PERFORCE change 112700 for review
Warner Losh
imp at FreeBSD.org
Tue Jan 9 22:56:56 PST 2007
http://perforce.freebsd.org/chv.cgi?CH=112700
Change 112700 by imp at imp_lighthouse on 2007/01/10 06:56:33
MF FreeBSD-tsc-6: slow down spi bus enough to make the dataflash
parts reliable on read. MCK / 2 is too fast. I think MCK / 4
would work too, but MCK / 20 was rock solid.
I think this works in the boot loader because we're running with
the caches off, slowing things down, but I am actually a bit
baffled. Maybe I just have a bad board...
Affected files ...
.. //depot/projects/arm/src/sys/arm/at91/at91_spi.c#16 edit
Differences ...
==== //depot/projects/arm/src/sys/arm/at91/at91_spi.c#16 (text+ko) ====
@@ -115,7 +115,7 @@
WR4(sc, SPI_MR, (0xf << 24) | SPI_MR_MSTR | SPI_MR_MODFDIS |
(0xE << 16));
- WR4(sc, SPI_CSR0, SPI_CSR_CPOL | (4 << 16) | (2 << 8));
+ WR4(sc, SPI_CSR0, SPI_CSR_CPOL | (4 << 16) | (20 << 8));
WR4(sc, SPI_CR, SPI_CR_SPIEN);
WR4(sc, PDC_PTCR, PDC_PTCR_TXTDIS);
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