xref: /openbmc/linux/drivers/net/phy/fixed_phy.c (revision 9cfc5c90)
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 
27 #define MII_REGS_NUM 29
28 
29 struct fixed_mdio_bus {
30 	int irqs[PHY_MAX_ADDR];
31 	struct mii_bus *mii_bus;
32 	struct list_head phys;
33 };
34 
35 struct fixed_phy {
36 	int addr;
37 	u16 regs[MII_REGS_NUM];
38 	struct phy_device *phydev;
39 	struct fixed_phy_status status;
40 	int (*link_update)(struct net_device *, struct fixed_phy_status *);
41 	struct list_head node;
42 	int link_gpio;
43 };
44 
45 static struct platform_device *pdev;
46 static struct fixed_mdio_bus platform_fmb = {
47 	.phys = LIST_HEAD_INIT(platform_fmb.phys),
48 };
49 
50 static int fixed_phy_update_regs(struct fixed_phy *fp)
51 {
52 	u16 bmsr = BMSR_ANEGCAPABLE;
53 	u16 bmcr = 0;
54 	u16 lpagb = 0;
55 	u16 lpa = 0;
56 
57 	if (gpio_is_valid(fp->link_gpio))
58 		fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio);
59 
60 	if (fp->status.duplex) {
61 		switch (fp->status.speed) {
62 		case 1000:
63 			bmsr |= BMSR_ESTATEN;
64 			break;
65 		case 100:
66 			bmsr |= BMSR_100FULL;
67 			break;
68 		case 10:
69 			bmsr |= BMSR_10FULL;
70 			break;
71 		default:
72 			break;
73 		}
74 	} else {
75 		switch (fp->status.speed) {
76 		case 1000:
77 			bmsr |= BMSR_ESTATEN;
78 			break;
79 		case 100:
80 			bmsr |= BMSR_100HALF;
81 			break;
82 		case 10:
83 			bmsr |= BMSR_10HALF;
84 			break;
85 		default:
86 			break;
87 		}
88 	}
89 
90 	if (fp->status.link) {
91 		bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
92 
93 		if (fp->status.duplex) {
94 			bmcr |= BMCR_FULLDPLX;
95 
96 			switch (fp->status.speed) {
97 			case 1000:
98 				bmcr |= BMCR_SPEED1000;
99 				lpagb |= LPA_1000FULL;
100 				break;
101 			case 100:
102 				bmcr |= BMCR_SPEED100;
103 				lpa |= LPA_100FULL;
104 				break;
105 			case 10:
106 				lpa |= LPA_10FULL;
107 				break;
108 			default:
109 				pr_warn("fixed phy: unknown speed\n");
110 				return -EINVAL;
111 			}
112 		} else {
113 			switch (fp->status.speed) {
114 			case 1000:
115 				bmcr |= BMCR_SPEED1000;
116 				lpagb |= LPA_1000HALF;
117 				break;
118 			case 100:
119 				bmcr |= BMCR_SPEED100;
120 				lpa |= LPA_100HALF;
121 				break;
122 			case 10:
123 				lpa |= LPA_10HALF;
124 				break;
125 			default:
126 				pr_warn("fixed phy: unknown speed\n");
127 			return -EINVAL;
128 			}
129 		}
130 
131 		if (fp->status.pause)
132 			lpa |= LPA_PAUSE_CAP;
133 
134 		if (fp->status.asym_pause)
135 			lpa |= LPA_PAUSE_ASYM;
136 	}
137 
138 	fp->regs[MII_PHYSID1] = 0;
139 	fp->regs[MII_PHYSID2] = 0;
140 
141 	fp->regs[MII_BMSR] = bmsr;
142 	fp->regs[MII_BMCR] = bmcr;
143 	fp->regs[MII_LPA] = lpa;
144 	fp->regs[MII_STAT1000] = lpagb;
145 
146 	return 0;
147 }
148 
149 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
150 {
151 	struct fixed_mdio_bus *fmb = bus->priv;
152 	struct fixed_phy *fp;
153 
154 	if (reg_num >= MII_REGS_NUM)
155 		return -1;
156 
157 	/* We do not support emulating Clause 45 over Clause 22 register reads
158 	 * return an error instead of bogus data.
159 	 */
160 	switch (reg_num) {
161 	case MII_MMD_CTRL:
162 	case MII_MMD_DATA:
163 		return -1;
164 	default:
165 		break;
166 	}
167 
168 	list_for_each_entry(fp, &fmb->phys, node) {
169 		if (fp->addr == phy_addr) {
170 			/* Issue callback if user registered it. */
171 			if (fp->link_update) {
172 				fp->link_update(fp->phydev->attached_dev,
173 						&fp->status);
174 				fixed_phy_update_regs(fp);
175 			}
176 			return fp->regs[reg_num];
177 		}
178 	}
179 
180 	return 0xFFFF;
181 }
182 
183 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
184 			    u16 val)
185 {
186 	return 0;
187 }
188 
189 /*
190  * If something weird is required to be done with link/speed,
191  * network driver is able to assign a function to implement this.
192  * May be useful for PHY's that need to be software-driven.
193  */
194 int fixed_phy_set_link_update(struct phy_device *phydev,
195 			      int (*link_update)(struct net_device *,
196 						 struct fixed_phy_status *))
197 {
198 	struct fixed_mdio_bus *fmb = &platform_fmb;
199 	struct fixed_phy *fp;
200 
201 	if (!phydev || !phydev->bus)
202 		return -EINVAL;
203 
204 	list_for_each_entry(fp, &fmb->phys, node) {
205 		if (fp->addr == phydev->addr) {
206 			fp->link_update = link_update;
207 			fp->phydev = phydev;
208 			return 0;
209 		}
210 	}
211 
212 	return -ENOENT;
213 }
214 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
215 
216 int fixed_phy_update_state(struct phy_device *phydev,
217 			   const struct fixed_phy_status *status,
218 			   const struct fixed_phy_status *changed)
219 {
220 	struct fixed_mdio_bus *fmb = &platform_fmb;
221 	struct fixed_phy *fp;
222 
223 	if (!phydev || phydev->bus != fmb->mii_bus)
224 		return -EINVAL;
225 
226 	list_for_each_entry(fp, &fmb->phys, node) {
227 		if (fp->addr == phydev->addr) {
228 #define _UPD(x) if (changed->x) \
229 	fp->status.x = status->x
230 			_UPD(link);
231 			_UPD(speed);
232 			_UPD(duplex);
233 			_UPD(pause);
234 			_UPD(asym_pause);
235 #undef _UPD
236 			fixed_phy_update_regs(fp);
237 			return 0;
238 		}
239 	}
240 
241 	return -ENOENT;
242 }
243 EXPORT_SYMBOL(fixed_phy_update_state);
244 
245 int fixed_phy_add(unsigned int irq, int phy_addr,
246 		  struct fixed_phy_status *status,
247 		  int link_gpio)
248 {
249 	int ret;
250 	struct fixed_mdio_bus *fmb = &platform_fmb;
251 	struct fixed_phy *fp;
252 
253 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
254 	if (!fp)
255 		return -ENOMEM;
256 
257 	memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);
258 
259 	fmb->irqs[phy_addr] = irq;
260 
261 	fp->addr = phy_addr;
262 	fp->status = *status;
263 	fp->link_gpio = link_gpio;
264 
265 	if (gpio_is_valid(fp->link_gpio)) {
266 		ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN,
267 				       "fixed-link-gpio-link");
268 		if (ret)
269 			goto err_regs;
270 	}
271 
272 	ret = fixed_phy_update_regs(fp);
273 	if (ret)
274 		goto err_gpio;
275 
276 	list_add_tail(&fp->node, &fmb->phys);
277 
278 	return 0;
279 
280 err_gpio:
281 	if (gpio_is_valid(fp->link_gpio))
282 		gpio_free(fp->link_gpio);
283 err_regs:
284 	kfree(fp);
285 	return ret;
286 }
287 EXPORT_SYMBOL_GPL(fixed_phy_add);
288 
289 void fixed_phy_del(int phy_addr)
290 {
291 	struct fixed_mdio_bus *fmb = &platform_fmb;
292 	struct fixed_phy *fp, *tmp;
293 
294 	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
295 		if (fp->addr == phy_addr) {
296 			list_del(&fp->node);
297 			if (gpio_is_valid(fp->link_gpio))
298 				gpio_free(fp->link_gpio);
299 			kfree(fp);
300 			return;
301 		}
302 	}
303 }
304 EXPORT_SYMBOL_GPL(fixed_phy_del);
305 
306 static int phy_fixed_addr;
307 static DEFINE_SPINLOCK(phy_fixed_addr_lock);
308 
309 struct phy_device *fixed_phy_register(unsigned int irq,
310 				      struct fixed_phy_status *status,
311 				      int link_gpio,
312 				      struct device_node *np)
313 {
314 	struct fixed_mdio_bus *fmb = &platform_fmb;
315 	struct phy_device *phy;
316 	int phy_addr;
317 	int ret;
318 
319 	/* Get the next available PHY address, up to PHY_MAX_ADDR */
320 	spin_lock(&phy_fixed_addr_lock);
321 	if (phy_fixed_addr == PHY_MAX_ADDR) {
322 		spin_unlock(&phy_fixed_addr_lock);
323 		return ERR_PTR(-ENOSPC);
324 	}
325 	phy_addr = phy_fixed_addr++;
326 	spin_unlock(&phy_fixed_addr_lock);
327 
328 	ret = fixed_phy_add(irq, phy_addr, status, link_gpio);
329 	if (ret < 0)
330 		return ERR_PTR(ret);
331 
332 	phy = get_phy_device(fmb->mii_bus, phy_addr, false);
333 	if (!phy || IS_ERR(phy)) {
334 		fixed_phy_del(phy_addr);
335 		return ERR_PTR(-EINVAL);
336 	}
337 
338 	/* propagate the fixed link values to struct phy_device */
339 	phy->link = status->link;
340 	if (status->link) {
341 		phy->speed = status->speed;
342 		phy->duplex = status->duplex;
343 		phy->pause = status->pause;
344 		phy->asym_pause = status->asym_pause;
345 	}
346 
347 	of_node_get(np);
348 	phy->dev.of_node = np;
349 	phy->is_pseudo_fixed_link = true;
350 
351 	switch (status->speed) {
352 	case SPEED_1000:
353 		phy->supported = PHY_1000BT_FEATURES;
354 		break;
355 	case SPEED_100:
356 		phy->supported = PHY_100BT_FEATURES;
357 		break;
358 	case SPEED_10:
359 	default:
360 		phy->supported = PHY_10BT_FEATURES;
361 	}
362 
363 	ret = phy_device_register(phy);
364 	if (ret) {
365 		phy_device_free(phy);
366 		of_node_put(np);
367 		fixed_phy_del(phy_addr);
368 		return ERR_PTR(ret);
369 	}
370 
371 	return phy;
372 }
373 EXPORT_SYMBOL_GPL(fixed_phy_register);
374 
375 static int __init fixed_mdio_bus_init(void)
376 {
377 	struct fixed_mdio_bus *fmb = &platform_fmb;
378 	int ret;
379 
380 	pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
381 	if (IS_ERR(pdev)) {
382 		ret = PTR_ERR(pdev);
383 		goto err_pdev;
384 	}
385 
386 	fmb->mii_bus = mdiobus_alloc();
387 	if (fmb->mii_bus == NULL) {
388 		ret = -ENOMEM;
389 		goto err_mdiobus_reg;
390 	}
391 
392 	snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
393 	fmb->mii_bus->name = "Fixed MDIO Bus";
394 	fmb->mii_bus->priv = fmb;
395 	fmb->mii_bus->parent = &pdev->dev;
396 	fmb->mii_bus->read = &fixed_mdio_read;
397 	fmb->mii_bus->write = &fixed_mdio_write;
398 	fmb->mii_bus->irq = fmb->irqs;
399 
400 	ret = mdiobus_register(fmb->mii_bus);
401 	if (ret)
402 		goto err_mdiobus_alloc;
403 
404 	return 0;
405 
406 err_mdiobus_alloc:
407 	mdiobus_free(fmb->mii_bus);
408 err_mdiobus_reg:
409 	platform_device_unregister(pdev);
410 err_pdev:
411 	return ret;
412 }
413 module_init(fixed_mdio_bus_init);
414 
415 static void __exit fixed_mdio_bus_exit(void)
416 {
417 	struct fixed_mdio_bus *fmb = &platform_fmb;
418 	struct fixed_phy *fp, *tmp;
419 
420 	mdiobus_unregister(fmb->mii_bus);
421 	mdiobus_free(fmb->mii_bus);
422 	platform_device_unregister(pdev);
423 
424 	list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
425 		list_del(&fp->node);
426 		kfree(fp);
427 	}
428 }
429 module_exit(fixed_mdio_bus_exit);
430 
431 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
432 MODULE_AUTHOR("Vitaly Bordug");
433 MODULE_LICENSE("GPL");
434