Re: [PATCH] regmap: Fix i2c word access when using SMBus access functions

[Guenter Roeck]

On 02/03/2015 03:42 AM, Mark Brown wrote:
> On Mon, Feb 02, 2015 at 06:30:02AM -0800, Guenter Roeck wrote:
> > On 02/02/2015 03:56 AM, Mark Brown wrote:
>
> > > Yes, we really ought to handle _NATIVE too (though the chances of it
> > > being used with I2C are minimal, it's mostly for MMIO).  This also feels
>
> > Well, we do; it is handled similar to the big endian case with the current
> > code. Do you think it should be handled differently ? If yes, how ?
>
> Perhaps it just needs to be more explicit about how it's handling native
> endian?  I didn't spot it.
Thinking about it, we should actually reject requests for _NATIVE. SMBus
16 bit accesses are either little endian or big endian.

> > > like it's something that should be being handled further up the stack in
> > > the serialization code but given that there's direct functions for this
> > > in the smbus code perhaps it's better here.  Or perhaps the smbus
> > > support ought to be transitioned to use the bus interface and set
> > > reg_write() and reg_read() operations now that we can do that, it seems
> > > like a better fit though it might break compatibility with wierd devices.
>
> > I thought about that, but since the smbus functions perform endianness
> > conversion it would mean that I would have to undo that conversion just
> > to have it done again.
>
> No, the whole point is that by doing this you avoid any endianness
> conversions or formatting in the framework at all so you can just use
> the smbus functions to handle the formatting.
Ah, guess I got confused. The SMBus accesses are already using reg_read
and reg_write.

Thanks,
Guenter

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