Chipselect in SPI binding with mpc5200-psc-spi

[Henk Stegeman]

It now works, in the dts

interrupt-controller = < &gpt6 >;     // Use GPT6 as

should have been

interrupt-parent = < &gpt6 >;     // Use GPT6 as

On Tue, Jul 7, 2009 at 5:57 PM, Grant Likely<grant.likely at secretlab.ca> wrote:
> On Tue, Jul 7, 2009 at 8:31 AM, Henk Stegeman<henk.stegeman at gmail.com> wrote:
>> I tried to make use of the irq-controller mode of the GPT as
>> suggested, however I'm not getting the IRQ.
>> Does anyone have an idea what I could be missing? (I've been testing
>> with 2.6.30).
>
> Make sure the 5200 general purpose timer driver is compiled in (not a module).
>
>>
>>
>> The driver reports from it's probe:
>> [    1.502853] spi_master spi32766.0 Unable to get sample IRQ from of
>>
>> My driver has:
>>        pdata->sample_irq = irq_of_parse_and_map(np, 0);
>>        if (pdata->sample_irq == NO_IRQ) {
>>                ret = pdata->sample_irq;
>>                dev_err(dev, "Unable to get sample IRQ from of\n");
>>                ..
>>                }
>>
>>
>> My dts has:
>>        gpt6: timer at 660 {       // General Purpose Timer GPT6 in GPIO mode for
>> SMC4000IO sample irq.
>>                interrupt-controller;
>>                #interrupt-cells = <1>;
>>                compatible = "fsl,mpc5200b-gpt","fsl,mpc5200-gpt";
>>                reg = <0x660 0x10>;
>>                interrupts = <1 15 0>;
>>                interrupt-parent = <&mpc5200_pic>;
>>        };
>>
>>
>>        io-controller at 0 {
>>                compatible = "microkey,smc4000io";
>>                linux,modalias = "of_smc4000io";
>>                spi-max-frequency = <800000>;
>>                spi-cpha;
>>                reg = <0>;
>>                word-delay-us = <30>;
>>                interrupt-controller = <&gpt6>; // Use GPT6 as the IRQ controller
>>                interrupts = <2>; // And make it edge falling
>>        };
>>
>>
>> Thanks in advance,
>>
>> Henk.
>>
>> On Fri, Feb 13, 2009 at 5:19 PM, Grant Likely<grant.likely at secretlab.ca> wrote:
>>> On Fri, Feb 13, 2009 at 3:40 AM, Henk Stegeman <henk.stegeman at gmail.com> wrote:
>>>> I'm busy adding support for slave deviced behind mpc52xx-psc-spi.
>>>> One complication I have is that my SPI slave device has an interrupt output
>>>> to the CPU.
>>>> My idea is to add it as a gpios property in the slave device's
>>>> configuration:
>>>>
>>>>         spi at 2400 {        // PSC3 (SPI IF to the IO-controller )
>>>>             device_type = "spi";
>>>>             #address-cells = <1>;
>>>>             #size-cells = <0>;
>>>>             compatible = "fsl,mpc5200-psc-spi","fsl,mpc5200b-psc-spi";
>>>>             cell-index = <2>;
>>>>             reg = <0x2400 0x100>;
>>>>             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>;
>>>>                 // gpios: first is IRQ to cpu
>>>>                 gpios = <&gpt6 0 0>;
>>>>             };
>>>
>>> There is a better way to do this, and driver support for it is
>>> currently merged into Ben Herrenschmidt's -next tree.
>>>
>>> Do this instead:
>>>        io-controller at 0 {
>>>                compatible = "microkey,smc4000io";
>>>                spi-max-frequency = <1000000>;
>>>                reg = <0>;
>>>                interrupt-controller = < &gpt6 >;     // Use GPT6 as
>>> the IRQ controller
>>>                interrupts = < 1 >;    // And make it rising edge.
>>>        };
>>>
>>> Then add these two properties to the GPT node:
>>>
>>>        interrupt-controller;
>>>        #interrupt-cells = <1>;
>>>
>>> Then you can use normal irq_of_parse_and_map() to set up your handler.
>>>
>>>> How should I then register my spi slave driver? My smc4000io_probe function
>>>> gets called correctly by of_spi support but when I register as follows:
>>>>
>>>> static struct spi_driver smc4000io_driver = {
>>>>     .driver = {
>>>>         .name    = "smc4000io",
>>>>         .bus    = &spi_bus_type,
>>>>         .owner    = THIS_MODULE,
>>>>     },
>>>>     .probe        = smc4000io_probe,
>>>>     .remove        = __devexit_p(smc4000io_remove),
>>>> };
>>>>
>>>> static int __init smc4000io_init(void)
>>>> {
>>>>     return spi_register_driver(&smc4000io_driver);
>>>> }
>>>>
>>>> static void __exit smc4000io_exit(void)
>>>> {
>>>>     spi_unregister_driver(&smc4000io_driver);
>>>> }
>>>>
>>>> module_init(smc4000io_init);
>>>
>>> Yes, this is right.  The psc_spi driver automatically registers all
>>> spi children that it finds in the device tree onto the SPI bus.
>>> Therefore registering an spi_driver() is the right thing to do.
>>>
>>>> But when I do:
>>>>
>>>> static struct of_platform_driver smc4000_spi_of_driver = {
>>>>     .name = "smc4000io",
>>>>     .match_table = smc4000io_of_match,
>>>>     .probe = smc4000io_of_probe,
>>>>     .remove        = __devexit_p(smc4000io_of_remove),
>>>> };
>>>>
>>>> static int __init smc4000io_init(void)
>>>> {
>>>>     return of_register_platform_driver(&smc4000_spi_of_driver);
>>>> }
>>>> module_init(smc4000io_init);
>>>>
>>>> Then my smc4000io_of_probe function never gets called.
>>>
>>> Correct.  of_platform_driver isn't useful in this case because the
>>> device cannot exist independently of the SPI bus.  Plus an
>>> of_platform_device doesn't provide any information about the SPI bus
>>> itself.
>>>
>>> g.
>>>
>>> --
>>> Grant Likely, B.Sc., P.Eng.
>>> Secret Lab Technologies Ltd.
>>>
>>
>
>
>
> --
> Grant Likely, B.Sc., P.Eng.
> Secret Lab Technologies Ltd.
>