| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Software PHY emulation |
| * |
| * Code taken from fixed_phy.c by Russell King <rmk+kernel@arm.linux.org.uk> |
| * |
| * Author: Vitaly Bordug <vbordug@ru.mvista.com> |
| * Anton Vorontsov <avorontsov@ru.mvista.com> |
| * |
| * Copyright (c) 2006-2007 MontaVista Software, Inc. |
| */ |
| #include <linux/export.h> |
| #include <linux/mii.h> |
| #include <linux/phy.h> |
| #include <linux/phy_fixed.h> |
| |
| #include "swphy.h" |
| |
| #define MII_REGS_NUM 29 |
| |
| struct swmii_regs { |
| u16 bmsr; |
| u16 lpa; |
| u16 lpagb; |
| u16 estat; |
| }; |
| |
| enum { |
| SWMII_SPEED_10 = 0, |
| SWMII_SPEED_100, |
| SWMII_SPEED_1000, |
| SWMII_DUPLEX_HALF = 0, |
| SWMII_DUPLEX_FULL, |
| }; |
| |
| /* |
| * These two tables get bitwise-anded together to produce the final result. |
| * This means the speed table must contain both duplex settings, and the |
| * duplex table must contain all speed settings. |
| */ |
| static const struct swmii_regs speed[] = { |
| [SWMII_SPEED_10] = { |
| .lpa = LPA_10FULL | LPA_10HALF, |
| }, |
| [SWMII_SPEED_100] = { |
| .bmsr = BMSR_100FULL | BMSR_100HALF, |
| .lpa = LPA_100FULL | LPA_100HALF, |
| }, |
| [SWMII_SPEED_1000] = { |
| .bmsr = BMSR_ESTATEN, |
| .lpagb = LPA_1000FULL | LPA_1000HALF, |
| .estat = ESTATUS_1000_TFULL | ESTATUS_1000_THALF, |
| }, |
| }; |
| |
| static const struct swmii_regs duplex[] = { |
| [SWMII_DUPLEX_HALF] = { |
| .bmsr = BMSR_ESTATEN | BMSR_100HALF, |
| .lpa = LPA_10HALF | LPA_100HALF, |
| .lpagb = LPA_1000HALF, |
| .estat = ESTATUS_1000_THALF, |
| }, |
| [SWMII_DUPLEX_FULL] = { |
| .bmsr = BMSR_ESTATEN | BMSR_100FULL, |
| .lpa = LPA_10FULL | LPA_100FULL, |
| .lpagb = LPA_1000FULL, |
| .estat = ESTATUS_1000_TFULL, |
| }, |
| }; |
| |
| static int swphy_decode_speed(int speed) |
| { |
| switch (speed) { |
| case 1000: |
| return SWMII_SPEED_1000; |
| case 100: |
| return SWMII_SPEED_100; |
| case 10: |
| return SWMII_SPEED_10; |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| /** |
| * swphy_validate_state - validate the software phy status |
| * @state: software phy status |
| * |
| * This checks that we can represent the state stored in @state can be |
| * represented in the emulated MII registers. Returns 0 if it can, |
| * otherwise returns -EINVAL. |
| */ |
| int swphy_validate_state(const struct fixed_phy_status *state) |
| { |
| int err; |
| |
| if (state->link) { |
| err = swphy_decode_speed(state->speed); |
| if (err < 0) { |
| pr_warn("swphy: unknown speed\n"); |
| return -EINVAL; |
| } |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(swphy_validate_state); |
| |
| /** |
| * swphy_read_reg - return a MII register from the fixed phy state |
| * @reg: MII register |
| * @state: fixed phy status |
| * |
| * Return the MII @reg register generated from the fixed phy state @state. |
| */ |
| int swphy_read_reg(int reg, const struct fixed_phy_status *state) |
| { |
| int speed_index, duplex_index; |
| u16 bmsr = BMSR_ANEGCAPABLE; |
| u16 estat = 0; |
| u16 lpagb = 0; |
| u16 lpa = 0; |
| |
| if (reg > MII_REGS_NUM) |
| return -1; |
| |
| speed_index = swphy_decode_speed(state->speed); |
| if (WARN_ON(speed_index < 0)) |
| return 0; |
| |
| duplex_index = state->duplex ? SWMII_DUPLEX_FULL : SWMII_DUPLEX_HALF; |
| |
| bmsr |= speed[speed_index].bmsr & duplex[duplex_index].bmsr; |
| estat |= speed[speed_index].estat & duplex[duplex_index].estat; |
| |
| if (state->link) { |
| bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE; |
| |
| lpa |= speed[speed_index].lpa & duplex[duplex_index].lpa; |
| lpagb |= speed[speed_index].lpagb & duplex[duplex_index].lpagb; |
| |
| if (state->pause) |
| lpa |= LPA_PAUSE_CAP; |
| |
| if (state->asym_pause) |
| lpa |= LPA_PAUSE_ASYM; |
| } |
| |
| switch (reg) { |
| case MII_BMCR: |
| return BMCR_ANENABLE; |
| case MII_BMSR: |
| return bmsr; |
| case MII_PHYSID1: |
| case MII_PHYSID2: |
| return 0; |
| case MII_LPA: |
| return lpa; |
| case MII_STAT1000: |
| return lpagb; |
| case MII_ESTATUS: |
| return estat; |
| |
| /* |
| * We do not support emulating Clause 45 over Clause 22 register |
| * reads. Return an error instead of bogus data. |
| */ |
| case MII_MMD_CTRL: |
| case MII_MMD_DATA: |
| return -1; |
| |
| default: |
| return 0xffff; |
| } |
| } |
| EXPORT_SYMBOL_GPL(swphy_read_reg); |