Hi, On 10/30/2014 10:08 AM, Ian Campbell wrote: > On Wed, 2014-10-29 at 13:28 -0600, Simon Glass wrote: >>> In the meantime could we somehow replace/augment the #ifdef chain in >>> gpio_init with something keyed off the stdout alias perhaps? >> >> Tegra has code to convert a device interrupt number (which uniquely >> identifies a peripheral in that SoC) to an internal peripheral ID, >> then these is a function which can enable a peripheral given the ID >> (funcmux). In some cases you could have multiple options for the >> funcmux, but there is no easy way to support this. > > I think that although there are multiple options for some functions > (UARTs come to mind) we haven't yet found the need to make any dynamic > choices, so it's all static right now. > >> But this approach >> might be good enough for sunxi. We can easily write the function to >> enable the pins for a particular port, and this could go in >> arch/arm/...sunxi/ perhaps. > > I'm ok with it so long as it isn't going to stand in the way of proper > dt based pinmux in the future. > > One way to help with that might be to use the allwinner,function > property in DT as the funcmux name. > > Hans, what do you think?
I'm not 100% sure what you're suggesting here, are you suggesting to have a 1:1 mapping between function names as stored in allwinner,function in dts and the value to pass to sunxi_gpio_set_cfgpin ? This is not going to fly very far, e.g. the "uart0" function has cfg value of 2 on portb while it has a value of 4 on portf. So we will really need a sunxi specific function to go from port-no + allwinner,function-string to a sunxi_gpio_set_cfgpin function. I think the best thing we can do to not make this function too big is do 3 things: 1) Have a table which only contains mapping where the cfg value is not 2, most ipblocks have a "primary" gpio port they are intended to be used with, and this usage maps to a cfg value of 2, and most designs use this, so have a list of exceptions and return 2 otherwise, this will make debugging of issues where the mux is not setup a bit harder, but it will keep things a lot smaller. 2) Only but things in there which are actually used by boards, or we expect to need in the near future. 3) Have #ifndef CONFIG_SPL_BUILD .. #endif around anything but mmc / uart entries in that table. Together those should keep things small enough for the SPL. Regards, Hans _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
