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| 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 | + unsigned int tries = 20; |
| 26 | + int ret, val; |
| 27 | + |
| 28 | + do { |
| 29 | + val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1); |
| 30 | + if (val < 0) { |
| 31 | + ret = val; |
| 32 | + break; |
| 33 | + } |
| 34 | + if (!(val & MDIO_CTRL1_RESET)) { |
| 35 | + ret = 0; |
| 36 | + break; |
| 37 | + } |
| 38 | + if (!--tries) { |
| 39 | + ret = -ETIMEDOUT; |
| 40 | + break; |
| 41 | + } |
| 42 | + msleep(100); |
| 43 | + } while (1); |
| 44 | + |
| 45 | + if (ret) |
| 46 | + phydev_err(phydev, "%s failed: %d\n", __func__, ret); |
| 47 | + |
| 48 | + return ret; |
| 49 | +} |
| 50 | + |
| 51 | +static int bcm84881_config_init(struct phy_device *phydev) |
| 52 | +{ |
| 53 | + switch (phydev->interface) { |
| 54 | + case PHY_INTERFACE_MODE_SGMII: |
| 55 | + case PHY_INTERFACE_MODE_2500BASEX: |
| 56 | + case PHY_INTERFACE_MODE_10GKR: |
| 57 | + break; |
| 58 | + default: |
| 59 | + return -ENODEV; |
| 60 | + } |
| 61 | + return 0; |
| 62 | +} |
| 63 | + |
| 64 | +static int bcm84881_probe(struct phy_device *phydev) |
| 65 | +{ |
| 66 | + /* This driver requires PMAPMD and AN blocks */ |
| 67 | + const u32 mmd_mask = MDIO_DEVS_PMAPMD | MDIO_DEVS_AN; |
| 68 | + |
| 69 | + if (!phydev->is_c45 || |
| 70 | + (phydev->c45_ids.devices_in_package & mmd_mask) != mmd_mask) |
| 71 | + return -ENODEV; |
| 72 | + |
| 73 | + return 0; |
| 74 | +} |
| 75 | + |
| 76 | +static int bcm84881_get_features(struct phy_device *phydev) |
| 77 | +{ |
| 78 | + int ret; |
| 79 | + |
| 80 | + ret = genphy_c45_pma_read_abilities(phydev); |
| 81 | + if (ret) |
| 82 | + return ret; |
| 83 | + |
| 84 | + /* Although the PHY sets bit 1.11.8, it does not support 10M modes */ |
| 85 | + linkmode_clear_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, |
| 86 | + phydev->supported); |
| 87 | + linkmode_clear_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, |
| 88 | + phydev->supported); |
| 89 | + |
| 90 | + return 0; |
| 91 | +} |
| 92 | + |
| 93 | +static int bcm84881_config_aneg(struct phy_device *phydev) |
| 94 | +{ |
| 95 | + bool changed = false; |
| 96 | + u32 adv; |
| 97 | + int ret; |
| 98 | + |
| 99 | + /* Wait for the PHY to finish initialising, otherwise our |
| 100 | + * advertisement may be overwritten. |
| 101 | + */ |
| 102 | + ret = bcm84881_wait_init(phydev); |
| 103 | + if (ret) |
| 104 | + return ret; |
| 105 | + |
| 106 | + /* We don't support manual MDI control */ |
| 107 | + phydev->mdix_ctrl = ETH_TP_MDI_AUTO; |
| 108 | + |
| 109 | + /* disabled autoneg doesn't seem to work with this PHY */ |
| 110 | + if (phydev->autoneg == AUTONEG_DISABLE) |
| 111 | + return -EINVAL; |
| 112 | + |
| 113 | + ret = genphy_c45_an_config_aneg(phydev); |
| 114 | + if (ret < 0) |
| 115 | + return ret; |
| 116 | + if (ret > 0) |
| 117 | + changed = true; |
| 118 | + |
| 119 | + adv = linkmode_adv_to_mii_ctrl1000_t(phydev->advertising); |
| 120 | + ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, |
| 121 | + MDIO_AN_C22 + MII_CTRL1000, |
| 122 | + ADVERTISE_1000FULL | ADVERTISE_1000HALF, |
| 123 | + adv); |
| 124 | + if (ret < 0) |
| 125 | + return ret; |
| 126 | + if (ret > 0) |
| 127 | + changed = true; |
| 128 | + |
| 129 | + return genphy_c45_check_and_restart_aneg(phydev, changed); |
| 130 | +} |
| 131 | + |
| 132 | +static int bcm84881_aneg_done(struct phy_device *phydev) |
| 133 | +{ |
| 134 | + int bmsr, val; |
| 135 | + |
| 136 | + val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1); |
| 137 | + if (val < 0) |
| 138 | + return val; |
| 139 | + |
| 140 | + bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_C22 + MII_BMSR); |
| 141 | + if (bmsr < 0) |
| 142 | + return val; |
| 143 | + |
| 144 | + return !!(val & MDIO_AN_STAT1_COMPLETE) && |
| 145 | + !!(bmsr & BMSR_ANEGCOMPLETE); |
| 146 | +} |
| 147 | + |
| 148 | +static int bcm84881_read_status(struct phy_device *phydev) |
| 149 | +{ |
| 150 | + unsigned int mode; |
| 151 | + int bmsr, val; |
| 152 | + |
| 153 | + val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1); |
| 154 | + if (val < 0) |
| 155 | + return val; |
| 156 | + |
| 157 | + if (val & MDIO_AN_CTRL1_RESTART) { |
| 158 | + phydev->link = 0; |
| 159 | + return 0; |
| 160 | + } |
| 161 | + |
| 162 | + val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1); |
| 163 | + if (val < 0) |
| 164 | + return val; |
| 165 | + |
| 166 | + bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_C22 + MII_BMSR); |
| 167 | + if (bmsr < 0) |
| 168 | + return val; |
| 169 | + |
| 170 | + phydev->autoneg_complete = !!(val & MDIO_AN_STAT1_COMPLETE) && |
| 171 | + !!(bmsr & BMSR_ANEGCOMPLETE); |
| 172 | + phydev->link = !!(val & MDIO_STAT1_LSTATUS) && |
| 173 | + !!(bmsr & BMSR_LSTATUS); |
| 174 | + if (phydev->autoneg == AUTONEG_ENABLE && !phydev->autoneg_complete) |
| 175 | + phydev->link = false; |
| 176 | + |
| 177 | + if (!phydev->link) |
| 178 | + return 0; |
| 179 | + |
| 180 | + linkmode_zero(phydev->lp_advertising); |
| 181 | + phydev->speed = SPEED_UNKNOWN; |
| 182 | + phydev->duplex = DUPLEX_UNKNOWN; |
| 183 | + phydev->pause = 0; |
| 184 | + phydev->asym_pause = 0; |
| 185 | + phydev->mdix = 0; |
| 186 | + |
| 187 | + if (phydev->autoneg_complete) { |
| 188 | + val = genphy_c45_read_lpa(phydev); |
| 189 | + if (val < 0) |
| 190 | + return val; |
| 191 | + |
| 192 | + val = phy_read_mmd(phydev, MDIO_MMD_AN, |
| 193 | + MDIO_AN_C22 + MII_STAT1000); |
| 194 | + if (val < 0) |
| 195 | + return val; |
| 196 | + |
| 197 | + mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising, val); |
| 198 | + |
| 199 | + if (phydev->autoneg == AUTONEG_ENABLE) |
| 200 | + phy_resolve_aneg_linkmode(phydev); |
| 201 | + } |
| 202 | + |
| 203 | + if (phydev->autoneg == AUTONEG_DISABLE) { |
| 204 | + /* disabled autoneg doesn't seem to work, so force the link |
| 205 | + * down. |
| 206 | + */ |
| 207 | + phydev->link = 0; |
| 208 | + return 0; |
| 209 | + } |
| 210 | + |
| 211 | + /* Set the host link mode - we set the phy interface mode and |
| 212 | + * the speed according to this register so that downshift works. |
| 213 | + * We leave the duplex setting as per the resolution from the |
| 214 | + * above. |
| 215 | + */ |
| 216 | + val = phy_read_mmd(phydev, MDIO_MMD_VEND1, 0x4011); |
| 217 | + mode = (val & 0x1e) >> 1; |
| 218 | + if (mode == 1 || mode == 2) |
| 219 | + phydev->interface = PHY_INTERFACE_MODE_SGMII; |
| 220 | + else if (mode == 3) |
| 221 | + phydev->interface = PHY_INTERFACE_MODE_10GKR; |
| 222 | + else if (mode == 4) |
| 223 | + phydev->interface = PHY_INTERFACE_MODE_2500BASEX; |
| 224 | + switch (mode & 7) { |
| 225 | + case 1: |
| 226 | + phydev->speed = SPEED_100; |
| 227 | + break; |
| 228 | + case 2: |
| 229 | + phydev->speed = SPEED_1000; |
| 230 | + break; |
| 231 | + case 3: |
| 232 | + phydev->speed = SPEED_10000; |
| 233 | + break; |
| 234 | + case 4: |
| 235 | + phydev->speed = SPEED_2500; |
| 236 | + break; |
| 237 | + case 5: |
| 238 | + phydev->speed = SPEED_5000; |
| 239 | + break; |
| 240 | + } |
| 241 | + |
| 242 | + return genphy_c45_read_mdix(phydev); |
| 243 | +} |
| 244 | + |
| 245 | +static struct phy_driver bcm84881_drivers[] = { |
| 246 | + { |
| 247 | + .phy_id = 0xae025150, |
| 248 | + .phy_id_mask = 0xfffffff0, |
| 249 | + .name = "Broadcom BCM84881", |
| 250 | + .config_init = bcm84881_config_init, |
| 251 | + .probe = bcm84881_probe, |
| 252 | + .get_features = bcm84881_get_features, |
| 253 | + .config_aneg = bcm84881_config_aneg, |
| 254 | + .aneg_done = bcm84881_aneg_done, |
| 255 | + .read_status = bcm84881_read_status, |
| 256 | + }, |
| 257 | +}; |
| 258 | + |
| 259 | +module_phy_driver(bcm84881_drivers); |
| 260 | + |
| 261 | +/* FIXME: module auto-loading for Clause 45 PHYs seems non-functional */ |
| 262 | +static struct mdio_device_id __maybe_unused bcm84881_tbl[] = { |
| 263 | + { 0xae025150, 0xfffffff0 }, |
| 264 | + { }, |
| 265 | +}; |
| 266 | +MODULE_AUTHOR("Russell King"); |
| 267 | +MODULE_DESCRIPTION("Broadcom BCM84881 PHY driver"); |
| 268 | +MODULE_DEVICE_TABLE(mdio, bcm84881_tbl); |
| 269 | +MODULE_LICENSE("GPL"); |
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