Re: [PATCH v2] mux: mmio: use reg property when parent device is not a syscon

[Greg Kroah-Hartman]

On Mon, Aug 07, 2023 at 01:26:45PM -0500, Nishanth Menon wrote:
> On 15:12-20230713, Andrew Davis wrote:
> > On 6/5/23 10:41 AM, Andrew Davis wrote:
> > > The DT binding for the reg-mux compatible states it can be used when the
> > > "parent device of mux controller is not syscon device". It also allows
> > > for a reg property. When the reg property is provided, use that to
> > > identify the address space for this mux. If not provided fallback to
> > > using the parent device as a regmap provider.
> > > 
> > > Signed-off-by: Andrew Davis <afd@xxxxxx>
> > > ---
> > 
> > Ping, still needed and applies cleanly on v6.5-rc1.
> > 
> > Andrew
> > 
> > > 
> > > Changes from v1:
> > >   - Flip logic as suggested in v1[0]
> > > 
> > > [0] https://lore.kernel.org/lkml/1c27d9d4-b1cc-c158-90f7-f7e47e02c424@xxxxxx/T/
> > > 
> > >   drivers/mux/mmio.c | 9 ++++++---
> > >   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> 
> Reviewed-by: Nishanth Menon <nm@xxxxxx>
> 
> Greg: looks like you were missed in CC
> 
> Peter/Greg: Any chance of Looking at this? This is a basic corner stone
> for us to clean up much of the mess we have created up in the device
> tree syscon nodes and trying to transition those into simple-bus.
> 
> > > 
> > > diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
> > > index 44a7a0e885b8d..2c9e4df9d6f2c 100644
> > > --- a/drivers/mux/mmio.c
> > > +++ b/drivers/mux/mmio.c
> > > @@ -44,10 +44,13 @@ static int mux_mmio_probe(struct platform_device *pdev)
> > >   	int ret;
> > >   	int i;
> > > -	if (of_device_is_compatible(np, "mmio-mux"))
> > > +	if (of_device_is_compatible(np, "mmio-mux")) {
> > >   		regmap = syscon_node_to_regmap(np->parent);
> > > -	else
> > > -		regmap = dev_get_regmap(dev->parent, NULL) ?: ERR_PTR(-ENODEV);
> > > +	} else {
> > > +		regmap = device_node_to_regmap(np);
> > > +		if (IS_ERR(regmap))
> > > +			regmap = dev_get_regmap(dev->parent, NULL) ?: ERR_PTR(-ENODEV);
> > > +	}
> > >   	if (IS_ERR(regmap)) {
> > >   		ret = PTR_ERR(regmap);
> > >   		dev_err(dev, "failed to get regmap: %d\n", ret);

I'm not the maintainer here, it's up to Peter.