On Tue, Nov 23, 2021 at 09:16:14PM -0500, Sean Anderson wrote: > On 11/22/21 10:02 PM, Peng Fan (OSS) wrote: > > > 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 <[email protected]> > > > > > > > > > > > > > > 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 <[email protected]> > > > > > > > Signed-off-by: Peng Fan <[email protected]> > > > > > > > --- > > > > > > > > > > > > > > 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. > > Hm. Well perhaps we can designate a specific return code to indicate > that we have a valid clock ID but it is just unimplemented. So in your > driver you would do > > ulong my_get_rate(struct clk *clk) > { > switch (clk->id) { > case MY_CLK: > ... > default: > if (clk->id < MY_CLK_MAX) > return -ENOSYS; > else > return -EINVAL; > } > } > > and then the clock rate assignment would see -ENOSYS and go on its merry > way.
Or even just have the driver that matches on "fsl,imx8mp-ccm" have a
log_debug("Leaving clocks as-is, OS will handle them\n");
and returning success?
--
Tom
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