On Thu, Feb 11, 2021 at 01:28:06AM +0300, Serge Semin wrote: > On Tue, Feb 09, 2021 at 05:13:52PM -0600, Rob Herring wrote: > > On Mon, Feb 08, 2021 at 05:08:05PM +0300, Serge Semin wrote: > > > Synopsys DesignWare Ethernet controllers can be synthesized with > > > General-Purpose IOs support. GPIOs can work either as inputs or as outputs > > > thus belong to the gpi_i and gpo_o ports respectively. The ports width > > > (number of possible inputs/outputs) and the configuration registers layout > > > depend on the IP-core version. For instance, DW GMAC can have from 0 to 4 > > > GPIs and from 0 to 4 GPOs, while DW xGMAC have a wider ports width up to > > > 16 pins of each one. > > > > > > So the DW MAC DT-node can be equipped with "ngpios" property, which can't > > > have a value greater than 32, standard GPIO-related properties like > > > "gpio-controller" and "#gpio-cells", and, if GPIs are supposed to be > > > detected, IRQ-controller related properties. > > > > > > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> > > > --- > > > .../devicetree/bindings/net/snps,dwmac.yaml | 17 +++++++++++++++++ > > > 1 file changed, 17 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml > > > index bdc437b14878..fcca23d3727e 100644 > > > --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml > > > +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml > > > @@ -110,6 +110,23 @@ properties: > > > reset-names: > > > const: stmmaceth > > > > > > + ngpios: > > > + description: > > > + Total number of GPIOs the MAC supports. The property shall include both > > > + the GPI and GPO ports width. > > > + minimum: 1 > > > + maximum: 32 > > > > > Does the driver actually need this? I'd omit it if just to validate > > consumers are in range. > > I can't say for all possible DW MAC IP-cores (I've got manuals for > GMAC and xGMAC only), but at least DW GMAC can't have more than four > GPIs and four GPOs, while XGMACs can be synthesized with up to 16 > each. That's why I've set the upper boundary here as 32. But the > driver uses the ngpios property do determine the total number GPIOs > the core has been synthesized. Th number of GPIs and GPOs will be > auto-detected then (by writing-reading to-from the GPI type field of > the GPIO control register). > > > > > Are GPI and GPO counts independent? If so, this isn't really sufficient. > > Yeap, they are independent. What do you suggest then? Define some > vendor-specific properties like snps,ngpis and snps,ngpos? If so then > they seem more generic than vendor-specific, because the separated > GPI and GPO space isn't an unique feature of the DW MAC GPIOs. Do we > need to create a generic version of such properties then? (That much > more changes then introduced here. We'd need to fix the dt-schema tool > too then.) > > -Sergey Rob, any comment on my questions above? As the kernel is in merge-window now, I just hope this part won't get pushed back in the emails log out of your sight. -Sergey > > > > > Rob
