need help getting SPI controller working on 405EX

need help getting SPI controller working on 405EX

[Nathan French]

Hi, I am trying to add support for the 405EX's SPI controller on a Kilauea board.  I've added the below to the device tree (under plb/opb/):

[nfrench@nfrench-laptop linux-2.6-denx]$ diff -C2 arch/powerpc/boot/dts/kilauea.dts spi.dts
*** arch/powerpc/boot/dts/kilauea.dts	2009-05-05 15:56:16.000000000 -0700
--- spi.dts	2009-08-06 08:42:19.000000000 -0700
***************
*** 207,210 ****
--- 207,221 ----
  				#size-cells = <0>;
  			};
+             
+             SPI0: spi@ef600600 {
+                 cell-index = <0>;
+                 compatible = "ibm,spi-405ex", "ibm,spi";
+                 reg = <ef600600 6>;
+                 interrupts = <8 4>;
+                 interrupt-parent = <&UIC0>;
+                 mode = "cpu";
+             };
  
  			RGMII0: emac-rgmii@ef600b00 {

I've also compiled my kernel with the following enabled:

        CONFIG_SPI=y
        CONFIG_SPI_MASTER=y
        CONFIG_SPI_SPIDEV=y

I see this make it into the device tree after boot:

        [root@10.2.3.28 /]$ find /proc/device-tree/ | grep spi
        /proc/device-tree/plb/opb/spi@ef600600
        /proc/device-tree/plb/opb/spi@ef600600/name
        /proc/device-tree/plb/opb/spi@ef600600/mode
        /proc/device-tree/plb/opb/spi@ef600600/interrupt-parent
        /proc/device-tree/plb/opb/spi@ef600600/interrupts
        /proc/device-tree/plb/opb/spi@ef600600/reg
        /proc/device-tree/plb/opb/spi@ef600600/compatible
        /proc/device-tree/plb/opb/spi@ef600600/cell-index

But I don't see any /dev/spidev* devices created or any mention of SPI
at boot time.  I'm starting to suspect that I don't have the kernel
configured right, otherwise I would see at least the SPI driver
complaining about something, right?

Thanks,

Nathan French

Re: need help getting SPI controller working on 405EX

[Lorenz Kolb]

Nathan French wrote:
> Hi, I am trying to add support for the 405EX's SPI controller on a Kilauea board.  I've added the below to the device tree (under plb/opb/):
> 
> [nfrench@nfrench-laptop linux-2.6-denx]$ diff -C2 arch/powerpc/boot/dts/kilauea.dts spi.dts
> *** arch/powerpc/boot/dts/kilauea.dts	2009-05-05 15:56:16.000000000 -0700
> --- spi.dts	2009-08-06 08:42:19.000000000 -0700
> ***************
> *** 207,210 ****
> --- 207,221 ----
>   				#size-cells = <0>;
>   			};
> +             
> +             SPI0: spi@ef600600 {
> +                 cell-index = <0>;
> +                 compatible = "ibm,spi-405ex", "ibm,spi";
> +                 reg = <ef600600 6>;
> +                 interrupts = <8 4>;
> +                 interrupt-parent = <&UIC0>;
> +                 mode = "cpu";
> +             };
>   
>   			RGMII0: emac-rgmii@ef600b00 {
> 

That entry within the device tree will generally make the spi-"bus" 
known to Linux, that's ok so far.

> I've also compiled my kernel with the following enabled:
> 
>         CONFIG_SPI=y
>         CONFIG_SPI_MASTER=y
>         CONFIG_SPI_SPIDEV=y
> 
> I see this make it into the device tree after boot:
> 
>         [root@10.2.3.28 /]$ find /proc/device-tree/ | grep spi
>         /proc/device-tree/plb/opb/spi@ef600600
>         /proc/device-tree/plb/opb/spi@ef600600/name
>         /proc/device-tree/plb/opb/spi@ef600600/mode
>         /proc/device-tree/plb/opb/spi@ef600600/interrupt-parent
>         /proc/device-tree/plb/opb/spi@ef600600/interrupts
>         /proc/device-tree/plb/opb/spi@ef600600/reg
>         /proc/device-tree/plb/opb/spi@ef600600/compatible
>         /proc/device-tree/plb/opb/spi@ef600600/cell-index
> 
> But I don't see any /dev/spidev* devices created or any mention of SPI
> at boot time.  I'm starting to suspect that I don't have the kernel
> configured right, otherwise I would see at least the SPI driver
> complaining about something, right?

For getting spidev devices you have to add entries for an spidev device 
to your newly created spi-"bus". So what you are currently missing are 
the spidev child-nodes in the device tree.
As I'm currently cut off from some device to test, no guaranty that it 
will work, but your dts entry should look something like:

              SPI0: spi@ef600600 {
                  cell-index = <0>;
                  compatible = "ibm,spi-405ex", "ibm,spi";
                  reg = <ef600600 6>;
                  interrupts = <8 4>;
                  interrupt-parent = <&UIC0>;
                  mode = "cpu";

                  yourdevice@0 {
                      compatible = "spidev";
                      spi-max-frequency = <1000000>; /* what ever your 
max-freq. is */
                      reg = <0>; /* Chipselect-address */
                  };
              };

> 
> Thanks,
> 
> Nathan French

At least something similar worked for me some months ago (before we 
switched to a "real" driver for some custom peripheral).

Regards,

Lorenz

Re: need help getting SPI controller working on 405EX

[Nathan French]

Lorenz, thanks for the reply.

> For getting spidev devices you have to add entries for an spidev device 
> to your newly created spi-"bus". So what you are currently missing are 
> the spidev child-nodes in the device tree.
> As I'm currently cut off from some device to test, no guaranty that it 
> will work, but your dts entry should look something like:
> 
>               SPI0: spi@ef600600 {
>                   cell-index = <0>;
>                   compatible = "ibm,spi-405ex", "ibm,spi";
>                   reg = <ef600600 6>;
>                   interrupts = <8 4>;
>                   interrupt-parent = <&UIC0>;
>                   mode = "cpu";
> 
>                   yourdevice@0 {
>                       compatible = "spidev";
>                       spi-max-frequency = <1000000>; /* what ever your 
> max-freq. is */
>                       reg = <0>; /* Chipselect-address */
>                   };
>               };

This did not appear to have any effect.

> At least something similar worked for me some months ago (before we 
> switched to a "real" driver for some custom peripheral).

Did this work on a 4xx PowerPC platform?  Or something else?  I've been
told that there is no SPI driver for 4xx.  If you have done this on 4xx
then I'm very interested.

Thanks,

Nathan

Re: need help getting SPI controller working on 405EX

[Stefan Roese]

On Monday 10 August 2009 18:07:15 Nathan French wrote:
> > At least something similar worked for me some months ago (before we
> > switched to a "real" driver for some custom peripheral).
>
> Did this work on a 4xx PowerPC platform?  Or something else?  I've been
> told that there is no SPI driver for 4xx.  If you have done this on 4xx
> then I'm very interested.

The 4xx SPI driver is (finally) queued for 2.6.32. So you either need to 
manually apply it now or wait a while.

Best regards,
Stefan

Re: need help getting SPI controller working on 405EX

[Nathan French]

This is good news.  Can you point me towards the patch for that?

Nathan

On Tue, 2009-08-11 at 01:44 -0400, Stefan Roese wrote:
> On Monday 10 August 2009 18:07:15 Nathan French wrote:
> > > At least something similar worked for me some months ago (before we
> > > switched to a "real" driver for some custom peripheral).
> >
> > Did this work on a 4xx PowerPC platform?  Or something else?  I've been
> > told that there is no SPI driver for 4xx.  If you have done this on 4xx
> > then I'm very interested.
> 
> The 4xx SPI driver is (finally) queued for 2.6.32. So you either need to 
> manually apply it now or wait a while.
> 
> Best regards,
> Stefan
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: need help getting SPI controller working on 405EX

[Stefan Roese]

On Tuesday 11 August 2009 17:59:26 Nathan French wrote:
> This is good news.  Can you point me towards the patch for that?

Sure. Latest version is: "[PATCH v8] spi: Add PPC4xx SPI driver":

http://article.gmane.org/gmane.linux.ports.ppc64.devel/57940

Best regards,
Stefan