[En-Nut-Discussion] SAM7X SPI

[Tim DeBaillie]

On Wed, 6 Sep 2006, Harald Kipp wrote:

> Have a look to the arch/arm/dev/spimmc_at91.c.
>
> Not perfect, but it shows how to use the SPI interface for the
> MMC/SD Card interface.


from the spimmc_at91.c file:

/* SPI enable and reset. */
outr(SPI0_CR, SPI_SPIEN | SPI_SWRST);
outr(SPI0_CR, SPI_SPIEN);

/* Set SPI to master mode, fixed peripheral at CS1, fault detection 
disabled. */
outr(SPI0_MR, (1 << SPI_PCS_LSB) | SPI_MODFDIS | SPI_MSTR);

/* Data changes during clock low and will be sampled on rising edges. */
outr(SPI0_CSR1, (3 << SPI_SCBR_LSB) | SPI_CPOL);

~~~~~~~~~

Why would you enable and reset the SPI, then enable it again, then setup 
the mode register, then setup the chip select register?

Should I not setup the mode and chip select registers before enabling the 
SPI?

Does anyone have working code that this driver was used in?  I would like 
to see how you interface with the driver.

Thanks,

Tim

-- 
Tim DeBaillie			812-476-2721 x102
Ciholas Technologies		812-476-2881
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