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");