remarkable-linux/drivers/mtd/mtdchar.c
Kyungmin Park 493c646077 OneNAND: One-Time Programmable (OTP) support
One Block of the NAND Flash Array memory is reserved as
a One-Time Programmable Block memory area.
Also, 1st Block of NAND Flash Array can be used as OTP.

The OTP block can be read, programmed and locked using the same
operations as any other NAND Flash Array memory block.
OTP block cannot be erased.

OTP block is fully-guaranteed to be a valid block.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2006-05-12 15:35:50 +01:00

680 lines
14 KiB
C

/*
* $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $
*
* Character-device access to raw MTD devices.
*
*/
#include <linux/config.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/compatmac.h>
#include <asm/uaccess.h>
static struct class *mtd_class;
static void mtd_notify_add(struct mtd_info* mtd)
{
if (!mtd)
return;
class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
NULL, "mtd%d", mtd->index);
class_device_create(mtd_class, NULL,
MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
NULL, "mtd%dro", mtd->index);
}
static void mtd_notify_remove(struct mtd_info* mtd)
{
if (!mtd)
return;
class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
}
static struct mtd_notifier notifier = {
.add = mtd_notify_add,
.remove = mtd_notify_remove,
};
/*
* We use file->private_data to store a pointer to the MTDdevice.
* Since alighment is at least 32 bits, we have 2 bits free for OTP
* modes as well.
*/
#define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
#define MTD_MODE_OTP_FACT 1
#define MTD_MODE_OTP_USER 2
#define MTD_MODE(file) ((long)((file)->private_data) & 3)
#define SET_MTD_MODE(file, mode) \
do { long __p = (long)((file)->private_data); \
(file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
{
struct mtd_info *mtd = TO_MTD(file);
switch (orig) {
case 0:
/* SEEK_SET */
break;
case 1:
/* SEEK_CUR */
offset += file->f_pos;
break;
case 2:
/* SEEK_END */
offset += mtd->size;
break;
default:
return -EINVAL;
}
if (offset >= 0 && offset < mtd->size)
return file->f_pos = offset;
return -EINVAL;
}
static int mtd_open(struct inode *inode, struct file *file)
{
int minor = iminor(inode);
int devnum = minor >> 1;
struct mtd_info *mtd;
DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
if (devnum >= MAX_MTD_DEVICES)
return -ENODEV;
/* You can't open the RO devices RW */
if ((file->f_mode & 2) && (minor & 1))
return -EACCES;
mtd = get_mtd_device(NULL, devnum);
if (!mtd)
return -ENODEV;
if (MTD_ABSENT == mtd->type) {
put_mtd_device(mtd);
return -ENODEV;
}
file->private_data = mtd;
/* You can't open it RW if it's not a writeable device */
if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
put_mtd_device(mtd);
return -EACCES;
}
return 0;
} /* mtd_open */
/*====================================================================*/
static int mtd_close(struct inode *inode, struct file *file)
{
struct mtd_info *mtd;
DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
mtd = TO_MTD(file);
if (mtd->sync)
mtd->sync(mtd);
put_mtd_device(mtd);
return 0;
} /* mtd_close */
/* FIXME: This _really_ needs to die. In 2.5, we should lock the
userspace buffer down and use it directly with readv/writev.
*/
#define MAX_KMALLOC_SIZE 0x20000
static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
{
struct mtd_info *mtd = TO_MTD(file);
size_t retlen=0;
size_t total_retlen=0;
int ret=0;
int len;
char *kbuf;
DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
if (*ppos + count > mtd->size)
count = mtd->size - *ppos;
if (!count)
return 0;
/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
and pass them directly to the MTD functions */
if (count > MAX_KMALLOC_SIZE)
kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
else
kbuf=kmalloc(count, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
while (count) {
if (count > MAX_KMALLOC_SIZE)
len = MAX_KMALLOC_SIZE;
else
len = count;
switch (MTD_MODE(file)) {
case MTD_MODE_OTP_FACT:
ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
break;
case MTD_MODE_OTP_USER:
ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
break;
default:
ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
}
/* Nand returns -EBADMSG on ecc errors, but it returns
* the data. For our userspace tools it is important
* to dump areas with ecc errors !
* Userspace software which accesses NAND this way
* must be aware of the fact that it deals with NAND
*/
if (!ret || (ret == -EBADMSG)) {
*ppos += retlen;
if (copy_to_user(buf, kbuf, retlen)) {
kfree(kbuf);
return -EFAULT;
}
else
total_retlen += retlen;
count -= retlen;
buf += retlen;
if (retlen == 0)
count = 0;
}
else {
kfree(kbuf);
return ret;
}
}
kfree(kbuf);
return total_retlen;
} /* mtd_read */
static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
{
struct mtd_info *mtd = TO_MTD(file);
char *kbuf;
size_t retlen;
size_t total_retlen=0;
int ret=0;
int len;
DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
if (*ppos == mtd->size)
return -ENOSPC;
if (*ppos + count > mtd->size)
count = mtd->size - *ppos;
if (!count)
return 0;
if (count > MAX_KMALLOC_SIZE)
kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
else
kbuf=kmalloc(count, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
while (count) {
if (count > MAX_KMALLOC_SIZE)
len = MAX_KMALLOC_SIZE;
else
len = count;
if (copy_from_user(kbuf, buf, len)) {
kfree(kbuf);
return -EFAULT;
}
switch (MTD_MODE(file)) {
case MTD_MODE_OTP_FACT:
ret = -EROFS;
break;
case MTD_MODE_OTP_USER:
if (!mtd->write_user_prot_reg) {
ret = -EOPNOTSUPP;
break;
}
ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
break;
default:
ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
}
if (!ret) {
*ppos += retlen;
total_retlen += retlen;
count -= retlen;
buf += retlen;
}
else {
kfree(kbuf);
return ret;
}
}
kfree(kbuf);
return total_retlen;
} /* mtd_write */
/*======================================================================
IOCTL calls for getting device parameters.
======================================================================*/
static void mtdchar_erase_callback (struct erase_info *instr)
{
wake_up((wait_queue_head_t *)instr->priv);
}
static int mtd_ioctl(struct inode *inode, struct file *file,
u_int cmd, u_long arg)
{
struct mtd_info *mtd = TO_MTD(file);
void __user *argp = (void __user *)arg;
int ret = 0;
u_long size;
DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
if (cmd & IOC_IN) {
if (!access_ok(VERIFY_READ, argp, size))
return -EFAULT;
}
if (cmd & IOC_OUT) {
if (!access_ok(VERIFY_WRITE, argp, size))
return -EFAULT;
}
switch (cmd) {
case MEMGETREGIONCOUNT:
if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
return -EFAULT;
break;
case MEMGETREGIONINFO:
{
struct region_info_user ur;
if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
return -EFAULT;
if (ur.regionindex >= mtd->numeraseregions)
return -EINVAL;
if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
sizeof(struct mtd_erase_region_info)))
return -EFAULT;
break;
}
case MEMGETINFO:
if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
return -EFAULT;
break;
case MEMERASE:
{
struct erase_info *erase;
if(!(file->f_mode & 2))
return -EPERM;
erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
if (!erase)
ret = -ENOMEM;
else {
wait_queue_head_t waitq;
DECLARE_WAITQUEUE(wait, current);
init_waitqueue_head(&waitq);
memset (erase,0,sizeof(struct erase_info));
if (copy_from_user(&erase->addr, argp,
sizeof(struct erase_info_user))) {
kfree(erase);
return -EFAULT;
}
erase->mtd = mtd;
erase->callback = mtdchar_erase_callback;
erase->priv = (unsigned long)&waitq;
/*
FIXME: Allow INTERRUPTIBLE. Which means
not having the wait_queue head on the stack.
If the wq_head is on the stack, and we
leave because we got interrupted, then the
wq_head is no longer there when the
callback routine tries to wake us up.
*/
ret = mtd->erase(mtd, erase);
if (!ret) {
set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&waitq, &wait);
if (erase->state != MTD_ERASE_DONE &&
erase->state != MTD_ERASE_FAILED)
schedule();
remove_wait_queue(&waitq, &wait);
set_current_state(TASK_RUNNING);
ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
}
kfree(erase);
}
break;
}
case MEMWRITEOOB:
{
struct mtd_oob_buf buf;
void *databuf;
ssize_t retlen;
if(!(file->f_mode & 2))
return -EPERM;
if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
return -EFAULT;
if (buf.length > 0x4096)
return -EINVAL;
if (!mtd->write_oob)
ret = -EOPNOTSUPP;
else
ret = access_ok(VERIFY_READ, buf.ptr,
buf.length) ? 0 : EFAULT;
if (ret)
return ret;
databuf = kmalloc(buf.length, GFP_KERNEL);
if (!databuf)
return -ENOMEM;
if (copy_from_user(databuf, buf.ptr, buf.length)) {
kfree(databuf);
return -EFAULT;
}
ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
ret = -EFAULT;
kfree(databuf);
break;
}
case MEMREADOOB:
{
struct mtd_oob_buf buf;
void *databuf;
ssize_t retlen;
if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
return -EFAULT;
if (buf.length > 0x4096)
return -EINVAL;
if (!mtd->read_oob)
ret = -EOPNOTSUPP;
else
ret = access_ok(VERIFY_WRITE, buf.ptr,
buf.length) ? 0 : -EFAULT;
if (ret)
return ret;
databuf = kmalloc(buf.length, GFP_KERNEL);
if (!databuf)
return -ENOMEM;
ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
if (put_user(retlen, (uint32_t __user *)argp))
ret = -EFAULT;
else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
ret = -EFAULT;
kfree(databuf);
break;
}
case MEMLOCK:
{
struct erase_info_user info;
if (copy_from_user(&info, argp, sizeof(info)))
return -EFAULT;
if (!mtd->lock)
ret = -EOPNOTSUPP;
else
ret = mtd->lock(mtd, info.start, info.length);
break;
}
case MEMUNLOCK:
{
struct erase_info_user info;
if (copy_from_user(&info, argp, sizeof(info)))
return -EFAULT;
if (!mtd->unlock)
ret = -EOPNOTSUPP;
else
ret = mtd->unlock(mtd, info.start, info.length);
break;
}
case MEMSETOOBSEL:
{
if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
return -EFAULT;
break;
}
case MEMGETOOBSEL:
{
if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
return -EFAULT;
break;
}
case MEMGETBADBLOCK:
{
loff_t offs;
if (copy_from_user(&offs, argp, sizeof(loff_t)))
return -EFAULT;
if (!mtd->block_isbad)
ret = -EOPNOTSUPP;
else
return mtd->block_isbad(mtd, offs);
break;
}
case MEMSETBADBLOCK:
{
loff_t offs;
if (copy_from_user(&offs, argp, sizeof(loff_t)))
return -EFAULT;
if (!mtd->block_markbad)
ret = -EOPNOTSUPP;
else
return mtd->block_markbad(mtd, offs);
break;
}
#if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
case OTPSELECT:
{
int mode;
if (copy_from_user(&mode, argp, sizeof(int)))
return -EFAULT;
SET_MTD_MODE(file, 0);
switch (mode) {
case MTD_OTP_FACTORY:
if (!mtd->read_fact_prot_reg)
ret = -EOPNOTSUPP;
else
SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
break;
case MTD_OTP_USER:
if (!mtd->read_fact_prot_reg)
ret = -EOPNOTSUPP;
else
SET_MTD_MODE(file, MTD_MODE_OTP_USER);
break;
default:
ret = -EINVAL;
case MTD_OTP_OFF:
break;
}
file->f_pos = 0;
break;
}
case OTPGETREGIONCOUNT:
case OTPGETREGIONINFO:
{
struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
if (!buf)
return -ENOMEM;
ret = -EOPNOTSUPP;
switch (MTD_MODE(file)) {
case MTD_MODE_OTP_FACT:
if (mtd->get_fact_prot_info)
ret = mtd->get_fact_prot_info(mtd, buf, 4096);
break;
case MTD_MODE_OTP_USER:
if (mtd->get_user_prot_info)
ret = mtd->get_user_prot_info(mtd, buf, 4096);
break;
}
if (ret >= 0) {
if (cmd == OTPGETREGIONCOUNT) {
int nbr = ret / sizeof(struct otp_info);
ret = copy_to_user(argp, &nbr, sizeof(int));
} else
ret = copy_to_user(argp, buf, ret);
if (ret)
ret = -EFAULT;
}
kfree(buf);
break;
}
case OTPLOCK:
{
struct otp_info info;
if (MTD_MODE(file) != MTD_MODE_OTP_USER)
return -EINVAL;
if (copy_from_user(&info, argp, sizeof(info)))
return -EFAULT;
if (!mtd->lock_user_prot_reg)
return -EOPNOTSUPP;
ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
break;
}
#endif
default:
ret = -ENOTTY;
}
return ret;
} /* memory_ioctl */
static struct file_operations mtd_fops = {
.owner = THIS_MODULE,
.llseek = mtd_lseek,
.read = mtd_read,
.write = mtd_write,
.ioctl = mtd_ioctl,
.open = mtd_open,
.release = mtd_close,
};
static int __init init_mtdchar(void)
{
if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
MTD_CHAR_MAJOR);
return -EAGAIN;
}
mtd_class = class_create(THIS_MODULE, "mtd");
if (IS_ERR(mtd_class)) {
printk(KERN_ERR "Error creating mtd class.\n");
unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
return PTR_ERR(mtd_class);
}
register_mtd_user(&notifier);
return 0;
}
static void __exit cleanup_mtdchar(void)
{
unregister_mtd_user(&notifier);
class_destroy(mtd_class);
unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
}
module_init(init_mtdchar);
module_exit(cleanup_mtdchar);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Direct character-device access to MTD devices");