Messages in this thread | | | Date | Fri, 24 Sep 2010 11:57:40 +0400 | From | Anton Vorontsov <> | Subject | Re: [PATCH] spi_mpc8xxx: issue with using definition of pram in Device Tree |
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Hello,
On Fri, Sep 24, 2010 at 09:20:27AM +0200, LEROY Christophe wrote: > The issue is that cpm_muram_alloc_fixed() allocates memory from the > general purpose muram area (from 0x0 to 0x1bff). > Here we need to return a pointer to the parameter RAM, which is > located somewhere starting at 0x1c00. It is not a dynamic allocation > that is required here but only to point on the correct location in > the parameter RAM. > > For the CPM2, I don't know. I'm working with a MPC866. > > Attached is a previous discussion on the subject where I explain a > bit more in details the issue.
The patch looks OK, I think.
Doesn't explain why that worked on MPC8272 (CPM2) and MPC8560 (also CPM2) machines though. But here's my guess (I no longer have these boards to test it):
On 8272 I used this node:
+ spi@4c0 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "fsl,cpm2-spi", "fsl,spi"; + reg = <0x11a80 0x40 0x89fc 0x2>;
On that SOC there are two muram data regions 0x0..0x2000 and 0x9000..0x9100. Note that we actually don't want "data" regions, and the only reason why that worked is that sysdev/cpm_common.c maps muram(0)..muram(max).
Thanks,
-- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2
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