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From: Grant Likely <grant.likely@secretlab.ca>
To: Henk Stegeman <henk.stegeman@gmail.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: Chipselect in SPI binding with mpc5200-psc-spi
Date: Tue, 7 Jul 2009 09:57:32 -0600	[thread overview]
Message-ID: <fa686aa40907070857m5b604f6fk9bd9301997938b37@mail.gmail.com> (raw)
In-Reply-To: <ae4f76fd0907070731p473fef56wdd410db43f6c4c8a@mail.gmail.com>

On Tue, Jul 7, 2009 at 8:31 AM, Henk Stegeman<henk.stegeman@gmail.com> wrot=
e:
> 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 modul=
e).

>
>
> The driver reports from it's probe:
> [ =A0 =A01.502853] spi_master spi32766.0 Unable to get sample IRQ from of
>
> My driver has:
> =A0 =A0 =A0 =A0pdata->sample_irq =3D irq_of_parse_and_map(np, 0);
> =A0 =A0 =A0 =A0if (pdata->sample_irq =3D=3D NO_IRQ) {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0ret =3D pdata->sample_irq;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0dev_err(dev, "Unable to get sample IRQ fro=
m of\n");
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0..
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0}
>
>
> My dts has:
> =A0 =A0 =A0 =A0gpt6: timer@660 { =A0 =A0 =A0 // General Purpose Timer GPT=
6 in GPIO mode for
> SMC4000IO sample irq.
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-controller;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0#interrupt-cells =3D <1>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible =3D "fsl,mpc5200b-gpt","fsl,mpc=
5200-gpt";
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0x660 0x10>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts =3D <1 15 0>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-parent =3D <&mpc5200_pic>;
> =A0 =A0 =A0 =A0};
>
>
> =A0 =A0 =A0 =A0io-controller@0 {
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible =3D "microkey,smc4000io";
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0linux,modalias =3D "of_smc4000io";
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0spi-max-frequency =3D <800000>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0spi-cpha;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0word-delay-us =3D <30>;
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-controller =3D <&gpt6>; // Use G=
PT6 as the IRQ controller
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts =3D <2>; // And make it edge fa=
lling
> =A0 =A0 =A0 =A0};
>
>
> Thanks in advance,
>
> Henk.
>
> On Fri, Feb 13, 2009 at 5:19 PM, Grant Likely<grant.likely@secretlab.ca> =
wrote:
>> On Fri, Feb 13, 2009 at 3:40 AM, Henk Stegeman <henk.stegeman@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 ou=
tput
>>> to the CPU.
>>> My idea is to add it as a gpios property in the slave device's
>>> configuration:
>>>
>>> =A0 =A0 =A0 =A0 spi@2400 { =A0 =A0 =A0 =A0// PSC3 (SPI IF to the IO-con=
troller )
>>> =A0 =A0 =A0 =A0 =A0 =A0 device_type =3D "spi";
>>> =A0 =A0 =A0 =A0 =A0 =A0 #address-cells =3D <1>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 #size-cells =3D <0>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 compatible =3D "fsl,mpc5200-psc-spi","fsl,mpc52=
00b-psc-spi";
>>> =A0 =A0 =A0 =A0 =A0 =A0 cell-index =3D <2>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 reg =3D <0x2400 0x100>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 interrupts =3D <2 3 0>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 interrupt-parent =3D <&mpc5200_pic>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 gpios =3D <&gpt4 0 0>;
>>>
>>> =A0 =A0 =A0 =A0 =A0 =A0 io-controller@0 {
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 compatible =3D "microkey,smc4000io";
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 spi-max-frequency =3D <1000000>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 reg =3D <0>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 // gpios: first is IRQ to cpu
>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 gpios =3D <&gpt6 0 0>;
>>> =A0 =A0 =A0 =A0 =A0 =A0 };
>>
>> 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:
>> =A0 =A0 =A0 =A0io-controller@0 {
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible =3D "microkey,smc4000io";
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0spi-max-frequency =3D <1000000>;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0>;
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-controller =3D < &gpt6 >; =A0 =
=A0 // Use GPT6 as
>> the IRQ controller
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts =3D < 1 >; =A0 =A0// And make =
it rising edge.
>> =A0 =A0 =A0 =A0};
>>
>> Then add these two properties to the GPT node:
>>
>> =A0 =A0 =A0 =A0interrupt-controller;
>> =A0 =A0 =A0 =A0#interrupt-cells =3D <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 func=
tion
>>> gets called correctly by of_spi support but when I register as follows:
>>>
>>> static struct spi_driver smc4000io_driver =3D {
>>> =A0 =A0 .driver =3D {
>>> =A0 =A0 =A0 =A0 .name =A0 =A0=3D "smc4000io",
>>> =A0 =A0 =A0 =A0 .bus =A0 =A0=3D &spi_bus_type,
>>> =A0 =A0 =A0 =A0 .owner =A0 =A0=3D THIS_MODULE,
>>> =A0 =A0 },
>>> =A0 =A0 .probe =A0 =A0 =A0 =A0=3D smc4000io_probe,
>>> =A0 =A0 .remove =A0 =A0 =A0 =A0=3D __devexit_p(smc4000io_remove),
>>> };
>>>
>>> static int __init smc4000io_init(void)
>>> {
>>> =A0 =A0 return spi_register_driver(&smc4000io_driver);
>>> }
>>>
>>> static void __exit smc4000io_exit(void)
>>> {
>>> =A0 =A0 spi_unregister_driver(&smc4000io_driver);
>>> }
>>>
>>> module_init(smc4000io_init);
>>
>> Yes, this is right. =A0The 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 =3D {
>>> =A0 =A0 .name =3D "smc4000io",
>>> =A0 =A0 .match_table =3D smc4000io_of_match,
>>> =A0 =A0 .probe =3D smc4000io_of_probe,
>>> =A0 =A0 .remove =A0 =A0 =A0 =A0=3D __devexit_p(smc4000io_of_remove),
>>> };
>>>
>>> static int __init smc4000io_init(void)
>>> {
>>> =A0 =A0 return of_register_platform_driver(&smc4000_spi_of_driver);
>>> }
>>> module_init(smc4000io_init);
>>>
>>> Then my smc4000io_of_probe function never gets called.
>>
>> Correct. =A0of_platform_driver isn't useful in this case because the
>> device cannot exist independently of the SPI bus. =A0Plus 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.
>>
>



--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

  reply	other threads:[~2009-07-07 15:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-29 13:43 Chipselect in SPI binding with mpc5200-psc-spi Henk Stegeman
2008-10-29 14:45 ` Grant Likely
2009-02-13 10:40   ` Henk Stegeman
2009-02-13 15:19     ` Grant Likely
2009-02-13 15:52       ` Henk Stegeman
2009-06-15 16:36       ` Kári Davíðsson
2009-06-15 17:31         ` Grant Likely
2009-06-16 10:41           ` Kári Davíðsson
2009-07-07 14:31       ` Henk Stegeman
2009-07-07 15:57         ` Grant Likely [this message]
2009-07-08 13:07           ` Henk Stegeman
  -- strict thread matches above, loose matches on Subject: below --
2009-03-27 21:14 Yann Pelletier

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