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 | |
19 | enum { |
20 | MDIO_AN_C22 = 0xffe0, |
21 | }; |
22 | |
23 | static 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 | |
32 | static void bcm84881_fill_possible_interfaces(struct phy_device *phydev) |
33 | { |
34 | unsigned long *possible = phydev->possible_interfaces; |
35 | |
36 | __set_bit(PHY_INTERFACE_MODE_SGMII, possible); |
37 | __set_bit(PHY_INTERFACE_MODE_2500BASEX, possible); |
38 | __set_bit(PHY_INTERFACE_MODE_10GBASER, possible); |
39 | } |
40 | |
41 | static int bcm84881_config_init(struct phy_device *phydev) |
42 | { |
43 | bcm84881_fill_possible_interfaces(phydev); |
44 | |
45 | switch (phydev->interface) { |
46 | case PHY_INTERFACE_MODE_SGMII: |
47 | case PHY_INTERFACE_MODE_2500BASEX: |
48 | case PHY_INTERFACE_MODE_10GBASER: |
49 | break; |
50 | default: |
51 | return -ENODEV; |
52 | } |
53 | |
54 | return 0; |
55 | } |
56 | |
57 | static int bcm84881_probe(struct phy_device *phydev) |
58 | { |
59 | /* This driver requires PMAPMD and AN blocks */ |
60 | const u32 mmd_mask = MDIO_DEVS_PMAPMD | MDIO_DEVS_AN; |
61 | |
62 | if (!phydev->is_c45 || |
63 | (phydev->c45_ids.devices_in_package & mmd_mask) != mmd_mask) |
64 | return -ENODEV; |
65 | |
66 | return 0; |
67 | } |
68 | |
69 | static int bcm84881_get_features(struct phy_device *phydev) |
70 | { |
71 | int ret; |
72 | |
73 | ret = genphy_c45_pma_read_abilities(phydev); |
74 | if (ret) |
75 | return ret; |
76 | |
77 | /* Although the PHY sets bit 1.11.8, it does not support 10M modes */ |
78 | linkmode_clear_bit(nr: ETHTOOL_LINK_MODE_10baseT_Half_BIT, |
79 | addr: phydev->supported); |
80 | linkmode_clear_bit(nr: ETHTOOL_LINK_MODE_10baseT_Full_BIT, |
81 | addr: phydev->supported); |
82 | |
83 | return 0; |
84 | } |
85 | |
86 | static int bcm84881_config_aneg(struct phy_device *phydev) |
87 | { |
88 | bool changed = false; |
89 | u32 adv; |
90 | int ret; |
91 | |
92 | /* Wait for the PHY to finish initialising, otherwise our |
93 | * advertisement may be overwritten. |
94 | */ |
95 | ret = bcm84881_wait_init(phydev); |
96 | if (ret) |
97 | return ret; |
98 | |
99 | /* We don't support manual MDI control */ |
100 | phydev->mdix_ctrl = ETH_TP_MDI_AUTO; |
101 | |
102 | /* disabled autoneg doesn't seem to work with this PHY */ |
103 | if (phydev->autoneg == AUTONEG_DISABLE) |
104 | return -EINVAL; |
105 | |
106 | ret = genphy_c45_an_config_aneg(phydev); |
107 | if (ret < 0) |
108 | return ret; |
109 | if (ret > 0) |
110 | changed = true; |
111 | |
112 | adv = linkmode_adv_to_mii_ctrl1000_t(advertising: phydev->advertising); |
113 | ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, |
114 | regnum: MDIO_AN_C22 + MII_CTRL1000, |
115 | ADVERTISE_1000FULL | ADVERTISE_1000HALF, |
116 | set: adv); |
117 | if (ret < 0) |
118 | return ret; |
119 | if (ret > 0) |
120 | changed = true; |
121 | |
122 | return genphy_c45_check_and_restart_aneg(phydev, restart: changed); |
123 | } |
124 | |
125 | static int bcm84881_aneg_done(struct phy_device *phydev) |
126 | { |
127 | int bmsr, val; |
128 | |
129 | val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1); |
130 | if (val < 0) |
131 | return val; |
132 | |
133 | bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, regnum: MDIO_AN_C22 + MII_BMSR); |
134 | if (bmsr < 0) |
135 | return val; |
136 | |
137 | return !!(val & MDIO_AN_STAT1_COMPLETE) && |
138 | !!(bmsr & BMSR_ANEGCOMPLETE); |
139 | } |
140 | |
141 | static int bcm84881_read_status(struct phy_device *phydev) |
142 | { |
143 | unsigned int mode; |
144 | int bmsr, val; |
145 | |
146 | val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1); |
147 | if (val < 0) |
148 | return val; |
149 | |
150 | if (val & MDIO_AN_CTRL1_RESTART) { |
151 | phydev->link = 0; |
152 | return 0; |
153 | } |
154 | |
155 | val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1); |
156 | if (val < 0) |
157 | return val; |
158 | |
159 | bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, regnum: MDIO_AN_C22 + MII_BMSR); |
160 | if (bmsr < 0) |
161 | return val; |
162 | |
163 | phydev->autoneg_complete = !!(val & MDIO_AN_STAT1_COMPLETE) && |
164 | !!(bmsr & BMSR_ANEGCOMPLETE); |
165 | phydev->link = !!(val & MDIO_STAT1_LSTATUS) && |
166 | !!(bmsr & BMSR_LSTATUS); |
167 | if (phydev->autoneg == AUTONEG_ENABLE && !phydev->autoneg_complete) |
168 | phydev->link = false; |
169 | |
170 | linkmode_zero(dst: phydev->lp_advertising); |
171 | phydev->speed = SPEED_UNKNOWN; |
172 | phydev->duplex = DUPLEX_UNKNOWN; |
173 | phydev->pause = 0; |
174 | phydev->asym_pause = 0; |
175 | phydev->mdix = 0; |
176 | |
177 | if (!phydev->link) |
178 | return 0; |
179 | |
180 | if (phydev->autoneg_complete) { |
181 | val = genphy_c45_read_lpa(phydev); |
182 | if (val < 0) |
183 | return val; |
184 | |
185 | val = phy_read_mmd(phydev, MDIO_MMD_AN, |
186 | regnum: MDIO_AN_C22 + MII_STAT1000); |
187 | if (val < 0) |
188 | return val; |
189 | |
190 | mii_stat1000_mod_linkmode_lpa_t(advertising: phydev->lp_advertising, lpa: val); |
191 | |
192 | if (phydev->autoneg == AUTONEG_ENABLE) |
193 | phy_resolve_aneg_linkmode(phydev); |
194 | } |
195 | |
196 | if (phydev->autoneg == AUTONEG_DISABLE) { |
197 | /* disabled autoneg doesn't seem to work, so force the link |
198 | * down. |
199 | */ |
200 | phydev->link = 0; |
201 | return 0; |
202 | } |
203 | |
204 | /* Set the host link mode - we set the phy interface mode and |
205 | * the speed according to this register so that downshift works. |
206 | * We leave the duplex setting as per the resolution from the |
207 | * above. |
208 | */ |
209 | val = phy_read_mmd(phydev, MDIO_MMD_VEND1, regnum: 0x4011); |
210 | mode = (val & 0x1e) >> 1; |
211 | if (mode == 1 || mode == 2) |
212 | phydev->interface = PHY_INTERFACE_MODE_SGMII; |
213 | else if (mode == 3) |
214 | phydev->interface = PHY_INTERFACE_MODE_10GBASER; |
215 | else if (mode == 4) |
216 | phydev->interface = PHY_INTERFACE_MODE_2500BASEX; |
217 | switch (mode & 7) { |
218 | case 1: |
219 | phydev->speed = SPEED_100; |
220 | break; |
221 | case 2: |
222 | phydev->speed = SPEED_1000; |
223 | break; |
224 | case 3: |
225 | phydev->speed = SPEED_10000; |
226 | break; |
227 | case 4: |
228 | phydev->speed = SPEED_2500; |
229 | break; |
230 | case 5: |
231 | phydev->speed = SPEED_5000; |
232 | break; |
233 | } |
234 | |
235 | return genphy_c45_read_mdix(phydev); |
236 | } |
237 | |
238 | static struct phy_driver bcm84881_drivers[] = { |
239 | { |
240 | .phy_id = 0xae025150, |
241 | .phy_id_mask = 0xfffffff0, |
242 | .name = "Broadcom BCM84881" , |
243 | .config_init = bcm84881_config_init, |
244 | .probe = bcm84881_probe, |
245 | .get_features = bcm84881_get_features, |
246 | .config_aneg = bcm84881_config_aneg, |
247 | .aneg_done = bcm84881_aneg_done, |
248 | .read_status = bcm84881_read_status, |
249 | }, |
250 | }; |
251 | |
252 | module_phy_driver(bcm84881_drivers); |
253 | |
254 | /* FIXME: module auto-loading for Clause 45 PHYs seems non-functional */ |
255 | static struct mdio_device_id __maybe_unused bcm84881_tbl[] = { |
256 | { 0xae025150, 0xfffffff0 }, |
257 | { }, |
258 | }; |
259 | MODULE_AUTHOR("Russell King" ); |
260 | MODULE_DESCRIPTION("Broadcom BCM84881 PHY driver" ); |
261 | MODULE_DEVICE_TABLE(mdio, bcm84881_tbl); |
262 | MODULE_LICENSE("GPL" ); |
263 | |