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 <asm/gpio.h>
14 #include <linux/bitops.h>
15 #include <linux/delay.h>
16 #include <linux/mbus.h>
17
18 #if defined(CONFIG_MVEBU_EFUSE_FAKE)
19 #define DRY_RUN
20 #else
21 #undef DRY_RUN
22 #endif
23
24 #define MBUS_EFUSE_BASE 0xF6000000
25 #define MBUS_EFUSE_SIZE BIT(20)
26
27 #define MVEBU_EFUSE_CONTROL (MVEBU_REGISTER(0xE4008))
28
29 enum {
30 MVEBU_EFUSE_CTRL_PROGRAM_ENABLE = (1 << 31),
31 MVEBU_EFUSE_LD1_SELECT = (1 << 6),
32 };
33
34 struct mvebu_hd_efuse {
35 u32 bits_31_0;
36 u32 bits_63_32;
37 u32 bit64;
38 u32 reserved0;
39 };
40
41 #ifndef DRY_RUN
42 static struct mvebu_hd_efuse *efuses =
43 (struct mvebu_hd_efuse *)(MBUS_EFUSE_BASE + 0xF9000);
44 static u32 *ld_efuses = (void *)MBUS_EFUSE_BASE + 0xF8F00;
45 #else
46 static struct mvebu_hd_efuse efuses[EFUSE_LINE_MAX + 1];
47 static u32 ld_efuses[EFUSE_LD_WORDS];
48 #endif
49
50 static int efuse_initialised;
51
get_efuse_line(int nr)52 static struct mvebu_hd_efuse *get_efuse_line(int nr)
53 {
54 if (nr < 0 || nr > 63 || !efuse_initialised)
55 return NULL;
56
57 return efuses + nr;
58 }
59
60 #ifndef DRY_RUN
61 static int vhv_gpio;
62 #endif
63
enable_efuse_program(void)64 static int enable_efuse_program(void)
65 {
66 #ifndef DRY_RUN
67 if (CONFIG_MVEBU_EFUSE_VHV_GPIO[0]) {
68 if (gpio_lookup_name(CONFIG_MVEBU_EFUSE_VHV_GPIO, NULL, NULL, &vhv_gpio)) {
69 printf("Error: VHV gpio lookup failed\n");
70 return -EOPNOTSUPP;
71 }
72 if (gpio_request(vhv_gpio, CONFIG_MVEBU_EFUSE_VHV_GPIO)) {
73 printf("Error: VHV gpio request failed\n");
74 return -EOPNOTSUPP;
75 }
76 if (gpio_direction_output(vhv_gpio,
77 IS_ENABLED(CONFIG_MVEBU_EFUSE_VHV_GPIO_ACTIVE_LOW) ? 0 : 1)) {
78 printf("Error: VHV gpio enable failed\n");
79 return -EINVAL;
80 }
81 mdelay(5); /* Wait for the VHV power to stabilize */
82 }
83
84 setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
85 #endif
86
87 return 0;
88 }
89
disable_efuse_program(void)90 static void disable_efuse_program(void)
91 {
92 #ifndef DRY_RUN
93 clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_CTRL_PROGRAM_ENABLE);
94
95 if (CONFIG_MVEBU_EFUSE_VHV_GPIO[0]) {
96 if (gpio_direction_output(vhv_gpio,
97 IS_ENABLED(CONFIG_MVEBU_EFUSE_VHV_GPIO_ACTIVE_LOW) ? 1 : 0))
98 printf("Error: VHV gpio disable failed\n");
99 gpio_free(vhv_gpio);
100 vhv_gpio = 0;
101 }
102 #endif
103 }
104
do_prog_efuse(struct mvebu_hd_efuse * efuse,struct efuse_val * new_val,u32 mask0,u32 mask1)105 static int do_prog_efuse(struct mvebu_hd_efuse *efuse,
106 struct efuse_val *new_val, u32 mask0, u32 mask1)
107 {
108 struct efuse_val val;
109
110 val.dwords.d[0] = readl(&efuse->bits_31_0);
111 val.dwords.d[1] = readl(&efuse->bits_63_32);
112 val.lock = readl(&efuse->bit64);
113
114 if (val.lock & 1)
115 return -EPERM;
116
117 val.dwords.d[0] |= (new_val->dwords.d[0] & mask0);
118 val.dwords.d[1] |= (new_val->dwords.d[1] & mask1);
119 val.lock |= new_val->lock;
120
121 writel(val.dwords.d[0], &efuse->bits_31_0);
122 mdelay(1);
123 writel(val.dwords.d[1], &efuse->bits_63_32);
124 mdelay(1);
125 writel(val.lock, &efuse->bit64);
126 mdelay(5);
127
128 return 0;
129 }
130
prog_efuse(int nr,struct efuse_val * new_val,u32 mask0,u32 mask1)131 static int prog_efuse(int nr, struct efuse_val *new_val, u32 mask0, u32 mask1)
132 {
133 struct mvebu_hd_efuse *efuse;
134 int res = 0;
135
136 res = mvebu_efuse_init_hw();
137 if (res)
138 return res;
139
140 efuse = get_efuse_line(nr);
141 if (!efuse)
142 return -ENODEV;
143
144 if (!new_val)
145 return -EINVAL;
146
147 /* only write a fuse line with lock bit */
148 if (!new_val->lock)
149 return -EINVAL;
150
151 /* according to specs ECC protection bits must be 0 on write */
152 if (new_val->bytes.d[7] & 0xFE)
153 return -EINVAL;
154
155 if (!new_val->dwords.d[0] && !new_val->dwords.d[1] && (mask0 | mask1))
156 return 0;
157
158 res = enable_efuse_program();
159 if (res)
160 return res;
161
162 res = do_prog_efuse(efuse, new_val, mask0, mask1);
163
164 disable_efuse_program();
165
166 return res;
167 }
168
mvebu_prog_ld_efuse(int ld1,u32 word,u32 val)169 int mvebu_prog_ld_efuse(int ld1, u32 word, u32 val)
170 {
171 int i, res;
172 u32 line[EFUSE_LD_WORDS];
173
174 res = mvebu_efuse_init_hw();
175 if (res)
176 return res;
177
178 mvebu_read_ld_efuse(ld1, line);
179
180 /* check if lock bit is already programmed */
181 if (line[EFUSE_LD_WORDS - 1])
182 return -EPERM;
183
184 /* check if word is valid */
185 if (word >= EFUSE_LD_WORDS)
186 return -EINVAL;
187
188 /* check if there is some bit for programming */
189 if (val == (line[word] & val))
190 return 0;
191
192 res = enable_efuse_program();
193 if (res)
194 return res;
195
196 mvebu_read_ld_efuse(ld1, line);
197 line[word] |= val;
198
199 for (i = 0; i < EFUSE_LD_WORDS; i++) {
200 writel(line[i], ld_efuses + i);
201 mdelay(1);
202 }
203
204 mdelay(5);
205
206 disable_efuse_program();
207
208 return 0;
209 }
210
mvebu_efuse_init_hw(void)211 int mvebu_efuse_init_hw(void)
212 {
213 int ret;
214
215 if (efuse_initialised)
216 return 0;
217
218 ret = mvebu_mbus_add_window_by_id(
219 CPU_TARGET_SATA23_DFX, 0xA, MBUS_EFUSE_BASE, MBUS_EFUSE_SIZE);
220
221 if (ret)
222 return ret;
223
224 efuse_initialised = 1;
225
226 return 0;
227 }
228
mvebu_read_efuse(int nr,struct efuse_val * val)229 int mvebu_read_efuse(int nr, struct efuse_val *val)
230 {
231 struct mvebu_hd_efuse *efuse;
232 int res;
233
234 res = mvebu_efuse_init_hw();
235 if (res)
236 return res;
237
238 efuse = get_efuse_line(nr);
239 if (!efuse)
240 return -ENODEV;
241
242 if (!val)
243 return -EINVAL;
244
245 val->dwords.d[0] = readl(&efuse->bits_31_0);
246 val->dwords.d[1] = readl(&efuse->bits_63_32);
247 val->lock = readl(&efuse->bit64);
248 return 0;
249 }
250
mvebu_read_ld_efuse(int ld1,u32 * line)251 void mvebu_read_ld_efuse(int ld1, u32 *line)
252 {
253 int i;
254
255 #ifndef DRY_RUN
256 if (ld1)
257 setbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_LD1_SELECT);
258 else
259 clrbits_le32(MVEBU_EFUSE_CONTROL, MVEBU_EFUSE_LD1_SELECT);
260 #endif
261
262 for (i = 0; i < EFUSE_LD_WORDS; i++)
263 line[i] = readl(ld_efuses + i);
264 }
265
mvebu_write_efuse(int nr,struct efuse_val * val)266 int mvebu_write_efuse(int nr, struct efuse_val *val)
267 {
268 return prog_efuse(nr, val, ~0, ~0);
269 }
270
mvebu_lock_efuse(int nr)271 int mvebu_lock_efuse(int nr)
272 {
273 struct efuse_val val = {
274 .lock = 1,
275 };
276
277 return prog_efuse(nr, &val, 0, 0);
278 }
279
280 /*
281 * wrapper funcs providing the fuse API
282 *
283 * we use the following mapping:
284 * "bank" -> eFuse line
285 * "word" -> 0: bits 0-31
286 * 1: bits 32-63
287 * 2: bit 64 (lock)
288 */
289
290 static struct efuse_val prog_val;
291 static int valid_prog_words;
292
fuse_read(u32 bank,u32 word,u32 * val)293 int fuse_read(u32 bank, u32 word, u32 *val)
294 {
295 struct efuse_val fuse_line;
296 u32 ld_line[EFUSE_LD_WORDS];
297 int res;
298
299 if ((bank == EFUSE_LD0_LINE || bank == EFUSE_LD1_LINE) && word < EFUSE_LD_WORDS) {
300 res = mvebu_efuse_init_hw();
301 if (res)
302 return res;
303 mvebu_read_ld_efuse(bank == EFUSE_LD1_LINE, ld_line);
304 *val = ld_line[word];
305 return 0;
306 }
307
308 if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
309 return -EINVAL;
310
311 res = mvebu_read_efuse(bank, &fuse_line);
312 if (res)
313 return res;
314
315 if (word < 2)
316 *val = fuse_line.dwords.d[word];
317 else
318 *val = fuse_line.lock;
319
320 return res;
321 }
322
fuse_sense(u32 bank,u32 word,u32 * val)323 int fuse_sense(u32 bank, u32 word, u32 *val)
324 {
325 /* not supported */
326 return -ENOSYS;
327 }
328
fuse_prog(u32 bank,u32 word,u32 val)329 int fuse_prog(u32 bank, u32 word, u32 val)
330 {
331 int res = 0;
332
333 if (bank == EFUSE_LD0_LINE || bank == EFUSE_LD1_LINE)
334 return mvebu_prog_ld_efuse(bank == EFUSE_LD1_LINE, word, val);
335
336 /*
337 * NOTE: Fuse line should be written as whole.
338 * So how can we do that with this API?
339 * For now: remember values for word == 0 and word == 1 and write the
340 * whole line when word == 2.
341 * This implies that we always require all 3 fuse prog cmds (one for
342 * for each word) to write a single fuse line.
343 * Exception is a single write to word 2 which will lock the fuse line.
344 *
345 * Hope that will be OK.
346 */
347
348 if (bank < EFUSE_LINE_MIN || bank > EFUSE_LINE_MAX || word > 2)
349 return -EINVAL;
350
351 if (word < 2) {
352 prog_val.dwords.d[word] = val;
353 valid_prog_words |= (1 << word);
354 } else if ((valid_prog_words & 3) == 0 && val) {
355 res = mvebu_lock_efuse(bank);
356 valid_prog_words = 0;
357 } else if ((valid_prog_words & 3) != 3 || !val) {
358 res = -EINVAL;
359 } else {
360 prog_val.lock = val != 0;
361 res = mvebu_write_efuse(bank, &prog_val);
362 valid_prog_words = 0;
363 }
364
365 return res;
366 }
367
fuse_override(u32 bank,u32 word,u32 val)368 int fuse_override(u32 bank, u32 word, u32 val)
369 {
370 /* not supported */
371 return -ENOSYS;
372 }
373