xref: /openbmc/u-boot/drivers/net/phy/miiphybb.c (revision 20c700f8)
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(struct mii_dev *miidev, int addr, int devad, int reg)
234 {
235 	short rdreg; /* register working value */
236 	int v;
237 	int j; /* counter */
238 	struct bb_miiphy_bus *bus;
239 
240 	bus = bb_miiphy_getbus(miidev->name);
241 	if (bus == NULL) {
242 		return -1;
243 	}
244 
245 	miiphy_pre (bus, 1, addr, reg);
246 
247 	/* tri-state our MDIO I/O pin so we can read */
248 	bus->set_mdc(bus, 0);
249 	bus->mdio_tristate(bus);
250 	bus->delay(bus);
251 	bus->set_mdc(bus, 1);
252 	bus->delay(bus);
253 
254 	/* check the turnaround bit: the PHY should be driving it to zero */
255 	bus->get_mdio(bus, &v);
256 	if (v != 0) {
257 		/* puts ("PHY didn't drive TA low\n"); */
258 		for (j = 0; j < 32; j++) {
259 			bus->set_mdc(bus, 0);
260 			bus->delay(bus);
261 			bus->set_mdc(bus, 1);
262 			bus->delay(bus);
263 		}
264 		/* There is no PHY, return */
265 		return -1;
266 	}
267 
268 	bus->set_mdc(bus, 0);
269 	bus->delay(bus);
270 
271 	/* read 16 bits of register data, MSB first */
272 	rdreg = 0;
273 	for (j = 0; j < 16; j++) {
274 		bus->set_mdc(bus, 1);
275 		bus->delay(bus);
276 		rdreg <<= 1;
277 		bus->get_mdio(bus, &v);
278 		rdreg |= (v & 0x1);
279 		bus->set_mdc(bus, 0);
280 		bus->delay(bus);
281 	}
282 
283 	bus->set_mdc(bus, 1);
284 	bus->delay(bus);
285 	bus->set_mdc(bus, 0);
286 	bus->delay(bus);
287 	bus->set_mdc(bus, 1);
288 	bus->delay(bus);
289 
290 #ifdef DEBUG
291 	printf("miiphy_read(0x%x) @ 0x%x = 0x%04x\n", reg, addr, rdreg);
292 #endif
293 
294 	return rdreg;
295 }
296 
297 
298 /*****************************************************************************
299  *
300  * Write a MII PHY register.
301  *
302  * Returns:
303  *   0 on success
304  */
305 int bb_miiphy_write(struct mii_dev *miidev, int addr, int devad, int reg,
306 		    u16 value)
307 {
308 	struct bb_miiphy_bus *bus;
309 	int j;			/* counter */
310 
311 	bus = bb_miiphy_getbus(miidev->name);
312 	if (bus == NULL) {
313 		/* Bus not found! */
314 		return -1;
315 	}
316 
317 	miiphy_pre (bus, 0, addr, reg);
318 
319 	/* send the turnaround (10) */
320 	bus->set_mdc(bus, 0);
321 	bus->set_mdio(bus, 1);
322 	bus->delay(bus);
323 	bus->set_mdc(bus, 1);
324 	bus->delay(bus);
325 	bus->set_mdc(bus, 0);
326 	bus->set_mdio(bus, 0);
327 	bus->delay(bus);
328 	bus->set_mdc(bus, 1);
329 	bus->delay(bus);
330 
331 	/* write 16 bits of register data, MSB first */
332 	for (j = 0; j < 16; j++) {
333 		bus->set_mdc(bus, 0);
334 		if ((value & 0x00008000) == 0) {
335 			bus->set_mdio(bus, 0);
336 		} else {
337 			bus->set_mdio(bus, 1);
338 		}
339 		bus->delay(bus);
340 		bus->set_mdc(bus, 1);
341 		bus->delay(bus);
342 		value <<= 1;
343 	}
344 
345 	/*
346 	 * Tri-state the MDIO line.
347 	 */
348 	bus->mdio_tristate(bus);
349 	bus->set_mdc(bus, 0);
350 	bus->delay(bus);
351 	bus->set_mdc(bus, 1);
352 	bus->delay(bus);
353 
354 	return 0;
355 }
356