On 29 July 2015 at 17:27, Rob Herring <robherring2@xxxxxxxxx> wrote: > On Wed, Jul 29, 2015 at 6:20 AM, Tomeu Vizoso > <tomeu.vizoso@xxxxxxxxxxxxx> wrote: >> On 29 July 2015 at 08:14, Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> wrote: >>> On 28 July 2015 at 17:31, Rob Herring <robherring2@xxxxxxxxx> wrote: >>>> On Tue, Jul 28, 2015 at 8:54 AM, Tomeu Vizoso >>>> <tomeu.vizoso@xxxxxxxxxxxxx> wrote: >>>>> On 28 July 2015 at 15:39, Rob Herring <robherring2@xxxxxxxxx> wrote: >>>>>> On Tue, Jul 28, 2015 at 8:19 AM, Tomeu Vizoso >>>>>> <tomeu.vizoso@xxxxxxxxxxxxx> wrote: >>>>>>> From an arbitrary node in the tree, find the enclosing node that >>>>>>> corresponds to a platform device, as registered by >>>>>>> of_platform_populate(). > > [...] > >>>>> If I had a way to get, say, a i2c device from its fwnode then I would >>>>> just need to make sure that a device's parent is probed before probing >>>>> it and everything would be cleaner in the OF case. >>>> >>>> If you have the struct device from the device_node, then you should be >>>> able to do this, right? >>> >>> Yes, if I could go back from the device_node to the struct device that >>> was registered from it, for all buses, then all this would be much >>> simpler and more robust. It would basically work like in the ACPI >>> case. >>> >>> I will play with this idea. >>> >>>>>> That is probably not the >>>>>> most efficient search, but we could fix that. We could add struct >>>>>> device ptr to struct device_node and check without searching for >>>>>> example. >>>>> >>>>> That would be great, but I thought there was an issue with a OF node >>>>> being able to be related to more than one struct device (but I haven't >>>>> found this myself yet). >>>> >>>> I think it pretty much should be one to one. I'm not aware of any >>>> examples where that is not the case. This function would already be >>>> broken if you could have more than one struct device. >>> >>> Well, for platform devices we currently know that there can only be >>> one struct device for a given device_node, but that's not so clear for >>> other devices. >> >> Just found this case: >> >> http://lxr.free-electrons.com/source/drivers/spi/spi-tegra114.c#L1124 >> >> Looks like SPI master devices point to the same device_node as the >> platform device that registers them. > > I don't think this is a problem. The device ptr would only point to > the platform device. Nothing else is going to know about the ptr, > modify it nor expect that it points to the same struct device that > contains the of_node ptr. > > So I think any instances of struct device like this are ones you don't > care about for purposes of probe dependencies. Ok, I think I got it now. This is what I came up with and works fine on all the boards I'm testing with: diff --git a/drivers/of/platform.c b/drivers/of/platform.c index 89c5cd513027..e14518b5e1ce 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -192,6 +192,8 @@ static struct platform_device *of_platform_device_create_pdata( goto err_clear_flag; } + np->platform_dev = dev; + return dev; err_clear_flag: @@ -501,59 +503,29 @@ void of_platform_depopulate(struct device *parent) } EXPORT_SYMBOL_GPL(of_platform_depopulate); /** * of_platform_device_find() - Find nearest ancestor that is a platform device * @np: node to find platform device for * - * Walks the tree up and finds the closest ancestor that has match data and - * either is at the root of the tree or is a child of a simple memory mapped - * bus. + * Walks the OF tree up and finds the closest ancestor that has a platform + * device associated with it. * * Returns such a device, or NULL if none could be found. */ struct device *of_platform_device_find(struct device_node *np) { struct device_node *target; - struct platform_device *pdev; + struct platform_device *pdev = NULL; of_node_get(np); for (target = np; !of_node_is_root(target); target = of_get_next_parent(target)) - if (of_is_platform(target)) + if (target->platform_dev) { + pdev = target->platform_dev; break; - - pdev = of_find_device_by_node(target); + } of_node_put(target); Thanks, Tomeu > Rob > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- 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
