*** PROBABLY SPAM *** No Clock on SPI
laurent.pinchart at tbox.biz
Wed Aug 16 23:22:36 EST 2006
> 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?
I'm working on an SPI driver for the MPC8248. I'll try to send a patch in a
> 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.
Make sure you programmed the SPMODE register correctly.
> How I have to allocate the Memory for the BD´s and the buffer for the BD´s?
The buffer descriptors should be allocated from CPM DPRAM using cpm_dpalloc().
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_SPI
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 file.
*(u16 *)(&immap->im_dprambase[PROFF_SPI_BASE]) = PROFF_SPI;
in your driver code, and set the SPI pram resource to
.name = "pram",
.start = 0x00c0,
.end = 0x00ff,
.flags = IORESOURCE_MEM,
> 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.
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