xref: /linux/drivers/net/pcs/pcs-mtk-lynxi.c (revision 816b02e63a759c4458edee142b721ab09c918b3d)
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/phylink.h>
15 #include <linux/regmap.h>
16 
17 /* SGMII subsystem config registers */
18 /* BMCR (low 16) BMSR (high 16) */
19 #define SGMSYS_PCS_CONTROL_1		0x0
20 #define SGMII_BMCR			GENMASK(15, 0)
21 #define SGMII_BMSR			GENMASK(31, 16)
22 
23 #define SGMSYS_PCS_DEVICE_ID		0x4
24 #define SGMII_LYNXI_DEV_ID		0x4d544950
25 
26 #define SGMSYS_PCS_ADVERTISE		0x8
27 #define SGMII_ADVERTISE			GENMASK(15, 0)
28 #define SGMII_LPA			GENMASK(31, 16)
29 
30 #define SGMSYS_PCS_SCRATCH		0x14
31 #define SGMII_DEV_VERSION		GENMASK(31, 16)
32 
33 /* Register to programmable link timer, the unit in 2 * 8ns */
34 #define SGMSYS_PCS_LINK_TIMER		0x18
35 #define SGMII_LINK_TIMER_MASK		GENMASK(19, 0)
36 #define SGMII_LINK_TIMER_VAL(ns)	FIELD_PREP(SGMII_LINK_TIMER_MASK, \
37 						   ((ns) / 2 / 8))
38 
39 /* Register to control remote fault */
40 #define SGMSYS_SGMII_MODE		0x20
41 #define SGMII_IF_MODE_SGMII		BIT(0)
42 #define SGMII_SPEED_DUPLEX_AN		BIT(1)
43 #define SGMII_SPEED_MASK		GENMASK(3, 2)
44 #define SGMII_SPEED_10			FIELD_PREP(SGMII_SPEED_MASK, 0)
45 #define SGMII_SPEED_100			FIELD_PREP(SGMII_SPEED_MASK, 1)
46 #define SGMII_SPEED_1000		FIELD_PREP(SGMII_SPEED_MASK, 2)
47 #define SGMII_DUPLEX_HALF		BIT(4)
48 #define SGMII_REMOTE_FAULT_DIS		BIT(8)
49 
50 /* Register to reset SGMII design */
51 #define SGMSYS_RESERVED_0		0x34
52 #define SGMII_SW_RESET			BIT(0)
53 
54 /* Register to set SGMII speed, ANA RG_ Control Signals III */
55 #define SGMII_PHY_SPEED_MASK		GENMASK(3, 2)
56 #define SGMII_PHY_SPEED_1_25G		FIELD_PREP(SGMII_PHY_SPEED_MASK, 0)
57 #define SGMII_PHY_SPEED_3_125G		FIELD_PREP(SGMII_PHY_SPEED_MASK, 1)
58 
59 /* Register to power up QPHY */
60 #define SGMSYS_QPHY_PWR_STATE_CTRL	0xe8
61 #define	SGMII_PHYA_PWD			BIT(4)
62 
63 /* Register to QPHY wrapper control */
64 #define SGMSYS_QPHY_WRAP_CTRL		0xec
65 #define SGMII_PN_SWAP_MASK		GENMASK(1, 0)
66 #define SGMII_PN_SWAP_TX_RX		(BIT(0) | BIT(1))
67 
68 /* struct mtk_pcs_lynxi -  This structure holds each sgmii regmap andassociated
69  *                         data
70  * @regmap:                The register map pointing at the range used to setup
71  *                         SGMII modes
72  * @dev:                   Pointer to device owning the PCS
73  * @ana_rgc3:              The offset of register ANA_RGC3 relative to regmap
74  * @interface:             Currently configured interface mode
75  * @pcs:                   Phylink PCS structure
76  * @flags:                 Flags indicating hardware properties
77  */
78 struct mtk_pcs_lynxi {
79 	struct regmap		*regmap;
80 	u32			ana_rgc3;
81 	phy_interface_t		interface;
82 	struct			phylink_pcs pcs;
83 	u32			flags;
84 };
85 
86 static struct mtk_pcs_lynxi *pcs_to_mtk_pcs_lynxi(struct phylink_pcs *pcs)
87 {
88 	return container_of(pcs, struct mtk_pcs_lynxi, pcs);
89 }
90 
91 static unsigned int mtk_pcs_lynxi_inband_caps(struct phylink_pcs *pcs,
92 					      phy_interface_t interface)
93 {
94 	switch (interface) {
95 	case PHY_INTERFACE_MODE_1000BASEX:
96 	case PHY_INTERFACE_MODE_SGMII:
97 		return LINK_INBAND_DISABLE | LINK_INBAND_ENABLE;
98 
99 	case PHY_INTERFACE_MODE_2500BASEX:
100 		return LINK_INBAND_DISABLE;
101 
102 	default:
103 		return 0;
104 	}
105 }
106 
107 static void mtk_pcs_lynxi_get_state(struct phylink_pcs *pcs,
108 				    struct phylink_link_state *state)
109 {
110 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
111 	unsigned int bm, adv;
112 
113 	/* Read the BMSR and LPA */
114 	regmap_read(mpcs->regmap, SGMSYS_PCS_CONTROL_1, &bm);
115 	regmap_read(mpcs->regmap, SGMSYS_PCS_ADVERTISE, &adv);
116 
117 	phylink_mii_c22_pcs_decode_state(state, FIELD_GET(SGMII_BMSR, bm),
118 					 FIELD_GET(SGMII_LPA, adv));
119 }
120 
121 static int mtk_pcs_lynxi_config(struct phylink_pcs *pcs, unsigned int neg_mode,
122 				phy_interface_t interface,
123 				const unsigned long *advertising,
124 				bool permit_pause_to_mac)
125 {
126 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
127 	bool mode_changed = false, changed;
128 	unsigned int rgc3, sgm_mode, bmcr;
129 	int advertise, link_timer;
130 
131 	advertise = phylink_mii_c22_pcs_encode_advertisement(interface,
132 							     advertising);
133 	if (advertise < 0)
134 		return advertise;
135 
136 	/* Clearing IF_MODE_BIT0 switches the PCS to BASE-X mode, and
137 	 * we assume that fixes it's speed at bitrate = line rate (in
138 	 * other words, 1000Mbps or 2500Mbps).
139 	 */
140 	if (interface == PHY_INTERFACE_MODE_SGMII)
141 		sgm_mode = SGMII_IF_MODE_SGMII;
142 	else
143 		sgm_mode = 0;
144 
145 	if (neg_mode & PHYLINK_PCS_NEG_INBAND)
146 		sgm_mode |= SGMII_REMOTE_FAULT_DIS;
147 
148 	if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
149 		if (interface == PHY_INTERFACE_MODE_SGMII)
150 			sgm_mode |= SGMII_SPEED_DUPLEX_AN;
151 		bmcr = BMCR_ANENABLE;
152 	} else {
153 		bmcr = 0;
154 	}
155 
156 	if (mpcs->interface != interface) {
157 		link_timer = phylink_get_link_timer_ns(interface);
158 		if (link_timer < 0)
159 			return link_timer;
160 
161 		/* PHYA power down */
162 		regmap_set_bits(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL,
163 				SGMII_PHYA_PWD);
164 
165 		/* Reset SGMII PCS state */
166 		regmap_set_bits(mpcs->regmap, SGMSYS_RESERVED_0,
167 				SGMII_SW_RESET);
168 
169 		if (mpcs->flags & MTK_SGMII_FLAG_PN_SWAP)
170 			regmap_update_bits(mpcs->regmap, SGMSYS_QPHY_WRAP_CTRL,
171 					   SGMII_PN_SWAP_MASK,
172 					   SGMII_PN_SWAP_TX_RX);
173 
174 		if (interface == PHY_INTERFACE_MODE_2500BASEX)
175 			rgc3 = SGMII_PHY_SPEED_3_125G;
176 		else
177 			rgc3 = SGMII_PHY_SPEED_1_25G;
178 
179 		/* Configure the underlying interface speed */
180 		regmap_update_bits(mpcs->regmap, mpcs->ana_rgc3,
181 				   SGMII_PHY_SPEED_MASK, rgc3);
182 
183 		/* Setup the link timer */
184 		regmap_write(mpcs->regmap, SGMSYS_PCS_LINK_TIMER,
185 			     SGMII_LINK_TIMER_VAL(link_timer));
186 
187 		mpcs->interface = interface;
188 		mode_changed = true;
189 	}
190 
191 	/* Update the advertisement, noting whether it has changed */
192 	regmap_update_bits_check(mpcs->regmap, SGMSYS_PCS_ADVERTISE,
193 				 SGMII_ADVERTISE, advertise, &changed);
194 
195 	/* Update the sgmsys mode register */
196 	regmap_update_bits(mpcs->regmap, SGMSYS_SGMII_MODE,
197 			   SGMII_REMOTE_FAULT_DIS | SGMII_SPEED_DUPLEX_AN |
198 			   SGMII_IF_MODE_SGMII, sgm_mode);
199 
200 	/* Update the BMCR */
201 	regmap_update_bits(mpcs->regmap, SGMSYS_PCS_CONTROL_1,
202 			   BMCR_ANENABLE, bmcr);
203 
204 	/* Release PHYA power down state
205 	 * Only removing bit SGMII_PHYA_PWD isn't enough.
206 	 * There are cases when the SGMII_PHYA_PWD register contains 0x9 which
207 	 * prevents SGMII from working. The SGMII still shows link but no traffic
208 	 * can flow. Writing 0x0 to the PHYA_PWD register fix the issue. 0x0 was
209 	 * taken from a good working state of the SGMII interface.
210 	 * Unknown how much the QPHY needs but it is racy without a sleep.
211 	 * Tested on mt7622 & mt7986.
212 	 */
213 	usleep_range(50, 100);
214 	regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, 0);
215 
216 	return changed || mode_changed;
217 }
218 
219 static void mtk_pcs_lynxi_restart_an(struct phylink_pcs *pcs)
220 {
221 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
222 
223 	regmap_set_bits(mpcs->regmap, SGMSYS_PCS_CONTROL_1, BMCR_ANRESTART);
224 }
225 
226 static void mtk_pcs_lynxi_link_up(struct phylink_pcs *pcs,
227 				  unsigned int neg_mode,
228 				  phy_interface_t interface, int speed,
229 				  int duplex)
230 {
231 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
232 	unsigned int sgm_mode;
233 
234 	if (neg_mode != PHYLINK_PCS_NEG_INBAND_ENABLED) {
235 		/* Force the speed and duplex setting */
236 		if (speed == SPEED_10)
237 			sgm_mode = SGMII_SPEED_10;
238 		else if (speed == SPEED_100)
239 			sgm_mode = SGMII_SPEED_100;
240 		else
241 			sgm_mode = SGMII_SPEED_1000;
242 
243 		if (duplex != DUPLEX_FULL)
244 			sgm_mode |= SGMII_DUPLEX_HALF;
245 
246 		regmap_update_bits(mpcs->regmap, SGMSYS_SGMII_MODE,
247 				   SGMII_DUPLEX_HALF | SGMII_SPEED_MASK,
248 				   sgm_mode);
249 	}
250 }
251 
252 static void mtk_pcs_lynxi_disable(struct phylink_pcs *pcs)
253 {
254 	struct mtk_pcs_lynxi *mpcs = pcs_to_mtk_pcs_lynxi(pcs);
255 
256 	mpcs->interface = PHY_INTERFACE_MODE_NA;
257 }
258 
259 static const struct phylink_pcs_ops mtk_pcs_lynxi_ops = {
260 	.pcs_inband_caps = mtk_pcs_lynxi_inband_caps,
261 	.pcs_get_state = mtk_pcs_lynxi_get_state,
262 	.pcs_config = mtk_pcs_lynxi_config,
263 	.pcs_an_restart = mtk_pcs_lynxi_restart_an,
264 	.pcs_link_up = mtk_pcs_lynxi_link_up,
265 	.pcs_disable = mtk_pcs_lynxi_disable,
266 };
267 
268 struct phylink_pcs *mtk_pcs_lynxi_create(struct device *dev,
269 					 struct regmap *regmap, u32 ana_rgc3,
270 					 u32 flags)
271 {
272 	struct mtk_pcs_lynxi *mpcs;
273 	u32 id, ver;
274 	int ret;
275 
276 	ret = regmap_read(regmap, SGMSYS_PCS_DEVICE_ID, &id);
277 	if (ret < 0)
278 		return NULL;
279 
280 	if (id != SGMII_LYNXI_DEV_ID) {
281 		dev_err(dev, "unknown PCS device id %08x\n", id);
282 		return NULL;
283 	}
284 
285 	ret = regmap_read(regmap, SGMSYS_PCS_SCRATCH, &ver);
286 	if (ret < 0)
287 		return NULL;
288 
289 	ver = FIELD_GET(SGMII_DEV_VERSION, ver);
290 	if (ver != 0x1) {
291 		dev_err(dev, "unknown PCS device version %04x\n", ver);
292 		return NULL;
293 	}
294 
295 	dev_dbg(dev, "MediaTek LynxI SGMII PCS (id 0x%08x, ver 0x%04x)\n", id,
296 		ver);
297 
298 	mpcs = kzalloc(sizeof(*mpcs), GFP_KERNEL);
299 	if (!mpcs)
300 		return NULL;
301 
302 	mpcs->ana_rgc3 = ana_rgc3;
303 	mpcs->regmap = regmap;
304 	mpcs->flags = flags;
305 	mpcs->pcs.ops = &mtk_pcs_lynxi_ops;
306 	mpcs->pcs.neg_mode = true;
307 	mpcs->pcs.poll = true;
308 	mpcs->interface = PHY_INTERFACE_MODE_NA;
309 
310 	__set_bit(PHY_INTERFACE_MODE_SGMII, mpcs->pcs.supported_interfaces);
311 	__set_bit(PHY_INTERFACE_MODE_1000BASEX, mpcs->pcs.supported_interfaces);
312 	__set_bit(PHY_INTERFACE_MODE_2500BASEX, mpcs->pcs.supported_interfaces);
313 
314 	return &mpcs->pcs;
315 }
316 EXPORT_SYMBOL(mtk_pcs_lynxi_create);
317 
318 void mtk_pcs_lynxi_destroy(struct phylink_pcs *pcs)
319 {
320 	if (!pcs)
321 		return;
322 
323 	kfree(pcs_to_mtk_pcs_lynxi(pcs));
324 }
325 EXPORT_SYMBOL(mtk_pcs_lynxi_destroy);
326 
327 MODULE_DESCRIPTION("MediaTek SGMII library for LynxI");
328 MODULE_LICENSE("GPL");
329