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  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
 10#define SGMII_CLOCK_PERIOD_NS		8 /* PCS is clocked at 125 MHz */
 11#define LINK_TIMER_VAL(ns)		((u32)((ns) / SGMII_CLOCK_PERIOD_NS))
 12
 13#define SGMII_AN_LINK_TIMER_NS		1600000 /* defined by SGMII spec */
 14#define IEEE8023_LINK_TIMER_NS		10000000
 15
 16#define LINK_TIMER_LO			0x12
 17#define LINK_TIMER_HI			0x13
 18#define IF_MODE				0x14
 19#define IF_MODE_SGMII_EN		BIT(0)
 20#define IF_MODE_USE_SGMII_AN		BIT(1)
 21#define IF_MODE_SPEED(x)		(((x) << 2) & GENMASK(3, 2))
 22#define IF_MODE_SPEED_MSK		GENMASK(3, 2)
 23#define IF_MODE_HALF_DUPLEX		BIT(4)
 24
 25struct lynx_pcs {
 26	struct phylink_pcs pcs;
 27	struct mdio_device *mdio;
 28};
 29
 30enum sgmii_speed {
 31	SGMII_SPEED_10		= 0,
 32	SGMII_SPEED_100		= 1,
 33	SGMII_SPEED_1000	= 2,
 34	SGMII_SPEED_2500	= 2,
 35};
 36
 37#define phylink_pcs_to_lynx(pl_pcs) container_of((pl_pcs), struct lynx_pcs, pcs)
 38#define lynx_to_phylink_pcs(lynx) (&(lynx)->pcs)
 39
 40struct mdio_device *lynx_get_mdio_device(struct phylink_pcs *pcs)
 41{
 42	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
 43
 44	return lynx->mdio;
 45}
 46EXPORT_SYMBOL(lynx_get_mdio_device);
 47
 48static void lynx_pcs_get_state_usxgmii(struct mdio_device *pcs,
 49				       struct phylink_link_state *state)
 50{
 51	struct mii_bus *bus = pcs->bus;
 52	int addr = pcs->addr;
 53	int status, lpa;
 54
 55	status = mdiobus_c45_read(bus, addr, MDIO_MMD_VEND2, MII_BMSR);
 56	if (status < 0)
 57		return;
 58
 59	state->link = !!(status & MDIO_STAT1_LSTATUS);
 60	state->an_complete = !!(status & MDIO_AN_STAT1_COMPLETE);
 61	if (!state->link || !state->an_complete)
 62		return;
 63
 64	lpa = mdiobus_c45_read(bus, addr, MDIO_MMD_VEND2, MII_LPA);
 65	if (lpa < 0)
 66		return;
 67
 68	phylink_decode_usxgmii_word(state, lpa);
 69}
 70
 71static void lynx_pcs_get_state_2500basex(struct mdio_device *pcs,
 72					 struct phylink_link_state *state)
 73{
 74	int bmsr, lpa;
 75
 76	bmsr = mdiodev_read(pcs, MII_BMSR);
 77	lpa = mdiodev_read(pcs, MII_LPA);
 78	if (bmsr < 0 || lpa < 0) {
 79		state->link = false;
 80		return;
 81	}
 82
 83	state->link = !!(bmsr & BMSR_LSTATUS);
 84	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
 85	if (!state->link)
 86		return;
 87
 88	state->speed = SPEED_2500;
 89	state->pause |= MLO_PAUSE_TX | MLO_PAUSE_RX;
 90	state->duplex = DUPLEX_FULL;
 91}
 92
 93static void lynx_pcs_get_state(struct phylink_pcs *pcs,
 94			       struct phylink_link_state *state)
 95{
 96	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
 97
 98	switch (state->interface) {
 99	case PHY_INTERFACE_MODE_1000BASEX:
100	case PHY_INTERFACE_MODE_SGMII:
101	case PHY_INTERFACE_MODE_QSGMII:
102		phylink_mii_c22_pcs_get_state(lynx->mdio, state);
103		break;
104	case PHY_INTERFACE_MODE_2500BASEX:
105		lynx_pcs_get_state_2500basex(lynx->mdio, state);
106		break;
107	case PHY_INTERFACE_MODE_USXGMII:
108		lynx_pcs_get_state_usxgmii(lynx->mdio, state);
109		break;
110	case PHY_INTERFACE_MODE_10GBASER:
111		phylink_mii_c45_pcs_get_state(lynx->mdio, state);
112		break;
113	default:
114		break;
115	}
116
117	dev_dbg(&lynx->mdio->dev,
118		"mode=%s/%s/%s link=%u an_enabled=%u an_complete=%u\n",
119		phy_modes(state->interface),
120		phy_speed_to_str(state->speed),
121		phy_duplex_to_str(state->duplex),
122		state->link, state->an_enabled, state->an_complete);
123}
124
125static int lynx_pcs_config_giga(struct mdio_device *pcs, unsigned int mode,
126				phy_interface_t interface,
127				const unsigned long *advertising)
128{
129	u32 link_timer;
130	u16 if_mode;
131	int err;
132
133	if (interface == PHY_INTERFACE_MODE_1000BASEX) {
134		link_timer = LINK_TIMER_VAL(IEEE8023_LINK_TIMER_NS);
135		mdiodev_write(pcs, LINK_TIMER_LO, link_timer & 0xffff);
136		mdiodev_write(pcs, LINK_TIMER_HI, link_timer >> 16);
137
138		if_mode = 0;
139	} else {
140		if_mode = IF_MODE_SGMII_EN;
141		if (mode == MLO_AN_INBAND) {
142			if_mode |= IF_MODE_USE_SGMII_AN;
143
144			/* Adjust link timer for SGMII */
145			link_timer = LINK_TIMER_VAL(SGMII_AN_LINK_TIMER_NS);
146			mdiodev_write(pcs, LINK_TIMER_LO, link_timer & 0xffff);
147			mdiodev_write(pcs, LINK_TIMER_HI, link_timer >> 16);
148		}
149	}
150
151	err = mdiodev_modify(pcs, IF_MODE,
152			     IF_MODE_SGMII_EN | IF_MODE_USE_SGMII_AN,
153			     if_mode);
154	if (err)
155		return err;
156
157	return phylink_mii_c22_pcs_config(pcs, mode, interface, advertising);
158}
159
160static int lynx_pcs_config_usxgmii(struct mdio_device *pcs, unsigned int mode,
161				   const unsigned long *advertising)
162{
163	struct mii_bus *bus = pcs->bus;
164	int addr = pcs->addr;
165
166	if (!phylink_autoneg_inband(mode)) {
167		dev_err(&pcs->dev, "USXGMII only supports in-band AN for now\n");
168		return -EOPNOTSUPP;
169	}
170
171	/* Configure device ability for the USXGMII Replicator */
172	return mdiobus_c45_write(bus, addr, MDIO_MMD_VEND2, MII_ADVERTISE,
173				 MDIO_USXGMII_10G | MDIO_USXGMII_LINK |
174				 MDIO_USXGMII_FULL_DUPLEX |
175				 ADVERTISE_SGMII | ADVERTISE_LPACK);
176}
177
178static int lynx_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
179			   phy_interface_t ifmode,
180			   const unsigned long *advertising,
181			   bool permit)
182{
183	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
184
185	switch (ifmode) {
186	case PHY_INTERFACE_MODE_1000BASEX:
187	case PHY_INTERFACE_MODE_SGMII:
188	case PHY_INTERFACE_MODE_QSGMII:
189		return lynx_pcs_config_giga(lynx->mdio, mode, ifmode,
190					    advertising);
191	case PHY_INTERFACE_MODE_2500BASEX:
192		if (phylink_autoneg_inband(mode)) {
193			dev_err(&lynx->mdio->dev,
194				"AN not supported on 3.125GHz SerDes lane\n");
195			return -EOPNOTSUPP;
196		}
197		break;
198	case PHY_INTERFACE_MODE_USXGMII:
199		return lynx_pcs_config_usxgmii(lynx->mdio, mode, advertising);
200	case PHY_INTERFACE_MODE_10GBASER:
201		/* Nothing to do here for 10GBASER */
202		break;
203	default:
204		return -EOPNOTSUPP;
205	}
206
207	return 0;
208}
209
210static void lynx_pcs_an_restart(struct phylink_pcs *pcs)
211{
212	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
213
214	phylink_mii_c22_pcs_an_restart(lynx->mdio);
215}
216
217static void lynx_pcs_link_up_sgmii(struct mdio_device *pcs, unsigned int mode,
218				   int speed, int duplex)
219{
220	u16 if_mode = 0, sgmii_speed;
221
222	/* The PCS needs to be configured manually only
223	 * when not operating on in-band mode
224	 */
225	if (mode == MLO_AN_INBAND)
226		return;
227
228	if (duplex == DUPLEX_HALF)
229		if_mode |= IF_MODE_HALF_DUPLEX;
230
231	switch (speed) {
232	case SPEED_1000:
233		sgmii_speed = SGMII_SPEED_1000;
234		break;
235	case SPEED_100:
236		sgmii_speed = SGMII_SPEED_100;
237		break;
238	case SPEED_10:
239		sgmii_speed = SGMII_SPEED_10;
240		break;
241	case SPEED_UNKNOWN:
242		/* Silently don't do anything */
243		return;
244	default:
245		dev_err(&pcs->dev, "Invalid PCS speed %d\n", speed);
246		return;
247	}
248	if_mode |= IF_MODE_SPEED(sgmii_speed);
249
250	mdiodev_modify(pcs, IF_MODE,
251		       IF_MODE_HALF_DUPLEX | IF_MODE_SPEED_MSK,
252		       if_mode);
253}
254
255/* 2500Base-X is SerDes protocol 7 on Felix and 6 on ENETC. It is a SerDes lane
256 * clocked at 3.125 GHz which encodes symbols with 8b/10b and does not have
257 * auto-negotiation of any link parameters. Electrically it is compatible with
258 * a single lane of XAUI.
259 * The hardware reference manual wants to call this mode SGMII, but it isn't
260 * really, since the fundamental features of SGMII:
261 * - Downgrading the link speed by duplicating symbols
262 * - Auto-negotiation
263 * are not there.
264 * The speed is configured at 1000 in the IF_MODE because the clock frequency
265 * is actually given by a PLL configured in the Reset Configuration Word (RCW).
266 * Since there is no difference between fixed speed SGMII w/o AN and 802.3z w/o
267 * AN, we call this PHY interface type 2500Base-X. In case a PHY negotiates a
268 * lower link speed on line side, the system-side interface remains fixed at
269 * 2500 Mbps and we do rate adaptation through pause frames.
270 */
271static void lynx_pcs_link_up_2500basex(struct mdio_device *pcs,
272				       unsigned int mode,
273				       int speed, int duplex)
274{
275	u16 if_mode = 0;
276
277	if (mode == MLO_AN_INBAND) {
278		dev_err(&pcs->dev, "AN not supported for 2500BaseX\n");
279		return;
280	}
281
282	if (duplex == DUPLEX_HALF)
283		if_mode |= IF_MODE_HALF_DUPLEX;
284	if_mode |= IF_MODE_SPEED(SGMII_SPEED_2500);
285
286	mdiodev_modify(pcs, IF_MODE,
287		       IF_MODE_HALF_DUPLEX | IF_MODE_SPEED_MSK,
288		       if_mode);
289}
290
291static void lynx_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
292			     phy_interface_t interface,
293			     int speed, int duplex)
294{
295	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
296
297	switch (interface) {
298	case PHY_INTERFACE_MODE_SGMII:
299	case PHY_INTERFACE_MODE_QSGMII:
300		lynx_pcs_link_up_sgmii(lynx->mdio, mode, speed, duplex);
301		break;
302	case PHY_INTERFACE_MODE_2500BASEX:
303		lynx_pcs_link_up_2500basex(lynx->mdio, mode, speed, duplex);
304		break;
305	case PHY_INTERFACE_MODE_USXGMII:
306		/* At the moment, only in-band AN is supported for USXGMII
307		 * so nothing to do in link_up
308		 */
309		break;
310	default:
311		break;
312	}
313}
314
315static const struct phylink_pcs_ops lynx_pcs_phylink_ops = {
316	.pcs_get_state = lynx_pcs_get_state,
317	.pcs_config = lynx_pcs_config,
318	.pcs_an_restart = lynx_pcs_an_restart,
319	.pcs_link_up = lynx_pcs_link_up,
320};
321
322struct phylink_pcs *lynx_pcs_create(struct mdio_device *mdio)
323{
324	struct lynx_pcs *lynx;
325
326	lynx = kzalloc(sizeof(*lynx), GFP_KERNEL);
327	if (!lynx)
328		return NULL;
329
330	lynx->mdio = mdio;
331	lynx->pcs.ops = &lynx_pcs_phylink_ops;
332	lynx->pcs.poll = true;
333
334	return lynx_to_phylink_pcs(lynx);
335}
336EXPORT_SYMBOL(lynx_pcs_create);
337
338void lynx_pcs_destroy(struct phylink_pcs *pcs)
339{
340	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
341
342	kfree(lynx);
343}
344EXPORT_SYMBOL(lynx_pcs_destroy);
345
346MODULE_LICENSE("Dual BSD/GPL");