Re: Page select register restrictions in regmap core

[Guenter Roeck]

On 6/18/24 10:45, Mark Brown wrote:
> On Tue, Jun 18, 2024 at 09:14:56AM -0700, Guenter Roeck wrote:
>
> > Anyway, this may be all irrelevant in respect to regmap support.
> > It turns out that at least some i801 controllers don't work with the
> > access mechanism used by regmap, or maybe the spd5118 chips don't support
> > I2C_FUNC_SMBUS_I2C_BLOCK. I already found that those chips don't support
> > auto-incrementing the register address and actually reset the address on byte
> > reads (i.e., subsequent calls to i2c_smbus_read_byte() always return the data
> > from the first register). Since regmap doesn't have a means for me to say
> > "don't use I2C_FUNC_SMBUS_I2C_BLOCK even if the controller supports it",
> > I may have to drop regmap support entirely anyway. That would be annoying,
> > but right now I have no idea how to work around that problem.
>
> You can set the use_single_read and use_single_write flags in the config
> to ensure registers are accessed one at a time, that restriction is
> moderately common.

I'll give it a try.

Thanks!

Guenter