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/):
[nfre...@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: s...@ef600600 {
+ cell-index = <0>;
+ compatible = "ibm,spi-405ex", "ibm,spi";
+ reg = <ef600600 6>;
+ interrupts = <8 4>;
+ interrupt-parent = <&UIC0>;
+ mode = "cpu";
+ };
RGMII0: emac-rg...@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:
[r...@10.2.3.28 /]$ find /proc/device-tree/ | grep spi
/proc/device-tree/plb/opb/s...@ef600600
/proc/device-tree/plb/opb/s...@ef600600/name
/proc/device-tree/plb/opb/s...@ef600600/mode
/proc/device-tree/plb/opb/s...@ef600600/interrupt-parent
/proc/device-tree/plb/opb/s...@ef600600/interrupts
/proc/device-tree/plb/opb/s...@ef600600/reg
/proc/device-tree/plb/opb/s...@ef600600/compatible
/proc/device-tree/plb/opb/s...@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: s...@ef600600 {
cell-index = <0>;
compatible = "ibm,spi-405ex", "ibm,spi";
reg = <ef600600 6>;
interrupts = <8 4>;
interrupt-parent = <&UIC0>;
mode = "cpu";
yourdev...@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
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