1 /*
2 * Copyright (C) 2015-2016 Reinhard Pfau <reinhard.pfau@gdsys.cc>
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7 #include <config.h>
8 #include <common.h>
9 #include <errno.h>
10 #include <asm/io.h>
11 #include <asm/arch/cpu.h>
12 #include <asm/arch/efuse.h>
13 #include <asm/arch/soc.h>
14 #include <linux/mbus.h>
15
16 #if defined(CONFIG_MVEBU_EFUSE_FAKE)
17 #define DRY_RUN
18 #else
19 #undef DRY_RUN
20 #endif
21
22 #define MBUS_EFUSE_BASE 0xF6000000
23 #define MBUS_EFUSE_SIZE BIT(20)
24
25 #define MVEBU_EFUSE_CONTROL (MVEBU_REGISTER(0xE4008))
26
27 enum {
28 MVEBU_EFUSE_CTRL_PROGRAM_ENABLE = (1 << 31),
29 };
30
31 struct mvebu_hd_efuse {
32 u32 bits_31_0;
33 u32 bits_63_32;
34 u32 bit64;
35 u32 reserved0;
36 };
37
38 #ifndef DRY_RUN
39 static struct mvebu_hd_efuse *efuses =
40 (struct mvebu_hd_efuse *)(MBUS_EFUSE_BASE + 0xF9000);
41 #else
42 static struct mvebu_hd_efuse efuses[EFUSE_LINE_MAX + 1];
43 #endif
44
45 static int efuse_initialised;
46
get_efuse_line(int nr)47 static struct mvebu_hd_efuse *get_efuse_line(int nr)
48 {
49 if (nr < 0 || nr > 63 || !efuse_initialised)
50 return NULL;
51
52 return efuses + nr;
53 }
54
enable_efuse_program(void)55 static void enable_efuse_program(void)
56 {
57 #ifndef DRY_RUN
58 setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
59 #endif
60 }
61
disable_efuse_program(void)62 static void disable_efuse_program(void)
63 {
64 #ifndef DRY_RUN
65 clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
66 #endif
67 }
68
do_prog_efuse(struct mvebu_hd_efuse * efuse,struct efuse_val * new_val,u32 mask0,u32 mask1)69 static int do_prog_efuse(struct mvebu_hd_efuse *efuse,
70 struct efuse_val *new_val, u32 mask0, u32 mask1)
71 {
72 struct efuse_val val;
73
74 val.dwords.d[0] = readl(&efuse->bits_31_0);
75 val.dwords.d[1] = readl(&efuse->bits_63_32);
76 val.lock = readl(&efuse->bit64);
77
78 if (val.lock & 1)
79 return -EPERM;
80
81 val.dwords.d[0] |= (new_val->dwords.d[0] & mask0);
82 val.dwords.d[1] |= (new_val->dwords.d[1] & mask1);
83 val.lock |= new_val->lock;
84
85 writel(val.dwords.d[0], &efuse->bits_31_0);
86 mdelay(1);
87 writel(val.dwords.d[1], &efuse->bits_63_32);
88 mdelay(1);
89 writel(val.lock, &efuse->bit64);
90 mdelay(5);
91
92 return 0;
93 }
94
prog_efuse(int nr,struct efuse_val * new_val,u32 mask0,u32 mask1)95 static int prog_efuse(int nr, struct efuse_val *new_val, u32 mask0, u32 mask1)
96 {
97 struct mvebu_hd_efuse *efuse;
98 int res = 0;
99
100 res = mvebu_efuse_init_hw();
101 if (res)
102 return res;
103
104 efuse = get_efuse_line(nr);
105 if (!efuse)
106 return -ENODEV;
107
108 if (!new_val)
109 return -EINVAL;
110
111 /* only write a fuse line with lock bit */
112 if (!new_val->lock)
113 return -EINVAL;
114
115 /* according to specs ECC protection bits must be 0 on write */
116 if (new_val->bytes.d[7] & 0xFE)
117 return -EINVAL;
118
119 if (!new_val->dwords.d[0] && !new_val->dwords.d[1] && (mask0 | mask1))
120 return 0;
121
122 enable_efuse_program();
123
124 res = do_prog_efuse(efuse, new_val, mask0, mask1);
125
126 disable_efuse_program();
127
128 return res;
129 }
130
mvebu_efuse_init_hw(void)131 int mvebu_efuse_init_hw(void)
132 {
133 int ret;
134
135 if (efuse_initialised)
136 return 0;
137
138 ret = mvebu_mbus_add_window_by_id(
139 CPU_TARGET_SATA23_DFX, 0xA, MBUS_EFUSE_BASE, MBUS_EFUSE_SIZE);
140
141 if (ret)
142 return ret;
143
144 efuse_initialised = 1;
145
146 return 0;
147 }
148
mvebu_read_efuse(int nr,struct efuse_val * val)149 int mvebu_read_efuse(int nr, struct efuse_val *val)
150 {
151 struct mvebu_hd_efuse *efuse;
152 int res;
153
154 res = mvebu_efuse_init_hw();
155 if (res)
156 return res;
157
158 efuse = get_efuse_line(nr);
159 if (!efuse)
160 return -ENODEV;
161
162 if (!val)
163 return -EINVAL;
164
165 val->dwords.d[0] = readl(&efuse->bits_31_0);
166 val->dwords.d[1] = readl(&efuse->bits_63_32);
167 val->lock = readl(&efuse->bit64);
168 return 0;
169 }
170
mvebu_write_efuse(int nr,struct efuse_val * val)171 int mvebu_write_efuse(int nr, struct efuse_val *val)
172 {
173 return prog_efuse(nr, val, ~0, ~0);
174 }
175
mvebu_lock_efuse(int nr)176 int mvebu_lock_efuse(int nr)
177 {
178 struct efuse_val val = {
179 .lock = 1,
180 };
181
182 return prog_efuse(nr, &val, 0, 0);
183 }
184
185 /*
186 * wrapper funcs providing the fuse API
187 *
188 * we use the following mapping:
189 * "bank" -> eFuse line
190 * "word" -> 0: bits 0-31
191 * 1: bits 32-63
192 * 2: bit 64 (lock)
193 */
194
195 static struct efuse_val prog_val;
196 static int valid_prog_words;
197
fuse_read(u32 bank,u32 word,u32 * val)198 int fuse_read(u32 bank, u32 word, u32 *val)
199 {
200 struct efuse_val fuse_line;
201 int res;
202
203 if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
204 return -EINVAL;
205
206 res = mvebu_read_efuse(bank, &fuse_line);
207 if (res)
208 return res;
209
210 if (word < 2)
211 *val = fuse_line.dwords.d[word];
212 else
213 *val = fuse_line.lock;
214
215 return res;
216 }
217
fuse_sense(u32 bank,u32 word,u32 * val)218 int fuse_sense(u32 bank, u32 word, u32 *val)
219 {
220 /* not supported */
221 return -ENOSYS;
222 }
223
fuse_prog(u32 bank,u32 word,u32 val)224 int fuse_prog(u32 bank, u32 word, u32 val)
225 {
226 int res = 0;
227
228 /*
229 * NOTE: Fuse line should be written as whole.
230 * So how can we do that with this API?
231 * For now: remember values for word == 0 and word == 1 and write the
232 * whole line when word == 2.
233 * This implies that we always require all 3 fuse prog cmds (one for
234 * for each word) to write a single fuse line.
235 * Exception is a single write to word 2 which will lock the fuse line.
236 *
237 * Hope that will be OK.
238 */
239
240 if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
241 return -EINVAL;
242
243 if (word < 2) {
244 prog_val.dwords.d[word] = val;
245 valid_prog_words |= (1 << word);
246 } else if ((valid_prog_words & 3) == 0 && val) {
247 res = mvebu_lock_efuse(bank);
248 valid_prog_words = 0;
249 } else if ((valid_prog_words & 3) != 3 || !val) {
250 res = -EINVAL;
251 } else {
252 prog_val.lock = val != 0;
253 res = mvebu_write_efuse(bank, &prog_val);
254 valid_prog_words = 0;
255 }
256
257 return res;
258 }
259
fuse_override(u32 bank,u32 word,u32 val)260 int fuse_override(u32 bank, u32 word, u32 val)
261 {
262 /* not supported */
263 return -ENOSYS;
264 }
265