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[net-next,v2,02/14] net: phy: Introduce phy related fwnode functions

Message ID 20201215164315.3666-3-calvin.johnson@oss.nxp.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series ACPI support for dpaa2 driver | expand

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Commit Message

Calvin Johnson Dec. 15, 2020, 4:43 p.m. UTC
Define fwnode_phy_find_device() to iterate an mdiobus and find the
phy device of the provided phy fwnode. Additionally define
device_phy_find_device() to find phy device of provided device.

Define fwnode_get_phy_node() to get phy_node using named reference.

Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com>
---

Changes in v2:
- use reverse christmas tree ordering for local variables

 drivers/net/phy/phy_device.c | 64 ++++++++++++++++++++++++++++++++++++
 include/linux/phy.h          | 20 +++++++++++
 2 files changed, 84 insertions(+)

Comments

Andy Shevchenko Dec. 15, 2020, 5:23 p.m. UTC | #1
On Tue, Dec 15, 2020 at 6:44 PM Calvin Johnson
<calvin.johnson@oss.nxp.com> wrote:
>
> Define fwnode_phy_find_device() to iterate an mdiobus and find the
> phy device of the provided phy fwnode. Additionally define
> device_phy_find_device() to find phy device of provided device.
>
> Define fwnode_get_phy_node() to get phy_node using named reference.

...

> +#include <linux/acpi.h>

Not sure we need this. See below.

...

> +/**
> + * fwnode_phy_find_device - Find phy_device on the mdiobus for the provided
> + * phy_fwnode.

Can we keep a summary on one line?

> + * @phy_fwnode: Pointer to the phy's fwnode.
> + *
> + * If successful, returns a pointer to the phy_device with the embedded
> + * struct device refcount incremented by one, or NULL on failure.
> + */
> +struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode)
> +{
> +       struct mdio_device *mdiodev;
> +       struct device *d;

> +       if (!phy_fwnode)
> +               return NULL;

Why is this needed?
Perhaps a comment to the function description explains a case when
@phy_fwnode == NULL.

> +       d = bus_find_device_by_fwnode(&mdio_bus_type, phy_fwnode);
> +       if (d) {
> +               mdiodev = to_mdio_device(d);
> +               if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
> +                       return to_phy_device(d);
> +               put_device(d);
> +       }
> +
> +       return NULL;
> +}

...

> + * For ACPI, only "phy-handle" is supported. DT supports all the three
> + * named references to the phy node.

...

> +       /* Only phy-handle is used for ACPI */
> +       phy_node = fwnode_find_reference(fwnode, "phy-handle", 0);
> +       if (is_acpi_node(fwnode) || !IS_ERR(phy_node))
> +               return phy_node;

So, what is the problem with going through the rest on ACPI?
Usually we describe the restrictions in the documentation.
Calvin Johnson Dec. 17, 2020, 7:32 a.m. UTC | #2
On Tue, Dec 15, 2020 at 07:23:26PM +0200, Andy Shevchenko wrote:
> On Tue, Dec 15, 2020 at 6:44 PM Calvin Johnson
> <calvin.johnson@oss.nxp.com> wrote:
> >
> > Define fwnode_phy_find_device() to iterate an mdiobus and find the
> > phy device of the provided phy fwnode. Additionally define
> > device_phy_find_device() to find phy device of provided device.
> >
> > Define fwnode_get_phy_node() to get phy_node using named reference.
> 
> ...
> 
> > +#include <linux/acpi.h>
> 
> Not sure we need this. See below.

This is required to use is_acpi_node().
> 
> ...
> 
> > +/**
> > + * fwnode_phy_find_device - Find phy_device on the mdiobus for the provided
> > + * phy_fwnode.
> 
> Can we keep a summary on one line?

Ok
> 
> > + * @phy_fwnode: Pointer to the phy's fwnode.
> > + *
> > + * If successful, returns a pointer to the phy_device with the embedded
> > + * struct device refcount incremented by one, or NULL on failure.
> > + */
> > +struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode)
> > +{
> > +       struct mdio_device *mdiodev;
> > +       struct device *d;
> 
> > +       if (!phy_fwnode)
> > +               return NULL;
> 
> Why is this needed?
> Perhaps a comment to the function description explains a case when
> @phy_fwnode == NULL.

I think this function should be modified to follow of_phy_find_device() which
has NULL check. I'll add fwnode_mdio_find_device() also.
Here is a case where of_phy_find_device() is called without checking phy_np.
https://elixir.bootlin.com/linux/latest/source/drivers/net/ethernet/qualcomm/emac/emac-phy.c#L145
> 
> > +       d = bus_find_device_by_fwnode(&mdio_bus_type, phy_fwnode);
> > +       if (d) {
> > +               mdiodev = to_mdio_device(d);
> > +               if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
> > +                       return to_phy_device(d);
> > +               put_device(d);
> > +       }
> > +
> > +       return NULL;
> > +}
> 
> ...
> 
> > + * For ACPI, only "phy-handle" is supported. DT supports all the three
> > + * named references to the phy node.
> 
> ...
> 
> > +       /* Only phy-handle is used for ACPI */
> > +       phy_node = fwnode_find_reference(fwnode, "phy-handle", 0);
> > +       if (is_acpi_node(fwnode) || !IS_ERR(phy_node))
> > +               return phy_node;
> 
> So, what is the problem with going through the rest on ACPI?
> Usually we describe the restrictions in the documentation.

Others are legacy DT properties which are not intended to be supported
in ACPI. I can add this info in the document.

Thanks for the review, Andy!

Regards
Calvin
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 80c2e646c093..c153273606c1 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -9,6 +9,7 @@ 
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi.h>
 #include <linux/bitmap.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
@@ -2829,6 +2830,69 @@  static bool phy_drv_supports_irq(struct phy_driver *phydrv)
 	return phydrv->config_intr && phydrv->handle_interrupt;
 }
 
+/**
+ * fwnode_phy_find_device - Find phy_device on the mdiobus for the provided
+ * phy_fwnode.
+ * @phy_fwnode: Pointer to the phy's fwnode.
+ *
+ * If successful, returns a pointer to the phy_device with the embedded
+ * struct device refcount incremented by one, or NULL on failure.
+ */
+struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode)
+{
+	struct mdio_device *mdiodev;
+	struct device *d;
+
+	if (!phy_fwnode)
+		return NULL;
+
+	d = bus_find_device_by_fwnode(&mdio_bus_type, phy_fwnode);
+	if (d) {
+		mdiodev = to_mdio_device(d);
+		if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
+			return to_phy_device(d);
+		put_device(d);
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(fwnode_phy_find_device);
+
+/**
+ * device_phy_find_device - For the given device, get the phy_device
+ * @dev: Pointer to the given device
+ *
+ * Refer return conditions of fwnode_phy_find_device().
+ */
+struct phy_device *device_phy_find_device(struct device *dev)
+{
+	return fwnode_phy_find_device(dev_fwnode(dev));
+}
+EXPORT_SYMBOL_GPL(device_phy_find_device);
+
+/**
+ * fwnode_get_phy_node - Get the phy_node using the named reference.
+ * @fwnode: Pointer to fwnode from which phy_node has to be obtained.
+ *
+ * Refer return conditions of fwnode_find_reference().
+ * For ACPI, only "phy-handle" is supported. DT supports all the three
+ * named references to the phy node.
+ */
+struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *phy_node;
+
+	/* Only phy-handle is used for ACPI */
+	phy_node = fwnode_find_reference(fwnode, "phy-handle", 0);
+	if (is_acpi_node(fwnode) || !IS_ERR(phy_node))
+		return phy_node;
+	phy_node = fwnode_find_reference(fwnode, "phy", 0);
+	if (IS_ERR(phy_node))
+		phy_node = fwnode_find_reference(fwnode, "phy-device", 0);
+	return phy_node;
+}
+EXPORT_SYMBOL_GPL(fwnode_get_phy_node);
+
 /**
  * phy_probe - probe and init a PHY device
  * @dev: device to probe and init
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 381a95732b6a..7790a9a56d0f 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1341,10 +1341,30 @@  struct phy_device *phy_device_create(struct mii_bus *bus, int addr, u32 phy_id,
 				     bool is_c45,
 				     struct phy_c45_device_ids *c45_ids);
 #if IS_ENABLED(CONFIG_PHYLIB)
+struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode);
+struct phy_device *device_phy_find_device(struct device *dev);
+struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode);
 struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45);
 int phy_device_register(struct phy_device *phy);
 void phy_device_free(struct phy_device *phydev);
 #else
+static inline
+struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode)
+{
+	return NULL;
+}
+
+static inline struct phy_device *device_phy_find_device(struct device *dev)
+{
+	return NULL;
+}
+
+static inline
+struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode)
+{
+	return NULL;
+}
+
 static inline
 struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45)
 {