xref: /openbmc/linux/drivers/net/dsa/b53/b53_serdes.c (revision 88a6f899)
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 inline struct b53_pcs *pcs_to_b53_pcs(struct phylink_pcs *pcs)
21 {
22 	return container_of(pcs, struct b53_pcs, pcs);
23 }
24 
25 static void b53_serdes_write_blk(struct b53_device *dev, u8 offset, u16 block,
26 				 u16 value)
27 {
28 	b53_write16(dev, B53_SERDES_PAGE, B53_SERDES_BLKADDR, block);
29 	b53_write16(dev, B53_SERDES_PAGE, offset, value);
30 }
31 
32 static u16 b53_serdes_read_blk(struct b53_device *dev, u8 offset, u16 block)
33 {
34 	u16 value;
35 
36 	b53_write16(dev, B53_SERDES_PAGE, B53_SERDES_BLKADDR, block);
37 	b53_read16(dev, B53_SERDES_PAGE, offset, &value);
38 
39 	return value;
40 }
41 
42 static void b53_serdes_set_lane(struct b53_device *dev, u8 lane)
43 {
44 	if (dev->serdes_lane == lane)
45 		return;
46 
47 	WARN_ON(lane > 1);
48 
49 	b53_serdes_write_blk(dev, B53_SERDES_LANE,
50 			     SERDES_XGXSBLK0_BLOCKADDRESS, lane);
51 	dev->serdes_lane = lane;
52 }
53 
54 static void b53_serdes_write(struct b53_device *dev, u8 lane,
55 			     u8 offset, u16 block, u16 value)
56 {
57 	b53_serdes_set_lane(dev, lane);
58 	b53_serdes_write_blk(dev, offset, block, value);
59 }
60 
61 static u16 b53_serdes_read(struct b53_device *dev, u8 lane,
62 			   u8 offset, u16 block)
63 {
64 	b53_serdes_set_lane(dev, lane);
65 	return b53_serdes_read_blk(dev, offset, block);
66 }
67 
68 static int b53_serdes_config(struct phylink_pcs *pcs, unsigned int neg_mode,
69 			     phy_interface_t interface,
70 			     const unsigned long *advertising,
71 			     bool permit_pause_to_mac)
72 {
73 	struct b53_device *dev = pcs_to_b53_pcs(pcs)->dev;
74 	u8 lane = pcs_to_b53_pcs(pcs)->lane;
75 	u16 reg;
76 
77 	reg = b53_serdes_read(dev, lane, B53_SERDES_DIGITAL_CONTROL(1),
78 			      SERDES_DIGITAL_BLK);
79 	if (interface == PHY_INTERFACE_MODE_1000BASEX)
80 		reg |= FIBER_MODE_1000X;
81 	else
82 		reg &= ~FIBER_MODE_1000X;
83 	b53_serdes_write(dev, lane, B53_SERDES_DIGITAL_CONTROL(1),
84 			 SERDES_DIGITAL_BLK, reg);
85 
86 	return 0;
87 }
88 
89 static void b53_serdes_an_restart(struct phylink_pcs *pcs)
90 {
91 	struct b53_device *dev = pcs_to_b53_pcs(pcs)->dev;
92 	u8 lane = pcs_to_b53_pcs(pcs)->lane;
93 	u16 reg;
94 
95 	reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
96 			      SERDES_MII_BLK);
97 	reg |= BMCR_ANRESTART;
98 	b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
99 			 SERDES_MII_BLK, reg);
100 }
101 
102 static void b53_serdes_get_state(struct phylink_pcs *pcs,
103 				  struct phylink_link_state *state)
104 {
105 	struct b53_device *dev = pcs_to_b53_pcs(pcs)->dev;
106 	u8 lane = pcs_to_b53_pcs(pcs)->lane;
107 	u16 dig, bmsr;
108 
109 	dig = b53_serdes_read(dev, lane, B53_SERDES_DIGITAL_STATUS,
110 			      SERDES_DIGITAL_BLK);
111 	bmsr = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMSR),
112 			       SERDES_MII_BLK);
113 
114 	switch ((dig >> SPEED_STATUS_SHIFT) & SPEED_STATUS_MASK) {
115 	case SPEED_STATUS_10:
116 		state->speed = SPEED_10;
117 		break;
118 	case SPEED_STATUS_100:
119 		state->speed = SPEED_100;
120 		break;
121 	case SPEED_STATUS_1000:
122 		state->speed = SPEED_1000;
123 		break;
124 	default:
125 	case SPEED_STATUS_2500:
126 		state->speed = SPEED_2500;
127 		break;
128 	}
129 
130 	state->duplex = dig & DUPLEX_STATUS ? DUPLEX_FULL : DUPLEX_HALF;
131 	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
132 	state->link = !!(dig & LINK_STATUS);
133 	if (dig & PAUSE_RESOLUTION_RX_SIDE)
134 		state->pause |= MLO_PAUSE_RX;
135 	if (dig & PAUSE_RESOLUTION_TX_SIDE)
136 		state->pause |= MLO_PAUSE_TX;
137 }
138 
139 void b53_serdes_link_set(struct b53_device *dev, int port, unsigned int mode,
140 			 phy_interface_t interface, bool link_up)
141 {
142 	u8 lane = b53_serdes_map_lane(dev, port);
143 	u16 reg;
144 
145 	if (lane == B53_INVALID_LANE)
146 		return;
147 
148 	reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
149 			      SERDES_MII_BLK);
150 	if (link_up)
151 		reg &= ~BMCR_PDOWN;
152 	else
153 		reg |= BMCR_PDOWN;
154 	b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
155 			 SERDES_MII_BLK, reg);
156 }
157 EXPORT_SYMBOL(b53_serdes_link_set);
158 
159 static const struct phylink_pcs_ops b53_pcs_ops = {
160 	.pcs_get_state = b53_serdes_get_state,
161 	.pcs_config = b53_serdes_config,
162 	.pcs_an_restart = b53_serdes_an_restart,
163 };
164 
165 void b53_serdes_phylink_get_caps(struct b53_device *dev, int port,
166 				 struct phylink_config *config)
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 		/* It appears lane 0 supports 2500base-X and 1000base-X */
176 		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
177 			  config->supported_interfaces);
178 		config->mac_capabilities |= MAC_2500FD;
179 		fallthrough;
180 	case 1:
181 		/* It appears lane 1 only supports 1000base-X and SGMII */
182 		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
183 			  config->supported_interfaces);
184 		__set_bit(PHY_INTERFACE_MODE_SGMII,
185 			  config->supported_interfaces);
186 		config->mac_capabilities |= MAC_1000FD;
187 		break;
188 	default:
189 		break;
190 	}
191 }
192 EXPORT_SYMBOL(b53_serdes_phylink_get_caps);
193 
194 struct phylink_pcs *b53_serdes_phylink_mac_select_pcs(struct b53_device *dev,
195 						      int port,
196 						      phy_interface_t interface)
197 {
198 	u8 lane = b53_serdes_map_lane(dev, port);
199 
200 	if (lane == B53_INVALID_LANE || lane >= B53_N_PCS ||
201 	    !dev->pcs[lane].dev)
202 		return NULL;
203 
204 	if (!phy_interface_mode_is_8023z(interface) &&
205 	    interface != PHY_INTERFACE_MODE_SGMII)
206 		return NULL;
207 
208 	return &dev->pcs[lane].pcs;
209 }
210 EXPORT_SYMBOL(b53_serdes_phylink_mac_select_pcs);
211 
212 int b53_serdes_init(struct b53_device *dev, int port)
213 {
214 	u8 lane = b53_serdes_map_lane(dev, port);
215 	struct b53_pcs *pcs;
216 	u16 id0, msb, lsb;
217 
218 	if (lane == B53_INVALID_LANE)
219 		return -EINVAL;
220 
221 	id0 = b53_serdes_read(dev, lane, B53_SERDES_ID0, SERDES_ID0);
222 	msb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID1),
223 			      SERDES_MII_BLK);
224 	lsb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID2),
225 			      SERDES_MII_BLK);
226 	if (id0 == 0 || id0 == 0xffff) {
227 		dev_err(dev->dev, "SerDes not initialized, check settings\n");
228 		return -ENODEV;
229 	}
230 
231 	dev_info(dev->dev,
232 		 "SerDes lane %d, model: %d, rev %c%d (OUI: 0x%08x)\n",
233 		 lane, id0 & SERDES_ID0_MODEL_MASK,
234 		 (id0 >> SERDES_ID0_REV_LETTER_SHIFT) + 0x41,
235 		 (id0 >> SERDES_ID0_REV_NUM_SHIFT) & SERDES_ID0_REV_NUM_MASK,
236 		 (u32)msb << 16 | lsb);
237 
238 	pcs = &dev->pcs[lane];
239 	pcs->dev = dev;
240 	pcs->lane = lane;
241 	pcs->pcs.ops = &b53_pcs_ops;
242 	pcs->pcs.neg_mode = true;
243 
244 	return 0;
245 }
246 EXPORT_SYMBOL(b53_serdes_init);
247 
248 MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
249 MODULE_DESCRIPTION("B53 Switch SerDes driver");
250 MODULE_LICENSE("Dual BSD/GPL");
251