net: mdio: Add ACPI support code for mdio

Define acpi_mdiobus_register() to Register mii_bus and create PHYs for
each ACPI child node.

Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Grant Likely <grant.likely@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/MAINTAINERS b/MAINTAINERS
index e8f8b6c..2172f59 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6811,6 +6811,7 @@ F:        Documentation/devicetree/bindings/net/mdio*
 F:     Documentation/devicetree/bindings/net/qca,ar803x.yaml
 F:     Documentation/networking/phy.rst
 F:     drivers/net/mdio/
+F:     drivers/net/mdio/acpi_mdio.c
 F:     drivers/net/mdio/fwnode_mdio.c
 F:     drivers/net/mdio/of_mdio.c
 F:     drivers/net/pcs/

diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig
index 422e9e0..99a6c13 100644 (file)
--- a/drivers/net/mdio/Kconfig
+++ b/drivers/net/mdio/Kconfig
@@ -34,6 +34,13 @@ config OF_MDIO
        help
          OpenFirmware MDIO bus (Ethernet PHY) accessors
 
+config ACPI_MDIO
+       def_tristate PHYLIB
+       depends on ACPI
+       depends on PHYLIB
+       help
+         ACPI MDIO bus (Ethernet PHY) accessors
+
 if MDIO_BUS
 
 config MDIO_DEVRES

diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile
index 2e6813c..15f8dc4 100644 (file)
--- a/drivers/net/mdio/Makefile
+++ b/drivers/net/mdio/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for Linux MDIO bus drivers
 
+obj-$(CONFIG_ACPI_MDIO)                += acpi_mdio.o
 obj-$(CONFIG_FWNODE_MDIO)      += fwnode_mdio.o
 obj-$(CONFIG_OF_MDIO)          += of_mdio.o
 

diff --git a/drivers/net/mdio/acpi_mdio.c b/drivers/net/mdio/acpi_mdio.c
new file mode 100644 (file)
index 0000000..d77c987
--- /dev/null
+++ b/drivers/net/mdio/acpi_mdio.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ACPI helpers for the MDIO (Ethernet PHY) API
+ *
+ * This file provides helper functions for extracting PHY device information
+ * out of the ACPI ASL and using it to populate an mii_bus.
+ */
+
+#include <linux/acpi.h>
+#include <linux/acpi_mdio.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/fwnode_mdio.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+MODULE_AUTHOR("Calvin Johnson <calvin.johnson@oss.nxp.com>");
+MODULE_LICENSE("GPL");
+
+/**
+ * acpi_mdiobus_register - Register mii_bus and create PHYs from the ACPI ASL.
+ * @mdio: pointer to mii_bus structure
+ * @fwnode: pointer to fwnode of MDIO bus. This fwnode is expected to represent
+ * an ACPI device object corresponding to the MDIO bus and its children are
+ * expected to correspond to the PHY devices on that bus.
+ *
+ * This function registers the mii_bus structure and registers a phy_device
+ * for each child node of @fwnode.
+ */
+int acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode)
+{
+       struct fwnode_handle *child;
+       u32 addr;
+       int ret;
+
+       /* Mask out all PHYs from auto probing. */
+       mdio->phy_mask = GENMASK(31, 0);
+       ret = mdiobus_register(mdio);
+       if (ret)
+               return ret;
+
+       ACPI_COMPANION_SET(&mdio->dev, to_acpi_device_node(fwnode));
+
+       /* Loop over the child nodes and register a phy_device for each PHY */
+       fwnode_for_each_child_node(fwnode, child) {
+               ret = acpi_get_local_address(ACPI_HANDLE_FWNODE(child), &addr);
+               if (ret || addr >= PHY_MAX_ADDR)
+                       continue;
+
+               ret = fwnode_mdiobus_register_phy(mdio, child, addr);
+               if (ret == -ENODEV)
+                       dev_err(&mdio->dev,
+                               "MDIO device at address %d is missing.\n",
+                               addr);
+       }
+       return 0;
+}
+EXPORT_SYMBOL(acpi_mdiobus_register);

diff --git a/include/linux/acpi_mdio.h b/include/linux/acpi_mdio.h
new file mode 100644 (file)
index 0000000..0a24ab7
--- /dev/null
+++ b/include/linux/acpi_mdio.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * ACPI helper for the MDIO (Ethernet PHY) API
+ */
+
+#ifndef __LINUX_ACPI_MDIO_H
+#define __LINUX_ACPI_MDIO_H
+
+#include <linux/phy.h>
+
+#if IS_ENABLED(CONFIG_ACPI_MDIO)
+int acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode);
+#else /* CONFIG_ACPI_MDIO */
+static inline int
+acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode)
+{
+       /*
+        * Fall back to mdiobus_register() function to register a bus.
+        * This way, we don't have to keep compat bits around in drivers.
+        */
+
+       return mdiobus_register(mdio);
+}
+#endif
+
+#endif /* __LINUX_ACPI_MDIO_H */