xref: /linux/drivers/net/dsa/mv88e6xxx/pcs-6352.c (revision 2ee738e90e80850582cbe10f34c6447965c1d87b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Marvell 88E6352 family SERDES PCS support
4  *
5  * Copyright (c) 2008 Marvell Semiconductor
6  *
7  * Copyright (c) 2017 Andrew Lunn <andrew@lunn.ch>
8  */
9 #include <linux/phylink.h>
10 
11 #include "global2.h"
12 #include "port.h"
13 #include "serdes.h"
14 
15 /* Definitions from drivers/net/phy/marvell.c, which would be good to reuse. */
16 #define MII_M1011_PHY_STATUS		17
17 #define MII_M1011_IMASK			18
18 #define MII_M1011_IMASK_LINK_CHANGE	BIT(10)
19 #define MII_M1011_IEVENT		19
20 #define MII_M1011_IEVENT_LINK_CHANGE	BIT(10)
21 #define MII_MARVELL_PHY_PAGE		22
22 #define MII_MARVELL_FIBER_PAGE		1
23 
24 struct marvell_c22_pcs {
25 	struct mdio_device mdio;
26 	struct phylink_pcs phylink_pcs;
27 	unsigned int irq;
28 	char name[64];
29 	bool (*link_check)(struct marvell_c22_pcs *mpcs);
30 	struct mv88e6xxx_port *port;
31 };
32 
33 static struct marvell_c22_pcs *pcs_to_marvell_c22_pcs(struct phylink_pcs *pcs)
34 {
35 	return container_of(pcs, struct marvell_c22_pcs, phylink_pcs);
36 }
37 
38 static int marvell_c22_pcs_set_fiber_page(struct marvell_c22_pcs *mpcs)
39 {
40 	u16 page;
41 	int err;
42 
43 	mutex_lock(&mpcs->mdio.bus->mdio_lock);
44 
45 	err = __mdiodev_read(&mpcs->mdio, MII_MARVELL_PHY_PAGE);
46 	if (err < 0) {
47 		dev_err(mpcs->mdio.dev.parent,
48 			"%s: can't read Serdes page register: %pe\n",
49 			mpcs->name, ERR_PTR(err));
50 		return err;
51 	}
52 
53 	page = err;
54 
55 	err = __mdiodev_write(&mpcs->mdio, MII_MARVELL_PHY_PAGE,
56 			      MII_MARVELL_FIBER_PAGE);
57 	if (err) {
58 		dev_err(mpcs->mdio.dev.parent,
59 			"%s: can't set Serdes page register: %pe\n",
60 			mpcs->name, ERR_PTR(err));
61 		return err;
62 	}
63 
64 	return page;
65 }
66 
67 static int marvell_c22_pcs_restore_page(struct marvell_c22_pcs *mpcs,
68 					int oldpage, int ret)
69 {
70 	int err;
71 
72 	if (oldpage >= 0) {
73 		err = __mdiodev_write(&mpcs->mdio, MII_MARVELL_PHY_PAGE,
74 				      oldpage);
75 		if (err)
76 			dev_err(mpcs->mdio.dev.parent,
77 				"%s: can't restore Serdes page register: %pe\n",
78 				mpcs->name, ERR_PTR(err));
79 		if (!err || ret < 0)
80 			err = ret;
81 	} else {
82 		err = oldpage;
83 	}
84 	mutex_unlock(&mpcs->mdio.bus->mdio_lock);
85 
86 	return err;
87 }
88 
89 static irqreturn_t marvell_c22_pcs_handle_irq(int irq, void *dev_id)
90 {
91 	struct marvell_c22_pcs *mpcs = dev_id;
92 	irqreturn_t status = IRQ_NONE;
93 	int err, oldpage;
94 
95 	oldpage = marvell_c22_pcs_set_fiber_page(mpcs);
96 	if (oldpage < 0)
97 		goto fail;
98 
99 	err = __mdiodev_read(&mpcs->mdio, MII_M1011_IEVENT);
100 	if (err >= 0 && err & MII_M1011_IEVENT_LINK_CHANGE) {
101 		phylink_pcs_change(&mpcs->phylink_pcs, true);
102 		status = IRQ_HANDLED;
103 	}
104 
105 fail:
106 	marvell_c22_pcs_restore_page(mpcs, oldpage, 0);
107 
108 	return status;
109 }
110 
111 static int marvell_c22_pcs_modify(struct marvell_c22_pcs *mpcs, u8 reg,
112 				  u16 mask, u16 val)
113 {
114 	int oldpage, err = 0;
115 
116 	oldpage = marvell_c22_pcs_set_fiber_page(mpcs);
117 	if (oldpage >= 0)
118 		err = __mdiodev_modify(&mpcs->mdio, reg, mask, val);
119 
120 	return marvell_c22_pcs_restore_page(mpcs, oldpage, err);
121 }
122 
123 static int marvell_c22_pcs_power(struct marvell_c22_pcs *mpcs,
124 				 bool on)
125 {
126 	u16 val = on ? 0 : BMCR_PDOWN;
127 
128 	return marvell_c22_pcs_modify(mpcs, MII_BMCR, BMCR_PDOWN, val);
129 }
130 
131 static int marvell_c22_pcs_control_irq(struct marvell_c22_pcs *mpcs,
132 				       bool enable)
133 {
134 	u16 val = enable ? MII_M1011_IMASK_LINK_CHANGE : 0;
135 
136 	return marvell_c22_pcs_modify(mpcs, MII_M1011_IMASK,
137 				      MII_M1011_IMASK_LINK_CHANGE, val);
138 }
139 
140 static int marvell_c22_pcs_enable(struct phylink_pcs *pcs)
141 {
142 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
143 	int err;
144 
145 	err = marvell_c22_pcs_power(mpcs, true);
146 	if (err)
147 		return err;
148 
149 	return marvell_c22_pcs_control_irq(mpcs, !!mpcs->irq);
150 }
151 
152 static void marvell_c22_pcs_disable(struct phylink_pcs *pcs)
153 {
154 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
155 
156 	marvell_c22_pcs_control_irq(mpcs, false);
157 	marvell_c22_pcs_power(mpcs, false);
158 }
159 
160 static void marvell_c22_pcs_get_state(struct phylink_pcs *pcs,
161 				      unsigned int neg_mode,
162 				      struct phylink_link_state *state)
163 {
164 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
165 	int oldpage, bmsr, lpa, status;
166 
167 	state->link = false;
168 
169 	if (mpcs->link_check && !mpcs->link_check(mpcs))
170 		return;
171 
172 	oldpage = marvell_c22_pcs_set_fiber_page(mpcs);
173 	if (oldpage >= 0) {
174 		bmsr = __mdiodev_read(&mpcs->mdio, MII_BMSR);
175 		lpa = __mdiodev_read(&mpcs->mdio, MII_LPA);
176 		status = __mdiodev_read(&mpcs->mdio, MII_M1011_PHY_STATUS);
177 	}
178 
179 	if (marvell_c22_pcs_restore_page(mpcs, oldpage, 0) >= 0 &&
180 	    bmsr >= 0 && lpa >= 0 && status >= 0)
181 		mv88e6xxx_pcs_decode_state(mpcs->mdio.dev.parent, bmsr, lpa,
182 					   status, state);
183 }
184 
185 static int marvell_c22_pcs_config(struct phylink_pcs *pcs,
186 				  unsigned int neg_mode,
187 				  phy_interface_t interface,
188 				  const unsigned long *advertising,
189 				  bool permit_pause_to_mac)
190 {
191 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
192 	int oldpage, adv, err, ret = 0;
193 	u16 bmcr;
194 
195 	adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
196 	if (adv < 0)
197 		return 0;
198 
199 	bmcr = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED ? BMCR_ANENABLE : 0;
200 
201 	oldpage = marvell_c22_pcs_set_fiber_page(mpcs);
202 	if (oldpage < 0)
203 		goto restore;
204 
205 	err = __mdiodev_modify_changed(&mpcs->mdio, MII_ADVERTISE, 0xffff, adv);
206 	ret = err;
207 	if (err < 0)
208 		goto restore;
209 
210 	err = __mdiodev_modify_changed(&mpcs->mdio, MII_BMCR, BMCR_ANENABLE,
211 				       bmcr);
212 	if (err < 0) {
213 		ret = err;
214 		goto restore;
215 	}
216 
217 	/* If the ANENABLE bit was changed, the PHY will restart negotiation,
218 	 * so we don't need to flag a change to trigger its own restart.
219 	 */
220 	if (err)
221 		ret = 0;
222 
223 restore:
224 	return marvell_c22_pcs_restore_page(mpcs, oldpage, ret);
225 }
226 
227 static void marvell_c22_pcs_an_restart(struct phylink_pcs *pcs)
228 {
229 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
230 
231 	marvell_c22_pcs_modify(mpcs, MII_BMCR, BMCR_ANRESTART, BMCR_ANRESTART);
232 }
233 
234 static void marvell_c22_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
235 				    phy_interface_t interface, int speed,
236 				    int duplex)
237 {
238 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
239 	u16 bmcr;
240 	int err;
241 
242 	if (phylink_autoneg_inband(mode))
243 		return;
244 
245 	bmcr = mii_bmcr_encode_fixed(speed, duplex);
246 
247 	err = marvell_c22_pcs_modify(mpcs, MII_BMCR, BMCR_SPEED100 |
248 				     BMCR_FULLDPLX | BMCR_SPEED1000, bmcr);
249 	if (err)
250 		dev_err(mpcs->mdio.dev.parent,
251 			"%s: failed to configure mpcs: %pe\n", mpcs->name,
252 			ERR_PTR(err));
253 }
254 
255 static const struct phylink_pcs_ops marvell_c22_pcs_ops = {
256 	.pcs_enable = marvell_c22_pcs_enable,
257 	.pcs_disable = marvell_c22_pcs_disable,
258 	.pcs_get_state = marvell_c22_pcs_get_state,
259 	.pcs_config = marvell_c22_pcs_config,
260 	.pcs_an_restart = marvell_c22_pcs_an_restart,
261 	.pcs_link_up = marvell_c22_pcs_link_up,
262 };
263 
264 static struct marvell_c22_pcs *marvell_c22_pcs_alloc(struct device *dev,
265 						     struct mii_bus *bus,
266 						     unsigned int addr)
267 {
268 	struct marvell_c22_pcs *mpcs;
269 
270 	mpcs = kzalloc(sizeof(*mpcs), GFP_KERNEL);
271 	if (!mpcs)
272 		return NULL;
273 
274 	mpcs->mdio.dev.parent = dev;
275 	mpcs->mdio.bus = bus;
276 	mpcs->mdio.addr = addr;
277 	mpcs->phylink_pcs.ops = &marvell_c22_pcs_ops;
278 	mpcs->phylink_pcs.neg_mode = true;
279 
280 	return mpcs;
281 }
282 
283 static int marvell_c22_pcs_setup_irq(struct marvell_c22_pcs *mpcs,
284 				     unsigned int irq)
285 {
286 	int err;
287 
288 	mpcs->phylink_pcs.poll = !irq;
289 	mpcs->irq = irq;
290 
291 	if (irq) {
292 		err = request_threaded_irq(irq, NULL,
293 					   marvell_c22_pcs_handle_irq,
294 					   IRQF_ONESHOT, mpcs->name, mpcs);
295 		if (err)
296 			return err;
297 	}
298 
299 	return 0;
300 }
301 
302 /* mv88e6352 specifics */
303 
304 static bool mv88e6352_pcs_link_check(struct marvell_c22_pcs *mpcs)
305 {
306 	struct mv88e6xxx_port *port = mpcs->port;
307 	struct mv88e6xxx_chip *chip = port->chip;
308 	u8 cmode;
309 
310 	/* Port 4 can be in auto-media mode. Check that the port is
311 	 * associated with the mpcs.
312 	 */
313 	mv88e6xxx_reg_lock(chip);
314 	chip->info->ops->port_get_cmode(chip, port->port, &cmode);
315 	mv88e6xxx_reg_unlock(chip);
316 
317 	return cmode == MV88E6XXX_PORT_STS_CMODE_100BASEX ||
318 	       cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
319 	       cmode == MV88E6XXX_PORT_STS_CMODE_SGMII;
320 }
321 
322 static int mv88e6352_pcs_init(struct mv88e6xxx_chip *chip, int port)
323 {
324 	struct marvell_c22_pcs *mpcs;
325 	struct mii_bus *bus;
326 	struct device *dev;
327 	unsigned int irq;
328 	int err;
329 
330 	mv88e6xxx_reg_lock(chip);
331 	err = mv88e6352_g2_scratch_port_has_serdes(chip, port);
332 	mv88e6xxx_reg_unlock(chip);
333 	if (err <= 0)
334 		return err;
335 
336 	irq = mv88e6xxx_serdes_irq_mapping(chip, port);
337 	bus = mv88e6xxx_default_mdio_bus(chip);
338 	dev = chip->dev;
339 
340 	mpcs = marvell_c22_pcs_alloc(dev, bus, MV88E6352_ADDR_SERDES);
341 	if (!mpcs)
342 		return -ENOMEM;
343 
344 	snprintf(mpcs->name, sizeof(mpcs->name),
345 		 "mv88e6xxx-%s-serdes-%d", dev_name(dev), port);
346 
347 	mpcs->link_check = mv88e6352_pcs_link_check;
348 	mpcs->port = &chip->ports[port];
349 
350 	err = marvell_c22_pcs_setup_irq(mpcs, irq);
351 	if (err) {
352 		kfree(mpcs);
353 		return err;
354 	}
355 
356 	chip->ports[port].pcs_private = &mpcs->phylink_pcs;
357 
358 	return 0;
359 }
360 
361 static void mv88e6352_pcs_teardown(struct mv88e6xxx_chip *chip, int port)
362 {
363 	struct marvell_c22_pcs *mpcs;
364 	struct phylink_pcs *pcs;
365 
366 	pcs = chip->ports[port].pcs_private;
367 	if (!pcs)
368 		return;
369 
370 	mpcs = pcs_to_marvell_c22_pcs(pcs);
371 
372 	if (mpcs->irq)
373 		free_irq(mpcs->irq, mpcs);
374 
375 	kfree(mpcs);
376 
377 	chip->ports[port].pcs_private = NULL;
378 }
379 
380 static struct phylink_pcs *mv88e6352_pcs_select(struct mv88e6xxx_chip *chip,
381 						int port,
382 						phy_interface_t interface)
383 {
384 	return chip->ports[port].pcs_private;
385 }
386 
387 const struct mv88e6xxx_pcs_ops mv88e6352_pcs_ops = {
388 	.pcs_init = mv88e6352_pcs_init,
389 	.pcs_teardown = mv88e6352_pcs_teardown,
390 	.pcs_select = mv88e6352_pcs_select,
391 };
392