xref: /linux/drivers/net/pcs/pcs-lynx.c (revision 8a5f956a9fb7d74fff681145082acfad5afa6bb8)
1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2 /* Copyright 2020 NXP
3  * Lynx PCS MDIO helpers
4  */
5 
6 #include <linux/mdio.h>
7 #include <linux/phylink.h>
8 #include <linux/pcs-lynx.h>
9 #include <linux/property.h>
10 
11 #define SGMII_CLOCK_PERIOD_NS		8 /* PCS is clocked at 125 MHz */
12 #define LINK_TIMER_VAL(ns)		((u32)((ns) / SGMII_CLOCK_PERIOD_NS))
13 
14 #define LINK_TIMER_LO			0x12
15 #define LINK_TIMER_HI			0x13
16 #define IF_MODE				0x14
17 #define IF_MODE_SGMII_EN		BIT(0)
18 #define IF_MODE_USE_SGMII_AN		BIT(1)
19 #define IF_MODE_SPEED(x)		(((x) << 2) & GENMASK(3, 2))
20 #define IF_MODE_SPEED_MSK		GENMASK(3, 2)
21 #define IF_MODE_HALF_DUPLEX		BIT(4)
22 
23 struct lynx_pcs {
24 	struct phylink_pcs pcs;
25 	struct mdio_device *mdio;
26 };
27 
28 enum sgmii_speed {
29 	SGMII_SPEED_10		= 0,
30 	SGMII_SPEED_100		= 1,
31 	SGMII_SPEED_1000	= 2,
32 	SGMII_SPEED_2500	= 2,
33 };
34 
35 #define phylink_pcs_to_lynx(pl_pcs) container_of((pl_pcs), struct lynx_pcs, pcs)
36 #define lynx_to_phylink_pcs(lynx) (&(lynx)->pcs)
37 
38 static unsigned int lynx_pcs_inband_caps(struct phylink_pcs *pcs,
39 					 phy_interface_t interface)
40 {
41 	switch (interface) {
42 	case PHY_INTERFACE_MODE_1000BASEX:
43 	case PHY_INTERFACE_MODE_SGMII:
44 	case PHY_INTERFACE_MODE_QSGMII:
45 		return LINK_INBAND_DISABLE | LINK_INBAND_ENABLE;
46 
47 	case PHY_INTERFACE_MODE_10GBASER:
48 	case PHY_INTERFACE_MODE_2500BASEX:
49 		return LINK_INBAND_DISABLE;
50 
51 	case PHY_INTERFACE_MODE_USXGMII:
52 	case PHY_INTERFACE_MODE_10G_QXGMII:
53 		return LINK_INBAND_ENABLE;
54 
55 	default:
56 		return 0;
57 	}
58 }
59 
60 static void lynx_pcs_get_state_usxgmii(struct mdio_device *pcs,
61 				       struct phylink_link_state *state)
62 {
63 	struct mii_bus *bus = pcs->bus;
64 	int addr = pcs->addr;
65 	int status, lpa;
66 
67 	status = mdiobus_c45_read(bus, addr, MDIO_MMD_VEND2, MII_BMSR);
68 	if (status < 0)
69 		return;
70 
71 	state->link = !!(status & MDIO_STAT1_LSTATUS);
72 	state->an_complete = !!(status & MDIO_AN_STAT1_COMPLETE);
73 	if (!state->link || !state->an_complete)
74 		return;
75 
76 	lpa = mdiobus_c45_read(bus, addr, MDIO_MMD_VEND2, MII_LPA);
77 	if (lpa < 0)
78 		return;
79 
80 	phylink_decode_usxgmii_word(state, lpa);
81 }
82 
83 static void lynx_pcs_get_state_2500basex(struct mdio_device *pcs,
84 					 struct phylink_link_state *state)
85 {
86 	int bmsr;
87 
88 	bmsr = mdiodev_read(pcs, MII_BMSR);
89 	if (bmsr < 0) {
90 		state->link = false;
91 		return;
92 	}
93 
94 	state->link = !!(bmsr & BMSR_LSTATUS);
95 	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
96 	if (!state->link)
97 		return;
98 
99 	state->speed = SPEED_2500;
100 	state->pause |= MLO_PAUSE_TX | MLO_PAUSE_RX;
101 	state->duplex = DUPLEX_FULL;
102 }
103 
104 static void lynx_pcs_get_state(struct phylink_pcs *pcs, unsigned int neg_mode,
105 			       struct phylink_link_state *state)
106 {
107 	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
108 
109 	switch (state->interface) {
110 	case PHY_INTERFACE_MODE_1000BASEX:
111 	case PHY_INTERFACE_MODE_SGMII:
112 	case PHY_INTERFACE_MODE_QSGMII:
113 		phylink_mii_c22_pcs_get_state(lynx->mdio, neg_mode, state);
114 		break;
115 	case PHY_INTERFACE_MODE_2500BASEX:
116 		lynx_pcs_get_state_2500basex(lynx->mdio, state);
117 		break;
118 	case PHY_INTERFACE_MODE_USXGMII:
119 	case PHY_INTERFACE_MODE_10G_QXGMII:
120 		lynx_pcs_get_state_usxgmii(lynx->mdio, state);
121 		break;
122 	case PHY_INTERFACE_MODE_10GBASER:
123 		phylink_mii_c45_pcs_get_state(lynx->mdio, state);
124 		break;
125 	default:
126 		break;
127 	}
128 
129 	dev_dbg(&lynx->mdio->dev,
130 		"mode=%s/%s/%s link=%u an_complete=%u\n",
131 		phy_modes(state->interface),
132 		phy_speed_to_str(state->speed),
133 		phy_duplex_to_str(state->duplex),
134 		state->link, state->an_complete);
135 }
136 
137 static int lynx_pcs_config_giga(struct mdio_device *pcs,
138 				phy_interface_t interface,
139 				const unsigned long *advertising,
140 				unsigned int neg_mode)
141 {
142 	int link_timer_ns;
143 	u32 link_timer;
144 	u16 if_mode;
145 	int err;
146 
147 	link_timer_ns = phylink_get_link_timer_ns(interface);
148 	if (link_timer_ns > 0) {
149 		link_timer = LINK_TIMER_VAL(link_timer_ns);
150 
151 		mdiodev_write(pcs, LINK_TIMER_LO, link_timer & 0xffff);
152 		mdiodev_write(pcs, LINK_TIMER_HI, link_timer >> 16);
153 	}
154 
155 	if (interface == PHY_INTERFACE_MODE_1000BASEX) {
156 		if_mode = 0;
157 	} else {
158 		/* SGMII and QSGMII */
159 		if_mode = IF_MODE_SGMII_EN;
160 		if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
161 			if_mode |= IF_MODE_USE_SGMII_AN;
162 	}
163 
164 	err = mdiodev_modify(pcs, IF_MODE,
165 			     IF_MODE_SGMII_EN | IF_MODE_USE_SGMII_AN,
166 			     if_mode);
167 	if (err)
168 		return err;
169 
170 	return phylink_mii_c22_pcs_config(pcs, interface, advertising,
171 					  neg_mode);
172 }
173 
174 static int lynx_pcs_config_usxgmii(struct mdio_device *pcs,
175 				   phy_interface_t interface,
176 				   const unsigned long *advertising,
177 				   unsigned int neg_mode)
178 {
179 	struct mii_bus *bus = pcs->bus;
180 	int addr = pcs->addr;
181 
182 	if (neg_mode != PHYLINK_PCS_NEG_INBAND_ENABLED) {
183 		dev_err(&pcs->dev, "%s only supports in-band AN for now\n",
184 			phy_modes(interface));
185 		return -EOPNOTSUPP;
186 	}
187 
188 	/* Configure device ability for the USXGMII Replicator */
189 	return mdiobus_c45_write(bus, addr, MDIO_MMD_VEND2, MII_ADVERTISE,
190 				 MDIO_USXGMII_10G | MDIO_USXGMII_LINK |
191 				 MDIO_USXGMII_FULL_DUPLEX |
192 				 ADVERTISE_SGMII | ADVERTISE_LPACK);
193 }
194 
195 static int lynx_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
196 			   phy_interface_t ifmode,
197 			   const unsigned long *advertising, bool permit)
198 {
199 	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
200 
201 	switch (ifmode) {
202 	case PHY_INTERFACE_MODE_1000BASEX:
203 	case PHY_INTERFACE_MODE_SGMII:
204 	case PHY_INTERFACE_MODE_QSGMII:
205 		return lynx_pcs_config_giga(lynx->mdio, ifmode, advertising,
206 					    neg_mode);
207 	case PHY_INTERFACE_MODE_2500BASEX:
208 		if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
209 			dev_err(&lynx->mdio->dev,
210 				"AN not supported on 3.125GHz SerDes lane\n");
211 			return -EOPNOTSUPP;
212 		}
213 		break;
214 	case PHY_INTERFACE_MODE_USXGMII:
215 	case PHY_INTERFACE_MODE_10G_QXGMII:
216 		return lynx_pcs_config_usxgmii(lynx->mdio, ifmode, advertising,
217 					       neg_mode);
218 	case PHY_INTERFACE_MODE_10GBASER:
219 		/* Nothing to do here for 10GBASER */
220 		break;
221 	default:
222 		return -EOPNOTSUPP;
223 	}
224 
225 	return 0;
226 }
227 
228 static void lynx_pcs_an_restart(struct phylink_pcs *pcs)
229 {
230 	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
231 
232 	phylink_mii_c22_pcs_an_restart(lynx->mdio);
233 }
234 
235 static void lynx_pcs_link_up_sgmii(struct mdio_device *pcs,
236 				   unsigned int neg_mode,
237 				   int speed, int duplex)
238 {
239 	u16 if_mode = 0, sgmii_speed;
240 
241 	/* The PCS needs to be configured manually only
242 	 * when not operating on in-band mode
243 	 */
244 	if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
245 		return;
246 
247 	if (duplex == DUPLEX_HALF)
248 		if_mode |= IF_MODE_HALF_DUPLEX;
249 
250 	switch (speed) {
251 	case SPEED_1000:
252 		sgmii_speed = SGMII_SPEED_1000;
253 		break;
254 	case SPEED_100:
255 		sgmii_speed = SGMII_SPEED_100;
256 		break;
257 	case SPEED_10:
258 		sgmii_speed = SGMII_SPEED_10;
259 		break;
260 	case SPEED_UNKNOWN:
261 		/* Silently don't do anything */
262 		return;
263 	default:
264 		dev_err(&pcs->dev, "Invalid PCS speed %d\n", speed);
265 		return;
266 	}
267 	if_mode |= IF_MODE_SPEED(sgmii_speed);
268 
269 	mdiodev_modify(pcs, IF_MODE,
270 		       IF_MODE_HALF_DUPLEX | IF_MODE_SPEED_MSK,
271 		       if_mode);
272 }
273 
274 /* 2500Base-X is SerDes protocol 7 on Felix and 6 on ENETC. It is a SerDes lane
275  * clocked at 3.125 GHz which encodes symbols with 8b/10b and does not have
276  * auto-negotiation of any link parameters. Electrically it is compatible with
277  * a single lane of XAUI.
278  * The hardware reference manual wants to call this mode SGMII, but it isn't
279  * really, since the fundamental features of SGMII:
280  * - Downgrading the link speed by duplicating symbols
281  * - Auto-negotiation
282  * are not there.
283  * The speed is configured at 1000 in the IF_MODE because the clock frequency
284  * is actually given by a PLL configured in the Reset Configuration Word (RCW).
285  * Since there is no difference between fixed speed SGMII w/o AN and 802.3z w/o
286  * AN, we call this PHY interface type 2500Base-X. In case a PHY negotiates a
287  * lower link speed on line side, the system-side interface remains fixed at
288  * 2500 Mbps and we do rate adaptation through pause frames.
289  */
290 static void lynx_pcs_link_up_2500basex(struct mdio_device *pcs,
291 				       unsigned int neg_mode,
292 				       int speed, int duplex)
293 {
294 	u16 if_mode = 0;
295 
296 	if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
297 		dev_err(&pcs->dev, "AN not supported for 2500BaseX\n");
298 		return;
299 	}
300 
301 	if (duplex == DUPLEX_HALF)
302 		if_mode |= IF_MODE_HALF_DUPLEX;
303 	if_mode |= IF_MODE_SPEED(SGMII_SPEED_2500);
304 
305 	mdiodev_modify(pcs, IF_MODE,
306 		       IF_MODE_HALF_DUPLEX | IF_MODE_SPEED_MSK,
307 		       if_mode);
308 }
309 
310 static void lynx_pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
311 			     phy_interface_t interface,
312 			     int speed, int duplex)
313 {
314 	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
315 
316 	switch (interface) {
317 	case PHY_INTERFACE_MODE_SGMII:
318 	case PHY_INTERFACE_MODE_QSGMII:
319 		lynx_pcs_link_up_sgmii(lynx->mdio, neg_mode, speed, duplex);
320 		break;
321 	case PHY_INTERFACE_MODE_2500BASEX:
322 		lynx_pcs_link_up_2500basex(lynx->mdio, neg_mode, speed, duplex);
323 		break;
324 	case PHY_INTERFACE_MODE_USXGMII:
325 	case PHY_INTERFACE_MODE_10G_QXGMII:
326 		/* At the moment, only in-band AN is supported for USXGMII
327 		 * so nothing to do in link_up
328 		 */
329 		break;
330 	default:
331 		break;
332 	}
333 }
334 
335 static const struct phylink_pcs_ops lynx_pcs_phylink_ops = {
336 	.pcs_inband_caps = lynx_pcs_inband_caps,
337 	.pcs_get_state = lynx_pcs_get_state,
338 	.pcs_config = lynx_pcs_config,
339 	.pcs_an_restart = lynx_pcs_an_restart,
340 	.pcs_link_up = lynx_pcs_link_up,
341 };
342 
343 static const phy_interface_t lynx_interfaces[] = {
344 	PHY_INTERFACE_MODE_SGMII,
345 	PHY_INTERFACE_MODE_QSGMII,
346 	PHY_INTERFACE_MODE_1000BASEX,
347 	PHY_INTERFACE_MODE_2500BASEX,
348 	PHY_INTERFACE_MODE_10GBASER,
349 	PHY_INTERFACE_MODE_USXGMII,
350 	PHY_INTERFACE_MODE_10G_QXGMII,
351 };
352 
353 static struct phylink_pcs *lynx_pcs_create(struct mdio_device *mdio)
354 {
355 	struct lynx_pcs *lynx;
356 	int i;
357 
358 	lynx = kzalloc(sizeof(*lynx), GFP_KERNEL);
359 	if (!lynx)
360 		return ERR_PTR(-ENOMEM);
361 
362 	mdio_device_get(mdio);
363 	lynx->mdio = mdio;
364 	lynx->pcs.ops = &lynx_pcs_phylink_ops;
365 	lynx->pcs.poll = true;
366 
367 	for (i = 0; i < ARRAY_SIZE(lynx_interfaces); i++)
368 		__set_bit(lynx_interfaces[i], lynx->pcs.supported_interfaces);
369 
370 	return lynx_to_phylink_pcs(lynx);
371 }
372 
373 struct phylink_pcs *lynx_pcs_create_mdiodev(struct mii_bus *bus, int addr)
374 {
375 	struct mdio_device *mdio;
376 	struct phylink_pcs *pcs;
377 
378 	mdio = mdio_device_create(bus, addr);
379 	if (IS_ERR(mdio))
380 		return ERR_CAST(mdio);
381 
382 	pcs = lynx_pcs_create(mdio);
383 
384 	/* lynx_create() has taken a refcount on the mdiodev if it was
385 	 * successful. If lynx_create() fails, this will free the mdio
386 	 * device here. In any case, we don't need to hold our reference
387 	 * anymore, and putting it here will allow mdio_device_put() in
388 	 * lynx_destroy() to automatically free the mdio device.
389 	 */
390 	mdio_device_put(mdio);
391 
392 	return pcs;
393 }
394 EXPORT_SYMBOL(lynx_pcs_create_mdiodev);
395 
396 /*
397  * lynx_pcs_create_fwnode() creates a lynx PCS instance from the fwnode
398  * device indicated by node.
399  *
400  * Returns:
401  *  -ENODEV if the fwnode is marked unavailable
402  *  -EPROBE_DEFER if we fail to find the device
403  *  -ENOMEM if we fail to allocate memory
404  *  pointer to a phylink_pcs on success
405  */
406 struct phylink_pcs *lynx_pcs_create_fwnode(struct fwnode_handle *node)
407 {
408 	struct mdio_device *mdio;
409 	struct phylink_pcs *pcs;
410 
411 	if (!fwnode_device_is_available(node))
412 		return ERR_PTR(-ENODEV);
413 
414 	mdio = fwnode_mdio_find_device(node);
415 	if (!mdio)
416 		return ERR_PTR(-EPROBE_DEFER);
417 
418 	pcs = lynx_pcs_create(mdio);
419 
420 	/* lynx_create() has taken a refcount on the mdiodev if it was
421 	 * successful. If lynx_create() fails, this will free the mdio
422 	 * device here. In any case, we don't need to hold our reference
423 	 * anymore, and putting it here will allow mdio_device_put() in
424 	 * lynx_destroy() to automatically free the mdio device.
425 	 */
426 	mdio_device_put(mdio);
427 
428 	return pcs;
429 }
430 EXPORT_SYMBOL_GPL(lynx_pcs_create_fwnode);
431 
432 void lynx_pcs_destroy(struct phylink_pcs *pcs)
433 {
434 	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
435 
436 	mdio_device_put(lynx->mdio);
437 	kfree(lynx);
438 }
439 EXPORT_SYMBOL(lynx_pcs_destroy);
440 
441 MODULE_DESCRIPTION("NXP Lynx PCS phylink library");
442 MODULE_LICENSE("Dual BSD/GPL");
443