On Thu, 2014-10-30 at 10:36 +0100, Hans de Goede wrote:
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 ?
I was imagining a function which would take the string "uart0" and would call sunxi_gpio_set_cfgpin with whatever values that would entail in order to make uart0 work, not one which would try and return something that the caller would then use.
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.
I believe we currently statically use either portb or portf (I've not looked up which, IIRC it changed recently, but I don't recall which way), so my proposed function would just DTRT. Of course if we ever find we need something more dynamic then we would have to do a proper pinmux implementation (or at least something closer to a proper one)
Ian.