1// SPDX-License-Identifier: GPL-2.0
2// Broadcom BCM84881 NBASE-T PHY driver, as found on a SFP+ module.
3// Copyright (C) 2019 Russell King, Deep Blue Solutions Ltd.
4//
5// Like the Marvell 88x3310, the Broadcom 84881 changes its host-side
6// interface according to the operating speed between 10GBASE-R,
7// 2500BASE-X and SGMII (but unlike the 88x3310, without the control
8// word).
9//
10// This driver only supports those aspects of the PHY that I'm able to
11// observe and test with the SFP+ module, which is an incomplete subset
12// of what this PHY is able to support. For example, I only assume it
13// supports a single lane Serdes connection, but it may be that the PHY
14// is able to support more than that.
15#include <linux/delay.h>
16#include <linux/module.h>
17#include <linux/phy.h>
18
19enum {
20 MDIO_AN_C22 = 0xffe0,
21};
22
23static int bcm84881_wait_init(struct phy_device *phydev)
24{
25 int val;
26
27 return phy_read_mmd_poll_timeout(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1,
28 val, !(val & MDIO_CTRL1_RESET),
29 100000, 2000000, false);
30}
31
32static int bcm84881_config_init(struct phy_device *phydev)
33{
34 switch (phydev->interface) {
35 case PHY_INTERFACE_MODE_SGMII:
36 case PHY_INTERFACE_MODE_2500BASEX:
37 case PHY_INTERFACE_MODE_10GBASER:
38 break;
39 default:
40 return -ENODEV;
41 }
42 return 0;
43}
44
45static int bcm84881_probe(struct phy_device *phydev)
46{
47 /* This driver requires PMAPMD and AN blocks */
48 const u32 mmd_mask = MDIO_DEVS_PMAPMD | MDIO_DEVS_AN;
49
50 if (!phydev->is_c45 ||
51 (phydev->c45_ids.devices_in_package & mmd_mask) != mmd_mask)
52 return -ENODEV;
53
54 return 0;
55}
56
57static int bcm84881_get_features(struct phy_device *phydev)
58{
59 int ret;
60
61 ret = genphy_c45_pma_read_abilities(phydev);
62 if (ret)
63 return ret;
64
65 /* Although the PHY sets bit 1.11.8, it does not support 10M modes */
66 linkmode_clear_bit(nr: ETHTOOL_LINK_MODE_10baseT_Half_BIT,
67 addr: phydev->supported);
68 linkmode_clear_bit(nr: ETHTOOL_LINK_MODE_10baseT_Full_BIT,
69 addr: phydev->supported);
70
71 return 0;
72}
73
74static int bcm84881_config_aneg(struct phy_device *phydev)
75{
76 bool changed = false;
77 u32 adv;
78 int ret;
79
80 /* Wait for the PHY to finish initialising, otherwise our
81 * advertisement may be overwritten.
82 */
83 ret = bcm84881_wait_init(phydev);
84 if (ret)
85 return ret;
86
87 /* We don't support manual MDI control */
88 phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
89
90 /* disabled autoneg doesn't seem to work with this PHY */
91 if (phydev->autoneg == AUTONEG_DISABLE)
92 return -EINVAL;
93
94 ret = genphy_c45_an_config_aneg(phydev);
95 if (ret < 0)
96 return ret;
97 if (ret > 0)
98 changed = true;
99
100 adv = linkmode_adv_to_mii_ctrl1000_t(advertising: phydev->advertising);
101 ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN,
102 regnum: MDIO_AN_C22 + MII_CTRL1000,
103 ADVERTISE_1000FULL | ADVERTISE_1000HALF,
104 set: adv);
105 if (ret < 0)
106 return ret;
107 if (ret > 0)
108 changed = true;
109
110 return genphy_c45_check_and_restart_aneg(phydev, restart: changed);
111}
112
113static int bcm84881_aneg_done(struct phy_device *phydev)
114{
115 int bmsr, val;
116
117 val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
118 if (val < 0)
119 return val;
120
121 bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, regnum: MDIO_AN_C22 + MII_BMSR);
122 if (bmsr < 0)
123 return val;
124
125 return !!(val & MDIO_AN_STAT1_COMPLETE) &&
126 !!(bmsr & BMSR_ANEGCOMPLETE);
127}
128
129static int bcm84881_read_status(struct phy_device *phydev)
130{
131 unsigned int mode;
132 int bmsr, val;
133
134 val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1);
135 if (val < 0)
136 return val;
137
138 if (val & MDIO_AN_CTRL1_RESTART) {
139 phydev->link = 0;
140 return 0;
141 }
142
143 val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
144 if (val < 0)
145 return val;
146
147 bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, regnum: MDIO_AN_C22 + MII_BMSR);
148 if (bmsr < 0)
149 return val;
150
151 phydev->autoneg_complete = !!(val & MDIO_AN_STAT1_COMPLETE) &&
152 !!(bmsr & BMSR_ANEGCOMPLETE);
153 phydev->link = !!(val & MDIO_STAT1_LSTATUS) &&
154 !!(bmsr & BMSR_LSTATUS);
155 if (phydev->autoneg == AUTONEG_ENABLE && !phydev->autoneg_complete)
156 phydev->link = false;
157
158 linkmode_zero(dst: phydev->lp_advertising);
159 phydev->speed = SPEED_UNKNOWN;
160 phydev->duplex = DUPLEX_UNKNOWN;
161 phydev->pause = 0;
162 phydev->asym_pause = 0;
163 phydev->mdix = 0;
164
165 if (!phydev->link)
166 return 0;
167
168 if (phydev->autoneg_complete) {
169 val = genphy_c45_read_lpa(phydev);
170 if (val < 0)
171 return val;
172
173 val = phy_read_mmd(phydev, MDIO_MMD_AN,
174 regnum: MDIO_AN_C22 + MII_STAT1000);
175 if (val < 0)
176 return val;
177
178 mii_stat1000_mod_linkmode_lpa_t(advertising: phydev->lp_advertising, lpa: val);
179
180 if (phydev->autoneg == AUTONEG_ENABLE)
181 phy_resolve_aneg_linkmode(phydev);
182 }
183
184 if (phydev->autoneg == AUTONEG_DISABLE) {
185 /* disabled autoneg doesn't seem to work, so force the link
186 * down.
187 */
188 phydev->link = 0;
189 return 0;
190 }
191
192 /* Set the host link mode - we set the phy interface mode and
193 * the speed according to this register so that downshift works.
194 * We leave the duplex setting as per the resolution from the
195 * above.
196 */
197 val = phy_read_mmd(phydev, MDIO_MMD_VEND1, regnum: 0x4011);
198 mode = (val & 0x1e) >> 1;
199 if (mode == 1 || mode == 2)
200 phydev->interface = PHY_INTERFACE_MODE_SGMII;
201 else if (mode == 3)
202 phydev->interface = PHY_INTERFACE_MODE_10GBASER;
203 else if (mode == 4)
204 phydev->interface = PHY_INTERFACE_MODE_2500BASEX;
205 switch (mode & 7) {
206 case 1:
207 phydev->speed = SPEED_100;
208 break;
209 case 2:
210 phydev->speed = SPEED_1000;
211 break;
212 case 3:
213 phydev->speed = SPEED_10000;
214 break;
215 case 4:
216 phydev->speed = SPEED_2500;
217 break;
218 case 5:
219 phydev->speed = SPEED_5000;
220 break;
221 }
222
223 return genphy_c45_read_mdix(phydev);
224}
225
226static struct phy_driver bcm84881_drivers[] = {
227 {
228 .phy_id = 0xae025150,
229 .phy_id_mask = 0xfffffff0,
230 .name = "Broadcom BCM84881",
231 .config_init = bcm84881_config_init,
232 .probe = bcm84881_probe,
233 .get_features = bcm84881_get_features,
234 .config_aneg = bcm84881_config_aneg,
235 .aneg_done = bcm84881_aneg_done,
236 .read_status = bcm84881_read_status,
237 },
238};
239
240module_phy_driver(bcm84881_drivers);
241
242/* FIXME: module auto-loading for Clause 45 PHYs seems non-functional */
243static struct mdio_device_id __maybe_unused bcm84881_tbl[] = {
244 { 0xae025150, 0xfffffff0 },
245 { },
246};
247MODULE_AUTHOR("Russell King");
248MODULE_DESCRIPTION("Broadcom BCM84881 PHY driver");
249MODULE_DEVICE_TABLE(mdio, bcm84881_tbl);
250MODULE_LICENSE("GPL");
251

source code of linux/drivers/net/phy/bcm84881.c