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   1/*
   2 * driver/dma/coh901318.c
   3 *
   4 * Copyright (C) 2007-2009 ST-Ericsson
   5 * License terms: GNU General Public License (GPL) version 2
   6 * DMA driver for COH 901 318
   7 * Author: Per Friden <per.friden@stericsson.com>
   8 */
   9
  10#include <linux/init.h>
  11#include <linux/module.h>
  12#include <linux/kernel.h> /* printk() */
  13#include <linux/fs.h> /* everything... */
  14#include <linux/scatterlist.h>
  15#include <linux/slab.h> /* kmalloc() */
  16#include <linux/dmaengine.h>
  17#include <linux/platform_device.h>
  18#include <linux/device.h>
  19#include <linux/irqreturn.h>
  20#include <linux/interrupt.h>
  21#include <linux/io.h>
  22#include <linux/uaccess.h>
  23#include <linux/debugfs.h>
  24#include <mach/coh901318.h>
  25
  26#include "coh901318_lli.h"
  27#include "dmaengine.h"
  28
  29#define COHC_2_DEV(cohc) (&cohc->chan.dev->device)
  30
  31#ifdef VERBOSE_DEBUG
  32#define COH_DBG(x) ({ if (1) x; 0; })
  33#else
  34#define COH_DBG(x) ({ if (0) x; 0; })
  35#endif
  36
  37struct coh901318_desc {
  38	struct dma_async_tx_descriptor desc;
  39	struct list_head node;
  40	struct scatterlist *sg;
  41	unsigned int sg_len;
  42	struct coh901318_lli *lli;
  43	enum dma_transfer_direction dir;
  44	unsigned long flags;
  45	u32 head_config;
  46	u32 head_ctrl;
  47};
  48
  49struct coh901318_base {
  50	struct device *dev;
  51	void __iomem *virtbase;
  52	struct coh901318_pool pool;
  53	struct powersave pm;
  54	struct dma_device dma_slave;
  55	struct dma_device dma_memcpy;
  56	struct coh901318_chan *chans;
  57	struct coh901318_platform *platform;
  58};
  59
  60struct coh901318_chan {
  61	spinlock_t lock;
  62	int allocated;
  63	int id;
  64	int stopped;
  65
  66	struct work_struct free_work;
  67	struct dma_chan chan;
  68
  69	struct tasklet_struct tasklet;
  70
  71	struct list_head active;
  72	struct list_head queue;
  73	struct list_head free;
  74
  75	unsigned long nbr_active_done;
  76	unsigned long busy;
  77
  78	u32 runtime_addr;
  79	u32 runtime_ctrl;
  80
  81	struct coh901318_base *base;
  82};
  83
  84static void coh901318_list_print(struct coh901318_chan *cohc,
  85				 struct coh901318_lli *lli)
  86{
  87	struct coh901318_lli *l = lli;
  88	int i = 0;
  89
  90	while (l) {
  91		dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"
  92			 ", dst 0x%x, link 0x%x virt_link_addr 0x%p\n",
  93			 i, l, l->control, l->src_addr, l->dst_addr,
  94			 l->link_addr, l->virt_link_addr);
  95		i++;
  96		l = l->virt_link_addr;
  97	}
  98}
  99
 100#ifdef CONFIG_DEBUG_FS
 101
 102#define COH901318_DEBUGFS_ASSIGN(x, y) (x = y)
 103
 104static struct coh901318_base *debugfs_dma_base;
 105static struct dentry *dma_dentry;
 106
 107static int coh901318_debugfs_read(struct file *file, char __user *buf,
 108				  size_t count, loff_t *f_pos)
 109{
 110	u64 started_channels = debugfs_dma_base->pm.started_channels;
 111	int pool_count = debugfs_dma_base->pool.debugfs_pool_counter;
 112	int i;
 113	int ret = 0;
 114	char *dev_buf;
 115	char *tmp;
 116	int dev_size;
 117
 118	dev_buf = kmalloc(4*1024, GFP_KERNEL);
 119	if (dev_buf == NULL)
 120		goto err_kmalloc;
 121	tmp = dev_buf;
 122
 123	tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
 124
 125	for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
 126		if (started_channels & (1 << i))
 127			tmp += sprintf(tmp, "channel %d\n", i);
 128
 129	tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);
 130	dev_size = tmp  - dev_buf;
 131
 132	/* No more to read if offset != 0 */
 133	if (*f_pos > dev_size)
 134		goto out;
 135
 136	if (count > dev_size - *f_pos)
 137		count = dev_size - *f_pos;
 138
 139	if (copy_to_user(buf, dev_buf + *f_pos, count))
 140		ret = -EINVAL;
 141	ret = count;
 142	*f_pos += count;
 143
 144 out:
 145	kfree(dev_buf);
 146	return ret;
 147
 148 err_kmalloc:
 149	return 0;
 150}
 151
 152static const struct file_operations coh901318_debugfs_status_operations = {
 153	.owner		= THIS_MODULE,
 154	.open		= simple_open,
 155	.read		= coh901318_debugfs_read,
 156	.llseek		= default_llseek,
 157};
 158
 159
 160static int __init init_coh901318_debugfs(void)
 161{
 162
 163	dma_dentry = debugfs_create_dir("dma", NULL);
 164
 165	(void) debugfs_create_file("status",
 166				   S_IFREG | S_IRUGO,
 167				   dma_dentry, NULL,
 168				   &coh901318_debugfs_status_operations);
 169	return 0;
 170}
 171
 172static void __exit exit_coh901318_debugfs(void)
 173{
 174	debugfs_remove_recursive(dma_dentry);
 175}
 176
 177module_init(init_coh901318_debugfs);
 178module_exit(exit_coh901318_debugfs);
 179#else
 180
 181#define COH901318_DEBUGFS_ASSIGN(x, y)
 182
 183#endif /* CONFIG_DEBUG_FS */
 184
 185static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
 186{
 187	return container_of(chan, struct coh901318_chan, chan);
 188}
 189
 190static inline dma_addr_t
 191cohc_dev_addr(struct coh901318_chan *cohc)
 192{
 193	/* Runtime supplied address will take precedence */
 194	if (cohc->runtime_addr)
 195		return cohc->runtime_addr;
 196	return cohc->base->platform->chan_conf[cohc->id].dev_addr;
 197}
 198
 199static inline const struct coh901318_params *
 200cohc_chan_param(struct coh901318_chan *cohc)
 201{
 202	return &cohc->base->platform->chan_conf[cohc->id].param;
 203}
 204
 205static inline const struct coh_dma_channel *
 206cohc_chan_conf(struct coh901318_chan *cohc)
 207{
 208	return &cohc->base->platform->chan_conf[cohc->id];
 209}
 210
 211static void enable_powersave(struct coh901318_chan *cohc)
 212{
 213	unsigned long flags;
 214	struct powersave *pm = &cohc->base->pm;
 215
 216	spin_lock_irqsave(&pm->lock, flags);
 217
 218	pm->started_channels &= ~(1ULL << cohc->id);
 219
 220	if (!pm->started_channels) {
 221		/* DMA no longer intends to access memory */
 222		cohc->base->platform->access_memory_state(cohc->base->dev,
 223							  false);
 224	}
 225
 226	spin_unlock_irqrestore(&pm->lock, flags);
 227}
 228static void disable_powersave(struct coh901318_chan *cohc)
 229{
 230	unsigned long flags;
 231	struct powersave *pm = &cohc->base->pm;
 232
 233	spin_lock_irqsave(&pm->lock, flags);
 234
 235	if (!pm->started_channels) {
 236		/* DMA intends to access memory */
 237		cohc->base->platform->access_memory_state(cohc->base->dev,
 238							  true);
 239	}
 240
 241	pm->started_channels |= (1ULL << cohc->id);
 242
 243	spin_unlock_irqrestore(&pm->lock, flags);
 244}
 245
 246static inline int coh901318_set_ctrl(struct coh901318_chan *cohc, u32 control)
 247{
 248	int channel = cohc->id;
 249	void __iomem *virtbase = cohc->base->virtbase;
 250
 251	writel(control,
 252	       virtbase + COH901318_CX_CTRL +
 253	       COH901318_CX_CTRL_SPACING * channel);
 254	return 0;
 255}
 256
 257static inline int coh901318_set_conf(struct coh901318_chan *cohc, u32 conf)
 258{
 259	int channel = cohc->id;
 260	void __iomem *virtbase = cohc->base->virtbase;
 261
 262	writel(conf,
 263	       virtbase + COH901318_CX_CFG +
 264	       COH901318_CX_CFG_SPACING*channel);
 265	return 0;
 266}
 267
 268
 269static int coh901318_start(struct coh901318_chan *cohc)
 270{
 271	u32 val;
 272	int channel = cohc->id;
 273	void __iomem *virtbase = cohc->base->virtbase;
 274
 275	disable_powersave(cohc);
 276
 277	val = readl(virtbase + COH901318_CX_CFG +
 278		    COH901318_CX_CFG_SPACING * channel);
 279
 280	/* Enable channel */
 281	val |= COH901318_CX_CFG_CH_ENABLE;
 282	writel(val, virtbase + COH901318_CX_CFG +
 283	       COH901318_CX_CFG_SPACING * channel);
 284
 285	return 0;
 286}
 287
 288static int coh901318_prep_linked_list(struct coh901318_chan *cohc,
 289				      struct coh901318_lli *lli)
 290{
 291	int channel = cohc->id;
 292	void __iomem *virtbase = cohc->base->virtbase;
 293
 294	BUG_ON(readl(virtbase + COH901318_CX_STAT +
 295		     COH901318_CX_STAT_SPACING*channel) &
 296	       COH901318_CX_STAT_ACTIVE);
 297
 298	writel(lli->src_addr,
 299	       virtbase + COH901318_CX_SRC_ADDR +
 300	       COH901318_CX_SRC_ADDR_SPACING * channel);
 301
 302	writel(lli->dst_addr, virtbase +
 303	       COH901318_CX_DST_ADDR +
 304	       COH901318_CX_DST_ADDR_SPACING * channel);
 305
 306	writel(lli->link_addr, virtbase + COH901318_CX_LNK_ADDR +
 307	       COH901318_CX_LNK_ADDR_SPACING * channel);
 308
 309	writel(lli->control, virtbase + COH901318_CX_CTRL +
 310	       COH901318_CX_CTRL_SPACING * channel);
 311
 312	return 0;
 313}
 314
 315static struct coh901318_desc *
 316coh901318_desc_get(struct coh901318_chan *cohc)
 317{
 318	struct coh901318_desc *desc;
 319
 320	if (list_empty(&cohc->free)) {
 321		/* alloc new desc because we're out of used ones
 322		 * TODO: alloc a pile of descs instead of just one,
 323		 * avoid many small allocations.
 324		 */
 325		desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
 326		if (desc == NULL)
 327			goto out;
 328		INIT_LIST_HEAD(&desc->node);
 329		dma_async_tx_descriptor_init(&desc->desc, &cohc->chan);
 330	} else {
 331		/* Reuse an old desc. */
 332		desc = list_first_entry(&cohc->free,
 333					struct coh901318_desc,
 334					node);
 335		list_del(&desc->node);
 336		/* Initialize it a bit so it's not insane */
 337		desc->sg = NULL;
 338		desc->sg_len = 0;
 339		desc->desc.callback = NULL;
 340		desc->desc.callback_param = NULL;
 341	}
 342
 343 out:
 344	return desc;
 345}
 346
 347static void
 348coh901318_desc_free(struct coh901318_chan *cohc, struct coh901318_desc *cohd)
 349{
 350	list_add_tail(&cohd->node, &cohc->free);
 351}
 352
 353/* call with irq lock held */
 354static void
 355coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
 356{
 357	list_add_tail(&desc->node, &cohc->active);
 358}
 359
 360static struct coh901318_desc *
 361coh901318_first_active_get(struct coh901318_chan *cohc)
 362{
 363	struct coh901318_desc *d;
 364
 365	if (list_empty(&cohc->active))
 366		return NULL;
 367
 368	d = list_first_entry(&cohc->active,
 369			     struct coh901318_desc,
 370			     node);
 371	return d;
 372}
 373
 374static void
 375coh901318_desc_remove(struct coh901318_desc *cohd)
 376{
 377	list_del(&cohd->node);
 378}
 379
 380static void
 381coh901318_desc_queue(struct coh901318_chan *cohc, struct coh901318_desc *desc)
 382{
 383	list_add_tail(&desc->node, &cohc->queue);
 384}
 385
 386static struct coh901318_desc *
 387coh901318_first_queued(struct coh901318_chan *cohc)
 388{
 389	struct coh901318_desc *d;
 390
 391	if (list_empty(&cohc->queue))
 392		return NULL;
 393
 394	d = list_first_entry(&cohc->queue,
 395			     struct coh901318_desc,
 396			     node);
 397	return d;
 398}
 399
 400static inline u32 coh901318_get_bytes_in_lli(struct coh901318_lli *in_lli)
 401{
 402	struct coh901318_lli *lli = in_lli;
 403	u32 bytes = 0;
 404
 405	while (lli) {
 406		bytes += lli->control & COH901318_CX_CTRL_TC_VALUE_MASK;
 407		lli = lli->virt_link_addr;
 408	}
 409	return bytes;
 410}
 411
 412/*
 413 * Get the number of bytes left to transfer on this channel,
 414 * it is unwise to call this before stopping the channel for
 415 * absolute measures, but for a rough guess you can still call
 416 * it.
 417 */
 418static u32 coh901318_get_bytes_left(struct dma_chan *chan)
 419{
 420	struct coh901318_chan *cohc = to_coh901318_chan(chan);
 421	struct coh901318_desc *cohd;
 422	struct list_head *pos;
 423	unsigned long flags;
 424	u32 left = 0;
 425	int i = 0;
 426
 427	spin_lock_irqsave(&cohc->lock, flags);
 428
 429	/*
 430	 * If there are many queued jobs, we iterate and add the
 431	 * size of them all. We take a special look on the first
 432	 * job though, since it is probably active.
 433	 */
 434	list_for_each(pos, &cohc->active) {
 435		/*
 436		 * The first job in the list will be working on the
 437		 * hardware. The job can be stopped but still active,
 438		 * so that the transfer counter is somewhere inside
 439		 * the buffer.
 440		 */
 441		cohd = list_entry(pos, struct coh901318_desc, node);
 442
 443		if (i == 0) {
 444			struct coh901318_lli *lli;
 445			dma_addr_t ladd;
 446
 447			/* Read current transfer count value */
 448			left = readl(cohc->base->virtbase +
 449				     COH901318_CX_CTRL +
 450				     COH901318_CX_CTRL_SPACING * cohc->id) &
 451				COH901318_CX_CTRL_TC_VALUE_MASK;
 452
 453			/* See if the transfer is linked... */
 454			ladd = readl(cohc->base->virtbase +
 455				     COH901318_CX_LNK_ADDR +
 456				     COH901318_CX_LNK_ADDR_SPACING *
 457				     cohc->id) &
 458				~COH901318_CX_LNK_LINK_IMMEDIATE;
 459			/* Single transaction */
 460			if (!ladd)
 461				continue;
 462
 463			/*
 464			 * Linked transaction, follow the lli, find the
 465			 * currently processing lli, and proceed to the next
 466			 */
 467			lli = cohd->lli;
 468			while (lli && lli->link_addr != ladd)
 469				lli = lli->virt_link_addr;
 470
 471			if (lli)
 472				lli = lli->virt_link_addr;
 473
 474			/*
 475			 * Follow remaining lli links around to count the total
 476			 * number of bytes left
 477			 */
 478			left += coh901318_get_bytes_in_lli(lli);
 479		} else {
 480			left += coh901318_get_bytes_in_lli(cohd->lli);
 481		}
 482		i++;
 483	}
 484
 485	/* Also count bytes in the queued jobs */
 486	list_for_each(pos, &cohc->queue) {
 487		cohd = list_entry(pos, struct coh901318_desc, node);
 488		left += coh901318_get_bytes_in_lli(cohd->lli);
 489	}
 490
 491	spin_unlock_irqrestore(&cohc->lock, flags);
 492
 493	return left;
 494}
 495
 496/*
 497 * Pauses a transfer without losing data. Enables power save.
 498 * Use this function in conjunction with coh901318_resume.
 499 */
 500static void coh901318_pause(struct dma_chan *chan)
 501{
 502	u32 val;
 503	unsigned long flags;
 504	struct coh901318_chan *cohc = to_coh901318_chan(chan);
 505	int channel = cohc->id;
 506	void __iomem *virtbase = cohc->base->virtbase;
 507
 508	spin_lock_irqsave(&cohc->lock, flags);
 509
 510	/* Disable channel in HW */
 511	val = readl(virtbase + COH901318_CX_CFG +
 512		    COH901318_CX_CFG_SPACING * channel);
 513
 514	/* Stopping infinite transfer */
 515	if ((val & COH901318_CX_CTRL_TC_ENABLE) == 0 &&
 516	    (val & COH901318_CX_CFG_CH_ENABLE))
 517		cohc->stopped = 1;
 518
 519
 520	val &= ~COH901318_CX_CFG_CH_ENABLE;
 521	/* Enable twice, HW bug work around */
 522	writel(val, virtbase + COH901318_CX_CFG +
 523	       COH901318_CX_CFG_SPACING * channel);
 524	writel(val, virtbase + COH901318_CX_CFG +
 525	       COH901318_CX_CFG_SPACING * channel);
 526
 527	/* Spin-wait for it to actually go inactive */
 528	while (readl(virtbase + COH901318_CX_STAT+COH901318_CX_STAT_SPACING *
 529		     channel) & COH901318_CX_STAT_ACTIVE)
 530		cpu_relax();
 531
 532	/* Check if we stopped an active job */
 533	if ((readl(virtbase + COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *
 534		   channel) & COH901318_CX_CTRL_TC_VALUE_MASK) > 0)
 535		cohc->stopped = 1;
 536
 537	enable_powersave(cohc);
 538
 539	spin_unlock_irqrestore(&cohc->lock, flags);
 540}
 541
 542/* Resumes a transfer that has been stopped via 300_dma_stop(..).
 543   Power save is handled.
 544*/
 545static void coh901318_resume(struct dma_chan *chan)
 546{
 547	u32 val;
 548	unsigned long flags;
 549	struct coh901318_chan *cohc = to_coh901318_chan(chan);
 550	int channel = cohc->id;
 551
 552	spin_lock_irqsave(&cohc->lock, flags);
 553
 554	disable_powersave(cohc);
 555
 556	if (cohc->stopped) {
 557		/* Enable channel in HW */
 558		val = readl(cohc->base->virtbase + COH901318_CX_CFG +
 559			    COH901318_CX_CFG_SPACING * channel);
 560
 561		val |= COH901318_CX_CFG_CH_ENABLE;
 562
 563		writel(val, cohc->base->virtbase + COH901318_CX_CFG +
 564		       COH901318_CX_CFG_SPACING*channel);
 565
 566		cohc->stopped = 0;
 567	}
 568
 569	spin_unlock_irqrestore(&cohc->lock, flags);
 570}
 571
 572bool coh901318_filter_id(struct dma_chan *chan, void *chan_id)
 573{
 574	unsigned int ch_nr = (unsigned int) chan_id;
 575
 576	if (ch_nr == to_coh901318_chan(chan)->id)
 577		return true;
 578
 579	return false;
 580}
 581EXPORT_SYMBOL(coh901318_filter_id);
 582
 583/*
 584 * DMA channel allocation
 585 */
 586static int coh901318_config(struct coh901318_chan *cohc,
 587			    struct coh901318_params *param)
 588{
 589	unsigned long flags;
 590	const struct coh901318_params *p;
 591	int channel = cohc->id;
 592	void __iomem *virtbase = cohc->base->virtbase;
 593
 594	spin_lock_irqsave(&cohc->lock, flags);
 595
 596	if (param)
 597		p = param;
 598	else
 599		p = &cohc->base->platform->chan_conf[channel].param;
 600
 601	/* Clear any pending BE or TC interrupt */
 602	if (channel < 32) {
 603		writel(1 << channel, virtbase + COH901318_BE_INT_CLEAR1);
 604		writel(1 << channel, virtbase + COH901318_TC_INT_CLEAR1);
 605	} else {
 606		writel(1 << (channel - 32), virtbase +
 607		       COH901318_BE_INT_CLEAR2);
 608		writel(1 << (channel - 32), virtbase +
 609		       COH901318_TC_INT_CLEAR2);
 610	}
 611
 612	coh901318_set_conf(cohc, p->config);
 613	coh901318_set_ctrl(cohc, p->ctrl_lli_last);
 614
 615	spin_unlock_irqrestore(&cohc->lock, flags);
 616
 617	return 0;
 618}
 619
 620/* must lock when calling this function
 621 * start queued jobs, if any
 622 * TODO: start all queued jobs in one go
 623 *
 624 * Returns descriptor if queued job is started otherwise NULL.
 625 * If the queue is empty NULL is returned.
 626 */
 627static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
 628{
 629	struct coh901318_desc *cohd;
 630
 631	/*
 632	 * start queued jobs, if any
 633	 * TODO: transmit all queued jobs in one go
 634	 */
 635	cohd = coh901318_first_queued(cohc);
 636
 637	if (cohd != NULL) {
 638		/* Remove from queue */
 639		coh901318_desc_remove(cohd);
 640		/* initiate DMA job */
 641		cohc->busy = 1;
 642
 643		coh901318_desc_submit(cohc, cohd);
 644
 645		/* Program the transaction head */
 646		coh901318_set_conf(cohc, cohd->head_config);
 647		coh901318_set_ctrl(cohc, cohd->head_ctrl);
 648		coh901318_prep_linked_list(cohc, cohd->lli);
 649
 650		/* start dma job on this channel */
 651		coh901318_start(cohc);
 652
 653	}
 654
 655	return cohd;
 656}
 657
 658/*
 659 * This tasklet is called from the interrupt handler to
 660 * handle each descriptor (DMA job) that is sent to a channel.
 661 */
 662static void dma_tasklet(unsigned long data)
 663{
 664	struct coh901318_chan *cohc = (struct coh901318_chan *) data;
 665	struct coh901318_desc *cohd_fin;
 666	unsigned long flags;
 667	dma_async_tx_callback callback;
 668	void *callback_param;
 669
 670	dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d"
 671		 " nbr_active_done %ld\n", __func__,
 672		 cohc->id, cohc->nbr_active_done);
 673
 674	spin_lock_irqsave(&cohc->lock, flags);
 675
 676	/* get first active descriptor entry from list */
 677	cohd_fin = coh901318_first_active_get(cohc);
 678
 679	if (cohd_fin == NULL)
 680		goto err;
 681
 682	/* locate callback to client */
 683	callback = cohd_fin->desc.callback;
 684	callback_param = cohd_fin->desc.callback_param;
 685
 686	/* sign this job as completed on the channel */
 687	dma_cookie_complete(&cohd_fin->desc);
 688
 689	/* release the lli allocation and remove the descriptor */
 690	coh901318_lli_free(&cohc->base->pool, &cohd_fin->lli);
 691
 692	/* return desc to free-list */
 693	coh901318_desc_remove(cohd_fin);
 694	coh901318_desc_free(cohc, cohd_fin);
 695
 696	spin_unlock_irqrestore(&cohc->lock, flags);
 697
 698	/* Call the callback when we're done */
 699	if (callback)
 700		callback(callback_param);
 701
 702	spin_lock_irqsave(&cohc->lock, flags);
 703
 704	/*
 705	 * If another interrupt fired while the tasklet was scheduling,
 706	 * we don't get called twice, so we have this number of active
 707	 * counter that keep track of the number of IRQs expected to
 708	 * be handled for this channel. If there happen to be more than
 709	 * one IRQ to be ack:ed, we simply schedule this tasklet again.
 710	 */
 711	cohc->nbr_active_done--;
 712	if (cohc->nbr_active_done) {
 713		dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
 714			"came in while we were scheduling this tasklet\n");
 715		if (cohc_chan_conf(cohc)->priority_high)
 716			tasklet_hi_schedule(&cohc->tasklet);
 717		else
 718			tasklet_schedule(&cohc->tasklet);
 719	}
 720
 721	spin_unlock_irqrestore(&cohc->lock, flags);
 722
 723	return;
 724
 725 err:
 726	spin_unlock_irqrestore(&cohc->lock, flags);
 727	dev_err(COHC_2_DEV(cohc), "[%s] No active dma desc\n", __func__);
 728}
 729
 730
 731/* called from interrupt context */
 732static void dma_tc_handle(struct coh901318_chan *cohc)
 733{
 734	/*
 735	 * If the channel is not allocated, then we shouldn't have
 736	 * any TC interrupts on it.
 737	 */
 738	if (!cohc->allocated) {
 739		dev_err(COHC_2_DEV(cohc), "spurious interrupt from "
 740			"unallocated channel\n");
 741		return;
 742	}
 743
 744	spin_lock(&cohc->lock);
 745
 746	/*
 747	 * When we reach this point, at least one queue item
 748	 * should have been moved over from cohc->queue to
 749	 * cohc->active and run to completion, that is why we're
 750	 * getting a terminal count interrupt is it not?
 751	 * If you get this BUG() the most probable cause is that
 752	 * the individual nodes in the lli chain have IRQ enabled,
 753	 * so check your platform config for lli chain ctrl.
 754	 */
 755	BUG_ON(list_empty(&cohc->active));
 756
 757	cohc->nbr_active_done++;
 758
 759	/*
 760	 * This attempt to take a job from cohc->queue, put it
 761	 * into cohc->active and start it.
 762	 */
 763	if (coh901318_queue_start(cohc) == NULL)
 764		cohc->busy = 0;
 765
 766	spin_unlock(&cohc->lock);
 767
 768	/*
 769	 * This tasklet will remove items from cohc->active
 770	 * and thus terminates them.
 771	 */
 772	if (cohc_chan_conf(cohc)->priority_high)
 773		tasklet_hi_schedule(&cohc->tasklet);
 774	else
 775		tasklet_schedule(&cohc->tasklet);
 776}
 777
 778
 779static irqreturn_t dma_irq_handler(int irq, void *dev_id)
 780{
 781	u32 status1;
 782	u32 status2;
 783	int i;
 784	int ch;
 785	struct coh901318_base *base  = dev_id;
 786	struct coh901318_chan *cohc;
 787	void __iomem *virtbase = base->virtbase;
 788
 789	status1 = readl(virtbase + COH901318_INT_STATUS1);
 790	status2 = readl(virtbase + COH901318_INT_STATUS2);
 791
 792	if (unlikely(status1 == 0 && status2 == 0)) {
 793		dev_warn(base->dev, "spurious DMA IRQ from no channel!\n");
 794		return IRQ_HANDLED;
 795	}
 796
 797	/* TODO: consider handle IRQ in tasklet here to
 798	 *       minimize interrupt latency */
 799
 800	/* Check the first 32 DMA channels for IRQ */
 801	while (status1) {
 802		/* Find first bit set, return as a number. */
 803		i = ffs(status1) - 1;
 804		ch = i;
 805
 806		cohc = &base->chans[ch];
 807		spin_lock(&cohc->lock);
 808
 809		/* Mask off this bit */
 810		status1 &= ~(1 << i);
 811		/* Check the individual channel bits */
 812		if (test_bit(i, virtbase + COH901318_BE_INT_STATUS1)) {
 813			dev_crit(COHC_2_DEV(cohc),
 814				 "DMA bus error on channel %d!\n", ch);
 815			BUG_ON(1);
 816			/* Clear BE interrupt */
 817			__set_bit(i, virtbase + COH901318_BE_INT_CLEAR1);
 818		} else {
 819			/* Caused by TC, really? */
 820			if (unlikely(!test_bit(i, virtbase +
 821					       COH901318_TC_INT_STATUS1))) {
 822				dev_warn(COHC_2_DEV(cohc),
 823					 "ignoring interrupt not caused by terminal count on channel %d\n", ch);
 824				/* Clear TC interrupt */
 825				BUG_ON(1);
 826				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
 827			} else {
 828				/* Enable powersave if transfer has finished */
 829				if (!(readl(virtbase + COH901318_CX_STAT +
 830					    COH901318_CX_STAT_SPACING*ch) &
 831				      COH901318_CX_STAT_ENABLED)) {
 832					enable_powersave(cohc);
 833				}
 834
 835				/* Must clear TC interrupt before calling
 836				 * dma_tc_handle
 837				 * in case tc_handle initiate a new dma job
 838				 */
 839				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
 840
 841				dma_tc_handle(cohc);
 842			}
 843		}
 844		spin_unlock(&cohc->lock);
 845	}
 846
 847	/* Check the remaining 32 DMA channels for IRQ */
 848	while (status2) {
 849		/* Find first bit set, return as a number. */
 850		i = ffs(status2) - 1;
 851		ch = i + 32;
 852		cohc = &base->chans[ch];
 853		spin_lock(&cohc->lock);
 854
 855		/* Mask off this bit */
 856		status2 &= ~(1 << i);
 857		/* Check the individual channel bits */
 858		if (test_bit(i, virtbase + COH901318_BE_INT_STATUS2)) {
 859			dev_crit(COHC_2_DEV(cohc),
 860				 "DMA bus error on channel %d!\n", ch);
 861			/* Clear BE interrupt */
 862			BUG_ON(1);
 863			__set_bit(i, virtbase + COH901318_BE_INT_CLEAR2);
 864		} else {
 865			/* Caused by TC, really? */
 866			if (unlikely(!test_bit(i, virtbase +
 867					       COH901318_TC_INT_STATUS2))) {
 868				dev_warn(COHC_2_DEV(cohc),
 869					 "ignoring interrupt not caused by terminal count on channel %d\n", ch);
 870				/* Clear TC interrupt */
 871				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
 872				BUG_ON(1);
 873			} else {
 874				/* Enable powersave if transfer has finished */
 875				if (!(readl(virtbase + COH901318_CX_STAT +
 876					    COH901318_CX_STAT_SPACING*ch) &
 877				      COH901318_CX_STAT_ENABLED)) {
 878					enable_powersave(cohc);
 879				}
 880				/* Must clear TC interrupt before calling
 881				 * dma_tc_handle
 882				 * in case tc_handle initiate a new dma job
 883				 */
 884				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
 885
 886				dma_tc_handle(cohc);
 887			}
 888		}
 889		spin_unlock(&cohc->lock);
 890	}
 891
 892	return IRQ_HANDLED;
 893}
 894
 895static int coh901318_alloc_chan_resources(struct dma_chan *chan)
 896{
 897	struct coh901318_chan	*cohc = to_coh901318_chan(chan);
 898	unsigned long flags;
 899
 900	dev_vdbg(COHC_2_DEV(cohc), "[%s] DMA channel %d\n",
 901		 __func__, cohc->id);
 902
 903	if (chan->client_count > 1)
 904		return -EBUSY;
 905
 906	spin_lock_irqsave(&cohc->lock, flags);
 907
 908	coh901318_config(cohc, NULL);
 909
 910	cohc->allocated = 1;
 911	dma_cookie_init(chan);
 912
 913	spin_unlock_irqrestore(&cohc->lock, flags);
 914
 915	return 1;
 916}
 917
 918static void
 919coh901318_free_chan_resources(struct dma_chan *chan)
 920{
 921	struct coh901318_chan	*cohc = to_coh901318_chan(chan);
 922	int channel = cohc->id;
 923	unsigned long flags;
 924
 925	spin_lock_irqsave(&cohc->lock, flags);
 926
 927	/* Disable HW */
 928	writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CFG +
 929	       COH901318_CX_CFG_SPACING*channel);
 930	writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CTRL +
 931	       COH901318_CX_CTRL_SPACING*channel);
 932
 933	cohc->allocated = 0;
 934
 935	spin_unlock_irqrestore(&cohc->lock, flags);
 936
 937	chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
 938}
 939
 940
 941static dma_cookie_t
 942coh901318_tx_submit(struct dma_async_tx_descriptor *tx)
 943{
 944	struct coh901318_desc *cohd = container_of(tx, struct coh901318_desc,
 945						   desc);
 946	struct coh901318_chan *cohc = to_coh901318_chan(tx->chan);
 947	unsigned long flags;
 948	dma_cookie_t cookie;
 949
 950	spin_lock_irqsave(&cohc->lock, flags);
 951	cookie = dma_cookie_assign(tx);
 952
 953	coh901318_desc_queue(cohc, cohd);
 954
 955	spin_unlock_irqrestore(&cohc->lock, flags);
 956
 957	return cookie;
 958}
 959
 960static struct dma_async_tx_descriptor *
 961coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 962		      size_t size, unsigned long flags)
 963{
 964	struct coh901318_lli *lli;
 965	struct coh901318_desc *cohd;
 966	unsigned long flg;
 967	struct coh901318_chan *cohc = to_coh901318_chan(chan);
 968	int lli_len;
 969	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
 970	int ret;
 971
 972	spin_lock_irqsave(&cohc->lock, flg);
 973
 974	dev_vdbg(COHC_2_DEV(cohc),
 975		 "[%s] channel %d src 0x%x dest 0x%x size %d\n",
 976		 __func__, cohc->id, src, dest, size);
 977
 978	if (flags & DMA_PREP_INTERRUPT)
 979		/* Trigger interrupt after last lli */
 980		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
 981
 982	lli_len = size >> MAX_DMA_PACKET_SIZE_SHIFT;
 983	if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)
 984		lli_len++;
 985
 986	lli = coh901318_lli_alloc(&cohc->base->pool, lli_len);
 987
 988	if (lli == NULL)
 989		goto err;
 990
 991	ret = coh901318_lli_fill_memcpy(
 992		&cohc->base->pool, lli, src, size, dest,
 993		cohc_chan_param(cohc)->ctrl_lli_chained,
 994		ctrl_last);
 995	if (ret)
 996		goto err;
 997
 998	COH_DBG(coh901318_list_print(cohc, lli));
 999
1000	/* Pick a descriptor to handle this transfer */
1001	cohd = coh901318_desc_get(cohc);
1002	cohd->lli = lli;
1003	cohd->flags = flags;
1004	cohd->desc.tx_submit = coh901318_tx_submit;
1005
1006	spin_unlock_irqrestore(&cohc->lock, flg);
1007
1008	return &cohd->desc;
1009 err:
1010	spin_unlock_irqrestore(&cohc->lock, flg);
1011	return NULL;
1012}
1013
1014static struct dma_async_tx_descriptor *
1015coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
1016			unsigned int sg_len, enum dma_transfer_direction direction,
1017			unsigned long flags, void *context)
1018{
1019	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1020	struct coh901318_lli *lli;
1021	struct coh901318_desc *cohd;
1022	const struct coh901318_params *params;
1023	struct scatterlist *sg;
1024	int len = 0;
1025	int size;
1026	int i;
1027	u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
1028	u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
1029	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
1030	u32 config;
1031	unsigned long flg;
1032	int ret;
1033
1034	if (!sgl)
1035		goto out;
1036	if (sg_dma_len(sgl) == 0)
1037		goto out;
1038
1039	spin_lock_irqsave(&cohc->lock, flg);
1040
1041	dev_vdbg(COHC_2_DEV(cohc), "[%s] sg_len %d dir %d\n",
1042		 __func__, sg_len, direction);
1043
1044	if (flags & DMA_PREP_INTERRUPT)
1045		/* Trigger interrupt after last lli */
1046		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
1047
1048	params = cohc_chan_param(cohc);
1049	config = params->config;
1050	/*
1051	 * Add runtime-specific control on top, make
1052	 * sure the bits you set per peripheral channel are
1053	 * cleared in the default config from the platform.
1054	 */
1055	ctrl_chained |= cohc->runtime_ctrl;
1056	ctrl_last |= cohc->runtime_ctrl;
1057	ctrl |= cohc->runtime_ctrl;
1058
1059	if (direction == DMA_MEM_TO_DEV) {
1060		u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
1061			COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;
1062
1063		config |= COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY;
1064		ctrl_chained |= tx_flags;
1065		ctrl_last |= tx_flags;
1066		ctrl |= tx_flags;
1067	} else if (direction == DMA_DEV_TO_MEM) {
1068		u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
1069			COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;
1070
1071		config |= COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY;
1072		ctrl_chained |= rx_flags;
1073		ctrl_last |= rx_flags;
1074		ctrl |= rx_flags;
1075	} else
1076		goto err_direction;
1077
1078	/* The dma only supports transmitting packages up to
1079	 * MAX_DMA_PACKET_SIZE. Calculate to total number of
1080	 * dma elemts required to send the entire sg list
1081	 */
1082	for_each_sg(sgl, sg, sg_len, i) {
1083		unsigned int factor;
1084		size = sg_dma_len(sg);
1085
1086		if (size <= MAX_DMA_PACKET_SIZE) {
1087			len++;
1088			continue;
1089		}
1090
1091		factor = size >> MAX_DMA_PACKET_SIZE_SHIFT;
1092		if ((factor << MAX_DMA_PACKET_SIZE_SHIFT) < size)
1093			factor++;
1094
1095		len += factor;
1096	}
1097
1098	pr_debug("Allocate %d lli:s for this transfer\n", len);
1099	lli = coh901318_lli_alloc(&cohc->base->pool, len);
1100
1101	if (lli == NULL)
1102		goto err_dma_alloc;
1103
1104	/* initiate allocated lli list */
1105	ret = coh901318_lli_fill_sg(&cohc->base->pool, lli, sgl, sg_len,
1106				    cohc_dev_addr(cohc),
1107				    ctrl_chained,
1108				    ctrl,
1109				    ctrl_last,
1110				    direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
1111	if (ret)
1112		goto err_lli_fill;
1113
1114
1115	COH_DBG(coh901318_list_print(cohc, lli));
1116
1117	/* Pick a descriptor to handle this transfer */
1118	cohd = coh901318_desc_get(cohc);
1119	cohd->head_config = config;
1120	/*
1121	 * Set the default head ctrl for the channel to the one from the
1122	 * lli, things may have changed due to odd buffer alignment
1123	 * etc.
1124	 */
1125	cohd->head_ctrl = lli->control;
1126	cohd->dir = direction;
1127	cohd->flags = flags;
1128	cohd->desc.tx_submit = coh901318_tx_submit;
1129	cohd->lli = lli;
1130
1131	spin_unlock_irqrestore(&cohc->lock, flg);
1132
1133	return &cohd->desc;
1134 err_lli_fill:
1135 err_dma_alloc:
1136 err_direction:
1137	spin_unlock_irqrestore(&cohc->lock, flg);
1138 out:
1139	return NULL;
1140}
1141
1142static enum dma_status
1143coh901318_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
1144		 struct dma_tx_state *txstate)
1145{
1146	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1147	enum dma_status ret;
1148
1149	ret = dma_cookie_status(chan, cookie, txstate);
1150	/* FIXME: should be conditional on ret != DMA_SUCCESS? */
1151	dma_set_residue(txstate, coh901318_get_bytes_left(chan));
1152
1153	if (ret == DMA_IN_PROGRESS && cohc->stopped)
1154		ret = DMA_PAUSED;
1155
1156	return ret;
1157}
1158
1159static void
1160coh901318_issue_pending(struct dma_chan *chan)
1161{
1162	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1163	unsigned long flags;
1164
1165	spin_lock_irqsave(&cohc->lock, flags);
1166
1167	/*
1168	 * Busy means that pending jobs are already being processed,
1169	 * and then there is no point in starting the queue: the
1170	 * terminal count interrupt on the channel will take the next
1171	 * job on the queue and execute it anyway.
1172	 */
1173	if (!cohc->busy)
1174		coh901318_queue_start(cohc);
1175
1176	spin_unlock_irqrestore(&cohc->lock, flags);
1177}
1178
1179/*
1180 * Here we wrap in the runtime dma control interface
1181 */
1182struct burst_table {
1183	int burst_8bit;
1184	int burst_16bit;
1185	int burst_32bit;
1186	u32 reg;
1187};
1188
1189static const struct burst_table burst_sizes[] = {
1190	{
1191		.burst_8bit = 64,
1192		.burst_16bit = 32,
1193		.burst_32bit = 16,
1194		.reg = COH901318_CX_CTRL_BURST_COUNT_64_BYTES,
1195	},
1196	{
1197		.burst_8bit = 48,
1198		.burst_16bit = 24,
1199		.burst_32bit = 12,
1200		.reg = COH901318_CX_CTRL_BURST_COUNT_48_BYTES,
1201	},
1202	{
1203		.burst_8bit = 32,
1204		.burst_16bit = 16,
1205		.burst_32bit = 8,
1206		.reg = COH901318_CX_CTRL_BURST_COUNT_32_BYTES,
1207	},
1208	{
1209		.burst_8bit = 16,
1210		.burst_16bit = 8,
1211		.burst_32bit = 4,
1212		.reg = COH901318_CX_CTRL_BURST_COUNT_16_BYTES,
1213	},
1214	{
1215		.burst_8bit = 8,
1216		.burst_16bit = 4,
1217		.burst_32bit = 2,
1218		.reg = COH901318_CX_CTRL_BURST_COUNT_8_BYTES,
1219	},
1220	{
1221		.burst_8bit = 4,
1222		.burst_16bit = 2,
1223		.burst_32bit = 1,
1224		.reg = COH901318_CX_CTRL_BURST_COUNT_4_BYTES,
1225	},
1226	{
1227		.burst_8bit = 2,
1228		.burst_16bit = 1,
1229		.burst_32bit = 0,
1230		.reg = COH901318_CX_CTRL_BURST_COUNT_2_BYTES,
1231	},
1232	{
1233		.burst_8bit = 1,
1234		.burst_16bit = 0,
1235		.burst_32bit = 0,
1236		.reg = COH901318_CX_CTRL_BURST_COUNT_1_BYTE,
1237	},
1238};
1239
1240static void coh901318_dma_set_runtimeconfig(struct dma_chan *chan,
1241			struct dma_slave_config *config)
1242{
1243	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1244	dma_addr_t addr;
1245	enum dma_slave_buswidth addr_width;
1246	u32 maxburst;
1247	u32 runtime_ctrl = 0;
1248	int i = 0;
1249
1250	/* We only support mem to per or per to mem transfers */
1251	if (config->direction == DMA_DEV_TO_MEM) {
1252		addr = config->src_addr;
1253		addr_width = config->src_addr_width;
1254		maxburst = config->src_maxburst;
1255	} else if (config->direction == DMA_MEM_TO_DEV) {
1256		addr = config->dst_addr;
1257		addr_width = config->dst_addr_width;
1258		maxburst = config->dst_maxburst;
1259	} else {
1260		dev_err(COHC_2_DEV(cohc), "illegal channel mode\n");
1261		return;
1262	}
1263
1264	dev_dbg(COHC_2_DEV(cohc), "configure channel for %d byte transfers\n",
1265		addr_width);
1266	switch (addr_width)  {
1267	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1268		runtime_ctrl |=
1269			COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS |
1270			COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS;
1271
1272		while (i < ARRAY_SIZE(burst_sizes)) {
1273			if (burst_sizes[i].burst_8bit <= maxburst)
1274				break;
1275			i++;
1276		}
1277
1278		break;
1279	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1280		runtime_ctrl |=
1281			COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS |
1282			COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS;
1283
1284		while (i < ARRAY_SIZE(burst_sizes)) {
1285			if (burst_sizes[i].burst_16bit <= maxburst)
1286				break;
1287			i++;
1288		}
1289
1290		break;
1291	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1292		/* Direction doesn't matter here, it's 32/32 bits */
1293		runtime_ctrl |=
1294			COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS |
1295			COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS;
1296
1297		while (i < ARRAY_SIZE(burst_sizes)) {
1298			if (burst_sizes[i].burst_32bit <= maxburst)
1299				break;
1300			i++;
1301		}
1302
1303		break;
1304	default:
1305		dev_err(COHC_2_DEV(cohc),
1306			"bad runtimeconfig: alien address width\n");
1307		return;
1308	}
1309
1310	runtime_ctrl |= burst_sizes[i].reg;
1311	dev_dbg(COHC_2_DEV(cohc),
1312		"selected burst size %d bytes for address width %d bytes, maxburst %d\n",
1313		burst_sizes[i].burst_8bit, addr_width, maxburst);
1314
1315	cohc->runtime_addr = addr;
1316	cohc->runtime_ctrl = runtime_ctrl;
1317}
1318
1319static int
1320coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
1321		  unsigned long arg)
1322{
1323	unsigned long flags;
1324	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1325	struct coh901318_desc *cohd;
1326	void __iomem *virtbase = cohc->base->virtbase;
1327
1328	if (cmd == DMA_SLAVE_CONFIG) {
1329		struct dma_slave_config *config =
1330			(struct dma_slave_config *) arg;
1331
1332		coh901318_dma_set_runtimeconfig(chan, config);
1333		return 0;
1334	  }
1335
1336	if (cmd == DMA_PAUSE) {
1337		coh901318_pause(chan);
1338		return 0;
1339	}
1340
1341	if (cmd == DMA_RESUME) {
1342		coh901318_resume(chan);
1343		return 0;
1344	}
1345
1346	if (cmd != DMA_TERMINATE_ALL)
1347		return -ENXIO;
1348
1349	/* The remainder of this function terminates the transfer */
1350	coh901318_pause(chan);
1351	spin_lock_irqsave(&cohc->lock, flags);
1352
1353	/* Clear any pending BE or TC interrupt */
1354	if (cohc->id < 32) {
1355		writel(1 << cohc->id, virtbase + COH901318_BE_INT_CLEAR1);
1356		writel(1 << cohc->id, virtbase + COH901318_TC_INT_CLEAR1);
1357	} else {
1358		writel(1 << (cohc->id - 32), virtbase +
1359		       COH901318_BE_INT_CLEAR2);
1360		writel(1 << (cohc->id - 32), virtbase +
1361		       COH901318_TC_INT_CLEAR2);
1362	}
1363
1364	enable_powersave(cohc);
1365
1366	while ((cohd = coh901318_first_active_get(cohc))) {
1367		/* release the lli allocation*/
1368		coh901318_lli_free(&cohc->base->pool, &cohd->lli);
1369
1370		/* return desc to free-list */
1371		coh901318_desc_remove(cohd);
1372		coh901318_desc_free(cohc, cohd);
1373	}
1374
1375	while ((cohd = coh901318_first_queued(cohc))) {
1376		/* release the lli allocation*/
1377		coh901318_lli_free(&cohc->base->pool, &cohd->lli);
1378
1379		/* return desc to free-list */
1380		coh901318_desc_remove(cohd);
1381		coh901318_desc_free(cohc, cohd);
1382	}
1383
1384
1385	cohc->nbr_active_done = 0;
1386	cohc->busy = 0;
1387
1388	spin_unlock_irqrestore(&cohc->lock, flags);
1389
1390	return 0;
1391}
1392
1393void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
1394			 struct coh901318_base *base)
1395{
1396	int chans_i;
1397	int i = 0;
1398	struct coh901318_chan *cohc;
1399
1400	INIT_LIST_HEAD(&dma->channels);
1401
1402	for (chans_i = 0; pick_chans[chans_i] != -1; chans_i += 2) {
1403		for (i = pick_chans[chans_i]; i <= pick_chans[chans_i+1]; i++) {
1404			cohc = &base->chans[i];
1405
1406			cohc->base = base;
1407			cohc->chan.device = dma;
1408			cohc->id = i;
1409
1410			/* TODO: do we really need this lock if only one
1411			 * client is connected to each channel?
1412			 */
1413
1414			spin_lock_init(&cohc->lock);
1415
1416			cohc->nbr_active_done = 0;
1417			cohc->busy = 0;
1418			INIT_LIST_HEAD(&cohc->free);
1419			INIT_LIST_HEAD(&cohc->active);
1420			INIT_LIST_HEAD(&cohc->queue);
1421
1422			tasklet_init(&cohc->tasklet, dma_tasklet,
1423				     (unsigned long) cohc);
1424
1425			list_add_tail(&cohc->chan.device_node,
1426				      &dma->channels);
1427		}
1428	}
1429}
1430
1431static int __init coh901318_probe(struct platform_device *pdev)
1432{
1433	int err = 0;
1434	struct coh901318_platform *pdata;
1435	struct coh901318_base *base;
1436	int irq;
1437	struct resource *io;
1438
1439	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1440	if (!io)
1441		goto err_get_resource;
1442
1443	/* Map DMA controller registers to virtual memory */
1444	if (request_mem_region(io->start,
1445			       resource_size(io),
1446			       pdev->dev.driver->name) == NULL) {
1447		err = -EBUSY;
1448		goto err_request_mem;
1449	}
1450
1451	pdata = pdev->dev.platform_data;
1452	if (!pdata)
1453		goto err_no_platformdata;
1454
1455	base = kmalloc(ALIGN(sizeof(struct coh901318_base), 4) +
1456		       pdata->max_channels *
1457		       sizeof(struct coh901318_chan),
1458		       GFP_KERNEL);
1459	if (!base)
1460		goto err_alloc_coh_dma_channels;
1461
1462	base->chans = ((void *)base) + ALIGN(sizeof(struct coh901318_base), 4);
1463
1464	base->virtbase = ioremap(io->start, resource_size(io));
1465	if (!base->virtbase) {
1466		err = -ENOMEM;
1467		goto err_no_ioremap;
1468	}
1469
1470	base->dev = &pdev->dev;
1471	base->platform = pdata;
1472	spin_lock_init(&base->pm.lock);
1473	base->pm.started_channels = 0;
1474
1475	COH901318_DEBUGFS_ASSIGN(debugfs_dma_base, base);
1476
1477	platform_set_drvdata(pdev, base);
1478
1479	irq = platform_get_irq(pdev, 0);
1480	if (irq < 0)
1481		goto err_no_irq;
1482
1483	err = request_irq(irq, dma_irq_handler, IRQF_DISABLED,
1484			  "coh901318", base);
1485	if (err) {
1486		dev_crit(&pdev->dev,
1487			 "Cannot allocate IRQ for DMA controller!\n");
1488		goto err_request_irq;
1489	}
1490
1491	err = coh901318_pool_create(&base->pool, &pdev->dev,
1492				    sizeof(struct coh901318_lli),
1493				    32);
1494	if (err)
1495		goto err_pool_create;
1496
1497	/* init channels for device transfers */
1498	coh901318_base_init(&base->dma_slave,  base->platform->chans_slave,
1499			    base);
1500
1501	dma_cap_zero(base->dma_slave.cap_mask);
1502	dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
1503
1504	base->dma_slave.device_alloc_chan_resources = coh901318_alloc_chan_resources;
1505	base->dma_slave.device_free_chan_resources = coh901318_free_chan_resources;
1506	base->dma_slave.device_prep_slave_sg = coh901318_prep_slave_sg;
1507	base->dma_slave.device_tx_status = coh901318_tx_status;
1508	base->dma_slave.device_issue_pending = coh901318_issue_pending;
1509	base->dma_slave.device_control = coh901318_control;
1510	base->dma_slave.dev = &pdev->dev;
1511
1512	err = dma_async_device_register(&base->dma_slave);
1513
1514	if (err)
1515		goto err_register_slave;
1516
1517	/* init channels for memcpy */
1518	coh901318_base_init(&base->dma_memcpy, base->platform->chans_memcpy,
1519			    base);
1520
1521	dma_cap_zero(base->dma_memcpy.cap_mask);
1522	dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
1523
1524	base->dma_memcpy.device_alloc_chan_resources = coh901318_alloc_chan_resources;
1525	base->dma_memcpy.device_free_chan_resources = coh901318_free_chan_resources;
1526	base->dma_memcpy.device_prep_dma_memcpy = coh901318_prep_memcpy;
1527	base->dma_memcpy.device_tx_status = coh901318_tx_status;
1528	base->dma_memcpy.device_issue_pending = coh901318_issue_pending;
1529	base->dma_memcpy.device_control = coh901318_control;
1530	base->dma_memcpy.dev = &pdev->dev;
1531	/*
1532	 * This controller can only access address at even 32bit boundaries,
1533	 * i.e. 2^2
1534	 */
1535	base->dma_memcpy.copy_align = 2;
1536	err = dma_async_device_register(&base->dma_memcpy);
1537
1538	if (err)
1539		goto err_register_memcpy;
1540
1541	dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
1542		(u32) base->virtbase);
1543
1544	return err;
1545
1546 err_register_memcpy:
1547	dma_async_device_unregister(&base->dma_slave);
1548 err_register_slave:
1549	coh901318_pool_destroy(&base->pool);
1550 err_pool_create:
1551	free_irq(platform_get_irq(pdev, 0), base);
1552 err_request_irq:
1553 err_no_irq:
1554	iounmap(base->virtbase);
1555 err_no_ioremap:
1556	kfree(base);
1557 err_alloc_coh_dma_channels:
1558 err_no_platformdata:
1559	release_mem_region(pdev->resource->start,
1560			   resource_size(pdev->resource));
1561 err_request_mem:
1562 err_get_resource:
1563	return err;
1564}
1565
1566static int __exit coh901318_remove(struct platform_device *pdev)
1567{
1568	struct coh901318_base *base = platform_get_drvdata(pdev);
1569
1570	dma_async_device_unregister(&base->dma_memcpy);
1571	dma_async_device_unregister(&base->dma_slave);
1572	coh901318_pool_destroy(&base->pool);
1573	free_irq(platform_get_irq(pdev, 0), base);
1574	iounmap(base->virtbase);
1575	kfree(base);
1576	release_mem_region(pdev->resource->start,
1577			   resource_size(pdev->resource));
1578	return 0;
1579}
1580
1581
1582static struct platform_driver coh901318_driver = {
1583	.remove = __exit_p(coh901318_remove),
1584	.driver = {
1585		.name	= "coh901318",
1586	},
1587};
1588
1589int __init coh901318_init(void)
1590{
1591	return platform_driver_probe(&coh901318_driver, coh901318_probe);
1592}
1593subsys_initcall(coh901318_init);
1594
1595void __exit coh901318_exit(void)
1596{
1597	platform_driver_unregister(&coh901318_driver);
1598}
1599module_exit(coh901318_exit);
1600
1601MODULE_LICENSE("GPL");
1602MODULE_AUTHOR("Per Friden");