Messages in this thread | | | Date | Wed, 04 Apr 2012 17:15:42 -0600 | From | Stephen Warren <> | Subject | Re: [PATCH 4/6] regmap: add MMIO bus support |
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On 04/04/2012 04:59 PM, Mark Brown wrote: > On Wed, Apr 04, 2012 at 03:48:31PM -0600, Stephen Warren wrote: >> From: Stephen Warren <swarren@nvidia.com> >> >> This is a basic memory-mapped-IO bus for regmap. It has the following >> features and limitations: > > I applied these up to here but it was painful as patch 2 didn't apply > cleanly to -rc1 and git am couldn't find the blobs to use for > resolution. Please check things worked out OK but I'm pretty sure they > did.
The result of merging your topic/mmio and for-next branches is the same as my local copy of patch 4 I sent, modulo that my local copy still has regmap_open_file(), but that's not related.
So yes, I think the patches applied fine.
>> * Registers themselves may be 8, 16, 32, or 64-bit. 64-bit is only >> supported on 64-bit platforms. >> * Register offsets are limited to precisely 32-bit. >> * IO is performed using readl/writel, with no provision for using the >> __raw_readl or readl_relaxed variants. > > Also limited native endian register I/O. It would have been much better > to fix this in the core - please consider producing followup patches to > push the code there, though it's far from essential.
I assume the solution here is to:
* Always use __raw_readl/__raw_writel in regmap-mmio.c so that there's never any endianness conversion, and don't use the endianness conversion macros when reading/writing the work buffer. * Implement alternative formatters that format in LE instead of BE * Add a field to regmap_config indicating which endianness the data should be in, and use this flag to select the LE/BE formatters.
Does that sound about right?
>> +static int regmap_mmio_gather_write(void *context, >> + const void *reg, size_t reg_size, >> + const void *val, size_t val_size) >> +{ >> + struct regmap_mmio_context *ctx = context; >> + u32 offset; >> + >> + if (reg_size != 4) >> + return -EIO; > > Given that you constrain on registration too this should be BUG_ON(), > we're seriously confused if we're specifying a different register size > here and -EIO is going to be a bit obscure.
I wondered about that. I would have been quite happy to repost with that change. Do you want an incremental patch?
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