[PATCH net-next v8 11/15] net: mdio: Add ACPI support code for mdio

From: Ioana Ciornei
Date: Thu Jun 10 2021 - 12:42:32 EST


From: Calvin Johnson <calvin.johnson@xxxxxxxxxxx>

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

Signed-off-by: Calvin Johnson <calvin.johnson@xxxxxxxxxxx>
Signed-off-by: Ioana Ciornei <ioana.ciornei@xxxxxxx>
---

Changes in v8: None
Changes in v7:
- Include headers directly used in acpi_mdio.c

Changes in v6:
- use GENMASK() and ACPI_COMPANION_SET()
- some cleanup
- remove unwanted header inclusion

Changes in v5:
- add missing MODULE_LICENSE()
- replace fwnode_get_id() with OF and ACPI function calls

Changes in v4: None
Changes in v3: None
Changes in v2: None

MAINTAINERS | 1 +
drivers/net/mdio/Kconfig | 7 +++++
drivers/net/mdio/Makefile | 1 +
drivers/net/mdio/acpi_mdio.c | 56 ++++++++++++++++++++++++++++++++++++
include/linux/acpi_mdio.h | 26 +++++++++++++++++
5 files changed, 91 insertions(+)
create mode 100644 drivers/net/mdio/acpi_mdio.c
create mode 100644 include/linux/acpi_mdio.h

diff --git a/MAINTAINERS b/MAINTAINERS
index e8f8b6c33a51..2172f594be8f 100644
--- 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 422e9e042a3c..99a6c13a11af 100644
--- 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 2e6813c709eb..15f8dc4042ce 100644
--- 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
index 000000000000..60a86e3fc246
--- /dev/null
+++ b/drivers/net/mdio/acpi_mdio.c
@@ -0,0 +1,56 @@
+// 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@xxxxxxxxxxx>");
+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 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
index 000000000000..0a24ab7cb66f
--- /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 */
--
2.31.1