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/*======================================================================
$Id: doc1000.c,v 1.15 2001/10/02 15:05:13 dwmw2 Exp $
======================================================================*/
#include <linux/config.h>
#include <linux/module.h>
#include <asm/uaccess.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/segment.h>
#include <stdarg.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/iflash.h>
/* Parameters that can be set with 'insmod' */
static u_long base = 0xe0000;
static int erase_timeout = 10*HZ; /* in ticks */
static int retry_limit = 4; /* write retries */
static u_long max_tries = 4096; /* status polling */
MODULE_PARM(base,"l");
MODULE_PARM(erase_timeout, "i");
MODULE_PARM(retry_limit, "i");
MODULE_PARM(max_tries, "i");
#define WINDOW_SIZE 0x2000
#define WINDOW_MASK (WINDOW_SIZE - 1)
#define PAGEREG_LO (WINDOW_SIZE)
#define PAGEREG_HI (WINDOW_SIZE + 2)
static struct mtd_info *mymtd;
static struct timer_list flashcard_timer;
#define MAX_CELLS 32
#define MAX_FLASH_DEVICES 8
/* A flash region is composed of one or more "cells", where we allow
simultaneous erases if they are in different cells */
struct mypriv {
u_char *baseaddr;
u_short curpage;
u_char locked;
u_short numdevices;
u_char interleave;
struct erase_info *cur_erases;
wait_queue_head_t wq;
u_char devstat[MAX_FLASH_DEVICES];
u_long devshift;
};
static void flashcard_periodic(u_long data);
static int flashcard_erase (struct mtd_info *mtd, struct erase_info *instr);
static int flashcard_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
static int flashcard_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
static void flashcard_sync (struct mtd_info *mtd);
static inline void resume_erase(volatile u_char *addr);
static inline int suspend_erase(volatile u_char *addr);
static inline int byte_write (volatile u_char *addr, u_char byte);
static inline int word_write (volatile u_char *addr, __u16 word);
static inline int check_write(volatile u_char *addr);
static inline void block_erase (volatile u_char *addr);
static inline int check_erase(volatile u_char *addr);
#ifdef CONFIG_SMP
#warning This is definitely not SMP safe. Lock the paging mechanism.
#endif
static u_char *pagein(struct mtd_info *mtd, u_long addr)
{
struct mypriv *priv=mtd->priv;
u_short page = addr >> 13;
priv->baseaddr[PAGEREG_LO] = page & 0xff;
priv->baseaddr[PAGEREG_HI] = page >> 8;
priv->curpage = page;
return &priv->baseaddr[addr & WINDOW_MASK];
}
void flashcard_sync (struct mtd_info *mtd)
{
struct mypriv *priv=mtd->priv;
flashcard_periodic((u_long) mtd);
printk("sync...");
if (priv->cur_erases)
interruptible_sleep_on(&priv->wq);
printk("Done.\n");
}
int flashcard_erase (struct mtd_info *mtd, struct erase_info *instr)
{
u_char *pageaddr;
struct mypriv *priv=mtd->priv;
struct erase_info **tmp=&priv->cur_erases;
if (instr->len != mtd->erasesize)
return -EINVAL;
if (instr->addr + instr->len > mtd->size)
return -EINVAL;
pageaddr=pagein(mtd,instr->addr);
instr->mtd = mtd;
instr->dev = instr->addr >> priv->devshift;
instr->cell = (instr->addr - (instr->dev << priv->devshift)) / mtd->erasesize;
instr->next = NULL;
instr->state = MTD_ERASE_PENDING;
while (*tmp)
{
tmp = &((*tmp) -> next);
}
*tmp = instr;
flashcard_periodic((u_long)mtd);
return 0;
}
int flashcard_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
u_char *pageaddr=pagein(mtd,from);
struct mypriv *priv=mtd->priv;
u_char device = from >> priv->devshift;
u_char cell = (int) (from - (device << priv->devshift)) / mtd->erasesize;
int ret = 0, timeron = 0;
if ((from & WINDOW_MASK) + len <= WINDOW_SIZE)
*retlen = len;
else
*retlen = WINDOW_SIZE - (from & WINDOW_MASK);
if (priv->devstat[device])
{
/* There is an erase in progress or pending for this device. Stop it */
timeron = del_timer(&flashcard_timer);
if (priv->cur_erases && priv->cur_erases->cell == cell)
{
/* The erase is on the current cell. Just return all 0xff */
add_timer(&flashcard_timer);
printk("Cell %d currently erasing. Setting to all 0xff\n",cell);
memset(buf, 0xff, *retlen);
return 0;
}
if (priv->devstat[device] == MTD_ERASING)
{
ret = suspend_erase(pageaddr);
priv->devstat[device] = MTD_ERASE_SUSPEND;
if (ret)
{
printk("flashcard: failed to suspend erase\n");
add_timer (&flashcard_timer);
return ret;
}
}
}
writew(IF_READ_ARRAY, (u_long)pageaddr & ~1);
ret = 0;
memcpy (buf, pageaddr, *retlen);
writew(IF_READ_CSR, (u_long)pageaddr & ~1);
if (priv->devstat[device] & MTD_ERASE_SUSPEND)
{
resume_erase(pageaddr);
priv->devstat[device]=MTD_ERASING;
}
if (timeron) add_timer (&flashcard_timer);
return ret;
}
int flashcard_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
{
struct mypriv *priv = (struct mypriv *)mtd->priv;
u_char *endaddr, *startaddr;
register u_char *pageaddr;
u_char device = to >> priv->devshift;
/* jiffies_t oldj=jiffies;*/
int ret;
while (priv->devstat[device])
{
flashcard_sync(mtd);
}
if ((to & WINDOW_MASK) + len <= WINDOW_SIZE)
*retlen = len;
else
*retlen = WINDOW_SIZE - (to & WINDOW_MASK);
pageaddr = pagein(mtd, to);
startaddr = (u_char *)((u_long) pageaddr & ~1);
endaddr = pageaddr+(*retlen);
/* Set up to read */
writew(IF_READ_CSR, startaddr);
/* Make sure it's aligned by reading the first byte if necessary */
if (to & 1)
{
/* Unaligned access */
u_char cbuf;
cbuf = *buf;
if (!((u_long)pageaddr & 0xf))
schedule();
ret = byte_write(pageaddr, cbuf);
if (ret) return ret;
pageaddr++; buf++;
}
for ( ; pageaddr + 1 < endaddr; buf += 2, pageaddr += 2)
{
/* if ((u_long)pageaddr & 0xf) schedule();*/
ret = word_write(pageaddr, *(__u16 *)buf);
if (ret)
return ret;
}
if (pageaddr != endaddr)
{
/* One more byte to write at the end. */
u_char cbuf;
cbuf = *buf;
ret = byte_write(pageaddr, cbuf);
if (ret) return ret;
}
return check_write(startaddr);
/* printk("Time taken in flashcard_write: %lx jiffies\n",jiffies - oldj);*/
}
/*====================================================================*/
static inline int byte_write (volatile u_char *addr, u_char byte)
{
register u_char status;
register u_short i = 0;
do {
status = readb(addr);
if (status & CSR_WR_READY)
{
writeb(IF_WRITE & 0xff, addr);
writeb(byte, addr);
return 0;
}
i++;
} while(i < max_tries);
printk(KERN_NOTICE "flashcard: byte_write timed out, status 0x%x\n",status);
return -EIO;
}
static inline int word_write (volatile u_char *addr, __u16 word)
{
register u_short status;
register u_short i = 0;
do {
status = readw(addr);
if ((status & CSR_WR_READY) == CSR_WR_READY)
{
writew(IF_WRITE, addr);
writew(word, addr);
return 0;
}
i++;
} while(i < max_tries);
printk(KERN_NOTICE "flashcard: word_write timed out at %p, status 0x%x\n", addr, status);
return -EIO;
}
static inline void block_erase (volatile u_char *addr)
{
writew(IF_BLOCK_ERASE, addr);
writew(IF_CONFIRM, addr);
}
static inline int check_erase(volatile u_char *addr)
{
__u16 status;
/* writew(IF_READ_CSR, addr);*/
status = readw(addr);
if ((status & CSR_WR_READY) != CSR_WR_READY)
return -EBUSY;
if (status & (CSR_ERA_ERR | CSR_VPP_LOW | CSR_WR_ERR))
{
printk(KERN_NOTICE "flashcard: erase failed, status 0x%x\n",
status);
return -EIO;
}
return 0;
}
static inline int suspend_erase(volatile u_char *addr)
{
__u16 status;
u_long i = 0;
writew(IF_ERASE_SUSPEND, addr);
writew(IF_READ_CSR, addr);
do {
status = readw(addr);
if ((status & CSR_WR_READY) == CSR_WR_READY)
return 0;
i++;
} while(i < max_tries);
printk(KERN_NOTICE "flashcard: suspend_erase timed out, status 0x%x\n", status);
return -EIO;
}
static inline void resume_erase(volatile u_char *addr)
{
__u16 status;
writew(IF_READ_CSR, addr);
status = readw(addr);
/* Only give resume signal if the erase is really suspended */
if (status & CSR_ERA_SUSPEND)
writew(IF_CONFIRM, addr);
}
static inline void reset_block(volatile u_char *addr)
{
u_short i;
__u16 status;
writew(IF_CLEAR_CSR, addr);
for (i = 0; i < 100; i++) {
writew(IF_READ_CSR, addr);
status = readw(addr);
if (status != 0xffff) break;
udelay(1000);
}
writew(IF_READ_CSR, addr);
}
static inline int check_write(volatile u_char *addr)
{
u_short status, i = 0;
writew(IF_READ_CSR, addr);
do {
status = readw(addr);
if (status & (CSR_WR_ERR | CSR_VPP_LOW))
{
printk(KERN_NOTICE "flashcard: write failure at %p, status 0x%x\n", addr, status);
reset_block(addr);
return -EIO;
}
if ((status & CSR_WR_READY) == CSR_WR_READY)
return 0;
i++;
} while (i < max_tries);
printk(KERN_NOTICE "flashcard: write timed out at %p, status 0x%x\n", addr, status);
return -EIO;
}
/*====================================================================*/
static void flashcard_periodic(unsigned long data)
{
register struct mtd_info *mtd = (struct mtd_info *)data;
register struct mypriv *priv = mtd->priv;
struct erase_info *erase = priv->cur_erases;
u_char *pageaddr;
del_timer (&flashcard_timer);
if (!erase)
return;
pageaddr = pagein(mtd, erase->addr);
if (erase->state == MTD_ERASE_PENDING)
{
block_erase(pageaddr);
priv->devstat[erase->dev] = erase->state = MTD_ERASING;
erase->time = jiffies;
erase->retries = 0;
}
else if (erase->state == MTD_ERASING)
{
/* It's trying to erase. Check whether it's finished */
int ret = check_erase(pageaddr);
if (!ret)
{
/* It's finished OK */
priv->devstat[erase->dev] = 0;
priv->cur_erases = erase->next;
erase->state = MTD_ERASE_DONE;
if (erase->callback)
(*(erase->callback))(erase);
else
kfree(erase);
}
else if (ret == -EIO)
{
if (++erase->retries > retry_limit)
{
printk("Failed too many times. Giving up\n");
priv->cur_erases = erase->next;
priv->devstat[erase->dev] = 0;
erase->state = MTD_ERASE_FAILED;
if (erase->callback)
(*(erase->callback))(erase);
else
kfree(erase);
}
else
priv->devstat[erase->dev] = erase->state = MTD_ERASE_PENDING;
}
else if (erase->time + erase_timeout < jiffies)
{
printk("Flash erase timed out. The world is broken.\n");
/* Just ignore and hope it goes away. For a while, read ops will give the CSR
and writes won't work. */
priv->cur_erases = erase->next;
priv->devstat[erase->dev] = 0;
erase->state = MTD_ERASE_FAILED;
if (erase->callback)
(*(erase->callback))(erase);
else
kfree(erase);
}
}
if (priv->cur_erases)
{
flashcard_timer.expires = jiffies + HZ;
add_timer (&flashcard_timer);
}
else
wake_up_interruptible(&priv->wq);
}
int __init init_doc1000(void)
{
struct mypriv *priv;
if (!base)
{
printk(KERN_NOTICE "flashcard: No start address for memory device.\n");
return -EINVAL;
}
mymtd = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
if (!mymtd)
{
printk(KERN_NOTICE "physmem: Cannot allocate memory for new MTD device.\n");
return -ENOMEM;
}
memset(mymtd,0,sizeof(struct mtd_info));
mymtd->priv = (void *) kmalloc (sizeof(struct mypriv), GFP_KERNEL);
if (!mymtd->priv)
{
kfree(mymtd);
printk(KERN_NOTICE "physmem: Cannot allocate memory for new MTD device's private data.\n");
return -ENOMEM;
}
priv=mymtd->priv;
init_waitqueue_head(&priv->wq);
memset (priv,0,sizeof(struct mypriv));
priv->baseaddr = phys_to_virt(base);
priv->numdevices = 4;
mymtd->name = "M-Systems DiskOnChip 1000";
mymtd->size = 0x100000;
mymtd->flags = MTD_CLEAR_BITS | MTD_ERASEABLE;
mymtd->erase = flashcard_erase;
mymtd->point = NULL;
mymtd->unpoint = NULL;
mymtd->read = flashcard_read;
mymtd->write = flashcard_write;
mymtd->sync = flashcard_sync;
mymtd->erasesize = 0x10000;
// mymtd->interleave = 2;
priv->devshift = 24;
mymtd->type = MTD_NORFLASH;
if (add_mtd_device(mymtd))
{
printk(KERN_NOTICE "MTD device registration failed!\n");
kfree(mymtd->priv);
kfree(mymtd);
return -EAGAIN;
}
init_timer(&flashcard_timer);
flashcard_timer.function = flashcard_periodic;
flashcard_timer.data = (u_long)mymtd;
return 0;
}
static void __init cleanup_doc1000(void)
{
kfree (mymtd->priv);
del_mtd_device(mymtd);
kfree(mymtd);
}
module_init(init_doc1000);
module_exit(cleanup_doc1000);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("MTD driver for DiskOnChip 1000");
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