linux/drivers/mtd/maps/scb2_flash.c
Adrian Hunter 69423d99fc [MTD] update internal API to support 64-bit device size
MTD internal API presently uses 32-bit values to represent
device size.  This patch updates them to 64-bits but leaves
the external API unchanged.  Extending the external API
is a separate issue for several reasons.  First, no one
needs it at the moment.  Secondly, whether the implementation
is done with IOCTLs, sysfs or both is still debated.  Thirdly
external API changes require the internal API to be accepted
first.

Note that although the MTD API will be able to support 64-bit
device sizes, existing drivers do not and are not required
to do so, although NAND base has been updated.

In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
    	- printk message formats
    	- division and modulus of 64-bit values
    	- NAND base support
	- 32-bit local variables used by mtdpart and mtdconcat
	- naughtily assuming one structure maps to another
	in MEMERASE ioctl

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-12-10 13:37:21 +00:00

257 lines
7.4 KiB
C

/*
* MTD map driver for BIOS Flash on Intel SCB2 boards
* Copyright (C) 2002 Sun Microsystems, Inc.
* Tim Hockin <thockin@sun.com>
*
* A few notes on this MTD map:
*
* This was developed with a small number of SCB2 boards to test on.
* Hopefully, Intel has not introducted too many unaccounted variables in the
* making of this board.
*
* The BIOS marks its own memory region as 'reserved' in the e820 map. We
* try to request it here, but if it fails, we carry on anyway.
*
* This is how the chip is attached, so said the schematic:
* * a 4 MiB (32 Mib) 16 bit chip
* * a 1 MiB memory region
* * A20 and A21 pulled up
* * D8-D15 ignored
* What this means is that, while we are addressing bytes linearly, we are
* really addressing words, and discarding the other byte. This means that
* the chip MUST BE at least 2 MiB. This also means that every block is
* actually half as big as the chip reports. It also means that accesses of
* logical address 0 hit higher-address sections of the chip, not physical 0.
* One can only hope that these 4MiB x16 chips were a lot cheaper than 1MiB x8
* chips.
*
* This driver assumes the chip is not write-protected by an external signal.
* As of the this writing, that is true, but may change, just to spite me.
*
* The actual BIOS layout has been mostly reverse engineered. Intel BIOS
* updates for this board include 10 related (*.bio - &.bi9) binary files and
* another separate (*.bbo) binary file. The 10 files are 64k of data + a
* small header. If the headers are stripped off, the 10 64k files can be
* concatenated into a 640k image. This is your BIOS image, proper. The
* separate .bbo file also has a small header. It is the 'Boot Block'
* recovery BIOS. Once the header is stripped, no further prep is needed.
* As best I can tell, the BIOS is arranged as such:
* offset 0x00000 to 0x4ffff (320k): unknown - SCSI BIOS, etc?
* offset 0x50000 to 0xeffff (640k): BIOS proper
* offset 0xf0000 ty 0xfffff (64k): Boot Block region
*
* Intel's BIOS update program flashes the BIOS and Boot Block in separate
* steps. Probably a wise thing to do.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/cfi.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#define MODNAME "scb2_flash"
#define SCB2_ADDR 0xfff00000
#define SCB2_WINDOW 0x00100000
static void __iomem *scb2_ioaddr;
static struct mtd_info *scb2_mtd;
static struct map_info scb2_map = {
.name = "SCB2 BIOS Flash",
.size = 0,
.bankwidth = 1,
};
static int region_fail;
static int __devinit
scb2_fixup_mtd(struct mtd_info *mtd)
{
int i;
int done = 0;
struct map_info *map = mtd->priv;
struct cfi_private *cfi = map->fldrv_priv;
/* barf if this doesn't look right */
if (cfi->cfiq->InterfaceDesc != CFI_INTERFACE_X16_ASYNC) {
printk(KERN_ERR MODNAME ": unsupported InterfaceDesc: %#x\n",
cfi->cfiq->InterfaceDesc);
return -1;
}
/* I wasn't here. I didn't see. dwmw2. */
/* the chip is sometimes bigger than the map - what a waste */
mtd->size = map->size;
/*
* We only REALLY get half the chip, due to the way it is
* wired up - D8-D15 are tossed away. We read linear bytes,
* but in reality we are getting 1/2 of each 16-bit read,
* which LOOKS linear to us. Because CFI code accounts for
* things like lock/unlock/erase by eraseregions, we need to
* fudge them to reflect this. Erases go like this:
* * send an erase to an address
* * the chip samples the address and erases the block
* * add the block erasesize to the address and repeat
* -- the problem is that addresses are 16-bit addressable
* -- we end up erasing every-other block
*/
mtd->erasesize /= 2;
for (i = 0; i < mtd->numeraseregions; i++) {
struct mtd_erase_region_info *region = &mtd->eraseregions[i];
region->erasesize /= 2;
}
/*
* If the chip is bigger than the map, it is wired with the high
* address lines pulled up. This makes us access the top portion of
* the chip, so all our erase-region info is wrong. Start cutting from
* the bottom.
*/
for (i = 0; !done && i < mtd->numeraseregions; i++) {
struct mtd_erase_region_info *region = &mtd->eraseregions[i];
if (region->numblocks * region->erasesize > mtd->size) {
region->numblocks = ((unsigned long)mtd->size /
region->erasesize);
done = 1;
} else {
region->numblocks = 0;
}
region->offset = 0;
}
return 0;
}
/* CSB5's 'Function Control Register' has bits for decoding @ >= 0xffc00000 */
#define CSB5_FCR 0x41
#define CSB5_FCR_DECODE_ALL 0x0e
static int __devinit
scb2_flash_probe(struct pci_dev *dev, const struct pci_device_id *ent)
{
u8 reg;
/* enable decoding of the flash region in the south bridge */
pci_read_config_byte(dev, CSB5_FCR, &reg);
pci_write_config_byte(dev, CSB5_FCR, reg | CSB5_FCR_DECODE_ALL);
if (!request_mem_region(SCB2_ADDR, SCB2_WINDOW, scb2_map.name)) {
/*
* The BIOS seems to mark the flash region as 'reserved'
* in the e820 map. Warn and go about our business.
*/
printk(KERN_WARNING MODNAME
": warning - can't reserve rom window, continuing\n");
region_fail = 1;
}
/* remap the IO window (w/o caching) */
scb2_ioaddr = ioremap_nocache(SCB2_ADDR, SCB2_WINDOW);
if (!scb2_ioaddr) {
printk(KERN_ERR MODNAME ": Failed to ioremap window!\n");
if (!region_fail)
release_mem_region(SCB2_ADDR, SCB2_WINDOW);
return -ENOMEM;
}
scb2_map.phys = SCB2_ADDR;
scb2_map.virt = scb2_ioaddr;
scb2_map.size = SCB2_WINDOW;
simple_map_init(&scb2_map);
/* try to find a chip */
scb2_mtd = do_map_probe("cfi_probe", &scb2_map);
if (!scb2_mtd) {
printk(KERN_ERR MODNAME ": flash probe failed!\n");
iounmap(scb2_ioaddr);
if (!region_fail)
release_mem_region(SCB2_ADDR, SCB2_WINDOW);
return -ENODEV;
}
scb2_mtd->owner = THIS_MODULE;
if (scb2_fixup_mtd(scb2_mtd) < 0) {
del_mtd_device(scb2_mtd);
map_destroy(scb2_mtd);
iounmap(scb2_ioaddr);
if (!region_fail)
release_mem_region(SCB2_ADDR, SCB2_WINDOW);
return -ENODEV;
}
printk(KERN_NOTICE MODNAME ": chip size 0x%llx at offset 0x%llx\n",
(unsigned long long)scb2_mtd->size,
(unsigned long long)(SCB2_WINDOW - scb2_mtd->size));
add_mtd_device(scb2_mtd);
return 0;
}
static void __devexit
scb2_flash_remove(struct pci_dev *dev)
{
if (!scb2_mtd)
return;
/* disable flash writes */
if (scb2_mtd->lock)
scb2_mtd->lock(scb2_mtd, 0, scb2_mtd->size);
del_mtd_device(scb2_mtd);
map_destroy(scb2_mtd);
iounmap(scb2_ioaddr);
scb2_ioaddr = NULL;
if (!region_fail)
release_mem_region(SCB2_ADDR, SCB2_WINDOW);
pci_set_drvdata(dev, NULL);
}
static struct pci_device_id scb2_flash_pci_ids[] = {
{
.vendor = PCI_VENDOR_ID_SERVERWORKS,
.device = PCI_DEVICE_ID_SERVERWORKS_CSB5,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID
},
{ 0, }
};
static struct pci_driver scb2_flash_driver = {
.name = "Intel SCB2 BIOS Flash",
.id_table = scb2_flash_pci_ids,
.probe = scb2_flash_probe,
.remove = __devexit_p(scb2_flash_remove),
};
static int __init
scb2_flash_init(void)
{
return pci_register_driver(&scb2_flash_driver);
}
static void __exit
scb2_flash_exit(void)
{
pci_unregister_driver(&scb2_flash_driver);
}
module_init(scb2_flash_init);
module_exit(scb2_flash_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tim Hockin <thockin@sun.com>");
MODULE_DESCRIPTION("MTD map driver for Intel SCB2 BIOS Flash");
MODULE_DEVICE_TABLE(pci, scb2_flash_pci_ids);