Message-Id: <1513588684-15647-4-git-send-email-mw@semihalf.com>
Date:   Mon, 18 Dec 2017 10:17:59 +0100
From:   Marcin Wojtas <mw@...ihalf.com>
To:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        netdev@...r.kernel.org
Cc:     davem@...emloft.net, linux@....linux.org.uk,
        rafael.j.wysocki@...el.com, andrew@...n.ch, f.fainelli@...il.com,
        antoine.tenart@...e-electrons.com,
        thomas.petazzoni@...e-electrons.com,
        gregory.clement@...e-electrons.com,
        ezequiel.garcia@...e-electrons.com, nadavh@...vell.com,
        neta@...vell.com, ard.biesheuvel@...aro.org, mw@...ihalf.com,
        jaz@...ihalf.com, tn@...ihalf.com
Subject: [net-next: PATCH 3/8] mdio_bus: Introduce fwnode MDIO helpers

This patch introduces fwnode helper for registering MDIO
bus, as well as one for finding the PHY, basing on its
firmware node pointer. Comparing to existing OF equivalent,
fwnode_mdiobus_register() does not support:
 * deprecated bindings (device whitelist, nor the PHY ID embedded
   in the compatible string)
 * MDIO bus auto scanning

Signed-off-by: Marcin Wojtas <mw@...ihalf.com>
---
 drivers/net/phy/mdio_bus.c | 218 ++++++++++++++++++++
 include/linux/mdio.h       |   3 +
 2 files changed, 221 insertions(+)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index a0f34c3..f2b2a94 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -27,6 +27,7 @@
 #include <linux/of_device.h>
 #include <linux/of_mdio.h>
 #include <linux/of_gpio.h>
+#include <linux/of_irq.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
@@ -662,6 +663,223 @@ static int mdio_uevent(struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
+static int fwnode_mdiobus_register_phy(struct mii_bus *bus,
+				       struct fwnode_handle *child, u32 addr)
+{
+	struct phy_device *phy;
+	bool is_c45 = false;
+	int rc;
+
+	rc = fwnode_property_match_string(child, "compatible",
+					  "ethernet-phy-ieee802.3-c45");
+	if (!rc)
+		is_c45 = true;
+
+	phy = get_phy_device(bus, addr, is_c45);
+	if (IS_ERR(phy))
+		return PTR_ERR(phy);
+
+	phy->irq = bus->irq[addr];
+
+	if (to_of_node(child)) {
+		rc = of_irq_get(to_of_node(child), 0);
+		if (rc == -EPROBE_DEFER) {
+			phy_device_free(phy);
+			return rc;
+		} else if (rc > 0) {
+			phy->irq = rc;
+			bus->irq[addr] = rc;
+		}
+	}
+
+	if (fwnode_property_read_bool(child, "broken-turn-around"))
+		bus->phy_ignore_ta_mask |= 1 << addr;
+
+	/* Associate the fwnode with the device structure so it
+	 * can be looked up later.
+	 */
+	phy->mdio.dev.fwnode = child;
+
+	/* All data is now stored in the phy struct, so register it */
+	rc = phy_device_register(phy);
+	if (rc) {
+		phy_device_free(phy);
+		fwnode_handle_put(child);
+		return rc;
+	}
+
+	dev_dbg(&bus->dev, "registered phy at address %i\n", addr);
+
+	return 0;
+}
+
+static int fwnode_mdiobus_register_device(struct mii_bus *bus,
+					  struct fwnode_handle *child, u32 addr)
+{
+	struct mdio_device *mdiodev;
+	int rc;
+
+	mdiodev = mdio_device_create(bus, addr);
+	if (IS_ERR(mdiodev))
+		return PTR_ERR(mdiodev);
+
+	/* Associate the fwnode with the device structure so it
+	 * can be looked up later.
+	 */
+	mdiodev->dev.fwnode = child;
+
+	/* All data is now stored in the mdiodev struct; register it. */
+	rc = mdio_device_register(mdiodev);
+	if (rc) {
+		mdio_device_free(mdiodev);
+		fwnode_handle_put(child);
+		return rc;
+	}
+
+	dev_dbg(&bus->dev, "registered mdio device at address %i\n", addr);
+
+	return 0;
+}
+
+static int fwnode_mdio_parse_addr(struct device *dev,
+				  const struct fwnode_handle *fwnode)
+{
+	u32 addr;
+	int ret;
+
+	ret = fwnode_property_read_u32(fwnode, "reg", &addr);
+	if (ret < 0) {
+		dev_err(dev, "PHY node has no 'reg' property\n");
+		return ret;
+	}
+
+	/* A PHY must have a reg property in the range [0-31] */
+	if (addr < 0 || addr >= PHY_MAX_ADDR) {
+		dev_err(dev, "PHY address %i is invalid\n", addr);
+		return -EINVAL;
+	}
+
+	return addr;
+}
+
+/**
+ * fwnode_mdiobus_child_is_phy - Return true if the child is a PHY node.
+ * It must either:
+ * o Compatible string of "ethernet-phy-ieee802.3-c45"
+ * o Compatible string of "ethernet-phy-ieee802.3-c22"
+ * Checking "compatible" property is done, in order to follow the DT binding.
+ */
+static bool fwnode_mdiobus_child_is_phy(struct fwnode_handle *child)
+{
+	int ret;
+
+	ret = fwnode_property_match_string(child, "compatible",
+					   "ethernet-phy-ieee802.3-c45");
+	if (!ret)
+		return true;
+
+	ret = fwnode_property_match_string(child, "compatible",
+					   "ethernet-phy-ieee802.3-c22");
+	if (!ret)
+		return true;
+
+	if (!fwnode_property_present(child, "compatible"))
+		return true;
+
+	return false;
+}
+
+/**
+ * fwnode_mdiobus_register - Register mii_bus and create PHYs from the fwnode
+ * @bus: pointer to mii_bus structure
+ * @fwnode: pointer to fwnode_handle of MDIO bus.
+ *
+ * This function registers the mii_bus structure and registers a phy_device
+ * for each child node of @fwnode.
+ */
+int fwnode_mdiobus_register(struct mii_bus *bus, struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *child;
+	int addr, rc;
+	int default_gpio_reset_delay_ms = 10;
+
+	/* Do not continue if the node is disabled */
+	if (!fwnode_device_is_available(fwnode))
+		return -ENODEV;
+
+	/* Mask out all PHYs from auto probing. Instead the PHYs listed in
+	 * the firmware nodes are populated after the bus has been registered.
+	 */
+	bus->phy_mask = ~0;
+
+	bus->dev.fwnode = fwnode;
+
+	/* Get bus level PHY reset GPIO details */
+	bus->reset_delay_us = default_gpio_reset_delay_ms;
+	fwnode_property_read_u32(fwnode, "reset-delay-us",
+				 &bus->reset_delay_us);
+
+	/* Register the MDIO bus */
+	rc = mdiobus_register(bus);
+	if (rc)
+		return rc;
+
+	/* Loop over the child nodes and register a phy_device for each PHY */
+	fwnode_for_each_child_node(fwnode, child) {
+		addr = fwnode_mdio_parse_addr(&bus->dev, child);
+		if (addr < 0)
+			continue;
+
+		if (fwnode_mdiobus_child_is_phy(child))
+			rc = fwnode_mdiobus_register_phy(bus, child, addr);
+		else
+			rc = fwnode_mdiobus_register_device(bus, child, addr);
+		if (rc)
+			goto unregister;
+	}
+
+	return 0;
+
+unregister:
+	mdiobus_unregister(bus);
+
+	return rc;
+}
+EXPORT_SYMBOL(fwnode_mdiobus_register);
+
+/* Helper function for fwnode_phy_find_device */
+static int fwnode_phy_match(struct device *dev, void *phy_fwnode)
+{
+	return dev->fwnode == phy_fwnode;
+}
+
+/**
+ * fwnode_phy_find_device - find the phy_device associated to 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 device *d;
+	struct mdio_device *mdiodev;
+
+	if (!phy_fwnode)
+		return NULL;
+
+	d = bus_find_device(&mdio_bus_type, NULL, phy_fwnode, fwnode_phy_match);
+	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);
+
 #ifdef CONFIG_PM
 static int mdio_bus_suspend(struct device *dev)
 {
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index e37c21d..286ec12 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -272,6 +272,9 @@ int mdiobus_unregister_device(struct mdio_device *mdiodev);
 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr);
 struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr);
 
+int fwnode_mdiobus_register(struct mii_bus *bus, struct fwnode_handle *fwnode);
+struct phy_device *fwnode_phy_find_device(struct fwnode_handle *phy_fwnode);
+
 /**
  * mdio_module_driver() - Helper macro for registering mdio drivers
  *
-- 
2.7.4

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