|  | // 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_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 = 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_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); | 
|  | 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; | 
|  |  | 
|  | 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"); |