On Mon, Jul 27, 2015 at 09:34:41AM -0700, Andrew Bresticker wrote: > On Mon, Jul 27, 2015 at 5:11 AM, Sifan Naeem <[email protected]> wrote:
> > spfi_setup may be called many times bye the spi framework, but > > gpio_request_one can only be called once without freeing, repeatedly > > calling gpio_request_one will cause an error to be thrown, which causes > > the request to spi_setup to be marked as failed. > > We can simply use gpio_direction_output to set the direction of the > > gpio instead of gpio_request_one to put the gpio in to initial state, > > after which the spi framework can control the chipselect line via gpio > > using gpio_set_value. > I don't think we want to leave the CS GPIOs un-requested. Instead, we > could either request them all at probe() time (and then set direction > in setup()) or have a per-spi_device flag that indicates whether or > not the GPIO has been requested. Not requesting the GPIOs at all would just be a straight up bug.
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