On Wed, Jan 30, 2019 at 11:22:00AM +0000, Pankaj Bansal wrote:
> Add support for an MDIO bus multiplexer controlled by a regmap
> device, like an FPGA.
>
> Tested on a NXP LX2160AQDS board which uses the "QIXIS" FPGA
> attached to the i2c bus.
>
> Signed-off-by: Pankaj Bansal <pankaj.ban...@nxp.com>
> ---
> drivers/net/phy/Makefile | 2 +-
> drivers/net/phy/mdio-mux-regmap.c | 170 ++++++++++++++++++++++++++++
> include/linux/mdio-mux.h | 20 ++++
> 3 files changed, 191 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
> index f41b14115fde..16145973a42f 100644
> --- a/drivers/net/phy/Makefile
> +++ b/drivers/net/phy/Makefile
> @@ -25,7 +25,7 @@ obj-$(CONFIG_PHYLIB) += libphy.o
> obj-$(CONFIG_MDIO_BCM_IPROC) += mdio-bcm-iproc.o
> obj-$(CONFIG_MDIO_BCM_UNIMAC) += mdio-bcm-unimac.o
> obj-$(CONFIG_MDIO_BITBANG) += mdio-bitbang.o
> -obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o
> +obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o mdio-mux-regmap.o
Please add a new KCONFIG symbol for it. And think about the
depend/select statement, since you need regmap.
> +/* MDIO multiplexing switch function
> + *
> + * This function is called by the mdio-mux layer when it thinks the mdio bus
> + * multiplexer needs to switch.
> + *
> + * 'current_child' is the current value of the mux register (masked via
> + * s->mask).
> + *
> + * 'desired_child' is the value of the 'reg' property of the target child
> MDIO
> + * node.
> + *
> + * The first time this function is called, current_child == -1.
> + *
> + * If current_child == desired_child, then the mux is already set to the
> + * correct bus.
> + */
Please use kerneldoc formatting for this function documentation.
> +int mdio_mux_regmap_init(struct device *dev,
> + struct device_node *mux_node,
> + void **data)
> +{
> + /* Verify that the 'reg' property of each child MDIO bus does not
> + * set any bits outside of the 'mask'.
> + */
> + for_each_available_child_of_node(mux_node, child) {
> + ret = of_property_read_u32(child, "reg", &val);
> + if (ret) {
> + dev_err(dev, "mdio-mux child node %pOF is missing a
> 'reg' property\n", child);
You can probably remove "mdio-mux child node " making the line < 80,
but still retain the meaning. The child node name should be sufficient
to identify it.
> + of_node_put(child);
> + return -ENODEV;
> + }
> + if (val & ~s->mask) {
> + dev_err(dev, "mdio-mux child node %pOF has a 'reg'
> value with unmasked bits\n", child);
Same here.
Andrew
