Re: [PATCH 3/9] powerpc/ppc32: Update mpc52xx_psc structure with B revision changes
From: Raquel Velasco and Bill Buck <hidden>
Date: 2007-05-15 10:59:40
Sylvain, thanks. http://bbrv.blogspot.com/2007/05/not-waiting-for-world-to-change-ii.html Read through the post. Your effort is being applied to good use. R&B On May 14, 2007, at 12:27 AM, Sylvain Munaut wrote:
Matt Sealey wrote:quoted
Would a note next to these new fields be worth it? "5200B only" or "reserved on 5200" or even create a new PSC structure for the old processor and recast it in drivers that really want to support both revisions of the CPU?A comment next to them yes, that looks a good idea. A new structure certainly not.quoted
Real nitpick: Setting the CCR on the MPC5200 (not B) now means you need to left shift your required CCR values by 16 bits before applying them into the field for the desired effect. If you were being lazy and just wanted to set some low-order bits in the CCR on the 5200, with the old structure that's fine. With the new structure, it will be writing into previously reserved space on the 5200. The 5200B might work fine, unless it's a driver someone missed, and is programming a value that should be in the upper 16 bits of the new CCR, in which case now you have to left shift by 16 bits.. :)I know about the ccr that's annoying. I guess I could make ccr a union and have it contains ccr16 and ccr32. Note that old driver will still work ... then most likely do out_be16(&psc->ccr, ...) and the &psc->ccr address didn't change. They will just have a warning because ccr is a u32 so &psc->ccr is a u32* and they give it to out_be16 ... Sylvain _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Raquel and Bill http://bbrv.blogspot.com