diff options
Diffstat (limited to 'drivers/mfd/ab3100-otp.c')
| -rw-r--r-- | drivers/mfd/ab3100-otp.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/mfd/ab3100-otp.c b/drivers/mfd/ab3100-otp.c new file mode 100644 index 000000000..c393102e3 --- /dev/null +++ b/drivers/mfd/ab3100-otp.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/mfd/ab3100_otp.c + * + * Copyright (C) 2007-2009 ST-Ericsson AB + * 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; +} + +/* + * This is a simple debugfs human-readable file that dumps out + * the contents of the OTP. + */ +#ifdef CONFIG_DEBUG_FS +static int ab3100_show_otp(struct seq_file *s, void *v) +{ + struct ab3100_otp *otp = s->private; + + seq_printf(s, "OTP is %s\n", otp->locked ? "LOCKED" : "UNLOCKED"); + seq_printf(s, "OTP clock switch startup is %uHz\n", otp->freq); + seq_printf(s, "PAF is %s\n", otp->paf ? "SET" : "NOT SET"); + seq_printf(s, "IMEI is %s\n", otp->imeich ? + "CHANGEABLE" : "NOT CHANGEABLE"); + seq_printf(s, "CID: 0x%04x (decimal: %d)\n", otp->cid, otp->cid); + seq_printf(s, "IMEI: %u-%u-%u\n", otp->tac, otp->fac, otp->svn); + return 0; +} + +static int ab3100_otp_open(struct inode *inode, struct file *file) +{ + return single_open(file, ab3100_show_otp, inode->i_private); +} + +static const struct file_operations ab3100_otp_operations = { + .open = ab3100_otp_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void __init ab3100_otp_init_debugfs(struct device *dev, + struct ab3100_otp *otp) +{ + otp->debugfs = debugfs_create_file("ab3100_otp", S_IFREG | S_IRUGO, + NULL, otp, &ab3100_otp_operations); +} + +static void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp) +{ + debugfs_remove(otp->debugfs); +} +#else +/* Compile this out if debugfs not selected */ +static inline void __init ab3100_otp_init_debugfs(struct device *dev, + struct ab3100_otp *otp) +{ +} + +static inline void __exit ab3100_otp_exit_debugfs(struct ab3100_otp *otp) +{ +} +#endif + +#define SHOW_AB3100_ATTR(name) \ +static ssize_t ab3100_otp_##name##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ +{\ + struct ab3100_otp *otp = dev_get_drvdata(dev); \ + return sprintf(buf, "%u\n", otp->name); \ +} + +SHOW_AB3100_ATTR(locked) +SHOW_AB3100_ATTR(freq) +SHOW_AB3100_ATTR(paf) +SHOW_AB3100_ATTR(imeich) +SHOW_AB3100_ATTR(cid) +SHOW_AB3100_ATTR(fac) +SHOW_AB3100_ATTR(tac) +SHOW_AB3100_ATTR(svn) + +static struct device_attribute ab3100_otp_attrs[] = { + __ATTR(locked, S_IRUGO, ab3100_otp_locked_show, NULL), + __ATTR(freq, S_IRUGO, ab3100_otp_freq_show, NULL), + __ATTR(paf, S_IRUGO, ab3100_otp_paf_show, NULL), + __ATTR(imeich, S_IRUGO, ab3100_otp_imeich_show, NULL), + __ATTR(cid, S_IRUGO, ab3100_otp_cid_show, NULL), + __ATTR(fac, S_IRUGO, ab3100_otp_fac_show, NULL), + __ATTR(tac, S_IRUGO, ab3100_otp_tac_show, NULL), + __ATTR(svn, S_IRUGO, ab3100_otp_svn_show, NULL), +}; + +static int __init ab3100_otp_probe(struct platform_device *pdev) +{ + struct ab3100_otp *otp; + int err = 0; + int i; + + otp = devm_kzalloc(&pdev->dev, sizeof(struct ab3100_otp), GFP_KERNEL); + if (!otp) + return -ENOMEM; + + otp->dev = &pdev->dev; + + /* Replace platform data coming in with a local struct */ + platform_set_drvdata(pdev, otp); + + err = ab3100_otp_read(otp); + if (err) + return err; + + dev_info(&pdev->dev, "AB3100 OTP readout registered\n"); + + /* sysfs entries */ + for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) { + err = device_create_file(&pdev->dev, + &ab3100_otp_attrs[i]); + if (err) + goto err; + } + + /* debugfs entries */ + ab3100_otp_init_debugfs(&pdev->dev, otp); + + return 0; + +err: + while (--i >= 0) + device_remove_file(&pdev->dev, &ab3100_otp_attrs[i]); + return err; +} + +static int __exit ab3100_otp_remove(struct platform_device *pdev) +{ + struct ab3100_otp *otp = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < ARRAY_SIZE(ab3100_otp_attrs); i++) + device_remove_file(&pdev->dev, + &ab3100_otp_attrs[i]); + ab3100_otp_exit_debugfs(otp); + return 0; +} + +static struct platform_driver ab3100_otp_driver = { + .driver = { + .name = "ab3100-otp", + }, + .remove = __exit_p(ab3100_otp_remove), +}; + +module_platform_driver_probe(ab3100_otp_driver, ab3100_otp_probe); + +MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); +MODULE_DESCRIPTION("AB3100 OTP Readout Driver"); +MODULE_LICENSE("GPL"); |