On Wed, Aug 11, 2021 at 2:17 PM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > > On Tue, Aug 3, 2021 at 9:23 PM Robert Marko <robert.marko@xxxxxxxxxx> wrote: > > > The pins that this driver wants to expose are used for SFP-s only, > > they are provided by the Lattice CPLD which also does other things. > > > > Linux has a generic SFP driver which is used to manage these SFP > > ports, but it only supports GPIO-s, it has no concept of anything else. > > Since the driver is fully generic, I have no idea how could one extend it > > to effectively handle these pins internally, especially since I have more > > switches that use the CPLD for SFP-s as well, even for 48 ports and 192 > > pins for them. > > Which file is this driver in so I can look? Hi Linus, Sorry for the late reply. Sure, here is the generic Linux driver that is used for SFP handling: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/phy/sfp.c?h=v5.14-rc7 > > Maybe it is not a good idea to look for generic code just because > it is convenient? I have had this problem before with GPIO, along > the lines "lemme just do this dirty thing this one time because it > is so convenient for me" (more or less) and the answer is still > "no". > > Can you either augment the driver to handle a regmap with bit indices > instead or write a new similar driver for that or refactor it some other > way? > > It is not a simple solution to your problem, but it might be the right > solution even if it means some more work. I understand your position, believe me, I spend some time looking at what would be the logical way for these switches. But I see no way how could the SFP driver be extended in a generic way that would allow supporting different register layouts when it comes to pins. > > > GPIO regmap works perfectly for this as its generic enough to cover all of > > these cases. > > Yeah but it might be the wrong thing to do even if it is simple > to use and works. > > > CPLD also provides pins to test the port LED-s per color as well, > > but I have chosen not to expose them so far. > > Have you considered > Documentation/devicetree/bindings/leds/register-bit-led.txt Yeah, but unfortunately in this case it wont work as the LED-s are for debugging/test purposes only and you first need to switch the CPLD out of it interpreting the LED state with a BIT flip. Regards, Robert > > > > If it is a regmap in Linux then that is fine, just pass the regmap > > > around inside the kernel, OK finished. But really that is an OS > > > detail. > > > > Yes, its regmap but I cant really pass it to the SFP driver as I don't have > > special driver handling the SFP but rather the generic kernel one. > > It only knows how to handle GPIO-s. > > Of course you have to program it. If I know which driver it > is it is easier to provide architecture ideas. > > Yours, > Linus Walleij -- Robert Marko Staff Embedded Linux Engineer Sartura Ltd. Lendavska ulica 16a 10000 Zagreb, Croatia Email: robert.marko@xxxxxxxxxx Web: www.sartura.hr
