drivers/mtd/maps/scb2_flash.c - arm/linux-arm64-legacy - Git at Google

 /*
  * MTD map driver for BIOS Flash on Intel SCB2 boards
  * $Id: scb2_flash.c,v 1.12 2005/03/18 14:04:35 gleixner 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_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);
	/*
	* MTD map driver for BIOS Flash on Intel SCB2 boards
	* $Id: scb2_flash.c,v 1.12 2005/03/18 14:04:35 gleixner 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_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);