1/*
2 * drivers/mfd/ab3100_otp.c
3 *
4 * Copyright (C) 2007-2009 ST-Ericsson AB
5 * License terms: GNU General Public License (GPL) version 2
6 * Driver to read out OTP from the AB3100 Mixed-signal circuit
7 * Author: Linus Walleij <linus.walleij@stericsson.com>
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/slab.h>
13#include <linux/init.h>
14#include <linux/platform_device.h>
15#include <linux/mfd/abx500.h>
16#include <linux/debugfs.h>
17#include <linux/seq_file.h>
18
19/* The OTP registers */
20#define AB3100_OTP0 0xb0
21#define AB3100_OTP1 0xb1
22#define AB3100_OTP2 0xb2
23#define AB3100_OTP3 0xb3
24#define AB3100_OTP4 0xb4
25#define AB3100_OTP5 0xb5
26#define AB3100_OTP6 0xb6
27#define AB3100_OTP7 0xb7
28#define AB3100_OTPP 0xbf
29
30/**
31 * struct ab3100_otp
32 * @dev containing device
33 * @locked whether the OTP is locked, after locking, no more bits
34 * can be changed but before locking it is still possible
35 * to change bits from 1->0.
36 * @freq clocking frequency for the OTP, this frequency is either
37 * 32768Hz or 1MHz/30
38 * @paf product activation flag, indicates whether this is a real
39 * product (paf true) or a lab board etc (paf false)
40 * @imeich if this is set it is possible to override the
41 * IMEI number found in the tac, fac and svn fields with
42 * (secured) software
43 * @cid customer ID
44 * @tac type allocation code of the IMEI
45 * @fac final assembly code of the IMEI
46 * @svn software version number of the IMEI
47 * @debugfs a debugfs file used when dumping to file
48 */
49struct ab3100_otp {
50 struct device *dev;
51 bool locked;
52 u32 freq;
53 bool paf;
54 bool imeich;
55 u16 cid:14;
56 u32 tac:20;
57 u8 fac;
58 u32 svn:20;
59 struct dentry *debugfs;
60};
61
62static int __init ab3100_otp_read(struct ab3100_otp *otp)
63{
64 u8 otpval[8];
65 u8 otpp;
66 int err;
67
68 err = abx500_get_register_interruptible(otp->dev, 0,
69 AB3100_OTPP, &otpp);
70 if (err) {
71 dev_err(otp->dev, "unable to read OTPP register\n");
72 return err;
73 }
74
75 err = abx500_get_register_page_interruptible(otp->dev, 0,
76 AB3100_OTP0, otpval, 8);
77 if (err) {
78 dev_err(otp->dev, "unable to read OTP register page\n");
79 return err;
80 }
81
82 /* Cache OTP properties, they never change by nature */
83 otp->locked = (otpp & 0x80);
84 otp->freq = (otpp & 0x40) ? 32768 : 34100;
85 otp->paf = (otpval[1] & 0x80);
86 otp->imeich = (otpval[1] & 0x40);
87 otp->cid = ((otpval[1] << 8) | otpval[0]) & 0x3fff;
88 otp->tac = ((otpval[4] & 0x0f) << 16) | (otpval[3] << 8) | otpval[2];
89 otp->fac = ((otpval[5] & 0x0f) << 4) | (otpval[4] >> 4);
90 otp->svn = (otpval[7] << 12) | (otpval[6] << 4) | (otpval[5] >> 4);
91 return 0;
92}
93
94/*
95 * This is a simple debugfs human-readable file that dumps out
96 * the contents of the OTP.
97 */
98#ifdef CONFIG_DEBUG_FS
99static int ab3100_show_otp(struct seq_file *s, void *v)
100{
101 struct ab3100_otp *otp = s->private;
102
103 seq_printf(s, "OTP is %s\n", otp->locked ? "LOCKED" : "UNLOCKED");
104 seq_printf(s, "OTP clock switch startup is %uHz\n", otp->freq);
105 seq_printf(s, "PAF is %s\n", otp->paf ? "SET" : "NOT SET");
106 seq_printf(s, "IMEI is %s\n", otp->imeich ?
107 "CHANGEABLE" : "NOT CHANGEABLE");
108 seq_printf(s, "CID: 0x%04x (decimal: %d)\n", otp->cid, otp->cid);
109 seq_printf(s, "IMEI: %u-%u-%u\n", otp->tac, otp->fac, otp->svn);
110 return 0;
111}
112
113static int ab3100_otp_open(struct inode *inode, struct file *file)
114{
115 return single_open(file, ab3100_show_otp, inode->i_private);
116}
117
118static const struct file_operations ab3100_otp_operations = {
119 .open = ab3100_otp_open,
120 .read = seq_read,
121 .llseek = seq_lseek,
122 .release = single_release,
123};
124
125static int __init ab3100_otp_init_debugfs(struct device *dev,
126 struct ab3100_otp *otp)
127{
128 otp->debugfs = debugfs_create_file("ab3100_otp", S_IFREG | S_IRUGO,
129 NULL, otp,
130 &ab3100_otp_operations);
131 if (!otp->debugfs) {
132 dev_err(dev, "AB3100 debugfs OTP file registration failed!\n");
133 return -ENOENT;
134 }
135 return 0;
136}
137
138static void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
139{
140 debugfs_remove(otp->debugfs);
141}
142#else
143/* Compile this out if debugfs not selected */
144static inline int __init ab3100_otp_init_debugfs(struct device *dev,
145 struct ab3100_otp *otp)
146{
147 return 0;
148}
149
150static inline void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
151{
152}
153#endif
154
155#define SHOW_AB3100_ATTR(name) \
156static ssize_t ab3100_otp_##name##_show(struct device *dev, \
157 struct device_attribute *attr, \
158 char *buf) \
159{\
160 struct ab3100_otp *otp = dev_get_drvdata(dev); \
161 return sprintf(buf, "%u\n", otp->name); \
162}
163
164SHOW_AB3100_ATTR(locked)
165SHOW_AB3100_ATTR(freq)
166SHOW_AB3100_ATTR(paf)
167SHOW_AB3100_ATTR(imeich)
168SHOW_AB3100_ATTR(cid)
169SHOW_AB3100_ATTR(fac)
170SHOW_AB3100_ATTR(tac)
171SHOW_AB3100_ATTR(svn)
172
173static struct device_attribute ab3100_otp_attrs[] = {
174 __ATTR(locked, S_IRUGO, ab3100_otp_locked_show, NULL),
175 __ATTR(freq, S_IRUGO, ab3100_otp_freq_show, NULL),
176 __ATTR(paf, S_IRUGO, ab3100_otp_paf_show, NULL),
177 __ATTR(imeich, S_IRUGO, ab3100_otp_imeich_show, NULL),
178 __ATTR(cid, S_IRUGO, ab3100_otp_cid_show, NULL),
179 __ATTR(fac, S_IRUGO, ab3100_otp_fac_show, NULL),
180 __ATTR(tac, S_IRUGO, ab3100_otp_tac_show, NULL),
181 __ATTR(svn, S_IRUGO, ab3100_otp_svn_show, NULL),
182};
183
184static int __init ab3100_otp_probe(struct platform_device *pdev)
185{
186 struct ab3100_otp *otp;
187 int err = 0;
188 int i;
189
190 otp = devm_kzalloc(&pdev->dev, sizeof(struct ab3100_otp), GFP_KERNEL);
191 if (!otp)
192 return -ENOMEM;
193
194 otp->dev = &pdev->dev;
195
196 /* Replace platform data coming in with a local struct */
197 platform_set_drvdata(pdev, otp);
198
199 err = ab3100_otp_read(otp);
200 if (err)
201 return err;
202
203 dev_info(&pdev->dev, "AB3100 OTP readout registered\n");
204
205 /* sysfs entries */
206 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) {
207 err = device_create_file(&pdev->dev,
208 &ab3100_otp_attrs[i]);
209 if (err)
210 goto err;
211 }
212
213 /* debugfs entries */
214 err = ab3100_otp_init_debugfs(&pdev->dev, otp);
215 if (err)
216 goto err;
217
218 return 0;
219
220err:
221 while (--i >= 0)
222 device_remove_file(&pdev->dev, &ab3100_otp_attrs[i]);
223 return err;
224}
225
226static int __exit ab3100_otp_remove(struct platform_device *pdev)
227{
228 struct ab3100_otp *otp = platform_get_drvdata(pdev);
229 int i;
230
231 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
232 device_remove_file(&pdev->dev,
233 &ab3100_otp_attrs[i]);
234 ab3100_otp_exit_debugfs(otp);
235 return 0;
236}
237
238static struct platform_driver ab3100_otp_driver = {
239 .driver = {
240 .name = "ab3100-otp",
241 },
242 .remove = __exit_p(ab3100_otp_remove),
243};
244
245module_platform_driver_probe(ab3100_otp_driver, ab3100_otp_probe);
246
247MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
248MODULE_DESCRIPTION("AB3100 OTP Readout Driver");
249MODULE_LICENSE("GPL");
250