xref: /openbmc/u-boot/drivers/net/phy/miiphybb.c (revision 90c08fa0)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2009 Industrie Dial Face S.p.A.
4  * Luigi 'Comio' Mantellini <luigi.mantellini@idf-hit.com>
5  *
6  * (C) Copyright 2001
7  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
8  */
9 
10 /*
11  * This provides a bit-banged interface to the ethernet MII management
12  * channel.
13  */
14 
15 #include <common.h>
16 #include <ioports.h>
17 #include <ppc_asm.tmpl>
18 #include <miiphy.h>
19 
20 #define BB_MII_RELOCATE(v,off) (v += (v?off:0))
21 
22 DECLARE_GLOBAL_DATA_PTR;
23 
24 #ifndef CONFIG_BITBANGMII_MULTI
25 
26 /*
27  * If CONFIG_BITBANGMII_MULTI is not defined we use a
28  * compatibility layer with the previous miiphybb implementation
29  * based on macros usage.
30  *
31  */
32 static int bb_mii_init_wrap(struct bb_miiphy_bus *bus)
33 {
34 #ifdef MII_INIT
35 	MII_INIT;
36 #endif
37 	return 0;
38 }
39 
40 static int bb_mdio_active_wrap(struct bb_miiphy_bus *bus)
41 {
42 #ifdef MDIO_DECLARE
43 	MDIO_DECLARE;
44 #endif
45 	MDIO_ACTIVE;
46 	return 0;
47 }
48 
49 static int bb_mdio_tristate_wrap(struct bb_miiphy_bus *bus)
50 {
51 #ifdef MDIO_DECLARE
52 	MDIO_DECLARE;
53 #endif
54 	MDIO_TRISTATE;
55 	return 0;
56 }
57 
58 static int bb_set_mdio_wrap(struct bb_miiphy_bus *bus, int v)
59 {
60 #ifdef MDIO_DECLARE
61 	MDIO_DECLARE;
62 #endif
63 	MDIO(v);
64 	return 0;
65 }
66 
67 static int bb_get_mdio_wrap(struct bb_miiphy_bus *bus, int *v)
68 {
69 #ifdef MDIO_DECLARE
70 	MDIO_DECLARE;
71 #endif
72 	*v = MDIO_READ;
73 	return 0;
74 }
75 
76 static int bb_set_mdc_wrap(struct bb_miiphy_bus *bus, int v)
77 {
78 #ifdef MDC_DECLARE
79 	MDC_DECLARE;
80 #endif
81 	MDC(v);
82 	return 0;
83 }
84 
85 static int bb_delay_wrap(struct bb_miiphy_bus *bus)
86 {
87 	MIIDELAY;
88 	return 0;
89 }
90 
91 struct bb_miiphy_bus bb_miiphy_buses[] = {
92 	{
93 		.name = BB_MII_DEVNAME,
94 		.init = bb_mii_init_wrap,
95 		.mdio_active = bb_mdio_active_wrap,
96 		.mdio_tristate = bb_mdio_tristate_wrap,
97 		.set_mdio = bb_set_mdio_wrap,
98 		.get_mdio = bb_get_mdio_wrap,
99 		.set_mdc = bb_set_mdc_wrap,
100 		.delay = bb_delay_wrap,
101 	}
102 };
103 
104 int bb_miiphy_buses_num = sizeof(bb_miiphy_buses) /
105 			  sizeof(bb_miiphy_buses[0]);
106 #endif
107 
108 void bb_miiphy_init(void)
109 {
110 	int i;
111 
112 	for (i = 0; i < bb_miiphy_buses_num; i++) {
113 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
114 		/* Relocate the hook pointers*/
115 		BB_MII_RELOCATE(bb_miiphy_buses[i].init, gd->reloc_off);
116 		BB_MII_RELOCATE(bb_miiphy_buses[i].mdio_active, gd->reloc_off);
117 		BB_MII_RELOCATE(bb_miiphy_buses[i].mdio_tristate, gd->reloc_off);
118 		BB_MII_RELOCATE(bb_miiphy_buses[i].set_mdio, gd->reloc_off);
119 		BB_MII_RELOCATE(bb_miiphy_buses[i].get_mdio, gd->reloc_off);
120 		BB_MII_RELOCATE(bb_miiphy_buses[i].set_mdc, gd->reloc_off);
121 		BB_MII_RELOCATE(bb_miiphy_buses[i].delay, gd->reloc_off);
122 #endif
123 		if (bb_miiphy_buses[i].init != NULL) {
124 			bb_miiphy_buses[i].init(&bb_miiphy_buses[i]);
125 		}
126 	}
127 }
128 
129 static inline struct bb_miiphy_bus *bb_miiphy_getbus(const char *devname)
130 {
131 #ifdef CONFIG_BITBANGMII_MULTI
132 	int i;
133 
134 	/* Search the correct bus */
135 	for (i = 0; i < bb_miiphy_buses_num; i++) {
136 		if (!strcmp(bb_miiphy_buses[i].name, devname)) {
137 			return &bb_miiphy_buses[i];
138 		}
139 	}
140 	return NULL;
141 #else
142 	/* We have just one bitbanging bus */
143 	return &bb_miiphy_buses[0];
144 #endif
145 }
146 
147 /*****************************************************************************
148  *
149  * Utility to send the preamble, address, and register (common to read
150  * and write).
151  */
152 static void miiphy_pre(struct bb_miiphy_bus *bus, char read,
153 		       unsigned char addr, unsigned char reg)
154 {
155 	int j;
156 
157 	/*
158 	 * Send a 32 bit preamble ('1's) with an extra '1' bit for good measure.
159 	 * The IEEE spec says this is a PHY optional requirement.  The AMD
160 	 * 79C874 requires one after power up and one after a MII communications
161 	 * error.  This means that we are doing more preambles than we need,
162 	 * but it is safer and will be much more robust.
163 	 */
164 
165 	bus->mdio_active(bus);
166 	bus->set_mdio(bus, 1);
167 	for (j = 0; j < 32; j++) {
168 		bus->set_mdc(bus, 0);
169 		bus->delay(bus);
170 		bus->set_mdc(bus, 1);
171 		bus->delay(bus);
172 	}
173 
174 	/* send the start bit (01) and the read opcode (10) or write (10) */
175 	bus->set_mdc(bus, 0);
176 	bus->set_mdio(bus, 0);
177 	bus->delay(bus);
178 	bus->set_mdc(bus, 1);
179 	bus->delay(bus);
180 	bus->set_mdc(bus, 0);
181 	bus->set_mdio(bus, 1);
182 	bus->delay(bus);
183 	bus->set_mdc(bus, 1);
184 	bus->delay(bus);
185 	bus->set_mdc(bus, 0);
186 	bus->set_mdio(bus, read);
187 	bus->delay(bus);
188 	bus->set_mdc(bus, 1);
189 	bus->delay(bus);
190 	bus->set_mdc(bus, 0);
191 	bus->set_mdio(bus, !read);
192 	bus->delay(bus);
193 	bus->set_mdc(bus, 1);
194 	bus->delay(bus);
195 
196 	/* send the PHY address */
197 	for (j = 0; j < 5; j++) {
198 		bus->set_mdc(bus, 0);
199 		if ((addr & 0x10) == 0) {
200 			bus->set_mdio(bus, 0);
201 		} else {
202 			bus->set_mdio(bus, 1);
203 		}
204 		bus->delay(bus);
205 		bus->set_mdc(bus, 1);
206 		bus->delay(bus);
207 		addr <<= 1;
208 	}
209 
210 	/* send the register address */
211 	for (j = 0; j < 5; j++) {
212 		bus->set_mdc(bus, 0);
213 		if ((reg & 0x10) == 0) {
214 			bus->set_mdio(bus, 0);
215 		} else {
216 			bus->set_mdio(bus, 1);
217 		}
218 		bus->delay(bus);
219 		bus->set_mdc(bus, 1);
220 		bus->delay(bus);
221 		reg <<= 1;
222 	}
223 }
224 
225 /*****************************************************************************
226  *
227  * Read a MII PHY register.
228  *
229  * Returns:
230  *   0 on success
231  */
232 int bb_miiphy_read(struct mii_dev *miidev, int addr, int devad, int reg)
233 {
234 	unsigned short rdreg; /* register working value */
235 	int v;
236 	int j; /* counter */
237 	struct bb_miiphy_bus *bus;
238 
239 	bus = bb_miiphy_getbus(miidev->name);
240 	if (bus == NULL) {
241 		return -1;
242 	}
243 
244 	miiphy_pre (bus, 1, addr, reg);
245 
246 	/* tri-state our MDIO I/O pin so we can read */
247 	bus->set_mdc(bus, 0);
248 	bus->mdio_tristate(bus);
249 	bus->delay(bus);
250 	bus->set_mdc(bus, 1);
251 	bus->delay(bus);
252 
253 	/* check the turnaround bit: the PHY should be driving it to zero */
254 	bus->get_mdio(bus, &v);
255 	if (v != 0) {
256 		/* puts ("PHY didn't drive TA low\n"); */
257 		for (j = 0; j < 32; j++) {
258 			bus->set_mdc(bus, 0);
259 			bus->delay(bus);
260 			bus->set_mdc(bus, 1);
261 			bus->delay(bus);
262 		}
263 		/* There is no PHY, return */
264 		return -1;
265 	}
266 
267 	bus->set_mdc(bus, 0);
268 	bus->delay(bus);
269 
270 	/* read 16 bits of register data, MSB first */
271 	rdreg = 0;
272 	for (j = 0; j < 16; j++) {
273 		bus->set_mdc(bus, 1);
274 		bus->delay(bus);
275 		rdreg <<= 1;
276 		bus->get_mdio(bus, &v);
277 		rdreg |= (v & 0x1);
278 		bus->set_mdc(bus, 0);
279 		bus->delay(bus);
280 	}
281 
282 	bus->set_mdc(bus, 1);
283 	bus->delay(bus);
284 	bus->set_mdc(bus, 0);
285 	bus->delay(bus);
286 	bus->set_mdc(bus, 1);
287 	bus->delay(bus);
288 
289 #ifdef DEBUG
290 	printf("miiphy_read(0x%x) @ 0x%x = 0x%04x\n", reg, addr, rdreg);
291 #endif
292 
293 	return rdreg;
294 }
295 
296 
297 /*****************************************************************************
298  *
299  * Write a MII PHY register.
300  *
301  * Returns:
302  *   0 on success
303  */
304 int bb_miiphy_write(struct mii_dev *miidev, int addr, int devad, int reg,
305 		    u16 value)
306 {
307 	struct bb_miiphy_bus *bus;
308 	int j;			/* counter */
309 
310 	bus = bb_miiphy_getbus(miidev->name);
311 	if (bus == NULL) {
312 		/* Bus not found! */
313 		return -1;
314 	}
315 
316 	miiphy_pre (bus, 0, addr, reg);
317 
318 	/* send the turnaround (10) */
319 	bus->set_mdc(bus, 0);
320 	bus->set_mdio(bus, 1);
321 	bus->delay(bus);
322 	bus->set_mdc(bus, 1);
323 	bus->delay(bus);
324 	bus->set_mdc(bus, 0);
325 	bus->set_mdio(bus, 0);
326 	bus->delay(bus);
327 	bus->set_mdc(bus, 1);
328 	bus->delay(bus);
329 
330 	/* write 16 bits of register data, MSB first */
331 	for (j = 0; j < 16; j++) {
332 		bus->set_mdc(bus, 0);
333 		if ((value & 0x00008000) == 0) {
334 			bus->set_mdio(bus, 0);
335 		} else {
336 			bus->set_mdio(bus, 1);
337 		}
338 		bus->delay(bus);
339 		bus->set_mdc(bus, 1);
340 		bus->delay(bus);
341 		value <<= 1;
342 	}
343 
344 	/*
345 	 * Tri-state the MDIO line.
346 	 */
347 	bus->mdio_tristate(bus);
348 	bus->set_mdc(bus, 0);
349 	bus->delay(bus);
350 	bus->set_mdc(bus, 1);
351 	bus->delay(bus);
352 
353 	return 0;
354 }
355