xref: /openbmc/u-boot/drivers/misc/mxc_ocotp.c (revision 44da3a17)
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 <asm/errno.h>
18 #include <asm/io.h>
19 #include <asm/arch/clock.h>
20 #include <asm/arch/imx-regs.h>
21 
22 #define BO_CTRL_WR_UNLOCK		16
23 #define BM_CTRL_WR_UNLOCK		0xffff0000
24 #define BV_CTRL_WR_UNLOCK_KEY		0x3e77
25 #define BM_CTRL_ERROR			0x00000200
26 #define BM_CTRL_BUSY			0x00000100
27 #define BO_CTRL_ADDR			0
28 #ifdef CONFIG_MX7
29 #define BM_CTRL_ADDR                    0x0000000f
30 #define BM_CTRL_RELOAD                  0x00000400
31 #else
32 #define BM_CTRL_ADDR			0x0000007f
33 #endif
34 
35 #ifdef CONFIG_MX7
36 #define BO_TIMING_FSOURCE               12
37 #define BM_TIMING_FSOURCE               0x0007f000
38 #define BV_TIMING_FSOURCE_NS            1001
39 #define BO_TIMING_PROG                  0
40 #define BM_TIMING_PROG                  0x00000fff
41 #define BV_TIMING_PROG_US               10
42 #else
43 #define BO_TIMING_STROBE_READ		16
44 #define BM_TIMING_STROBE_READ		0x003f0000
45 #define BV_TIMING_STROBE_READ_NS	37
46 #define BO_TIMING_RELAX			12
47 #define BM_TIMING_RELAX			0x0000f000
48 #define BV_TIMING_RELAX_NS		17
49 #define BO_TIMING_STROBE_PROG		0
50 #define BM_TIMING_STROBE_PROG		0x00000fff
51 #define BV_TIMING_STROBE_PROG_US	10
52 #endif
53 
54 #define BM_READ_CTRL_READ_FUSE		0x00000001
55 
56 #define BF(value, field)		(((value) << BO_##field) & BM_##field)
57 
58 #define WRITE_POSTAMBLE_US		2
59 
60 #if defined(CONFIG_MX6) || defined(CONFIG_VF610)
61 #define FUSE_BANK_SIZE	0x80
62 #ifdef CONFIG_MX6SL
63 #define FUSE_BANKS	8
64 #else
65 #define FUSE_BANKS	16
66 #endif
67 #elif defined CONFIG_MX7
68 #define FUSE_BANK_SIZE	0x40
69 #define FUSE_BANKS	16
70 #else
71 #error "Unsupported architecture\n"
72 #endif
73 
74 #if defined(CONFIG_MX6)
75 #include <asm/arch/sys_proto.h>
76 
77 /*
78  * There is a hole in shadow registers address map of size 0x100
79  * between bank 5 and bank 6 on iMX6QP, iMX6DQ, iMX6SDL, iMX6SX and iMX6UL.
80  * Bank 5 ends at 0x6F0 and Bank 6 starts at 0x800. When reading the fuses,
81  * we should account for this hole in address space.
82  *
83  * Similar hole exists between bank 14 and bank 15 of size
84  * 0x80 on iMX6QP, iMX6DQ, iMX6SDL and iMX6SX.
85  * Note: iMX6SL has only 0-7 banks and there is no hole.
86  * Note: iMX6UL doesn't have this one.
87  *
88  * This function is to covert user input to physical bank index.
89  * Only needed when read fuse, because we use register offset, so
90  * need to calculate real register offset.
91  * When write, no need to consider hole, always use the bank/word
92  * index from fuse map.
93  */
94 u32 fuse_bank_physical(int index)
95 {
96 	u32 phy_index;
97 
98 	if (is_cpu_type(MXC_CPU_MX6SL)) {
99 		phy_index = index;
100 	} else if (is_cpu_type(MXC_CPU_MX6UL)) {
101 		if (index >= 6)
102 			phy_index = fuse_bank_physical(5) + (index - 6) + 3;
103 		else
104 			phy_index = index;
105 	} else {
106 		if (index >= 15)
107 			phy_index = fuse_bank_physical(14) + (index - 15) + 2;
108 		else if (index >= 6)
109 			phy_index = fuse_bank_physical(5) + (index - 6) + 3;
110 		else
111 			phy_index = index;
112 	}
113 	return phy_index;
114 }
115 #else
116 u32 fuse_bank_physical(int index)
117 {
118 	return index;
119 }
120 #endif
121 
122 static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us)
123 {
124 	while (readl(&regs->ctrl) & BM_CTRL_BUSY)
125 		udelay(delay_us);
126 }
127 
128 static void clear_error(struct ocotp_regs *regs)
129 {
130 	writel(BM_CTRL_ERROR, &regs->ctrl_clr);
131 }
132 
133 static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
134 				int assert, const char *caller)
135 {
136 	*regs = (struct ocotp_regs *)OCOTP_BASE_ADDR;
137 
138 	if (bank >= FUSE_BANKS ||
139 	    word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
140 	    !assert) {
141 		printf("mxc_ocotp %s(): Invalid argument\n", caller);
142 		return -EINVAL;
143 	}
144 
145 	enable_ocotp_clk(1);
146 
147 	wait_busy(*regs, 1);
148 	clear_error(*regs);
149 
150 	return 0;
151 }
152 
153 static int finish_access(struct ocotp_regs *regs, const char *caller)
154 {
155 	u32 err;
156 
157 	err = !!(readl(&regs->ctrl) & BM_CTRL_ERROR);
158 	clear_error(regs);
159 
160 	if (err) {
161 		printf("mxc_ocotp %s(): Access protect error\n", caller);
162 		return -EIO;
163 	}
164 
165 	return 0;
166 }
167 
168 static int prepare_read(struct ocotp_regs **regs, u32 bank, u32 word, u32 *val,
169 			const char *caller)
170 {
171 	return prepare_access(regs, bank, word, val != NULL, caller);
172 }
173 
174 int fuse_read(u32 bank, u32 word, u32 *val)
175 {
176 	struct ocotp_regs *regs;
177 	int ret;
178 	u32 phy_bank;
179 
180 	ret = prepare_read(&regs, bank, word, val, __func__);
181 	if (ret)
182 		return ret;
183 
184 	phy_bank = fuse_bank_physical(bank);
185 
186 	*val = readl(&regs->bank[phy_bank].fuse_regs[word << 2]);
187 
188 	return finish_access(regs, __func__);
189 }
190 
191 #ifdef CONFIG_MX7
192 static void set_timing(struct ocotp_regs *regs)
193 {
194 	u32 ipg_clk;
195 	u32 fsource, prog;
196 	u32 timing;
197 
198 	ipg_clk = mxc_get_clock(MXC_IPG_CLK);
199 
200 	fsource = DIV_ROUND_UP((ipg_clk / 1000) * BV_TIMING_FSOURCE_NS,
201 			+       1000000) + 1;
202 	prog = DIV_ROUND_CLOSEST(ipg_clk * BV_TIMING_PROG_US, 1000000) + 1;
203 
204 	timing = BF(fsource, TIMING_FSOURCE) | BF(prog, TIMING_PROG);
205 
206 	clrsetbits_le32(&regs->timing, BM_TIMING_FSOURCE | BM_TIMING_PROG,
207 			timing);
208 }
209 #else
210 static void set_timing(struct ocotp_regs *regs)
211 {
212 	u32 ipg_clk;
213 	u32 relax, strobe_read, strobe_prog;
214 	u32 timing;
215 
216 	ipg_clk = mxc_get_clock(MXC_IPG_CLK);
217 
218 	relax = DIV_ROUND_UP(ipg_clk * BV_TIMING_RELAX_NS, 1000000000) - 1;
219 	strobe_read = DIV_ROUND_UP(ipg_clk * BV_TIMING_STROBE_READ_NS,
220 					1000000000) + 2 * (relax + 1) - 1;
221 	strobe_prog = DIV_ROUND_CLOSEST(ipg_clk * BV_TIMING_STROBE_PROG_US,
222 						1000000) + 2 * (relax + 1) - 1;
223 
224 	timing = BF(strobe_read, TIMING_STROBE_READ) |
225 			BF(relax, TIMING_RELAX) |
226 			BF(strobe_prog, TIMING_STROBE_PROG);
227 
228 	clrsetbits_le32(&regs->timing, BM_TIMING_STROBE_READ | BM_TIMING_RELAX |
229 			BM_TIMING_STROBE_PROG, timing);
230 }
231 #endif
232 
233 static void setup_direct_access(struct ocotp_regs *regs, u32 bank, u32 word,
234 				int write)
235 {
236 	u32 wr_unlock = write ? BV_CTRL_WR_UNLOCK_KEY : 0;
237 #ifdef CONFIG_MX7
238 	u32 addr = bank;
239 #else
240 	u32 addr = bank << 3 | word;
241 #endif
242 
243 	set_timing(regs);
244 	clrsetbits_le32(&regs->ctrl, BM_CTRL_WR_UNLOCK | BM_CTRL_ADDR,
245 			BF(wr_unlock, CTRL_WR_UNLOCK) |
246 			BF(addr, CTRL_ADDR));
247 }
248 
249 int fuse_sense(u32 bank, u32 word, u32 *val)
250 {
251 	struct ocotp_regs *regs;
252 	int ret;
253 
254 	ret = prepare_read(&regs, bank, word, val, __func__);
255 	if (ret)
256 		return ret;
257 
258 	setup_direct_access(regs, bank, word, false);
259 	writel(BM_READ_CTRL_READ_FUSE, &regs->read_ctrl);
260 	wait_busy(regs, 1);
261 #ifdef CONFIG_MX7
262 	*val = readl((&regs->read_fuse_data0) + (word << 2));
263 #else
264 	*val = readl(&regs->read_fuse_data);
265 #endif
266 
267 	return finish_access(regs, __func__);
268 }
269 
270 static int prepare_write(struct ocotp_regs **regs, u32 bank, u32 word,
271 				const char *caller)
272 {
273 	return prepare_access(regs, bank, word, true, caller);
274 }
275 
276 int fuse_prog(u32 bank, u32 word, u32 val)
277 {
278 	struct ocotp_regs *regs;
279 	int ret;
280 
281 	ret = prepare_write(&regs, bank, word, __func__);
282 	if (ret)
283 		return ret;
284 
285 	setup_direct_access(regs, bank, word, true);
286 #ifdef CONFIG_MX7
287 	switch (word) {
288 	case 0:
289 		writel(0, &regs->data1);
290 		writel(0, &regs->data2);
291 		writel(0, &regs->data3);
292 		writel(val, &regs->data0);
293 		break;
294 	case 1:
295 		writel(val, &regs->data1);
296 		writel(0, &regs->data2);
297 		writel(0, &regs->data3);
298 		writel(0, &regs->data0);
299 		break;
300 	case 2:
301 		writel(0, &regs->data1);
302 		writel(val, &regs->data2);
303 		writel(0, &regs->data3);
304 		writel(0, &regs->data0);
305 		break;
306 	case 3:
307 		writel(0, &regs->data1);
308 		writel(0, &regs->data2);
309 		writel(val, &regs->data3);
310 		writel(0, &regs->data0);
311 		break;
312 	}
313 	wait_busy(regs, BV_TIMING_PROG_US);
314 #else
315 	writel(val, &regs->data);
316 	wait_busy(regs, BV_TIMING_STROBE_PROG_US);
317 #endif
318 	udelay(WRITE_POSTAMBLE_US);
319 
320 	return finish_access(regs, __func__);
321 }
322 
323 int fuse_override(u32 bank, u32 word, u32 val)
324 {
325 	struct ocotp_regs *regs;
326 	int ret;
327 	u32 phy_bank;
328 
329 	ret = prepare_write(&regs, bank, word, __func__);
330 	if (ret)
331 		return ret;
332 
333 	phy_bank = fuse_bank_physical(bank);
334 
335 	writel(val, &regs->bank[phy_bank].fuse_regs[word << 2]);
336 
337 	return finish_access(regs, __func__);
338 }
339