// 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/seqlock.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; seqcount_t seqcount; 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; int s; do { s = read_seqcount_begin(&fp->seqcount); 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; } while (read_seqcount_retry(&fp->seqcount, s)); 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; seqcount_init(&fp->seqcount); 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_simple_remove(&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 = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0, GPIOD_IN, "mdio"); of_node_put(fixed_link_node); if (IS_ERR(gpiod)) { if (PTR_ERR(gpiod) == -EPROBE_DEFER) return gpiod; pr_err("error getting GPIO for fixed link %pOF, proceed without\n", fixed_link_node); gpiod = NULL; } 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_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, 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_simple_remove(&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); /* fall through */ 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); /* fall through */ 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); } linkmode_copy(phy->advertising, phy->supported); 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; 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");