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/init.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/mfd/ab3100.h>
  15 #include <linux/debugfs.h>
  16 #include <linux/seq_file.h>
  17
  18 /* The OTP registers */
  19 #define AB3100_OTP0             0xb0
  20 #define AB3100_OTP1             0xb1
  21 #define AB3100_OTP2             0xb2
  22 #define AB3100_OTP3             0xb3
  23 #define AB3100_OTP4             0xb4
  24 #define AB3100_OTP5             0xb5
  25 #define AB3100_OTP6             0xb6
  26 #define AB3100_OTP7             0xb7
  27 #define AB3100_OTPP             0xbf
  28
  29 /**
  30  * struct ab3100_otp
  31  * @dev containing device
  32  * @ab3100 a pointer to the parent ab3100 device struct
  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  */
  49 struct ab3100_otp {
  50         struct device *dev;
  51         struct ab3100 *ab3100;
  52         bool locked;
  53         u32 freq;
  54         bool paf;
  55         bool imeich;
  56         u16 cid:14;
  57         u32 tac:20;
  58         u8 fac;
  59         u32 svn:20;
  60         struct dentry *debugfs;
  61 };
  62
  63 static int __init ab3100_otp_read(struct ab3100_otp *otp)
  64 {
  65         struct ab3100 *ab = otp->ab3100;
  66         u8 otpval[8];
  67         u8 otpp;
  68         int err;
  69
  70         err = ab3100_get_register_interruptible(ab, AB3100_OTPP, &otpp);
  71         if (err) {
  72                 dev_err(otp->dev, "unable to read OTPP register\n");
  73                 return err;
  74         }
  75
  76         err = ab3100_get_register_page_interruptible(ab, AB3100_OTP0,
  77                                                      otpval, 8);
  78         if (err) {
  79                 dev_err(otp->dev, "unable to read OTP register page\n");
  80                 return err;
  81         }
  82
  83         /* Cache OTP properties, they never change by nature */
  84         otp->locked = (otpp & 0x80);
  85         otp->freq = (otpp & 0x40) ? 32768 : 34100;
  86         otp->paf = (otpval[1] & 0x80);
  87         otp->imeich = (otpval[1] & 0x40);
  88         otp->cid = ((otpval[1] << 8) | otpval[0]) & 0x3fff;
  89         otp->tac = ((otpval[4] & 0x0f) << 16) | (otpval[3] << 8) | otpval[2];
  90         otp->fac = ((otpval[5] & 0x0f) << 4) | (otpval[4] >> 4);
  91         otp->svn = (otpval[7] << 12) | (otpval[6] << 4) | (otpval[5] >> 4);
  92         return 0;
  93 }
  94
  95 /*
  96  * This is a simple debugfs human-readable file that dumps out
  97  * the contents of the OTP.
  98  */
  99 #ifdef CONFIG_DEBUG_FS
 100 static int ab3100_show_otp(struct seq_file *s, void *v)
 101 {
 102         struct ab3100_otp *otp = s->private;
 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
 114 static int ab3100_otp_open(struct inode *inode, struct file *file)
 115 {
 116         return single_open(file, ab3100_show_otp, inode->i_private);
 117 }
 118
 119 static 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
 126 static 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 -ENOENT;
 135         }
 136         return 0;
 137 }
 138
 139 static void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
 140 {
 141         debugfs_remove(otp->debugfs);
 142 }
 143 #else
 144 /* Compile this out if debugfs not selected */
 145 static inline int __init ab3100_otp_init_debugfs(struct device *dev,
 146                                                  struct ab3100_otp *otp)
 147 {
 148         return 0;
 149 }
 150
 151 static inline void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp)
 152 {
 153 }
 154 #endif
 155
 156 #define SHOW_AB3100_ATTR(name) \
 157 static ssize_t ab3100_otp_##name##_show(struct device *dev, \
 158                                struct device_attribute *attr, \
 159                                char *buf) \
 160 {\
 161         struct ab3100_otp *otp = dev_get_drvdata(dev); \
 162         return sprintf(buf, "%u\n", otp->name); \
 163 }
 164
 165 SHOW_AB3100_ATTR(locked)
 166 SHOW_AB3100_ATTR(freq)
 167 SHOW_AB3100_ATTR(paf)
 168 SHOW_AB3100_ATTR(imeich)
 169 SHOW_AB3100_ATTR(cid)
 170 SHOW_AB3100_ATTR(fac)
 171 SHOW_AB3100_ATTR(tac)
 172 SHOW_AB3100_ATTR(svn)
 173
 174 static struct device_attribute ab3100_otp_attrs[] = {
 175         __ATTR(locked, S_IRUGO, ab3100_otp_locked_show, NULL),
 176         __ATTR(freq, S_IRUGO, ab3100_otp_freq_show, NULL),
 177         __ATTR(paf, S_IRUGO, ab3100_otp_paf_show, NULL),
 178         __ATTR(imeich, S_IRUGO, ab3100_otp_imeich_show, NULL),
 179         __ATTR(cid, S_IRUGO, ab3100_otp_cid_show, NULL),
 180         __ATTR(fac, S_IRUGO, ab3100_otp_fac_show, NULL),
 181         __ATTR(tac, S_IRUGO, ab3100_otp_tac_show, NULL),
 182         __ATTR(svn, S_IRUGO, ab3100_otp_svn_show, NULL),
 183 };
 184
 185 static int __init ab3100_otp_probe(struct platform_device *pdev)
 186 {
 187         struct ab3100_otp *otp;
 188         int err = 0;
 189         int i;
 190
 191         otp = kzalloc(sizeof(struct ab3100_otp), GFP_KERNEL);
 192         if (!otp) {
 193                 dev_err(&pdev->dev, "could not allocate AB3100 OTP device\n");
 194                 return -ENOMEM;
 195         }
 196         otp->dev = &pdev->dev;
 197
 198         /* Replace platform data coming in with a local struct */
 199         otp->ab3100 = platform_get_drvdata(pdev);
 200         platform_set_drvdata(pdev, otp);
 201
 202         err = ab3100_otp_read(otp);
 203         if (err)
 204                 return err;
 205
 206         dev_info(&pdev->dev, "AB3100 OTP readout registered\n");
 207
 208         /* sysfs entries */
 209         for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) {
 210                 err = device_create_file(&pdev->dev,
 211                                          &ab3100_otp_attrs[i]);
 212                 if (err)
 213                         goto out_no_sysfs;
 214         }
 215
 216         /* debugfs entries */
 217         err = ab3100_otp_init_debugfs(&pdev->dev, otp);
 218         if (err)
 219                 goto out_no_debugfs;
 220
 221         return 0;
 222
 223 out_no_sysfs:
 224         for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
 225                 device_remove_file(&pdev->dev,
 226                                    &ab3100_otp_attrs[i]);
 227 out_no_debugfs:
 228         kfree(otp);
 229         return err;
 230 }
 231
 232 static int __exit ab3100_otp_remove(struct platform_device *pdev)
 233 {
 234         struct ab3100_otp *otp = platform_get_drvdata(pdev);
 235         int i;
 236
 237         for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++)
 238                 device_remove_file(&pdev->dev,
 239                                    &ab3100_otp_attrs[i]);
 240         ab3100_otp_exit_debugfs(otp);
 241         kfree(otp);
 242         return 0;
 243 }
 244
 245 static struct platform_driver ab3100_otp_driver = {
 246         .driver = {
 247                 .name = "ab3100-otp",
 248                 .owner = THIS_MODULE,
 249         },
 250         .remove  = __exit_p(ab3100_otp_remove),
 251 };
 252
 253 static int __init ab3100_otp_init(void)
 254 {
 255         return platform_driver_probe(&ab3100_otp_driver,
 256                                      ab3100_otp_probe);
 257 }
 258
 259 static void __exit ab3100_otp_exit(void)
 260 {
 261         platform_driver_unregister(&ab3100_otp_driver);
 262 }
 263
 264 module_init(ab3100_otp_init);
 265 module_exit(ab3100_otp_exit);
 266
 267 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
 268 MODULE_DESCRIPTION("AB3100 OTP Readout Driver");
 269 MODULE_LICENSE("GPL");