> Subject: Re: [PATCH V2] clk: introduce u-boot,ignore-clk-defaults > > On Mon, Nov 22, 2021 at 11:33:27AM +0800, Peng Fan (OSS) wrote: > > + Rob > > > > On 2021/11/20 20:57, Tom Rini wrote: > > > On Sat, Nov 20, 2021 at 12:10:54PM +0000, Peng Fan (OSS) wrote: > > > > > Subject: [PATCH V2] clk: introduce u-boot,ignore-clk-defaults > > > > > > > > > > From: Peng Fan <peng....@nxp.com> > > > > > > > > > > Current code has a force clk_set_defaults in multiple stages, > > > > > U-Boot reuse the same device tree and Linux Kernel device tree, > > > > > but we not register all the clks as Linux Kernel, so > > > > > clk_set_defaults will fail and cause the clk provider registeration > > > > > fail. > > > > > > > > > > So introduce a new property to ignore the default settings which > > > > > could be used by any node that wanna ignore default settings. > > > > > > > > > > Reviewed-by: Simon Glass <s...@chromium.org> > > > > > Signed-off-by: Peng Fan <peng....@nxp.com> > > > > > --- > > > > > > > > > > V2: > > > > > Add R-b tag > > > > > Tom, Simon > > > > > After a thought, I think still put it as a u-boot thing. > assigned-clock-x is > > > > > actually Linux specific, however I could not add the new property > to Linux, > > > > > because we are supporting SystemReady-IR, we need the > > > > > assigned-clock-x property > > > > > in linux working and ignore it in U-Boot. > > > > > > > > Any more thoughts? > > > > > > Just my continued request that you treat this as generic and submit > > > the binding upstream so it can be in the device tree for the platform. > > > > > > > As Sean said, this is to serve cast that linux and U-Boot use the same > > device tree, I mean U-Boot runtime export device tree to linux for > > SR-IR (system-ready IR) booting. > > > > Linux needs assigned-clocks to some reason, but U-Boot not need that > > because the driver not added the support or not a must to have that. > > > > Because assigned-clocks failure in U-Boot will cause probe fail now, > > the device driver will report failure. > > > > You mean rename this to "ignore-clk-defaults" or keep > > "u-boot,ignore-clk-defauls" or "firmware,ignore-clk-defaults" to linux > > device tree binding? > > > > I could try to send to linux kernel with "firmware" as a prefix. > > What I mean is that first I'm not seeing the description of the property as > being clear enough, either in commit message or the binding itself. > That's why in my mind I keep seeing this as "we set the properties > linux,assigned-clocks and u-boot,ignore-clk-defaults" and I don't know why > we need both. Is there not something we can do based on seeing > linux,assigned-clocks ? Showing something that makes use of the property > you're wishing to add would be helpful. In fact, some specific dts snippets > would be helpful to understand what's going on here.
clk: clock-controller@30380000 { compatible = "fsl,imx8mp-ccm"; reg = <0x30380000 0x10000>; #clock-cells = <1>; clocks = <&osc_32k>, <&osc_24m>, <&clk_ext1>, <&clk_ext2>, <&clk_ext3>, <&clk_ext4>; clock-names = "osc_32k", "osc_24m", "clk_ext1", "clk_ext2", "clk_ext3", "clk_ext4"; assigned-clocks = <&clk IMX8MP_CLK_A53_SRC>, <&clk IMX8MP_CLK_A53_CORE>, <&clk IMX8MP_CLK_NOC>, <&clk IMX8MP_CLK_NOC_IO>, <&clk IMX8MP_CLK_GIC>, <&clk IMX8MP_CLK_AUDIO_AHB>, <&clk IMX8MP_CLK_AUDIO_AXI_SRC>, <&clk IMX8MP_CLK_IPG_AUDIO_ROOT>, <&clk IMX8MP_AUDIO_PLL1>, <&clk IMX8MP_AUDIO_PLL2>; assigned-clock-parents = <&clk IMX8MP_SYS_PLL1_800M>, <&clk IMX8MP_ARM_PLL_OUT>, <&clk IMX8MP_SYS_PLL2_1000M>, <&clk IMX8MP_SYS_PLL1_800M>, <&clk IMX8MP_SYS_PLL2_500M>, <&clk IMX8MP_SYS_PLL1_800M>, <&clk IMX8MP_SYS_PLL1_800M>; assigned-clock-rates = <0>, <0>, <1000000000>, <800000000>, <500000000>, <400000000>, <800000000>, <400000000>, <393216000>, <361267200>; u-boot,ignore-clk-defaults; }; The above node is that I wanna have in U-Boot device tree. This node is same as the one used in linux device tree except the new property introduced here. In i.MX U-Boot, we not support the clks here in the clk driver, but linux needs the assigned-clocks property, so I could not delete it because U-Boot runtime export the device tree to Linux. So add a new property here for U-Boot specific usage, if the property is there, U-Boot ignore the assigned-clock settings for a node. I hope this is clear and please suggest what to do next. Thanks, Peng. > > Second, if we need a new property here then yes, it goes upstream and you > put u-boot,has-not-clk-foo or firmware,has-not-clk-foo or whatever in the > boards dts file. > > -- > Tom