Re: [PATCH 1/1] netdev/phy: add MDIO bus multiplexer driven by a regmap
From: Andrew Lunn <andrew@lunn.ch>
Date: 2019-01-30 15:33:39
On Wed, Jan 30, 2019 at 11:22:00AM +0000, Pankaj Bansal wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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