Hi Stefano,
On 10/01/2013 07:49 AM, Stefano Babic wrote:
Hi Eric,
On 01/10/2013 16:26, Eric Nelson wrote:
I'm not sure where you're seeing this in the RM, but in order to read the pad state when not configured as an input, the SION bit needs to be set in the pad mux register on i.MX51/53.
I have checked inside the "37.3.2.2 GPIO Write" for i.MX53 and " 35.4.2.1 Read Value from Pad" for i:MX51, I have not read anything about SION. If someone has found where it is described, please mail !
That documentation seems to imply that there's no dependency (i.e. there's no reference to SION), but I think that's an omission.
FWIW, this also works when not muxed as a GPIO, which is really handy for verifying that a PWM is toggling, et cetera.
Well, if you have directly tested it, it is better proofed as by the manuals..then we need the same fix for i.MX51/i.MX53, too.
I've tested this many times, since it's a really handy way of debugging hardware setups.
That said, I'm not sure that there's a huge difference between a single patch or multiple patches for each arch unless there's some functionality dependent on being able to read the actual value of a pin configured as a GPIO output.
Did I miss something in this thread that does actually require that ability? It seems a pretty obscure thing in the normal case to drive an output without confidence that it will succeed.
Regards,
Eric