On Wed, 2016-06-29 at 21:33 +0200, Arnd Bergmann wrote: > On Wednesday, June 29, 2016 8:51:44 PM CEST Arend Van Spriel wrote: > > > Typical wifi devices will have some sort of non volatile storage > > > on board to not only store the ethernet(mac) address, but also > > > to contain e.g. info about the antenna gain so that the firmware > > > and/or the driver can take the antenna gain into account and > > > ensure > > > that they never exceed the maximum allowed broadcast strength. > > > > > > However on some embedded devices there is no non-volatile storage > > > for the wifi (for cost reasons) and instead this configuration > > > info > > > (which is board / pcb specific) is loaded in the form of a > > > file which contains the contents which would normally be in the > > > non-volatile storage. > > > > > > Since we are dealing with a per-board config-file here, which is > > > loaded from the os filesystem we really need to specify a > > > basename > > > here as the list of possible boards is endless, so we cannot > > > have a lookup table in the driver. > > > > As Jonas mentioned the general principle of device tree is to be > > agnostic with regards to OS and/or driver as you undoubtedly know. > > His > > proposal seems like a usable solution for your problem while > > complying > > to the device tree principle. So instead of overriding the default > > brcmfmac should modify it when dt specifies the "module" property, > > ie: > > > > no "module" in DT: nvram filename = brcm/brcmfmac43362- > > sdio.txt > > "module=ap6210" in DT: nvram filename = brcm/brcmfmac43362- > > ap6210.txt > > > > By the way, the example in the bindings file does not seem to > > specify a > > basename, but path+basename+fileext. > > What is the size of this nvram file? As it's board specific, I wonder > if we can simply include it inside of the DT verbatim. I remember > doing that (in the pre-dtb days, on real open firmware) for the > "spidernet" > ethernet driver. It contains a bit too much info: This is what CubieTruck requires: http://dl.cubieboard.org/public/Cubieboard/benn/firmware/ap6210/nvram_a p6210.txt -- 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
