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 = 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 platform_set_drvdata(pdev, otp); 199 200 err = ab3100_otp_read(otp); 201 if (err) 202 goto err_otp_read; 203 204 dev_info(&pdev->dev, "AB3100 OTP readout registered\n"); 205 206 /* sysfs entries */ 207 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) { 208 err = device_create_file(&pdev->dev, 209 &ab3100_otp_attrs[i]); 210 if (err) 211 goto err_create_file; 212 } 213 214 /* debugfs entries */ 215 err = ab3100_otp_init_debugfs(&pdev->dev, otp); 216 if (err) 217 goto err_init_debugfs; 218 219 return 0; 220 221err_init_debugfs: 222err_create_file: 223 while (--i >= 0) 224 device_remove_file(&pdev->dev, &ab3100_otp_attrs[i]); 225err_otp_read: 226 kfree(otp); 227 return err; 228} 229 230static int __exit ab3100_otp_remove(struct platform_device *pdev) 231{ 232 struct ab3100_otp *otp = platform_get_drvdata(pdev); 233 int i; 234 235 for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) 236 device_remove_file(&pdev->dev, 237 &ab3100_otp_attrs[i]); 238 ab3100_otp_exit_debugfs(otp); 239 kfree(otp); 240 return 0; 241} 242 243static struct platform_driver ab3100_otp_driver = { 244 .driver = { 245 .name = "ab3100-otp", 246 .owner = THIS_MODULE, 247 }, 248 .remove = __exit_p(ab3100_otp_remove), 249}; 250 251static int __init ab3100_otp_init(void) 252{ 253 return platform_driver_probe(&ab3100_otp_driver, 254 ab3100_otp_probe); 255} 256 257static void __exit ab3100_otp_exit(void) 258{ 259 platform_driver_unregister(&ab3100_otp_driver); 260} 261 262module_init(ab3100_otp_init); 263module_exit(ab3100_otp_exit); 264 265MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); 266MODULE_DESCRIPTION("AB3100 OTP Readout Driver"); 267MODULE_LICENSE("GPL"); 268