xref: /linux/drivers/net/dsa/mv88e6xxx/pcs-6352.c (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
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 				      struct phylink_link_state *state)
162 {
163 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
164 	int oldpage, bmsr, lpa, status;
165 
166 	state->link = false;
167 
168 	if (mpcs->link_check && !mpcs->link_check(mpcs))
169 		return;
170 
171 	oldpage = marvell_c22_pcs_set_fiber_page(mpcs);
172 	if (oldpage >= 0) {
173 		bmsr = __mdiodev_read(&mpcs->mdio, MII_BMSR);
174 		lpa = __mdiodev_read(&mpcs->mdio, MII_LPA);
175 		status = __mdiodev_read(&mpcs->mdio, MII_M1011_PHY_STATUS);
176 	}
177 
178 	if (marvell_c22_pcs_restore_page(mpcs, oldpage, 0) >= 0 &&
179 	    bmsr >= 0 && lpa >= 0 && status >= 0)
180 		mv88e6xxx_pcs_decode_state(mpcs->mdio.dev.parent, bmsr, lpa,
181 					   status, state);
182 }
183 
184 static int marvell_c22_pcs_config(struct phylink_pcs *pcs,
185 				  unsigned int neg_mode,
186 				  phy_interface_t interface,
187 				  const unsigned long *advertising,
188 				  bool permit_pause_to_mac)
189 {
190 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
191 	int oldpage, adv, err, ret = 0;
192 	u16 bmcr;
193 
194 	adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
195 	if (adv < 0)
196 		return 0;
197 
198 	bmcr = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED ? BMCR_ANENABLE : 0;
199 
200 	oldpage = marvell_c22_pcs_set_fiber_page(mpcs);
201 	if (oldpage < 0)
202 		goto restore;
203 
204 	err = __mdiodev_modify_changed(&mpcs->mdio, MII_ADVERTISE, 0xffff, adv);
205 	ret = err;
206 	if (err < 0)
207 		goto restore;
208 
209 	err = __mdiodev_modify_changed(&mpcs->mdio, MII_BMCR, BMCR_ANENABLE,
210 				       bmcr);
211 	if (err < 0) {
212 		ret = err;
213 		goto restore;
214 	}
215 
216 	/* If the ANENABLE bit was changed, the PHY will restart negotiation,
217 	 * so we don't need to flag a change to trigger its own restart.
218 	 */
219 	if (err)
220 		ret = 0;
221 
222 restore:
223 	return marvell_c22_pcs_restore_page(mpcs, oldpage, ret);
224 }
225 
226 static void marvell_c22_pcs_an_restart(struct phylink_pcs *pcs)
227 {
228 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
229 
230 	marvell_c22_pcs_modify(mpcs, MII_BMCR, BMCR_ANRESTART, BMCR_ANRESTART);
231 }
232 
233 static void marvell_c22_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
234 				    phy_interface_t interface, int speed,
235 				    int duplex)
236 {
237 	struct marvell_c22_pcs *mpcs = pcs_to_marvell_c22_pcs(pcs);
238 	u16 bmcr;
239 	int err;
240 
241 	if (phylink_autoneg_inband(mode))
242 		return;
243 
244 	bmcr = mii_bmcr_encode_fixed(speed, duplex);
245 
246 	err = marvell_c22_pcs_modify(mpcs, MII_BMCR, BMCR_SPEED100 |
247 				     BMCR_FULLDPLX | BMCR_SPEED1000, bmcr);
248 	if (err)
249 		dev_err(mpcs->mdio.dev.parent,
250 			"%s: failed to configure mpcs: %pe\n", mpcs->name,
251 			ERR_PTR(err));
252 }
253 
254 static const struct phylink_pcs_ops marvell_c22_pcs_ops = {
255 	.pcs_enable = marvell_c22_pcs_enable,
256 	.pcs_disable = marvell_c22_pcs_disable,
257 	.pcs_get_state = marvell_c22_pcs_get_state,
258 	.pcs_config = marvell_c22_pcs_config,
259 	.pcs_an_restart = marvell_c22_pcs_an_restart,
260 	.pcs_link_up = marvell_c22_pcs_link_up,
261 };
262 
263 static struct marvell_c22_pcs *marvell_c22_pcs_alloc(struct device *dev,
264 						     struct mii_bus *bus,
265 						     unsigned int addr)
266 {
267 	struct marvell_c22_pcs *mpcs;
268 
269 	mpcs = kzalloc(sizeof(*mpcs), GFP_KERNEL);
270 	if (!mpcs)
271 		return NULL;
272 
273 	mpcs->mdio.dev.parent = dev;
274 	mpcs->mdio.bus = bus;
275 	mpcs->mdio.addr = addr;
276 	mpcs->phylink_pcs.ops = &marvell_c22_pcs_ops;
277 	mpcs->phylink_pcs.neg_mode = true;
278 
279 	return mpcs;
280 }
281 
282 static int marvell_c22_pcs_setup_irq(struct marvell_c22_pcs *mpcs,
283 				     unsigned int irq)
284 {
285 	int err;
286 
287 	mpcs->phylink_pcs.poll = !irq;
288 	mpcs->irq = irq;
289 
290 	if (irq) {
291 		err = request_threaded_irq(irq, NULL,
292 					   marvell_c22_pcs_handle_irq,
293 					   IRQF_ONESHOT, mpcs->name, mpcs);
294 		if (err)
295 			return err;
296 	}
297 
298 	return 0;
299 }
300 
301 /* mv88e6352 specifics */
302 
303 static bool mv88e6352_pcs_link_check(struct marvell_c22_pcs *mpcs)
304 {
305 	struct mv88e6xxx_port *port = mpcs->port;
306 	struct mv88e6xxx_chip *chip = port->chip;
307 	u8 cmode;
308 
309 	/* Port 4 can be in auto-media mode. Check that the port is
310 	 * associated with the mpcs.
311 	 */
312 	mv88e6xxx_reg_lock(chip);
313 	chip->info->ops->port_get_cmode(chip, port->port, &cmode);
314 	mv88e6xxx_reg_unlock(chip);
315 
316 	return cmode == MV88E6XXX_PORT_STS_CMODE_100BASEX ||
317 	       cmode == MV88E6XXX_PORT_STS_CMODE_1000BASEX ||
318 	       cmode == MV88E6XXX_PORT_STS_CMODE_SGMII;
319 }
320 
321 static int mv88e6352_pcs_init(struct mv88e6xxx_chip *chip, int port)
322 {
323 	struct marvell_c22_pcs *mpcs;
324 	struct mii_bus *bus;
325 	struct device *dev;
326 	unsigned int irq;
327 	int err;
328 
329 	mv88e6xxx_reg_lock(chip);
330 	err = mv88e6352_g2_scratch_port_has_serdes(chip, port);
331 	mv88e6xxx_reg_unlock(chip);
332 	if (err <= 0)
333 		return err;
334 
335 	irq = mv88e6xxx_serdes_irq_mapping(chip, port);
336 	bus = mv88e6xxx_default_mdio_bus(chip);
337 	dev = chip->dev;
338 
339 	mpcs = marvell_c22_pcs_alloc(dev, bus, MV88E6352_ADDR_SERDES);
340 	if (!mpcs)
341 		return -ENOMEM;
342 
343 	snprintf(mpcs->name, sizeof(mpcs->name),
344 		 "mv88e6xxx-%s-serdes-%d", dev_name(dev), port);
345 
346 	mpcs->link_check = mv88e6352_pcs_link_check;
347 	mpcs->port = &chip->ports[port];
348 
349 	err = marvell_c22_pcs_setup_irq(mpcs, irq);
350 	if (err) {
351 		kfree(mpcs);
352 		return err;
353 	}
354 
355 	chip->ports[port].pcs_private = &mpcs->phylink_pcs;
356 
357 	return 0;
358 }
359 
360 static void mv88e6352_pcs_teardown(struct mv88e6xxx_chip *chip, int port)
361 {
362 	struct marvell_c22_pcs *mpcs;
363 	struct phylink_pcs *pcs;
364 
365 	pcs = chip->ports[port].pcs_private;
366 	if (!pcs)
367 		return;
368 
369 	mpcs = pcs_to_marvell_c22_pcs(pcs);
370 
371 	if (mpcs->irq)
372 		free_irq(mpcs->irq, mpcs);
373 
374 	kfree(mpcs);
375 
376 	chip->ports[port].pcs_private = NULL;
377 }
378 
379 static struct phylink_pcs *mv88e6352_pcs_select(struct mv88e6xxx_chip *chip,
380 						int port,
381 						phy_interface_t interface)
382 {
383 	return chip->ports[port].pcs_private;
384 }
385 
386 const struct mv88e6xxx_pcs_ops mv88e6352_pcs_ops = {
387 	.pcs_init = mv88e6352_pcs_init,
388 	.pcs_teardown = mv88e6352_pcs_teardown,
389 	.pcs_select = mv88e6352_pcs_select,
390 };
391