Author: wmb Date: Tue Aug 2 05:55:57 2011 New Revision: 2400 URL: http://tracker.coreboot.org/trac/openfirmware/changeset/2400
Log: OLPC XO-1.75 - trac #11089 - changed the SSP SPI driver to avoid glitches that confuse the SPI FLASH chip.
Modified: cpu/arm/mmp2/sspspi.fth
Modified: cpu/arm/mmp2/sspspi.fth ============================================================================== --- cpu/arm/mmp2/sspspi.fth Tue Aug 2 05:31:12 2011 (r2399) +++ cpu/arm/mmp2/sspspi.fth Tue Aug 2 05:55:57 2011 (r2400) @@ -12,8 +12,11 @@ : ssp-sssr ( -- adr ) ssp-base 2 la+ ; : ssp-ssdr ( -- adr ) ssp-base 4 la+ ;
- : ssp-spi-start ( -- ) + \ Avoid reinitializing the device after the first time, as that + \ seems to cause glitches that confuse the SPI FLASH chip + ssp-sscr1 io@ 0= if exit then + h# 07 ssp-sscr0 io! 0 ssp-sscr1 io! h# 87 ssp-sscr0 io! @@ -127,16 +130,8 @@ : ssp-spi-out ( b -- ) ssp-spi-out-in drop ; : ssp-spi-in ( -- b ) 0 ssp-spi-out-in ;
-: safe-spi-start - ssp-spi-start - \ The following clears out some glitches so the chip will respond - \ to the ab-id command. - 0 spi-cmd spi-cs-off - 0 spi-cmd spi-cs-off -; - : use-ssp-spi ( -- ) - ['] safe-spi-start to spi-start + ['] ssp-spi-start to spi-start ['] ssp-spi-in to spi-in ['] ssp-spi-out to spi-out ['] ssp-spi-cs-on to spi-cs-on