/*
   * driver/dma/coh901318.c
   *
   * Copyright (C) 2007-2009 ST-Ericsson
   * License terms: GNU General Public License (GPL) version 2
   * DMA driver for COH 901 318
   * Author: Per Friden <per.friden@stericsson.com>
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/kernel.h> /* printk() */
  #include <linux/fs.h> /* everything... */

  #include <linux/scatterlist.h>

  #include <linux/slab.h> /* kmalloc() */
  #include <linux/dmaengine.h>
  #include <linux/platform_device.h>
  #include <linux/device.h>
  #include <linux/irqreturn.h>
  #include <linux/interrupt.h>
  #include <linux/io.h>
  #include <linux/uaccess.h>
  #include <linux/debugfs.h>
  #include <mach/coh901318.h>
  
  #include "coh901318_lli.h"
  
  #define COHC_2_DEV(cohc) (&cohc->chan.dev->device)
  
  #ifdef VERBOSE_DEBUG
  #define COH_DBG(x) ({ if (1) x; 0; })
  #else
  #define COH_DBG(x) ({ if (0) x; 0; })
  #endif
  
  struct coh901318_desc {
  	struct dma_async_tx_descriptor desc;
  	struct list_head node;
  	struct scatterlist *sg;
  	unsigned int sg_len;

  	struct coh901318_lli *lli;

  	enum dma_data_direction dir;

  	unsigned long flags;

  	u32 head_config;
  	u32 head_ctrl;

  };
  
  struct coh901318_base {
  	struct device *dev;
  	void __iomem *virtbase;
  	struct coh901318_pool pool;
  	struct powersave pm;
  	struct dma_device dma_slave;
  	struct dma_device dma_memcpy;
  	struct coh901318_chan *chans;
  	struct coh901318_platform *platform;
  };
  
  struct coh901318_chan {
  	spinlock_t lock;
  	int allocated;
  	int completed;
  	int id;
  	int stopped;
  
  	struct work_struct free_work;
  	struct dma_chan chan;
  
  	struct tasklet_struct tasklet;
  
  	struct list_head active;
  	struct list_head queue;
  	struct list_head free;
  
  	unsigned long nbr_active_done;
  	unsigned long busy;

  	u32 runtime_addr;
  	u32 runtime_ctrl;

  	struct coh901318_base *base;
  };
  
  static void coh901318_list_print(struct coh901318_chan *cohc,
  				 struct coh901318_lli *lli)
  {

  	struct coh901318_lli *l = lli;

  	int i = 0;

  	while (l) {

  		dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"

  			 ", dst 0x%x, link 0x%x virt_link_addr 0x%p
  ",

  			 i, l, l->control, l->src_addr, l->dst_addr,

  			 l->link_addr, l->virt_link_addr);

  		i++;

  		l = l->virt_link_addr;

  	}
  }
  
  #ifdef CONFIG_DEBUG_FS
  
  #define COH901318_DEBUGFS_ASSIGN(x, y) (x = y)
  
  static struct coh901318_base *debugfs_dma_base;
  static struct dentry *dma_dentry;
  
  static int coh901318_debugfs_open(struct inode *inode, struct file *file)
  {
  
  	file->private_data = inode->i_private;
  	return 0;
  }
  
  static int coh901318_debugfs_read(struct file *file, char __user *buf,
  				  size_t count, loff_t *f_pos)
  {
  	u64 started_channels = debugfs_dma_base->pm.started_channels;
  	int pool_count = debugfs_dma_base->pool.debugfs_pool_counter;
  	int i;
  	int ret = 0;
  	char *dev_buf;
  	char *tmp;
  	int dev_size;
  
  	dev_buf = kmalloc(4*1024, GFP_KERNEL);
  	if (dev_buf == NULL)
  		goto err_kmalloc;
  	tmp = dev_buf;

  	tmp += sprintf(tmp, "DMA -- enabled dma channels
  ");

  
  	for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
  		if (started_channels & (1 << i))
  			tmp += sprintf(tmp, "channel %d
  ", i);
  
  	tmp += sprintf(tmp, "Pool alloc nbr %d
  ", pool_count);
  	dev_size = tmp  - dev_buf;
  
  	/* No more to read if offset != 0 */
  	if (*f_pos > dev_size)
  		goto out;
  
  	if (count > dev_size - *f_pos)
  		count = dev_size - *f_pos;
  
  	if (copy_to_user(buf, dev_buf + *f_pos, count))
  		ret = -EINVAL;
  	ret = count;
  	*f_pos += count;
  
   out:
  	kfree(dev_buf);
  	return ret;
  
   err_kmalloc:
  	return 0;
  }
  
  static const struct file_operations coh901318_debugfs_status_operations = {
  	.owner		= THIS_MODULE,
  	.open		= coh901318_debugfs_open,
  	.read		= coh901318_debugfs_read,

  	.llseek		= default_llseek,

  };
  
  
  static int __init init_coh901318_debugfs(void)
  {
  
  	dma_dentry = debugfs_create_dir("dma", NULL);
  
  	(void) debugfs_create_file("status",
  				   S_IFREG | S_IRUGO,
  				   dma_dentry, NULL,
  				   &coh901318_debugfs_status_operations);
  	return 0;
  }
  
  static void __exit exit_coh901318_debugfs(void)
  {
  	debugfs_remove_recursive(dma_dentry);
  }
  
  module_init(init_coh901318_debugfs);
  module_exit(exit_coh901318_debugfs);
  #else
  
  #define COH901318_DEBUGFS_ASSIGN(x, y)
  
  #endif /* CONFIG_DEBUG_FS */
  
  static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
  {
  	return container_of(chan, struct coh901318_chan, chan);
  }
  
  static inline dma_addr_t
  cohc_dev_addr(struct coh901318_chan *cohc)
  {

  	/* Runtime supplied address will take precedence */
  	if (cohc->runtime_addr)
  		return cohc->runtime_addr;

  	return cohc->base->platform->chan_conf[cohc->id].dev_addr;
  }
  
  static inline const struct coh901318_params *
  cohc_chan_param(struct coh901318_chan *cohc)
  {
  	return &cohc->base->platform->chan_conf[cohc->id].param;
  }
  
  static inline const struct coh_dma_channel *
  cohc_chan_conf(struct coh901318_chan *cohc)
  {
  	return &cohc->base->platform->chan_conf[cohc->id];
  }
  
  static void enable_powersave(struct coh901318_chan *cohc)
  {
  	unsigned long flags;
  	struct powersave *pm = &cohc->base->pm;
  
  	spin_lock_irqsave(&pm->lock, flags);
  
  	pm->started_channels &= ~(1ULL << cohc->id);
  
  	if (!pm->started_channels) {
  		/* DMA no longer intends to access memory */
  		cohc->base->platform->access_memory_state(cohc->base->dev,
  							  false);
  	}
  
  	spin_unlock_irqrestore(&pm->lock, flags);
  }
  static void disable_powersave(struct coh901318_chan *cohc)
  {
  	unsigned long flags;
  	struct powersave *pm = &cohc->base->pm;
  
  	spin_lock_irqsave(&pm->lock, flags);
  
  	if (!pm->started_channels) {
  		/* DMA intends to access memory */
  		cohc->base->platform->access_memory_state(cohc->base->dev,
  							  true);
  	}
  
  	pm->started_channels |= (1ULL << cohc->id);
  
  	spin_unlock_irqrestore(&pm->lock, flags);
  }
  
  static inline int coh901318_set_ctrl(struct coh901318_chan *cohc, u32 control)
  {
  	int channel = cohc->id;
  	void __iomem *virtbase = cohc->base->virtbase;
  
  	writel(control,
  	       virtbase + COH901318_CX_CTRL +
  	       COH901318_CX_CTRL_SPACING * channel);
  	return 0;
  }
  
  static inline int coh901318_set_conf(struct coh901318_chan *cohc, u32 conf)
  {
  	int channel = cohc->id;
  	void __iomem *virtbase = cohc->base->virtbase;
  
  	writel(conf,
  	       virtbase + COH901318_CX_CFG +
  	       COH901318_CX_CFG_SPACING*channel);
  	return 0;
  }
  
  
  static int coh901318_start(struct coh901318_chan *cohc)
  {
  	u32 val;
  	int channel = cohc->id;
  	void __iomem *virtbase = cohc->base->virtbase;
  
  	disable_powersave(cohc);
  
  	val = readl(virtbase + COH901318_CX_CFG +
  		    COH901318_CX_CFG_SPACING * channel);
  
  	/* Enable channel */
  	val |= COH901318_CX_CFG_CH_ENABLE;
  	writel(val, virtbase + COH901318_CX_CFG +
  	       COH901318_CX_CFG_SPACING * channel);
  
  	return 0;
  }
  
  static int coh901318_prep_linked_list(struct coh901318_chan *cohc,

  				      struct coh901318_lli *lli)

  {
  	int channel = cohc->id;
  	void __iomem *virtbase = cohc->base->virtbase;
  
  	BUG_ON(readl(virtbase + COH901318_CX_STAT +
  		     COH901318_CX_STAT_SPACING*channel) &
  	       COH901318_CX_STAT_ACTIVE);

  	writel(lli->src_addr,

  	       virtbase + COH901318_CX_SRC_ADDR +
  	       COH901318_CX_SRC_ADDR_SPACING * channel);

  	writel(lli->dst_addr, virtbase +

  	       COH901318_CX_DST_ADDR +
  	       COH901318_CX_DST_ADDR_SPACING * channel);

  	writel(lli->link_addr, virtbase + COH901318_CX_LNK_ADDR +

  	       COH901318_CX_LNK_ADDR_SPACING * channel);

  	writel(lli->control, virtbase + COH901318_CX_CTRL +

  	       COH901318_CX_CTRL_SPACING * channel);
  
  	return 0;
  }
  static dma_cookie_t
  coh901318_assign_cookie(struct coh901318_chan *cohc,
  			struct coh901318_desc *cohd)
  {
  	dma_cookie_t cookie = cohc->chan.cookie;
  
  	if (++cookie < 0)
  		cookie = 1;
  
  	cohc->chan.cookie = cookie;
  	cohd->desc.cookie = cookie;
  
  	return cookie;
  }
  
  static struct coh901318_desc *
  coh901318_desc_get(struct coh901318_chan *cohc)
  {
  	struct coh901318_desc *desc;
  
  	if (list_empty(&cohc->free)) {
  		/* alloc new desc because we're out of used ones
  		 * TODO: alloc a pile of descs instead of just one,
  		 * avoid many small allocations.
  		 */

  		desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);

  		if (desc == NULL)
  			goto out;
  		INIT_LIST_HEAD(&desc->node);

  		dma_async_tx_descriptor_init(&desc->desc, &cohc->chan);

  	} else {
  		/* Reuse an old desc. */
  		desc = list_first_entry(&cohc->free,
  					struct coh901318_desc,
  					node);
  		list_del(&desc->node);

  		/* Initialize it a bit so it's not insane */
  		desc->sg = NULL;
  		desc->sg_len = 0;
  		desc->desc.callback = NULL;
  		desc->desc.callback_param = NULL;

  	}
  
   out:
  	return desc;
  }
  
  static void
  coh901318_desc_free(struct coh901318_chan *cohc, struct coh901318_desc *cohd)
  {
  	list_add_tail(&cohd->node, &cohc->free);
  }
  
  /* call with irq lock held */
  static void
  coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
  {
  	list_add_tail(&desc->node, &cohc->active);

  }
  
  static struct coh901318_desc *
  coh901318_first_active_get(struct coh901318_chan *cohc)
  {
  	struct coh901318_desc *d;
  
  	if (list_empty(&cohc->active))
  		return NULL;
  
  	d = list_first_entry(&cohc->active,
  			     struct coh901318_desc,
  			     node);
  	return d;
  }
  
  static void
  coh901318_desc_remove(struct coh901318_desc *cohd)
  {
  	list_del(&cohd->node);
  }
  
  static void
  coh901318_desc_queue(struct coh901318_chan *cohc, struct coh901318_desc *desc)
  {
  	list_add_tail(&desc->node, &cohc->queue);
  }
  
  static struct coh901318_desc *
  coh901318_first_queued(struct coh901318_chan *cohc)
  {
  	struct coh901318_desc *d;
  
  	if (list_empty(&cohc->queue))
  		return NULL;
  
  	d = list_first_entry(&cohc->queue,
  			     struct coh901318_desc,
  			     node);
  	return d;
  }

  static inline u32 coh901318_get_bytes_in_lli(struct coh901318_lli *in_lli)
  {
  	struct coh901318_lli *lli = in_lli;
  	u32 bytes = 0;
  
  	while (lli) {
  		bytes += lli->control & COH901318_CX_CTRL_TC_VALUE_MASK;
  		lli = lli->virt_link_addr;
  	}
  	return bytes;
  }

  /*

   * Get the number of bytes left to transfer on this channel,
   * it is unwise to call this before stopping the channel for
   * absolute measures, but for a rough guess you can still call
   * it.

   */

  static u32 coh901318_get_bytes_left(struct dma_chan *chan)

  {

  	struct coh901318_chan *cohc = to_coh901318_chan(chan);

  	struct coh901318_desc *cohd;
  	struct list_head *pos;
  	unsigned long flags;
  	u32 left = 0;
  	int i = 0;

  
  	spin_lock_irqsave(&cohc->lock, flags);

  	/*
  	 * If there are many queued jobs, we iterate and add the
  	 * size of them all. We take a special look on the first
  	 * job though, since it is probably active.
  	 */
  	list_for_each(pos, &cohc->active) {
  		/*
  		 * The first job in the list will be working on the
  		 * hardware. The job can be stopped but still active,
  		 * so that the transfer counter is somewhere inside
  		 * the buffer.
  		 */
  		cohd = list_entry(pos, struct coh901318_desc, node);
  
  		if (i == 0) {
  			struct coh901318_lli *lli;
  			dma_addr_t ladd;
  
  			/* Read current transfer count value */
  			left = readl(cohc->base->virtbase +
  				     COH901318_CX_CTRL +
  				     COH901318_CX_CTRL_SPACING * cohc->id) &
  				COH901318_CX_CTRL_TC_VALUE_MASK;
  
  			/* See if the transfer is linked... */
  			ladd = readl(cohc->base->virtbase +
  				     COH901318_CX_LNK_ADDR +
  				     COH901318_CX_LNK_ADDR_SPACING *
  				     cohc->id) &
  				~COH901318_CX_LNK_LINK_IMMEDIATE;
  			/* Single transaction */
  			if (!ladd)
  				continue;
  
  			/*
  			 * Linked transaction, follow the lli, find the
  			 * currently processing lli, and proceed to the next
  			 */
  			lli = cohd->lli;
  			while (lli && lli->link_addr != ladd)
  				lli = lli->virt_link_addr;
  
  			if (lli)
  				lli = lli->virt_link_addr;
  
  			/*
  			 * Follow remaining lli links around to count the total
  			 * number of bytes left
  			 */
  			left += coh901318_get_bytes_in_lli(lli);
  		} else {
  			left += coh901318_get_bytes_in_lli(cohd->lli);
  		}
  		i++;
  	}
  
  	/* Also count bytes in the queued jobs */
  	list_for_each(pos, &cohc->queue) {
  		cohd = list_entry(pos, struct coh901318_desc, node);
  		left += coh901318_get_bytes_in_lli(cohd->lli);
  	}

  
  	spin_unlock_irqrestore(&cohc->lock, flags);

  	return left;

  }

  /*
   * Pauses a transfer without losing data. Enables power save.
   * Use this function in conjunction with coh901318_resume.
   */
  static void coh901318_pause(struct dma_chan *chan)

  {
  	u32 val;
  	unsigned long flags;
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	int channel = cohc->id;
  	void __iomem *virtbase = cohc->base->virtbase;
  
  	spin_lock_irqsave(&cohc->lock, flags);
  
  	/* Disable channel in HW */
  	val = readl(virtbase + COH901318_CX_CFG +
  		    COH901318_CX_CFG_SPACING * channel);

  	/* Stopping infinite transfer */

  	if ((val & COH901318_CX_CTRL_TC_ENABLE) == 0 &&
  	    (val & COH901318_CX_CFG_CH_ENABLE))
  		cohc->stopped = 1;
  
  
  	val &= ~COH901318_CX_CFG_CH_ENABLE;
  	/* Enable twice, HW bug work around */
  	writel(val, virtbase + COH901318_CX_CFG +
  	       COH901318_CX_CFG_SPACING * channel);
  	writel(val, virtbase + COH901318_CX_CFG +
  	       COH901318_CX_CFG_SPACING * channel);
  
  	/* Spin-wait for it to actually go inactive */
  	while (readl(virtbase + COH901318_CX_STAT+COH901318_CX_STAT_SPACING *
  		     channel) & COH901318_CX_STAT_ACTIVE)
  		cpu_relax();
  
  	/* Check if we stopped an active job */
  	if ((readl(virtbase + COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *
  		   channel) & COH901318_CX_CTRL_TC_VALUE_MASK) > 0)
  		cohc->stopped = 1;
  
  	enable_powersave(cohc);
  
  	spin_unlock_irqrestore(&cohc->lock, flags);
  }

  /* Resumes a transfer that has been stopped via 300_dma_stop(..).

     Power save is handled.
  */

  static void coh901318_resume(struct dma_chan *chan)

  {
  	u32 val;
  	unsigned long flags;
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	int channel = cohc->id;
  
  	spin_lock_irqsave(&cohc->lock, flags);
  
  	disable_powersave(cohc);
  
  	if (cohc->stopped) {
  		/* Enable channel in HW */
  		val = readl(cohc->base->virtbase + COH901318_CX_CFG +
  			    COH901318_CX_CFG_SPACING * channel);
  
  		val |= COH901318_CX_CFG_CH_ENABLE;
  
  		writel(val, cohc->base->virtbase + COH901318_CX_CFG +
  		       COH901318_CX_CFG_SPACING*channel);
  
  		cohc->stopped = 0;
  	}
  
  	spin_unlock_irqrestore(&cohc->lock, flags);
  }

  
  bool coh901318_filter_id(struct dma_chan *chan, void *chan_id)
  {
  	unsigned int ch_nr = (unsigned int) chan_id;
  
  	if (ch_nr == to_coh901318_chan(chan)->id)
  		return true;
  
  	return false;
  }
  EXPORT_SYMBOL(coh901318_filter_id);
  
  /*
   * DMA channel allocation
   */
  static int coh901318_config(struct coh901318_chan *cohc,
  			    struct coh901318_params *param)
  {
  	unsigned long flags;
  	const struct coh901318_params *p;
  	int channel = cohc->id;
  	void __iomem *virtbase = cohc->base->virtbase;
  
  	spin_lock_irqsave(&cohc->lock, flags);
  
  	if (param)
  		p = param;
  	else
  		p = &cohc->base->platform->chan_conf[channel].param;
  
  	/* Clear any pending BE or TC interrupt */
  	if (channel < 32) {
  		writel(1 << channel, virtbase + COH901318_BE_INT_CLEAR1);
  		writel(1 << channel, virtbase + COH901318_TC_INT_CLEAR1);
  	} else {
  		writel(1 << (channel - 32), virtbase +
  		       COH901318_BE_INT_CLEAR2);
  		writel(1 << (channel - 32), virtbase +
  		       COH901318_TC_INT_CLEAR2);
  	}
  
  	coh901318_set_conf(cohc, p->config);
  	coh901318_set_ctrl(cohc, p->ctrl_lli_last);
  
  	spin_unlock_irqrestore(&cohc->lock, flags);
  
  	return 0;
  }
  
  /* must lock when calling this function
   * start queued jobs, if any
   * TODO: start all queued jobs in one go
   *
   * Returns descriptor if queued job is started otherwise NULL.
   * If the queue is empty NULL is returned.
   */
  static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
  {

  	struct coh901318_desc *cohd;

  	/*
  	 * start queued jobs, if any

  	 * TODO: transmit all queued jobs in one go
  	 */

  	cohd = coh901318_first_queued(cohc);

  	if (cohd != NULL) {

  		/* Remove from queue */

  		coh901318_desc_remove(cohd);

  		/* initiate DMA job */
  		cohc->busy = 1;

  		coh901318_desc_submit(cohc, cohd);

  		/* Program the transaction head */
  		coh901318_set_conf(cohc, cohd->head_config);
  		coh901318_set_ctrl(cohc, cohd->head_ctrl);

  		coh901318_prep_linked_list(cohc, cohd->lli);

  		/* start dma job on this channel */

  		coh901318_start(cohc);
  
  	}

  	return cohd;

  }

  /*
   * This tasklet is called from the interrupt handler to
   * handle each descriptor (DMA job) that is sent to a channel.
   */

  static void dma_tasklet(unsigned long data)
  {
  	struct coh901318_chan *cohc = (struct coh901318_chan *) data;
  	struct coh901318_desc *cohd_fin;
  	unsigned long flags;
  	dma_async_tx_callback callback;
  	void *callback_param;

  	dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d"
  		 " nbr_active_done %ld
  ", __func__,
  		 cohc->id, cohc->nbr_active_done);

  	spin_lock_irqsave(&cohc->lock, flags);

  	/* get first active descriptor entry from list */

  	cohd_fin = coh901318_first_active_get(cohc);

  	if (cohd_fin == NULL)
  		goto err;

  	/* locate callback to client */
  	callback = cohd_fin->desc.callback;
  	callback_param = cohd_fin->desc.callback_param;

  	/* sign this job as completed on the channel */
  	cohc->completed = cohd_fin->desc.cookie;

  	/* release the lli allocation and remove the descriptor */

  	coh901318_lli_free(&cohc->base->pool, &cohd_fin->lli);

  	/* return desc to free-list */
  	coh901318_desc_remove(cohd_fin);
  	coh901318_desc_free(cohc, cohd_fin);

  	spin_unlock_irqrestore(&cohc->lock, flags);

  	/* Call the callback when we're done */
  	if (callback)
  		callback(callback_param);

  	spin_lock_irqsave(&cohc->lock, flags);

  	/*
  	 * If another interrupt fired while the tasklet was scheduling,
  	 * we don't get called twice, so we have this number of active
  	 * counter that keep track of the number of IRQs expected to
  	 * be handled for this channel. If there happen to be more than
  	 * one IRQ to be ack:ed, we simply schedule this tasklet again.
  	 */

  	cohc->nbr_active_done--;

  	if (cohc->nbr_active_done) {

  		dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
  			"came in while we were scheduling this tasklet
  ");

  		if (cohc_chan_conf(cohc)->priority_high)
  			tasklet_hi_schedule(&cohc->tasklet);
  		else
  			tasklet_schedule(&cohc->tasklet);
  	}

  	spin_unlock_irqrestore(&cohc->lock, flags);

  
  	return;
  
   err:
  	spin_unlock_irqrestore(&cohc->lock, flags);
  	dev_err(COHC_2_DEV(cohc), "[%s] No active dma desc
  ", __func__);
  }
  
  
  /* called from interrupt context */
  static void dma_tc_handle(struct coh901318_chan *cohc)
  {

  	/*
  	 * If the channel is not allocated, then we shouldn't have
  	 * any TC interrupts on it.
  	 */
  	if (!cohc->allocated) {
  		dev_err(COHC_2_DEV(cohc), "spurious interrupt from "
  			"unallocated channel
  ");

  		return;

  	}

  	spin_lock(&cohc->lock);

  	/*
  	 * When we reach this point, at least one queue item
  	 * should have been moved over from cohc->queue to
  	 * cohc->active and run to completion, that is why we're
  	 * getting a terminal count interrupt is it not?
  	 * If you get this BUG() the most probable cause is that
  	 * the individual nodes in the lli chain have IRQ enabled,
  	 * so check your platform config for lli chain ctrl.
  	 */
  	BUG_ON(list_empty(&cohc->active));

  	cohc->nbr_active_done++;

  	/*
  	 * This attempt to take a job from cohc->queue, put it
  	 * into cohc->active and start it.
  	 */

  	if (coh901318_queue_start(cohc) == NULL)

  		cohc->busy = 0;

  	spin_unlock(&cohc->lock);

  	/*
  	 * This tasklet will remove items from cohc->active
  	 * and thus terminates them.
  	 */

  	if (cohc_chan_conf(cohc)->priority_high)
  		tasklet_hi_schedule(&cohc->tasklet);
  	else
  		tasklet_schedule(&cohc->tasklet);
  }
  
  
  static irqreturn_t dma_irq_handler(int irq, void *dev_id)
  {
  	u32 status1;
  	u32 status2;
  	int i;
  	int ch;
  	struct coh901318_base *base  = dev_id;
  	struct coh901318_chan *cohc;
  	void __iomem *virtbase = base->virtbase;
  
  	status1 = readl(virtbase + COH901318_INT_STATUS1);
  	status2 = readl(virtbase + COH901318_INT_STATUS2);
  
  	if (unlikely(status1 == 0 && status2 == 0)) {
  		dev_warn(base->dev, "spurious DMA IRQ from no channel!
  ");
  		return IRQ_HANDLED;
  	}
  
  	/* TODO: consider handle IRQ in tasklet here to
  	 *       minimize interrupt latency */
  
  	/* Check the first 32 DMA channels for IRQ */
  	while (status1) {
  		/* Find first bit set, return as a number. */
  		i = ffs(status1) - 1;
  		ch = i;
  
  		cohc = &base->chans[ch];
  		spin_lock(&cohc->lock);
  
  		/* Mask off this bit */
  		status1 &= ~(1 << i);
  		/* Check the individual channel bits */
  		if (test_bit(i, virtbase + COH901318_BE_INT_STATUS1)) {
  			dev_crit(COHC_2_DEV(cohc),
  				 "DMA bus error on channel %d!
  ", ch);
  			BUG_ON(1);
  			/* Clear BE interrupt */
  			__set_bit(i, virtbase + COH901318_BE_INT_CLEAR1);
  		} else {
  			/* Caused by TC, really? */
  			if (unlikely(!test_bit(i, virtbase +
  					       COH901318_TC_INT_STATUS1))) {
  				dev_warn(COHC_2_DEV(cohc),
  					 "ignoring interrupt not caused by terminal count on channel %d
  ", ch);
  				/* Clear TC interrupt */
  				BUG_ON(1);
  				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
  			} else {
  				/* Enable powersave if transfer has finished */
  				if (!(readl(virtbase + COH901318_CX_STAT +
  					    COH901318_CX_STAT_SPACING*ch) &
  				      COH901318_CX_STAT_ENABLED)) {
  					enable_powersave(cohc);
  				}
  
  				/* Must clear TC interrupt before calling
  				 * dma_tc_handle

  				 * in case tc_handle initiate a new dma job

  				 */
  				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
  
  				dma_tc_handle(cohc);
  			}
  		}
  		spin_unlock(&cohc->lock);
  	}
  
  	/* Check the remaining 32 DMA channels for IRQ */
  	while (status2) {
  		/* Find first bit set, return as a number. */
  		i = ffs(status2) - 1;
  		ch = i + 32;
  		cohc = &base->chans[ch];
  		spin_lock(&cohc->lock);
  
  		/* Mask off this bit */
  		status2 &= ~(1 << i);
  		/* Check the individual channel bits */
  		if (test_bit(i, virtbase + COH901318_BE_INT_STATUS2)) {
  			dev_crit(COHC_2_DEV(cohc),
  				 "DMA bus error on channel %d!
  ", ch);
  			/* Clear BE interrupt */
  			BUG_ON(1);
  			__set_bit(i, virtbase + COH901318_BE_INT_CLEAR2);
  		} else {
  			/* Caused by TC, really? */
  			if (unlikely(!test_bit(i, virtbase +
  					       COH901318_TC_INT_STATUS2))) {
  				dev_warn(COHC_2_DEV(cohc),
  					 "ignoring interrupt not caused by terminal count on channel %d
  ", ch);
  				/* Clear TC interrupt */
  				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
  				BUG_ON(1);
  			} else {
  				/* Enable powersave if transfer has finished */
  				if (!(readl(virtbase + COH901318_CX_STAT +
  					    COH901318_CX_STAT_SPACING*ch) &
  				      COH901318_CX_STAT_ENABLED)) {
  					enable_powersave(cohc);
  				}
  				/* Must clear TC interrupt before calling
  				 * dma_tc_handle

  				 * in case tc_handle initiate a new dma job

  				 */
  				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
  
  				dma_tc_handle(cohc);
  			}
  		}
  		spin_unlock(&cohc->lock);
  	}
  
  	return IRQ_HANDLED;
  }
  
  static int coh901318_alloc_chan_resources(struct dma_chan *chan)
  {
  	struct coh901318_chan	*cohc = to_coh901318_chan(chan);

  	unsigned long flags;

  
  	dev_vdbg(COHC_2_DEV(cohc), "[%s] DMA channel %d
  ",
  		 __func__, cohc->id);
  
  	if (chan->client_count > 1)
  		return -EBUSY;

  	spin_lock_irqsave(&cohc->lock, flags);

  	coh901318_config(cohc, NULL);
  
  	cohc->allocated = 1;
  	cohc->completed = chan->cookie = 1;

  	spin_unlock_irqrestore(&cohc->lock, flags);

  	return 1;
  }
  
  static void
  coh901318_free_chan_resources(struct dma_chan *chan)
  {
  	struct coh901318_chan	*cohc = to_coh901318_chan(chan);
  	int channel = cohc->id;
  	unsigned long flags;
  
  	spin_lock_irqsave(&cohc->lock, flags);
  
  	/* Disable HW */
  	writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CFG +
  	       COH901318_CX_CFG_SPACING*channel);
  	writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CTRL +
  	       COH901318_CX_CTRL_SPACING*channel);
  
  	cohc->allocated = 0;
  
  	spin_unlock_irqrestore(&cohc->lock, flags);

  	chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);

  }
  
  
  static dma_cookie_t
  coh901318_tx_submit(struct dma_async_tx_descriptor *tx)
  {
  	struct coh901318_desc *cohd = container_of(tx, struct coh901318_desc,
  						   desc);
  	struct coh901318_chan *cohc = to_coh901318_chan(tx->chan);
  	unsigned long flags;
  
  	spin_lock_irqsave(&cohc->lock, flags);
  
  	tx->cookie = coh901318_assign_cookie(cohc, cohd);
  
  	coh901318_desc_queue(cohc, cohd);
  
  	spin_unlock_irqrestore(&cohc->lock, flags);
  
  	return tx->cookie;
  }
  
  static struct dma_async_tx_descriptor *
  coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
  		      size_t size, unsigned long flags)
  {

  	struct coh901318_lli *lli;

  	struct coh901318_desc *cohd;
  	unsigned long flg;
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	int lli_len;
  	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;

  	int ret;

  
  	spin_lock_irqsave(&cohc->lock, flg);
  
  	dev_vdbg(COHC_2_DEV(cohc),
  		 "[%s] channel %d src 0x%x dest 0x%x size %d
  ",
  		 __func__, cohc->id, src, dest, size);
  
  	if (flags & DMA_PREP_INTERRUPT)
  		/* Trigger interrupt after last lli */
  		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
  
  	lli_len = size >> MAX_DMA_PACKET_SIZE_SHIFT;
  	if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)
  		lli_len++;

  	lli = coh901318_lli_alloc(&cohc->base->pool, lli_len);

  	if (lli == NULL)

  		goto err;

  	ret = coh901318_lli_fill_memcpy(

  		&cohc->base->pool, lli, src, size, dest,

  		cohc_chan_param(cohc)->ctrl_lli_chained,
  		ctrl_last);
  	if (ret)
  		goto err;

  	COH_DBG(coh901318_list_print(cohc, lli));

  	/* Pick a descriptor to handle this transfer */
  	cohd = coh901318_desc_get(cohc);

  	cohd->lli = lli;

  	cohd->flags = flags;

  	cohd->desc.tx_submit = coh901318_tx_submit;
  
  	spin_unlock_irqrestore(&cohc->lock, flg);
  
  	return &cohd->desc;
   err:
  	spin_unlock_irqrestore(&cohc->lock, flg);
  	return NULL;
  }
  
  static struct dma_async_tx_descriptor *
  coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
  			unsigned int sg_len, enum dma_data_direction direction,
  			unsigned long flags)
  {
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);

  	struct coh901318_lli *lli;

  	struct coh901318_desc *cohd;

  	const struct coh901318_params *params;

  	struct scatterlist *sg;
  	int len = 0;
  	int size;
  	int i;
  	u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
  	u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
  	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;

  	u32 config;

  	unsigned long flg;

  	int ret;

  
  	if (!sgl)
  		goto out;
  	if (sgl->length == 0)
  		goto out;
  
  	spin_lock_irqsave(&cohc->lock, flg);
  
  	dev_vdbg(COHC_2_DEV(cohc), "[%s] sg_len %d dir %d
  ",
  		 __func__, sg_len, direction);
  
  	if (flags & DMA_PREP_INTERRUPT)
  		/* Trigger interrupt after last lli */
  		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;

  	params = cohc_chan_param(cohc);
  	config = params->config;

  	/*
  	 * Add runtime-specific control on top, make
  	 * sure the bits you set per peripheral channel are
  	 * cleared in the default config from the platform.
  	 */
  	ctrl_chained |= cohc->runtime_ctrl;
  	ctrl_last |= cohc->runtime_ctrl;
  	ctrl |= cohc->runtime_ctrl;

  	if (direction == DMA_TO_DEVICE) {
  		u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
  			COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;

  		config |= COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY;

  		ctrl_chained |= tx_flags;
  		ctrl_last |= tx_flags;
  		ctrl |= tx_flags;
  	} else if (direction == DMA_FROM_DEVICE) {
  		u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
  			COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;

  		config |= COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY;

  		ctrl_chained |= rx_flags;
  		ctrl_last |= rx_flags;
  		ctrl |= rx_flags;
  	} else
  		goto err_direction;

  	/* The dma only supports transmitting packages up to
  	 * MAX_DMA_PACKET_SIZE. Calculate to total number of
  	 * dma elemts required to send the entire sg list
  	 */
  	for_each_sg(sgl, sg, sg_len, i) {
  		unsigned int factor;
  		size = sg_dma_len(sg);
  
  		if (size <= MAX_DMA_PACKET_SIZE) {
  			len++;
  			continue;
  		}
  
  		factor = size >> MAX_DMA_PACKET_SIZE_SHIFT;
  		if ((factor << MAX_DMA_PACKET_SIZE_SHIFT) < size)
  			factor++;
  
  		len += factor;
  	}

  	pr_debug("Allocate %d lli:s for this transfer
  ", len);

  	lli = coh901318_lli_alloc(&cohc->base->pool, len);

  	if (lli == NULL)

  		goto err_dma_alloc;

  	/* initiate allocated lli list */
  	ret = coh901318_lli_fill_sg(&cohc->base->pool, lli, sgl, sg_len,

  				    cohc_dev_addr(cohc),
  				    ctrl_chained,
  				    ctrl,
  				    ctrl_last,
  				    direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
  	if (ret)
  		goto err_lli_fill;

  	COH_DBG(coh901318_list_print(cohc, lli));

  	/* Pick a descriptor to handle this transfer */
  	cohd = coh901318_desc_get(cohc);

  	cohd->head_config = config;
  	/*
  	 * Set the default head ctrl for the channel to the one from the
  	 * lli, things may have changed due to odd buffer alignment
  	 * etc.
  	 */
  	cohd->head_ctrl = lli->control;

  	cohd->dir = direction;
  	cohd->flags = flags;
  	cohd->desc.tx_submit = coh901318_tx_submit;

  	cohd->lli = lli;

  	spin_unlock_irqrestore(&cohc->lock, flg);
  
  	return &cohd->desc;

   err_lli_fill:

   err_dma_alloc:
   err_direction:

  	spin_unlock_irqrestore(&cohc->lock, flg);
   out:
  	return NULL;
  }
  
  static enum dma_status

  coh901318_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
  		 struct dma_tx_state *txstate)

  {
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	dma_cookie_t last_used;
  	dma_cookie_t last_complete;
  	int ret;
  
  	last_complete = cohc->completed;
  	last_used = chan->cookie;
  
  	ret = dma_async_is_complete(cookie, last_complete, last_used);

  	dma_set_tx_state(txstate, last_complete, last_used,
  			 coh901318_get_bytes_left(chan));

  	if (ret == DMA_IN_PROGRESS && cohc->stopped)
  		ret = DMA_PAUSED;

  
  	return ret;
  }
  
  static void
  coh901318_issue_pending(struct dma_chan *chan)
  {
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	unsigned long flags;
  
  	spin_lock_irqsave(&cohc->lock, flags);

  	/*
  	 * Busy means that pending jobs are already being processed,
  	 * and then there is no point in starting the queue: the
  	 * terminal count interrupt on the channel will take the next
  	 * job on the queue and execute it anyway.
  	 */

  	if (!cohc->busy)
  		coh901318_queue_start(cohc);
  
  	spin_unlock_irqrestore(&cohc->lock, flags);
  }

  /*
   * Here we wrap in the runtime dma control interface
   */
  struct burst_table {
  	int burst_8bit;
  	int burst_16bit;
  	int burst_32bit;
  	u32 reg;
  };
  
  static const struct burst_table burst_sizes[] = {
  	{
  		.burst_8bit = 64,
  		.burst_16bit = 32,
  		.burst_32bit = 16,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_64_BYTES,
  	},
  	{
  		.burst_8bit = 48,
  		.burst_16bit = 24,
  		.burst_32bit = 12,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_48_BYTES,
  	},
  	{
  		.burst_8bit = 32,
  		.burst_16bit = 16,
  		.burst_32bit = 8,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_32_BYTES,
  	},
  	{
  		.burst_8bit = 16,
  		.burst_16bit = 8,
  		.burst_32bit = 4,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_16_BYTES,
  	},
  	{
  		.burst_8bit = 8,
  		.burst_16bit = 4,
  		.burst_32bit = 2,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_8_BYTES,
  	},
  	{
  		.burst_8bit = 4,
  		.burst_16bit = 2,
  		.burst_32bit = 1,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_4_BYTES,
  	},
  	{
  		.burst_8bit = 2,
  		.burst_16bit = 1,
  		.burst_32bit = 0,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_2_BYTES,
  	},
  	{
  		.burst_8bit = 1,
  		.burst_16bit = 0,
  		.burst_32bit = 0,
  		.reg = COH901318_CX_CTRL_BURST_COUNT_1_BYTE,
  	},
  };
  
  static void coh901318_dma_set_runtimeconfig(struct dma_chan *chan,
  			struct dma_slave_config *config)
  {
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	dma_addr_t addr;
  	enum dma_slave_buswidth addr_width;
  	u32 maxburst;
  	u32 runtime_ctrl = 0;
  	int i = 0;
  
  	/* We only support mem to per or per to mem transfers */
  	if (config->direction == DMA_FROM_DEVICE) {
  		addr = config->src_addr;
  		addr_width = config->src_addr_width;
  		maxburst = config->src_maxburst;
  	} else if (config->direction == DMA_TO_DEVICE) {
  		addr = config->dst_addr;
  		addr_width = config->dst_addr_width;
  		maxburst = config->dst_maxburst;
  	} else {
  		dev_err(COHC_2_DEV(cohc), "illegal channel mode
  ");
  		return;
  	}
  
  	dev_dbg(COHC_2_DEV(cohc), "configure channel for %d byte transfers
  ",
  		addr_width);
  	switch (addr_width)  {
  	case DMA_SLAVE_BUSWIDTH_1_BYTE:
  		runtime_ctrl |=
  			COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS |
  			COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS;
  
  		while (i < ARRAY_SIZE(burst_sizes)) {
  			if (burst_sizes[i].burst_8bit <= maxburst)
  				break;
  			i++;
  		}
  
  		break;
  	case DMA_SLAVE_BUSWIDTH_2_BYTES:
  		runtime_ctrl |=
  			COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS |
  			COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS;
  
  		while (i < ARRAY_SIZE(burst_sizes)) {
  			if (burst_sizes[i].burst_16bit <= maxburst)
  				break;
  			i++;
  		}
  
  		break;
  	case DMA_SLAVE_BUSWIDTH_4_BYTES:
  		/* Direction doesn't matter here, it's 32/32 bits */
  		runtime_ctrl |=
  			COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS |
  			COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS;
  
  		while (i < ARRAY_SIZE(burst_sizes)) {
  			if (burst_sizes[i].burst_32bit <= maxburst)
  				break;
  			i++;
  		}
  
  		break;
  	default:
  		dev_err(COHC_2_DEV(cohc),
  			"bad runtimeconfig: alien address width
  ");
  		return;
  	}
  
  	runtime_ctrl |= burst_sizes[i].reg;
  	dev_dbg(COHC_2_DEV(cohc),
  		"selected burst size %d bytes for address width %d bytes, maxburst %d
  ",
  		burst_sizes[i].burst_8bit, addr_width, maxburst);
  
  	cohc->runtime_addr = addr;
  	cohc->runtime_ctrl = runtime_ctrl;
  }

  static int

  coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
  		  unsigned long arg)

  {
  	unsigned long flags;
  	struct coh901318_chan *cohc = to_coh901318_chan(chan);
  	struct coh901318_desc *cohd;
  	void __iomem *virtbase = cohc->base->virtbase;

  	if (cmd == DMA_SLAVE_CONFIG) {
  		struct dma_slave_config *config =
  			(struct dma_slave_config *) arg;
  
  		coh901318_dma_set_runtimeconfig(chan, config);
  		return 0;
  	  }

  	if (cmd == DMA_PAUSE) {
  		coh901318_pause(chan);
  		return 0;
  	}
  
  	if (cmd == DMA_RESUME) {
  		coh901318_resume(chan);
  		return 0;
  	}
  
  	if (cmd != DMA_TERMINATE_ALL)
  		return -ENXIO;

  	/* The remainder of this function terminates the transfer */
  	coh901318_pause(chan);

  	spin_lock_irqsave(&cohc->lock, flags);
  
  	/* Clear any pending BE or TC interrupt */
  	if (cohc->id < 32) {
  		writel(1 << cohc->id, virtbase + COH901318_BE_INT_CLEAR1);
  		writel(1 << cohc->id, virtbase + COH901318_TC_INT_CLEAR1);
  	} else {
  		writel(1 << (cohc->id - 32), virtbase +
  		       COH901318_BE_INT_CLEAR2);
  		writel(1 << (cohc->id - 32), virtbase +
  		       COH901318_TC_INT_CLEAR2);
  	}
  
  	enable_powersave(cohc);
  
  	while ((cohd = coh901318_first_active_get(cohc))) {
  		/* release the lli allocation*/

  		coh901318_lli_free(&cohc->base->pool, &cohd->lli);

  		/* return desc to free-list */

  		coh901318_desc_remove(cohd);

  		coh901318_desc_free(cohc, cohd);
  	}
  
  	while ((cohd = coh901318_first_queued(cohc))) {
  		/* release the lli allocation*/

  		coh901318_lli_free(&cohc->base->pool, &cohd->lli);

  		/* return desc to free-list */

  		coh901318_desc_remove(cohd);

  		coh901318_desc_free(cohc, cohd);
  	}
  
  
  	cohc->nbr_active_done = 0;
  	cohc->busy = 0;

  
  	spin_unlock_irqrestore(&cohc->lock, flags);

  
  	return 0;

  }

  void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
  			 struct coh901318_base *base)
  {
  	int chans_i;
  	int i = 0;
  	struct coh901318_chan *cohc;
  
  	INIT_LIST_HEAD(&dma->channels);
  
  	for (chans_i = 0; pick_chans[chans_i] != -1; chans_i += 2) {
  		for (i = pick_chans[chans_i]; i <= pick_chans[chans_i+1]; i++) {
  			cohc = &base->chans[i];
  
  			cohc->base = base;
  			cohc->chan.device = dma;
  			cohc->id = i;
  
  			/* TODO: do we really need this lock if only one
  			 * client is connected to each channel?
  			 */
  
  			spin_lock_init(&cohc->lock);

  			cohc->nbr_active_done = 0;
  			cohc->busy = 0;
  			INIT_LIST_HEAD(&cohc->free);
  			INIT_LIST_HEAD(&cohc->active);
  			INIT_LIST_HEAD(&cohc->queue);
  
  			tasklet_init(&cohc->tasklet, dma_tasklet,
  				     (unsigned long) cohc);
  
  			list_add_tail(&cohc->chan.device_node,
  				      &dma->channels);
  		}
  	}
  }
  
  static int __init coh901318_probe(struct platform_device *pdev)
  {
  	int err = 0;
  	struct coh901318_platform *pdata;
  	struct coh901318_base *base;
  	int irq;
  	struct resource *io;
  
  	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!io)
  		goto err_get_resource;
  
  	/* Map DMA controller registers to virtual memory */
  	if (request_mem_region(io->start,
  			       resource_size(io),
  			       pdev->dev.driver->name) == NULL) {
  		err = -EBUSY;
  		goto err_request_mem;
  	}
  
  	pdata = pdev->dev.platform_data;
  	if (!pdata)
  		goto err_no_platformdata;
  
  	base = kmalloc(ALIGN(sizeof(struct coh901318_base), 4) +
  		       pdata->max_channels *
  		       sizeof(struct coh901318_chan),
  		       GFP_KERNEL);
  	if (!base)
  		goto err_alloc_coh_dma_channels;
  
  	base->chans = ((void *)base) + ALIGN(sizeof(struct coh901318_base), 4);
  
  	base->virtbase = ioremap(io->start, resource_size(io));
  	if (!base->virtbase) {
  		err = -ENOMEM;
  		goto err_no_ioremap;
  	}
  
  	base->dev = &pdev->dev;
  	base->platform = pdata;
  	spin_lock_init(&base->pm.lock);
  	base->pm.started_channels = 0;
  
  	COH901318_DEBUGFS_ASSIGN(debugfs_dma_base, base);
  
  	platform_set_drvdata(pdev, base);
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0)
  		goto err_no_irq;
  
  	err = request_irq(irq, dma_irq_handler, IRQF_DISABLED,
  			  "coh901318", base);
  	if (err) {
  		dev_crit(&pdev->dev,
  			 "Cannot allocate IRQ for DMA controller!
  ");
  		goto err_request_irq;
  	}
  
  	err = coh901318_pool_create(&base->pool, &pdev->dev,
  				    sizeof(struct coh901318_lli),
  				    32);
  	if (err)
  		goto err_pool_create;
  
  	/* init channels for device transfers */
  	coh901318_base_init(&base->dma_slave,  base->platform->chans_slave,
  			    base);
  
  	dma_cap_zero(base->dma_slave.cap_mask);
  	dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
  
  	base->dma_slave.device_alloc_chan_resources = coh901318_alloc_chan_resources;
  	base->dma_slave.device_free_chan_resources = coh901318_free_chan_resources;
  	base->dma_slave.device_prep_slave_sg = coh901318_prep_slave_sg;

  	base->dma_slave.device_tx_status = coh901318_tx_status;

  	base->dma_slave.device_issue_pending = coh901318_issue_pending;

  	base->dma_slave.device_control = coh901318_control;

  	base->dma_slave.dev = &pdev->dev;
  
  	err = dma_async_device_register(&base->dma_slave);
  
  	if (err)
  		goto err_register_slave;
  
  	/* init channels for memcpy */
  	coh901318_base_init(&base->dma_memcpy, base->platform->chans_memcpy,
  			    base);
  
  	dma_cap_zero(base->dma_memcpy.cap_mask);
  	dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
  
  	base->dma_memcpy.device_alloc_chan_resources = coh901318_alloc_chan_resources;
  	base->dma_memcpy.device_free_chan_resources = coh901318_free_chan_resources;
  	base->dma_memcpy.device_prep_dma_memcpy = coh901318_prep_memcpy;

  	base->dma_memcpy.device_tx_status = coh901318_tx_status;

  	base->dma_memcpy.device_issue_pending = coh901318_issue_pending;

  	base->dma_memcpy.device_control = coh901318_control;

  	base->dma_memcpy.dev = &pdev->dev;

  	/*
  	 * This controller can only access address at even 32bit boundaries,
  	 * i.e. 2^2
  	 */
  	base->dma_memcpy.copy_align = 2;

  	err = dma_async_device_register(&base->dma_memcpy);
  
  	if (err)
  		goto err_register_memcpy;

  	dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x
  ",

  		(u32) base->virtbase);
  
  	return err;
  
   err_register_memcpy:
  	dma_async_device_unregister(&base->dma_slave);
   err_register_slave:
  	coh901318_pool_destroy(&base->pool);
   err_pool_create:
  	free_irq(platform_get_irq(pdev, 0), base);
   err_request_irq:
   err_no_irq:
  	iounmap(base->virtbase);
   err_no_ioremap:
  	kfree(base);
   err_alloc_coh_dma_channels:
   err_no_platformdata:
  	release_mem_region(pdev->resource->start,
  			   resource_size(pdev->resource));
   err_request_mem:
   err_get_resource:
  	return err;
  }
  
  static int __exit coh901318_remove(struct platform_device *pdev)
  {
  	struct coh901318_base *base = platform_get_drvdata(pdev);
  
  	dma_async_device_unregister(&base->dma_memcpy);
  	dma_async_device_unregister(&base->dma_slave);
  	coh901318_pool_destroy(&base->pool);
  	free_irq(platform_get_irq(pdev, 0), base);

  	iounmap(base->virtbase);

  	kfree(base);

  	release_mem_region(pdev->resource->start,
  			   resource_size(pdev->resource));
  	return 0;
  }
  
  
  static struct platform_driver coh901318_driver = {
  	.remove = __exit_p(coh901318_remove),
  	.driver = {
  		.name	= "coh901318",
  	},
  };
  
  int __init coh901318_init(void)
  {
  	return platform_driver_probe(&coh901318_driver, coh901318_probe);
  }

  subsys_initcall(coh901318_init);

  
  void __exit coh901318_exit(void)
  {
  	platform_driver_unregister(&coh901318_driver);
  }
  module_exit(coh901318_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Per Friden");