depth = <0x400>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&l4_mp_clk>, <&sdmmc_clk_divided>;
clock-names = "biu", "ciu";
resets = <&rst SDMMC_RESET>;
status = "disabled";
};
So the setting for the clk-phase is done in the clock driver,
(drivers/clk/socfpga/clk-gate.c). This has been done many years now,
before the clk-phase-hs-sd concept was added to the sdmmc driver.
When I originally submitted the patches for the ARM64 clock driver
support, I forgot to add the clk-phase support for the SD controller.
Now that I realized we needed it, the concept to set the clk-phase is in
the SD driver, thus I'm just adding the support for arm64.
The arm32 support does not change in any way, so I don't see how it will
break it.
I can update the arm32 support with the same function in patch3 after
this series. Because updating the arm32 will require me to remove the
support in the clock driver, thus, I want to break it out.
Dinh
