Linus ? On Wed, Jan 28, 2015 at 07:54:44PM +0100, Robert Jarzmik wrote: > Felipe Balbi <balbi@xxxxxx> writes: > > >> nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset"); > >> if (gpiod_is_active_low(nop->gpiod_reset)) > >> gpiod_direction_output(nop->gpiod_reset, GPIOD_OUT_LOW); > >> else > >> gpiod_direction_output(nop->gpiod_reset, GPIOD_OUT_HIGH); > > > > won't the descriptor itself handle that for us ? Linus ? > > > > I want to hear from Linus W first. > > Yes, so do I. > > Let's add a bit of context for Linus : > 1) In the past, the driver was doing a ; > gpio_request_one() > -> gpiod_direction_output_raw() > 2) After the conversion to gpio descriptors, it is doing : > gpiod_get_optional(dev, "reset"); > -> ... > -> __gpiod_get_index(dev, "reset", 0, 0) > -> this of course doesn't call gpiod_direction() > > The problem is that we cannot call: > gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); > because we don't know before the call if the GPIO is active high or low. The > former gpio_request_one() was clever and did a gpio_direction_output_raw(.., > (flags & GPIOF_INIT_HIGH) ? 1 : 0). > > So what is the right way out ? : > - is it to call gpiod_direction_output(nop->gpiod, 0) just after > gpiod_get_optional() in probe code ? > - is it when the gpio is used to call gpiod_direction_output(gpiod, x) instead > of gpiod_set_value() ? > - is it something else ? > > Cheers. > > -- > Robert -- balbi
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