[PATCH v2 1/4] mdio_bus: implement devm_mdiobus_alloc/devm_mdiobus_free

From: Grygorii Strashko
Date: Fri Apr 18 2014 - 12:37:29 EST


Add a resource managed devm_mdiobus_alloc()/devm_mdiobus_free()
to automatically clean up MDIO bus alocations made by MDIO drivers,
thus leading to simplified MDIO drivers code.

Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
Documentation/driver-model/devres.txt | 4 ++
drivers/net/phy/mdio_bus.c | 68 +++++++++++++++++++++++++++++++++
include/linux/phy.h | 2 +
3 files changed, 74 insertions(+)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 4f7897e..31aa066 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -308,3 +308,7 @@ SLAVE DMA ENGINE

SPI
devm_spi_register_master()
+
+MDIO
+ devm_mdiobus_alloc()
+ devm_mdiobus_free()
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 76f54b3..6412beb 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -69,6 +69,74 @@ struct mii_bus *mdiobus_alloc_size(size_t size)
}
EXPORT_SYMBOL(mdiobus_alloc_size);

+static void _devm_mdiobus_free(struct device *dev, void *res)
+{
+ mdiobus_free(*(struct mii_bus **)res);
+}
+
+static int devm_mdiobus_match(struct device *dev, void *res, void *data)
+{
+ struct mii_bus **r = res;
+
+ if (WARN_ON(!r || !*r))
+ return 0;
+
+ return *r == data;
+}
+
+/**
+ * devm_mdiobus_alloc - Resource-managed mdiobus_alloc_size()
+ * @dev: Device to allocate mii_bus for
+ * @sizeof_priv: Space to allocate for private structure.
+ *
+ * Managed mdiobus_alloc_size. mii_bus allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * If an mii_bus allocated with this function needs to be freed separately,
+ * devm_mdiobus_free() must be used.
+ *
+ * RETURNS:
+ * Pointer to allocated mii_bus on success, NULL on failure.
+ */
+struct mii_bus *devm_mdiobus_alloc(struct device *dev, int sizeof_priv)
+{
+ struct mii_bus **ptr, *bus;
+
+ ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ /* use raw alloc_dr for kmalloc caller tracing */
+ bus = mdiobus_alloc_size(sizeof_priv);
+ if (bus) {
+ *ptr = bus;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return bus;
+}
+EXPORT_SYMBOL_GPL(devm_mdiobus_alloc);
+
+/**
+ * devm_mdiobus_free - Resource-managed mdiobus_free()
+ * @dev: Device this mii_bus belongs to
+ * @bus: the mii_bus associated with the device
+ *
+ * Free mii_bus allocated with devm_mdiobus_alloc().
+ */
+void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
+{
+ int rc;
+
+ rc = devres_release(dev, _devm_mdiobus_free,
+ devm_mdiobus_match, bus);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_mdiobus_free);
+
/**
* mdiobus_release - mii_bus device release callback
* @d: the target struct device that contains the mii_bus
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 24126c4..2238bea 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -195,6 +195,8 @@ static inline struct mii_bus *mdiobus_alloc(void)
int mdiobus_register(struct mii_bus *bus);
void mdiobus_unregister(struct mii_bus *bus);
void mdiobus_free(struct mii_bus *bus);
+struct mii_bus *devm_mdiobus_alloc(struct device *dev, int sizeof_priv);
+void devm_mdiobus_free(struct device *dev, struct mii_bus *bus);
struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);
int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);
int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);
--
1.7.9.5

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