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/*
* sheevaplug nand flash driver
*
* for now separate from (inferno's) os/port/flashnand.c because the flash
* seems newer, and has different commands, but that is nand-chip specific,
* not sheevaplug-specific. they should be merged in future.
*
* the sheevaplug has a hynix 4gbit flash chip: hy27uf084g2m.
* 2048 byte pages, with 64 spare bytes each; erase block size is 128k.
*
* it has a "glueless" interface, at 0xf9000000. that's the address
* of the data register. the command and address registers are those
* or'ed with 1 and 2 respectively.
*
* linux uses this layout for the nand flash (from address 0 onwards):
* 1mb for u-boot
* 4mb for kernel
* 507mb for file system
*
* this is not so relevant here except for ecc. the first two areas
* (u-boot and kernel) are expected to have 4-bit ecc per 512 bytes
* (but calculated from last byte to first), bad erase blocks skipped.
* the file system area has 1-bit ecc per 256 bytes.
*/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/error.h"
#include "../port/flashif.h"
#include "../port/nandecc.h"
enum {
Debug = 0,
Nopage = ~0ul, /* cache is empty */
/* vendors */
Hynix = 0xad,
Samsung = 0xec,
/* chips */
Hy27UF084G2M = 0xdc,
NandActCEBoot = 1<<1,
};
typedef struct Nandreg Nandreg;
typedef struct Nandtab Nandtab;
typedef struct Cache Cache;
struct Nandreg { /* hw registers */
ulong rdparms;
ulong wrparms;
uchar _pad0[0x70 - 0x20];
ulong ctl;
};
struct Nandtab {
int vid;
int did;
vlong size;
char* name;
};
struct Cache {
Flash *flif;
ulong pageno;
ulong pgsize; /* r->pagesize */
char *page; /* of pgsize bytes */
};
enum {
/* commands */
Readstatus = 0x70,
Readid = 0x90, /* needs 1 0-address write */
Resetf = 0xff,
/*
* needs 5 address writes followed by Readstart,
* Readstartcache or Restartcopy.
*/
Read = 0x00,
Readstart = 0x30,
Readstartcache = 0x31,
Readstartcopy = 0x35,
/* after Readstartcache, to stop reading next pages */
Readstopcache = 0x34,
/* needs 5 address writes, the data, and -start or -cache */
Program = 0x80,
Programstart = 0x10,
Programcache = 0x15,
Copyback = 0x85, /* followed by Programstart */
/* 3 address writes for block followed by Erasestart */
Erase = 0x60,
Erasestart = 0xd0,
Randomread = 0x85,
Randomwrite = 0x05,
Randomwritestart= 0xe0,
/* status bits */
SFail = 1<<0,
SCachefail = 1<<1,
SIdle = 1<<5, /* doesn't seem to come on ever */
SReady = 1<<6,
SNotprotected = 1<<7,
Srdymask = SReady, /* was SIdle|SReady */
};
Nandtab nandtab[] = {
{Hynix, Hy27UF084G2M, 512*MB, "Hy27UF084G2M"},
{Samsung, 0xdc, 512*MB, "Samsung 2Gb"},
};
static Cache cache;
static void
nandcmd(Flash *f, uchar b)
{
uchar *p = (uchar *)((ulong)f->addr|1);
*p = b;
coherence();
}
static void
nandaddr(Flash *f, uchar b)
{
uchar *p = (uchar *)((ulong)f->addr|2);
*p = b;
coherence();
}
static uchar
nandread(Flash *f)
{
return *(uchar *)f->addr;
}
static void
nandreadn(Flash *f, uchar *buf, long n)
{
uchar *p = f->addr;
while(n-- > 0)
*buf++ = *p;
}
static void
nandwrite(Flash *f, uchar b)
{
*(uchar *)f->addr = b;
coherence();
}
static void
nandwriten(Flash *f, uchar *buf, long n)
{
uchar *p = f->addr;
while(n-- > 0)
*p = *buf++;
coherence();
}
static void
nandclaim(Flash*)
{
Nandreg *nand = (Nandreg*)soc.nand;
nand->ctl |= NandActCEBoot;
coherence();
}
static void
nandunclaim(Flash*)
{
Nandreg *nand = (Nandreg*)soc.nand;
nand->ctl &= ~NandActCEBoot;
coherence();
}
Nandtab *
findflash(Flash *f, uintptr pa, uchar *id4p)
{
int i;
ulong sts;
uchar maker, device, id3, id4;
Nandtab *chip;
mmuidmap(pa, 16);
f->addr = (void *)pa;
/* make sure controller is idle */
nandclaim(f);
nandcmd(f, Resetf);
nandunclaim(f);
nandclaim(f);
nandcmd(f, Readstatus);
sts = nandread(f);
nandunclaim(f);
for (i = 10; i > 0 && !(sts & SReady); i--) {
delay(50);
nandclaim(f);
nandcmd(f, Readstatus);
sts = nandread(f);
nandunclaim(f);
}
if(!(sts & SReady)) {
if (Debug)
print("flashkw: ctlr %#p not ready\n", pa);
return nil;
}
nandclaim(f);
nandcmd(f, Readid);
nandaddr(f, 0);
maker = nandread(f);
device = nandread(f);
id3 = nandread(f);
USED(id3);
id4 = nandread(f);
nandunclaim(f);
if (id4p)
*id4p = id4;
for(i = 0; i < nelem(nandtab); i++) {
chip = &nandtab[i];
if(chip->vid == maker && chip->did == device)
return chip;
}
print("flashkw: unknown chip: vid %#ux did %#ux\n", maker, device);
return nil;
}
int
flashat(Flash *f, uintptr pa)
{
return findflash(f, pa, nil) != nil;
}
static int
idchip(Flash *f)
{
uchar id4;
Flashregion *r;
Nandtab *chip;
static int blocksizes[4] = { 64*1024, 128*1024, 256*1024, 0 };
static int pagesizes[4] = { 1024, 2*1024, 0, 0 };
static int spares[2] = { 8, 16 }; /* per 512 bytes */
f->id = 0;
f->devid = 0;
f->width = 1;
chip = findflash(f, (uintptr)f->addr, &id4);
if (chip == nil)
return -1;
f->id = chip->vid;
f->devid = chip->did;
f->size = chip->size;
f->width = 1;
f->nr = 1;
r = &f->regions[0];
r->pagesize = pagesizes[id4 & MASK(2)];
r->erasesize = blocksizes[(id4 >> 4) & MASK(2)];
if (r->pagesize == 0 || r->erasesize == 0) {
iprint("flashkw: bogus flash sizes\n");
return -1;
}
r->n = f->size / r->erasesize;
r->start = 0;
r->end = f->size;
assert(ispow2(r->pagesize));
r->pageshift = log2(r->pagesize);
assert(ispow2(r->erasesize));
r->eraseshift = log2(r->erasesize);
assert(r->eraseshift >= r->pageshift);
if (cache.page == nil) {
cache.pgsize = r->pagesize;
cache.page = smalloc(r->pagesize);
}
r->spares = r->pagesize / 512 * spares[(id4 >> 2) & 1];
print("#F0: kwnand: %s %,lud bytes pagesize %lud erasesize %,lud"
" spares per page %lud\n", chip->name, f->size, r->pagesize,
r->erasesize, r->spares);
return 0;
}
static int
ctlrwait(Flash *f)
{
int sts, cnt;
nandclaim(f);
for (;;) {
nandcmd(f, Readstatus);
for(cnt = 100; cnt > 0 && (nandread(f) & Srdymask) != Srdymask;
cnt--)
microdelay(50);
nandcmd(f, Readstatus);
sts = nandread(f);
if((sts & Srdymask) == Srdymask)
break;
print("flashkw: flash ctlr busy, sts %#ux: resetting\n", sts);
nandcmd(f, Resetf);
}
nandunclaim(f);
return 0;
}
static int
erasezone(Flash *f, Flashregion *r, ulong offset)
{
int i;
ulong page, block;
uchar s;
if (Debug) {
print("flashkw: erasezone: offset %#lux, region nblocks %d,"
" start %#lux, end %#lux\n", offset, r->n, r->start,
r->end);
print(" erasesize %lud, pagesize %lud\n",
r->erasesize, r->pagesize);
}
assert(r->erasesize != 0);
if(offset & (r->erasesize - 1)) {
print("flashkw: erase offset %lud not block aligned\n", offset);
return -1;
}
page = offset >> r->pageshift;
block = page >> (r->eraseshift - r->pageshift);
if (Debug)
print("flashkw: erase: block %#lux\n", block);
/* make sure controller is idle */
if(ctlrwait(f) < 0) {
print("flashkw: erase: flash busy\n");
return -1;
}
/* start erasing */
nandclaim(f);
nandcmd(f, Erase);
nandaddr(f, page>>0);
nandaddr(f, page>>8);
nandaddr(f, page>>16);
nandcmd(f, Erasestart);
/* invalidate cache on any erasure (slight overkill) */
cache.pageno = Nopage;
/* have to wait until flash is done. typically ~2ms */
delay(1);
nandcmd(f, Readstatus);
for(i = 0; i < 100; i++) {
s = nandread(f);
if(s & SReady) {
nandunclaim(f);
if(s & SFail) {
print("flashkw: erase: failed, block %#lux\n",
block);
return -1;
}
return 0;
}
microdelay(50);
}
print("flashkw: erase timeout, block %#lux\n", block);
nandunclaim(f);
return -1;
}
static void
flcachepage(Flash *f, ulong page, uchar *buf)
{
Flashregion *r = &f->regions[0];
assert(cache.pgsize == r->pagesize);
cache.flif = f;
cache.pageno = page;
/* permit i/o directly to or from the cache */
if (buf != (uchar *)cache.page)
memmove(cache.page, buf, cache.pgsize);
}
static int
write1page(Flash *f, ulong offset, void *buf)
{
int i;
ulong page, v;
uchar s;
uchar *eccp, *p;
Flashregion *r = &f->regions[0];
static uchar *oob;
if (oob == nil)
oob = smalloc(r->spares);
page = offset >> r->pageshift;
if (Debug)
print("flashkw: write nand offset %#lux page %#lux\n",
offset, page);
if(offset & (r->pagesize - 1)) {
print("flashkw: write offset %lud not page aligned\n", offset);
return -1;
}
p = buf;
memset(oob, 0xff, r->spares);
assert(r->spares >= 24);
eccp = oob + r->spares - 24;
for(i = 0; i < r->pagesize / 256; i++) {
v = nandecc(p);
*eccp++ = v>>8;
*eccp++ = v>>0;
*eccp++ = v>>16;
p += 256;
}
if(ctlrwait(f) < 0) {
print("flashkw: write: nand not ready & idle\n");
return -1;
}
/* write, only whole pages for now, no sub-pages */
nandclaim(f);
nandcmd(f, Program);
nandaddr(f, 0);
nandaddr(f, 0);
nandaddr(f, page>>0);
nandaddr(f, page>>8);
nandaddr(f, page>>16);
nandwriten(f, buf, r->pagesize);
nandwriten(f, oob, r->spares);
nandcmd(f, Programstart);
microdelay(100);
nandcmd(f, Readstatus);
for(i = 0; i < 100; i++) {
s = nandread(f);
if(s & SReady) {
nandunclaim(f);
if(s & SFail) {
print("flashkw: write failed, page %#lux\n",
page);
return -1;
}
return 0;
}
microdelay(10);
}
nandunclaim(f);
flcachepage(f, page, buf);
print("flashkw: write timeout for page %#lux\n", page);
return -1;
}
static int
read1page(Flash *f, ulong offset, void *buf)
{
int i;
ulong addr, page, w;
uchar *eccp, *p;
Flashregion *r = &f->regions[0];
static uchar *oob;
if (oob == nil)
oob = smalloc(r->spares);
assert(r->pagesize != 0);
addr = offset & (r->pagesize - 1);
page = offset >> r->pageshift;
if(addr != 0) {
print("flashkw: read1page: read addr %#lux:"
" must read aligned page\n", addr);
return -1;
}
/* satisfy request from cache if possible */
if (f == cache.flif && page == cache.pageno &&
r->pagesize == cache.pgsize) {
memmove(buf, cache.page, r->pagesize);
return 0;
}
if (Debug)
print("flashkw: read offset %#lux addr %#lux page %#lux\n",
offset, addr, page);
nandclaim(f);
nandcmd(f, Read);
nandaddr(f, addr>>0);
nandaddr(f, addr>>8);
nandaddr(f, page>>0);
nandaddr(f, page>>8);
nandaddr(f, page>>16);
nandcmd(f, Readstart);
microdelay(50);
nandreadn(f, buf, r->pagesize);
nandreadn(f, oob, r->spares);
nandunclaim(f);
/* verify/correct data. last 8*3 bytes is ecc, per 256 bytes. */
p = buf;
assert(r->spares >= 24);
eccp = oob + r->spares - 24;
for(i = 0; i < r->pagesize / 256; i++) {
w = eccp[0] << 8 | eccp[1] << 0 | eccp[2] << 16;
eccp += 3;
switch(nandecccorrect(p, nandecc(p), &w, 1)) {
case NandEccErrorBad:
print("(page %d)\n", i);
return -1;
case NandEccErrorOneBit:
case NandEccErrorOneBitInEcc:
print("(page %d)\n", i);
/* fall through */
case NandEccErrorGood:
break;
}
p += 256;
}
flcachepage(f, page, buf);
return 0;
}
/*
* read a page at offset into cache, copy fragment from buf into it
* at pagoff, and rewrite that page.
*/
static int
rewrite(Flash *f, ulong offset, ulong pagoff, void *buf, ulong size)
{
if (read1page(f, offset, cache.page) < 0)
return -1;
memmove(&cache.page[pagoff], buf, size);
return write1page(f, offset, cache.page);
}
/* there are no alignment constraints on offset, buf, nor n */
static int
write(Flash *f, ulong offset, void *buf, long n)
{
uint un, frag, pagoff;
ulong pgsize;
uchar *p;
Flashregion *r = &f->regions[0];
if(n <= 0)
panic("flashkw: write: non-positive count %ld", n);
un = n;
assert(r->pagesize != 0);
pgsize = r->pagesize;
/* if a partial first page exists, update the first page with it. */
p = buf;
pagoff = offset % pgsize;
if (pagoff != 0) {
frag = pgsize - pagoff;
if (frag > un) /* might not extend to end of page */
frag = un;
if (rewrite(f, offset - pagoff, pagoff, p, frag) < 0)
return -1;
offset += frag;
p += frag;
un -= frag;
}
/* copy whole pages */
while (un >= pgsize) {
if (write1page(f, offset, p) < 0)
return -1;
offset += pgsize;
p += pgsize;
un -= pgsize;
}
/* if a partial last page exists, update the last page with it. */
if (un > 0)
return rewrite(f, offset, 0, p, un);
return 0;
}
/* there are no alignment constraints on offset, buf, nor n */
static int
read(Flash *f, ulong offset, void *buf, long n)
{
uint un, frag, pagoff;
ulong pgsize;
uchar *p;
Flashregion *r = &f->regions[0];
if(n <= 0)
panic("flashkw: read: non-positive count %ld", n);
un = n;
assert(r->pagesize != 0);
pgsize = r->pagesize;
/* if partial 1st page, read it into cache & copy fragment to buf */
p = buf;
pagoff = offset % pgsize;
if (pagoff != 0) {
frag = pgsize - pagoff;
if (frag > un) /* might not extend to end of page */
frag = un;
if (read1page(f, offset - pagoff, cache.page) < 0)
return -1;
offset += frag;
memmove(p, &cache.page[pagoff], frag);
p += frag;
un -= frag;
}
/* copy whole pages */
while (un >= pgsize) {
if (read1page(f, offset, p) < 0)
return -1;
offset += pgsize;
p += pgsize;
un -= pgsize;
}
/* if partial last page, read into cache & copy initial fragment to buf */
if (un > 0) {
if (read1page(f, offset, cache.page) < 0)
return -1;
memmove(p, cache.page, un);
}
return 0;
}
static int
reset(Flash *f)
{
if(f->data != nil)
return 1;
f->write = write;
f->read = read;
f->eraseall = nil;
f->erasezone = erasezone;
f->suspend = nil;
f->resume = nil;
f->sort = "nand";
cache.pageno = Nopage;
return idchip(f);
}
void
flashkwlink(void)
{
addflashcard("nand", reset);
}