On Fri, Apr 26, 2024 at 04:12:00PM +0200, Thomas Bonnefille wrote: > > > On 4/25/24 6:35 PM, Conor Dooley wrote: > > On Thu, Apr 25, 2024 at 09:51:26AM -0500, Rob Herring wrote: > > > > > > On Thu, 25 Apr 2024 10:21:31 +0200, Thomas Bonnefille wrote: > > > > This adds I2C support in the device tree of the T-Head TH1520 RISCV-SoC > > > > and a default configuration for the BeagleV-Ahead. It appears that the > > > > TH1520 I2C is already supported in the upstream kernel through the > > > > Synopsis Designware I2C adapter driver. > > > > As there is no clock driver for this board as of today, this patch > > > > series uses a fixed-clock named i2c_ic_clk. > > > > There is also no pinctrl driver yet so pinmux must be handled manually > > > > for now. > > > > It also fixes the order of the nodes in the device tree to comply with > > > > device-tree coding-style. > > > > > > > > Thomas Bonnefille (4): > > > > dt-bindings: i2c: dw: Document compatible thead,th1520-i2c > > > > riscv: boot: dts: thead: Fix node ordering in TH1520 device tree > > > > riscv: dts: thead: Add TH1520 I2C nodes > > > > riscv: dts: thead: Enable I2C on the BeagleV-Ahead > > > > > > > > .../bindings/i2c/snps,designware-i2c.yaml | 12 ++ > > > > .../boot/dts/thead/th1520-beaglev-ahead.dts | 22 ++++ > > > > arch/riscv/boot/dts/thead/th1520.dtsi | 120 ++++++++++++++---- > > > > 3 files changed, 127 insertions(+), 27 deletions(-) > > > > > > > > -- > > > > 2.44.0 > > > > > > > > > > > > > > > > > > > > > My bot found new DTB warnings on the .dts files added or changed in this > > > series. > > > > > > Some warnings may be from an existing SoC .dtsi. Or perhaps the warnings > > > are fixed by another series. Ultimately, it is up to the platform > > > maintainer whether these warnings are acceptable or not. No need to reply > > > unless the platform maintainer has comments. > > > > > > If you already ran DT checks and didn't see these error(s), then > > > make sure dt-schema is up to date: > > > > > > pip3 install dtschema --upgrade > > > > > > > > > New warnings running 'make CHECK_DTBS=y thead/th1520-beaglev-ahead.dtb' for 20240425082138.374445-1-thomas.bonnefille@xxxxxxxxxxx: > > > > > > arch/riscv/boot/dts/thead/th1520-beaglev-ahead.dtb: i2c-clock: clock-frequency:0:0: 50000000 is greater than the maximum of 5000000 > > > > The bot is not freaking out here, 50 MHz is indeed more than 5 MHz :) > > 5MHz is the maximum clock-frequency, ie. the I2C bus frequency. > This is actually set to 100kHz for I2C0 in the DT: > > &i2c0 { > status = "okay"; > clock-frequency = <100000>; <---- > ... > }; > > 50MHz is the "fixed-clock" frequency, that is the clock feeding the I2C > IP block: > > i2c_ic_clk: i2c-clock { > compatible = "fixed-clock"; > clock-frequency = <50000000>; <----- > #clock-cells = <0>; > }; > > My guess is that the bot confused the clock-frequency parameter for the bus > clock (SCL) with the i2c-ic-clock value for the controller itself during the > checks. > > Do you agree with this or am I misunderstanding the error ? > > If I lower the fixed-clock frequency to eg. 100kHz, the error is gone. But I > guess the 5MHz limit should probably not apply to the input clock? Heh, I know why that's happening - it's your node name. The pattern for i2c controllers is "^i2c(@.*)?": https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/i2c/i2c-controller.yaml Rob co-incidentally (or maybe not) put out a patch for fixed-frequency clock names, suggesting using clock as a prefix: https://lore.kernel.org/all/20240425183810.3079069-1-robh@xxxxxxxxxx/ If we switched to that format, I believe your problem goes away. Cheers, Conor.
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