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