On Thu, Jun 3, 2021 at 1:01 PM Sander Vanheule <sander@xxxxxxxxxxxxx> wrote: > > The RTL8231 is implemented as an MDIO device, and provides a regmap > interface for register access by the core and child devices. > > The chip can also be a device on an SMI bus, an I2C-like bus by Realtek. > Since kernel support for SMI is limited, and no real-world SMI > implementations have been encountered for this device, this is currently > unimplemented. The use of the regmap interface should make any future > support relatively straightforward. > > After reset, all pins are muxed to GPIO inputs before the pin drivers > are enabled. This is done to prevent accidental system resets, when a > pin is connected to the parent SoC's reset line. > > To provide different read and write semantics for the GPIO data > registers, a secondary virtual register range is used to enable separate > cacheing properties of pin input and output values. caching ... > +static int rtl8231_reg_read(void *context, unsigned int reg, unsigned int *val) > +{ > + struct mdio_device *mdio_dev = context; > + int ret; > + > + ret = mdiobus_read(mdio_dev->bus, mdio_dev->addr, RTL8231_REAL_REG(reg)); > + > + if (ret < 0) > + return ret; > + > + *val = ret & 0xffff; > + > + return 0; > +} > + > +static int rtl8231_reg_write(void *context, unsigned int reg, unsigned int val) > +{ > + struct mdio_device *mdio_dev = context; > + > + return mdiobus_write(mdio_dev->bus, mdio_dev->addr, RTL8231_REAL_REG(reg), val); > +} Hmm... Maybe we can amend regmap-mdio to avoid duplication of the above? Something like xlate in gpio-regmap or so? ... > + mdiodev->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); Missed if (IS_ERR(mdiodev->reset_gpio)) return PTR_ERR(mdiodev->reset_gpio); -- With Best Regards, Andy Shevchenko