1 // SPDX-License-Identifier: GPL-2.0+
3 * Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
5 * Author: Vitaly Bordug <vbordug@ru.mvista.com>
6 * Anton Vorontsov <avorontsov@ru.mvista.com>
8 * Copyright (c) 2006-2007 MontaVista Software, Inc.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/list.h>
15 #include <linux/mii.h>
16 #include <linux/phy.h>
17 #include <linux/phy_fixed.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
21 #include <linux/gpio/consumer.h>
22 #include <linux/seqlock.h>
23 #include <linux/idr.h>
24 #include <linux/netdevice.h>
25 #include <linux/linkmode.h>
29 struct fixed_mdio_bus {
30 struct mii_bus *mii_bus;
31 struct list_head phys;
36 struct phy_device *phydev;
38 struct fixed_phy_status status;
40 int (*link_update)(struct net_device *, struct fixed_phy_status *);
41 struct list_head node;
42 struct gpio_desc *link_gpiod;
45 static struct platform_device *pdev;
46 static struct fixed_mdio_bus platform_fmb = {
47 .phys = LIST_HEAD_INIT(platform_fmb.phys),
50 int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier)
52 struct fixed_mdio_bus *fmb = &platform_fmb;
53 struct phy_device *phydev = dev->phydev;
56 if (!phydev || !phydev->mdio.bus)
59 list_for_each_entry(fp, &fmb->phys, node) {
60 if (fp->addr == phydev->mdio.addr) {
61 fp->no_carrier = !new_carrier;
67 EXPORT_SYMBOL_GPL(fixed_phy_change_carrier);
69 static void fixed_phy_update(struct fixed_phy *fp)
71 if (!fp->no_carrier && fp->link_gpiod)
72 fp->status.link = !!gpiod_get_value_cansleep(fp->link_gpiod);
75 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
77 struct fixed_mdio_bus *fmb = bus->priv;
80 list_for_each_entry(fp, &fmb->phys, node) {
81 if (fp->addr == phy_addr) {
82 struct fixed_phy_status state;
86 s = read_seqcount_begin(&fp->seqcount);
87 fp->status.link = !fp->no_carrier;
88 /* Issue callback if user registered it. */
90 fp->link_update(fp->phydev->attached_dev,
92 /* Check the GPIO for change in status */
95 } while (read_seqcount_retry(&fp->seqcount, s));
97 return swphy_read_reg(reg_num, &state);
104 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
111 * If something weird is required to be done with link/speed,
112 * network driver is able to assign a function to implement this.
113 * May be useful for PHY's that need to be software-driven.
115 int fixed_phy_set_link_update(struct phy_device *phydev,
116 int (*link_update)(struct net_device *,
117 struct fixed_phy_status *))
119 struct fixed_mdio_bus *fmb = &platform_fmb;
120 struct fixed_phy *fp;
122 if (!phydev || !phydev->mdio.bus)
125 list_for_each_entry(fp, &fmb->phys, node) {
126 if (fp->addr == phydev->mdio.addr) {
127 fp->link_update = link_update;
135 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
137 static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr,
138 struct fixed_phy_status *status,
139 struct gpio_desc *gpiod)
142 struct fixed_mdio_bus *fmb = &platform_fmb;
143 struct fixed_phy *fp;
145 ret = swphy_validate_state(status);
149 fp = kzalloc(sizeof(*fp), GFP_KERNEL);
153 seqcount_init(&fp->seqcount);
156 fmb->mii_bus->irq[phy_addr] = irq;
159 fp->status = *status;
160 fp->link_gpiod = gpiod;
162 fixed_phy_update(fp);
164 list_add_tail(&fp->node, &fmb->phys);
169 int fixed_phy_add(unsigned int irq, int phy_addr,
170 struct fixed_phy_status *status) {
172 return fixed_phy_add_gpiod(irq, phy_addr, status, NULL);
174 EXPORT_SYMBOL_GPL(fixed_phy_add);
176 static DEFINE_IDA(phy_fixed_ida);
178 static void fixed_phy_del(int phy_addr)
180 struct fixed_mdio_bus *fmb = &platform_fmb;
181 struct fixed_phy *fp, *tmp;
183 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
184 if (fp->addr == phy_addr) {
187 gpiod_put(fp->link_gpiod);
189 ida_simple_remove(&phy_fixed_ida, phy_addr);
195 #ifdef CONFIG_OF_GPIO
196 static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
198 struct device_node *fixed_link_node;
199 struct gpio_desc *gpiod;
204 fixed_link_node = of_get_child_by_name(np, "fixed-link");
205 if (!fixed_link_node)
209 * As the fixed link is just a device tree node without any
210 * Linux device associated with it, we simply have obtain
211 * the GPIO descriptor from the device tree like this.
213 gpiod = fwnode_gpiod_get_index(of_fwnode_handle(fixed_link_node),
214 "link", 0, GPIOD_IN, "mdio");
215 if (IS_ERR(gpiod) && PTR_ERR(gpiod) != -EPROBE_DEFER) {
216 if (PTR_ERR(gpiod) != -ENOENT)
217 pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
221 of_node_put(fixed_link_node);
226 static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
232 static struct phy_device *__fixed_phy_register(unsigned int irq,
233 struct fixed_phy_status *status,
234 struct device_node *np,
235 struct gpio_desc *gpiod)
237 struct fixed_mdio_bus *fmb = &platform_fmb;
238 struct phy_device *phy;
242 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
243 return ERR_PTR(-EPROBE_DEFER);
245 /* Check if we have a GPIO associated with this fixed phy */
247 gpiod = fixed_phy_get_gpiod(np);
249 return ERR_CAST(gpiod);
252 /* Get the next available PHY address, up to PHY_MAX_ADDR */
253 phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
255 return ERR_PTR(phy_addr);
257 ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod);
259 ida_simple_remove(&phy_fixed_ida, phy_addr);
263 phy = get_phy_device(fmb->mii_bus, phy_addr, false);
265 fixed_phy_del(phy_addr);
266 return ERR_PTR(-EINVAL);
269 /* propagate the fixed link values to struct phy_device */
270 phy->link = status->link;
272 phy->speed = status->speed;
273 phy->duplex = status->duplex;
274 phy->pause = status->pause;
275 phy->asym_pause = status->asym_pause;
279 phy->mdio.dev.of_node = np;
280 phy->is_pseudo_fixed_link = true;
282 switch (status->speed) {
284 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
286 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
290 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
292 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
297 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
299 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
303 phy_advertise_supported(phy);
305 ret = phy_device_register(phy);
307 phy_device_free(phy);
309 fixed_phy_del(phy_addr);
316 struct phy_device *fixed_phy_register(unsigned int irq,
317 struct fixed_phy_status *status,
318 struct device_node *np)
320 return __fixed_phy_register(irq, status, np, NULL);
322 EXPORT_SYMBOL_GPL(fixed_phy_register);
325 fixed_phy_register_with_gpiod(unsigned int irq,
326 struct fixed_phy_status *status,
327 struct gpio_desc *gpiod)
329 return __fixed_phy_register(irq, status, NULL, gpiod);
331 EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod);
333 void fixed_phy_unregister(struct phy_device *phy)
335 phy_device_remove(phy);
336 of_node_put(phy->mdio.dev.of_node);
337 fixed_phy_del(phy->mdio.addr);
339 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
341 static int __init fixed_mdio_bus_init(void)
343 struct fixed_mdio_bus *fmb = &platform_fmb;
346 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
348 return PTR_ERR(pdev);
350 fmb->mii_bus = mdiobus_alloc();
351 if (fmb->mii_bus == NULL) {
353 goto err_mdiobus_reg;
356 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
357 fmb->mii_bus->name = "Fixed MDIO Bus";
358 fmb->mii_bus->priv = fmb;
359 fmb->mii_bus->parent = &pdev->dev;
360 fmb->mii_bus->read = &fixed_mdio_read;
361 fmb->mii_bus->write = &fixed_mdio_write;
363 ret = mdiobus_register(fmb->mii_bus);
365 goto err_mdiobus_alloc;
370 mdiobus_free(fmb->mii_bus);
372 platform_device_unregister(pdev);
375 module_init(fixed_mdio_bus_init);
377 static void __exit fixed_mdio_bus_exit(void)
379 struct fixed_mdio_bus *fmb = &platform_fmb;
380 struct fixed_phy *fp, *tmp;
382 mdiobus_unregister(fmb->mii_bus);
383 mdiobus_free(fmb->mii_bus);
384 platform_device_unregister(pdev);
386 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
390 ida_destroy(&phy_fixed_ida);
392 module_exit(fixed_mdio_bus_exit);
394 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
395 MODULE_AUTHOR("Vitaly Bordug");
396 MODULE_LICENSE("GPL");