tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/init.h>
13#include <linux/platform_device.h>
14#include <linux/mfd/ab3100.h>
15#include <linux/debugfs.h>
16
17/* The OTP registers */
18#define AB3100_OTP0 0xb0
19#define AB3100_OTP1 0xb1
20#define AB3100_OTP2 0xb2
21#define AB3100_OTP3 0xb3
22#define AB3100_OTP4 0xb4
23#define AB3100_OTP5 0xb5
24#define AB3100_OTP6 0xb6
25#define AB3100_OTP7 0xb7
26#define AB3100_OTPP 0xbf
27
28/**
29 * struct ab3100_otp
30 * @dev containing device
31 * @ab3100 a pointer to the parent ab3100 device struct
32 * @locked whether the OTP is locked, after locking, no more bits
33 * can be changed but before locking it is still possible
34 * to change bits from 1->0.
35 * @freq clocking frequency for the OTP, this frequency is either
36 * 32768Hz or 1MHz/30
37 * @paf product activation flag, indicates whether this is a real
38 * product (paf true) or a lab board etc (paf false)
39 * @imeich if this is set it is possible to override the
40 * IMEI number found in the tac, fac and svn fields with
41 * (secured) software
42 * @cid customer ID
43 * @tac type allocation code of the IMEI
44 * @fac final assembly code of the IMEI
45 * @svn software version number of the IMEI
46 * @debugfs a debugfs file used when dumping to file
47 */
48struct ab3100_otp {
49 struct device *dev;
50 struct ab3100 *ab3100;
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 struct ab3100 *ab = otp->ab3100;
65 u8 otpval[8];
66 u8 otpp;
67 int err;
68
69 err = ab3100_get_register_interruptible(ab, AB3100_OTPP, &otpp);
70 if (err) {
71 dev_err(otp->dev, "unable to read OTPP register\n");
72 return err;
73 }
74
75 err = ab3100_get_register_page_interruptible(ab, AB3100_OTP0,
76 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_DEBUGFS
99static int show_otp(struct seq_file *s, void *v)
100{
101 struct ab3100_otp *otp = s->private;
102 int err;
103
104 seq_printf(s, "OTP is %s\n", otp->locked ? "LOCKED" : "UNLOCKED");
105 seq_printf(s, "OTP clock switch startup is %uHz\n", otp->freq);
106 seq_printf(s, "PAF is %s\n", otp->paf ? "SET" : "NOT SET");
107 seq_printf(s, "IMEI is %s\n", otp->imeich ?
108 "CHANGEABLE" : "NOT CHANGEABLE");
109 seq_printf(s, "CID: 0x%04x (decimal: %d)\n", otp->cid, otp->cid);
110 seq_printf(s, "IMEI: %u-%u-%u\n", otp->tac, otp->fac, otp->svn);
111 return 0;
112}
113
114static int ab3100_otp_open(struct inode *inode, struct file *file)
115{
116 return single_open(file, ab3100_otp_show, inode->i_private);
117}
118
119static const struct file_operations ab3100_otp_operations = {
120 .open = ab3100_otp_open,
121 .read = seq_read,
122 .llseek = seq_lseek,
123 .release = single_release,
124};
125
126static int __init ab3100_otp_init_debugfs(struct device *dev,
127 struct ab3100_otp *otp)
128{
129 otp->debugfs = debugfs_create_file("ab3100_otp", S_IFREG | S_IRUGO,
130 NULL, otp,
131 &ab3100_otp_operations);
132 if (!otp->debugfs) {
133 dev_err(dev, "AB3100 debugfs OTP file registration failed!\n");
134 return err;
135 }
136}
137
138static void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
139{
140 debugfs_remove_file(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 = kzalloc(sizeof(struct ab3100_otp), GFP_KERNEL);
191 if (!otp) {
192 dev_err(&pdev->dev, "could not allocate AB3100 OTP device\n");
193 return -ENOMEM;
194 }
195 otp->dev = &pdev->dev;
196
197 /* Replace platform data coming in with a local struct */
198 otp->ab3100 = platform_get_drvdata(pdev);
199 platform_set_drvdata(pdev, otp);
200
201 err = ab3100_otp_read(otp);
202 if (err)
203 return err;
204
205 dev_info(&pdev->dev, "AB3100 OTP readout registered\n");
206
207 /* sysfs entries */
208 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) {
209 err = device_create_file(&pdev->dev,
210 &ab3100_otp_attrs[i]);
211 if (err)
212 goto out_no_sysfs;
213 }
214
215 /* debugfs entries */
216 err = ab3100_otp_init_debugfs(&pdev->dev, otp);
217 if (err)
218 goto out_no_debugfs;
219
220 return 0;
221
222out_no_sysfs:
223 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
224 device_remove_file(&pdev->dev,
225 &ab3100_otp_attrs[i]);
226out_no_debugfs:
227 kfree(otp);
228 return err;
229}
230
231static int __exit ab3100_otp_remove(struct platform_device *pdev)
232{
233 struct ab3100_otp *otp = platform_get_drvdata(pdev);
234 int i;
235
236 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
237 device_remove_file(&pdev->dev,
238 &ab3100_otp_attrs[i]);
239 ab3100_otp_exit_debugfs(otp);
240 kfree(otp);
241 return 0;
242}
243
244static struct platform_driver ab3100_otp_driver = {
245 .driver = {
246 .name = "ab3100-otp",
247 .owner = THIS_MODULE,
248 },
249 .remove = __exit_p(ab3100_otp_remove),
250};
251
252static int __init ab3100_otp_init(void)
253{
254 return platform_driver_probe(&ab3100_otp_driver,
255 ab3100_otp_probe);
256}
257
258static void __exit ab3100_otp_exit(void)
259{
260 platform_driver_unregister(&ab3100_otp_driver);
261}
262
263module_init(ab3100_otp_init);
264module_exit(ab3100_otp_exit);
265
266MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
267MODULE_DESCRIPTION("AB3100 OTP Readout Driver");
268MODULE_LICENSE("GPL");