Re: (EXT) Re: (EXT) Re: (EXT) Re: (EXT) Re: (EXT) Re: [PATCH 2/2] ARM: dts: imx6qdl: tqma6: minor fixes

2020-08-26 Thread Fabio Estevam 
On Wed, Aug 26, 2020 at 10:13 AM Matthias Schiffer
 wrote:

> Using GPIOs for chipselect would require different pinmuxing. Also, why
> use GPIOs, when the SPI controller has this built in?

In the initial chips with the ECSPI controller there was a bug with
the native chipselect controller and we had to use GPIO.

Re: (EXT) Re: (EXT) Re: (EXT) Re: (EXT) Re: (EXT) Re: [PATCH 2/2] ARM: dts: imx6qdl: tqma6: minor fixes

2020-08-26 Thread Matthias Schiffer 
On Wed, 2020-08-26 at 10:01 -0300, Fabio Estevam wrote:
> On Wed, Aug 26, 2020 at 8:54 AM Matthias Schiffer
>  wrote:
> 
> > Before 8cdcd8aeee281, num_chipselect was set to 3 for spi0 and to 1
> > for
> > spi1 in arch/arm/mach-imx/mach-mx31lite.c. My understanding is that
> > it
> > would make sense to add this as num-cs to
> > arch/arm/boot/dts/imx31-lite.dts.
> 
> Or just pass cs-gpios instead?

Using GPIOs for chipselect would require different pinmuxing. Also, why
use GPIOs, when the SPI controller has this built in?

Re: (EXT) Re: (EXT) Re: (EXT) Re: (EXT) Re: [PATCH 2/2] ARM: dts: imx6qdl: tqma6: minor fixes

2020-08-26 Thread Fabio Estevam 
On Wed, Aug 26, 2020 at 8:54 AM Matthias Schiffer
 wrote:

> Before 8cdcd8aeee281, num_chipselect was set to 3 for spi0 and to 1 for
> spi1 in arch/arm/mach-imx/mach-mx31lite.c. My understanding is that it
> would make sense to add this as num-cs to
> arch/arm/boot/dts/imx31-lite.dts.

Or just pass cs-gpios instead?

Re: (EXT) Re: (EXT) Re: (EXT) Re: (EXT) Re: [PATCH 2/2] ARM: dts: imx6qdl: tqma6: minor fixes

2020-08-26 Thread Matthias Schiffer 
On Wed, 2020-08-26 at 07:59 -0300, Fabio Estevam wrote:
> Hi Matthias,
> 
> On Wed, Aug 26, 2020 at 7:32 AM Matthias Schiffer
>  wrote:
> 
> > 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?
> 
> Could you provide an example of an imx dts that should use num-cs?

I'm not sure, does anything break when num_chipselect is set too high?

Before 8cdcd8aeee281, num_chipselect was set to 3 for spi0 and to 1 for
spi1 in arch/arm/mach-imx/mach-mx31lite.c. My understanding is that it
would make sense to add this as num-cs to
arch/arm/boot/dts/imx31-lite.dts.