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