summaryrefslogtreecommitdiff
path: root/drivers/mfd/ab3100-otp.c
blob: 8440010eb2b87b64f261d3dc87db955bebc737ea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
/*
 * drivers/mfd/ab3100_otp.c
 *
 * Copyright (C) 2007-2009 ST-Ericsson AB
 * License terms: GNU General Public License (GPL) version 2
 * Driver to read out OTP from the AB3100 Mixed-signal circuit
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mfd/abx500.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

/* The OTP registers */
#define AB3100_OTP0		0xb0
#define AB3100_OTP1		0xb1
#define AB3100_OTP2		0xb2
#define AB3100_OTP3		0xb3
#define AB3100_OTP4		0xb4
#define AB3100_OTP5		0xb5
#define AB3100_OTP6		0xb6
#define AB3100_OTP7		0xb7
#define AB3100_OTPP		0xbf

/**
 * struct ab3100_otp
 * @dev containing device
 * @locked whether the OTP is locked, after locking, no more bits
 *       can be changed but before locking it is still possible
 *       to change bits from 1->0.
 * @freq clocking frequency for the OTP, this frequency is either
 *       32768Hz or 1MHz/30
 * @paf product activation flag, indicates whether this is a real
 *       product (paf true) or a lab board etc (paf false)
 * @imeich if this is set it is possible to override the
 *       IMEI number found in the tac, fac and svn fields with
 *       (secured) software
 * @cid customer ID
 * @tac type allocation code of the IMEI
 * @fac final assembly code of the IMEI
 * @svn software version number of the IMEI
 * @debugfs a debugfs file used when dumping to file
 */
struct ab3100_otp {
	struct device *dev;
	bool locked;
	u32 freq;
	bool paf;
	bool imeich;
	u16 cid:14;
	u32 tac:20;
	u8 fac;
	u32 svn:20;
	struct dentry *debugfs;
};

static int __init ab3100_otp_read(struct ab3100_otp *otp)
{
	u8 otpval[8];
	u8 otpp;
	int err;

	err = abx500_get_register_interruptible(otp->dev, 0,
		AB3100_OTPP, &otpp);
	if (err) {
		dev_err(otp->dev, "unable to read OTPP register\n");
		return err;
	}

	err = abx500_get_register_page_interruptible(otp->dev, 0,
		AB3100_OTP0, otpval, 8);
	if (err) {
		dev_err(otp->dev, "unable to read OTP register page\n");
		return err;
	}

	/* Cache OTP properties, they never change by nature */
	otp->locked = (otpp & 0x80);
	otp->freq = (otpp & 0x40) ? 32768 : 34100;
	otp->paf = (otpval[1] & 0x80);
	otp->imeich = (otpval[1] & 0x40);
	otp->cid = ((otpval[1] << 8) | otpval[0]) & 0x3fff;
	otp->tac = ((otpval[4] & 0x0f) << 16) | (otpval[3] << 8) | otpval[2];
	otp->fac = ((otpval[5] & 0x0f) << 4) | (otpval[4] >> 4);
	otp->svn = (otpval[7] << 12) | (otpval[6] << 4) | (otpval[5] >> 4);
	return 0;
}

/*
 * This is a simple debugfs human-readable file that dumps out
 * the contents of the OTP.
 */
#ifdef CONFIG_DEBUG_FS
static int ab3100_show_otp(struct seq_file *s, void *v)
{
	struct ab3100_otp *otp = s->private;

	seq_printf(s, "OTP is %s\n", otp->locked ? "LOCKED" : "UNLOCKED");
	seq_printf(s, "OTP clock switch startup is %uHz\n", otp->freq);
	seq_printf(s, "PAF is %s\n", otp->paf ? "SET" : "NOT SET");
	seq_printf(s, "IMEI is %s\n", otp->imeich ?
		   "CHANGEABLE" : "NOT CHANGEABLE");
	seq_printf(s, "CID: 0x%04x (decimal: %d)\n", otp->cid, otp->cid);
	seq_printf(s, "IMEI: %u-%u-%u\n", otp->tac, otp->fac, otp->svn);
	return 0;
}

static int ab3100_otp_open(struct inode *inode, struct file *file)
{
	return single_open(file, ab3100_show_otp, inode->i_private);
}

static const struct file_operations ab3100_otp_operations = {
	.open		= ab3100_otp_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int __init ab3100_otp_init_debugfs(struct device *dev,
					  struct ab3100_otp *otp)
{
	otp->debugfs = debugfs_create_file("ab3100_otp", S_IFREG | S_IRUGO,
					   NULL, otp,
					   &ab3100_otp_operations);
	if (!otp->debugfs) {
		dev_err(dev, "AB3100 debugfs OTP file registration failed!\n");
		return -ENOENT;
	}
	return 0;
}

static void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
{
	debugfs_remove(otp->debugfs);
}
#else
/* Compile this out if debugfs not selected */
static inline int __init ab3100_otp_init_debugfs(struct device *dev,
						 struct ab3100_otp *otp)
{
	return 0;
}

static inline void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
{
}
#endif

#define SHOW_AB3100_ATTR(name) \
static ssize_t ab3100_otp_##name##_show(struct device *dev, \
			       struct device_attribute *attr, \
			       char *buf) \
{\
	struct ab3100_otp *otp = dev_get_drvdata(dev); \
	return sprintf(buf, "%u\n", otp->name); \
}

SHOW_AB3100_ATTR(locked)
SHOW_AB3100_ATTR(freq)
SHOW_AB3100_ATTR(paf)
SHOW_AB3100_ATTR(imeich)
SHOW_AB3100_ATTR(cid)
SHOW_AB3100_ATTR(fac)
SHOW_AB3100_ATTR(tac)
SHOW_AB3100_ATTR(svn)

static struct device_attribute ab3100_otp_attrs[] = {
	__ATTR(locked, S_IRUGO, ab3100_otp_locked_show, NULL),
	__ATTR(freq, S_IRUGO, ab3100_otp_freq_show, NULL),
	__ATTR(paf, S_IRUGO, ab3100_otp_paf_show, NULL),
	__ATTR(imeich, S_IRUGO, ab3100_otp_imeich_show, NULL),
	__ATTR(cid, S_IRUGO, ab3100_otp_cid_show, NULL),
	__ATTR(fac, S_IRUGO, ab3100_otp_fac_show, NULL),
	__ATTR(tac, S_IRUGO, ab3100_otp_tac_show, NULL),
	__ATTR(svn, S_IRUGO, ab3100_otp_svn_show, NULL),
};

static int __init ab3100_otp_probe(struct platform_device *pdev)
{
	struct ab3100_otp *otp;
	int err = 0;
	int i;

	otp = kzalloc(sizeof(struct ab3100_otp), GFP_KERNEL);
	if (!otp) {
		dev_err(&pdev->dev, "could not allocate AB3100 OTP device\n");
		return -ENOMEM;
	}
	otp->dev = &pdev->dev;

	/* Replace platform data coming in with a local struct */
	platform_set_drvdata(pdev, otp);

	err = ab3100_otp_read(otp);
	if (err)
		goto err_otp_read;

	dev_info(&pdev->dev, "AB3100 OTP readout registered\n");

	/* sysfs entries */
	for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) {
		err = device_create_file(&pdev->dev,
					 &ab3100_otp_attrs[i]);
		if (err)
			goto err_create_file;
	}

	/* debugfs entries */
	err = ab3100_otp_init_debugfs(&pdev->dev, otp);
	if (err)
		goto err_init_debugfs;

	return 0;

err_init_debugfs:
err_create_file:
	while (--i >= 0)
		device_remove_file(&pdev->dev, &ab3100_otp_attrs[i]);
err_otp_read:
	kfree(otp);
	return err;
}

static int __exit ab3100_otp_remove(struct platform_device *pdev)
{
	struct ab3100_otp *otp = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
		device_remove_file(&pdev->dev,
				   &ab3100_otp_attrs[i]);
	ab3100_otp_exit_debugfs(otp);
	kfree(otp);
	return 0;
}

static struct platform_driver ab3100_otp_driver = {
	.driver = {
		.name = "ab3100-otp",
		.owner = THIS_MODULE,
	},
	.remove	 = __exit_p(ab3100_otp_remove),
};

static int __init ab3100_otp_init(void)
{
	return platform_driver_probe(&ab3100_otp_driver,
				     ab3100_otp_probe);
}

static void __exit ab3100_otp_exit(void)
{
	platform_driver_unregister(&ab3100_otp_driver);
}

module_init(ab3100_otp_init);
module_exit(ab3100_otp_exit);

MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("AB3100 OTP Readout Driver");
MODULE_LICENSE("GPL");