/*
   * mm.c - Micro Memory(tm) PCI memory board block device driver - v2.3
   *
   * (C) 2001 San Mehat <nettwerk@valinux.com>
   * (C) 2001 Johannes Erdfelt <jerdfelt@valinux.com>
   * (C) 2001 NeilBrown <neilb@cse.unsw.edu.au>
   *
   * This driver for the Micro Memory PCI Memory Module with Battery Backup
   * is Copyright Micro Memory Inc 2001-2002.  All rights reserved.
   *
   * This driver is released to the public under the terms of the
   *  GNU GENERAL PUBLIC LICENSE version 2
   * See the file COPYING for details.
   *
   * This driver provides a standard block device interface for Micro Memory(tm)
   * PCI based RAM boards.
   * 10/05/01: Phap Nguyen - Rebuilt the driver
   * 10/22/01: Phap Nguyen - v2.1 Added disk partitioning
   * 29oct2001:NeilBrown   - Use make_request_fn instead of request_fn
   *                       - use stand disk partitioning (so fdisk works).
   * 08nov2001:NeilBrown	 - change driver name from "mm" to "umem"
   *			 - incorporate into main kernel
   * 08apr2002:NeilBrown   - Move some of interrupt handle to tasklet
   *			 - use spin_lock_bh instead of _irq
   *			 - Never block on make_request.  queue
   *			   bh's instead.
   *			 - unregister umem from devfs at mod unload
   *			 - Change version to 2.3
   * 07Nov2001:Phap Nguyen - Select pci read command: 06, 12, 15 (Decimal)
   * 07Jan2002: P. Nguyen  - Used PCI Memory Write & Invalidate for DMA
   * 15May2002:NeilBrown   - convert to bio for 2.5
   * 17May2002:NeilBrown   - remove init_mem initialisation.  Instead detect
   *			 - a sequence of writes that cover the card, and
   *			 - set initialised bit then.
   */

  #undef DEBUG	/* #define DEBUG if you want debugging info (pr_debug) */

  #include <linux/fs.h>
  #include <linux/bio.h>
  #include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/mman.h>

  #include <linux/gfp.h>

  #include <linux/ioctl.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>

  #include <linux/timer.h>
  #include <linux/pci.h>

  #include <linux/dma-mapping.h>

  
  #include <linux/fcntl.h>        /* O_ACCMODE */
  #include <linux/hdreg.h>  /* HDIO_GETGEO */

  #include "umem.h"

  
  #include <asm/uaccess.h>
  #include <asm/io.h>

  #define MM_MAXCARDS 4
  #define MM_RAHEAD 2      /* two sectors */
  #define MM_BLKSIZE 1024  /* 1k blocks */
  #define MM_HARDSECT 512  /* 512-byte hardware sectors */
  #define MM_SHIFT 6       /* max 64 partitions on 4 cards  */
  
  /*
   * Version Information
   */

  #define DRIVER_NAME	"umem"
  #define DRIVER_VERSION	"v2.3"
  #define DRIVER_AUTHOR	"San Mehat, Johannes Erdfelt, NeilBrown"
  #define DRIVER_DESC	"Micro Memory(tm) PCI memory board block driver"

  
  static int debug;
  /* #define HW_TRACE(x)     writeb(x,cards[0].csr_remap + MEMCTRLSTATUS_MAGIC) */
  #define HW_TRACE(x)
  
  #define DEBUG_LED_ON_TRANSFER	0x01
  #define DEBUG_BATTERY_POLLING	0x02
  
  module_param(debug, int, 0644);
  MODULE_PARM_DESC(debug, "Debug bitmask");
  
  static int pci_read_cmd = 0x0C;		/* Read Multiple */
  module_param(pci_read_cmd, int, 0);
  MODULE_PARM_DESC(pci_read_cmd, "PCI read command");
  
  static int pci_write_cmd = 0x0F;	/* Write and Invalidate */
  module_param(pci_write_cmd, int, 0);
  MODULE_PARM_DESC(pci_write_cmd, "PCI write command");
  
  static int pci_cmds;
  
  static int major_nr;
  
  #include <linux/blkdev.h>
  #include <linux/blkpg.h>
  
  struct cardinfo {

  	struct pci_dev	*dev;

  	unsigned char	__iomem *csr_remap;

  	unsigned int	mm_size;  /* size in kbytes */
  
  	unsigned int	init_size; /* initial segment, in sectors,
  				    * that we know to
  				    * have been written
  				    */
  	struct bio	*bio, *currentbio, **biotail;

  	int		current_idx;
  	sector_t	current_sector;

  	struct request_queue *queue;

  
  	struct mm_page {
  		dma_addr_t		page_dma;
  		struct mm_dma_desc	*desc;
  		int	 		cnt, headcnt;
  		struct bio		*bio, **biotail;

  		int			idx;

  	} mm_pages[2];
  #define DESC_PER_PAGE ((PAGE_SIZE*2)/sizeof(struct mm_dma_desc))
  
  	int  Active, Ready;
  
  	struct tasklet_struct	tasklet;
  	unsigned int dma_status;
  
  	struct {
  		int		good;
  		int		warned;
  		unsigned long	last_change;
  	} battery[2];
  
  	spinlock_t 	lock;
  	int		check_batteries;
  
  	int		flags;
  };
  
  static struct cardinfo cards[MM_MAXCARDS];

  static struct timer_list battery_timer;

  static int num_cards;

  
  static struct gendisk *mm_gendisk[MM_MAXCARDS];
  
  static void check_batteries(struct cardinfo *card);

  static int get_userbit(struct cardinfo *card, int bit)
  {
  	unsigned char led;
  
  	led = readb(card->csr_remap + MEMCTRLCMD_LEDCTRL);
  	return led & bit;
  }

  static int set_userbit(struct cardinfo *card, int bit, unsigned char state)
  {
  	unsigned char led;
  
  	led = readb(card->csr_remap + MEMCTRLCMD_LEDCTRL);
  	if (state)
  		led |= bit;
  	else
  		led &= ~bit;
  	writeb(led, card->csr_remap + MEMCTRLCMD_LEDCTRL);
  
  	return 0;
  }

  /*
   * NOTE: For the power LED, use the LED_POWER_* macros since they differ
   */
  static void set_led(struct cardinfo *card, int shift, unsigned char state)
  {
  	unsigned char led;
  
  	led = readb(card->csr_remap + MEMCTRLCMD_LEDCTRL);
  	if (state == LED_FLIP)
  		led ^= (1<<shift);
  	else {
  		led &= ~(0x03 << shift);
  		led |= (state << shift);
  	}
  	writeb(led, card->csr_remap + MEMCTRLCMD_LEDCTRL);
  
  }
  
  #ifdef MM_DIAG

  static void dump_regs(struct cardinfo *card)
  {
  	unsigned char *p;
  	int i, i1;
  
  	p = card->csr_remap;
  	for (i = 0; i < 8; i++) {
  		printk(KERN_DEBUG "%p   ", p);
  
  		for (i1 = 0; i1 < 16; i1++)
  			printk("%02x ", *p++);
  
  		printk("
  ");
  	}
  }
  #endif

  static void dump_dmastat(struct cardinfo *card, unsigned int dmastat)
  {

  	dev_printk(KERN_DEBUG, &card->dev->dev, "DMAstat - ");

  	if (dmastat & DMASCR_ANY_ERR)

  		printk(KERN_CONT "ANY_ERR ");

  	if (dmastat & DMASCR_MBE_ERR)

  		printk(KERN_CONT "MBE_ERR ");

  	if (dmastat & DMASCR_PARITY_ERR_REP)

  		printk(KERN_CONT "PARITY_ERR_REP ");

  	if (dmastat & DMASCR_PARITY_ERR_DET)

  		printk(KERN_CONT "PARITY_ERR_DET ");

  	if (dmastat & DMASCR_SYSTEM_ERR_SIG)

  		printk(KERN_CONT "SYSTEM_ERR_SIG ");

  	if (dmastat & DMASCR_TARGET_ABT)

  		printk(KERN_CONT "TARGET_ABT ");

  	if (dmastat & DMASCR_MASTER_ABT)

  		printk(KERN_CONT "MASTER_ABT ");

  	if (dmastat & DMASCR_CHAIN_COMPLETE)

  		printk(KERN_CONT "CHAIN_COMPLETE ");

  	if (dmastat & DMASCR_DMA_COMPLETE)

  		printk(KERN_CONT "DMA_COMPLETE ");

  	printk("
  ");
  }
  
  /*
   * Theory of request handling
   *
   * Each bio is assigned to one mm_dma_desc - which may not be enough FIXME
   * We have two pages of mm_dma_desc, holding about 64 descriptors
   * each.  These are allocated at init time.
   * One page is "Ready" and is either full, or can have request added.
   * The other page might be "Active", which DMA is happening on it.
   *
   * Whenever IO on the active page completes, the Ready page is activated
   * and the ex-Active page is clean out and made Ready.

   * Otherwise the Ready page is only activated when it becomes full.

   *
   * If a request arrives while both pages a full, it is queued, and b_rdev is
   * overloaded to record whether it was a read or a write.
   *
   * The interrupt handler only polls the device to clear the interrupt.
   * The processing of the result is done in a tasklet.
   */
  
  static void mm_start_io(struct cardinfo *card)
  {
  	/* we have the lock, we know there is
  	 * no IO active, and we know that card->Active
  	 * is set
  	 */
  	struct mm_dma_desc *desc;
  	struct mm_page *page;
  	int offset;
  
  	/* make the last descriptor end the chain */
  	page = &card->mm_pages[card->Active];

  	pr_debug("start_io: %d %d->%d
  ",
  		card->Active, page->headcnt, page->cnt - 1);

  	desc = &page->desc[page->cnt-1];
  
  	desc->control_bits |= cpu_to_le32(DMASCR_CHAIN_COMP_EN);
  	desc->control_bits &= ~cpu_to_le32(DMASCR_CHAIN_EN);
  	desc->sem_control_bits = desc->control_bits;

  	if (debug & DEBUG_LED_ON_TRANSFER)
  		set_led(card, LED_REMOVE, LED_ON);
  
  	desc = &page->desc[page->headcnt];
  	writel(0, card->csr_remap + DMA_PCI_ADDR);
  	writel(0, card->csr_remap + DMA_PCI_ADDR + 4);
  
  	writel(0, card->csr_remap + DMA_LOCAL_ADDR);
  	writel(0, card->csr_remap + DMA_LOCAL_ADDR + 4);
  
  	writel(0, card->csr_remap + DMA_TRANSFER_SIZE);
  	writel(0, card->csr_remap + DMA_TRANSFER_SIZE + 4);
  
  	writel(0, card->csr_remap + DMA_SEMAPHORE_ADDR);
  	writel(0, card->csr_remap + DMA_SEMAPHORE_ADDR + 4);

  	offset = ((char *)desc) - ((char *)page->desc);
  	writel(cpu_to_le32((page->page_dma+offset) & 0xffffffff),

  	       card->csr_remap + DMA_DESCRIPTOR_ADDR);
  	/* Force the value to u64 before shifting otherwise >> 32 is undefined C
  	 * and on some ports will do nothing ! */
  	writel(cpu_to_le32(((u64)page->page_dma)>>32),
  	       card->csr_remap + DMA_DESCRIPTOR_ADDR + 4);
  
  	/* Go, go, go */
  	writel(cpu_to_le32(DMASCR_GO | DMASCR_CHAIN_EN | pci_cmds),
  	       card->csr_remap + DMA_STATUS_CTRL);
  }
  
  static int add_bio(struct cardinfo *card);
  
  static void activate(struct cardinfo *card)
  {

  	/* if No page is Active, and Ready is

  	 * not empty, then switch Ready page
  	 * to active and start IO.
  	 * Then add any bh's that are available to Ready
  	 */
  
  	do {
  		while (add_bio(card))
  			;
  
  		if (card->Active == -1 &&
  		    card->mm_pages[card->Ready].cnt > 0) {
  			card->Active = card->Ready;
  			card->Ready = 1-card->Ready;
  			mm_start_io(card);
  		}
  
  	} while (card->Active == -1 && add_bio(card));
  }
  
  static inline void reset_page(struct mm_page *page)
  {
  	page->cnt = 0;
  	page->headcnt = 0;
  	page->bio = NULL;

  	page->biotail = &page->bio;

  }

  /*

   * If there is room on Ready page, take
   * one bh off list and add it.
   * return 1 if there was room, else 0.
   */
  static int add_bio(struct cardinfo *card)
  {
  	struct mm_page *p;
  	struct mm_dma_desc *desc;
  	dma_addr_t dma_handle;
  	int offset;
  	struct bio *bio;

  	struct bio_vec *vec;
  	int idx;

  	int rw;
  	int len;
  
  	bio = card->currentbio;
  	if (!bio && card->bio) {
  		card->currentbio = card->bio;

  		card->current_idx = card->bio->bi_idx;
  		card->current_sector = card->bio->bi_sector;

  		card->bio = card->bio->bi_next;
  		if (card->bio == NULL)
  			card->biotail = &card->bio;
  		card->currentbio->bi_next = NULL;
  		return 1;
  	}
  	if (!bio)
  		return 0;

  	idx = card->current_idx;

  
  	rw = bio_rw(bio);
  	if (card->mm_pages[card->Ready].cnt >= DESC_PER_PAGE)
  		return 0;

  	vec = bio_iovec_idx(bio, idx);
  	len = vec->bv_len;
  	dma_handle = pci_map_page(card->dev,
  				  vec->bv_page,
  				  vec->bv_offset,

  				  len,

  				  (rw == READ) ?

  				  PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE);
  
  	p = &card->mm_pages[card->Ready];
  	desc = &p->desc[p->cnt];
  	p->cnt++;

  	if (p->bio == NULL)
  		p->idx = idx;

  	if ((p->biotail) != &bio->bi_next) {
  		*(p->biotail) = bio;
  		p->biotail = &(bio->bi_next);
  		bio->bi_next = NULL;
  	}
  
  	desc->data_dma_handle = dma_handle;
  
  	desc->pci_addr = cpu_to_le64((u64)desc->data_dma_handle);

  	desc->local_addr = cpu_to_le64(card->current_sector << 9);

  	desc->transfer_size = cpu_to_le32(len);

  	offset = (((char *)&desc->sem_control_bits) - ((char *)p->desc));

  	desc->sem_addr = cpu_to_le64((u64)(p->page_dma+offset));
  	desc->zero1 = desc->zero2 = 0;

  	offset = (((char *)(desc+1)) - ((char *)p->desc));

  	desc->next_desc_addr = cpu_to_le64(p->page_dma+offset);
  	desc->control_bits = cpu_to_le32(DMASCR_GO|DMASCR_ERR_INT_EN|
  					 DMASCR_PARITY_INT_EN|
  					 DMASCR_CHAIN_EN |
  					 DMASCR_SEM_EN |
  					 pci_cmds);
  	if (rw == WRITE)
  		desc->control_bits |= cpu_to_le32(DMASCR_TRANSFER_READ);
  	desc->sem_control_bits = desc->control_bits;

  	card->current_sector += (len >> 9);
  	idx++;
  	card->current_idx = idx;
  	if (idx >= bio->bi_vcnt)

  		card->currentbio = NULL;
  
  	return 1;
  }
  
  static void process_page(unsigned long data)
  {
  	/* check if any of the requests in the page are DMA_COMPLETE,
  	 * and deal with them appropriately.
  	 * If we find a descriptor without DMA_COMPLETE in the semaphore, then

  	 * dma must have hit an error on that descriptor, so use dma_status
  	 * instead and assume that all following descriptors must be re-tried.

  	 */
  	struct mm_page *page;

  	struct bio *return_bio = NULL;

  	struct cardinfo *card = (struct cardinfo *)data;
  	unsigned int dma_status = card->dma_status;
  
  	spin_lock_bh(&card->lock);
  	if (card->Active < 0)
  		goto out_unlock;
  	page = &card->mm_pages[card->Active];

  	while (page->headcnt < page->cnt) {
  		struct bio *bio = page->bio;
  		struct mm_dma_desc *desc = &page->desc[page->headcnt];
  		int control = le32_to_cpu(desc->sem_control_bits);

  		int last = 0;

  		int idx;
  
  		if (!(control & DMASCR_DMA_COMPLETE)) {
  			control = dma_status;

  			last = 1;

  		}
  		page->headcnt++;

  		idx = page->idx;
  		page->idx++;
  		if (page->idx >= bio->bi_vcnt) {

  			page->bio = bio->bi_next;

  			if (page->bio)
  				page->idx = page->bio->bi_idx;

  		}

  		pci_unmap_page(card->dev, desc->data_dma_handle,

  			       bio_iovec_idx(bio, idx)->bv_len,
  				 (control & DMASCR_TRANSFER_READ) ?

  				PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
  		if (control & DMASCR_HARD_ERROR) {
  			/* error */
  			clear_bit(BIO_UPTODATE, &bio->bi_flags);

  			dev_printk(KERN_WARNING, &card->dev->dev,
  				"I/O error on sector %d/%d
  ",
  				le32_to_cpu(desc->local_addr)>>9,
  				le32_to_cpu(desc->transfer_size));

  			dump_dmastat(card, control);

  		} else if ((bio->bi_rw & REQ_WRITE) &&

  			   le32_to_cpu(desc->local_addr) >> 9 ==
  				card->init_size) {
  			card->init_size += le32_to_cpu(desc->transfer_size) >> 9;
  			if (card->init_size >> 1 >= card->mm_size) {

  				dev_printk(KERN_INFO, &card->dev->dev,
  					"memory now initialised
  ");

  				set_userbit(card, MEMORY_INITIALIZED, 1);
  			}
  		}
  		if (bio != page->bio) {
  			bio->bi_next = return_bio;
  			return_bio = bio;
  		}

  		if (last)
  			break;

  	}
  
  	if (debug & DEBUG_LED_ON_TRANSFER)
  		set_led(card, LED_REMOVE, LED_OFF);
  
  	if (card->check_batteries) {
  		card->check_batteries = 0;
  		check_batteries(card);
  	}
  	if (page->headcnt >= page->cnt) {
  		reset_page(page);
  		card->Active = -1;
  		activate(card);
  	} else {
  		/* haven't finished with this one yet */

  		pr_debug("do some more
  ");

  		mm_start_io(card);
  	}
   out_unlock:
  	spin_unlock_bh(&card->lock);

  	while (return_bio) {

  		struct bio *bio = return_bio;
  
  		return_bio = bio->bi_next;
  		bio->bi_next = NULL;

  		bio_endio(bio, 0);

  	}
  }

  static void mm_make_request(struct request_queue *q, struct bio *bio)

  {
  	struct cardinfo *card = q->queuedata;

  	pr_debug("mm_make_request %llu %u
  ",
  		 (unsigned long long)bio->bi_sector, bio->bi_size);

  	spin_lock_irq(&card->lock);
  	*card->biotail = bio;
  	bio->bi_next = NULL;
  	card->biotail = &bio->bi_next;

  	spin_unlock_irq(&card->lock);

  	return;

  }

  static irqreturn_t mm_interrupt(int irq, void *__card)

  {
  	struct cardinfo *card = (struct cardinfo *) __card;
  	unsigned int dma_status;
  	unsigned short cfg_status;
  
  HW_TRACE(0x30);
  
  	dma_status = le32_to_cpu(readl(card->csr_remap + DMA_STATUS_CTRL));
  
  	if (!(dma_status & (DMASCR_ERROR_MASK | DMASCR_CHAIN_COMPLETE))) {
  		/* interrupt wasn't for me ... */
  		return IRQ_NONE;

  	}

  
  	/* clear COMPLETION interrupts */
  	if (card->flags & UM_FLAG_NO_BYTE_STATUS)
  		writel(cpu_to_le32(DMASCR_DMA_COMPLETE|DMASCR_CHAIN_COMPLETE),

  		       card->csr_remap + DMA_STATUS_CTRL);

  	else
  		writeb((DMASCR_DMA_COMPLETE|DMASCR_CHAIN_COMPLETE) >> 16,

  		       card->csr_remap + DMA_STATUS_CTRL + 2);

  	/* log errors and clear interrupt status */
  	if (dma_status & DMASCR_ANY_ERR) {
  		unsigned int	data_log1, data_log2;
  		unsigned int	addr_log1, addr_log2;
  		unsigned char	stat, count, syndrome, check;
  
  		stat = readb(card->csr_remap + MEMCTRLCMD_ERRSTATUS);

  		data_log1 = le32_to_cpu(readl(card->csr_remap +
  						ERROR_DATA_LOG));
  		data_log2 = le32_to_cpu(readl(card->csr_remap +
  						ERROR_DATA_LOG + 4));
  		addr_log1 = le32_to_cpu(readl(card->csr_remap +
  						ERROR_ADDR_LOG));

  		addr_log2 = readb(card->csr_remap + ERROR_ADDR_LOG + 4);
  
  		count = readb(card->csr_remap + ERROR_COUNT);
  		syndrome = readb(card->csr_remap + ERROR_SYNDROME);
  		check = readb(card->csr_remap + ERROR_CHECK);
  
  		dump_dmastat(card, dma_status);
  
  		if (stat & 0x01)

  			dev_printk(KERN_ERR, &card->dev->dev,
  				"Memory access error detected (err count %d)
  ",
  				count);

  		if (stat & 0x02)

  			dev_printk(KERN_ERR, &card->dev->dev,
  				"Multi-bit EDC error
  ");

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"Fault Address 0x%02x%08x, Fault Data 0x%08x%08x
  ",
  			addr_log2, addr_log1, data_log2, data_log1);
  		dev_printk(KERN_ERR, &card->dev->dev,
  			"Fault Check 0x%02x, Fault Syndrome 0x%02x
  ",
  			check, syndrome);

  
  		writeb(0, card->csr_remap + ERROR_COUNT);
  	}
  
  	if (dma_status & DMASCR_PARITY_ERR_REP) {

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"PARITY ERROR REPORTED
  ");

  		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
  		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
  	}
  
  	if (dma_status & DMASCR_PARITY_ERR_DET) {

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"PARITY ERROR DETECTED
  ");

  		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
  		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
  	}
  
  	if (dma_status & DMASCR_SYSTEM_ERR_SIG) {

  		dev_printk(KERN_ERR, &card->dev->dev, "SYSTEM ERROR
  ");

  		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
  		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
  	}
  
  	if (dma_status & DMASCR_TARGET_ABT) {

  		dev_printk(KERN_ERR, &card->dev->dev, "TARGET ABORT
  ");

  		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
  		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
  	}
  
  	if (dma_status & DMASCR_MASTER_ABT) {

  		dev_printk(KERN_ERR, &card->dev->dev, "MASTER ABORT
  ");

  		pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
  		pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
  	}
  
  	/* and process the DMA descriptors */
  	card->dma_status = dma_status;
  	tasklet_schedule(&card->tasklet);
  
  HW_TRACE(0x36);

  	return IRQ_HANDLED;

  }

  /*
   * If both batteries are good, no LED
   * If either battery has been warned, solid LED
   * If both batteries are bad, flash the LED quickly
   * If either battery is bad, flash the LED semi quickly
   */
  static void set_fault_to_battery_status(struct cardinfo *card)
  {
  	if (card->battery[0].good && card->battery[1].good)
  		set_led(card, LED_FAULT, LED_OFF);
  	else if (card->battery[0].warned || card->battery[1].warned)
  		set_led(card, LED_FAULT, LED_ON);
  	else if (!card->battery[0].good && !card->battery[1].good)
  		set_led(card, LED_FAULT, LED_FLASH_7_0);
  	else
  		set_led(card, LED_FAULT, LED_FLASH_3_5);
  }
  
  static void init_battery_timer(void);

  static int check_battery(struct cardinfo *card, int battery, int status)
  {
  	if (status != card->battery[battery].good) {
  		card->battery[battery].good = !card->battery[battery].good;
  		card->battery[battery].last_change = jiffies;
  
  		if (card->battery[battery].good) {

  			dev_printk(KERN_ERR, &card->dev->dev,
  				"Battery %d now good
  ", battery + 1);

  			card->battery[battery].warned = 0;
  		} else

  			dev_printk(KERN_ERR, &card->dev->dev,
  				"Battery %d now FAILED
  ", battery + 1);

  
  		return 1;
  	} else if (!card->battery[battery].good &&
  		   !card->battery[battery].warned &&
  		   time_after_eq(jiffies, card->battery[battery].last_change +
  				 (HZ * 60 * 60 * 5))) {

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"Battery %d still FAILED after 5 hours
  ", battery + 1);

  		card->battery[battery].warned = 1;
  
  		return 1;
  	}
  
  	return 0;
  }

  static void check_batteries(struct cardinfo *card)
  {
  	/* NOTE: this must *never* be called while the card
  	 * is doing (bus-to-card) DMA, or you will need the
  	 * reset switch
  	 */
  	unsigned char status;
  	int ret1, ret2;
  
  	status = readb(card->csr_remap + MEMCTRLSTATUS_BATTERY);
  	if (debug & DEBUG_BATTERY_POLLING)

  		dev_printk(KERN_DEBUG, &card->dev->dev,
  			"checking battery status, 1 = %s, 2 = %s
  ",

  		       (status & BATTERY_1_FAILURE) ? "FAILURE" : "OK",
  		       (status & BATTERY_2_FAILURE) ? "FAILURE" : "OK");
  
  	ret1 = check_battery(card, 0, !(status & BATTERY_1_FAILURE));
  	ret2 = check_battery(card, 1, !(status & BATTERY_2_FAILURE));
  
  	if (ret1 || ret2)
  		set_fault_to_battery_status(card);
  }
  
  static void check_all_batteries(unsigned long ptr)
  {
  	int i;

  	for (i = 0; i < num_cards; i++)

  		if (!(cards[i].flags & UM_FLAG_NO_BATT)) {
  			struct cardinfo *card = &cards[i];
  			spin_lock_bh(&card->lock);
  			if (card->Active >= 0)
  				card->check_batteries = 1;
  			else
  				check_batteries(card);
  			spin_unlock_bh(&card->lock);
  		}
  
  	init_battery_timer();
  }

  static void init_battery_timer(void)
  {
  	init_timer(&battery_timer);
  	battery_timer.function = check_all_batteries;
  	battery_timer.expires = jiffies + (HZ * 60);
  	add_timer(&battery_timer);
  }

  static void del_battery_timer(void)
  {
  	del_timer(&battery_timer);
  }

  /*
   * Note no locks taken out here.  In a worst case scenario, we could drop
   * a chunk of system memory.  But that should never happen, since validation
   * happens at open or mount time, when locks are held.
   *
   *	That's crap, since doing that while some partitions are opened
   * or mounted will give you really nasty results.
   */
  static int mm_revalidate(struct gendisk *disk)
  {
  	struct cardinfo *card = disk->private_data;
  	set_capacity(disk, card->mm_size << 1);
  	return 0;
  }

  
  static int mm_getgeo(struct block_device *bdev, struct hd_geometry *geo)

  {

  	struct cardinfo *card = bdev->bd_disk->private_data;
  	int size = card->mm_size * (1024 / MM_HARDSECT);

  	/*
  	 * get geometry: we have to fake one...  trim the size to a
  	 * multiple of 2048 (1M): tell we have 32 sectors, 64 heads,
  	 * whatever cylinders.
  	 */
  	geo->heads     = 64;
  	geo->sectors   = 32;
  	geo->cylinders = size / (geo->heads * geo->sectors);
  	return 0;

  }

  static const struct block_device_operations mm_fops = {

  	.owner		= THIS_MODULE,

  	.getgeo		= mm_getgeo,

  	.revalidate_disk = mm_revalidate,

  };

  
  static int __devinit mm_pci_probe(struct pci_dev *dev,
  				const struct pci_device_id *id)

  {
  	int ret = -ENODEV;
  	struct cardinfo *card = &cards[num_cards];
  	unsigned char	mem_present;
  	unsigned char	batt_status;
  	unsigned int	saved_bar, data;

  	unsigned long	csr_base;
  	unsigned long	csr_len;

  	int		magic_number;

  	static int	printed_version;
  
  	if (!printed_version++)
  		printk(KERN_INFO DRIVER_VERSION " : " DRIVER_DESC "
  ");

  	ret = pci_enable_device(dev);
  	if (ret)
  		return ret;

  
  	pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0xF8);
  	pci_set_master(dev);
  
  	card->dev         = dev;

  	csr_base = pci_resource_start(dev, 0);
  	csr_len  = pci_resource_len(dev, 0);
  	if (!csr_base || !csr_len)
  		return -ENODEV;

  	dev_printk(KERN_INFO, &dev->dev,

  	  "Micro Memory(tm) controller found (PCI Mem Module (Battery Backup))
  ");

  	if (pci_set_dma_mask(dev, DMA_BIT_MASK(64)) &&

  	    pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {

  		dev_printk(KERN_WARNING, &dev->dev, "NO suitable DMA found
  ");

  		return  -ENOMEM;
  	}

  
  	ret = pci_request_regions(dev, DRIVER_NAME);
  	if (ret) {

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"Unable to request memory region
  ");

  		goto failed_req_csr;
  	}

  	card->csr_remap = ioremap_nocache(csr_base, csr_len);

  	if (!card->csr_remap) {

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"Unable to remap memory region
  ");

  		ret = -ENOMEM;
  
  		goto failed_remap_csr;
  	}

  	dev_printk(KERN_INFO, &card->dev->dev,
  		"CSR 0x%08lx -> 0x%p (0x%lx)
  ",

  	       csr_base, card->csr_remap, csr_len);

  	switch (card->dev->device) {

  	case 0x5415:
  		card->flags |= UM_FLAG_NO_BYTE_STATUS | UM_FLAG_NO_BATTREG;
  		magic_number = 0x59;
  		break;
  
  	case 0x5425:
  		card->flags |= UM_FLAG_NO_BYTE_STATUS;
  		magic_number = 0x5C;
  		break;
  
  	case 0x6155:

  		card->flags |= UM_FLAG_NO_BYTE_STATUS |
  				UM_FLAG_NO_BATTREG | UM_FLAG_NO_BATT;

  		magic_number = 0x99;
  		break;
  
  	default:
  		magic_number = 0x100;
  		break;
  	}
  
  	if (readb(card->csr_remap + MEMCTRLSTATUS_MAGIC) != magic_number) {

  		dev_printk(KERN_ERR, &card->dev->dev, "Magic number invalid
  ");

  		ret = -ENOMEM;
  		goto failed_magic;
  	}
  
  	card->mm_pages[0].desc = pci_alloc_consistent(card->dev,

  						PAGE_SIZE * 2,
  						&card->mm_pages[0].page_dma);

  	card->mm_pages[1].desc = pci_alloc_consistent(card->dev,

  						PAGE_SIZE * 2,
  						&card->mm_pages[1].page_dma);

  	if (card->mm_pages[0].desc == NULL ||
  	    card->mm_pages[1].desc == NULL) {

  		dev_printk(KERN_ERR, &card->dev->dev, "alloc failed
  ");

  		goto failed_alloc;
  	}
  	reset_page(&card->mm_pages[0]);
  	reset_page(&card->mm_pages[1]);
  	card->Ready = 0;	/* page 0 is ready */
  	card->Active = -1;	/* no page is active */
  	card->bio = NULL;
  	card->biotail = &card->bio;
  
  	card->queue = blk_alloc_queue(GFP_KERNEL);
  	if (!card->queue)
  		goto failed_alloc;
  
  	blk_queue_make_request(card->queue, mm_make_request);

  	card->queue->queue_lock = &card->lock;

  	card->queue->queuedata = card;

  
  	tasklet_init(&card->tasklet, process_page, (unsigned long)card);
  
  	card->check_batteries = 0;

  	mem_present = readb(card->csr_remap + MEMCTRLSTATUS_MEMORY);
  	switch (mem_present) {
  	case MEM_128_MB:
  		card->mm_size = 1024 * 128;
  		break;
  	case MEM_256_MB:
  		card->mm_size = 1024 * 256;
  		break;
  	case MEM_512_MB:
  		card->mm_size = 1024 * 512;
  		break;
  	case MEM_1_GB:
  		card->mm_size = 1024 * 1024;
  		break;
  	case MEM_2_GB:
  		card->mm_size = 1024 * 2048;
  		break;
  	default:
  		card->mm_size = 0;
  		break;
  	}
  
  	/* Clear the LED's we control */
  	set_led(card, LED_REMOVE, LED_OFF);
  	set_led(card, LED_FAULT, LED_OFF);
  
  	batt_status = readb(card->csr_remap + MEMCTRLSTATUS_BATTERY);
  
  	card->battery[0].good = !(batt_status & BATTERY_1_FAILURE);
  	card->battery[1].good = !(batt_status & BATTERY_2_FAILURE);
  	card->battery[0].last_change = card->battery[1].last_change = jiffies;

  	if (card->flags & UM_FLAG_NO_BATT)

  		dev_printk(KERN_INFO, &card->dev->dev,
  			"Size %d KB
  ", card->mm_size);

  	else {

  		dev_printk(KERN_INFO, &card->dev->dev,
  			"Size %d KB, Battery 1 %s (%s), Battery 2 %s (%s)
  ",
  		       card->mm_size,

  		       batt_status & BATTERY_1_DISABLED ? "Disabled" : "Enabled",

  		       card->battery[0].good ? "OK" : "FAILURE",

  		       batt_status & BATTERY_2_DISABLED ? "Disabled" : "Enabled",

  		       card->battery[1].good ? "OK" : "FAILURE");
  
  		set_fault_to_battery_status(card);
  	}
  
  	pci_read_config_dword(dev, PCI_BASE_ADDRESS_1, &saved_bar);
  	data = 0xffffffff;
  	pci_write_config_dword(dev, PCI_BASE_ADDRESS_1, data);
  	pci_read_config_dword(dev, PCI_BASE_ADDRESS_1, &data);
  	pci_write_config_dword(dev, PCI_BASE_ADDRESS_1, saved_bar);
  	data &= 0xfffffff0;
  	data = ~data;
  	data += 1;

  	if (request_irq(dev->irq, mm_interrupt, IRQF_SHARED, DRIVER_NAME,
  			card)) {

  		dev_printk(KERN_ERR, &card->dev->dev,
  			"Unable to allocate IRQ
  ");

  		ret = -ENODEV;

  		goto failed_req_irq;
  	}

  	dev_printk(KERN_INFO, &card->dev->dev,

  		"Window size %d bytes, IRQ %d
  ", data, dev->irq);

  	spin_lock_init(&card->lock);

  
  	pci_set_drvdata(dev, card);
  
  	if (pci_write_cmd != 0x0F) 	/* If not Memory Write & Invalidate */
  		pci_write_cmd = 0x07;	/* then Memory Write command */
  
  	if (pci_write_cmd & 0x08) { /* use Memory Write and Invalidate */
  		unsigned short cfg_command;
  		pci_read_config_word(dev, PCI_COMMAND, &cfg_command);
  		cfg_command |= 0x10; /* Memory Write & Invalidate Enable */
  		pci_write_config_word(dev, PCI_COMMAND, cfg_command);
  	}
  	pci_cmds = (pci_read_cmd << 28) | (pci_write_cmd << 24);
  
  	num_cards++;
  
  	if (!get_userbit(card, MEMORY_INITIALIZED)) {

  		dev_printk(KERN_INFO, &card->dev->dev,

  		  "memory NOT initialized. Consider over-writing whole device.
  ");

  		card->init_size = 0;
  	} else {

  		dev_printk(KERN_INFO, &card->dev->dev,
  			"memory already initialized
  ");

  		card->init_size = card->mm_size;
  	}
  
  	/* Enable ECC */
  	writeb(EDC_STORE_CORRECT, card->csr_remap + MEMCTRLCMD_ERRCTRL);
  
  	return 0;
  
   failed_req_irq:
   failed_alloc:
  	if (card->mm_pages[0].desc)
  		pci_free_consistent(card->dev, PAGE_SIZE*2,
  				    card->mm_pages[0].desc,
  				    card->mm_pages[0].page_dma);
  	if (card->mm_pages[1].desc)
  		pci_free_consistent(card->dev, PAGE_SIZE*2,
  				    card->mm_pages[1].desc,
  				    card->mm_pages[1].page_dma);
   failed_magic:

  	iounmap(card->csr_remap);
   failed_remap_csr:

  	pci_release_regions(dev);

   failed_req_csr:
  
  	return ret;
  }

  static void mm_pci_remove(struct pci_dev *dev)
  {
  	struct cardinfo *card = pci_get_drvdata(dev);
  
  	tasklet_kill(&card->tasklet);

  	free_irq(dev->irq, card);

  	iounmap(card->csr_remap);

  
  	if (card->mm_pages[0].desc)
  		pci_free_consistent(card->dev, PAGE_SIZE*2,
  				    card->mm_pages[0].desc,
  				    card->mm_pages[0].page_dma);
  	if (card->mm_pages[1].desc)
  		pci_free_consistent(card->dev, PAGE_SIZE*2,
  				    card->mm_pages[1].desc,
  				    card->mm_pages[1].page_dma);

  	blk_cleanup_queue(card->queue);

  
  	pci_release_regions(dev);
  	pci_disable_device(dev);

  }

  static const struct pci_device_id mm_pci_ids[] = {

      {PCI_DEVICE(PCI_VENDOR_ID_MICRO_MEMORY, PCI_DEVICE_ID_MICRO_MEMORY_5415CN)},
      {PCI_DEVICE(PCI_VENDOR_ID_MICRO_MEMORY, PCI_DEVICE_ID_MICRO_MEMORY_5425CN)},
      {PCI_DEVICE(PCI_VENDOR_ID_MICRO_MEMORY, PCI_DEVICE_ID_MICRO_MEMORY_6155)},

      {

  	.vendor	=	0x8086,
  	.device	=	0xB555,

  	.subvendor =	0x1332,
  	.subdevice =	0x5460,
  	.class =	0x050000,
  	.class_mask =	0,

      }, { /* end: all zeroes */ }

  };
  
  MODULE_DEVICE_TABLE(pci, mm_pci_ids);
  
  static struct pci_driver mm_pci_driver = {

  	.name		= DRIVER_NAME,
  	.id_table	= mm_pci_ids,
  	.probe		= mm_pci_probe,
  	.remove		= mm_pci_remove,

  };

  static int __init mm_init(void)
  {
  	int retval, i;
  	int err;

  	retval = pci_register_driver(&mm_pci_driver);

  	if (retval)
  		return -ENOMEM;

  	err = major_nr = register_blkdev(0, DRIVER_NAME);

  	if (err < 0) {
  		pci_unregister_driver(&mm_pci_driver);

  		return -EIO;

  	}

  
  	for (i = 0; i < num_cards; i++) {
  		mm_gendisk[i] = alloc_disk(1 << MM_SHIFT);
  		if (!mm_gendisk[i])
  			goto out;
  	}
  
  	for (i = 0; i < num_cards; i++) {
  		struct gendisk *disk = mm_gendisk[i];
  		sprintf(disk->disk_name, "umem%c", 'a'+i);

  		spin_lock_init(&cards[i].lock);
  		disk->major = major_nr;
  		disk->first_minor  = i << MM_SHIFT;
  		disk->fops = &mm_fops;
  		disk->private_data = &cards[i];
  		disk->queue = cards[i].queue;
  		set_capacity(disk, cards[i].mm_size << 1);
  		add_disk(disk);
  	}
  
  	init_battery_timer();

  	printk(KERN_INFO "MM: desc_per_page = %ld
  ", DESC_PER_PAGE);

  /* printk("mm_init: Done. 10-19-01 9:00
  "); */
  	return 0;
  
  out:

  	pci_unregister_driver(&mm_pci_driver);

  	unregister_blkdev(major_nr, DRIVER_NAME);

  	while (i--)
  		put_disk(mm_gendisk[i]);
  	return -ENOMEM;
  }

  static void __exit mm_cleanup(void)
  {
  	int i;
  
  	del_battery_timer();

  	for (i = 0; i < num_cards ; i++) {

  		del_gendisk(mm_gendisk[i]);
  		put_disk(mm_gendisk[i]);
  	}
  
  	pci_unregister_driver(&mm_pci_driver);

  	unregister_blkdev(major_nr, DRIVER_NAME);

  }
  
  module_init(mm_init);
  module_exit(mm_cleanup);
  
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL");