xref: /openbmc/u-boot/drivers/net/phy/miiphybb.c (revision 62a05573)
1 /*
2  * (C) Copyright 2009 Industrie Dial Face S.p.A.
3  * Luigi 'Comio' Mantellini <luigi.mantellini@idf-hit.com>
4  *
5  * (C) Copyright 2001
6  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
7  *
8  * See file CREDITS for list of people who contributed to this
9  * project.
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of
14  * the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
24  * MA 02111-1307 USA
25  */
26 
27 /*
28  * This provides a bit-banged interface to the ethernet MII management
29  * channel.
30  */
31 
32 #include <common.h>
33 #include <ioports.h>
34 #include <ppc_asm.tmpl>
35 #include <miiphy.h>
36 
37 #define BB_MII_RELOCATE(v,off) (v += (v?off:0))
38 
39 DECLARE_GLOBAL_DATA_PTR;
40 
41 #ifndef CONFIG_BITBANGMII_MULTI
42 
43 /*
44  * If CONFIG_BITBANGMII_MULTI is not defined we use a
45  * compatibility layer with the previous miiphybb implementation
46  * based on macros usage.
47  *
48  */
49 static int bb_mii_init_wrap(struct bb_miiphy_bus *bus)
50 {
51 #ifdef MII_INIT
52 	MII_INIT;
53 #endif
54 	return 0;
55 }
56 
57 static int bb_mdio_active_wrap(struct bb_miiphy_bus *bus)
58 {
59 #ifdef MDIO_DECLARE
60 	MDIO_DECLARE;
61 #endif
62 	MDIO_ACTIVE;
63 	return 0;
64 }
65 
66 static int bb_mdio_tristate_wrap(struct bb_miiphy_bus *bus)
67 {
68 #ifdef MDIO_DECLARE
69 	MDIO_DECLARE;
70 #endif
71 	MDIO_TRISTATE;
72 	return 0;
73 }
74 
75 static int bb_set_mdio_wrap(struct bb_miiphy_bus *bus, int v)
76 {
77 #ifdef MDIO_DECLARE
78 	MDIO_DECLARE;
79 #endif
80 	MDIO(v);
81 	return 0;
82 }
83 
84 static int bb_get_mdio_wrap(struct bb_miiphy_bus *bus, int *v)
85 {
86 #ifdef MDIO_DECLARE
87 	MDIO_DECLARE;
88 #endif
89 	*v = MDIO_READ;
90 	return 0;
91 }
92 
93 static int bb_set_mdc_wrap(struct bb_miiphy_bus *bus, int v)
94 {
95 #ifdef MDC_DECLARE
96 	MDC_DECLARE;
97 #endif
98 	MDC(v);
99 	return 0;
100 }
101 
102 static int bb_delay_wrap(struct bb_miiphy_bus *bus)
103 {
104 	MIIDELAY;
105 	return 0;
106 }
107 
108 struct bb_miiphy_bus bb_miiphy_buses[] = {
109 	{
110 		.name = BB_MII_DEVNAME,
111 		.init = bb_mii_init_wrap,
112 		.mdio_active = bb_mdio_active_wrap,
113 		.mdio_tristate = bb_mdio_tristate_wrap,
114 		.set_mdio = bb_set_mdio_wrap,
115 		.get_mdio = bb_get_mdio_wrap,
116 		.set_mdc = bb_set_mdc_wrap,
117 		.delay = bb_delay_wrap,
118 	}
119 };
120 
121 int bb_miiphy_buses_num = sizeof(bb_miiphy_buses) /
122 			  sizeof(bb_miiphy_buses[0]);
123 #endif
124 
125 void bb_miiphy_init(void)
126 {
127 	int i;
128 
129 	for (i = 0; i < bb_miiphy_buses_num; i++) {
130 #if !defined(CONFIG_RELOC_FIXUP_WORKS)
131 		/* Relocate the hook pointers*/
132 		BB_MII_RELOCATE(bb_miiphy_buses[i].init, gd->reloc_off);
133 		BB_MII_RELOCATE(bb_miiphy_buses[i].mdio_active, gd->reloc_off);
134 		BB_MII_RELOCATE(bb_miiphy_buses[i].mdio_tristate, gd->reloc_off);
135 		BB_MII_RELOCATE(bb_miiphy_buses[i].set_mdio, gd->reloc_off);
136 		BB_MII_RELOCATE(bb_miiphy_buses[i].get_mdio, gd->reloc_off);
137 		BB_MII_RELOCATE(bb_miiphy_buses[i].set_mdc, gd->reloc_off);
138 		BB_MII_RELOCATE(bb_miiphy_buses[i].delay, gd->reloc_off);
139 #endif
140 		if (bb_miiphy_buses[i].init != NULL) {
141 			bb_miiphy_buses[i].init(&bb_miiphy_buses[i]);
142 		}
143 	}
144 }
145 
146 static inline struct bb_miiphy_bus *bb_miiphy_getbus(const char *devname)
147 {
148 #ifdef CONFIG_BITBANGMII_MULTI
149 	int i;
150 
151 	/* Search the correct bus */
152 	for (i = 0; i < bb_miiphy_buses_num; i++) {
153 		if (!strcmp(bb_miiphy_buses[i].name, devname)) {
154 			return &bb_miiphy_buses[i];
155 		}
156 	}
157 	return NULL;
158 #else
159 	/* We have just one bitbanging bus */
160 	return &bb_miiphy_buses[0];
161 #endif
162 }
163 
164 /*****************************************************************************
165  *
166  * Utility to send the preamble, address, and register (common to read
167  * and write).
168  */
169 static void miiphy_pre(struct bb_miiphy_bus *bus, char read,
170 		       unsigned char addr, unsigned char reg)
171 {
172 	int j;
173 
174 	/*
175 	 * Send a 32 bit preamble ('1's) with an extra '1' bit for good measure.
176 	 * The IEEE spec says this is a PHY optional requirement.  The AMD
177 	 * 79C874 requires one after power up and one after a MII communications
178 	 * error.  This means that we are doing more preambles than we need,
179 	 * but it is safer and will be much more robust.
180 	 */
181 
182 	bus->mdio_active(bus);
183 	bus->set_mdio(bus, 1);
184 	for (j = 0; j < 32; j++) {
185 		bus->set_mdc(bus, 0);
186 		bus->delay(bus);
187 		bus->set_mdc(bus, 1);
188 		bus->delay(bus);
189 	}
190 
191 	/* send the start bit (01) and the read opcode (10) or write (10) */
192 	bus->set_mdc(bus, 0);
193 	bus->set_mdio(bus, 0);
194 	bus->delay(bus);
195 	bus->set_mdc(bus, 1);
196 	bus->delay(bus);
197 	bus->set_mdc(bus, 0);
198 	bus->set_mdio(bus, 1);
199 	bus->delay(bus);
200 	bus->set_mdc(bus, 1);
201 	bus->delay(bus);
202 	bus->set_mdc(bus, 0);
203 	bus->set_mdio(bus, read);
204 	bus->delay(bus);
205 	bus->set_mdc(bus, 1);
206 	bus->delay(bus);
207 	bus->set_mdc(bus, 0);
208 	bus->set_mdio(bus, !read);
209 	bus->delay(bus);
210 	bus->set_mdc(bus, 1);
211 	bus->delay(bus);
212 
213 	/* send the PHY address */
214 	for (j = 0; j < 5; j++) {
215 		bus->set_mdc(bus, 0);
216 		if ((addr & 0x10) == 0) {
217 			bus->set_mdio(bus, 0);
218 		} else {
219 			bus->set_mdio(bus, 1);
220 		}
221 		bus->delay(bus);
222 		bus->set_mdc(bus, 1);
223 		bus->delay(bus);
224 		addr <<= 1;
225 	}
226 
227 	/* send the register address */
228 	for (j = 0; j < 5; j++) {
229 		bus->set_mdc(bus, 0);
230 		if ((reg & 0x10) == 0) {
231 			bus->set_mdio(bus, 0);
232 		} else {
233 			bus->set_mdio(bus, 1);
234 		}
235 		bus->delay(bus);
236 		bus->set_mdc(bus, 1);
237 		bus->delay(bus);
238 		reg <<= 1;
239 	}
240 }
241 
242 /*****************************************************************************
243  *
244  * Read a MII PHY register.
245  *
246  * Returns:
247  *   0 on success
248  */
249 int bb_miiphy_read(const char *devname, unsigned char addr,
250 		   unsigned char reg, unsigned short *value)
251 {
252 	short rdreg; /* register working value */
253 	int v;
254 	int j; /* counter */
255 	struct bb_miiphy_bus *bus;
256 
257 	bus = bb_miiphy_getbus(devname);
258 	if (bus == NULL) {
259 		return -1;
260 	}
261 
262 	if (value == NULL) {
263 		puts("NULL value pointer\n");
264 		return -1;
265 	}
266 
267 	miiphy_pre (bus, 1, addr, reg);
268 
269 	/* tri-state our MDIO I/O pin so we can read */
270 	bus->set_mdc(bus, 0);
271 	bus->mdio_tristate(bus);
272 	bus->delay(bus);
273 	bus->set_mdc(bus, 1);
274 	bus->delay(bus);
275 
276 	/* check the turnaround bit: the PHY should be driving it to zero */
277 	bus->get_mdio(bus, &v);
278 	if (v != 0) {
279 		/* puts ("PHY didn't drive TA low\n"); */
280 		for (j = 0; j < 32; j++) {
281 			bus->set_mdc(bus, 0);
282 			bus->delay(bus);
283 			bus->set_mdc(bus, 1);
284 			bus->delay(bus);
285 		}
286 		/* There is no PHY, set value to 0xFFFF and return */
287 		*value = 0xFFFF;
288 		return -1;
289 	}
290 
291 	bus->set_mdc(bus, 0);
292 	bus->delay(bus);
293 
294 	/* read 16 bits of register data, MSB first */
295 	rdreg = 0;
296 	for (j = 0; j < 16; j++) {
297 		bus->set_mdc(bus, 1);
298 		bus->delay(bus);
299 		rdreg <<= 1;
300 		bus->get_mdio(bus, &v);
301 		rdreg |= (v & 0x1);
302 		bus->set_mdc(bus, 0);
303 		bus->delay(bus);
304 	}
305 
306 	bus->set_mdc(bus, 1);
307 	bus->delay(bus);
308 	bus->set_mdc(bus, 0);
309 	bus->delay(bus);
310 	bus->set_mdc(bus, 1);
311 	bus->delay(bus);
312 
313 	*value = rdreg;
314 
315 #ifdef DEBUG
316 	printf ("miiphy_read(0x%x) @ 0x%x = 0x%04x\n", reg, addr, *value);
317 #endif
318 
319 	return 0;
320 }
321 
322 
323 /*****************************************************************************
324  *
325  * Write a MII PHY register.
326  *
327  * Returns:
328  *   0 on success
329  */
330 int bb_miiphy_write (const char *devname, unsigned char addr,
331 		     unsigned char reg, unsigned short value)
332 {
333 	struct bb_miiphy_bus *bus;
334 	int j;			/* counter */
335 
336 	bus = bb_miiphy_getbus(devname);
337 	if (bus == NULL) {
338 		/* Bus not found! */
339 		return -1;
340 	}
341 
342 	miiphy_pre (bus, 0, addr, reg);
343 
344 	/* send the turnaround (10) */
345 	bus->set_mdc(bus, 0);
346 	bus->set_mdio(bus, 1);
347 	bus->delay(bus);
348 	bus->set_mdc(bus, 1);
349 	bus->delay(bus);
350 	bus->set_mdc(bus, 0);
351 	bus->set_mdio(bus, 0);
352 	bus->delay(bus);
353 	bus->set_mdc(bus, 1);
354 	bus->delay(bus);
355 
356 	/* write 16 bits of register data, MSB first */
357 	for (j = 0; j < 16; j++) {
358 		bus->set_mdc(bus, 0);
359 		if ((value & 0x00008000) == 0) {
360 			bus->set_mdio(bus, 0);
361 		} else {
362 			bus->set_mdio(bus, 1);
363 		}
364 		bus->delay(bus);
365 		bus->set_mdc(bus, 1);
366 		bus->delay(bus);
367 		value <<= 1;
368 	}
369 
370 	/*
371 	 * Tri-state the MDIO line.
372 	 */
373 	bus->mdio_tristate(bus);
374 	bus->set_mdc(bus, 0);
375 	bus->delay(bus);
376 	bus->set_mdc(bus, 1);
377 	bus->delay(bus);
378 
379 	return 0;
380 }
381