/*

   * Driver for the HP iLO management processor.

   *
   * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
   *	David Altobelli <david.altobelli@hp.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/module.h>
  #include <linux/fs.h>
  #include <linux/pci.h>

  #include <linux/interrupt.h>

  #include <linux/ioport.h>
  #include <linux/device.h>
  #include <linux/file.h>
  #include <linux/cdev.h>

  #include <linux/sched.h>

  #include <linux/spinlock.h>
  #include <linux/delay.h>
  #include <linux/uaccess.h>
  #include <linux/io.h>

  #include <linux/wait.h>

  #include <linux/poll.h>

  #include <linux/slab.h>

  #include "hpilo.h"
  
  static struct class *ilo_class;
  static unsigned int ilo_major;
  static char ilo_hwdev[MAX_ILO_DEV];
  
  static inline int get_entry_id(int entry)
  {
  	return (entry & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR;
  }
  
  static inline int get_entry_len(int entry)
  {
  	return ((entry & ENTRY_MASK_QWORDS) >> ENTRY_BITPOS_QWORDS) << 3;
  }
  
  static inline int mk_entry(int id, int len)
  {
  	int qlen = len & 7 ? (len >> 3) + 1 : len >> 3;
  	return id << ENTRY_BITPOS_DESCRIPTOR | qlen << ENTRY_BITPOS_QWORDS;
  }
  
  static inline int desc_mem_sz(int nr_entry)
  {
  	return nr_entry << L2_QENTRY_SZ;
  }
  
  /*
   * FIFO queues, shared with hardware.
   *
   * If a queue has empty slots, an entry is added to the queue tail,
   * and that entry is marked as occupied.
   * Entries can be dequeued from the head of the list, when the device
   * has marked the entry as consumed.
   *
   * Returns true on successful queue/dequeue, false on failure.
   */
  static int fifo_enqueue(struct ilo_hwinfo *hw, char *fifobar, int entry)
  {
  	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);

  	unsigned long flags;

  	int ret = 0;

  	spin_lock_irqsave(&hw->fifo_lock, flags);

  	if (!(fifo_q->fifobar[(fifo_q->tail + 1) & fifo_q->imask]
  	      & ENTRY_MASK_O)) {
  		fifo_q->fifobar[fifo_q->tail & fifo_q->imask] |=
  				(entry & ENTRY_MASK_NOSTATE) | fifo_q->merge;
  		fifo_q->tail += 1;
  		ret = 1;
  	}

  	spin_unlock_irqrestore(&hw->fifo_lock, flags);

  
  	return ret;
  }
  
  static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
  {
  	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);

  	unsigned long flags;

  	int ret = 0;
  	u64 c;

  	spin_lock_irqsave(&hw->fifo_lock, flags);

  	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
  	if (c & ENTRY_MASK_C) {
  		if (entry)
  			*entry = c & ENTRY_MASK_NOSTATE;
  
  		fifo_q->fifobar[fifo_q->head & fifo_q->imask] =
  							(c | ENTRY_MASK) + 1;
  		fifo_q->head += 1;
  		ret = 1;
  	}

  	spin_unlock_irqrestore(&hw->fifo_lock, flags);

  
  	return ret;
  }

  static int fifo_check_recv(struct ilo_hwinfo *hw, char *fifobar)
  {
  	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
  	unsigned long flags;
  	int ret = 0;
  	u64 c;
  
  	spin_lock_irqsave(&hw->fifo_lock, flags);
  	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
  	if (c & ENTRY_MASK_C)
  		ret = 1;
  	spin_unlock_irqrestore(&hw->fifo_lock, flags);
  
  	return ret;
  }

  static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
  			   int dir, int id, int len)
  {
  	char *fifobar;
  	int entry;
  
  	if (dir == SENDQ)
  		fifobar = ccb->ccb_u1.send_fifobar;
  	else
  		fifobar = ccb->ccb_u3.recv_fifobar;
  
  	entry = mk_entry(id, len);
  	return fifo_enqueue(hw, fifobar, entry);
  }
  
  static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
  			   int dir, int *id, int *len, void **pkt)
  {
  	char *fifobar, *desc;
  	int entry = 0, pkt_id = 0;
  	int ret;
  
  	if (dir == SENDQ) {
  		fifobar = ccb->ccb_u1.send_fifobar;
  		desc = ccb->ccb_u2.send_desc;
  	} else {
  		fifobar = ccb->ccb_u3.recv_fifobar;
  		desc = ccb->ccb_u4.recv_desc;
  	}
  
  	ret = fifo_dequeue(hw, fifobar, &entry);
  	if (ret) {
  		pkt_id = get_entry_id(entry);
  		if (id)
  			*id = pkt_id;
  		if (len)
  			*len = get_entry_len(entry);
  		if (pkt)
  			*pkt = (void *)(desc + desc_mem_sz(pkt_id));
  	}
  
  	return ret;
  }

  static int ilo_pkt_recv(struct ilo_hwinfo *hw, struct ccb *ccb)
  {
  	char *fifobar = ccb->ccb_u3.recv_fifobar;
  
  	return fifo_check_recv(hw, fifobar);
  }

  static inline void doorbell_set(struct ccb *ccb)
  {
  	iowrite8(1, ccb->ccb_u5.db_base);
  }
  
  static inline void doorbell_clr(struct ccb *ccb)
  {
  	iowrite8(2, ccb->ccb_u5.db_base);
  }

  static inline int ctrl_set(int l2sz, int idxmask, int desclim)
  {
  	int active = 0, go = 1;
  	return l2sz << CTRL_BITPOS_L2SZ |
  	       idxmask << CTRL_BITPOS_FIFOINDEXMASK |
  	       desclim << CTRL_BITPOS_DESCLIMIT |
  	       active << CTRL_BITPOS_A |
  	       go << CTRL_BITPOS_G;
  }

  static void ctrl_setup(struct ccb *ccb, int nr_desc, int l2desc_sz)
  {
  	/* for simplicity, use the same parameters for send and recv ctrls */
  	ccb->send_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
  	ccb->recv_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
  }
  
  static inline int fifo_sz(int nr_entry)
  {
  	/* size of a fifo is determined by the number of entries it contains */
  	return (nr_entry * sizeof(u64)) + FIFOHANDLESIZE;
  }
  
  static void fifo_setup(void *base_addr, int nr_entry)
  {
  	struct fifo *fifo_q = base_addr;
  	int i;
  
  	/* set up an empty fifo */
  	fifo_q->head = 0;
  	fifo_q->tail = 0;
  	fifo_q->reset = 0;
  	fifo_q->nrents = nr_entry;
  	fifo_q->imask = nr_entry - 1;
  	fifo_q->merge = ENTRY_MASK_O;
  
  	for (i = 0; i < nr_entry; i++)
  		fifo_q->fifobar[i] = 0;
  }
  
  static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
  {

  	struct ccb *driver_ccb = &data->driver_ccb;
  	struct ccb __iomem *device_ccb = data->mapped_ccb;

  	int retries;

  	/* complicated dance to tell the hw we are stopping */
  	doorbell_clr(driver_ccb);
  	iowrite32(ioread32(&device_ccb->send_ctrl) & ~(1 << CTRL_BITPOS_G),
  		  &device_ccb->send_ctrl);
  	iowrite32(ioread32(&device_ccb->recv_ctrl) & ~(1 << CTRL_BITPOS_G),
  		  &device_ccb->recv_ctrl);
  
  	/* give iLO some time to process stop request */

  	for (retries = MAX_WAIT; retries > 0; retries--) {

  		doorbell_set(driver_ccb);

  		udelay(WAIT_TIME);

  		if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
  		    &&
  		    !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
  			break;
  	}
  	if (retries == 0)
  		dev_err(&pdev->dev, "Closing, but controller still active
  ");
  
  	/* clear the hw ccb */
  	memset_io(device_ccb, 0, sizeof(struct ccb));
  
  	/* free resources used to back send/recv queues */
  	pci_free_consistent(pdev, data->dma_size, data->dma_va, data->dma_pa);
  }

  static int ilo_ccb_setup(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)

  {

  	char *dma_va;
  	dma_addr_t dma_pa;

  	struct ccb *driver_ccb, *ilo_ccb;

  
  	driver_ccb = &data->driver_ccb;
  	ilo_ccb = &data->ilo_ccb;

  
  	data->dma_size = 2 * fifo_sz(NR_QENTRY) +
  			 2 * desc_mem_sz(NR_QENTRY) +
  			 ILO_START_ALIGN + ILO_CACHE_SZ;

  	data->dma_va = pci_alloc_consistent(hw->ilo_dev, data->dma_size,

  					    &data->dma_pa);
  	if (!data->dma_va)

  		return -ENOMEM;

  
  	dma_va = (char *)data->dma_va;

  	dma_pa = data->dma_pa;

  
  	memset(dma_va, 0, data->dma_size);
  
  	dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);

  	dma_pa = roundup(dma_pa, ILO_START_ALIGN);

  
  	/*
  	 * Create two ccb's, one with virt addrs, one with phys addrs.
  	 * Copy the phys addr ccb to device shared mem.
  	 */
  	ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
  	ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);
  
  	fifo_setup(dma_va, NR_QENTRY);
  	driver_ccb->ccb_u1.send_fifobar = dma_va + FIFOHANDLESIZE;

  	ilo_ccb->ccb_u1.send_fifobar_pa = dma_pa + FIFOHANDLESIZE;

  	dma_va += fifo_sz(NR_QENTRY);
  	dma_pa += fifo_sz(NR_QENTRY);
  
  	dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);

  	dma_pa = roundup(dma_pa, ILO_CACHE_SZ);

  
  	fifo_setup(dma_va, NR_QENTRY);
  	driver_ccb->ccb_u3.recv_fifobar = dma_va + FIFOHANDLESIZE;

  	ilo_ccb->ccb_u3.recv_fifobar_pa = dma_pa + FIFOHANDLESIZE;

  	dma_va += fifo_sz(NR_QENTRY);
  	dma_pa += fifo_sz(NR_QENTRY);
  
  	driver_ccb->ccb_u2.send_desc = dma_va;

  	ilo_ccb->ccb_u2.send_desc_pa = dma_pa;

  	dma_pa += desc_mem_sz(NR_QENTRY);
  	dma_va += desc_mem_sz(NR_QENTRY);
  
  	driver_ccb->ccb_u4.recv_desc = dma_va;

  	ilo_ccb->ccb_u4.recv_desc_pa = dma_pa;

  
  	driver_ccb->channel = slot;
  	ilo_ccb->channel = slot;
  
  	driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
  	ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */

  	return 0;
  }
  
  static void ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
  {
  	int pkt_id, pkt_sz;
  	struct ccb *driver_ccb = &data->driver_ccb;

  	/* copy the ccb with physical addrs to device memory */
  	data->mapped_ccb = (struct ccb __iomem *)
  				(hw->ram_vaddr + (slot * ILOHW_CCB_SZ));

  	memcpy_toio(data->mapped_ccb, &data->ilo_ccb, sizeof(struct ccb));

  
  	/* put packets on the send and receive queues */
  	pkt_sz = 0;
  	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
  		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
  		doorbell_set(driver_ccb);
  	}
  
  	pkt_sz = desc_mem_sz(1);
  	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
  		ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);

  	/* the ccb is ready to use */

  	doorbell_clr(driver_ccb);

  }
  
  static int ilo_ccb_verify(struct ilo_hwinfo *hw, struct ccb_data *data)
  {
  	int pkt_id, i;
  	struct ccb *driver_ccb = &data->driver_ccb;

  
  	/* make sure iLO is really handling requests */

  	for (i = MAX_WAIT; i > 0; i--) {

  		if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
  			break;

  		udelay(WAIT_TIME);

  	}

  	if (i == 0) {
  		dev_err(&hw->ilo_dev->dev, "Open could not dequeue a packet
  ");
  		return -EBUSY;

  	}

  	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
  	doorbell_set(driver_ccb);

  	return 0;

  }
  
  static inline int is_channel_reset(struct ccb *ccb)
  {
  	/* check for this particular channel needing a reset */
  	return FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset;
  }
  
  static inline void set_channel_reset(struct ccb *ccb)
  {
  	/* set a flag indicating this channel needs a reset */
  	FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset = 1;
  }

  static inline int get_device_outbound(struct ilo_hwinfo *hw)
  {
  	return ioread32(&hw->mmio_vaddr[DB_OUT]);
  }
  
  static inline int is_db_reset(int db_out)
  {
  	return db_out & (1 << DB_RESET);
  }

  static inline int is_device_reset(struct ilo_hwinfo *hw)
  {
  	/* check for global reset condition */

  	return is_db_reset(get_device_outbound(hw));
  }
  
  static inline void clear_pending_db(struct ilo_hwinfo *hw, int clr)
  {
  	iowrite32(clr, &hw->mmio_vaddr[DB_OUT]);

  }
  
  static inline void clear_device(struct ilo_hwinfo *hw)
  {
  	/* clear the device (reset bits, pending channel entries) */

  	clear_pending_db(hw, -1);

  }

  static inline void ilo_enable_interrupts(struct ilo_hwinfo *hw)
  {
  	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) | 1, &hw->mmio_vaddr[DB_IRQ]);
  }
  
  static inline void ilo_disable_interrupts(struct ilo_hwinfo *hw)
  {
  	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) & ~1,
  		 &hw->mmio_vaddr[DB_IRQ]);
  }
  
  static void ilo_set_reset(struct ilo_hwinfo *hw)

  {
  	int slot;
  
  	/*
  	 * Mapped memory is zeroed on ilo reset, so set a per ccb flag
  	 * to indicate that this ccb needs to be closed and reopened.
  	 */
  	for (slot = 0; slot < MAX_CCB; slot++) {
  		if (!hw->ccb_alloc[slot])
  			continue;
  		set_channel_reset(&hw->ccb_alloc[slot]->driver_ccb);
  	}

  }
  
  static ssize_t ilo_read(struct file *fp, char __user *buf,
  			size_t len, loff_t *off)
  {
  	int err, found, cnt, pkt_id, pkt_len;

  	struct ccb_data *data = fp->private_data;
  	struct ccb *driver_ccb = &data->driver_ccb;
  	struct ilo_hwinfo *hw = data->ilo_hw;

  	void *pkt;

  	if (is_channel_reset(driver_ccb)) {

  		/*
  		 * If the device has been reset, applications
  		 * need to close and reopen all ccbs.
  		 */

  		return -ENODEV;
  	}
  
  	/*
  	 * This function is to be called when data is expected
  	 * in the channel, and will return an error if no packet is found
  	 * during the loop below.  The sleep/retry logic is to allow
  	 * applications to call read() immediately post write(),
  	 * and give iLO some time to process the sent packet.
  	 */
  	cnt = 20;
  	do {
  		/* look for a received packet */
  		found = ilo_pkt_dequeue(hw, driver_ccb, RECVQ, &pkt_id,
  					&pkt_len, &pkt);
  		if (found)
  			break;
  		cnt--;
  		msleep(100);
  	} while (!found && cnt);
  
  	if (!found)
  		return -EAGAIN;
  
  	/* only copy the length of the received packet */
  	if (pkt_len < len)
  		len = pkt_len;
  
  	err = copy_to_user(buf, pkt, len);
  
  	/* return the received packet to the queue */
  	ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, desc_mem_sz(1));
  
  	return err ? -EFAULT : len;
  }
  
  static ssize_t ilo_write(struct file *fp, const char __user *buf,
  			 size_t len, loff_t *off)
  {
  	int err, pkt_id, pkt_len;

  	struct ccb_data *data = fp->private_data;
  	struct ccb *driver_ccb = &data->driver_ccb;
  	struct ilo_hwinfo *hw = data->ilo_hw;

  	void *pkt;

  	if (is_channel_reset(driver_ccb))

  		return -ENODEV;

  
  	/* get a packet to send the user command */
  	if (!ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, &pkt_len, &pkt))
  		return -EBUSY;
  
  	/* limit the length to the length of the packet */
  	if (pkt_len < len)
  		len = pkt_len;
  
  	/* on failure, set the len to 0 to return empty packet to the device */
  	err = copy_from_user(pkt, buf, len);
  	if (err)
  		len = 0;
  
  	/* send the packet */
  	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, len);
  	doorbell_set(driver_ccb);
  
  	return err ? -EFAULT : len;
  }

  static unsigned int ilo_poll(struct file *fp, poll_table *wait)
  {
  	struct ccb_data *data = fp->private_data;
  	struct ccb *driver_ccb = &data->driver_ccb;
  
  	poll_wait(fp, &data->ccb_waitq, wait);
  
  	if (is_channel_reset(driver_ccb))
  		return POLLERR;
  	else if (ilo_pkt_recv(data->ilo_hw, driver_ccb))
  		return POLLIN | POLLRDNORM;
  
  	return 0;
  }

  static int ilo_close(struct inode *ip, struct file *fp)
  {
  	int slot;
  	struct ccb_data *data;
  	struct ilo_hwinfo *hw;

  	unsigned long flags;

  
  	slot = iminor(ip) % MAX_CCB;
  	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);

  	spin_lock(&hw->open_lock);

  
  	if (hw->ccb_alloc[slot]->ccb_cnt == 1) {
  
  		data = fp->private_data;

  		spin_lock_irqsave(&hw->alloc_lock, flags);
  		hw->ccb_alloc[slot] = NULL;
  		spin_unlock_irqrestore(&hw->alloc_lock, flags);

  		ilo_ccb_close(hw->ilo_dev, data);
  
  		kfree(data);

  	} else
  		hw->ccb_alloc[slot]->ccb_cnt--;

  	spin_unlock(&hw->open_lock);

  
  	return 0;
  }
  
  static int ilo_open(struct inode *ip, struct file *fp)
  {
  	int slot, error;
  	struct ccb_data *data;
  	struct ilo_hwinfo *hw;

  	unsigned long flags;

  
  	slot = iminor(ip) % MAX_CCB;
  	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
  
  	/* new ccb allocation */
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;

  	spin_lock(&hw->open_lock);

  
  	/* each fd private_data holds sw/hw view of ccb */
  	if (hw->ccb_alloc[slot] == NULL) {
  		/* create a channel control block for this minor */

  		error = ilo_ccb_setup(hw, data, slot);
  		if (error) {

  			kfree(data);

  			goto out;
  		}

  		data->ccb_cnt = 1;
  		data->ccb_excl = fp->f_flags & O_EXCL;
  		data->ilo_hw = hw;
  		init_waitqueue_head(&data->ccb_waitq);

  		/* write the ccb to hw */

  		spin_lock_irqsave(&hw->alloc_lock, flags);

  		ilo_ccb_open(hw, data, slot);

  		hw->ccb_alloc[slot] = data;
  		spin_unlock_irqrestore(&hw->alloc_lock, flags);

  
  		/* make sure the channel is functional */
  		error = ilo_ccb_verify(hw, data);
  		if (error) {

  
  			spin_lock_irqsave(&hw->alloc_lock, flags);
  			hw->ccb_alloc[slot] = NULL;
  			spin_unlock_irqrestore(&hw->alloc_lock, flags);

  			ilo_ccb_close(hw->ilo_dev, data);

  			kfree(data);
  			goto out;
  		}

  	} else {
  		kfree(data);
  		if (fp->f_flags & O_EXCL || hw->ccb_alloc[slot]->ccb_excl) {
  			/*
  			 * The channel exists, and either this open
  			 * or a previous open of this channel wants
  			 * exclusive access.
  			 */
  			error = -EBUSY;
  		} else {
  			hw->ccb_alloc[slot]->ccb_cnt++;
  			error = 0;
  		}
  	}

  out:

  	spin_unlock(&hw->open_lock);

  
  	if (!error)
  		fp->private_data = hw->ccb_alloc[slot];
  
  	return error;
  }
  
  static const struct file_operations ilo_fops = {
  	.owner		= THIS_MODULE,
  	.read		= ilo_read,
  	.write		= ilo_write,

  	.poll		= ilo_poll,

  	.open 		= ilo_open,
  	.release 	= ilo_close,

  	.llseek		= noop_llseek,

  };

  static irqreturn_t ilo_isr(int irq, void *data)
  {
  	struct ilo_hwinfo *hw = data;
  	int pending, i;
  
  	spin_lock(&hw->alloc_lock);
  
  	/* check for ccbs which have data */
  	pending = get_device_outbound(hw);
  	if (!pending) {
  		spin_unlock(&hw->alloc_lock);
  		return IRQ_NONE;
  	}
  
  	if (is_db_reset(pending)) {
  		/* wake up all ccbs if the device was reset */
  		pending = -1;
  		ilo_set_reset(hw);
  	}
  
  	for (i = 0; i < MAX_CCB; i++) {
  		if (!hw->ccb_alloc[i])
  			continue;
  		if (pending & (1 << i))
  			wake_up_interruptible(&hw->ccb_alloc[i]->ccb_waitq);
  	}
  
  	/* clear the device of the channels that have been handled */
  	clear_pending_db(hw, pending);
  
  	spin_unlock(&hw->alloc_lock);
  
  	return IRQ_HANDLED;
  }

  static void ilo_unmap_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
  {
  	pci_iounmap(pdev, hw->db_vaddr);
  	pci_iounmap(pdev, hw->ram_vaddr);
  	pci_iounmap(pdev, hw->mmio_vaddr);
  }
  
  static int __devinit ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
  {
  	int error = -ENOMEM;
  
  	/* map the memory mapped i/o registers */
  	hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
  	if (hw->mmio_vaddr == NULL) {
  		dev_err(&pdev->dev, "Error mapping mmio
  ");
  		goto out;
  	}
  
  	/* map the adapter shared memory region */
  	hw->ram_vaddr = pci_iomap(pdev, 2, MAX_CCB * ILOHW_CCB_SZ);
  	if (hw->ram_vaddr == NULL) {
  		dev_err(&pdev->dev, "Error mapping shared mem
  ");
  		goto mmio_free;
  	}
  
  	/* map the doorbell aperture */
  	hw->db_vaddr = pci_iomap(pdev, 3, MAX_CCB * ONE_DB_SIZE);
  	if (hw->db_vaddr == NULL) {
  		dev_err(&pdev->dev, "Error mapping doorbell
  ");
  		goto ram_free;
  	}
  
  	return 0;
  ram_free:
  	pci_iounmap(pdev, hw->ram_vaddr);
  mmio_free:
  	pci_iounmap(pdev, hw->mmio_vaddr);
  out:
  	return error;
  }
  
  static void ilo_remove(struct pci_dev *pdev)
  {
  	int i, minor;
  	struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);
  
  	clear_device(ilo_hw);
  
  	minor = MINOR(ilo_hw->cdev.dev);
  	for (i = minor; i < minor + MAX_CCB; i++)
  		device_destroy(ilo_class, MKDEV(ilo_major, i));
  
  	cdev_del(&ilo_hw->cdev);

  	ilo_disable_interrupts(ilo_hw);
  	free_irq(pdev->irq, ilo_hw);

  	ilo_unmap_device(pdev, ilo_hw);
  	pci_release_regions(pdev);
  	pci_disable_device(pdev);
  	kfree(ilo_hw);
  	ilo_hwdev[(minor / MAX_CCB)] = 0;
  }
  
  static int __devinit ilo_probe(struct pci_dev *pdev,
  			       const struct pci_device_id *ent)
  {
  	int devnum, minor, start, error;
  	struct ilo_hwinfo *ilo_hw;
  
  	/* find a free range for device files */
  	for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
  		if (ilo_hwdev[devnum] == 0) {
  			ilo_hwdev[devnum] = 1;
  			break;
  		}
  	}
  
  	if (devnum == MAX_ILO_DEV) {
  		dev_err(&pdev->dev, "Error finding free device
  ");
  		return -ENODEV;
  	}
  
  	/* track global allocations for this device */
  	error = -ENOMEM;
  	ilo_hw = kzalloc(sizeof(*ilo_hw), GFP_KERNEL);
  	if (!ilo_hw)
  		goto out;
  
  	ilo_hw->ilo_dev = pdev;
  	spin_lock_init(&ilo_hw->alloc_lock);
  	spin_lock_init(&ilo_hw->fifo_lock);

  	spin_lock_init(&ilo_hw->open_lock);

  
  	error = pci_enable_device(pdev);
  	if (error)
  		goto free;
  
  	pci_set_master(pdev);
  
  	error = pci_request_regions(pdev, ILO_NAME);
  	if (error)
  		goto disable;
  
  	error = ilo_map_device(pdev, ilo_hw);
  	if (error)
  		goto free_regions;
  
  	pci_set_drvdata(pdev, ilo_hw);
  	clear_device(ilo_hw);

  	error = request_irq(pdev->irq, ilo_isr, IRQF_SHARED, "hpilo", ilo_hw);
  	if (error)
  		goto unmap;
  
  	ilo_enable_interrupts(ilo_hw);

  	cdev_init(&ilo_hw->cdev, &ilo_fops);
  	ilo_hw->cdev.owner = THIS_MODULE;
  	start = devnum * MAX_CCB;
  	error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), MAX_CCB);
  	if (error) {
  		dev_err(&pdev->dev, "Could not add cdev
  ");

  		goto remove_isr;

  	}
  
  	for (minor = 0 ; minor < MAX_CCB; minor++) {
  		struct device *dev;
  		dev = device_create(ilo_class, &pdev->dev,
  				    MKDEV(ilo_major, minor), NULL,
  				    "hpilo!d%dccb%d", devnum, minor);
  		if (IS_ERR(dev))
  			dev_err(&pdev->dev, "Could not create files
  ");
  	}
  
  	return 0;

  remove_isr:
  	ilo_disable_interrupts(ilo_hw);
  	free_irq(pdev->irq, ilo_hw);

  unmap:
  	ilo_unmap_device(pdev, ilo_hw);
  free_regions:
  	pci_release_regions(pdev);
  disable:
  	pci_disable_device(pdev);
  free:
  	kfree(ilo_hw);
  out:
  	ilo_hwdev[devnum] = 0;
  	return error;
  }
  
  static struct pci_device_id ilo_devices[] = {
  	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },

  	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3307) },

  	{ }
  };
  MODULE_DEVICE_TABLE(pci, ilo_devices);
  
  static struct pci_driver ilo_driver = {
  	.name 	  = ILO_NAME,
  	.id_table = ilo_devices,
  	.probe 	  = ilo_probe,
  	.remove   = __devexit_p(ilo_remove),
  };
  
  static int __init ilo_init(void)
  {
  	int error;
  	dev_t dev;
  
  	ilo_class = class_create(THIS_MODULE, "iLO");
  	if (IS_ERR(ilo_class)) {
  		error = PTR_ERR(ilo_class);
  		goto out;
  	}
  
  	error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
  	if (error)
  		goto class_destroy;
  
  	ilo_major = MAJOR(dev);
  
  	error =	pci_register_driver(&ilo_driver);
  	if (error)
  		goto chr_remove;
  
  	return 0;
  chr_remove:
  	unregister_chrdev_region(dev, MAX_OPEN);
  class_destroy:
  	class_destroy(ilo_class);
  out:
  	return error;
  }
  
  static void __exit ilo_exit(void)
  {
  	pci_unregister_driver(&ilo_driver);
  	unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
  	class_destroy(ilo_class);
  }

  MODULE_VERSION("1.2");

  MODULE_ALIAS(ILO_NAME);
  MODULE_DESCRIPTION(ILO_NAME);
  MODULE_AUTHOR("David Altobelli <david.altobelli@hp.com>");
  MODULE_LICENSE("GPL v2");
  
  module_init(ilo_init);
  module_exit(ilo_exit);