linux/drivers/mtd/chips/gen_probe.c
Russell King 6170b43401 [MTD] Fix MTD device probing
Try larger numbers of chips before smaller
numbers of chips across the bus width.

This means we'll avoid misdetecting a 2 x16 array as 1 x32 if the
high 16-bits happen to read as zeros in the QRY area.

Signed-off-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2005-05-23 12:15:15 +02:00

256 lines
6.5 KiB
C

/*
* Routines common to all CFI-type probes.
* (C) 2001-2003 Red Hat, Inc.
* GPL'd
* $Id: gen_probe.c,v 1.22 2005/01/24 23:49:50 rmk Exp $
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/cfi.h>
#include <linux/mtd/gen_probe.h>
static struct mtd_info *check_cmd_set(struct map_info *, int);
static struct cfi_private *genprobe_ident_chips(struct map_info *map,
struct chip_probe *cp);
static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
struct cfi_private *cfi);
struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
{
struct mtd_info *mtd = NULL;
struct cfi_private *cfi;
/* First probe the map to see if we have CFI stuff there. */
cfi = genprobe_ident_chips(map, cp);
if (!cfi)
return NULL;
map->fldrv_priv = cfi;
/* OK we liked it. Now find a driver for the command set it talks */
mtd = check_cmd_set(map, 1); /* First the primary cmdset */
if (!mtd)
mtd = check_cmd_set(map, 0); /* Then the secondary */
if (mtd)
return mtd;
printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
kfree(cfi->cfiq);
kfree(cfi);
map->fldrv_priv = NULL;
return NULL;
}
EXPORT_SYMBOL(mtd_do_chip_probe);
static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
{
struct cfi_private cfi;
struct cfi_private *retcfi;
unsigned long *chip_map;
int i, j, mapsize;
int max_chips;
memset(&cfi, 0, sizeof(cfi));
/* Call the probetype-specific code with all permutations of
interleave and device type, etc. */
if (!genprobe_new_chip(map, cp, &cfi)) {
/* The probe didn't like it */
printk(KERN_DEBUG "%s: Found no %s device at location zero\n",
cp->name, map->name);
return NULL;
}
#if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
probe routines won't ever return a broken CFI structure anyway,
because they make them up themselves.
*/
if (cfi.cfiq->NumEraseRegions == 0) {
printk(KERN_WARNING "Number of erase regions is zero\n");
kfree(cfi.cfiq);
return NULL;
}
#endif
cfi.chipshift = cfi.cfiq->DevSize;
if (cfi_interleave_is_1(&cfi)) {
;
} else if (cfi_interleave_is_2(&cfi)) {
cfi.chipshift++;
} else if (cfi_interleave_is_4((&cfi))) {
cfi.chipshift += 2;
} else if (cfi_interleave_is_8(&cfi)) {
cfi.chipshift += 3;
} else {
BUG();
}
cfi.numchips = 1;
/*
* Allocate memory for bitmap of valid chips.
* Align bitmap storage size to full byte.
*/
max_chips = map->size >> cfi.chipshift;
mapsize = (max_chips / 8) + ((max_chips % 8) ? 1 : 0);
chip_map = kmalloc(mapsize, GFP_KERNEL);
if (!chip_map) {
printk(KERN_WARNING "%s: kmalloc failed for CFI chip map\n", map->name);
kfree(cfi.cfiq);
return NULL;
}
memset (chip_map, 0, mapsize);
set_bit(0, chip_map); /* Mark first chip valid */
/*
* Now probe for other chips, checking sensibly for aliases while
* we're at it. The new_chip probe above should have let the first
* chip in read mode.
*/
for (i = 1; i < max_chips; i++) {
cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
}
/*
* Now allocate the space for the structures we need to return to
* our caller, and copy the appropriate data into them.
*/
retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);
if (!retcfi) {
printk(KERN_WARNING "%s: kmalloc failed for CFI private structure\n", map->name);
kfree(cfi.cfiq);
kfree(chip_map);
return NULL;
}
memcpy(retcfi, &cfi, sizeof(cfi));
memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
if(test_bit(i, chip_map)) {
struct flchip *pchip = &retcfi->chips[j++];
pchip->start = (i << cfi.chipshift);
pchip->state = FL_READY;
init_waitqueue_head(&pchip->wq);
spin_lock_init(&pchip->_spinlock);
pchip->mutex = &pchip->_spinlock;
}
}
kfree(chip_map);
return retcfi;
}
static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
struct cfi_private *cfi)
{
int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
int max_chips = map_bankwidth(map); /* And minimum 1 */
int nr_chips, type;
for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
if (!cfi_interleave_supported(nr_chips))
continue;
cfi->interleave = nr_chips;
/* Minimum device size. Don't look for one 8-bit device
in a 16-bit bus, etc. */
type = map_bankwidth(map) / nr_chips;
for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
cfi->device_type = type;
if (cp->probe_chip(map, 0, NULL, cfi))
return 1;
}
}
return 0;
}
typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
extern cfi_cmdset_fn_t cfi_cmdset_0001;
extern cfi_cmdset_fn_t cfi_cmdset_0002;
extern cfi_cmdset_fn_t cfi_cmdset_0020;
static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
int primary)
{
struct cfi_private *cfi = map->fldrv_priv;
__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
#if defined(CONFIG_MODULES) && defined(HAVE_INTER_MODULE)
char probename[32];
cfi_cmdset_fn_t *probe_function;
sprintf(probename, "cfi_cmdset_%4.4X", type);
probe_function = inter_module_get_request(probename, probename);
if (probe_function) {
struct mtd_info *mtd;
mtd = (*probe_function)(map, primary);
/* If it was happy, it'll have increased its own use count */
inter_module_put(probename);
return mtd;
}
#endif
printk(KERN_NOTICE "Support for command set %04X not present\n",
type);
return NULL;
}
static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
{
struct cfi_private *cfi = map->fldrv_priv;
__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
if (type == P_ID_NONE || type == P_ID_RESERVED)
return NULL;
switch(type){
/* Urgh. Ifdefs. The version with weak symbols was
* _much_ nicer. Shame it didn't seem to work on
* anything but x86, really.
* But we can't rely in inter_module_get() because
* that'd mean we depend on link order.
*/
#ifdef CONFIG_MTD_CFI_INTELEXT
case 0x0001:
case 0x0003:
return cfi_cmdset_0001(map, primary);
#endif
#ifdef CONFIG_MTD_CFI_AMDSTD
case 0x0002:
return cfi_cmdset_0002(map, primary);
#endif
#ifdef CONFIG_MTD_CFI_STAA
case 0x0020:
return cfi_cmdset_0020(map, primary);
#endif
}
return cfi_cmdset_unknown(map, primary);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Helper routines for flash chip probe code");