xref: /openbmc/u-boot/drivers/misc/mxc_ocotp.c (revision be059e88)
1 /*
2  * (C) Copyright 2013 ADVANSEE
3  * Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
4  *
5  * Based on Dirk Behme's
6  * https://github.com/dirkbehme/u-boot-imx6/blob/28b17e9/drivers/misc/imx_otp.c,
7  * which is based on Freescale's
8  * http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/drivers/misc/imx_otp.c?h=imx_v2009.08_1.1.0&id=9aa74e6,
9  * which is:
10  * Copyright (C) 2011 Freescale Semiconductor, Inc.
11  *
12  * SPDX-License-Identifier:	GPL-2.0+
13  */
14 
15 #include <common.h>
16 #include <fuse.h>
17 #include <linux/errno.h>
18 #include <asm/io.h>
19 #include <asm/arch/clock.h>
20 #include <asm/arch/imx-regs.h>
21 #include <asm/imx-common/sys_proto.h>
22 
23 #define BO_CTRL_WR_UNLOCK		16
24 #define BM_CTRL_WR_UNLOCK		0xffff0000
25 #define BV_CTRL_WR_UNLOCK_KEY		0x3e77
26 #define BM_CTRL_ERROR			0x00000200
27 #define BM_CTRL_BUSY			0x00000100
28 #define BO_CTRL_ADDR			0
29 #ifdef CONFIG_MX7
30 #define BM_CTRL_ADDR                    0x0000000f
31 #define BM_CTRL_RELOAD                  0x00000400
32 #else
33 #define BM_CTRL_ADDR			0x0000007f
34 #endif
35 
36 #ifdef CONFIG_MX7
37 #define BO_TIMING_FSOURCE               12
38 #define BM_TIMING_FSOURCE               0x0007f000
39 #define BV_TIMING_FSOURCE_NS            1001
40 #define BO_TIMING_PROG                  0
41 #define BM_TIMING_PROG                  0x00000fff
42 #define BV_TIMING_PROG_US               10
43 #else
44 #define BO_TIMING_STROBE_READ		16
45 #define BM_TIMING_STROBE_READ		0x003f0000
46 #define BV_TIMING_STROBE_READ_NS	37
47 #define BO_TIMING_RELAX			12
48 #define BM_TIMING_RELAX			0x0000f000
49 #define BV_TIMING_RELAX_NS		17
50 #define BO_TIMING_STROBE_PROG		0
51 #define BM_TIMING_STROBE_PROG		0x00000fff
52 #define BV_TIMING_STROBE_PROG_US	10
53 #endif
54 
55 #define BM_READ_CTRL_READ_FUSE		0x00000001
56 
57 #define BF(value, field)		(((value) << BO_##field) & BM_##field)
58 
59 #define WRITE_POSTAMBLE_US		2
60 
61 #if defined(CONFIG_MX6) || defined(CONFIG_VF610)
62 #define FUSE_BANK_SIZE	0x80
63 #ifdef CONFIG_MX6SL
64 #define FUSE_BANKS	8
65 #elif defined(CONFIG_MX6ULL) || defined(CONFIG_MX6SLL)
66 #define FUSE_BANKS	9
67 #else
68 #define FUSE_BANKS	16
69 #endif
70 #elif defined CONFIG_MX7
71 #define FUSE_BANK_SIZE	0x40
72 #define FUSE_BANKS	16
73 #else
74 #error "Unsupported architecture\n"
75 #endif
76 
77 #if defined(CONFIG_MX6)
78 
79 /*
80  * There is a hole in shadow registers address map of size 0x100
81  * between bank 5 and bank 6 on iMX6QP, iMX6DQ, iMX6SDL, iMX6SX,
82  * iMX6UL, i.MX6ULL and i.MX6SLL.
83  * Bank 5 ends at 0x6F0 and Bank 6 starts at 0x800. When reading the fuses,
84  * we should account for this hole in address space.
85  *
86  * Similar hole exists between bank 14 and bank 15 of size
87  * 0x80 on iMX6QP, iMX6DQ, iMX6SDL and iMX6SX.
88  * Note: iMX6SL has only 0-7 banks and there is no hole.
89  * Note: iMX6UL doesn't have this one.
90  *
91  * This function is to covert user input to physical bank index.
92  * Only needed when read fuse, because we use register offset, so
93  * need to calculate real register offset.
94  * When write, no need to consider hole, always use the bank/word
95  * index from fuse map.
96  */
97 u32 fuse_bank_physical(int index)
98 {
99 	u32 phy_index;
100 
101 	if (is_mx6sl()) {
102 		phy_index = index;
103 	} else if (is_mx6ul() || is_mx6ull() || is_mx6sll()) {
104 		if ((is_mx6ull() || is_mx6sll()) && index == 8)
105 			index = 7;
106 
107 		if (index >= 6)
108 			phy_index = fuse_bank_physical(5) + (index - 6) + 3;
109 		else
110 			phy_index = index;
111 	} else {
112 		if (index >= 15)
113 			phy_index = fuse_bank_physical(14) + (index - 15) + 2;
114 		else if (index >= 6)
115 			phy_index = fuse_bank_physical(5) + (index - 6) + 3;
116 		else
117 			phy_index = index;
118 	}
119 	return phy_index;
120 }
121 
122 u32 fuse_word_physical(u32 bank, u32 word_index)
123 {
124 	if (is_mx6ull() || is_mx6sll()) {
125 		if (bank == 8)
126 			word_index = word_index + 4;
127 	}
128 
129 	return word_index;
130 }
131 #else
132 u32 fuse_bank_physical(int index)
133 {
134 	return index;
135 }
136 
137 u32 fuse_word_physical(u32 bank, u32 word_index)
138 {
139 	return word_index;
140 }
141 
142 #endif
143 
144 static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us)
145 {
146 	while (readl(&regs->ctrl) & BM_CTRL_BUSY)
147 		udelay(delay_us);
148 }
149 
150 static void clear_error(struct ocotp_regs *regs)
151 {
152 	writel(BM_CTRL_ERROR, &regs->ctrl_clr);
153 }
154 
155 static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
156 				int assert, const char *caller)
157 {
158 	*regs = (struct ocotp_regs *)OCOTP_BASE_ADDR;
159 
160 	if (bank >= FUSE_BANKS ||
161 	    word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
162 	    !assert) {
163 		printf("mxc_ocotp %s(): Invalid argument\n", caller);
164 		return -EINVAL;
165 	}
166 
167 	if (is_mx6ull() || is_mx6sll()) {
168 		if ((bank == 7 || bank == 8) &&
169 		    word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 3) {
170 			printf("mxc_ocotp %s(): Invalid argument\n", caller);
171 			return -EINVAL;
172 		}
173 	}
174 
175 	enable_ocotp_clk(1);
176 
177 	wait_busy(*regs, 1);
178 	clear_error(*regs);
179 
180 	return 0;
181 }
182 
183 static int finish_access(struct ocotp_regs *regs, const char *caller)
184 {
185 	u32 err;
186 
187 	err = !!(readl(&regs->ctrl) & BM_CTRL_ERROR);
188 	clear_error(regs);
189 
190 	if (err) {
191 		printf("mxc_ocotp %s(): Access protect error\n", caller);
192 		return -EIO;
193 	}
194 
195 	return 0;
196 }
197 
198 static int prepare_read(struct ocotp_regs **regs, u32 bank, u32 word, u32 *val,
199 			const char *caller)
200 {
201 	return prepare_access(regs, bank, word, val != NULL, caller);
202 }
203 
204 int fuse_read(u32 bank, u32 word, u32 *val)
205 {
206 	struct ocotp_regs *regs;
207 	int ret;
208 	u32 phy_bank;
209 	u32 phy_word;
210 
211 	ret = prepare_read(&regs, bank, word, val, __func__);
212 	if (ret)
213 		return ret;
214 
215 	phy_bank = fuse_bank_physical(bank);
216 	phy_word = fuse_word_physical(bank, word);
217 
218 	*val = readl(&regs->bank[phy_bank].fuse_regs[phy_word << 2]);
219 
220 	return finish_access(regs, __func__);
221 }
222 
223 #ifdef CONFIG_MX7
224 static void set_timing(struct ocotp_regs *regs)
225 {
226 	u32 ipg_clk;
227 	u32 fsource, prog;
228 	u32 timing;
229 
230 	ipg_clk = mxc_get_clock(MXC_IPG_CLK);
231 
232 	fsource = DIV_ROUND_UP((ipg_clk / 1000) * BV_TIMING_FSOURCE_NS,
233 			+       1000000) + 1;
234 	prog = DIV_ROUND_CLOSEST(ipg_clk * BV_TIMING_PROG_US, 1000000) + 1;
235 
236 	timing = BF(fsource, TIMING_FSOURCE) | BF(prog, TIMING_PROG);
237 
238 	clrsetbits_le32(&regs->timing, BM_TIMING_FSOURCE | BM_TIMING_PROG,
239 			timing);
240 }
241 #else
242 static void set_timing(struct ocotp_regs *regs)
243 {
244 	u32 ipg_clk;
245 	u32 relax, strobe_read, strobe_prog;
246 	u32 timing;
247 
248 	ipg_clk = mxc_get_clock(MXC_IPG_CLK);
249 
250 	relax = DIV_ROUND_UP(ipg_clk * BV_TIMING_RELAX_NS, 1000000000) - 1;
251 	strobe_read = DIV_ROUND_UP(ipg_clk * BV_TIMING_STROBE_READ_NS,
252 					1000000000) + 2 * (relax + 1) - 1;
253 	strobe_prog = DIV_ROUND_CLOSEST(ipg_clk * BV_TIMING_STROBE_PROG_US,
254 						1000000) + 2 * (relax + 1) - 1;
255 
256 	timing = BF(strobe_read, TIMING_STROBE_READ) |
257 			BF(relax, TIMING_RELAX) |
258 			BF(strobe_prog, TIMING_STROBE_PROG);
259 
260 	clrsetbits_le32(&regs->timing, BM_TIMING_STROBE_READ | BM_TIMING_RELAX |
261 			BM_TIMING_STROBE_PROG, timing);
262 }
263 #endif
264 
265 static void setup_direct_access(struct ocotp_regs *regs, u32 bank, u32 word,
266 				int write)
267 {
268 	u32 wr_unlock = write ? BV_CTRL_WR_UNLOCK_KEY : 0;
269 #ifdef CONFIG_MX7
270 	u32 addr = bank;
271 #else
272 	u32 addr;
273 	/* Bank 7 and Bank 8 only supports 4 words each for i.MX6ULL */
274 	if ((is_mx6ull() || is_mx6sll()) && (bank > 7)) {
275 		bank = bank - 1;
276 		word += 4;
277 	}
278 	addr = bank << 3 | word;
279 #endif
280 
281 	set_timing(regs);
282 	clrsetbits_le32(&regs->ctrl, BM_CTRL_WR_UNLOCK | BM_CTRL_ADDR,
283 			BF(wr_unlock, CTRL_WR_UNLOCK) |
284 			BF(addr, CTRL_ADDR));
285 }
286 
287 int fuse_sense(u32 bank, u32 word, u32 *val)
288 {
289 	struct ocotp_regs *regs;
290 	int ret;
291 
292 	ret = prepare_read(&regs, bank, word, val, __func__);
293 	if (ret)
294 		return ret;
295 
296 	setup_direct_access(regs, bank, word, false);
297 	writel(BM_READ_CTRL_READ_FUSE, &regs->read_ctrl);
298 	wait_busy(regs, 1);
299 #ifdef CONFIG_MX7
300 	*val = readl((&regs->read_fuse_data0) + (word << 2));
301 #else
302 	*val = readl(&regs->read_fuse_data);
303 #endif
304 
305 	return finish_access(regs, __func__);
306 }
307 
308 static int prepare_write(struct ocotp_regs **regs, u32 bank, u32 word,
309 				const char *caller)
310 {
311 	return prepare_access(regs, bank, word, true, caller);
312 }
313 
314 int fuse_prog(u32 bank, u32 word, u32 val)
315 {
316 	struct ocotp_regs *regs;
317 	int ret;
318 
319 	ret = prepare_write(&regs, bank, word, __func__);
320 	if (ret)
321 		return ret;
322 
323 	setup_direct_access(regs, bank, word, true);
324 #ifdef CONFIG_MX7
325 	switch (word) {
326 	case 0:
327 		writel(0, &regs->data1);
328 		writel(0, &regs->data2);
329 		writel(0, &regs->data3);
330 		writel(val, &regs->data0);
331 		break;
332 	case 1:
333 		writel(val, &regs->data1);
334 		writel(0, &regs->data2);
335 		writel(0, &regs->data3);
336 		writel(0, &regs->data0);
337 		break;
338 	case 2:
339 		writel(0, &regs->data1);
340 		writel(val, &regs->data2);
341 		writel(0, &regs->data3);
342 		writel(0, &regs->data0);
343 		break;
344 	case 3:
345 		writel(0, &regs->data1);
346 		writel(0, &regs->data2);
347 		writel(val, &regs->data3);
348 		writel(0, &regs->data0);
349 		break;
350 	}
351 	wait_busy(regs, BV_TIMING_PROG_US);
352 #else
353 	writel(val, &regs->data);
354 	wait_busy(regs, BV_TIMING_STROBE_PROG_US);
355 #endif
356 	udelay(WRITE_POSTAMBLE_US);
357 
358 	return finish_access(regs, __func__);
359 }
360 
361 int fuse_override(u32 bank, u32 word, u32 val)
362 {
363 	struct ocotp_regs *regs;
364 	int ret;
365 	u32 phy_bank;
366 	u32 phy_word;
367 
368 	ret = prepare_write(&regs, bank, word, __func__);
369 	if (ret)
370 		return ret;
371 
372 	phy_bank = fuse_bank_physical(bank);
373 	phy_word = fuse_word_physical(bank, word);
374 
375 	writel(val, &regs->bank[phy_bank].fuse_regs[phy_word << 2]);
376 
377 	return finish_access(regs, __func__);
378 }
379