.../ABI/testing/sysfs-class-net-phydev | 10 +++ drivers/net/phy/phy_device.c | 62 ++++++++++++++++++- 2 files changed, 70 insertions(+), 2 deletions(-)
The phy_id field only shows the PHY ID of the C22 device, and the C45
device did not store its PHY ID in this field.
Add a new phy_mmd_group, and export the mmd<n>_device_id for the C45
device. These files are invisible to the C22 device.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
v2: Only one value for per file and invisible to the C22 device.
v1: https://lore.kernel.org/all/20250523132606.2814-1-yajun.deng@linux.dev/
---
.../ABI/testing/sysfs-class-net-phydev | 10 +++
drivers/net/phy/phy_device.c | 62 ++++++++++++++++++-
2 files changed, 70 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-class-net-phydev b/Documentation/ABI/testing/sysfs-class-net-phydev
index ac722dd5e694..31615c59bff9 100644
--- a/Documentation/ABI/testing/sysfs-class-net-phydev
+++ b/Documentation/ABI/testing/sysfs-class-net-phydev
@@ -26,6 +26,16 @@ Description:
This ID is used to match the device with the appropriate
driver.
+What: /sys/class/mdio_bus/<bus>/<device>/c45_phy_ids/mmd<n>_device_id
+Date: June 2025
+KernelVersion: 6.17
+Contact: netdev@vger.kernel.org
+Description:
+ This attribute contains the 32-bit PHY Identifier as reported
+ by the device during bus enumeration, encoded in hexadecimal.
+ These C45 IDs are used to match the device with the appropriate
+ driver. These files are invisible to the C22 device.
+
What: /sys/class/mdio_bus/<bus>/<device>/phy_interface
Date: February 2014
KernelVersion: 3.15
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 73f9cb2e2844..5e5bac8d8651 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -645,11 +645,69 @@ static struct attribute *phy_dev_attrs[] = {
&dev_attr_phy_dev_flags.attr,
NULL,
};
-ATTRIBUTE_GROUPS(phy_dev);
+
+static const struct attribute_group phy_dev_group = {
+ .attrs = phy_dev_attrs,
+};
+
+#define MMD_INDICES \
+ _(1) _(2) _(3) _(4) _(5) _(6) _(7) _(8) \
+ _(9) _(10) _(11) _(12) _(13) _(14) _(15) _(16) \
+ _(17) _(18) _(19) _(20) _(21) _(22) _(23) _(24) \
+ _(25) _(26) _(27) _(28) _(29) _(30) _(31)
+
+#define MMD_DEVICE_ID_ATTR(n) \
+static ssize_t mmd##n##_device_id_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ struct phy_device *phydev = to_phy_device(dev); \
+ return sysfs_emit(buf, "0x%.8lx\n", \
+ (unsigned long)phydev->c45_ids.device_ids[n]); \
+} \
+static DEVICE_ATTR_RO(mmd##n##_device_id)
+
+#define _(x) MMD_DEVICE_ID_ATTR(x);
+MMD_INDICES
+#undef _
+
+static struct attribute *phy_mmd_attrs[] = {
+ #define _(x) &dev_attr_mmd##x##_device_id.attr,
+ MMD_INDICES
+ #undef _
+ NULL
+};
+
+static umode_t phy_mmd_is_visible(struct kobject *kobj,
+ struct attribute *attr, int index)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct phy_device *phydev = to_phy_device(dev);
+ const int i = index + 1;
+
+ if (!phydev->is_c45)
+ return 0;
+ if (i >= ARRAY_SIZE(phydev->c45_ids.device_ids) ||
+ phydev->c45_ids.device_ids[i] == 0xffffffff)
+ return 0;
+
+ return attr->mode;
+}
+
+static const struct attribute_group phy_mmd_group = {
+ .name = "c45_phy_ids",
+ .attrs = phy_mmd_attrs,
+ .is_visible = phy_mmd_is_visible,
+};
+
+static const struct attribute_group *phy_device_groups[] = {
+ &phy_dev_group,
+ &phy_mmd_group,
+ NULL,
+};
static const struct device_type mdio_bus_phy_type = {
.name = "PHY",
- .groups = phy_dev_groups,
+ .groups = phy_device_groups,
.release = phy_device_release,
.pm = pm_ptr(&mdio_bus_phy_pm_ops),
};
--
2.25.1> +#define MMD_INDICES \
> + _(1) _(2) _(3) _(4) _(5) _(6) _(7) _(8) \
> + _(9) _(10) _(11) _(12) _(13) _(14) _(15) _(16) \
> + _(17) _(18) _(19) _(20) _(21) _(22) _(23) _(24) \
> + _(25) _(26) _(27) _(28) _(29) _(30) _(31)
Is 0 not valid?
> +#define MMD_DEVICE_ID_ATTR(n) \
> +static ssize_t mmd##n##_device_id_show(struct device *dev, \
> + struct device_attribute *attr, char *buf) \
> +{ \
> + struct phy_device *phydev = to_phy_device(dev); \
> + return sysfs_emit(buf, "0x%.8lx\n", \
> + (unsigned long)phydev->c45_ids.device_ids[n]); \
> +} \
> +static DEVICE_ATTR_RO(mmd##n##_device_id)
This macro magic i can follow, you see this quite a bit in the kernel.
> +
> +#define _(x) MMD_DEVICE_ID_ATTR(x);
> +MMD_INDICES
> +#undef _
> +
> +static struct attribute *phy_mmd_attrs[] = {
> + #define _(x) &dev_attr_mmd##x##_device_id.attr,
> + MMD_INDICES
> + #undef _
> + NULL
> +};
If i squint at this enough, i can work it out, but generally a much
more readable KISS approach is taken, of just invoking a macro 32
times. See mdio_bus.c as an example.
Andrew
---
pw-bot: cr
June 12, 2025 at 11:31 PM, "Andrew Lunn" <andrew@lunn.ch> wrote:
>
> >
> > +#define MMD_INDICES \
> >
> > + _(1) _(2) _(3) _(4) _(5) _(6) _(7) _(8) \
> >
> > + _(9) _(10) _(11) _(12) _(13) _(14) _(15) _(16) \
> >
> > + _(17) _(18) _(19) _(20) _(21) _(22) _(23) _(24) \
> >
> > + _(25) _(26) _(27) _(28) _(29) _(30) _(31)
> >
>
> Is 0 not valid?
>
Yes, the MMD starts at 1. See "include/uapi/linux/mdio.h".
> >
> > +#define MMD_DEVICE_ID_ATTR(n) \
> >
> > +static ssize_t mmd##n##_device_id_show(struct device *dev, \
> >
> > + struct device_attribute *attr, char *buf) \
> >
> > +{ \
> >
> > + struct phy_device *phydev = to_phy_device(dev); \
> >
> > + return sysfs_emit(buf, "0x%.8lx\n", \
> >
> > + (unsigned long)phydev->c45_ids.device_ids[n]); \
> >
> > +} \
> >
> > +static DEVICE_ATTR_RO(mmd##n##_device_id)
> >
>
> This macro magic i can follow, you see this quite a bit in the kernel.
>
Okay.
> >
> > +
> >
> > +#define _(x) MMD_DEVICE_ID_ATTR(x);
> >
> > +MMD_INDICES
> >
> > +#undef _
> >
> > +
> >
> > +static struct attribute *phy_mmd_attrs[] = {
> >
> > + #define _(x) &dev_attr_mmd##x##_device_id.attr,
> >
> > + MMD_INDICES
> >
> > + #undef _
> >
> > + NULL
> >
> > +};
> >
>
> If i squint at this enough, i can work it out, but generally a much
>
> more readable KISS approach is taken, of just invoking a macro 32
>
> times. See mdio_bus.c as an example.
>
Okay.
> Andrew
>
> ---
>
> pw-bot: cr
>
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