xref: /openbmc/linux/drivers/net/dsa/b53/b53_serdes.c (revision dd2934a95701576203b2f61e8ded4e4a2f9183ea)
1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
2 /*
3  * Northstar Plus switch SerDes/SGMII PHY main logic
4  *
5  * Copyright (C) 2018 Florian Fainelli <f.fainelli@gmail.com>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/delay.h>
11 #include <linux/kernel.h>
12 #include <linux/phy.h>
13 #include <linux/phylink.h>
14 #include <net/dsa.h>
15 
16 #include "b53_priv.h"
17 #include "b53_serdes.h"
18 #include "b53_regs.h"
19 
20 static void b53_serdes_write_blk(struct b53_device *dev, u8 offset, u16 block,
21 				 u16 value)
22 {
23 	b53_write16(dev, B53_SERDES_PAGE, B53_SERDES_BLKADDR, block);
24 	b53_write16(dev, B53_SERDES_PAGE, offset, value);
25 }
26 
27 static u16 b53_serdes_read_blk(struct b53_device *dev, u8 offset, u16 block)
28 {
29 	u16 value;
30 
31 	b53_write16(dev, B53_SERDES_PAGE, B53_SERDES_BLKADDR, block);
32 	b53_read16(dev, B53_SERDES_PAGE, offset, &value);
33 
34 	return value;
35 }
36 
37 static void b53_serdes_set_lane(struct b53_device *dev, u8 lane)
38 {
39 	if (dev->serdes_lane == lane)
40 		return;
41 
42 	WARN_ON(lane > 1);
43 
44 	b53_serdes_write_blk(dev, B53_SERDES_LANE,
45 			     SERDES_XGXSBLK0_BLOCKADDRESS, lane);
46 	dev->serdes_lane = lane;
47 }
48 
49 static void b53_serdes_write(struct b53_device *dev, u8 lane,
50 			     u8 offset, u16 block, u16 value)
51 {
52 	b53_serdes_set_lane(dev, lane);
53 	b53_serdes_write_blk(dev, offset, block, value);
54 }
55 
56 static u16 b53_serdes_read(struct b53_device *dev, u8 lane,
57 			   u8 offset, u16 block)
58 {
59 	b53_serdes_set_lane(dev, lane);
60 	return b53_serdes_read_blk(dev, offset, block);
61 }
62 
63 void b53_serdes_config(struct b53_device *dev, int port, unsigned int mode,
64 		       const struct phylink_link_state *state)
65 {
66 	u8 lane = b53_serdes_map_lane(dev, port);
67 	u16 reg;
68 
69 	if (lane == B53_INVALID_LANE)
70 		return;
71 
72 	reg = b53_serdes_read(dev, lane, B53_SERDES_DIGITAL_CONTROL(1),
73 			      SERDES_DIGITAL_BLK);
74 	if (state->interface == PHY_INTERFACE_MODE_1000BASEX)
75 		reg |= FIBER_MODE_1000X;
76 	else
77 		reg &= ~FIBER_MODE_1000X;
78 	b53_serdes_write(dev, lane, B53_SERDES_DIGITAL_CONTROL(1),
79 			 SERDES_DIGITAL_BLK, reg);
80 }
81 EXPORT_SYMBOL(b53_serdes_config);
82 
83 void b53_serdes_an_restart(struct b53_device *dev, int port)
84 {
85 	u8 lane = b53_serdes_map_lane(dev, port);
86 	u16 reg;
87 
88 	if (lane == B53_INVALID_LANE)
89 		return;
90 
91 	reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
92 			      SERDES_MII_BLK);
93 	reg |= BMCR_ANRESTART;
94 	b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
95 			 SERDES_MII_BLK, reg);
96 }
97 EXPORT_SYMBOL(b53_serdes_an_restart);
98 
99 int b53_serdes_link_state(struct b53_device *dev, int port,
100 			  struct phylink_link_state *state)
101 {
102 	u8 lane = b53_serdes_map_lane(dev, port);
103 	u16 dig, bmcr, bmsr;
104 
105 	if (lane == B53_INVALID_LANE)
106 		return 1;
107 
108 	dig = b53_serdes_read(dev, lane, B53_SERDES_DIGITAL_STATUS,
109 			      SERDES_DIGITAL_BLK);
110 	bmcr = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
111 			       SERDES_MII_BLK);
112 	bmsr = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMSR),
113 			       SERDES_MII_BLK);
114 
115 	switch ((dig >> SPEED_STATUS_SHIFT) & SPEED_STATUS_MASK) {
116 	case SPEED_STATUS_10:
117 		state->speed = SPEED_10;
118 		break;
119 	case SPEED_STATUS_100:
120 		state->speed = SPEED_100;
121 		break;
122 	case SPEED_STATUS_1000:
123 		state->speed = SPEED_1000;
124 		break;
125 	default:
126 	case SPEED_STATUS_2500:
127 		state->speed = SPEED_2500;
128 		break;
129 	}
130 
131 	state->duplex = dig & DUPLEX_STATUS ? DUPLEX_FULL : DUPLEX_HALF;
132 	state->an_enabled = !!(bmcr & BMCR_ANENABLE);
133 	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
134 	state->link = !!(dig & LINK_STATUS);
135 	if (dig & PAUSE_RESOLUTION_RX_SIDE)
136 		state->pause |= MLO_PAUSE_RX;
137 	if (dig & PAUSE_RESOLUTION_TX_SIDE)
138 		state->pause |= MLO_PAUSE_TX;
139 
140 	return 0;
141 }
142 EXPORT_SYMBOL(b53_serdes_link_state);
143 
144 void b53_serdes_link_set(struct b53_device *dev, int port, unsigned int mode,
145 			 phy_interface_t interface, bool link_up)
146 {
147 	u8 lane = b53_serdes_map_lane(dev, port);
148 	u16 reg;
149 
150 	if (lane == B53_INVALID_LANE)
151 		return;
152 
153 	reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
154 			      SERDES_MII_BLK);
155 	if (link_up)
156 		reg &= ~BMCR_PDOWN;
157 	else
158 		reg |= BMCR_PDOWN;
159 	b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
160 			 SERDES_MII_BLK, reg);
161 }
162 EXPORT_SYMBOL(b53_serdes_link_set);
163 
164 void b53_serdes_phylink_validate(struct b53_device *dev, int port,
165 				 unsigned long *supported,
166 				 struct phylink_link_state *state)
167 {
168 	u8 lane = b53_serdes_map_lane(dev, port);
169 
170 	if (lane == B53_INVALID_LANE)
171 		return;
172 
173 	switch (lane) {
174 	case 0:
175 		phylink_set(supported, 2500baseX_Full);
176 		/* fallthrough */
177 	case 1:
178 		phylink_set(supported, 1000baseX_Full);
179 		break;
180 	default:
181 		break;
182 	}
183 }
184 EXPORT_SYMBOL(b53_serdes_phylink_validate);
185 
186 int b53_serdes_init(struct b53_device *dev, int port)
187 {
188 	u8 lane = b53_serdes_map_lane(dev, port);
189 	u16 id0, msb, lsb;
190 
191 	if (lane == B53_INVALID_LANE)
192 		return -EINVAL;
193 
194 	id0 = b53_serdes_read(dev, lane, B53_SERDES_ID0, SERDES_ID0);
195 	msb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID1),
196 			      SERDES_MII_BLK);
197 	lsb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID2),
198 			      SERDES_MII_BLK);
199 	if (id0 == 0 || id0 == 0xffff) {
200 		dev_err(dev->dev, "SerDes not initialized, check settings\n");
201 		return -ENODEV;
202 	}
203 
204 	dev_info(dev->dev,
205 		 "SerDes lane %d, model: %d, rev %c%d (OUI: 0x%08x)\n",
206 		 lane, id0 & SERDES_ID0_MODEL_MASK,
207 		 (id0 >> SERDES_ID0_REV_LETTER_SHIFT) + 0x41,
208 		 (id0 >> SERDES_ID0_REV_NUM_SHIFT) & SERDES_ID0_REV_NUM_MASK,
209 		 (u32)msb << 16 | lsb);
210 
211 	return 0;
212 }
213 EXPORT_SYMBOL(b53_serdes_init);
214 
215 MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
216 MODULE_DESCRIPTION("B53 Switch SerDes driver");
217 MODULE_LICENSE("Dual BSD/GPL");
218