xref: /linux/drivers/net/pcs/pcs-mtk-lynxi.c (revision a34b0e4e21d6be3c3d620aa7f9dfbf0e9550c19e)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2018-2019 MediaTek Inc.
3 /* A library for MediaTek SGMII circuit
4  *
5  * Author: Sean Wang <sean.wang@mediatek.com>
6  * Author: Alexander Couzens <lynxis@fe80.eu>
7  * Author: Daniel Golle <daniel@makrotopia.org>
8  *
9  */
10 
11 #include <linux/mdio.h>
12 #include <linux/of.h>
13 #include <linux/pcs/pcs-mtk-lynxi.h>
14 #include <linux/phy/phy-common-props.h>
15 #include <linux/phylink.h>
16 #include <linux/regmap.h>
17 
18 /* SGMII subsystem config registers */
19 /* BMCR (low 16) BMSR (high 16) */
20 #define SGMSYS_PCS_CONTROL_1		0x0
21 #define SGMII_BMCR			GENMASK(15, 0)
22 #define SGMII_BMSR			GENMASK(31, 16)
23 
24 #define SGMSYS_PCS_DEVICE_ID		0x4
25 #define SGMII_LYNXI_DEV_ID		0x4d544950
26 
27 #define SGMSYS_PCS_ADVERTISE		0x8
28 #define SGMII_ADVERTISE			GENMASK(15, 0)
29 #define SGMII_LPA			GENMASK(31, 16)
30 
31 #define SGMSYS_PCS_SCRATCH		0x14
32 #define SGMII_DEV_VERSION		GENMASK(31, 16)
33 
34 /* Register to programmable link timer, the unit in 2 * 8ns */
35 #define SGMSYS_PCS_LINK_TIMER		0x18
36 #define SGMII_LINK_TIMER_MASK		GENMASK(19, 0)
37 #define SGMII_LINK_TIMER_VAL(ns)	FIELD_PREP(SGMII_LINK_TIMER_MASK, \
38 						   ((ns) / 2 / 8))
39 
40 /* Register to control remote fault */
41 #define SGMSYS_SGMII_MODE		0x20
42 #define SGMII_IF_MODE_SGMII		BIT(0)
43 #define SGMII_SPEED_DUPLEX_AN		BIT(1)
44 #define SGMII_SPEED_MASK		GENMASK(3, 2)
45 #define SGMII_SPEED_10			FIELD_PREP(SGMII_SPEED_MASK, 0)
46 #define SGMII_SPEED_100			FIELD_PREP(SGMII_SPEED_MASK, 1)
47 #define SGMII_SPEED_1000		FIELD_PREP(SGMII_SPEED_MASK, 2)
48 #define SGMII_DUPLEX_HALF		BIT(4)
49 #define SGMII_REMOTE_FAULT_DIS		BIT(8)
50 
51 /* Register to reset SGMII design */
52 #define SGMSYS_RESERVED_0		0x34
53 #define SGMII_SW_RESET			BIT(0)
54 
55 /* Register to set SGMII speed, ANA RG_ Control Signals III */
56 #define SGMII_PHY_SPEED_MASK		GENMASK(3, 2)
57 #define SGMII_PHY_SPEED_1_25G		FIELD_PREP(SGMII_PHY_SPEED_MASK, 0)
58 #define SGMII_PHY_SPEED_3_125G		FIELD_PREP(SGMII_PHY_SPEED_MASK, 1)
59 
60 /* Register to power up QPHY */
61 #define SGMSYS_QPHY_PWR_STATE_CTRL	0xe8
62 #define	SGMII_PHYA_PWD			BIT(4)
63 
64 /* Register to QPHY wrapper control */
65 #define SGMSYS_QPHY_WRAP_CTRL		0xec
66 #define SGMII_PN_SWAP_RX		BIT(1)
67 #define SGMII_PN_SWAP_TX		BIT(0)
68 
69 
70 /* struct mtk_pcs_lynxi -  This structure holds each sgmii regmap andassociated
71  *                         data
72  * @regmap:                The register map pointing at the range used to setup
73  *                         SGMII modes
74  * @dev:                   Pointer to device owning the PCS
75  * @ana_rgc3:              The offset of register ANA_RGC3 relative to regmap
76  * @interface:             Currently configured interface mode
77  * @pcs:                   Phylink PCS structure
78  * @flags:                 Flags indicating hardware properties
79  */
80 struct mtk_pcs_lynxi {
81 	struct regmap		*regmap;
82 	u32			ana_rgc3;
83 	phy_interface_t		interface;
84 	struct			phylink_pcs pcs;
85 	u32			flags;
86 	struct fwnode_handle	*fwnode;
87 };
88 
89 static struct mtk_pcs_lynxi *pcs_to_mtk_pcs_lynxi(struct phylink_pcs *pcs)
90 {
91 	return container_of(pcs, struct mtk_pcs_lynxi, pcs);
92 }
93 
94 static unsigned int mtk_pcs_lynxi_inband_caps(struct phylink_pcs *pcs,
95 					      phy_interface_t interface)
96 {
97 	switch (interface) {
98 	case PHY_INTERFACE_MODE_1000BASEX:
99 	case PHY_INTERFACE_MODE_2500BASEX:
100 	case PHY_INTERFACE_MODE_SGMII:
101 		return LINK_INBAND_DISABLE | LINK_INBAND_ENABLE;
102 
103 	default:
104 		return 0;
105 	}
106 }
107 
108 static void mtk_pcs_lynxi_get_state(struct phylink_pcs *pcs,
109 				    unsigned int neg_mode,
110 				    struct phylink_link_state *state)
111 {
112 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
113 	unsigned int bm, adv;
114 
115 	/* Read the BMSR and LPA */
116 	regmap_read(mpcs->regmap, SGMSYS_PCS_CONTROL_1, &bm);
117 	regmap_read(mpcs->regmap, SGMSYS_PCS_ADVERTISE, &adv);
118 
119 	phylink_mii_c22_pcs_decode_state(state, neg_mode,
120 					 FIELD_GET(SGMII_BMSR, bm),
121 					 FIELD_GET(SGMII_LPA, adv));
122 }
123 
124 static int mtk_pcs_config_polarity(struct mtk_pcs_lynxi *mpcs,
125 				   phy_interface_t interface)
126 {
127 	struct fwnode_handle *fwnode = mpcs->fwnode, *pcs_fwnode;
128 	unsigned int pol, default_pol = PHY_POL_NORMAL;
129 	unsigned int val = 0;
130 	int ret;
131 
132 	if (fwnode_property_read_bool(fwnode, "mediatek,pnswap"))
133 		default_pol = PHY_POL_INVERT;
134 
135 	pcs_fwnode = fwnode_get_named_child_node(fwnode, "pcs");
136 
137 	ret = phy_get_rx_polarity(pcs_fwnode, phy_modes(interface),
138 				  BIT(PHY_POL_NORMAL) | BIT(PHY_POL_INVERT),
139 				  default_pol, &pol);
140 	if (ret) {
141 		fwnode_handle_put(pcs_fwnode);
142 		return ret;
143 	}
144 	if (pol == PHY_POL_INVERT)
145 		val |= SGMII_PN_SWAP_RX;
146 
147 	ret = phy_get_tx_polarity(pcs_fwnode, phy_modes(interface),
148 				  BIT(PHY_POL_NORMAL) | BIT(PHY_POL_INVERT),
149 				  default_pol, &pol);
150 	fwnode_handle_put(pcs_fwnode);
151 	if (ret)
152 		return ret;
153 	if (pol == PHY_POL_INVERT)
154 		val |= SGMII_PN_SWAP_TX;
155 
156 	return regmap_update_bits(mpcs->regmap, SGMSYS_QPHY_WRAP_CTRL,
157 				  SGMII_PN_SWAP_RX | SGMII_PN_SWAP_TX, val);
158 }
159 
160 static int mtk_pcs_lynxi_config(struct phylink_pcs *pcs, unsigned int neg_mode,
161 				phy_interface_t interface,
162 				const unsigned long *advertising,
163 				bool permit_pause_to_mac)
164 {
165 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
166 	bool mode_changed = false, changed;
167 	unsigned int rgc3, sgm_mode, bmcr;
168 	int advertise, link_timer;
169 	int ret;
170 
171 	advertise = phylink_mii_c22_pcs_encode_advertisement(interface,
172 							     advertising);
173 	if (advertise < 0)
174 		return advertise;
175 
176 	/* Clearing IF_MODE_BIT0 switches the PCS to BASE-X mode, and
177 	 * we assume that fixes it's speed at bitrate = line rate (in
178 	 * other words, 1000Mbps or 2500Mbps).
179 	 */
180 	if (interface == PHY_INTERFACE_MODE_SGMII)
181 		sgm_mode = SGMII_IF_MODE_SGMII;
182 	else
183 		sgm_mode = 0;
184 
185 	if (neg_mode & PHYLINK_PCS_NEG_INBAND)
186 		sgm_mode |= SGMII_REMOTE_FAULT_DIS;
187 
188 	if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
189 		if (interface == PHY_INTERFACE_MODE_SGMII)
190 			sgm_mode |= SGMII_SPEED_DUPLEX_AN;
191 		bmcr = BMCR_ANENABLE;
192 	} else {
193 		bmcr = 0;
194 	}
195 
196 	if (mpcs->interface != interface) {
197 		link_timer = phylink_get_link_timer_ns(interface);
198 		if (link_timer < 0)
199 			return link_timer;
200 
201 		/* PHYA power down */
202 		regmap_set_bits(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL,
203 				SGMII_PHYA_PWD);
204 
205 		/* Reset SGMII PCS state */
206 		regmap_set_bits(mpcs->regmap, SGMSYS_RESERVED_0,
207 				SGMII_SW_RESET);
208 
209 		ret = mtk_pcs_config_polarity(mpcs, interface);
210 		if (ret)
211 			return ret;
212 
213 		if (interface == PHY_INTERFACE_MODE_2500BASEX)
214 			rgc3 = SGMII_PHY_SPEED_3_125G;
215 		else
216 			rgc3 = SGMII_PHY_SPEED_1_25G;
217 
218 		/* Configure the underlying interface speed */
219 		regmap_update_bits(mpcs->regmap, mpcs->ana_rgc3,
220 				   SGMII_PHY_SPEED_MASK, rgc3);
221 
222 		/* Setup the link timer */
223 		regmap_write(mpcs->regmap, SGMSYS_PCS_LINK_TIMER,
224 			     SGMII_LINK_TIMER_VAL(link_timer));
225 
226 		mpcs->interface = interface;
227 		mode_changed = true;
228 	}
229 
230 	/* Update the advertisement, noting whether it has changed */
231 	regmap_update_bits_check(mpcs->regmap, SGMSYS_PCS_ADVERTISE,
232 				 SGMII_ADVERTISE, advertise, &changed);
233 
234 	/* Update the sgmsys mode register */
235 	regmap_update_bits(mpcs->regmap, SGMSYS_SGMII_MODE,
236 			   SGMII_REMOTE_FAULT_DIS | SGMII_SPEED_DUPLEX_AN |
237 			   SGMII_IF_MODE_SGMII, sgm_mode);
238 
239 	/* Update the BMCR */
240 	regmap_update_bits(mpcs->regmap, SGMSYS_PCS_CONTROL_1,
241 			   BMCR_ANENABLE, bmcr);
242 
243 	/* Release PHYA power down state
244 	 * Only removing bit SGMII_PHYA_PWD isn't enough.
245 	 * There are cases when the SGMII_PHYA_PWD register contains 0x9 which
246 	 * prevents SGMII from working. The SGMII still shows link but no traffic
247 	 * can flow. Writing 0x0 to the PHYA_PWD register fix the issue. 0x0 was
248 	 * taken from a good working state of the SGMII interface.
249 	 * Unknown how much the QPHY needs but it is racy without a sleep.
250 	 * Tested on mt7622 & mt7986.
251 	 */
252 	usleep_range(50, 100);
253 	regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, 0);
254 
255 	return changed || mode_changed;
256 }
257 
258 static void mtk_pcs_lynxi_restart_an(struct phylink_pcs *pcs)
259 {
260 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
261 
262 	regmap_set_bits(mpcs->regmap, SGMSYS_PCS_CONTROL_1, BMCR_ANRESTART);
263 }
264 
265 static void mtk_pcs_lynxi_link_up(struct phylink_pcs *pcs,
266 				  unsigned int neg_mode,
267 				  phy_interface_t interface, int speed,
268 				  int duplex)
269 {
270 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
271 	unsigned int sgm_mode;
272 
273 	if (neg_mode != PHYLINK_PCS_NEG_INBAND_ENABLED) {
274 		/* Force the speed and duplex setting */
275 		if (speed == SPEED_10)
276 			sgm_mode = SGMII_SPEED_10;
277 		else if (speed == SPEED_100)
278 			sgm_mode = SGMII_SPEED_100;
279 		else
280 			sgm_mode = SGMII_SPEED_1000;
281 
282 		if (duplex != DUPLEX_FULL)
283 			sgm_mode |= SGMII_DUPLEX_HALF;
284 
285 		regmap_update_bits(mpcs->regmap, SGMSYS_SGMII_MODE,
286 				   SGMII_DUPLEX_HALF | SGMII_SPEED_MASK,
287 				   sgm_mode);
288 	}
289 }
290 
291 static void mtk_pcs_lynxi_disable(struct phylink_pcs *pcs)
292 {
293 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
294 
295 	mpcs->interface = PHY_INTERFACE_MODE_NA;
296 }
297 
298 static const struct phylink_pcs_ops mtk_pcs_lynxi_ops = {
299 	.pcs_inband_caps = mtk_pcs_lynxi_inband_caps,
300 	.pcs_get_state = mtk_pcs_lynxi_get_state,
301 	.pcs_config = mtk_pcs_lynxi_config,
302 	.pcs_an_restart = mtk_pcs_lynxi_restart_an,
303 	.pcs_link_up = mtk_pcs_lynxi_link_up,
304 	.pcs_disable = mtk_pcs_lynxi_disable,
305 };
306 
307 struct phylink_pcs *mtk_pcs_lynxi_create(struct device *dev,
308 					 struct fwnode_handle *fwnode,
309 					 struct regmap *regmap, u32 ana_rgc3)
310 {
311 	struct mtk_pcs_lynxi *mpcs;
312 	u32 id, ver;
313 	int ret;
314 
315 	ret = regmap_read(regmap, SGMSYS_PCS_DEVICE_ID, &id);
316 	if (ret < 0)
317 		return NULL;
318 
319 	if (id != SGMII_LYNXI_DEV_ID) {
320 		dev_err(dev, "unknown PCS device id %08x\n", id);
321 		return NULL;
322 	}
323 
324 	ret = regmap_read(regmap, SGMSYS_PCS_SCRATCH, &ver);
325 	if (ret < 0)
326 		return NULL;
327 
328 	ver = FIELD_GET(SGMII_DEV_VERSION, ver);
329 	if (ver != 0x1) {
330 		dev_err(dev, "unknown PCS device version %04x\n", ver);
331 		return NULL;
332 	}
333 
334 	dev_dbg(dev, "MediaTek LynxI SGMII PCS (id 0x%08x, ver 0x%04x)\n", id,
335 		ver);
336 
337 	mpcs = kzalloc(sizeof(*mpcs), GFP_KERNEL);
338 	if (!mpcs)
339 		return NULL;
340 
341 	mpcs->ana_rgc3 = ana_rgc3;
342 	mpcs->regmap = regmap;
343 	mpcs->pcs.ops = &mtk_pcs_lynxi_ops;
344 	mpcs->pcs.poll = true;
345 	mpcs->interface = PHY_INTERFACE_MODE_NA;
346 	mpcs->fwnode = fwnode_handle_get(fwnode);
347 
348 	__set_bit(PHY_INTERFACE_MODE_SGMII, mpcs->pcs.supported_interfaces);
349 	__set_bit(PHY_INTERFACE_MODE_1000BASEX, mpcs->pcs.supported_interfaces);
350 	__set_bit(PHY_INTERFACE_MODE_2500BASEX, mpcs->pcs.supported_interfaces);
351 
352 	return &mpcs->pcs;
353 }
354 EXPORT_SYMBOL(mtk_pcs_lynxi_create);
355 
356 void mtk_pcs_lynxi_destroy(struct phylink_pcs *pcs)
357 {
358 	struct mtk_pcs_lynxi *mpcs;
359 
360 	if (!pcs)
361 		return;
362 
363 	mpcs = pcs_to_mtk_pcs_lynxi(pcs);
364 	fwnode_handle_put(mpcs->fwnode);
365 	kfree(mpcs);
366 }
367 EXPORT_SYMBOL(mtk_pcs_lynxi_destroy);
368 
369 MODULE_DESCRIPTION("MediaTek SGMII library for LynxI");
370 MODULE_LICENSE("GPL");
371