R: [PATCH v3 1/2] net: mdio: add ipq8064 mdio driver
From: ansuelsmth
Date: Thu Feb 20 2020 - 19:49:26 EST
> On Fri, Feb 21, 2020 at 12:26:21AM +0100, Ansuel Smith wrote:
> > Currently ipq806x soc use generi bitbang driver to
> > comunicate with the gmac ethernet interface.
> > Add a dedicated driver created by chunkeey to fix this.
> >
> > Christian Lamparter <chunkeey@xxxxxxxxx>
> > Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
> > ---
> > drivers/net/phy/Kconfig | 8 ++
> > drivers/net/phy/Makefile | 1 +
> > drivers/net/phy/mdio-ipq8064.c | 163
> +++++++++++++++++++++++++++++++++
> > 3 files changed, 172 insertions(+)
> > create mode 100644 drivers/net/phy/mdio-ipq8064.c
> >
> > diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> > index 9dabe03a668c..ec2a5493a7e8 100644
> > --- a/drivers/net/phy/Kconfig
> > +++ b/drivers/net/phy/Kconfig
> > @@ -157,6 +157,14 @@ config MDIO_I2C
> >
> > This is library mode.
> >
> > +config MDIO_IPQ8064
> > + tristate "Qualcomm IPQ8064 MDIO interface support"
> > + depends on HAS_IOMEM && OF_MDIO
> > + depends on MFD_SYSCON
> > + help
> > + This driver supports the MDIO interface found in the network
> > + interface units of the IPQ8064 SoC
> > +
> > config MDIO_MOXART
> > tristate "MOXA ART MDIO interface support"
> > depends on ARCH_MOXART || COMPILE_TEST
> > diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
> > index fe5badf13b65..8f02bd2089f3 100644
> > --- 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-$(CONFIG_MDIO_IPQ8064) += mdio-ipq8064.o
> > obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o
> > obj-$(CONFIG_MDIO_MSCC_MIIM) += mdio-mscc-miim.o
> > obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o
> > diff --git a/drivers/net/phy/mdio-ipq8064.c b/drivers/net/phy/mdio-
> ipq8064.c
> > new file mode 100644
> > index 000000000000..e974a6f5d5ef
> > --- /dev/null
> > +++ b/drivers/net/phy/mdio-ipq8064.c
> > @@ -0,0 +1,163 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +//
> > +// Qualcomm IPQ8064 MDIO interface driver
> > +//
> > +// Copyright (C) 2019 Christian Lamparter <chunkeey@xxxxxxxxx>
> > +
> > +#include <linux/delay.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/regmap.h>
> > +#include <linux/of_mdio.h>
> > +#include <linux/phy.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/mfd/syscon.h>
> > +
> > +/* MII address register definitions */
> > +#define MII_ADDR_REG_ADDR 0x10
> > +#define MII_BUSY BIT(0)
> > +#define MII_WRITE BIT(1)
> > +#define MII_CLKRANGE_60_100M (0 << 2)
> > +#define MII_CLKRANGE_100_150M (1 << 2)
> > +#define MII_CLKRANGE_20_35M (2 << 2)
> > +#define MII_CLKRANGE_35_60M (3 << 2)
> > +#define MII_CLKRANGE_150_250M (4 << 2)
> > +#define MII_CLKRANGE_250_300M (5 << 2)
> > +#define MII_CLKRANGE_MASK GENMASK(4, 2)
> > +#define MII_REG_SHIFT 6
> > +#define MII_REG_MASK GENMASK(10, 6)
> > +#define MII_ADDR_SHIFT 11
> > +#define MII_ADDR_MASK GENMASK(15, 11)
> > +
> > +#define MII_DATA_REG_ADDR 0x14
> > +
> > +#define MII_MDIO_DELAY (1000)
>
> Maybe name this MII_MDIO_DELAY_USEC to show that it is in
> microseconds?
>
> > +#define MII_MDIO_RETRY (10)
>
> Maybe name this MII_MDIO_RETRY_MSEC to show that it is in
> milliseconds?
>
> > +
> > +struct ipq8064_mdio {
> > + struct regmap *base; /* NSS_GMAC0_BASE */
> > +};
> > +
> > +static int
> > +ipq8064_mdio_wait_busy(struct ipq8064_mdio *priv)
> > +{
> > + u32 busy;
> > +
> > + return regmap_read_poll_timeout(priv->base,
> MII_ADDR_REG_ADDR, busy,
> > + !(busy & MII_BUSY), MII_MDIO_DELAY,
> > + MII_MDIO_RETRY * USEC_PER_MSEC);
>
> Thanks.
>
> > +}
> > +
> > +static int
> > +ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset)
> > +{
> > + struct ipq8064_mdio *priv = bus->priv;
> > + u32 miiaddr = MII_BUSY | MII_CLKRANGE_250_300M;
> > + u32 ret_val;
> > + int err;
> > +
> > + /* Reject clause 45 */
> > + if (reg_offset & MII_ADDR_C45)
> > + return -EOPNOTSUPP;
>
> Thanks.
>
> > +
> > + miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
> > + ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
> > +
> > + regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
> > + usleep_range(10, 20);
> > +
> > + err = ipq8064_mdio_wait_busy(priv);
> > + if (err)
> > + return err;
> > +
> > + regmap_read(priv->base, MII_DATA_REG_ADDR, &ret_val);
> > + return (int)ret_val;
> > +}
> > +
> > +static int
> > +ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset,
> u16 data)
> > +{
> > + struct ipq8064_mdio *priv = bus->priv;
> > + u32 miiaddr = MII_WRITE | MII_BUSY | MII_CLKRANGE_250_300M;
> > +
> > + /* Reject clause 45 */
> > + if (reg_offset & MII_ADDR_C45)
> > + return -EOPNOTSUPP;
>
> Thanks.
>
> > +
> > + regmap_write(priv->base, MII_DATA_REG_ADDR, data);
> > +
> > + miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
> > + ((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
> > +
> > + regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
> > + usleep_range(10, 20);
> > +
> > + return ipq8064_mdio_wait_busy(priv);
> > +}
> > +
> > +static int
> > +ipq8064_mdio_probe(struct platform_device *pdev)
> > +{
> > + struct device_node *np = pdev->dev.of_node;
> > + struct ipq8064_mdio *priv;
> > + struct mii_bus *bus;
> > + int ret;
> > +
> > + bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
> > + if (!bus)
> > + return -ENOMEM;
> > +
> > + bus->name = "ipq8064_mdio_bus";
> > + bus->read = ipq8064_mdio_read;
> > + bus->write = ipq8064_mdio_write;
> > + snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev-
> >dev));
> > + bus->parent = &pdev->dev;
> > +
> > + priv = bus->priv;
> > + priv->base = syscon_node_to_regmap(np);
> > + if (IS_ERR_OR_NULL(priv->base)) {
> > + priv->base = syscon_regmap_lookup_by_phandle(np,
> "master");
> > + if (IS_ERR_OR_NULL(priv->base)) {
> > + dev_err(&pdev->dev, "master phandle not
> found\n");
> > + return -EINVAL;
> > + }
> > + }
>
> I'm curious why you've kept this as-is given my comments?
>
> If you don't agree with them, it would be helpful to reply to the
> review email giving the reasons why.
>
> Thanks.
>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down
> 622kbps up
> According to speedtest.net: 11.9Mbps down 500kbps up
I hope it's not a problem if I answer here.
I read your command and now I understand what you mean. Since they both
never return NULL the IS_ERR_OR_NULL is wrong and only IS_ERR should be
used. Correct me if I'm wrong.
About the error propagation, should I return the
syscon_regmap_lookup_by_phandle
error or I can keep the EINVAL error?