linux-imx

/*

 * drivers/mfd/ab3100_otp.c

 *

 * Copyright (C) 2007-2009 ST-Ericsson AB

 * License terms: GNU General Public License (GPL) version 2

 * Driver to read out OTP from the AB3100 Mixed-signal circuit

 * Author: Linus Walleij <linus.walleij@stericsson.com>

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/platform_device.h>

#include <linux/mfd/abx500.h>

#include <linux/debugfs.h>

#include <linux/seq_file.h>

​

/* The OTP registers */

#define AB3100_OTP0     0xb0

#define AB3100_OTP1     0xb1

#define AB3100_OTP2     0xb2

#define AB3100_OTP3     0xb3

#define AB3100_OTP4     0xb4

#define AB3100_OTP5     0xb5

#define AB3100_OTP6     0xb6

#define AB3100_OTP7     0xb7

#define AB3100_OTPP     0xbf

​

/**

 * struct ab3100_otp

 * @dev containing device

 * @locked whether the OTP is locked, after locking, no more bits

 *       can be changed but before locking it is still possible

 *       to change bits from 1->0.

 * @freq clocking frequency for the OTP, this frequency is either

 *       32768Hz or 1MHz/30

 * @paf product activation flag, indicates whether this is a real

 *       product (paf true) or a lab board etc (paf false)

 * @imeich if this is set it is possible to override the

 *       IMEI number found in the tac, fac and svn fields with

 *       (secured) software

 * @cid customer ID

 * @tac type allocation code of the IMEI

 * @fac final assembly code of the IMEI

 * @svn software version number of the IMEI

 * @debugfs a debugfs file used when dumping to file

 */

struct ab3100_otp {

    struct device *dev;

    bool locked;

    u32 freq;

    bool paf;

    bool imeich;

    u16 cid:14;

    u32 tac:20;

    u8 fac;

    u32 svn:20;

    struct dentry *debugfs;

};

​

static int __init ab3100_otp_read(struct ab3100_otp *otp)

{

    u8 otpval[8];

    u8 otpp;

    int err;

​

    err = abx500_get_register_interruptible(otp->dev, 0,

        AB3100_OTPP, &otpp);

    if (err) {

        dev_err(otp->dev, "unable to read OTPP register\n");

        return err;

    }

​

    err = abx500_get_register_page_interruptible(otp->dev, 0,

        AB3100_OTP0, otpval, 8);

    if (err) {

        dev_err(otp->dev, "unable to read OTP register page\n");

        return err;

    }

​

    /* Cache OTP properties, they never change by nature */

    otp->locked = (otpp & 0x80);

    otp->freq = (otpp & 0x40) ? 32768 : 34100;

    otp->paf = (otpval[1] & 0x80);

    otp->imeich = (otpval[1] & 0x40);

    otp->cid = ((otpval[1] << 8) | otpval[0]) & 0x3fff;

    otp->tac = ((otpval[4] & 0x0f) << 16) | (otpval[3] << 8) | otpval[2];

    otp->fac = ((otpval[5] & 0x0f) << 4) | (otpval[4] >> 4);

    otp->svn = (otpval[7] << 12) | (otpval[6] << 4) | (otpval[5] >> 4);

    return 0;

}