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/*
* Copyright (C) 2014 Spreadtrum Communications Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/bug.h>
#include <linux/debugfs.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include "sprd_otp.h"
/* cached otp blocks max 32X32 */
#define CACHED_BLOCK_MAX ( 32 )
#define CACHED_BLOCK_WIDTH ( 32 ) /* bit counts */
static u8 cached_otp[CACHED_BLOCK_MAX * CACHED_BLOCK_WIDTH / 8];
/*
* Head entry for the doubly linked sprd otp list
*/
static LIST_HEAD(sprd_otp_list);
static DEFINE_MUTEX(sprd_otp_mtx);
static struct sprd_otp_device *__sprd_otp_find(int minor)
{
struct sprd_otp_device *otp;
if (unlikely(list_empty(&sprd_otp_list)))
return NULL;
list_for_each_entry(otp, &sprd_otp_list, list) {
if (otp->misc.minor == minor) {
return otp;
}
}
return NULL;
}
static ssize_t sprd_otp_read(struct file *file, char __user * buf,
size_t count, loff_t * f_pos)
{
int ret;
int minor = iminor(file_inode(file));
struct sprd_otp_device *otp = __sprd_otp_find(minor);
mutex_lock(&sprd_otp_mtx);
if (otp && otp->ops && otp->ops->read) {
int i, blk_index = (int)*f_pos / otp->blk_width;
int blk_max = blk_index + DIV_ROUND_UP(count, otp->blk_width);
pr_debug("otp read blk %d - %d\n", blk_index, blk_max);
if (blk_max > otp->blk_max)
blk_max = otp->blk_max;
for (i = blk_index; i < blk_max; i++) {
int index = i * otp->blk_width;
u32 val = otp->ops->read(i);
memcpy(&cached_otp[index], &val, otp->blk_width);
}
}
pr_debug("otp read from %d %u %d\n", (int)*f_pos, count,
(int)file->f_pos);
ret =
simple_read_from_buffer(buf, count, f_pos, cached_otp,
sizeof(cached_otp));
mutex_unlock(&sprd_otp_mtx);
return ret;
}
static ssize_t sprd_otp_write(struct file *file, const char __user * buf,
size_t count, loff_t * f_pos)
{
ssize_t ret;
int pos = (int)*f_pos;
int minor = iminor(file_inode(file));
struct sprd_otp_device *otp = __sprd_otp_find(minor);
pr_debug("otp write to %d %u %d\n", (int)*f_pos, count,
(int)file->f_pos);
mutex_lock(&sprd_otp_mtx);
ret = simple_write_to_buffer(cached_otp, sizeof(cached_otp), f_pos,
buf, count);
if (IS_ERR_VALUE(ret))
goto out;
if (otp && otp->ops && otp->ops->prog) {
int blk_index = pos / otp->blk_width;
pr_debug("otp prog blk %d\n", blk_index);
BUG_ON(count != otp->blk_width);
if (blk_index < otp->blk_max) {
int index = blk_index * otp->blk_width;
u32 val = 0;
memcpy(&val, &cached_otp[index], otp->blk_width);
otp->ops->prog(blk_index, val);
}
}
out:
mutex_unlock(&sprd_otp_mtx);
return ret;
}
static loff_t sprd_otp_llseek(struct file *file, loff_t offset, int whence)
{
pr_debug("otp seek at %d %d\n", (int)offset, whence);
switch (whence) {
case SEEK_SET:
file->f_pos = offset;
break;
case SEEK_CUR:
file->f_pos += offset;
break;
default:
return -EINVAL;
}
return file->f_pos;
}
static const struct file_operations sprd_otp_fops = {
.owner = THIS_MODULE,
.read = sprd_otp_read,
.write = sprd_otp_write,
.llseek = sprd_otp_llseek,
};
static struct miscdevice dummy_otp = {
.minor = MISC_DYNAMIC_MINOR,
.name = "sprd_dummy_otp",
.fops = &sprd_otp_fops,
};
void *sprd_otp_register(const char *name, void *ops, int blk_max, int blk_width)
{
int ret;
struct sprd_otp_device *otp;
otp = kzalloc(sizeof(struct sprd_otp_device), GFP_KERNEL);
if (unlikely(!otp))
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&otp->list);
otp->misc.minor = MISC_DYNAMIC_MINOR;
otp->misc.name = kstrdup(name, GFP_KERNEL);
otp->misc.fops = &sprd_otp_fops;
otp->blk_max = blk_max;
otp->blk_width = blk_width; /*MUST be bytes count */
BUG_ON(otp->blk_width > sizeof(u32));
BUG_ON(otp->blk_max * otp->blk_width > sizeof(cached_otp));
otp->ops = ops;
ret = misc_register(&otp->misc);
if (ret)
return ERR_PTR(ret);
mutex_lock(&sprd_otp_mtx);
list_add(&otp->list, &sprd_otp_list);
mutex_unlock(&sprd_otp_mtx);
pr_info("otp register %s as miscdevice %d, block %uX%ubits\n",
otp->misc.name, otp->misc.minor, otp->blk_max,
otp->blk_width * 8);
return otp->misc.this_device;
}
static ssize_t otp_info_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "cached otp blocks: %uX%ubits\n",
CACHED_BLOCK_MAX, CACHED_BLOCK_WIDTH);
}
static DEVICE_ATTR(info, S_IRUGO, otp_info_show, NULL);
static int __init sprd_otp_init(void)
{
int ret;
ret = misc_register(&dummy_otp);
if (ret)
return ret;
ret = device_create_file(dummy_otp.this_device, &dev_attr_info);
if (ret)
return ret;
#if defined(CONFIG_OTP_SPRD_EFUSE)
sprd_efuse_init();
#endif
#if defined(CONFIG_OTP_SPRD_ADIE_EFUSE)
sprd_adie_efuse_init();
#endif
#if defined(CONFIG_OTP_SPRD_LASER_FUSE)
sprd_adie_laserfuse_init();
#endif
return ret;
}
static void __exit sprd_otp_exit(void)
{
misc_deregister(&dummy_otp);
}
module_init(sprd_otp_init);
module_exit(sprd_otp_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Spreadtrum OTP Efuse Driver");
MODULE_AUTHOR("robot <zhulin.lian@spreadtrum.com>");
MODULE_VERSION("0.1");
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