1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2015-2016 Reinhard Pfau <reinhard.pfau@gdsys.cc>
4 */
5
6 #include <config.h>
7 #include <common.h>
8 #include <errno.h>
9 #include <asm/io.h>
10 #include <asm/arch/cpu.h>
11 #include <asm/arch/efuse.h>
12 #include <asm/arch/soc.h>
13 #include <linux/mbus.h>
14
15 #if defined(CONFIG_MVEBU_EFUSE_FAKE)
16 #define DRY_RUN
17 #else
18 #undef DRY_RUN
19 #endif
20
21 #define MBUS_EFUSE_BASE 0xF6000000
22 #define MBUS_EFUSE_SIZE BIT(20)
23
24 #define MVEBU_EFUSE_CONTROL (MVEBU_REGISTER(0xE4008))
25
26 enum {
27 MVEBU_EFUSE_CTRL_PROGRAM_ENABLE = (1 << 31),
28 };
29
30 struct mvebu_hd_efuse {
31 u32 bits_31_0;
32 u32 bits_63_32;
33 u32 bit64;
34 u32 reserved0;
35 };
36
37 #ifndef DRY_RUN
38 static struct mvebu_hd_efuse *efuses =
39 (struct mvebu_hd_efuse *)(MBUS_EFUSE_BASE + 0xF9000);
40 #else
41 static struct mvebu_hd_efuse efuses[EFUSE_LINE_MAX + 1];
42 #endif
43
44 static int efuse_initialised;
45
get_efuse_line(int nr)46 static struct mvebu_hd_efuse *get_efuse_line(int nr)
47 {
48 if (nr < 0 || nr > 63 || !efuse_initialised)
49 return NULL;
50
51 return efuses + nr;
52 }
53
enable_efuse_program(void)54 static void enable_efuse_program(void)
55 {
56 #ifndef DRY_RUN
57 setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
58 #endif
59 }
60
disable_efuse_program(void)61 static void disable_efuse_program(void)
62 {
63 #ifndef DRY_RUN
64 clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
65 #endif
66 }
67
do_prog_efuse(struct mvebu_hd_efuse * efuse,struct efuse_val * new_val,u32 mask0,u32 mask1)68 static int do_prog_efuse(struct mvebu_hd_efuse *efuse,
69 struct efuse_val *new_val, u32 mask0, u32 mask1)
70 {
71 struct efuse_val val;
72
73 val.dwords.d[0] = readl(&efuse->bits_31_0);
74 val.dwords.d[1] = readl(&efuse->bits_63_32);
75 val.lock = readl(&efuse->bit64);
76
77 if (val.lock & 1)
78 return -EPERM;
79
80 val.dwords.d[0] |= (new_val->dwords.d[0] & mask0);
81 val.dwords.d[1] |= (new_val->dwords.d[1] & mask1);
82 val.lock |= new_val->lock;
83
84 writel(val.dwords.d[0], &efuse->bits_31_0);
85 mdelay(1);
86 writel(val.dwords.d[1], &efuse->bits_63_32);
87 mdelay(1);
88 writel(val.lock, &efuse->bit64);
89 mdelay(5);
90
91 return 0;
92 }
93
prog_efuse(int nr,struct efuse_val * new_val,u32 mask0,u32 mask1)94 static int prog_efuse(int nr, struct efuse_val *new_val, u32 mask0, u32 mask1)
95 {
96 struct mvebu_hd_efuse *efuse;
97 int res = 0;
98
99 res = mvebu_efuse_init_hw();
100 if (res)
101 return res;
102
103 efuse = get_efuse_line(nr);
104 if (!efuse)
105 return -ENODEV;
106
107 if (!new_val)
108 return -EINVAL;
109
110 /* only write a fuse line with lock bit */
111 if (!new_val->lock)
112 return -EINVAL;
113
114 /* according to specs ECC protection bits must be 0 on write */
115 if (new_val->bytes.d[7] & 0xFE)
116 return -EINVAL;
117
118 if (!new_val->dwords.d[0] && !new_val->dwords.d[1] && (mask0 | mask1))
119 return 0;
120
121 enable_efuse_program();
122
123 res = do_prog_efuse(efuse, new_val, mask0, mask1);
124
125 disable_efuse_program();
126
127 return res;
128 }
129
mvebu_efuse_init_hw(void)130 int mvebu_efuse_init_hw(void)
131 {
132 int ret;
133
134 if (efuse_initialised)
135 return 0;
136
137 ret = mvebu_mbus_add_window_by_id(
138 CPU_TARGET_SATA23_DFX, 0xA, MBUS_EFUSE_BASE, MBUS_EFUSE_SIZE);
139
140 if (ret)
141 return ret;
142
143 efuse_initialised = 1;
144
145 return 0;
146 }
147
mvebu_read_efuse(int nr,struct efuse_val * val)148 int mvebu_read_efuse(int nr, struct efuse_val *val)
149 {
150 struct mvebu_hd_efuse *efuse;
151 int res;
152
153 res = mvebu_efuse_init_hw();
154 if (res)
155 return res;
156
157 efuse = get_efuse_line(nr);
158 if (!efuse)
159 return -ENODEV;
160
161 if (!val)
162 return -EINVAL;
163
164 val->dwords.d[0] = readl(&efuse->bits_31_0);
165 val->dwords.d[1] = readl(&efuse->bits_63_32);
166 val->lock = readl(&efuse->bit64);
167 return 0;
168 }
169
mvebu_write_efuse(int nr,struct efuse_val * val)170 int mvebu_write_efuse(int nr, struct efuse_val *val)
171 {
172 return prog_efuse(nr, val, ~0, ~0);
173 }
174
mvebu_lock_efuse(int nr)175 int mvebu_lock_efuse(int nr)
176 {
177 struct efuse_val val = {
178 .lock = 1,
179 };
180
181 return prog_efuse(nr, &val, 0, 0);
182 }
183
184 /*
185 * wrapper funcs providing the fuse API
186 *
187 * we use the following mapping:
188 * "bank" -> eFuse line
189 * "word" -> 0: bits 0-31
190 * 1: bits 32-63
191 * 2: bit 64 (lock)
192 */
193
194 static struct efuse_val prog_val;
195 static int valid_prog_words;
196
fuse_read(u32 bank,u32 word,u32 * val)197 int fuse_read(u32 bank, u32 word, u32 *val)
198 {
199 struct efuse_val fuse_line;
200 int res;
201
202 if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
203 return -EINVAL;
204
205 res = mvebu_read_efuse(bank, &fuse_line);
206 if (res)
207 return res;
208
209 if (word < 2)
210 *val = fuse_line.dwords.d[word];
211 else
212 *val = fuse_line.lock;
213
214 return res;
215 }
216
fuse_sense(u32 bank,u32 word,u32 * val)217 int fuse_sense(u32 bank, u32 word, u32 *val)
218 {
219 /* not supported */
220 return -ENOSYS;
221 }
222
fuse_prog(u32 bank,u32 word,u32 val)223 int fuse_prog(u32 bank, u32 word, u32 val)
224 {
225 int res = 0;
226
227 /*
228 * NOTE: Fuse line should be written as whole.
229 * So how can we do that with this API?
230 * For now: remember values for word == 0 and word == 1 and write the
231 * whole line when word == 2.
232 * This implies that we always require all 3 fuse prog cmds (one for
233 * for each word) to write a single fuse line.
234 * Exception is a single write to word 2 which will lock the fuse line.
235 *
236 * Hope that will be OK.
237 */
238
239 if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
240 return -EINVAL;
241
242 if (word < 2) {
243 prog_val.dwords.d[word] = val;
244 valid_prog_words |= (1 << word);
245 } else if ((valid_prog_words & 3) == 0 && val) {
246 res = mvebu_lock_efuse(bank);
247 valid_prog_words = 0;
248 } else if ((valid_prog_words & 3) != 3 || !val) {
249 res = -EINVAL;
250 } else {
251 prog_val.lock = val != 0;
252 res = mvebu_write_efuse(bank, &prog_val);
253 valid_prog_words = 0;
254 }
255
256 return res;
257 }
258
fuse_override(u32 bank,u32 word,u32 val)259 int fuse_override(u32 bank, u32 word, u32 val)
260 {
261 /* not supported */
262 return -ENOSYS;
263 }
264