xref: /openbmc/u-boot/drivers/net/phy/miiphybb.c (revision 909ea9aa)
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  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 /*
12  * This provides a bit-banged interface to the ethernet MII management
13  * channel.
14  */
15 
16 #include <common.h>
17 #include <ioports.h>
18 #include <ppc_asm.tmpl>
19 #include <miiphy.h>
20 
21 #define BB_MII_RELOCATE(v,off) (v += (v?off:0))
22 
23 DECLARE_GLOBAL_DATA_PTR;
24 
25 #ifndef CONFIG_BITBANGMII_MULTI
26 
27 /*
28  * If CONFIG_BITBANGMII_MULTI is not defined we use a
29  * compatibility layer with the previous miiphybb implementation
30  * based on macros usage.
31  *
32  */
33 static int bb_mii_init_wrap(struct bb_miiphy_bus *bus)
34 {
35 #ifdef MII_INIT
36 	MII_INIT;
37 #endif
38 	return 0;
39 }
40 
41 static int bb_mdio_active_wrap(struct bb_miiphy_bus *bus)
42 {
43 #ifdef MDIO_DECLARE
44 	MDIO_DECLARE;
45 #endif
46 	MDIO_ACTIVE;
47 	return 0;
48 }
49 
50 static int bb_mdio_tristate_wrap(struct bb_miiphy_bus *bus)
51 {
52 #ifdef MDIO_DECLARE
53 	MDIO_DECLARE;
54 #endif
55 	MDIO_TRISTATE;
56 	return 0;
57 }
58 
59 static int bb_set_mdio_wrap(struct bb_miiphy_bus *bus, int v)
60 {
61 #ifdef MDIO_DECLARE
62 	MDIO_DECLARE;
63 #endif
64 	MDIO(v);
65 	return 0;
66 }
67 
68 static int bb_get_mdio_wrap(struct bb_miiphy_bus *bus, int *v)
69 {
70 #ifdef MDIO_DECLARE
71 	MDIO_DECLARE;
72 #endif
73 	*v = MDIO_READ;
74 	return 0;
75 }
76 
77 static int bb_set_mdc_wrap(struct bb_miiphy_bus *bus, int v)
78 {
79 #ifdef MDC_DECLARE
80 	MDC_DECLARE;
81 #endif
82 	MDC(v);
83 	return 0;
84 }
85 
86 static int bb_delay_wrap(struct bb_miiphy_bus *bus)
87 {
88 	MIIDELAY;
89 	return 0;
90 }
91 
92 struct bb_miiphy_bus bb_miiphy_buses[] = {
93 	{
94 		.name = BB_MII_DEVNAME,
95 		.init = bb_mii_init_wrap,
96 		.mdio_active = bb_mdio_active_wrap,
97 		.mdio_tristate = bb_mdio_tristate_wrap,
98 		.set_mdio = bb_set_mdio_wrap,
99 		.get_mdio = bb_get_mdio_wrap,
100 		.set_mdc = bb_set_mdc_wrap,
101 		.delay = bb_delay_wrap,
102 	}
103 };
104 
105 int bb_miiphy_buses_num = sizeof(bb_miiphy_buses) /
106 			  sizeof(bb_miiphy_buses[0]);
107 #endif
108 
109 void bb_miiphy_init(void)
110 {
111 	int i;
112 
113 	for (i = 0; i < bb_miiphy_buses_num; i++) {
114 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
115 		/* Relocate the hook pointers*/
116 		BB_MII_RELOCATE(bb_miiphy_buses[i].init, gd->reloc_off);
117 		BB_MII_RELOCATE(bb_miiphy_buses[i].mdio_active, gd->reloc_off);
118 		BB_MII_RELOCATE(bb_miiphy_buses[i].mdio_tristate, gd->reloc_off);
119 		BB_MII_RELOCATE(bb_miiphy_buses[i].set_mdio, gd->reloc_off);
120 		BB_MII_RELOCATE(bb_miiphy_buses[i].get_mdio, gd->reloc_off);
121 		BB_MII_RELOCATE(bb_miiphy_buses[i].set_mdc, gd->reloc_off);
122 		BB_MII_RELOCATE(bb_miiphy_buses[i].delay, gd->reloc_off);
123 #endif
124 		if (bb_miiphy_buses[i].init != NULL) {
125 			bb_miiphy_buses[i].init(&bb_miiphy_buses[i]);
126 		}
127 	}
128 }
129 
130 static inline struct bb_miiphy_bus *bb_miiphy_getbus(const char *devname)
131 {
132 #ifdef CONFIG_BITBANGMII_MULTI
133 	int i;
134 
135 	/* Search the correct bus */
136 	for (i = 0; i < bb_miiphy_buses_num; i++) {
137 		if (!strcmp(bb_miiphy_buses[i].name, devname)) {
138 			return &bb_miiphy_buses[i];
139 		}
140 	}
141 	return NULL;
142 #else
143 	/* We have just one bitbanging bus */
144 	return &bb_miiphy_buses[0];
145 #endif
146 }
147 
148 /*****************************************************************************
149  *
150  * Utility to send the preamble, address, and register (common to read
151  * and write).
152  */
153 static void miiphy_pre(struct bb_miiphy_bus *bus, char read,
154 		       unsigned char addr, unsigned char reg)
155 {
156 	int j;
157 
158 	/*
159 	 * Send a 32 bit preamble ('1's) with an extra '1' bit for good measure.
160 	 * The IEEE spec says this is a PHY optional requirement.  The AMD
161 	 * 79C874 requires one after power up and one after a MII communications
162 	 * error.  This means that we are doing more preambles than we need,
163 	 * but it is safer and will be much more robust.
164 	 */
165 
166 	bus->mdio_active(bus);
167 	bus->set_mdio(bus, 1);
168 	for (j = 0; j < 32; j++) {
169 		bus->set_mdc(bus, 0);
170 		bus->delay(bus);
171 		bus->set_mdc(bus, 1);
172 		bus->delay(bus);
173 	}
174 
175 	/* send the start bit (01) and the read opcode (10) or write (10) */
176 	bus->set_mdc(bus, 0);
177 	bus->set_mdio(bus, 0);
178 	bus->delay(bus);
179 	bus->set_mdc(bus, 1);
180 	bus->delay(bus);
181 	bus->set_mdc(bus, 0);
182 	bus->set_mdio(bus, 1);
183 	bus->delay(bus);
184 	bus->set_mdc(bus, 1);
185 	bus->delay(bus);
186 	bus->set_mdc(bus, 0);
187 	bus->set_mdio(bus, read);
188 	bus->delay(bus);
189 	bus->set_mdc(bus, 1);
190 	bus->delay(bus);
191 	bus->set_mdc(bus, 0);
192 	bus->set_mdio(bus, !read);
193 	bus->delay(bus);
194 	bus->set_mdc(bus, 1);
195 	bus->delay(bus);
196 
197 	/* send the PHY address */
198 	for (j = 0; j < 5; j++) {
199 		bus->set_mdc(bus, 0);
200 		if ((addr & 0x10) == 0) {
201 			bus->set_mdio(bus, 0);
202 		} else {
203 			bus->set_mdio(bus, 1);
204 		}
205 		bus->delay(bus);
206 		bus->set_mdc(bus, 1);
207 		bus->delay(bus);
208 		addr <<= 1;
209 	}
210 
211 	/* send the register address */
212 	for (j = 0; j < 5; j++) {
213 		bus->set_mdc(bus, 0);
214 		if ((reg & 0x10) == 0) {
215 			bus->set_mdio(bus, 0);
216 		} else {
217 			bus->set_mdio(bus, 1);
218 		}
219 		bus->delay(bus);
220 		bus->set_mdc(bus, 1);
221 		bus->delay(bus);
222 		reg <<= 1;
223 	}
224 }
225 
226 /*****************************************************************************
227  *
228  * Read a MII PHY register.
229  *
230  * Returns:
231  *   0 on success
232  */
233 int bb_miiphy_read(const char *devname, unsigned char addr,
234 		   unsigned char reg, unsigned short *value)
235 {
236 	short rdreg; /* register working value */
237 	int v;
238 	int j; /* counter */
239 	struct bb_miiphy_bus *bus;
240 
241 	bus = bb_miiphy_getbus(devname);
242 	if (bus == NULL) {
243 		return -1;
244 	}
245 
246 	if (value == NULL) {
247 		puts("NULL value pointer\n");
248 		return -1;
249 	}
250 
251 	miiphy_pre (bus, 1, addr, reg);
252 
253 	/* tri-state our MDIO I/O pin so we can read */
254 	bus->set_mdc(bus, 0);
255 	bus->mdio_tristate(bus);
256 	bus->delay(bus);
257 	bus->set_mdc(bus, 1);
258 	bus->delay(bus);
259 
260 	/* check the turnaround bit: the PHY should be driving it to zero */
261 	bus->get_mdio(bus, &v);
262 	if (v != 0) {
263 		/* puts ("PHY didn't drive TA low\n"); */
264 		for (j = 0; j < 32; j++) {
265 			bus->set_mdc(bus, 0);
266 			bus->delay(bus);
267 			bus->set_mdc(bus, 1);
268 			bus->delay(bus);
269 		}
270 		/* There is no PHY, set value to 0xFFFF and return */
271 		*value = 0xFFFF;
272 		return -1;
273 	}
274 
275 	bus->set_mdc(bus, 0);
276 	bus->delay(bus);
277 
278 	/* read 16 bits of register data, MSB first */
279 	rdreg = 0;
280 	for (j = 0; j < 16; j++) {
281 		bus->set_mdc(bus, 1);
282 		bus->delay(bus);
283 		rdreg <<= 1;
284 		bus->get_mdio(bus, &v);
285 		rdreg |= (v & 0x1);
286 		bus->set_mdc(bus, 0);
287 		bus->delay(bus);
288 	}
289 
290 	bus->set_mdc(bus, 1);
291 	bus->delay(bus);
292 	bus->set_mdc(bus, 0);
293 	bus->delay(bus);
294 	bus->set_mdc(bus, 1);
295 	bus->delay(bus);
296 
297 	*value = rdreg;
298 
299 #ifdef DEBUG
300 	printf ("miiphy_read(0x%x) @ 0x%x = 0x%04x\n", reg, addr, *value);
301 #endif
302 
303 	return 0;
304 }
305 
306 
307 /*****************************************************************************
308  *
309  * Write a MII PHY register.
310  *
311  * Returns:
312  *   0 on success
313  */
314 int bb_miiphy_write (const char *devname, unsigned char addr,
315 		     unsigned char reg, unsigned short value)
316 {
317 	struct bb_miiphy_bus *bus;
318 	int j;			/* counter */
319 
320 	bus = bb_miiphy_getbus(devname);
321 	if (bus == NULL) {
322 		/* Bus not found! */
323 		return -1;
324 	}
325 
326 	miiphy_pre (bus, 0, addr, reg);
327 
328 	/* send the turnaround (10) */
329 	bus->set_mdc(bus, 0);
330 	bus->set_mdio(bus, 1);
331 	bus->delay(bus);
332 	bus->set_mdc(bus, 1);
333 	bus->delay(bus);
334 	bus->set_mdc(bus, 0);
335 	bus->set_mdio(bus, 0);
336 	bus->delay(bus);
337 	bus->set_mdc(bus, 1);
338 	bus->delay(bus);
339 
340 	/* write 16 bits of register data, MSB first */
341 	for (j = 0; j < 16; j++) {
342 		bus->set_mdc(bus, 0);
343 		if ((value & 0x00008000) == 0) {
344 			bus->set_mdio(bus, 0);
345 		} else {
346 			bus->set_mdio(bus, 1);
347 		}
348 		bus->delay(bus);
349 		bus->set_mdc(bus, 1);
350 		bus->delay(bus);
351 		value <<= 1;
352 	}
353 
354 	/*
355 	 * Tri-state the MDIO line.
356 	 */
357 	bus->mdio_tristate(bus);
358 	bus->set_mdc(bus, 0);
359 	bus->delay(bus);
360 	bus->set_mdc(bus, 1);
361 	bus->delay(bus);
362 
363 	return 0;
364 }
365