/*
   * ichxrom.c
   *
   * Normal mappings of chips in physical memory
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <asm/io.h>
  #include <linux/mtd/mtd.h>
  #include <linux/mtd/map.h>
  #include <linux/mtd/cfi.h>
  #include <linux/mtd/flashchip.h>
  #include <linux/pci.h>
  #include <linux/pci_ids.h>
  #include <linux/list.h>
  
  #define xstr(s) str(s)
  #define str(s) #s
  #define MOD_NAME xstr(KBUILD_BASENAME)
  
  #define ADDRESS_NAME_LEN 18
  
  #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
  
  #define BIOS_CNTL	0x4e
  #define FWH_DEC_EN1	0xE3
  #define FWH_DEC_EN2	0xF0
  #define FWH_SEL1	0xE8
  #define FWH_SEL2	0xEE
  
  struct ichxrom_window {
  	void __iomem* virt;
  	unsigned long phys;
  	unsigned long size;
  	struct list_head maps;
  	struct resource rsrc;
  	struct pci_dev *pdev;
  };
  
  struct ichxrom_map_info {
  	struct list_head list;
  	struct map_info map;
  	struct mtd_info *mtd;
  	struct resource rsrc;
  	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
  };
  
  static struct ichxrom_window ichxrom_window = {
  	.maps = LIST_HEAD_INIT(ichxrom_window.maps),
  };
  
  static void ichxrom_cleanup(struct ichxrom_window *window)
  {
  	struct ichxrom_map_info *map, *scratch;
  	u16 word;
  
  	/* Disable writes through the rom window */
  	pci_read_config_word(window->pdev, BIOS_CNTL, &word);
  	pci_write_config_word(window->pdev, BIOS_CNTL, word & ~1);
  	pci_dev_put(window->pdev);
  
  	/* Free all of the mtd devices */
  	list_for_each_entry_safe(map, scratch, &window->maps, list) {
  		if (map->rsrc.parent)
  			release_resource(&map->rsrc);
  		mtd_device_unregister(map->mtd);
  		map_destroy(map->mtd);
  		list_del(&map->list);
  		kfree(map);
  	}
  	if (window->rsrc.parent)
  		release_resource(&window->rsrc);
  	if (window->virt) {
  		iounmap(window->virt);
  		window->virt = NULL;
  		window->phys = 0;
  		window->size = 0;
  		window->pdev = NULL;
  	}
  }
  
  
  static int ichxrom_init_one(struct pci_dev *pdev,
  			    const struct pci_device_id *ent)
  {
  	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
  	struct ichxrom_window *window = &ichxrom_window;
  	struct ichxrom_map_info *map = NULL;
  	unsigned long map_top;
  	u8 byte;
  	u16 word;
  
  	/* For now I just handle the ichx and I assume there
  	 * are not a lot of resources up at the top of the address
  	 * space.  It is possible to handle other devices in the
  	 * top 16MB but it is very painful.  Also since
  	 * you can only really attach a FWH to an ICHX there
  	 * a number of simplifications you can make.
  	 *
  	 * Also you can page firmware hubs if an 8MB window isn't enough
  	 * but don't currently handle that case either.
  	 */
  	window->pdev = pdev;
  
  	/* Find a region continuous to the end of the ROM window  */
  	window->phys = 0;
  	pci_read_config_byte(pdev, FWH_DEC_EN1, &byte);
  	if (byte == 0xff) {
  		window->phys = 0xffc00000;
  		pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
  		if ((byte & 0x0f) == 0x0f) {
  			window->phys = 0xff400000;
  		}
  		else if ((byte & 0x0e) == 0x0e) {
  			window->phys = 0xff500000;
  		}
  		else if ((byte & 0x0c) == 0x0c) {
  			window->phys = 0xff600000;
  		}
  		else if ((byte & 0x08) == 0x08) {
  			window->phys = 0xff700000;
  		}
  	}
  	else if ((byte & 0xfe) == 0xfe) {
  		window->phys = 0xffc80000;
  	}
  	else if ((byte & 0xfc) == 0xfc) {
  		window->phys = 0xffd00000;
  	}
  	else if ((byte & 0xf8) == 0xf8) {
  		window->phys = 0xffd80000;
  	}
  	else if ((byte & 0xf0) == 0xf0) {
  		window->phys = 0xffe00000;
  	}
  	else if ((byte & 0xe0) == 0xe0) {
  		window->phys = 0xffe80000;
  	}
  	else if ((byte & 0xc0) == 0xc0) {
  		window->phys = 0xfff00000;
  	}
  	else if ((byte & 0x80) == 0x80) {
  		window->phys = 0xfff80000;
  	}
  
  	if (window->phys == 0) {
  		printk(KERN_ERR MOD_NAME ": Rom window is closed
  ");
  		goto out;
  	}
  	window->phys -= 0x400000UL;
  	window->size = (0xffffffffUL - window->phys) + 1UL;
  
  	/* Enable writes through the rom window */
  	pci_read_config_word(pdev, BIOS_CNTL, &word);
  	if (!(word & 1)  && (word & (1<<1))) {
  		/* The BIOS will generate an error if I enable
  		 * this device, so don't even try.
  		 */
  		printk(KERN_ERR MOD_NAME ": firmware access control, I can't enable writes
  ");
  		goto out;
  	}
  	pci_write_config_word(pdev, BIOS_CNTL, word | 1);
  
  	/*
  	 * Try to reserve the window mem region.  If this fails then
  	 * it is likely due to the window being "reseved" by the BIOS.
  	 */
  	window->rsrc.name = MOD_NAME;
  	window->rsrc.start = window->phys;
  	window->rsrc.end   = window->phys + window->size - 1;
  	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
  	if (request_resource(&iomem_resource, &window->rsrc)) {
  		window->rsrc.parent = NULL;
  		printk(KERN_DEBUG MOD_NAME ": "
  		       "%s(): Unable to register resource %pR - kernel bug?
  ",
  		       __func__, &window->rsrc);
  	}
  
  	/* Map the firmware hub into my address space. */
  	window->virt = ioremap_nocache(window->phys, window->size);
  	if (!window->virt) {
  		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed
  ",
  			window->phys, window->size);
  		goto out;
  	}
  
  	/* Get the first address to look for an rom chip at */
  	map_top = window->phys;
  	if ((window->phys & 0x3fffff) != 0) {
  		map_top = window->phys + 0x400000;
  	}
  #if 1
  	/* The probe sequence run over the firmware hub lock
  	 * registers sets them to 0x7 (no access).
  	 * Probe at most the last 4M of the address space.
  	 */
  	if (map_top < 0xffc00000) {
  		map_top = 0xffc00000;
  	}
  #endif
  	/* Loop through and look for rom chips */
  	while((map_top - 1) < 0xffffffffUL) {
  		struct cfi_private *cfi;
  		unsigned long offset;
  		int i;
  
  		if (!map) {
  			map = kmalloc(sizeof(*map), GFP_KERNEL);
  		}
  		if (!map) {
  			printk(KERN_ERR MOD_NAME ": kmalloc failed");
  			goto out;
  		}
  		memset(map, 0, sizeof(*map));
  		INIT_LIST_HEAD(&map->list);
  		map->map.name = map->map_name;
  		map->map.phys = map_top;
  		offset = map_top - window->phys;
  		map->map.virt = (void __iomem *)
  			(((unsigned long)(window->virt)) + offset);
  		map->map.size = 0xffffffffUL - map_top + 1UL;
  		/* Set the name of the map to the address I am trying */
  		sprintf(map->map_name, "%s @%08Lx",
  			MOD_NAME, (unsigned long long)map->map.phys);
  
  		/* Firmware hubs only use vpp when being programmed
  		 * in a factory setting.  So in-place programming
  		 * needs to use a different method.
  		 */
  		for(map->map.bankwidth = 32; map->map.bankwidth;
  			map->map.bankwidth >>= 1)
  		{
  			char **probe_type;
  			/* Skip bankwidths that are not supported */
  			if (!map_bankwidth_supported(map->map.bankwidth))
  				continue;
  
  			/* Setup the map methods */
  			simple_map_init(&map->map);
  
  			/* Try all of the probe methods */
  			probe_type = rom_probe_types;
  			for(; *probe_type; probe_type++) {
  				map->mtd = do_map_probe(*probe_type, &map->map);
  				if (map->mtd)
  					goto found;
  			}
  		}
  		map_top += ROM_PROBE_STEP_SIZE;
  		continue;
  	found:
  		/* Trim the size if we are larger than the map */
  		if (map->mtd->size > map->map.size) {
  			printk(KERN_WARNING MOD_NAME
  				" rom(%llu) larger than window(%lu). fixing...
  ",
  				(unsigned long long)map->mtd->size, map->map.size);
  			map->mtd->size = map->map.size;
  		}
  		if (window->rsrc.parent) {
  			/*
  			 * Registering the MTD device in iomem may not be possible
  			 * if there is a BIOS "reserved" and BUSY range.  If this
  			 * fails then continue anyway.
  			 */
  			map->rsrc.name  = map->map_name;
  			map->rsrc.start = map->map.phys;
  			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
  			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
  			if (request_resource(&window->rsrc, &map->rsrc)) {
  				printk(KERN_ERR MOD_NAME
  					": cannot reserve MTD resource
  ");
  				map->rsrc.parent = NULL;
  			}
  		}
  
  		/* Make the whole region visible in the map */
  		map->map.virt = window->virt;
  		map->map.phys = window->phys;
  		cfi = map->map.fldrv_priv;
  		for(i = 0; i < cfi->numchips; i++) {
  			cfi->chips[i].start += offset;
  		}
  
  		/* Now that the mtd devices is complete claim and export it */
  		map->mtd->owner = THIS_MODULE;
  		if (mtd_device_register(map->mtd, NULL, 0)) {
  			map_destroy(map->mtd);
  			map->mtd = NULL;
  			goto out;
  		}
  
  
  		/* Calculate the new value of map_top */
  		map_top += map->mtd->size;
  
  		/* File away the map structure */
  		list_add(&map->list, &window->maps);
  		map = NULL;
  	}
  
   out:
  	/* Free any left over map structures */
  	kfree(map);
  
  	/* See if I have any map structures */
  	if (list_empty(&window->maps)) {
  		ichxrom_cleanup(window);
  		return -ENODEV;
  	}
  	return 0;
  }
  
  
  static void ichxrom_remove_one(struct pci_dev *pdev)
  {
  	struct ichxrom_window *window = &ichxrom_window;
  	ichxrom_cleanup(window);
  }
  
  static struct pci_device_id ichxrom_pci_tbl[] = {
  	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,
  	  PCI_ANY_ID, PCI_ANY_ID, },
  	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
  	  PCI_ANY_ID, PCI_ANY_ID, },
  	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
  	  PCI_ANY_ID, PCI_ANY_ID, },
  	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,
  	  PCI_ANY_ID, PCI_ANY_ID, },
  	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,
  	  PCI_ANY_ID, PCI_ANY_ID, },
  	{ 0, },
  };
  
  #if 0
  MODULE_DEVICE_TABLE(pci, ichxrom_pci_tbl);
  
  static struct pci_driver ichxrom_driver = {
  	.name =		MOD_NAME,
  	.id_table =	ichxrom_pci_tbl,
  	.probe =	ichxrom_init_one,
  	.remove =	ichxrom_remove_one,
  };
  #endif
  
  static int __init init_ichxrom(void)
  {
  	struct pci_dev *pdev;
  	struct pci_device_id *id;
  
  	pdev = NULL;
  	for (id = ichxrom_pci_tbl; id->vendor; id++) {
  		pdev = pci_get_device(id->vendor, id->device, NULL);
  		if (pdev) {
  			break;
  		}
  	}
  	if (pdev) {
  		return ichxrom_init_one(pdev, &ichxrom_pci_tbl[0]);
  	}
  	return -ENXIO;
  #if 0
  	return pci_register_driver(&ichxrom_driver);
  #endif
  }
  
  static void __exit cleanup_ichxrom(void)
  {
  	ichxrom_remove_one(ichxrom_window.pdev);
  }
  
  module_init(init_ichxrom);
  module_exit(cleanup_ichxrom);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
  MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ICHX southbridge");