1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Software PHY emulation 4 * 5 * Code taken from fixed_phy.c by Russell King. 6 * 7 * Author: Vitaly Bordug <vbordug@ru.mvista.com> 8 * Anton Vorontsov <avorontsov@ru.mvista.com> 9 * 10 * Copyright (c) 2006-2007 MontaVista Software, Inc. 11 */ 12 #include <linux/export.h> 13 #include <linux/mii.h> 14 #include <linux/phy.h> 15 #include <linux/phy_fixed.h> 16 17 #include "swphy.h" 18 19 #define MII_REGS_NUM 29 20 21 struct swmii_regs { 22 u16 bmsr; 23 u16 lpa; 24 u16 lpagb; 25 u16 estat; 26 }; 27 28 enum { 29 SWMII_SPEED_10 = 0, 30 SWMII_SPEED_100, 31 SWMII_SPEED_1000, 32 SWMII_DUPLEX_HALF = 0, 33 SWMII_DUPLEX_FULL, 34 }; 35 36 /* 37 * These two tables get bitwise-anded together to produce the final result. 38 * This means the speed table must contain both duplex settings, and the 39 * duplex table must contain all speed settings. 40 */ 41 static const struct swmii_regs speed[] = { 42 [SWMII_SPEED_10] = { 43 .lpa = LPA_10FULL | LPA_10HALF, 44 }, 45 [SWMII_SPEED_100] = { 46 .bmsr = BMSR_100FULL | BMSR_100HALF, 47 .lpa = LPA_100FULL | LPA_100HALF, 48 }, 49 [SWMII_SPEED_1000] = { 50 .bmsr = BMSR_ESTATEN, 51 .lpagb = LPA_1000FULL | LPA_1000HALF, 52 .estat = ESTATUS_1000_TFULL | ESTATUS_1000_THALF, 53 }, 54 }; 55 56 static const struct swmii_regs duplex[] = { 57 [SWMII_DUPLEX_HALF] = { 58 .bmsr = BMSR_ESTATEN | BMSR_100HALF, 59 .lpa = LPA_10HALF | LPA_100HALF, 60 .lpagb = LPA_1000HALF, 61 .estat = ESTATUS_1000_THALF, 62 }, 63 [SWMII_DUPLEX_FULL] = { 64 .bmsr = BMSR_ESTATEN | BMSR_100FULL, 65 .lpa = LPA_10FULL | LPA_100FULL, 66 .lpagb = LPA_1000FULL, 67 .estat = ESTATUS_1000_TFULL, 68 }, 69 }; 70 71 static int swphy_decode_speed(int speed) 72 { 73 switch (speed) { 74 case 1000: 75 return SWMII_SPEED_1000; 76 case 100: 77 return SWMII_SPEED_100; 78 case 10: 79 return SWMII_SPEED_10; 80 default: 81 return -EINVAL; 82 } 83 } 84 85 /** 86 * swphy_validate_state - validate the software phy status 87 * @state: software phy status 88 * 89 * This checks that we can represent the state stored in @state can be 90 * represented in the emulated MII registers. Returns 0 if it can, 91 * otherwise returns -EINVAL. 92 */ 93 int swphy_validate_state(const struct fixed_phy_status *state) 94 { 95 int err; 96 97 if (state->link) { 98 err = swphy_decode_speed(state->speed); 99 if (err < 0) { 100 pr_warn("swphy: unknown speed\n"); 101 return -EINVAL; 102 } 103 } 104 return 0; 105 } 106 EXPORT_SYMBOL_GPL(swphy_validate_state); 107 108 /** 109 * swphy_read_reg - return a MII register from the fixed phy state 110 * @reg: MII register 111 * @state: fixed phy status 112 * 113 * Return the MII @reg register generated from the fixed phy state @state. 114 */ 115 int swphy_read_reg(int reg, const struct fixed_phy_status *state) 116 { 117 int speed_index, duplex_index; 118 u16 bmsr = BMSR_ANEGCAPABLE; 119 u16 estat = 0; 120 u16 lpagb = 0; 121 u16 lpa = 0; 122 123 if (reg > MII_REGS_NUM) 124 return -1; 125 126 speed_index = swphy_decode_speed(state->speed); 127 if (WARN_ON(speed_index < 0)) 128 return 0; 129 130 duplex_index = state->duplex ? SWMII_DUPLEX_FULL : SWMII_DUPLEX_HALF; 131 132 bmsr |= speed[speed_index].bmsr & duplex[duplex_index].bmsr; 133 estat |= speed[speed_index].estat & duplex[duplex_index].estat; 134 135 if (state->link) { 136 bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE; 137 138 lpa |= speed[speed_index].lpa & duplex[duplex_index].lpa; 139 lpagb |= speed[speed_index].lpagb & duplex[duplex_index].lpagb; 140 141 if (state->pause) 142 lpa |= LPA_PAUSE_CAP; 143 144 if (state->asym_pause) 145 lpa |= LPA_PAUSE_ASYM; 146 } 147 148 switch (reg) { 149 case MII_BMCR: 150 return BMCR_ANENABLE; 151 case MII_BMSR: 152 return bmsr; 153 case MII_PHYSID1: 154 case MII_PHYSID2: 155 return 0; 156 case MII_LPA: 157 return lpa; 158 case MII_STAT1000: 159 return lpagb; 160 case MII_ESTATUS: 161 return estat; 162 163 /* 164 * We do not support emulating Clause 45 over Clause 22 register 165 * reads. Return an error instead of bogus data. 166 */ 167 case MII_MMD_CTRL: 168 case MII_MMD_DATA: 169 return -1; 170 171 default: 172 return 0xffff; 173 } 174 } 175 EXPORT_SYMBOL_GPL(swphy_read_reg); 176