1 files changed, 391 insertions, 0 deletions
diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
new file mode 100644
index 0000000000..aef739c20a
--- /dev/null
+++ b/drivers/net/phy/fixed_phy.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
+ *
+ * Author: Vitaly Bordug <vbordug@ru.mvista.com>
+ *         Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * Copyright (c) 2006-2007 MontaVista Software, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+#include <linux/phy_fixed.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/gpio/consumer.h>
+#include <linux/idr.h>
+#include <linux/netdevice.h>
+#include <linux/linkmode.h>
+
+#include "swphy.h"
+
+struct fixed_mdio_bus {
+	struct mii_bus *mii_bus;
+	struct list_head phys;
+};
+
+struct fixed_phy {
+	int addr;
+	struct phy_device *phydev;
+	struct fixed_phy_status status;
+	bool no_carrier;
+	int (*link_update)(struct net_device *, struct fixed_phy_status *);
+	struct list_head node;
+	struct gpio_desc *link_gpiod;
+};
+
+static struct platform_device *pdev;
+static struct fixed_mdio_bus platform_fmb = {
+	.phys = LIST_HEAD_INIT(platform_fmb.phys),
+};
+
+int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct phy_device *phydev = dev->phydev;
+	struct fixed_phy *fp;
+
+	if (!phydev || !phydev->mdio.bus)
+		return -EINVAL;
+
+	list_for_each_entry(fp, &fmb->phys, node) {
+		if (fp->addr == phydev->mdio.addr) {
+			fp->no_carrier = !new_carrier;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(fixed_phy_change_carrier);
+
+static void fixed_phy_update(struct fixed_phy *fp)
+{
+	if (!fp->no_carrier && fp->link_gpiod)
+		fp->status.link = !!gpiod_get_value_cansleep(fp->link_gpiod);
+}
+
+static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
+{
+	struct fixed_mdio_bus *fmb = bus->priv;
+	struct fixed_phy *fp;
+
+	list_for_each_entry(fp, &fmb->phys, node) {
+		if (fp->addr == phy_addr) {
+			struct fixed_phy_status state;
+
+			fp->status.link = !fp->no_carrier;
+
+			/* Issue callback if user registered it. */
+			if (fp->link_update)
+				fp->link_update(fp->phydev->attached_dev,
+						&fp->status);
+
+			/* Check the GPIO for change in status */
+			fixed_phy_update(fp);
+			state = fp->status;
+
+			return swphy_read_reg(reg_num, &state);
+		}
+	}
+
+	return 0xFFFF;
+}
+
+static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
+			    u16 val)
+{
+	return 0;
+}
+
+/*
+ * If something weird is required to be done with link/speed,
+ * network driver is able to assign a function to implement this.
+ * May be useful for PHY's that need to be software-driven.
+ */
+int fixed_phy_set_link_update(struct phy_device *phydev,
+			      int (*link_update)(struct net_device *,
+						 struct fixed_phy_status *))
+{
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct fixed_phy *fp;
+
+	if (!phydev || !phydev->mdio.bus)
+		return -EINVAL;
+
+	list_for_each_entry(fp, &fmb->phys, node) {
+		if (fp->addr == phydev->mdio.addr) {
+			fp->link_update = link_update;
+			fp->phydev = phydev;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
+
+static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr,
+			       struct fixed_phy_status *status,
+			       struct gpio_desc *gpiod)
+{
+	int ret;
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct fixed_phy *fp;
+
+	ret = swphy_validate_state(status);
+	if (ret < 0)
+		return ret;
+
+	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
+	if (!fp)
+		return -ENOMEM;
+
+	if (irq != PHY_POLL)
+		fmb->mii_bus->irq[phy_addr] = irq;
+
+	fp->addr = phy_addr;
+	fp->status = *status;
+	fp->link_gpiod = gpiod;
+
+	fixed_phy_update(fp);
+
+	list_add_tail(&fp->node, &fmb->phys);
+
+	return 0;
+}
+
+int fixed_phy_add(unsigned int irq, int phy_addr,
+		  struct fixed_phy_status *status)
+{
+	return fixed_phy_add_gpiod(irq, phy_addr, status, NULL);
+}
+EXPORT_SYMBOL_GPL(fixed_phy_add);
+
+static DEFINE_IDA(phy_fixed_ida);
+
+static void fixed_phy_del(int phy_addr)
+{
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct fixed_phy *fp, *tmp;
+
+	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
+		if (fp->addr == phy_addr) {
+			list_del(&fp->node);
+			if (fp->link_gpiod)
+				gpiod_put(fp->link_gpiod);
+			kfree(fp);
+			ida_free(&phy_fixed_ida, phy_addr);
+			return;
+		}
+	}
+}
+
+#ifdef CONFIG_OF_GPIO
+static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
+{
+	struct device_node *fixed_link_node;
+	struct gpio_desc *gpiod;
+
+	if (!np)
+		return NULL;
+
+	fixed_link_node = of_get_child_by_name(np, "fixed-link");
+	if (!fixed_link_node)
+		return NULL;
+
+	/*
+	 * As the fixed link is just a device tree node without any
+	 * Linux device associated with it, we simply have obtain
+	 * the GPIO descriptor from the device tree like this.
+	 */
+	gpiod = fwnode_gpiod_get_index(of_fwnode_handle(fixed_link_node),
+				       "link", 0, GPIOD_IN, "mdio");
+	if (IS_ERR(gpiod) && PTR_ERR(gpiod) != -EPROBE_DEFER) {
+		if (PTR_ERR(gpiod) != -ENOENT)
+			pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
+			       fixed_link_node);
+		gpiod = NULL;
+	}
+	of_node_put(fixed_link_node);
+
+	return gpiod;
+}
+#else
+static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
+{
+	return NULL;
+}
+#endif
+
+static struct phy_device *__fixed_phy_register(unsigned int irq,
+					       struct fixed_phy_status *status,
+					       struct device_node *np,
+					       struct gpio_desc *gpiod)
+{
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct phy_device *phy;
+	int phy_addr;
+	int ret;
+
+	if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	/* Check if we have a GPIO associated with this fixed phy */
+	if (!gpiod) {
+		gpiod = fixed_phy_get_gpiod(np);
+		if (IS_ERR(gpiod))
+			return ERR_CAST(gpiod);
+	}
+
+	/* Get the next available PHY address, up to PHY_MAX_ADDR */
+	phy_addr = ida_alloc_max(&phy_fixed_ida, PHY_MAX_ADDR - 1, GFP_KERNEL);
+	if (phy_addr < 0)
+		return ERR_PTR(phy_addr);
+
+	ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod);
+	if (ret < 0) {
+		ida_free(&phy_fixed_ida, phy_addr);
+		return ERR_PTR(ret);
+	}
+
+	phy = get_phy_device(fmb->mii_bus, phy_addr, false);
+	if (IS_ERR(phy)) {
+		fixed_phy_del(phy_addr);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* propagate the fixed link values to struct phy_device */
+	phy->link = status->link;
+	if (status->link) {
+		phy->speed = status->speed;
+		phy->duplex = status->duplex;
+		phy->pause = status->pause;
+		phy->asym_pause = status->asym_pause;
+	}
+
+	of_node_get(np);
+	phy->mdio.dev.of_node = np;
+	phy->is_pseudo_fixed_link = true;
+
+	switch (status->speed) {
+	case SPEED_1000:
+		linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
+				 phy->supported);
+		linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
+				 phy->supported);
+		fallthrough;
+	case SPEED_100:
+		linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
+				 phy->supported);
+		linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
+				 phy->supported);
+		fallthrough;
+	case SPEED_10:
+	default:
+		linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
+				 phy->supported);
+		linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
+				 phy->supported);
+	}
+
+	phy_advertise_supported(phy);
+
+	ret = phy_device_register(phy);
+	if (ret) {
+		phy_device_free(phy);
+		of_node_put(np);
+		fixed_phy_del(phy_addr);
+		return ERR_PTR(ret);
+	}
+
+	return phy;
+}
+
+struct phy_device *fixed_phy_register(unsigned int irq,
+				      struct fixed_phy_status *status,
+				      struct device_node *np)
+{
+	return __fixed_phy_register(irq, status, np, NULL);
+}
+EXPORT_SYMBOL_GPL(fixed_phy_register);
+
+struct phy_device *
+fixed_phy_register_with_gpiod(unsigned int irq,
+			      struct fixed_phy_status *status,
+			      struct gpio_desc *gpiod)
+{
+	return __fixed_phy_register(irq, status, NULL, gpiod);
+}
+EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod);
+
+void fixed_phy_unregister(struct phy_device *phy)
+{
+	phy_device_remove(phy);
+	of_node_put(phy->mdio.dev.of_node);
+	fixed_phy_del(phy->mdio.addr);
+}
+EXPORT_SYMBOL_GPL(fixed_phy_unregister);
+
+static int __init fixed_mdio_bus_init(void)
+{
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	int ret;
+
+	pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	fmb->mii_bus = mdiobus_alloc();
+	if (fmb->mii_bus == NULL) {
+		ret = -ENOMEM;
+		goto err_mdiobus_reg;
+	}
+
+	snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
+	fmb->mii_bus->name = "Fixed MDIO Bus";
+	fmb->mii_bus->priv = fmb;
+	fmb->mii_bus->parent = &pdev->dev;
+	fmb->mii_bus->read = &fixed_mdio_read;
+	fmb->mii_bus->write = &fixed_mdio_write;
+	fmb->mii_bus->phy_mask = ~0;
+
+	ret = mdiobus_register(fmb->mii_bus);
+	if (ret)
+		goto err_mdiobus_alloc;
+
+	return 0;
+
+err_mdiobus_alloc:
+	mdiobus_free(fmb->mii_bus);
+err_mdiobus_reg:
+	platform_device_unregister(pdev);
+	return ret;
+}
+module_init(fixed_mdio_bus_init);
+
+static void __exit fixed_mdio_bus_exit(void)
+{
+	struct fixed_mdio_bus *fmb = &platform_fmb;
+	struct fixed_phy *fp, *tmp;
+
+	mdiobus_unregister(fmb->mii_bus);
+	mdiobus_free(fmb->mii_bus);
+	platform_device_unregister(pdev);
+
+	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
+		list_del(&fp->node);
+		kfree(fp);
+	}
+	ida_destroy(&phy_fixed_ida);
+}
+module_exit(fixed_mdio_bus_exit);
+
+MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
+MODULE_AUTHOR("Vitaly Bordug");
+MODULE_LICENSE("GPL");