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1/*
2 * Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
3 *
4 * Author: Vitaly Bordug <vbordug@ru.mvista.com>
5 * Anton Vorontsov <avorontsov@ru.mvista.com>
6 *
7 * Copyright (c) 2006-2007 MontaVista Software, Inc.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/list.h>
19#include <linux/mii.h>
20#include <linux/phy.h>
21#include <linux/phy_fixed.h>
22#include <linux/err.h>
23#include <linux/slab.h>
24#include <linux/of.h>
25#include <linux/gpio.h>
26#include <linux/seqlock.h>
27#include <linux/idr.h>
28
29#include "swphy.h"
30
31struct fixed_mdio_bus {
32 struct mii_bus *mii_bus;
33 struct list_head phys;
34};
35
36struct fixed_phy {
37 int addr;
38 struct phy_device *phydev;
39 seqcount_t seqcount;
40 struct fixed_phy_status status;
41 int (*link_update)(struct net_device *, struct fixed_phy_status *);
42 struct list_head node;
43 int link_gpio;
44};
45
46static struct platform_device *pdev;
47static struct fixed_mdio_bus platform_fmb = {
48 .phys = LIST_HEAD_INIT(platform_fmb.phys),
49};
50
51static void fixed_phy_update(struct fixed_phy *fp)
52{
53 if (gpio_is_valid(fp->link_gpio))
54 fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
55}
56
57static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
58{
59 struct fixed_mdio_bus *fmb = bus->priv;
60 struct fixed_phy *fp;
61
62 list_for_each_entry(fp, &fmb->phys, node) {
63 if (fp->addr == phy_addr) {
64 struct fixed_phy_status state;
65 int s;
66
67 do {
68 s = read_seqcount_begin(&fp->seqcount);
69 /* Issue callback if user registered it. */
70 if (fp->link_update) {
71 fp->link_update(fp->phydev->attached_dev,
72 &fp->status);
73 fixed_phy_update(fp);
74 }
75 state = fp->status;
76 } while (read_seqcount_retry(&fp->seqcount, s));
77
78 return swphy_read_reg(reg_num, &state);
79 }
80 }
81
82 return 0xFFFF;
83}
84
85static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
86 u16 val)
87{
88 return 0;
89}
90
91/*
92 * If something weird is required to be done with link/speed,
93 * network driver is able to assign a function to implement this.
94 * May be useful for PHY's that need to be software-driven.
95 */
96int fixed_phy_set_link_update(struct phy_device *phydev,
97 int (*link_update)(struct net_device *,
98 struct fixed_phy_status *))
99{
100 struct fixed_mdio_bus *fmb = &platform_fmb;
101 struct fixed_phy *fp;
102
103 if (!phydev || !phydev->mdio.bus)
104 return -EINVAL;
105
106 list_for_each_entry(fp, &fmb->phys, node) {
107 if (fp->addr == phydev->mdio.addr) {
108 fp->link_update = link_update;
109 fp->phydev = phydev;
110 return 0;
111 }
112 }
113
114 return -ENOENT;
115}
116EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
117
118int fixed_phy_add(unsigned int irq, int phy_addr,
119 struct fixed_phy_status *status,
120 int link_gpio)
121{
122 int ret;
123 struct fixed_mdio_bus *fmb = &platform_fmb;
124 struct fixed_phy *fp;
125
126 ret = swphy_validate_state(status);
127 if (ret < 0)
128 return ret;
129
130 fp = kzalloc(sizeof(*fp), GFP_KERNEL);
131 if (!fp)
132 return -ENOMEM;
133
134 seqcount_init(&fp->seqcount);
135
136 if (irq != PHY_POLL)
137 fmb->mii_bus->irq[phy_addr] = irq;
138
139 fp->addr = phy_addr;
140 fp->status = *status;
141 fp->link_gpio = link_gpio;
142
143 if (gpio_is_valid(fp->link_gpio)) {
144 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
145 "fixed-link-gpio-link");
146 if (ret)
147 goto err_regs;
148 }
149
150 fixed_phy_update(fp);
151
152 list_add_tail(&fp->node, &fmb->phys);
153
154 return 0;
155
156err_regs:
157 kfree(fp);
158 return ret;
159}
160EXPORT_SYMBOL_GPL(fixed_phy_add);
161
162static DEFINE_IDA(phy_fixed_ida);
163
164static void fixed_phy_del(int phy_addr)
165{
166 struct fixed_mdio_bus *fmb = &platform_fmb;
167 struct fixed_phy *fp, *tmp;
168
169 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
170 if (fp->addr == phy_addr) {
171 list_del(&fp->node);
172 if (gpio_is_valid(fp->link_gpio))
173 gpio_free(fp->link_gpio);
174 kfree(fp);
175 ida_simple_remove(&phy_fixed_ida, phy_addr);
176 return;
177 }
178 }
179}
180
181struct phy_device *fixed_phy_register(unsigned int irq,
182 struct fixed_phy_status *status,
183 int link_gpio,
184 struct device_node *np)
185{
186 struct fixed_mdio_bus *fmb = &platform_fmb;
187 struct phy_device *phy;
188 int phy_addr;
189 int ret;
190
191 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
192 return ERR_PTR(-EPROBE_DEFER);
193
194 /* Get the next available PHY address, up to PHY_MAX_ADDR */
195 phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
196 if (phy_addr < 0)
197 return ERR_PTR(phy_addr);
198
199 ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
200 if (ret < 0) {
201 ida_simple_remove(&phy_fixed_ida, phy_addr);
202 return ERR_PTR(ret);
203 }
204
205 phy = get_phy_device(fmb->mii_bus, phy_addr, false);
206 if (IS_ERR(phy)) {
207 fixed_phy_del(phy_addr);
208 return ERR_PTR(-EINVAL);
209 }
210
211 /* propagate the fixed link values to struct phy_device */
212 phy->link = status->link;
213 if (status->link) {
214 phy->speed = status->speed;
215 phy->duplex = status->duplex;
216 phy->pause = status->pause;
217 phy->asym_pause = status->asym_pause;
218 }
219
220 of_node_get(np);
221 phy->mdio.dev.of_node = np;
222 phy->is_pseudo_fixed_link = true;
223
224 switch (status->speed) {
225 case SPEED_1000:
226 phy->supported = PHY_1000BT_FEATURES;
227 break;
228 case SPEED_100:
229 phy->supported = PHY_100BT_FEATURES;
230 break;
231 case SPEED_10:
232 default:
233 phy->supported = PHY_10BT_FEATURES;
234 }
235
236 ret = phy_device_register(phy);
237 if (ret) {
238 phy_device_free(phy);
239 of_node_put(np);
240 fixed_phy_del(phy_addr);
241 return ERR_PTR(ret);
242 }
243
244 return phy;
245}
246EXPORT_SYMBOL_GPL(fixed_phy_register);
247
248void fixed_phy_unregister(struct phy_device *phy)
249{
250 phy_device_remove(phy);
251 of_node_put(phy->mdio.dev.of_node);
252 fixed_phy_del(phy->mdio.addr);
253}
254EXPORT_SYMBOL_GPL(fixed_phy_unregister);
255
256static int __init fixed_mdio_bus_init(void)
257{
258 struct fixed_mdio_bus *fmb = &platform_fmb;
259 int ret;
260
261 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
262 if (IS_ERR(pdev)) {
263 ret = PTR_ERR(pdev);
264 goto err_pdev;
265 }
266
267 fmb->mii_bus = mdiobus_alloc();
268 if (fmb->mii_bus == NULL) {
269 ret = -ENOMEM;
270 goto err_mdiobus_reg;
271 }
272
273 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
274 fmb->mii_bus->name = "Fixed MDIO Bus";
275 fmb->mii_bus->priv = fmb;
276 fmb->mii_bus->parent = &pdev->dev;
277 fmb->mii_bus->read = &fixed_mdio_read;
278 fmb->mii_bus->write = &fixed_mdio_write;
279
280 ret = mdiobus_register(fmb->mii_bus);
281 if (ret)
282 goto err_mdiobus_alloc;
283
284 return 0;
285
286err_mdiobus_alloc:
287 mdiobus_free(fmb->mii_bus);
288err_mdiobus_reg:
289 platform_device_unregister(pdev);
290err_pdev:
291 return ret;
292}
293module_init(fixed_mdio_bus_init);
294
295static void __exit fixed_mdio_bus_exit(void)
296{
297 struct fixed_mdio_bus *fmb = &platform_fmb;
298 struct fixed_phy *fp, *tmp;
299
300 mdiobus_unregister(fmb->mii_bus);
301 mdiobus_free(fmb->mii_bus);
302 platform_device_unregister(pdev);
303
304 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
305 list_del(&fp->node);
306 kfree(fp);
307 }
308 ida_destroy(&phy_fixed_ida);
309}
310module_exit(fixed_mdio_bus_exit);
311
312MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
313MODULE_AUTHOR("Vitaly Bordug");
314MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
4 *
5 * Author: Vitaly Bordug <vbordug@ru.mvista.com>
6 * Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * Copyright (c) 2006-2007 MontaVista Software, Inc.
9 */
10
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>
20#include <linux/of.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>
26
27#include "swphy.h"
28
29struct fixed_mdio_bus {
30 struct mii_bus *mii_bus;
31 struct list_head phys;
32};
33
34struct fixed_phy {
35 int addr;
36 struct phy_device *phydev;
37 seqcount_t seqcount;
38 struct fixed_phy_status status;
39 bool no_carrier;
40 int (*link_update)(struct net_device *, struct fixed_phy_status *);
41 struct list_head node;
42 struct gpio_desc *link_gpiod;
43};
44
45static struct platform_device *pdev;
46static struct fixed_mdio_bus platform_fmb = {
47 .phys = LIST_HEAD_INIT(platform_fmb.phys),
48};
49
50int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier)
51{
52 struct fixed_mdio_bus *fmb = &platform_fmb;
53 struct phy_device *phydev = dev->phydev;
54 struct fixed_phy *fp;
55
56 if (!phydev || !phydev->mdio.bus)
57 return -EINVAL;
58
59 list_for_each_entry(fp, &fmb->phys, node) {
60 if (fp->addr == phydev->mdio.addr) {
61 fp->no_carrier = !new_carrier;
62 return 0;
63 }
64 }
65 return -EINVAL;
66}
67EXPORT_SYMBOL_GPL(fixed_phy_change_carrier);
68
69static void fixed_phy_update(struct fixed_phy *fp)
70{
71 if (!fp->no_carrier && fp->link_gpiod)
72 fp->status.link = !!gpiod_get_value_cansleep(fp->link_gpiod);
73}
74
75static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
76{
77 struct fixed_mdio_bus *fmb = bus->priv;
78 struct fixed_phy *fp;
79
80 list_for_each_entry(fp, &fmb->phys, node) {
81 if (fp->addr == phy_addr) {
82 struct fixed_phy_status state;
83 int s;
84
85 do {
86 s = read_seqcount_begin(&fp->seqcount);
87 fp->status.link = !fp->no_carrier;
88 /* Issue callback if user registered it. */
89 if (fp->link_update)
90 fp->link_update(fp->phydev->attached_dev,
91 &fp->status);
92 /* Check the GPIO for change in status */
93 fixed_phy_update(fp);
94 state = fp->status;
95 } while (read_seqcount_retry(&fp->seqcount, s));
96
97 return swphy_read_reg(reg_num, &state);
98 }
99 }
100
101 return 0xFFFF;
102}
103
104static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
105 u16 val)
106{
107 return 0;
108}
109
110/*
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.
114 */
115int fixed_phy_set_link_update(struct phy_device *phydev,
116 int (*link_update)(struct net_device *,
117 struct fixed_phy_status *))
118{
119 struct fixed_mdio_bus *fmb = &platform_fmb;
120 struct fixed_phy *fp;
121
122 if (!phydev || !phydev->mdio.bus)
123 return -EINVAL;
124
125 list_for_each_entry(fp, &fmb->phys, node) {
126 if (fp->addr == phydev->mdio.addr) {
127 fp->link_update = link_update;
128 fp->phydev = phydev;
129 return 0;
130 }
131 }
132
133 return -ENOENT;
134}
135EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
136
137static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr,
138 struct fixed_phy_status *status,
139 struct gpio_desc *gpiod)
140{
141 int ret;
142 struct fixed_mdio_bus *fmb = &platform_fmb;
143 struct fixed_phy *fp;
144
145 ret = swphy_validate_state(status);
146 if (ret < 0)
147 return ret;
148
149 fp = kzalloc(sizeof(*fp), GFP_KERNEL);
150 if (!fp)
151 return -ENOMEM;
152
153 seqcount_init(&fp->seqcount);
154
155 if (irq != PHY_POLL)
156 fmb->mii_bus->irq[phy_addr] = irq;
157
158 fp->addr = phy_addr;
159 fp->status = *status;
160 fp->link_gpiod = gpiod;
161
162 fixed_phy_update(fp);
163
164 list_add_tail(&fp->node, &fmb->phys);
165
166 return 0;
167}
168
169int fixed_phy_add(unsigned int irq, int phy_addr,
170 struct fixed_phy_status *status) {
171
172 return fixed_phy_add_gpiod(irq, phy_addr, status, NULL);
173}
174EXPORT_SYMBOL_GPL(fixed_phy_add);
175
176static DEFINE_IDA(phy_fixed_ida);
177
178static void fixed_phy_del(int phy_addr)
179{
180 struct fixed_mdio_bus *fmb = &platform_fmb;
181 struct fixed_phy *fp, *tmp;
182
183 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
184 if (fp->addr == phy_addr) {
185 list_del(&fp->node);
186 if (fp->link_gpiod)
187 gpiod_put(fp->link_gpiod);
188 kfree(fp);
189 ida_simple_remove(&phy_fixed_ida, phy_addr);
190 return;
191 }
192 }
193}
194
195#ifdef CONFIG_OF_GPIO
196static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
197{
198 struct device_node *fixed_link_node;
199 struct gpio_desc *gpiod;
200
201 if (!np)
202 return NULL;
203
204 fixed_link_node = of_get_child_by_name(np, "fixed-link");
205 if (!fixed_link_node)
206 return NULL;
207
208 /*
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.
212 */
213 gpiod = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0,
214 GPIOD_IN, "mdio");
215 of_node_put(fixed_link_node);
216 if (IS_ERR(gpiod)) {
217 if (PTR_ERR(gpiod) == -EPROBE_DEFER)
218 return gpiod;
219
220 if (PTR_ERR(gpiod) != -ENOENT)
221 pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
222 fixed_link_node);
223 gpiod = NULL;
224 }
225
226 return gpiod;
227}
228#else
229static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
230{
231 return NULL;
232}
233#endif
234
235static 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)
239{
240 struct fixed_mdio_bus *fmb = &platform_fmb;
241 struct phy_device *phy;
242 int phy_addr;
243 int ret;
244
245 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
246 return ERR_PTR(-EPROBE_DEFER);
247
248 /* Check if we have a GPIO associated with this fixed phy */
249 if (!gpiod) {
250 gpiod = fixed_phy_get_gpiod(np);
251 if (IS_ERR(gpiod))
252 return ERR_CAST(gpiod);
253 }
254
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);
257 if (phy_addr < 0)
258 return ERR_PTR(phy_addr);
259
260 ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod);
261 if (ret < 0) {
262 ida_simple_remove(&phy_fixed_ida, phy_addr);
263 return ERR_PTR(ret);
264 }
265
266 phy = get_phy_device(fmb->mii_bus, phy_addr, false);
267 if (IS_ERR(phy)) {
268 fixed_phy_del(phy_addr);
269 return ERR_PTR(-EINVAL);
270 }
271
272 /* propagate the fixed link values to struct phy_device */
273 phy->link = status->link;
274 if (status->link) {
275 phy->speed = status->speed;
276 phy->duplex = status->duplex;
277 phy->pause = status->pause;
278 phy->asym_pause = status->asym_pause;
279 }
280
281 of_node_get(np);
282 phy->mdio.dev.of_node = np;
283 phy->is_pseudo_fixed_link = true;
284
285 switch (status->speed) {
286 case SPEED_1000:
287 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
288 phy->supported);
289 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
290 phy->supported);
291 /* fall through */
292 case SPEED_100:
293 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
294 phy->supported);
295 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
296 phy->supported);
297 /* fall through */
298 case SPEED_10:
299 default:
300 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
301 phy->supported);
302 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
303 phy->supported);
304 }
305
306 phy_advertise_supported(phy);
307
308 ret = phy_device_register(phy);
309 if (ret) {
310 phy_device_free(phy);
311 of_node_put(np);
312 fixed_phy_del(phy_addr);
313 return ERR_PTR(ret);
314 }
315
316 return phy;
317}
318
319struct phy_device *fixed_phy_register(unsigned int irq,
320 struct fixed_phy_status *status,
321 struct device_node *np)
322{
323 return __fixed_phy_register(irq, status, np, NULL);
324}
325EXPORT_SYMBOL_GPL(fixed_phy_register);
326
327struct phy_device *
328fixed_phy_register_with_gpiod(unsigned int irq,
329 struct fixed_phy_status *status,
330 struct gpio_desc *gpiod)
331{
332 return __fixed_phy_register(irq, status, NULL, gpiod);
333}
334EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod);
335
336void fixed_phy_unregister(struct phy_device *phy)
337{
338 phy_device_remove(phy);
339 of_node_put(phy->mdio.dev.of_node);
340 fixed_phy_del(phy->mdio.addr);
341}
342EXPORT_SYMBOL_GPL(fixed_phy_unregister);
343
344static int __init fixed_mdio_bus_init(void)
345{
346 struct fixed_mdio_bus *fmb = &platform_fmb;
347 int ret;
348
349 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
350 if (IS_ERR(pdev))
351 return PTR_ERR(pdev);
352
353 fmb->mii_bus = mdiobus_alloc();
354 if (fmb->mii_bus == NULL) {
355 ret = -ENOMEM;
356 goto err_mdiobus_reg;
357 }
358
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;
365
366 ret = mdiobus_register(fmb->mii_bus);
367 if (ret)
368 goto err_mdiobus_alloc;
369
370 return 0;
371
372err_mdiobus_alloc:
373 mdiobus_free(fmb->mii_bus);
374err_mdiobus_reg:
375 platform_device_unregister(pdev);
376 return ret;
377}
378module_init(fixed_mdio_bus_init);
379
380static void __exit fixed_mdio_bus_exit(void)
381{
382 struct fixed_mdio_bus *fmb = &platform_fmb;
383 struct fixed_phy *fp, *tmp;
384
385 mdiobus_unregister(fmb->mii_bus);
386 mdiobus_free(fmb->mii_bus);
387 platform_device_unregister(pdev);
388
389 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
390 list_del(&fp->node);
391 kfree(fp);
392 }
393 ida_destroy(&phy_fixed_ida);
394}
395module_exit(fixed_mdio_bus_exit);
396
397MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
398MODULE_AUTHOR("Vitaly Bordug");
399MODULE_LICENSE("GPL");