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
29enum {
30	MVEBU_EFUSE_CTRL_PROGRAM_ENABLE = (1 << 31),
31	MVEBU_EFUSE_LD1_SELECT          = (1 <<  6),
32};
33
34struct 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
42static struct mvebu_hd_efuse *efuses =
43	(struct mvebu_hd_efuse *)(MBUS_EFUSE_BASE + 0xF9000);
44static u32 *ld_efuses = (void *)MBUS_EFUSE_BASE + 0xF8F00;
45#else
46static struct mvebu_hd_efuse efuses[EFUSE_LINE_MAX + 1];
47static u32 ld_efuses[EFUSE_LD_WORDS];
48#endif
49
50static int efuse_initialised;
51
52static 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
61static int vhv_gpio;
62#endif
63
64static 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
90static 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
105static 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
131static 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
169int 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
211int 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
229int 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
251void 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
266int mvebu_write_efuse(int nr, struct efuse_val *val)
267{
268	return prog_efuse(nr, val, ~0, ~0);
269}
270
271int 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
290static struct efuse_val prog_val;
291static int valid_prog_words;
292
293int 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
323int fuse_sense(u32 bank, u32 word, u32 *val)
324{
325	/* not supported */
326	return -ENOSYS;
327}
328
329int 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
368int fuse_override(u32 bank, u32 word, u32 val)
369{
370	/* not supported */
371	return -ENOSYS;
372}
373