mmc-spi update
Quoted 6 lines · Jan Nikitenko
Quoted 4 lines · David Brownell
Just for the record, my plan is to post updates against 2.6.22-rc1 (with the MMC stack reorg, new CRC, etc) and then start splitting this up into more mergeable chunks once it all works again on some hardware I have in hand.
Revised plan: it'll probably be against RC4, and that will include some of how I think that code splitting should work.
Quoted 4 lines
Quoted 2 lines
It sure seems like this _ought_ to be nearly mergeable by now, at least in terms of the "it works" metric. In terms of factoring
so now it works also with your hw?
I had to change f_min from 125 KHz to 400 KHz, since the minimum that my hardware supports is 138 KHz. At least without some nasty updates to the controller driver, forcing it in and out of a global divide-by-32 mode based on what device it's talking to. :(
Turns out the main reason for enumerating with a low frequency is because MMC (or SD) cards would start in BUSMODE_OPENDRAIN, which has speed limits not unlike I2C. But since SPI doesn't use that mode, there seems to be no need to be that low. The only solid constraint I could find is that lowspeed SDIO cards may not work with speeds over 400 KHz.
- Dave
Quoted 8 lines
Jan
Quoted 5 lines
the code, it's too monolithic ... but I think that probably helped get us this far, since circulating a bunch of mmc core patches along with a driver-in-development would have been painful.
- Dave
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