On 4/6/20 4:20 PM, Ahmad Fatoum wrote: > Hello, > > On 4/6/20 2:33 PM, Srinivas Kandagatla wrote: >> >> >> On 23/03/2020 15:28, Ahmad Fatoum wrote: >>> The nvmem cell binding applies to objects which match "^.*@[0-9a-f]+$", >>> but so far the driver has matched all objects and failed if they didn't >>> have the expected properties. >>> >>> The driver's behavior in this regard precludes future extension of >>> EEPROMs by child nodes other than nvmem and clashes with the barebox >>> bootloader binding that extends the fixed-partitions MTD binding to >>> EEPROMs as it tries to interpret the "fixed-partitions"-compatible >>> partitions node as a nvmem cell. >>> >>> Solve this issue by skipping all subnodes that don't contain an @. >>> >>> This still allows for cell names like `partitions@0,0', but this >> NACK.. thats nasty hack! >> Its standard practice as per device tree specs to have nodes name as "node-name@unit-address" >> >> Ref: https://github.com/devicetree-org/devicetree-specification/releases/download/v0.3/devicetree-specification-v0.3.pdf > > I didn't say otherwise. I just argued if we verify there's a @ symbol in the > node name, before considering whether it is a NVMEM cell, we will skip fixed-partitions > while adhering to the NVMEM cell binding. > >>> is much less likely to cause future collisions. >> >> There have been discussions on this topic in the past at: >> >> https://patchwork.ozlabs.org/patch/890741/ >> >> We need to come up with a better solution! > > Thanks for the link, I didn't find it when I searched whether this has > come up before. > > As you probably noticed, your suggested approach there wouldn't work for me though, > because this time it can't be worked around in the MTD driver. > If the suggestion here is not palatable, how do you think about (in > my preferred order): > > - If the cell has a compatible node, it must be "nvmem-cell". > Otherwise, a cell with a compatible node is skipped. > > - Adding a nvmem cell container with a compatible and making support for > the old binding configurable > > - Skipping cells that are malformed and lack a reg = < > property _without_ > error gentle ping. I can prepare another patch if you indicate which approach you'd prefer. > > Cheers > Ahmad > >> >> --srini >> >>> >>> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> >>> --- >>> v1 -> v2: >>> use ->full_name instead of ->name as to not break existing correct >>> cells (Christian) >>> --- >>> drivers/nvmem/core.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c >>> index ef326f243f36..f051051fb1a8 100644 >>> --- a/drivers/nvmem/core.c >>> +++ b/drivers/nvmem/core.c >>> @@ -278,6 +278,8 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem) >>> parent = dev->of_node; >>> for_each_child_of_node(parent, child) { >>> + if (!strchr(kbasename(child->full_name), '@')) >>> + continue; >>> addr = of_get_property(child, "reg", &len); >>> if (!addr || (len < 2 * sizeof(u32))) { >>> dev_err(dev, "nvmem: invalid reg on %pOF\n", child); >>> >> > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
