From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Implement a managed variant of of_mdiobus_register(). We need to
reimplement the devres structure and the release callback because we
can't put this function in drivers/net/phy/mdio_devres.c or we'd hit
circular dependencies between module symbols. We also don't want to
build this bit if OF is not selected in Kconfig.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
.../driver-api/driver-model/devres.rst | 1 +
drivers/of/of_mdio.c | 43 +++++++++++++++++++
include/linux/of_mdio.h | 3 ++
3 files changed, 47 insertions(+)
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index e0333d66a7f4..eaaaafc21134 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -343,6 +343,7 @@ MDIO
devm_mdiobus_alloc()
devm_mdiobus_alloc_size()
devm_mdiobus_register()
+ devm_of_mdiobus_register()
MEM
devm_free_pages()
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index a04afe79529c..83e98c6ec96b 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -330,6 +330,49 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
}
EXPORT_SYMBOL(of_mdiobus_register);
+/* This duplicates the devres code from drivers/net/phy/mdio_devres.c but
+ * if we put devm_of_mdiobus_register() over there we'd hit circular symbol
+ * dependencies between the libphy and of_mdio modules.
+ */
+struct mdiobus_devres {
+ struct mii_bus *mii;
+};
+
+static void devm_mdiobus_unregister(struct device *dev, void *this)
+{
+ struct mdiobus_devres *dr = this;
+
+ mdiobus_unregister(dr->mii);
+}
+
+/**
+ * devm_of_mdiobus_register - Resource managed variant of of_mdiobus_register()
+ * @dev: Device to register mii_bus for
+ * @mdio: MII bus structure to register
+ * @np: Device node to parse
+ */
+int devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
+ struct device_node *np)
+{
+ struct mdiobus_devres *dr;
+ int ret;
+
+ dr = devres_alloc(devm_mdiobus_unregister, sizeof(*dr), GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ ret = of_mdiobus_register(mdio, np);
+ if (ret) {
+ devres_free(dr);
+ return ret;
+ }
+
+ dr->mii = mdio;
+ devres_add(dev, dr);
+ return 0;
+}
+EXPORT_SYMBOL(devm_of_mdiobus_register);
+
/**
* of_phy_find_device - Give a PHY node, find the phy_device
* @phy_np: Pointer to the phy's device tree node
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index ba8e157f24ad..1efb88d9f892 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -8,12 +8,15 @@
#ifndef __LINUX_OF_MDIO_H
#define __LINUX_OF_MDIO_H
+#include <linux/device.h>
#include <linux/phy.h>
#include <linux/of.h>
#if IS_ENABLED(CONFIG_OF_MDIO)
bool of_mdiobus_child_is_phy(struct device_node *child);
int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np);
+int devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
+ struct device_node *np);
struct phy_device *of_phy_find_device(struct device_node *phy_np);
struct phy_device *
of_phy_connect(struct net_device *dev, struct device_node *phy_np,
--
2.26.1
