1 files changed, 256 insertions, 0 deletions

diff --git a/drivers/mtd/maps/scb2_flash.c b/drivers/mtd/maps/scb2_flash.c
new file mode 100644
index 000000000000..5bb3b600e5d0
--- /dev/null
+++ b/drivers/mtd/maps/scb2_flash.c
@@ -0,0 +1,256 @@
+/*
+ * MTD map driver for BIOS Flash on Intel SCB2 boards
+ * $Id: scb2_flash.c,v 1.11 2004/11/28 09:40:40 dwmw2 Exp $
+ * 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/config.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 != 1) {
+                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 = (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%x at offset 0x%x\n",
+               scb2_mtd->size, 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_module_init(&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);