xref: /openbmc/linux/drivers/net/phy/fixed_phy.c (revision a3bebdce)
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 
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 
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 
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  */
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 (!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 
186 int fixed_phy_update_state(struct phy_device *phydev,
187 			   const struct fixed_phy_status *status,
188 			   const struct fixed_phy_status *changed)
189 {
190 	struct fixed_mdio_bus *fmb = &platform_fmb;
191 	struct fixed_phy *fp;
192 
193 	if (!phydev || !phydev->bus)
194 		return -EINVAL;
195 
196 	list_for_each_entry(fp, &fmb->phys, node) {
197 		if (fp->addr == phydev->addr) {
198 #define _UPD(x) if (changed->x) \
199 	fp->status.x = status->x
200 			_UPD(link);
201 			_UPD(speed);
202 			_UPD(duplex);
203 			_UPD(pause);
204 			_UPD(asym_pause);
205 #undef _UPD
206 			fixed_phy_update_regs(fp);
207 			return 0;
208 		}
209 	}
210 
211 	return -ENOENT;
212 }
213 EXPORT_SYMBOL(fixed_phy_update_state);
214 
215 int fixed_phy_add(unsigned int irq, int phy_addr,
216 		  struct fixed_phy_status *status)
217 {
218 	int ret;
219 	struct fixed_mdio_bus *fmb = &platform_fmb;
220 	struct fixed_phy *fp;
221 
222 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
223 	if (!fp)
224 		return -ENOMEM;
225 
226 	memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
227 
228 	fmb->irqs[phy_addr] = irq;
229 
230 	fp->addr = phy_addr;
231 	fp->status = *status;
232 
233 	ret = fixed_phy_update_regs(fp);
234 	if (ret)
235 		goto err_regs;
236 
237 	list_add_tail(&fp->node, &fmb->phys);
238 
239 	return 0;
240 
241 err_regs:
242 	kfree(fp);
243 	return ret;
244 }
245 EXPORT_SYMBOL_GPL(fixed_phy_add);
246 
247 void fixed_phy_del(int phy_addr)
248 {
249 	struct fixed_mdio_bus *fmb = &platform_fmb;
250 	struct fixed_phy *fp, *tmp;
251 
252 	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
253 		if (fp->addr == phy_addr) {
254 			list_del(&fp->node);
255 			kfree(fp);
256 			return;
257 		}
258 	}
259 }
260 EXPORT_SYMBOL_GPL(fixed_phy_del);
261 
262 static int phy_fixed_addr;
263 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
264 
265 struct phy_device *fixed_phy_register(unsigned int irq,
266 				      struct fixed_phy_status *status,
267 				      struct device_node *np)
268 {
269 	struct fixed_mdio_bus *fmb = &platform_fmb;
270 	struct phy_device *phy;
271 	int phy_addr;
272 	int ret;
273 
274 	/* Get the next available PHY address, up to PHY_MAX_ADDR */
275 	spin_lock(&phy_fixed_addr_lock);
276 	if (phy_fixed_addr == PHY_MAX_ADDR) {
277 		spin_unlock(&phy_fixed_addr_lock);
278 		return ERR_PTR(-ENOSPC);
279 	}
280 	phy_addr = phy_fixed_addr++;
281 	spin_unlock(&phy_fixed_addr_lock);
282 
283 	ret = fixed_phy_add(PHY_POLL, phy_addr, status);
284 	if (ret < 0)
285 		return ERR_PTR(ret);
286 
287 	phy = get_phy_device(fmb->mii_bus, phy_addr, false);
288 	if (!phy || IS_ERR(phy)) {
289 		fixed_phy_del(phy_addr);
290 		return ERR_PTR(-EINVAL);
291 	}
292 
293 	of_node_get(np);
294 	phy->dev.of_node = np;
295 
296 	ret = phy_device_register(phy);
297 	if (ret) {
298 		phy_device_free(phy);
299 		of_node_put(np);
300 		fixed_phy_del(phy_addr);
301 		return ERR_PTR(ret);
302 	}
303 
304 	return phy;
305 }
306 EXPORT_SYMBOL_GPL(fixed_phy_register);
307 
308 static int __init fixed_mdio_bus_init(void)
309 {
310 	struct fixed_mdio_bus *fmb = &platform_fmb;
311 	int ret;
312 
313 	pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
314 	if (IS_ERR(pdev)) {
315 		ret = PTR_ERR(pdev);
316 		goto err_pdev;
317 	}
318 
319 	fmb->mii_bus = mdiobus_alloc();
320 	if (fmb->mii_bus == NULL) {
321 		ret = -ENOMEM;
322 		goto err_mdiobus_reg;
323 	}
324 
325 	snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
326 	fmb->mii_bus->name = "Fixed MDIO Bus";
327 	fmb->mii_bus->priv = fmb;
328 	fmb->mii_bus->parent = &pdev->dev;
329 	fmb->mii_bus->read = &fixed_mdio_read;
330 	fmb->mii_bus->write = &fixed_mdio_write;
331 	fmb->mii_bus->irq = fmb->irqs;
332 
333 	ret = mdiobus_register(fmb->mii_bus);
334 	if (ret)
335 		goto err_mdiobus_alloc;
336 
337 	return 0;
338 
339 err_mdiobus_alloc:
340 	mdiobus_free(fmb->mii_bus);
341 err_mdiobus_reg:
342 	platform_device_unregister(pdev);
343 err_pdev:
344 	return ret;
345 }
346 module_init(fixed_mdio_bus_init);
347 
348 static void __exit fixed_mdio_bus_exit(void)
349 {
350 	struct fixed_mdio_bus *fmb = &platform_fmb;
351 	struct fixed_phy *fp, *tmp;
352 
353 	mdiobus_unregister(fmb->mii_bus);
354 	mdiobus_free(fmb->mii_bus);
355 	platform_device_unregister(pdev);
356 
357 	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
358 		list_del(&fp->node);
359 		kfree(fp);
360 	}
361 }
362 module_exit(fixed_mdio_bus_exit);
363 
364 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
365 MODULE_AUTHOR("Vitaly Bordug");
366 MODULE_LICENSE("GPL");
367