Hi Tomeu, On Mon, Sep 7, 2015 at 2:23 PM, Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> wrote: > Walks the OF tree up and finds the closest ancestor that has a struct > device associated with it, probing it if isn't bound to a driver yet. > > The above should ensure that the dependency represented by the passed OF > node is available, because probing a device should cause its descendants > to be probed as well (when they get registered). > > Subsystems can use this when looking up resources for drivers, to reduce > the chances of deferred probes because of the probing order of devices. > > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> > --- > > Changes in v4: > - Rename of_platform_probe to of_device_probe > - Use device_node.device instead of device_node.platform_dev > > Changes in v3: > - Set and use device_node.platform_dev instead of reversing the logic to > find the platform device that encloses a device node. > - Drop the fwnode API to probe firmware nodes and add OF-only API for > now. I think this same scheme could be used for machines with ACPI, > but I haven't been able to find one that had to defer its probes because > of the device probe order. > > Changes in v2: None > > drivers/of/device.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++ > drivers/of/platform.c | 2 ++ > include/linux/of_device.h | 3 +++ > 3 files changed, 63 insertions(+) > > diff --git a/drivers/of/device.c b/drivers/of/device.c > index 8b91ea241b10..c32ac7b6fbe2 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -286,3 +286,61 @@ int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) > > return 0; > } > + > +/** > + * of_device_probe() - Probe device associated with OF node > + * @np: node to probe > + * > + * Probe the device associated with the passed device node. > + */ > +void of_device_probe(struct device_node *np) > +{ > + struct device_node *target; > + struct device *dev = NULL; > + > + if (!of_root || !of_node_check_flag(of_root, OF_POPULATED_BUS)) > + return; > + > + if (!np) > + return; > + > + of_node_get(np); > + > + /* Find the closest ancestor that has a device associated */ > + for (target = np; > + !of_node_is_root(target); > + target = of_get_next_parent(target)) > + if (target->device) { > + dev = target->device; > + break; > + } > + > + of_node_put(target); > + > + if (!dev) { > + pr_warn("Couldn't find a device for node '%s'\n", > + of_node_full_name(np)); This is triggered for all devices with clocks instantiated through CLK_OF_DECLARE(). E.g. on r8a7791/koelsch ("... | sort | uniq -c"): 1 Couldn't find a device for node '/clocks/audio_clk_a' 1 Couldn't find a device for node '/clocks/audio_clk_b' 1 Couldn't find a device for node '/clocks/audio_clk_c' 2 Couldn't find a device for node '/clocks/cpg_clocks@e6150000' 1 Couldn't find a device for node '/clocks/m2_clk' 2 Couldn't find a device for node '/clocks/mstp0_clks@e6150130' 34 Couldn't find a device for node '/clocks/mstp10_clks@e6150998' 2 Couldn't find a device for node '/clocks/mstp1_clks@e6150134' 2 Couldn't find a device for node '/clocks/mstp2_clks@e6150138' 10 Couldn't find a device for node '/clocks/mstp3_clks@e615013c' 3 Couldn't find a device for node '/clocks/mstp5_clks@e6150144' 8 Couldn't find a device for node '/clocks/mstp7_clks@e615014c' 4 Couldn't find a device for node '/clocks/mstp8_clks@e6150990' 22 Couldn't find a device for node '/clocks/mstp9_clks@e6150994' 1 Couldn't find a device for node '/clocks/pcie_bus_clk' Corresponding DTS is arch/arm/boot/dts/r8a7791.dtsi. > + return; > + } Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html