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(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(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 | |