1 /*
2  * Freescale PowerQUICC Ethernet Driver -- MIIM bus implementation
3  * Provides Bus interface for MIIM regs
4  *
5  * Author: Andy Fleming <afleming@freescale.com>
6  * Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
7  *
8  * Copyright 2002-2004, 2008-2009 Freescale Semiconductor, Inc.
9  *
10  * Based on gianfar_mii.c and ucc_geth_mii.c (Li Yang, Kim Phillips)
11  *
12  * This program is free software; you can redistribute  it and/or modify it
13  * under  the terms of  the GNU General  Public License as published by the
14  * Free Software Foundation;  either version 2 of the  License, or (at your
15  * option) any later version.
16  *
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/unistd.h>
23 #include <linux/slab.h>
24 #include <linux/interrupt.h>
25 #include <linux/init.h>
26 #include <linux/delay.h>
27 #include <linux/netdevice.h>
28 #include <linux/etherdevice.h>
29 #include <linux/skbuff.h>
30 #include <linux/spinlock.h>
31 #include <linux/mm.h>
32 #include <linux/module.h>
33 #include <linux/platform_device.h>
34 #include <linux/crc32.h>
35 #include <linux/mii.h>
36 #include <linux/phy.h>
37 #include <linux/of.h>
38 #include <linux/of_address.h>
39 #include <linux/of_mdio.h>
40 #include <linux/of_platform.h>
41 
42 #include <asm/io.h>
43 #include <asm/irq.h>
44 #include <asm/uaccess.h>
45 #include <asm/ucc.h>
46 
47 #include "gianfar.h"
48 #include "fsl_pq_mdio.h"
49 
50 struct fsl_pq_mdio_priv {
51 	void __iomem *map;
52 	struct fsl_pq_mdio __iomem *regs;
53 };
54 
55 /*
56  * Write value to the PHY at mii_id at register regnum,
57  * on the bus attached to the local interface, which may be different from the
58  * generic mdio bus (tied to a single interface), waiting until the write is
59  * done before returning. This is helpful in programming interfaces like
60  * the TBI which control interfaces like onchip SERDES and are always tied to
61  * the local mdio pins, which may not be the same as system mdio bus, used for
62  * controlling the external PHYs, for example.
63  */
fsl_pq_local_mdio_write(struct fsl_pq_mdio __iomem * regs,int mii_id,int regnum,u16 value)64 int fsl_pq_local_mdio_write(struct fsl_pq_mdio __iomem *regs, int mii_id,
65 		int regnum, u16 value)
66 {
67 	/* Set the PHY address and the register address we want to write */
68 	out_be32(&regs->miimadd, (mii_id << 8) | regnum);
69 
70 	/* Write out the value we want */
71 	out_be32(&regs->miimcon, value);
72 
73 	/* Wait for the transaction to finish */
74 	while (in_be32(&regs->miimind) & MIIMIND_BUSY)
75 		cpu_relax();
76 
77 	return 0;
78 }
79 
80 /*
81  * Read the bus for PHY at addr mii_id, register regnum, and
82  * return the value.  Clears miimcom first.  All PHY operation
83  * done on the bus attached to the local interface,
84  * which may be different from the generic mdio bus
85  * This is helpful in programming interfaces like
86  * the TBI which, in turn, control interfaces like onchip SERDES
87  * and are always tied to the local mdio pins, which may not be the
88  * same as system mdio bus, used for controlling the external PHYs, for eg.
89  */
fsl_pq_local_mdio_read(struct fsl_pq_mdio __iomem * regs,int mii_id,int regnum)90 int fsl_pq_local_mdio_read(struct fsl_pq_mdio __iomem *regs,
91 		int mii_id, int regnum)
92 {
93 	u16 value;
94 
95 	/* Set the PHY address and the register address we want to read */
96 	out_be32(&regs->miimadd, (mii_id << 8) | regnum);
97 
98 	/* Clear miimcom, and then initiate a read */
99 	out_be32(&regs->miimcom, 0);
100 	out_be32(&regs->miimcom, MII_READ_COMMAND);
101 
102 	/* Wait for the transaction to finish */
103 	while (in_be32(&regs->miimind) & (MIIMIND_NOTVALID | MIIMIND_BUSY))
104 		cpu_relax();
105 
106 	/* Grab the value of the register from miimstat */
107 	value = in_be32(&regs->miimstat);
108 
109 	return value;
110 }
111 
fsl_pq_mdio_get_regs(struct mii_bus * bus)112 static struct fsl_pq_mdio __iomem *fsl_pq_mdio_get_regs(struct mii_bus *bus)
113 {
114 	struct fsl_pq_mdio_priv *priv = bus->priv;
115 
116 	return priv->regs;
117 }
118 
119 /*
120  * Write value to the PHY at mii_id at register regnum,
121  * on the bus, waiting until the write is done before returning.
122  */
fsl_pq_mdio_write(struct mii_bus * bus,int mii_id,int regnum,u16 value)123 int fsl_pq_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 value)
124 {
125 	struct fsl_pq_mdio __iomem *regs = fsl_pq_mdio_get_regs(bus);
126 
127 	/* Write to the local MII regs */
128 	return fsl_pq_local_mdio_write(regs, mii_id, regnum, value);
129 }
130 
131 /*
132  * Read the bus for PHY at addr mii_id, register regnum, and
133  * return the value.  Clears miimcom first.
134  */
fsl_pq_mdio_read(struct mii_bus * bus,int mii_id,int regnum)135 int fsl_pq_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
136 {
137 	struct fsl_pq_mdio __iomem *regs = fsl_pq_mdio_get_regs(bus);
138 
139 	/* Read the local MII regs */
140 	return fsl_pq_local_mdio_read(regs, mii_id, regnum);
141 }
142 
143 /* Reset the MIIM registers, and wait for the bus to free */
fsl_pq_mdio_reset(struct mii_bus * bus)144 static int fsl_pq_mdio_reset(struct mii_bus *bus)
145 {
146 	struct fsl_pq_mdio __iomem *regs = fsl_pq_mdio_get_regs(bus);
147 	int timeout = PHY_INIT_TIMEOUT;
148 
149 	mutex_lock(&bus->mdio_lock);
150 
151 	/* Reset the management interface */
152 	out_be32(&regs->miimcfg, MIIMCFG_RESET);
153 
154 	/* Setup the MII Mgmt clock speed */
155 	out_be32(&regs->miimcfg, MIIMCFG_INIT_VALUE);
156 
157 	/* Wait until the bus is free */
158 	while ((in_be32(&regs->miimind) & MIIMIND_BUSY) && timeout--)
159 		cpu_relax();
160 
161 	mutex_unlock(&bus->mdio_lock);
162 
163 	if (timeout < 0) {
164 		printk(KERN_ERR "%s: The MII Bus is stuck!\n",
165 				bus->name);
166 		return -EBUSY;
167 	}
168 
169 	return 0;
170 }
171 
fsl_pq_mdio_bus_name(char * name,struct device_node * np)172 void fsl_pq_mdio_bus_name(char *name, struct device_node *np)
173 {
174 	const u32 *addr;
175 	u64 taddr = OF_BAD_ADDR;
176 
177 	addr = of_get_address(np, 0, NULL, NULL);
178 	if (addr)
179 		taddr = of_translate_address(np, addr);
180 
181 	snprintf(name, MII_BUS_ID_SIZE, "%s@%llx", np->name,
182 		(unsigned long long)taddr);
183 }
184 EXPORT_SYMBOL_GPL(fsl_pq_mdio_bus_name);
185 
186 /* Scan the bus in reverse, looking for an empty spot */
fsl_pq_mdio_find_free(struct mii_bus * new_bus)187 static int fsl_pq_mdio_find_free(struct mii_bus *new_bus)
188 {
189 	int i;
190 
191 	for (i = PHY_MAX_ADDR; i > 0; i--) {
192 		u32 phy_id;
193 
194 		if (get_phy_id(new_bus, i, &phy_id))
195 			return -1;
196 
197 		if (phy_id == 0xffffffff)
198 			break;
199 	}
200 
201 	return i;
202 }
203 
204 
205 #if defined(CONFIG_GIANFAR) || defined(CONFIG_GIANFAR_MODULE)
get_gfar_tbipa(struct fsl_pq_mdio __iomem * regs,struct device_node * np)206 static u32 __iomem *get_gfar_tbipa(struct fsl_pq_mdio __iomem *regs, struct device_node *np)
207 {
208 	struct gfar __iomem *enet_regs;
209 
210 	/*
211 	 * This is mildly evil, but so is our hardware for doing this.
212 	 * Also, we have to cast back to struct gfar because of
213 	 * definition weirdness done in gianfar.h.
214 	 */
215 	if(of_device_is_compatible(np, "fsl,gianfar-mdio") ||
216 		of_device_is_compatible(np, "fsl,gianfar-tbi") ||
217 		of_device_is_compatible(np, "gianfar")) {
218 		enet_regs = (struct gfar __iomem *)regs;
219 		return &enet_regs->tbipa;
220 	} else if (of_device_is_compatible(np, "fsl,etsec2-mdio") ||
221 			of_device_is_compatible(np, "fsl,etsec2-tbi")) {
222 		return of_iomap(np, 1);
223 	} else
224 		return NULL;
225 }
226 #endif
227 
228 
229 #if defined(CONFIG_UCC_GETH) || defined(CONFIG_UCC_GETH_MODULE)
get_ucc_id_for_range(u64 start,u64 end,u32 * ucc_id)230 static int get_ucc_id_for_range(u64 start, u64 end, u32 *ucc_id)
231 {
232 	struct device_node *np = NULL;
233 	int err = 0;
234 
235 	for_each_compatible_node(np, NULL, "ucc_geth") {
236 		struct resource tempres;
237 
238 		err = of_address_to_resource(np, 0, &tempres);
239 		if (err)
240 			continue;
241 
242 		/* if our mdio regs fall within this UCC regs range */
243 		if ((start >= tempres.start) && (end <= tempres.end)) {
244 			/* Find the id of the UCC */
245 			const u32 *id;
246 
247 			id = of_get_property(np, "cell-index", NULL);
248 			if (!id) {
249 				id = of_get_property(np, "device-id", NULL);
250 				if (!id)
251 					continue;
252 			}
253 
254 			*ucc_id = *id;
255 
256 			return 0;
257 		}
258 	}
259 
260 	if (err)
261 		return err;
262 	else
263 		return -EINVAL;
264 }
265 #endif
266 
267 
fsl_pq_mdio_probe(struct platform_device * ofdev)268 static int fsl_pq_mdio_probe(struct platform_device *ofdev)
269 {
270 	struct device_node *np = ofdev->dev.of_node;
271 	struct device_node *tbi;
272 	struct fsl_pq_mdio_priv *priv;
273 	struct fsl_pq_mdio __iomem *regs = NULL;
274 	void __iomem *map;
275 	u32 __iomem *tbipa;
276 	struct mii_bus *new_bus;
277 	int tbiaddr = -1;
278 	const u32 *addrp;
279 	u64 addr = 0, size = 0;
280 	int err;
281 
282 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
283 	if (!priv)
284 		return -ENOMEM;
285 
286 	new_bus = mdiobus_alloc();
287 	if (!new_bus) {
288 		err = -ENOMEM;
289 		goto err_free_priv;
290 	}
291 
292 	new_bus->name = "Freescale PowerQUICC MII Bus",
293 	new_bus->read = &fsl_pq_mdio_read,
294 	new_bus->write = &fsl_pq_mdio_write,
295 	new_bus->reset = &fsl_pq_mdio_reset,
296 	new_bus->priv = priv;
297 	fsl_pq_mdio_bus_name(new_bus->id, np);
298 
299 	addrp = of_get_address(np, 0, &size, NULL);
300 	if (!addrp) {
301 		err = -EINVAL;
302 		goto err_free_bus;
303 	}
304 
305 	/* Set the PHY base address */
306 	addr = of_translate_address(np, addrp);
307 	if (addr == OF_BAD_ADDR) {
308 		err = -EINVAL;
309 		goto err_free_bus;
310 	}
311 
312 	map = ioremap(addr, size);
313 	if (!map) {
314 		err = -ENOMEM;
315 		goto err_free_bus;
316 	}
317 	priv->map = map;
318 
319 	if (of_device_is_compatible(np, "fsl,gianfar-mdio") ||
320 			of_device_is_compatible(np, "fsl,gianfar-tbi") ||
321 			of_device_is_compatible(np, "fsl,ucc-mdio") ||
322 			of_device_is_compatible(np, "ucc_geth_phy"))
323 		map -= offsetof(struct fsl_pq_mdio, miimcfg);
324 	regs = map;
325 	priv->regs = regs;
326 
327 	new_bus->irq = kcalloc(PHY_MAX_ADDR, sizeof(int), GFP_KERNEL);
328 
329 	if (NULL == new_bus->irq) {
330 		err = -ENOMEM;
331 		goto err_unmap_regs;
332 	}
333 
334 	new_bus->parent = &ofdev->dev;
335 	dev_set_drvdata(&ofdev->dev, new_bus);
336 
337 	if (of_device_is_compatible(np, "fsl,gianfar-mdio") ||
338 			of_device_is_compatible(np, "fsl,gianfar-tbi") ||
339 			of_device_is_compatible(np, "fsl,etsec2-mdio") ||
340 			of_device_is_compatible(np, "fsl,etsec2-tbi") ||
341 			of_device_is_compatible(np, "gianfar")) {
342 #if defined(CONFIG_GIANFAR) || defined(CONFIG_GIANFAR_MODULE)
343 		tbipa = get_gfar_tbipa(regs, np);
344 		if (!tbipa) {
345 			err = -EINVAL;
346 			goto err_free_irqs;
347 		}
348 #else
349 		err = -ENODEV;
350 		goto err_free_irqs;
351 #endif
352 	} else if (of_device_is_compatible(np, "fsl,ucc-mdio") ||
353 			of_device_is_compatible(np, "ucc_geth_phy")) {
354 #if defined(CONFIG_UCC_GETH) || defined(CONFIG_UCC_GETH_MODULE)
355 		u32 id;
356 		static u32 mii_mng_master;
357 
358 		tbipa = &regs->utbipar;
359 
360 		if ((err = get_ucc_id_for_range(addr, addr + size, &id)))
361 			goto err_free_irqs;
362 
363 		if (!mii_mng_master) {
364 			mii_mng_master = id;
365 			ucc_set_qe_mux_mii_mng(id - 1);
366 		}
367 #else
368 		err = -ENODEV;
369 		goto err_free_irqs;
370 #endif
371 	} else {
372 		err = -ENODEV;
373 		goto err_free_irqs;
374 	}
375 
376 	for_each_child_of_node(np, tbi) {
377 		if (!strncmp(tbi->type, "tbi-phy", 8))
378 			break;
379 	}
380 
381 	if (tbi) {
382 		const u32 *prop = of_get_property(tbi, "reg", NULL);
383 
384 		if (prop)
385 			tbiaddr = *prop;
386 	}
387 
388 	if (tbiaddr == -1) {
389 		out_be32(tbipa, 0);
390 
391 		tbiaddr = fsl_pq_mdio_find_free(new_bus);
392 	}
393 
394 	/*
395 	 * We define TBIPA at 0 to be illegal, opting to fail for boards that
396 	 * have PHYs at 1-31, rather than change tbipa and rescan.
397 	 */
398 	if (tbiaddr == 0) {
399 		err = -EBUSY;
400 
401 		goto err_free_irqs;
402 	}
403 
404 	out_be32(tbipa, tbiaddr);
405 
406 	err = of_mdiobus_register(new_bus, np);
407 	if (err) {
408 		printk (KERN_ERR "%s: Cannot register as MDIO bus\n",
409 				new_bus->name);
410 		goto err_free_irqs;
411 	}
412 
413 	return 0;
414 
415 err_free_irqs:
416 	kfree(new_bus->irq);
417 err_unmap_regs:
418 	iounmap(priv->map);
419 err_free_bus:
420 	kfree(new_bus);
421 err_free_priv:
422 	kfree(priv);
423 	return err;
424 }
425 
426 
fsl_pq_mdio_remove(struct platform_device * ofdev)427 static int fsl_pq_mdio_remove(struct platform_device *ofdev)
428 {
429 	struct device *device = &ofdev->dev;
430 	struct mii_bus *bus = dev_get_drvdata(device);
431 	struct fsl_pq_mdio_priv *priv = bus->priv;
432 
433 	mdiobus_unregister(bus);
434 
435 	dev_set_drvdata(device, NULL);
436 
437 	iounmap(priv->map);
438 	bus->priv = NULL;
439 	mdiobus_free(bus);
440 	kfree(priv);
441 
442 	return 0;
443 }
444 
445 static struct of_device_id fsl_pq_mdio_match[] = {
446 	{
447 		.type = "mdio",
448 		.compatible = "ucc_geth_phy",
449 	},
450 	{
451 		.type = "mdio",
452 		.compatible = "gianfar",
453 	},
454 	{
455 		.compatible = "fsl,ucc-mdio",
456 	},
457 	{
458 		.compatible = "fsl,gianfar-tbi",
459 	},
460 	{
461 		.compatible = "fsl,gianfar-mdio",
462 	},
463 	{
464 		.compatible = "fsl,etsec2-tbi",
465 	},
466 	{
467 		.compatible = "fsl,etsec2-mdio",
468 	},
469 	{},
470 };
471 MODULE_DEVICE_TABLE(of, fsl_pq_mdio_match);
472 
473 static struct platform_driver fsl_pq_mdio_driver = {
474 	.driver = {
475 		.name = "fsl-pq_mdio",
476 		.owner = THIS_MODULE,
477 		.of_match_table = fsl_pq_mdio_match,
478 	},
479 	.probe = fsl_pq_mdio_probe,
480 	.remove = fsl_pq_mdio_remove,
481 };
482 
fsl_pq_mdio_init(void)483 int __init fsl_pq_mdio_init(void)
484 {
485 	return platform_driver_register(&fsl_pq_mdio_driver);
486 }
487 module_init(fsl_pq_mdio_init);
488 
fsl_pq_mdio_exit(void)489 void fsl_pq_mdio_exit(void)
490 {
491 	platform_driver_unregister(&fsl_pq_mdio_driver);
492 }
493 module_exit(fsl_pq_mdio_exit);
494 MODULE_LICENSE("GPL");
495