On Wed, 2020-08-26 at 12:32 +0200, Matthias Schiffer wrote: > On Tue, 2020-08-25 at 14:16 -0300, Fabio Estevam wrote: > > On Tue, Aug 25, 2020 at 11:40 AM Matthias Schiffer > > <matthias.schif...@ew.tq-group.com> wrote: > > > > > Makes sense. Does the following logic sound correct? > > > > > > - If num-cs is set, use that (and add it to the docs) > > > > I would not add num-cs to the docs. As far as I can see there is no > > imx dts that uses num-cs currently. > > But the previous platform data that was removed in 8cdcd8aeee281 > ("spi: > imx/fsl-lpspi: Convert to GPIO descriptors") set different values for > different boards. So maybe some DTS should be using num-cs? > > > > > > > - If num-cs is unset, use the number of cs-gpios > > > - If num-cs is unset and no cs-gpios are defined, use a driver- > > > provided > > > default > > > > > > > > > I'm not sure if 3 is a particularly useful default either, but it > > > seems > > > it was chosen to accommodate boards that previously set this via > > > platform data. All SoCs I've checked (i.MX6Q/DL, i.MX6UL, i.MX7) > > > have 4 > > > internal CS pins per ECSPI instance, so maybe the driver should > > > use > > > that as its default instead? > > > > I think it is time to get rid of i.MX board files. I will try to > > work > > on this when I have a chance. > > > > bout using 4 as default chip select number, please also check some > > older SoCs like imx25, imx35, imx51, imx53, etc > > Hmm, I just checked i.MX28, and it has only 3 chip selects per > instance.
Ah sorry, I got confused, the i.MX28 has a different SPI IP.