No Clock on SPI

No Clock on SPI

[GSM909]

Hi

I´m writing a Driver for SPI. That is not working now.
I have a MPC8260 using Linux 2.6.14 (rheap patch).

Did someone else write a driver for SPI on this µC or an other driver? So I can see what i did wrong?

My SPCOM[STR] flag isn´t cleared automatically after one clock cycle.
What here going wrong ? ( I know this register is write only)
There is also no Clock on my SPICLK.

How I have to allocate the Memory for the BD´s and the buffer for the BD´s?

Is there something special when I allocate Memory for my Parameter Ram?

Is something wrong with the 2.6 Kernel so i have to use the 2.4 Kernel ?

I hope somebody could help. Thx

Regards
Fred

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Re: *** PROBABLY SPAM *** No Clock on SPI

[Laurent Pinchart]

Hi Fred,

> I=C2=B4m writing a Driver for SPI. That is not working now.
> I have a MPC8260 using Linux 2.6.14 (rheap patch).
>
> Did someone else write a driver for SPI on this =C2=B5C or an other drive=
r? So I
> can see what i did wrong?

I'm working on an SPI driver for the MPC8248. I'll try to send a patch in a=
=20
few days.

> My SPCOM[STR] flag isn=C2=B4t cleared automatically after one clock cycle.
> What here going wrong ? ( I know this register is write only)
> There is also no Clock on my SPICLK.

Make sure you programmed the SPMODE register correctly.

> How I have to allocate the Memory for the BD=C2=B4s and the buffer for th=
e BD=C2=B4s?

The buffer descriptors should be allocated from CPM DPRAM using cpm_dpalloc=
().=20
The buffers can be allocated from any DMA-able memory (all system memory).

> Is there something special when I allocate Memory for my Parameter Ram?

You don't need to allocate memory for the parameter RAM. I declared PROFF_S=
PI=20
equal to 192 (I2C parameter RAM is at 128) in include/asm-ppc/cpm2.h:

#define PROFF_SMC1      (0)
#define PROFF_SMC2      (64)
#define PROFF_I2C       (128)
#define PROFF_SPI       (192)

Don't forget to set CPM_DATAONLY_BASE to 256 instead of 128 in the same fil=
e.

Then, set

*(u16 *)(&immap->im_dprambase[PROFF_SPI_BASE]) =3D PROFF_SPI;

in your driver code, and set the SPI pram resource to

=2Ename   =3D "pram",
=2Estart  =3D 0x00c0,
=2Eend    =3D 0x00ff,
=2Eflags  =3D IORESOURCE_MEM,

in arch/ppc/syslib/pq2_devices.c

> Is something wrong with the 2.6 Kernel so i have to use the 2.4 Kernel ?

You should not use 2.4. 2.6 is the way to go.

Laurent Pinchart