Hi Philipp, On Wednesday 04 June 2014 18:45:28 Philipp Zabel wrote: > Am Mittwoch, den 04.06.2014, 17:44 +0200 schrieb Laurent Pinchart: > > On Tuesday 03 June 2014 11:35:55 Philipp Zabel wrote: > > > This switches all register accesses to use regmap. It allows to > > > use the regmap cache, tracing, and debug register dump facilities, > > > and removes the need to open code read-modify-writes. > > > > > > Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > > > > This looks good to me, but I have two small questions: > > > > - How does regmap handle endianness ? It seems to hardcode a big endian > > byte order, which is fortunately what we need here. > > We could set regmap_config->val_format_endian = REGMAP_ENDIAN_BIG. > This defaults to big endian unless the regmap_bus says otherwise > (regmap-i2c doesn't). OK, thank you for the information. > > I suppose you've successfully tested this patch :-) > > Yes. > > > - How does regmap handle the register cache ? Will it try to populate it > > when initialized, or will it only read registers on demand due to a read > > or an update bits operation ? > > That depends on the cache implementation. regcache-rbtree has a > cache_present bitmap per node. As long as the corresponding bit is not > set, regcache_read will return -ENOENT and regmap_read will then do an > actual register read (and store the result in the cache). > > regcache-flat doesn't have this at all, so it would be necessary to > provide initial register values in the driver or explicitly read back > from the hardware during initialization. This is also be possible with > the rbtree cache. That sounds good to me. I'll apply your rebased version. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
