drivers/mfd/ab3100-otp.c

   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/ab3100.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  * @ab3100 a pointer to the parent ab3100 device struct
  34  * @locked whether the OTP is locked, after locking, no more bits
  35  *       can be changed but before locking it is still possible
  36  *       to change bits from 1->0.
  37  * @freq clocking frequency for the OTP, this frequency is either
  38  *       32768Hz or 1MHz/30
  39  * @paf product activation flag, indicates whether this is a real
  40  *       product (paf true) or a lab board etc (paf false)
  41  * @imeich if this is set it is possible to override the
  42  *       IMEI number found in the tac, fac and svn fields with
  43  *       (secured) software
  44  * @cid customer ID
  45  * @tac type allocation code of the IMEI
  46  * @fac final assembly code of the IMEI
  47  * @svn software version number of the IMEI
  48  * @debugfs a debugfs file used when dumping to file
  49  */
  50 struct ab3100_otp {
  51         struct device *dev;
  52         struct ab3100 *ab3100;
  53         bool locked;
  54         u32 freq;
  55         bool paf;
  56         bool imeich;
  57         u16 cid:14;
  58         u32 tac:20;
  59         u8 fac;
  60         u32 svn:20;
  61         struct dentry *debugfs;
  62 };
  63
  64 static int __init ab3100_otp_read(struct ab3100_otp *otp)
  65 {
  66         struct ab3100 *ab = otp->ab3100;
  67         u8 otpval[8];
  68         u8 otpp;
  69         int err;
  70
  71         err = ab3100_get_register_interruptible(ab, AB3100_OTPP, &otpp);
  72         if (err) {
  73                 dev_err(otp->dev, "unable to read OTPP register\n");
  74                 return err;
  75         }
  76
  77         err = ab3100_get_register_page_interruptible(ab, AB3100_OTP0,
  78                                                      otpval, 8);
  79         if (err) {
  80                 dev_err(otp->dev, "unable to read OTP register page\n");
  81                 return err;
  82         }
  83
  84         /* Cache OTP properties, they never change by nature */
  85         otp->locked = (otpp & 0x80);
  86         otp->freq = (otpp & 0x40) ? 32768 : 34100;
  87         otp->paf = (otpval[1] & 0x80);
  88         otp->imeich = (otpval[1] & 0x40);
  89         otp->cid = ((otpval[1] << 8) | otpval[0]) & 0x3fff;
  90         otp->tac = ((otpval[4] & 0x0f) << 16) | (otpval[3] << 8) | otpval[2];
  91         otp->fac = ((otpval[5] & 0x0f) << 4) | (otpval[4] >> 4);
  92         otp->svn = (otpval[7] << 12) | (otpval[6] << 4) | (otpval[5] >> 4);
  93         return 0;
  94 }
  95
  96 /*
  97  * This is a simple debugfs human-readable file that dumps out
  98  * the contents of the OTP.
  99  */
 100 #ifdef CONFIG_DEBUG_FS
 101 static int ab3100_show_otp(struct seq_file *s, void *v)
 102 {
 103         struct ab3100_otp *otp = s->private;
 104
 105         seq_printf(s, "OTP is %s\n", otp->locked ? "LOCKED" : "UNLOCKED");
 106         seq_printf(s, "OTP clock switch startup is %uHz\n", otp->freq);
 107         seq_printf(s, "PAF is %s\n", otp->paf ? "SET" : "NOT SET");
 108         seq_printf(s, "IMEI is %s\n", otp->imeich ?
 109                    "CHANGEABLE" : "NOT CHANGEABLE");
 110         seq_printf(s, "CID: 0x%04x (decimal: %d)\n", otp->cid, otp->cid);
 111         seq_printf(s, "IMEI: %u-%u-%u\n", otp->tac, otp->fac, otp->svn);
 112         return 0;
 113 }
 114
 115 static int ab3100_otp_open(struct inode *inode, struct file *file)
 116 {
 117         return single_open(file, ab3100_show_otp, inode->i_private);
 118 }
 119
 120 static const struct file_operations ab3100_otp_operations = {
 121         .open           = ab3100_otp_open,
 122         .read           = seq_read,
 123         .llseek         = seq_lseek,
 124         .release        = single_release,
 125 };
 126
 127 static int __init ab3100_otp_init_debugfs(struct device *dev,
 128                                           struct ab3100_otp *otp)
 129 {
 130         otp->debugfs = debugfs_create_file("ab3100_otp", S_IFREG | S_IRUGO,
 131                                            NULL, otp,
 132                                            &ab3100_otp_operations);
 133         if (!otp->debugfs) {
 134                 dev_err(dev, "AB3100 debugfs OTP file registration failed!\n");
 135                 return -ENOENT;
 136         }
 137         return 0;
 138 }
 139
 140 static void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
 141 {
 142         debugfs_remove(otp->debugfs);
 143 }
 144 #else
 145 /* Compile this out if debugfs not selected */
 146 static inline int __init ab3100_otp_init_debugfs(struct device *dev,
 147                                                  struct ab3100_otp *otp)
 148 {
 149         return 0;
 150 }
 151
 152 static inline void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
 153 {
 154 }
 155 #endif
 156
 157 #define SHOW_AB3100_ATTR(name) \
 158 static ssize_t ab3100_otp_##name##_show(struct device *dev, \
 159                                struct device_attribute *attr, \
 160                                char *buf) \
 161 {\
 162         struct ab3100_otp *otp = dev_get_drvdata(dev); \
 163         return sprintf(buf, "%u\n", otp->name); \
 164 }
 165
 166 SHOW_AB3100_ATTR(locked)
 167 SHOW_AB3100_ATTR(freq)
 168 SHOW_AB3100_ATTR(paf)
 169 SHOW_AB3100_ATTR(imeich)
 170 SHOW_AB3100_ATTR(cid)
 171 SHOW_AB3100_ATTR(fac)
 172 SHOW_AB3100_ATTR(tac)
 173 SHOW_AB3100_ATTR(svn)
 174
 175 static struct device_attribute ab3100_otp_attrs[] = {
 176         __ATTR(locked, S_IRUGO, ab3100_otp_locked_show, NULL),
 177         __ATTR(freq, S_IRUGO, ab3100_otp_freq_show, NULL),
 178         __ATTR(paf, S_IRUGO, ab3100_otp_paf_show, NULL),
 179         __ATTR(imeich, S_IRUGO, ab3100_otp_imeich_show, NULL),
 180         __ATTR(cid, S_IRUGO, ab3100_otp_cid_show, NULL),
 181         __ATTR(fac, S_IRUGO, ab3100_otp_fac_show, NULL),
 182         __ATTR(tac, S_IRUGO, ab3100_otp_tac_show, NULL),
 183         __ATTR(svn, S_IRUGO, ab3100_otp_svn_show, NULL),
 184 };
 185
 186 static int __init ab3100_otp_probe(struct platform_device *pdev)
 187 {
 188         struct ab3100_otp *otp;
 189         int err = 0;
 190         int i;
 191
 192         otp = kzalloc(sizeof(struct ab3100_otp), GFP_KERNEL);
 193         if (!otp) {
 194                 dev_err(&pdev->dev, "could not allocate AB3100 OTP device\n");
 195                 return -ENOMEM;
 196         }
 197         otp->dev = &pdev->dev;
 198
 199         /* Replace platform data coming in with a local struct */
 200         otp->ab3100 = platform_get_drvdata(pdev);
 201         platform_set_drvdata(pdev, otp);
 202
 203         err = ab3100_otp_read(otp);
 204         if (err)
 205                 return err;
 206
 207         dev_info(&pdev->dev, "AB3100 OTP readout registered\n");
 208
 209         /* sysfs entries */
 210         for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) {
 211                 err = device_create_file(&pdev->dev,
 212                                          &ab3100_otp_attrs[i]);
 213                 if (err)
 214                         goto out_no_sysfs;
 215         }
 216
 217         /* debugfs entries */
 218         err = ab3100_otp_init_debugfs(&pdev->dev, otp);
 219         if (err)
 220                 goto out_no_debugfs;
 221
 222         return 0;
 223
 224 out_no_sysfs:
 225         for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
 226                 device_remove_file(&pdev->dev,
 227                                    &ab3100_otp_attrs[i]);
 228 out_no_debugfs:
 229         kfree(otp);
 230         return err;
 231 }
 232
 233 static int __exit ab3100_otp_remove(struct platform_device *pdev)
 234 {
 235         struct ab3100_otp *otp = platform_get_drvdata(pdev);
 236         int i;
 237
 238         for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
 239                 device_remove_file(&pdev->dev,
 240                                    &ab3100_otp_attrs[i]);
 241         ab3100_otp_exit_debugfs(otp);
 242         kfree(otp);
 243         return 0;
 244 }
 245
 246 static struct platform_driver ab3100_otp_driver = {
 247         .driver = {
 248                 .name = "ab3100-otp",
 249                 .owner = THIS_MODULE,
 250         },
 251         .remove  = __exit_p(ab3100_otp_remove),
 252 };
 253
 254 static int __init ab3100_otp_init(void)
 255 {
 256         return platform_driver_probe(&ab3100_otp_driver,
 257                                      ab3100_otp_probe);
 258 }
 259
 260 static void __exit ab3100_otp_exit(void)
 261 {
 262         platform_driver_unregister(&ab3100_otp_driver);
 263 }
 264
 265 module_init(ab3100_otp_init);
 266 module_exit(ab3100_otp_exit);
 267
 268 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
 269 MODULE_DESCRIPTION("AB3100 OTP Readout Driver");
 270 MODULE_LICENSE("GPL");