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Benoît Thébaudeau112fd2e2013-04-23 10:17:44 +00001/*
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 *
Wolfgang Denk1a459662013-07-08 09:37:19 +020012 * SPDX-License-Identifier: GPL-2.0+
Benoît Thébaudeau112fd2e2013-04-23 10:17:44 +000013 */
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#define BM_CTRL_ADDR 0x0000007f
29
30#define BO_TIMING_STROBE_READ 16
31#define BM_TIMING_STROBE_READ 0x003f0000
32#define BV_TIMING_STROBE_READ_NS 37
33#define BO_TIMING_RELAX 12
34#define BM_TIMING_RELAX 0x0000f000
35#define BV_TIMING_RELAX_NS 17
36#define BO_TIMING_STROBE_PROG 0
37#define BM_TIMING_STROBE_PROG 0x00000fff
38#define BV_TIMING_STROBE_PROG_US 10
39
40#define BM_READ_CTRL_READ_FUSE 0x00000001
41
42#define BF(value, field) (((value) << BO_##field) & BM_##field)
43
44#define WRITE_POSTAMBLE_US 2
45
46static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us)
47{
48 while (readl(&regs->ctrl) & BM_CTRL_BUSY)
49 udelay(delay_us);
50}
51
52static void clear_error(struct ocotp_regs *regs)
53{
54 writel(BM_CTRL_ERROR, &regs->ctrl_clr);
55}
56
57static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
58 int assert, const char *caller)
59{
60 *regs = (struct ocotp_regs *)OCOTP_BASE_ADDR;
61
62 if (bank >= ARRAY_SIZE((*regs)->bank) ||
63 word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
64 !assert) {
65 printf("mxc_ocotp %s(): Invalid argument\n", caller);
66 return -EINVAL;
67 }
68
69 enable_ocotp_clk(1);
70
71 wait_busy(*regs, 1);
72 clear_error(*regs);
73
74 return 0;
75}
76
77static int finish_access(struct ocotp_regs *regs, const char *caller)
78{
79 u32 err;
80
81 err = !!(readl(&regs->ctrl) & BM_CTRL_ERROR);
82 clear_error(regs);
83
Benoît Thébaudeau112fd2e2013-04-23 10:17:44 +000084 if (err) {
85 printf("mxc_ocotp %s(): Access protect error\n", caller);
86 return -EIO;
87 }
88
89 return 0;
90}
91
92static int prepare_read(struct ocotp_regs **regs, u32 bank, u32 word, u32 *val,
93 const char *caller)
94{
95 return prepare_access(regs, bank, word, val != NULL, caller);
96}
97
98int fuse_read(u32 bank, u32 word, u32 *val)
99{
100 struct ocotp_regs *regs;
101 int ret;
102
103 ret = prepare_read(&regs, bank, word, val, __func__);
104 if (ret)
105 return ret;
106
107 *val = readl(&regs->bank[bank].fuse_regs[word << 2]);
108
109 return finish_access(regs, __func__);
110}
111
112static void set_timing(struct ocotp_regs *regs)
113{
114 u32 ipg_clk;
115 u32 relax, strobe_read, strobe_prog;
116 u32 timing;
117
118 ipg_clk = mxc_get_clock(MXC_IPG_CLK);
119
120 relax = DIV_ROUND_UP(ipg_clk * BV_TIMING_RELAX_NS, 1000000000) - 1;
121 strobe_read = DIV_ROUND_UP(ipg_clk * BV_TIMING_STROBE_READ_NS,
122 1000000000) + 2 * (relax + 1) - 1;
Masahiro Yamada45159922014-11-07 03:03:26 +0900123 strobe_prog = DIV_ROUND_CLOSEST(ipg_clk * BV_TIMING_STROBE_PROG_US,
124 1000000) + 2 * (relax + 1) - 1;
Benoît Thébaudeau112fd2e2013-04-23 10:17:44 +0000125
126 timing = BF(strobe_read, TIMING_STROBE_READ) |
127 BF(relax, TIMING_RELAX) |
128 BF(strobe_prog, TIMING_STROBE_PROG);
129
130 clrsetbits_le32(&regs->timing, BM_TIMING_STROBE_READ | BM_TIMING_RELAX |
131 BM_TIMING_STROBE_PROG, timing);
132}
133
134static void setup_direct_access(struct ocotp_regs *regs, u32 bank, u32 word,
135 int write)
136{
137 u32 wr_unlock = write ? BV_CTRL_WR_UNLOCK_KEY : 0;
138 u32 addr = bank << 3 | word;
139
140 set_timing(regs);
141 clrsetbits_le32(&regs->ctrl, BM_CTRL_WR_UNLOCK | BM_CTRL_ADDR,
142 BF(wr_unlock, CTRL_WR_UNLOCK) |
143 BF(addr, CTRL_ADDR));
144}
145
146int fuse_sense(u32 bank, u32 word, u32 *val)
147{
148 struct ocotp_regs *regs;
149 int ret;
150
151 ret = prepare_read(&regs, bank, word, val, __func__);
152 if (ret)
153 return ret;
154
155 setup_direct_access(regs, bank, word, false);
156 writel(BM_READ_CTRL_READ_FUSE, &regs->read_ctrl);
157 wait_busy(regs, 1);
158 *val = readl(&regs->read_fuse_data);
159
160 return finish_access(regs, __func__);
161}
162
163static int prepare_write(struct ocotp_regs **regs, u32 bank, u32 word,
164 const char *caller)
165{
166 return prepare_access(regs, bank, word, true, caller);
167}
168
169int fuse_prog(u32 bank, u32 word, u32 val)
170{
171 struct ocotp_regs *regs;
172 int ret;
173
174 ret = prepare_write(&regs, bank, word, __func__);
175 if (ret)
176 return ret;
177
178 setup_direct_access(regs, bank, word, true);
179 writel(val, &regs->data);
180 wait_busy(regs, BV_TIMING_STROBE_PROG_US);
181 udelay(WRITE_POSTAMBLE_US);
182
183 return finish_access(regs, __func__);
184}
185
186int fuse_override(u32 bank, u32 word, u32 val)
187{
188 struct ocotp_regs *regs;
189 int ret;
190
191 ret = prepare_write(&regs, bank, word, __func__);
192 if (ret)
193 return ret;
194
195 writel(val, &regs->bank[bank].fuse_regs[word << 2]);
196
197 return finish_access(regs, __func__);
198}