xref: /openbmc/qemu/include/hw/nvram/xlnx-efuse.h (revision ffe98631)
1 /*
2  * QEMU model of the Xilinx eFuse core
3  *
4  * Copyright (c) 2015 Xilinx Inc.
5  *
6  * Written by Edgar E. Iglesias <edgari@xilinx.com>
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #ifndef XLNX_EFUSE_H
28 #define XLNX_EFUSE_H
29 
30 #include "sysemu/block-backend.h"
31 #include "hw/qdev-core.h"
32 
33 #define TYPE_XLNX_EFUSE "xlnx,efuse"
34 OBJECT_DECLARE_SIMPLE_TYPE(XlnxEFuse, XLNX_EFUSE);
35 
36 struct XlnxEFuse {
37     DeviceState parent_obj;
38     BlockBackend *blk;
39     bool blk_ro;
40     uint32_t *fuse32;
41 
42     DeviceState *dev;
43 
44     bool init_tbits;
45 
46     uint8_t efuse_nr;
47     uint32_t efuse_size;
48 
49     uint32_t *ro_bits;
50     uint32_t ro_bits_cnt;
51 };
52 
53 /**
54  * xlnx_efuse_calc_crc:
55  * @data: an array of 32-bit words for which the CRC should be computed
56  * @u32_cnt: the array size in number of 32-bit words
57  * @zpads: the number of 32-bit zeros prepended to @data before computation
58  *
59  * This function is used to compute the CRC for an array of 32-bit words,
60  * using a Xilinx-specific data padding.
61  *
62  * Returns: the computed 32-bit CRC
63  */
64 uint32_t xlnx_efuse_calc_crc(const uint32_t *data, unsigned u32_cnt,
65                              unsigned zpads);
66 
67 /**
68  * xlnx_efuse_get_bit:
69  * @s: the efuse object
70  * @bit: the efuse bit-address to read the data
71  *
72  * Returns: the bit, 0 or 1, at @bit of object @s
73  */
74 bool xlnx_efuse_get_bit(XlnxEFuse *s, unsigned int bit);
75 
76 /**
77  * xlnx_efuse_set_bit:
78  * @s: the efuse object
79  * @bit: the efuse bit-address to be written a value of 1
80  *
81  * Returns: true on success, false on failure
82  */
83 bool xlnx_efuse_set_bit(XlnxEFuse *s, unsigned int bit);
84 
85 /**
86  * xlnx_efuse_k256_check:
87  * @s: the efuse object
88  * @crc: the 32-bit CRC to be compared with
89  * @start: the efuse bit-address (which must be multiple of 32) of the
90  *         start of a 256-bit array
91  *
92  * This function computes the CRC of a 256-bit array starting at @start
93  * then compares to the given @crc
94  *
95  * Returns: true of @crc == computed, false otherwise
96  */
97 bool xlnx_efuse_k256_check(XlnxEFuse *s, uint32_t crc, unsigned start);
98 
99 /**
100  * xlnx_efuse_tbits_check:
101  * @s: the efuse object
102  *
103  * This function inspects a number of efuse bits at specific addresses
104  * to see if they match a validation pattern. Each pattern is a group
105  * of 4 bits, and there are 3 groups.
106  *
107  * Returns: a 3-bit mask, where a bit of '1' means the corresponding
108  * group has a valid pattern.
109  */
110 uint32_t xlnx_efuse_tbits_check(XlnxEFuse *s);
111 
112 /**
113  * xlnx_efuse_get_row:
114  * @s: the efuse object
115  * @bit: the efuse bit address for which a 32-bit value is read
116  *
117  * Returns: the entire 32 bits of the efuse, starting at a bit
118  * address that is multiple of 32 and contains the bit at @bit
119  */
120 static inline uint32_t xlnx_efuse_get_row(XlnxEFuse *s, unsigned int bit)
121 {
122     if (!(s->fuse32)) {
123         return 0;
124     } else {
125         unsigned int row_idx = bit / 32;
126 
127         assert(row_idx < (s->efuse_size * s->efuse_nr / 32));
128         return s->fuse32[row_idx];
129     }
130 }
131 
132 #endif
133