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
26 #define MII_REGS_NUM 29
27
28 struct fixed_mdio_bus {
29 int irqs[PHY_MAX_ADDR];
30 struct mii_bus *mii_bus;
31 struct list_head phys;
32 };
33
34 struct fixed_phy {
35 int addr;
36 u16 regs[MII_REGS_NUM];
37 struct phy_device *phydev;
38 struct fixed_phy_status status;
39 int (*link_update)(struct net_device *, struct fixed_phy_status *);
40 struct list_head node;
41 };
42
43 static struct platform_device *pdev;
44 static struct fixed_mdio_bus platform_fmb = {
45 .phys = LIST_HEAD_INIT(platform_fmb.phys),
46 };
47
fixed_phy_update_regs(struct fixed_phy * fp)48 static int fixed_phy_update_regs(struct fixed_phy *fp)
49 {
50 u16 bmsr = BMSR_ANEGCAPABLE;
51 u16 bmcr = 0;
52 u16 lpagb = 0;
53 u16 lpa = 0;
54
55 if (fp->status.duplex) {
56 bmcr |= BMCR_FULLDPLX;
57
58 switch (fp->status.speed) {
59 case 1000:
60 bmsr |= BMSR_ESTATEN;
61 bmcr |= BMCR_SPEED1000;
62 lpagb |= LPA_1000FULL;
63 break;
64 case 100:
65 bmsr |= BMSR_100FULL;
66 bmcr |= BMCR_SPEED100;
67 lpa |= LPA_100FULL;
68 break;
69 case 10:
70 bmsr |= BMSR_10FULL;
71 lpa |= LPA_10FULL;
72 break;
73 default:
74 pr_warn("fixed phy: unknown speed\n");
75 return -EINVAL;
76 }
77 } else {
78 switch (fp->status.speed) {
79 case 1000:
80 bmsr |= BMSR_ESTATEN;
81 bmcr |= BMCR_SPEED1000;
82 lpagb |= LPA_1000HALF;
83 break;
84 case 100:
85 bmsr |= BMSR_100HALF;
86 bmcr |= BMCR_SPEED100;
87 lpa |= LPA_100HALF;
88 break;
89 case 10:
90 bmsr |= BMSR_10HALF;
91 lpa |= LPA_10HALF;
92 break;
93 default:
94 pr_warn("fixed phy: unknown speed\n");
95 return -EINVAL;
96 }
97 }
98
99 if (fp->status.link)
100 bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
101
102 if (fp->status.pause)
103 lpa |= LPA_PAUSE_CAP;
104
105 if (fp->status.asym_pause)
106 lpa |= LPA_PAUSE_ASYM;
107
108 fp->regs[MII_PHYSID1] = 0;
109 fp->regs[MII_PHYSID2] = 0;
110
111 fp->regs[MII_BMSR] = bmsr;
112 fp->regs[MII_BMCR] = bmcr;
113 fp->regs[MII_LPA] = lpa;
114 fp->regs[MII_STAT1000] = lpagb;
115
116 return 0;
117 }
118
fixed_mdio_read(struct mii_bus * bus,int phy_addr,int reg_num)119 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
120 {
121 struct fixed_mdio_bus *fmb = bus->priv;
122 struct fixed_phy *fp;
123
124 if (reg_num >= MII_REGS_NUM)
125 return -1;
126
127 /* We do not support emulating Clause 45 over Clause 22 register reads
128 * return an error instead of bogus data.
129 */
130 switch (reg_num) {
131 case MII_MMD_CTRL:
132 case MII_MMD_DATA:
133 return -1;
134 default:
135 break;
136 }
137
138 list_for_each_entry(fp, &fmb->phys, node) {
139 if (fp->addr == phy_addr) {
140 /* Issue callback if user registered it. */
141 if (fp->link_update) {
142 fp->link_update(fp->phydev->attached_dev,
143 &fp->status);
144 fixed_phy_update_regs(fp);
145 }
146 return fp->regs[reg_num];
147 }
148 }
149
150 return 0xFFFF;
151 }
152
fixed_mdio_write(struct mii_bus * bus,int phy_addr,int reg_num,u16 val)153 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
154 u16 val)
155 {
156 return 0;
157 }
158
159 /*
160 * If something weird is required to be done with link/speed,
161 * network driver is able to assign a function to implement this.
162 * May be useful for PHY's that need to be software-driven.
163 */
fixed_phy_set_link_update(struct phy_device * phydev,int (* link_update)(struct net_device *,struct fixed_phy_status *))164 int fixed_phy_set_link_update(struct phy_device *phydev,
165 int (*link_update)(struct net_device *,
166 struct fixed_phy_status *))
167 {
168 struct fixed_mdio_bus *fmb = &platform_fmb;
169 struct fixed_phy *fp;
170
171 if (!link_update || !phydev || !phydev->bus)
172 return -EINVAL;
173
174 list_for_each_entry(fp, &fmb->phys, node) {
175 if (fp->addr == phydev->addr) {
176 fp->link_update = link_update;
177 fp->phydev = phydev;
178 return 0;
179 }
180 }
181
182 return -ENOENT;
183 }
184 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
185
fixed_phy_add(unsigned int irq,int phy_addr,struct fixed_phy_status * status)186 int fixed_phy_add(unsigned int irq, int phy_addr,
187 struct fixed_phy_status *status)
188 {
189 int ret;
190 struct fixed_mdio_bus *fmb = &platform_fmb;
191 struct fixed_phy *fp;
192
193 fp = kzalloc(sizeof(*fp), GFP_KERNEL);
194 if (!fp)
195 return -ENOMEM;
196
197 memset(fp->regs, 0xFF, sizeof(fp->regs[0]) * MII_REGS_NUM);
198
199 fmb->irqs[phy_addr] = irq;
200
201 fp->addr = phy_addr;
202 fp->status = *status;
203
204 ret = fixed_phy_update_regs(fp);
205 if (ret)
206 goto err_regs;
207
208 list_add_tail(&fp->node, &fmb->phys);
209
210 return 0;
211
212 err_regs:
213 kfree(fp);
214 return ret;
215 }
216 EXPORT_SYMBOL_GPL(fixed_phy_add);
217
fixed_phy_del(int phy_addr)218 void fixed_phy_del(int phy_addr)
219 {
220 struct fixed_mdio_bus *fmb = &platform_fmb;
221 struct fixed_phy *fp, *tmp;
222
223 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
224 if (fp->addr == phy_addr) {
225 list_del(&fp->node);
226 kfree(fp);
227 return;
228 }
229 }
230 }
231 EXPORT_SYMBOL_GPL(fixed_phy_del);
232
233 static int phy_fixed_addr;
234 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
235
fixed_phy_register(unsigned int irq,struct fixed_phy_status * status,struct device_node * np)236 struct phy_device *fixed_phy_register(unsigned int irq,
237 struct fixed_phy_status *status,
238 struct device_node *np)
239 {
240 struct fixed_mdio_bus *fmb = &platform_fmb;
241 struct phy_device *phy;
242 int phy_addr;
243 int ret;
244
245 /* Get the next available PHY address, up to PHY_MAX_ADDR */
246 spin_lock(&phy_fixed_addr_lock);
247 if (phy_fixed_addr == PHY_MAX_ADDR) {
248 spin_unlock(&phy_fixed_addr_lock);
249 return ERR_PTR(-ENOSPC);
250 }
251 phy_addr = phy_fixed_addr++;
252 spin_unlock(&phy_fixed_addr_lock);
253
254 ret = fixed_phy_add(PHY_POLL, phy_addr, status);
255 if (ret < 0)
256 return ERR_PTR(ret);
257
258 phy = get_phy_device(fmb->mii_bus, phy_addr, false);
259 if (!phy || IS_ERR(phy)) {
260 fixed_phy_del(phy_addr);
261 return ERR_PTR(-EINVAL);
262 }
263
264 of_node_get(np);
265 phy->dev.of_node = np;
266
267 ret = phy_device_register(phy);
268 if (ret) {
269 phy_device_free(phy);
270 of_node_put(np);
271 fixed_phy_del(phy_addr);
272 return ERR_PTR(ret);
273 }
274
275 return phy;
276 }
277
fixed_mdio_bus_init(void)278 static int __init fixed_mdio_bus_init(void)
279 {
280 struct fixed_mdio_bus *fmb = &platform_fmb;
281 int ret;
282
283 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
284 if (IS_ERR(pdev)) {
285 ret = PTR_ERR(pdev);
286 goto err_pdev;
287 }
288
289 fmb->mii_bus = mdiobus_alloc();
290 if (fmb->mii_bus == NULL) {
291 ret = -ENOMEM;
292 goto err_mdiobus_reg;
293 }
294
295 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
296 fmb->mii_bus->name = "Fixed MDIO Bus";
297 fmb->mii_bus->priv = fmb;
298 fmb->mii_bus->parent = &pdev->dev;
299 fmb->mii_bus->read = &fixed_mdio_read;
300 fmb->mii_bus->write = &fixed_mdio_write;
301 fmb->mii_bus->irq = fmb->irqs;
302
303 ret = mdiobus_register(fmb->mii_bus);
304 if (ret)
305 goto err_mdiobus_alloc;
306
307 return 0;
308
309 err_mdiobus_alloc:
310 mdiobus_free(fmb->mii_bus);
311 err_mdiobus_reg:
312 platform_device_unregister(pdev);
313 err_pdev:
314 return ret;
315 }
316 module_init(fixed_mdio_bus_init);
317
fixed_mdio_bus_exit(void)318 static void __exit fixed_mdio_bus_exit(void)
319 {
320 struct fixed_mdio_bus *fmb = &platform_fmb;
321 struct fixed_phy *fp, *tmp;
322
323 mdiobus_unregister(fmb->mii_bus);
324 mdiobus_free(fmb->mii_bus);
325 platform_device_unregister(pdev);
326
327 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
328 list_del(&fp->node);
329 kfree(fp);
330 }
331 }
332 module_exit(fixed_mdio_bus_exit);
333
334 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
335 MODULE_AUTHOR("Vitaly Bordug");
336 MODULE_LICENSE("GPL");
337