Chipselect in SPI binding with mpc5200-psc-spi

Grant Likely grant.likely at secretlab.ca
Thu Oct 30 01:45:30 EST 2008


On Wed, Oct 29, 2008 at 7:43 AM, Henk Stegeman <henk.stegeman at gmail.com> wrote:
> ..
> ..
> In my dts
>
> I have my chipselect defined as follows:
>
>         gpt4: timer at 640 {    // General Purpose Timer GPT4 in GPIO mode for
> SMC4000IO chip select.
>             compatible = "fsl,mpc5200b-gpt-gpio","fsl,mpc5200-gpt-gpio";
>             cell-index = <4>;
>             reg = <0x640 0x10>;
>             interrupts = <1 13 0>;
>             interrupt-parent = <&mpc5200_pic>;
>             gpio-controller;
>             #gpio-cells = <2>;
>         };
>
> I found the gpio in
> # cat /sys/class/gpio/gpiochip215/label
> /soc5200 at f0000000/timer at 640
>
> The spi controller is defined like this:
>
>         spi at 2400 {
>             device_type = "spi";
>             #address-cells = <1>;
>             #size-cells = <0>;
>             compatible = "fsl,mpc5200-psc-spi","fsl,mpc5200b-psc-spi";
>             cell-index = <2>;
>             reg = <2400 100>;
>             interrupts = <2 3 0>;
>             interrupt-parent = <&mpc5200_pic>;
>             gpios = <&gpt4 0 0>;
>
>             io-controller at 0 {
>                 compatible = "microkey,smc4000io";
>                 spi-max-frequency = <1000000>;
>                 reg = <0>;
>             };
>         };
>
> At bootup linux (2.6.27) reports:
>
> mpc52xx-psc-spi f0000960.spi: probe called without platform data, no
> (de)activate_cs function will be called.
>
> Is my assumption wrong that the gpios property is the way to map chipselects
> to the spi driver?

Yes, that is the way you should work specify the chip selects, but the
driver hasn't been updated to support it yet.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.



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