Re: [PATCH V3] net/dt: Add support for overriding phy configuration from device tree

From: Grant Likely
Date: Tue Feb 04 2014 - 12:15:33 EST

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On Fri, 17 Jan 2014 17:57:39 -0500, Matthew Garrett <matthew.garrett@xxxxxxxxxx> wrote:
> Some hardware may be broken in interesting and board-specific ways, such
> that various bits of functionality don't work. This patch provides a
> mechanism for overriding mii registers during init based on the contents of
> the device tree data, allowing board-specific fixups without having to
> pollute generic code.
>
> Signed-off-by: Matthew Garrett <matthew.garrett@xxxxxxxxxx>

I've got no problems in principle with the feature. I think it is a good
change. The binding itself feels too verbose to me. As an alternative,
how about the following:

phy-mii-advertise = "10half", "!10full", "!100base4"

So it is a list of features. Prepending a '!' makes it disabled. And we
could add something like "nodefault" to clear the probed settings
entirely before listing the modes we want.

g.

> ---
>
> V3: Break the main function out into some helper functions and store the
> values in some structs.
>
> Documentation/devicetree/bindings/net/phy.txt | 21 +++++++
> drivers/net/phy/phy_device.c | 29 ++++++++-
> drivers/of/of_net.c | 87 +++++++++++++++++++++++++++
> include/linux/of_net.h | 12 ++++
> 4 files changed, 148 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt
> index 7cd18fb..fc50f02 100644
> --- a/Documentation/devicetree/bindings/net/phy.txt
> +++ b/Documentation/devicetree/bindings/net/phy.txt
> @@ -23,6 +23,21 @@ Optional Properties:
> assume clause 22. The compatible list may also contain other
> elements.
>
> +The following properties may be added to either the phy node or the parent
> +ethernet device. If not present, the hardware defaults will be used.
> +
> +- phy-mii-advertise-10half: 1 to advertise half-duplex 10MBit, 0 to disable
> +- phy-mii-advertise-10full: 1 to advertise full-duplex 10MBit, 0 to disable
> +- phy-mii-advertise-100half: 1 to advertise half-duplex 100MBit, 0 to disable
> +- phy-mii-advertise-100full: 1 to advertise full-duplex 100MBit, 0 to disable
> +- phy-mii-advertise-100base4: 1 to advertise 100base4, 0 to disable
> +- phy-mii-advertise-1000half: 1 to advertise half-duplex 1000MBit, 0 to disable
> +- phy-mii-advertise-1000full: 1 to advertise full-duplex 1000MBit, 0 to disable
> +- phy-mii-manual-master: 1 to enable manual master/slave configuration, 0
> + to disable manual master/slave configuration
> +- phy-mii-as-master: 1 to configure phy to act as master, 0 to configure phy
> + to act as slave. Ignored if manual master/slave configuration is not enabled.
> +
> Example:
>
> ethernet-phy@0 {
> @@ -32,4 +47,10 @@ ethernet-phy@0 {
> interrupts = <35 1>;
> reg = <0>;
> device_type = "ethernet-phy";
> + // Disable advertising of full duplex 1000MBit
> + phy-mii-advertise-1000full = <0>;
> + // Force manual phy master/slave configuration
> + phy-mii-manual-master = <1>;
> + // Forcibly configure phy as slave
> + phy-mii-as-master = <0>;
> };
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index d6447b3..91793bc 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -33,6 +33,7 @@
> #include <linux/mii.h>
> #include <linux/ethtool.h>
> #include <linux/phy.h>
> +#include <linux/of_net.h>
>
> #include <asm/io.h>
> #include <asm/irq.h>
> @@ -497,6 +498,28 @@ void phy_disconnect(struct phy_device *phydev)
> }
> EXPORT_SYMBOL(phy_disconnect);
>
> +int phy_override_from_of(struct phy_device *phydev)
> +{
> + int reg, regval;
> + u16 val, mask;
> +
> + /* Check for phy register overrides from OF */
> + for (reg = 0; reg < 16; reg++) {
> + if (!of_get_mii_register(phydev, reg, &val, &mask)) {
> + if (!mask)
> + continue;
> + regval = phy_read(phydev, reg);
> + if (regval < 0)
> + continue;
> + regval &= ~mask;
> + regval |= val;
> + phy_write(phydev, reg, regval);
> + }
> + }
> +
> + return 0;
> +}
> +
> int phy_init_hw(struct phy_device *phydev)
> {
> int ret;
> @@ -508,7 +531,11 @@ int phy_init_hw(struct phy_device *phydev)
> if (ret < 0)
> return ret;
>
> - return phydev->drv->config_init(phydev);
> + ret = phydev->drv->config_init(phydev);
> + if (ret < 0)
> + return ret;
> +
> + return phy_override_from_of(phydev);
> }
>
> /**
> diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c
> index 8f9be2e..75751b7 100644
> --- a/drivers/of/of_net.c
> +++ b/drivers/of/of_net.c
> @@ -93,3 +93,90 @@ const void *of_get_mac_address(struct device_node *np)
> return NULL;
> }
> EXPORT_SYMBOL(of_get_mac_address);
> +
> +struct mii_override {
> + char *prop;
> + u32 supported;
> + u16 value;
> +};
> +
> +static struct mii_override mii_advertise_override[] = {
> + { "phy-mii-advertise-10half", SUPPORTED_10baseT_Half,
> + ADVERTISE_10HALF },
> + { "phy-mii-advertise-10full", SUPPORTED_10baseT_Full,
> + ADVERTISE_10FULL },
> + { "phy-mii-advertise-100half", SUPPORTED_100baseT_Half,
> + ADVERTISE_100HALF },
> + { "phy-mii-advertise-100full", SUPPORTED_100baseT_Full,
> + ADVERTISE_100FULL },
> + { "phy-mii-advertise-100base4", 0, ADVERTISE_100BASE4 },
> + { NULL },
> +};
> +
> +static struct mii_override mii_gigabit_override[] = {
> + { "phy-mii-advertise-1000half", SUPPORTED_1000baseT_Half,
> + ADVERTISE_1000HALF },
> + { "phy-mii-advertise-1000full", SUPPORTED_1000baseT_Full,
> + ADVERTISE_1000FULL },
> + { "phy-mii-as-master", 0, CTL1000_AS_MASTER },
> + { "phy-mii-manual-master", 0, CTL1000_ENABLE_MASTER },
> + { NULL },
> +};
> +
> +static void mii_handle_override(struct mii_override *override_list,
> + struct phy_device *phydev, u16 *val, u16 *mask)
> +{
> + struct device *dev = &phydev->dev;
> + struct device_node *np = dev->of_node;
> + struct mii_override *override;
> + u32 tmp;
> +
> + if (!np && dev->parent->of_node)
> + np = dev->parent->of_node;
> +
> + if (!np)
> + return;
> +
> + for (override = &override_list[0]; override->prop != NULL; override++) {
> + if (!of_property_read_u32(np, override->prop, &tmp)) {
> + if (tmp) {
> + *val |= override->value;
> + phydev->advertising |= override->supported;
> + } else {
> + phydev->advertising &= ~(override->supported);
> + }
> +
> + *mask |= override->value;
> + }
> + }
> +
> + return;
> +}
> +
> +/**
> + * Provide phy register overrides from the device tree. Some hardware may
> + * be broken in interesting and board-specific ways, so we want a mechanism
> + * for the board data to provide overrides for default values. This should be
> + * called during phy init.
> + */
> +int of_get_mii_register(struct phy_device *phydev, int reg, u16 *val,
> + u16 *mask)
> +{
> + *val = 0;
> + *mask = 0;
> +
> + switch (reg) {
> + case MII_ADVERTISE:
> + mii_handle_override(mii_advertise_override, phydev, val, mask);
> + break;
> +
> + case MII_CTRL1000:
> + mii_handle_override(mii_gigabit_override, phydev, val, mask);
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL(of_get_mii_register);
> diff --git a/include/linux/of_net.h b/include/linux/of_net.h
> index 34597c8..2e478bc 100644
> --- a/include/linux/of_net.h
> +++ b/include/linux/of_net.h
> @@ -7,10 +7,14 @@
> #ifndef __LINUX_OF_NET_H
> #define __LINUX_OF_NET_H
>
> +#include <linux/phy.h>
> +
> #ifdef CONFIG_OF_NET
> #include <linux/of.h>
> extern int of_get_phy_mode(struct device_node *np);
> extern const void *of_get_mac_address(struct device_node *np);
> +extern int of_get_mii_register(struct phy_device *np, int reg, u16 *val,
> + u16 *mask);
> #else
> static inline int of_get_phy_mode(struct device_node *np)
> {
> @@ -21,6 +25,14 @@ static inline const void *of_get_mac_address(struct device_node *np)
> {
> return NULL;
> }
> +static inline int of_get_mii_register(struct phy_device *np, int reg, u16 *val,
> + u16 *mask)
> +{
> + *val = 0;
> + *mask = 0;
> +
> + return -EINVAL;
> +}
> #endif
>
> #endif /* __LINUX_OF_NET_H */
> --
> 1.8.4.2
>
> --
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Next message: Jean-Francois Moine: "Re: [PATCH v3 2/5] ASoC: tda998x: add a codec driver for theTDA998x"
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