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 = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0,
215 of_node_put(fixed_link_node);
217 if (PTR_ERR(gpiod) == -EPROBE_DEFER)
220 if (PTR_ERR(gpiod) != -ENOENT)
221 pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
229 static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
235 static struct phy_device *__fixed_phy_register(unsigned int irq,
236 struct fixed_phy_status *status,
237 struct device_node *np,
238 struct gpio_desc *gpiod)
240 struct fixed_mdio_bus *fmb = &platform_fmb;
241 struct phy_device *phy;
245 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
246 return ERR_PTR(-EPROBE_DEFER);
248 /* Check if we have a GPIO associated with this fixed phy */
250 gpiod = fixed_phy_get_gpiod(np);
252 return ERR_CAST(gpiod);
255 /* Get the next available PHY address, up to PHY_MAX_ADDR */
256 phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
258 return ERR_PTR(phy_addr);
260 ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod);
262 ida_simple_remove(&phy_fixed_ida, phy_addr);
266 phy = get_phy_device(fmb->mii_bus, phy_addr, false);
268 fixed_phy_del(phy_addr);
269 return ERR_PTR(-EINVAL);
272 /* propagate the fixed link values to struct phy_device */
273 phy->link = status->link;
275 phy->speed = status->speed;
276 phy->duplex = status->duplex;
277 phy->pause = status->pause;
278 phy->asym_pause = status->asym_pause;
282 phy->mdio.dev.of_node = np;
283 phy->is_pseudo_fixed_link = true;
285 switch (status->speed) {
287 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
289 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
293 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
295 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
300 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
302 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
306 phy_advertise_supported(phy);
308 ret = phy_device_register(phy);
310 phy_device_free(phy);
312 fixed_phy_del(phy_addr);
319 struct phy_device *fixed_phy_register(unsigned int irq,
320 struct fixed_phy_status *status,
321 struct device_node *np)
323 return __fixed_phy_register(irq, status, np, NULL);
325 EXPORT_SYMBOL_GPL(fixed_phy_register);
328 fixed_phy_register_with_gpiod(unsigned int irq,
329 struct fixed_phy_status *status,
330 struct gpio_desc *gpiod)
332 return __fixed_phy_register(irq, status, NULL, gpiod);
334 EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod);
336 void fixed_phy_unregister(struct phy_device *phy)
338 phy_device_remove(phy);
339 of_node_put(phy->mdio.dev.of_node);
340 fixed_phy_del(phy->mdio.addr);
342 EXPORT_SYMBOL_GPL(fixed_phy_unregister);
344 static int __init fixed_mdio_bus_init(void)
346 struct fixed_mdio_bus *fmb = &platform_fmb;
349 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
351 return PTR_ERR(pdev);
353 fmb->mii_bus = mdiobus_alloc();
354 if (fmb->mii_bus == NULL) {
356 goto err_mdiobus_reg;
359 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
360 fmb->mii_bus->name = "Fixed MDIO Bus";
361 fmb->mii_bus->priv = fmb;
362 fmb->mii_bus->parent = &pdev->dev;
363 fmb->mii_bus->read = &fixed_mdio_read;
364 fmb->mii_bus->write = &fixed_mdio_write;
366 ret = mdiobus_register(fmb->mii_bus);
368 goto err_mdiobus_alloc;
373 mdiobus_free(fmb->mii_bus);
375 platform_device_unregister(pdev);
378 module_init(fixed_mdio_bus_init);
380 static void __exit fixed_mdio_bus_exit(void)
382 struct fixed_mdio_bus *fmb = &platform_fmb;
383 struct fixed_phy *fp, *tmp;
385 mdiobus_unregister(fmb->mii_bus);
386 mdiobus_free(fmb->mii_bus);
387 platform_device_unregister(pdev);
389 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
393 ida_destroy(&phy_fixed_ida);
395 module_exit(fixed_mdio_bus_exit);
397 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
398 MODULE_AUTHOR("Vitaly Bordug");
399 MODULE_LICENSE("GPL");