xref: /openbmc/linux/drivers/net/dsa/b53/b53_serdes.c (revision 2cf1c348)
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, 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 	bmsr = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMSR),
111 			       SERDES_MII_BLK);
112 
113 	switch ((dig >> SPEED_STATUS_SHIFT) & SPEED_STATUS_MASK) {
114 	case SPEED_STATUS_10:
115 		state->speed = SPEED_10;
116 		break;
117 	case SPEED_STATUS_100:
118 		state->speed = SPEED_100;
119 		break;
120 	case SPEED_STATUS_1000:
121 		state->speed = SPEED_1000;
122 		break;
123 	default:
124 	case SPEED_STATUS_2500:
125 		state->speed = SPEED_2500;
126 		break;
127 	}
128 
129 	state->duplex = dig & DUPLEX_STATUS ? DUPLEX_FULL : DUPLEX_HALF;
130 	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
131 	state->link = !!(dig & LINK_STATUS);
132 	if (dig & PAUSE_RESOLUTION_RX_SIDE)
133 		state->pause |= MLO_PAUSE_RX;
134 	if (dig & PAUSE_RESOLUTION_TX_SIDE)
135 		state->pause |= MLO_PAUSE_TX;
136 
137 	return 0;
138 }
139 EXPORT_SYMBOL(b53_serdes_link_state);
140 
141 void b53_serdes_link_set(struct b53_device *dev, int port, unsigned int mode,
142 			 phy_interface_t interface, bool link_up)
143 {
144 	u8 lane = b53_serdes_map_lane(dev, port);
145 	u16 reg;
146 
147 	if (lane == B53_INVALID_LANE)
148 		return;
149 
150 	reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
151 			      SERDES_MII_BLK);
152 	if (link_up)
153 		reg &= ~BMCR_PDOWN;
154 	else
155 		reg |= BMCR_PDOWN;
156 	b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
157 			 SERDES_MII_BLK, reg);
158 }
159 EXPORT_SYMBOL(b53_serdes_link_set);
160 
161 void b53_serdes_phylink_validate(struct b53_device *dev, int port,
162 				 unsigned long *supported,
163 				 struct phylink_link_state *state)
164 {
165 	u8 lane = b53_serdes_map_lane(dev, port);
166 
167 	if (lane == B53_INVALID_LANE)
168 		return;
169 
170 	switch (lane) {
171 	case 0:
172 		phylink_set(supported, 2500baseX_Full);
173 		fallthrough;
174 	case 1:
175 		phylink_set(supported, 1000baseX_Full);
176 		break;
177 	default:
178 		break;
179 	}
180 }
181 EXPORT_SYMBOL(b53_serdes_phylink_validate);
182 
183 int b53_serdes_init(struct b53_device *dev, int port)
184 {
185 	u8 lane = b53_serdes_map_lane(dev, port);
186 	u16 id0, msb, lsb;
187 
188 	if (lane == B53_INVALID_LANE)
189 		return -EINVAL;
190 
191 	id0 = b53_serdes_read(dev, lane, B53_SERDES_ID0, SERDES_ID0);
192 	msb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID1),
193 			      SERDES_MII_BLK);
194 	lsb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID2),
195 			      SERDES_MII_BLK);
196 	if (id0 == 0 || id0 == 0xffff) {
197 		dev_err(dev->dev, "SerDes not initialized, check settings\n");
198 		return -ENODEV;
199 	}
200 
201 	dev_info(dev->dev,
202 		 "SerDes lane %d, model: %d, rev %c%d (OUI: 0x%08x)\n",
203 		 lane, id0 & SERDES_ID0_MODEL_MASK,
204 		 (id0 >> SERDES_ID0_REV_LETTER_SHIFT) + 0x41,
205 		 (id0 >> SERDES_ID0_REV_NUM_SHIFT) & SERDES_ID0_REV_NUM_MASK,
206 		 (u32)msb << 16 | lsb);
207 
208 	return 0;
209 }
210 EXPORT_SYMBOL(b53_serdes_init);
211 
212 MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
213 MODULE_DESCRIPTION("B53 Switch SerDes driver");
214 MODULE_LICENSE("Dual BSD/GPL");
215