> --- a/drivers/net/phy/Makefile > +++ b/drivers/net/phy/Makefile > @@ -36,6 +36,7 @@ obj-$(CONFIG_MDIO_CAVIUM) += mdio-cavium.o > obj-$(CONFIG_MDIO_GPIO) += mdio-gpio.o > obj-$(CONFIG_MDIO_HISI_FEMAC) += mdio-hisi-femac.o > obj-$(CONFIG_MDIO_I2C) += mdio-i2c.o > +obj-$(CONFIG_MDIO_IPQ40XX) += mdio-ipq40xx.o > obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o > obj-$(CONFIG_MDIO_MSCC_MIIM) += mdio-mscc-miim.o Hi Robert That looks odd. What happened to the obj-$(CONFIG_MDIO_IPQ8064) += mdio-ipq8064.o > obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o > diff --git a/drivers/net/phy/mdio-ipq40xx.c b/drivers/net/phy/mdio-ipq40xx.c > new file mode 100644 > index 000000000000..8068f1e6a077 > --- /dev/null > +++ b/drivers/net/phy/mdio-ipq40xx.c > @@ -0,0 +1,180 @@ > +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause > +/* Copyright (c) 2015, The Linux Foundation. All rights reserved. */ > + > +#include <linux/delay.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/io.h> > +#include <linux/of_address.h> > +#include <linux/of_mdio.h> > +#include <linux/phy.h> > +#include <linux/platform_device.h> > + > +#define MDIO_CTRL_0_REG 0x40 > +#define MDIO_CTRL_1_REG 0x44 > +#define MDIO_CTRL_2_REG 0x48 > +#define MDIO_CTRL_3_REG 0x4c > +#define MDIO_CTRL_4_REG 0x50 Can we have better names than as. It seems like 3 is read data, 2 is write data, etc. > +#define MDIO_CTRL_4_ACCESS_BUSY BIT(16) > +#define MDIO_CTRL_4_ACCESS_START BIT(8) > +#define MDIO_CTRL_4_ACCESS_CODE_READ 0 > +#define MDIO_CTRL_4_ACCESS_CODE_WRITE 1 > +#define CTRL_0_REG_DEFAULT_VALUE 0x150FF No magic numbers please. Try to explain what each of these bits do. I'm guessing they are clock speed, preamble enable, maybe C22/C45? > + > +#define IPQ40XX_MDIO_RETRY 1000 > +#define IPQ40XX_MDIO_DELAY 10 > + > +struct ipq40xx_mdio_data { > + struct mii_bus *mii_bus; > + void __iomem *membase; > + struct device *dev; > +}; > + > +static int ipq40xx_mdio_wait_busy(struct ipq40xx_mdio_data *am) > +{ > + int i; > + > + for (i = 0; i < IPQ40XX_MDIO_RETRY; i++) { > + unsigned int busy; > + > + busy = readl(am->membase + MDIO_CTRL_4_REG) & > + MDIO_CTRL_4_ACCESS_BUSY; > + if (!busy) > + return 0; > + > + /* BUSY might take to be cleard by 15~20 times of loop */ > + udelay(IPQ40XX_MDIO_DELAY); > + } > + > + dev_err(am->dev, "%s: MDIO operation timed out\n", am->mii_bus->name); dev_err() should give you enough to identify the device. No need to print am->mii_bus->name as well. > + > + return -ETIMEDOUT; > +} > + > +static int ipq40xx_mdio_read(struct mii_bus *bus, int mii_id, int regnum) > +{ > + struct ipq40xx_mdio_data *am = bus->priv; > + int value = 0; > + unsigned int cmd = 0; > + > + lockdep_assert_held(&bus->mdio_lock); Do you think the core is broken? Please check if the request is for a C45 read, and return -EOPNOTSUPP if so. > + > + if (ipq40xx_mdio_wait_busy(am)) > + return -ETIMEDOUT; > + > + /* issue the phy address and reg */ > + writel((mii_id << 8) | regnum, am->membase + MDIO_CTRL_1_REG); > + > + cmd = MDIO_CTRL_4_ACCESS_START | MDIO_CTRL_4_ACCESS_CODE_READ; > + > + /* issue read command */ > + writel(cmd, am->membase + MDIO_CTRL_4_REG); > + > + /* Wait read complete */ > + if (ipq40xx_mdio_wait_busy(am)) > + return -ETIMEDOUT; > + > + /* Read data */ > + value = readl(am->membase + MDIO_CTRL_3_REG); > + > + return value; > +} > + > +static int ipq40xx_mdio_write(struct mii_bus *bus, int mii_id, int regnum, > + u16 value) > +{ > + struct ipq40xx_mdio_data *am = bus->priv; > + unsigned int cmd = 0; > + > + lockdep_assert_held(&bus->mdio_lock); > + > + if (ipq40xx_mdio_wait_busy(am)) > + return -ETIMEDOUT; > + > + /* issue the phy address and reg */ > + writel((mii_id << 8) | regnum, am->membase + MDIO_CTRL_1_REG); > + > + /* issue write data */ > + writel(value, am->membase + MDIO_CTRL_2_REG); > + > + cmd = MDIO_CTRL_4_ACCESS_START | MDIO_CTRL_4_ACCESS_CODE_WRITE; > + /* issue write command */ > + writel(cmd, am->membase + MDIO_CTRL_4_REG); > + > + /* Wait write complete */ > + if (ipq40xx_mdio_wait_busy(am)) > + return -ETIMEDOUT; > + > + return 0; > +} > + > +static int ipq40xx_mdio_probe(struct platform_device *pdev) > +{ > + struct ipq40xx_mdio_data *am; Why the name am? Generally priv is used. I could also understand bus, or even data, but am? Andrew