On Tue, 03 Dec 2019, Geert Uytterhoeven wrote: > Hi Chris, > > CC Lee (for clock-critical) > > On Tue, Dec 3, 2019 at 7:58 PM Chris Brandt <Chris.Brandt@xxxxxxxxxxx> wrote: > > On Tue, Dec 3, 2019, Geert Uytterhoeven wrote: > > > > + reg = <0x3fefa000 0x100>, <0x18000000 > > > > + 0x4000000>; > > > > > > The second region conflicts with the XIP flash@18000000 in > > > arch/arm/boot/dts/r7s72100-gr-peach.dts. > > > Yes, I know it is the same device ;-) > > > > Is that just an FYI?? Or do you have some suggestion?? > > Can the flash subnode be compatible with "mtd-rom", even if the parent node > is kept disabled? > > > > > + clock-critical = <4>; /* spibsc0 */ > > > > > > Iff we go this clock-critical route, I think this should be specified in the > > > board-specific .dts instead of in the SoC-specific .dtsi. > > > > OK, that's fine. It makes more sense to be in the .dts because it's a board > > design decision. I will remove it from the patch. > > > > The one 'tricky' thing is that the <4> is the index into the number of clocks. > > > > So in the Renesas BSP where it includes the VDC5 LCD controllers, > > > > clock-output-names = "i2c0", "i2c1", "i2c2", "i2c3", "vdc50", "vdc51", "spibsc0", "spibsc1"; > > > > the <4> needs to become a <6>. > > Unless you pass "clkidx" instead of "i" to of_clk_detect_critical() in [1], > and use "clock-critical = <R7S72100_CLK_SPIBSC0>" in DT? > > Unfortunately the exact semantics of clock-critical were never documented. > Lee? /** * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree * @np: Device node pointer associated with clock provider * @index: clock index * @flags: pointer to top-level framework flags * * Detects if the clock-critical property exists and, if so, sets the * corresponding CLK_IS_CRITICAL flag. * * Do not use this function. It exists only for legacy Device Tree * bindings, such as the one-clock-per-node style that are outdated. * Those bindings typically put all clock data into .dts and the Linux * driver has no clock data, thus making it impossible to set this flag * correctly from the driver. Only those drivers may call * of_clk_detect_critical from their setup functions. * * Return: error code or zero on success */ If this meets the criteria, the API is pretty simple/self explanatory. What are you having trouble with? > Thanks! > > [1] "[PATCH 1/6] clk: renesas: mstp: Add critical clock from device > tree support" > https://lore.kernel.org/linux-renesas-soc/20191203034519.5640-2-chris.brandt@xxxxxxxxxxx/ > > > Gr{oetje,eeting}s, > > Geert > -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
