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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * linux/arch/arm/plat-omap/dma.c
  4 *
  5 * Copyright (C) 2003 - 2008 Nokia Corporation
  6 * Author: Juha Yrjölä <juha.yrjola@nokia.com>
  7 * DMA channel linking for 1610 by Samuel Ortiz <samuel.ortiz@nokia.com>
  8 * Graphics DMA and LCD DMA graphics tranformations
  9 * by Imre Deak <imre.deak@nokia.com>
 10 * OMAP2/3 support Copyright (C) 2004-2007 Texas Instruments, Inc.
 11 * Merged to support both OMAP1 and OMAP2 by Tony Lindgren <tony@atomide.com>
 12 * Some functions based on earlier dma-omap.c Copyright (C) 2001 RidgeRun, Inc.
 13 *
 14 * Copyright (C) 2009 Texas Instruments
 15 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 16 *
 17 * Support functions for the OMAP internal DMA channels.
 18 *
 19 * Copyright (C) 2010 Texas Instruments Incorporated - https://www.ti.com/
 20 * Converted DMA library into DMA platform driver.
 21 *	- G, Manjunath Kondaiah <manjugk@ti.com>
 22 */
 23
 24#include <linux/module.h>
 25#include <linux/init.h>
 26#include <linux/sched.h>
 27#include <linux/spinlock.h>
 28#include <linux/errno.h>
 29#include <linux/interrupt.h>
 30#include <linux/irq.h>
 31#include <linux/io.h>
 32#include <linux/slab.h>
 33#include <linux/delay.h>
 34
 35#include <linux/omap-dma.h>
 36
 37#include <linux/soc/ti/omap1-io.h>
 38#include <linux/soc/ti/omap1-soc.h>
 39
 40#include "tc.h"
 41
 42/*
 43 * MAX_LOGICAL_DMA_CH_COUNT: the maximum number of logical DMA
 44 * channels that an instance of the SDMA IP block can support.  Used
 45 * to size arrays.  (The actual maximum on a particular SoC may be less
 46 * than this -- for example, OMAP1 SDMA instances only support 17 logical
 47 * DMA channels.)
 48 */
 49#define MAX_LOGICAL_DMA_CH_COUNT		32
 50
 51#undef DEBUG
 52
 53#define OMAP_DMA_ACTIVE			0x01
 54
 55#define OMAP_FUNC_MUX_ARM_BASE		(0xfffe1000 + 0xec)
 56
 57static struct omap_system_dma_plat_info *p;
 58static struct omap_dma_dev_attr *d;
 59static int enable_1510_mode;
 60static u32 errata;
 61
 62struct dma_link_info {
 63	int *linked_dmach_q;
 64	int no_of_lchs_linked;
 65
 66	int q_count;
 67	int q_tail;
 68	int q_head;
 69
 70	int chain_state;
 71	int chain_mode;
 72
 73};
 74
 75static int dma_lch_count;
 76static int dma_chan_count;
 77static int omap_dma_reserve_channels;
 78
 79static DEFINE_SPINLOCK(dma_chan_lock);
 80static struct omap_dma_lch *dma_chan;
 81
 82static inline void omap_disable_channel_irq(int lch)
 83{
 84	/* disable channel interrupts */
 85	p->dma_write(0, CICR, lch);
 86	/* Clear CSR */
 87	p->dma_read(CSR, lch);
 88}
 89
 90static inline void set_gdma_dev(int req, int dev)
 91{
 92	u32 reg = OMAP_FUNC_MUX_ARM_BASE + ((req - 1) / 5) * 4;
 93	int shift = ((req - 1) % 5) * 6;
 94	u32 l;
 95
 96	l = omap_readl(reg);
 97	l &= ~(0x3f << shift);
 98	l |= (dev - 1) << shift;
 99	omap_writel(l, reg);
100}
101
102#if IS_ENABLED(CONFIG_FB_OMAP)
103void omap_set_dma_priority(int lch, int dst_port, int priority)
104{
105	unsigned long reg;
106	u32 l;
107
108	if (dma_omap1()) {
109		switch (dst_port) {
110		case OMAP_DMA_PORT_OCP_T1:	/* FFFECC00 */
111			reg = OMAP_TC_OCPT1_PRIOR;
112			break;
113		case OMAP_DMA_PORT_OCP_T2:	/* FFFECCD0 */
114			reg = OMAP_TC_OCPT2_PRIOR;
115			break;
116		case OMAP_DMA_PORT_EMIFF:	/* FFFECC08 */
117			reg = OMAP_TC_EMIFF_PRIOR;
118			break;
119		case OMAP_DMA_PORT_EMIFS:	/* FFFECC04 */
120			reg = OMAP_TC_EMIFS_PRIOR;
121			break;
122		default:
123			BUG();
124			return;
125		}
126		l = omap_readl(reg);
127		l &= ~(0xf << 8);
128		l |= (priority & 0xf) << 8;
129		omap_writel(l, reg);
130	}
131}
132EXPORT_SYMBOL(omap_set_dma_priority);
133#endif
134
135#if IS_ENABLED(CONFIG_USB_OMAP)
136#ifdef CONFIG_ARCH_OMAP15XX
137/* Returns 1 if the DMA module is in OMAP1510-compatible mode, 0 otherwise */
138static int omap_dma_in_1510_mode(void)
139{
140	return enable_1510_mode;
141}
142#else
143#define omap_dma_in_1510_mode()		0
144#endif
145
146void omap_set_dma_transfer_params(int lch, int data_type, int elem_count,
147				  int frame_count, int sync_mode,
148				  int dma_trigger, int src_or_dst_synch)
149{
150	u32 l;
151	u16 ccr;
152
153	l = p->dma_read(CSDP, lch);
154	l &= ~0x03;
155	l |= data_type;
156	p->dma_write(l, CSDP, lch);
157
158	ccr = p->dma_read(CCR, lch);
159	ccr &= ~(1 << 5);
160	if (sync_mode == OMAP_DMA_SYNC_FRAME)
161		ccr |= 1 << 5;
162	p->dma_write(ccr, CCR, lch);
163
164	ccr = p->dma_read(CCR2, lch);
165	ccr &= ~(1 << 2);
166	if (sync_mode == OMAP_DMA_SYNC_BLOCK)
167		ccr |= 1 << 2;
168	p->dma_write(ccr, CCR2, lch);
169	p->dma_write(elem_count, CEN, lch);
170	p->dma_write(frame_count, CFN, lch);
171}
172EXPORT_SYMBOL(omap_set_dma_transfer_params);
173
174void omap_set_dma_channel_mode(int lch, enum omap_dma_channel_mode mode)
175{
176	if (!dma_omap15xx()) {
177		u32 l;
178
179		l = p->dma_read(LCH_CTRL, lch);
180		l &= ~0x7;
181		l |= mode;
182		p->dma_write(l, LCH_CTRL, lch);
183	}
184}
185EXPORT_SYMBOL(omap_set_dma_channel_mode);
186
187/* Note that src_port is only for omap1 */
188void omap_set_dma_src_params(int lch, int src_port, int src_amode,
189			     unsigned long src_start,
190			     int src_ei, int src_fi)
191{
192	u32 l;
193	u16 w;
194
195	w = p->dma_read(CSDP, lch);
196	w &= ~(0x1f << 2);
197	w |= src_port << 2;
198	p->dma_write(w, CSDP, lch);
199
200	l = p->dma_read(CCR, lch);
201	l &= ~(0x03 << 12);
202	l |= src_amode << 12;
203	p->dma_write(l, CCR, lch);
204
205	p->dma_write(src_start, CSSA, lch);
206
207	p->dma_write(src_ei, CSEI, lch);
208	p->dma_write(src_fi, CSFI, lch);
209}
210EXPORT_SYMBOL(omap_set_dma_src_params);
211
212void omap_set_dma_src_data_pack(int lch, int enable)
213{
214	u32 l;
215
216	l = p->dma_read(CSDP, lch);
217	l &= ~(1 << 6);
218	if (enable)
219		l |= (1 << 6);
220	p->dma_write(l, CSDP, lch);
221}
222EXPORT_SYMBOL(omap_set_dma_src_data_pack);
223
224void omap_set_dma_src_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
225{
226	unsigned int burst = 0;
227	u32 l;
228
229	l = p->dma_read(CSDP, lch);
230	l &= ~(0x03 << 7);
231
232	switch (burst_mode) {
233	case OMAP_DMA_DATA_BURST_DIS:
234		break;
235	case OMAP_DMA_DATA_BURST_4:
236		burst = 0x2;
237		break;
238	case OMAP_DMA_DATA_BURST_8:
239		/*
240		 * not supported by current hardware on OMAP1
241		 * w |= (0x03 << 7);
242		 */
243		fallthrough;
244	case OMAP_DMA_DATA_BURST_16:
245		/* OMAP1 don't support burst 16 */
246		fallthrough;
247	default:
248		BUG();
249	}
250
251	l |= (burst << 7);
252	p->dma_write(l, CSDP, lch);
253}
254EXPORT_SYMBOL(omap_set_dma_src_burst_mode);
255
256/* Note that dest_port is only for OMAP1 */
257void omap_set_dma_dest_params(int lch, int dest_port, int dest_amode,
258			      unsigned long dest_start,
259			      int dst_ei, int dst_fi)
260{
261	u32 l;
262
263	l = p->dma_read(CSDP, lch);
264	l &= ~(0x1f << 9);
265	l |= dest_port << 9;
266	p->dma_write(l, CSDP, lch);
267
268	l = p->dma_read(CCR, lch);
269	l &= ~(0x03 << 14);
270	l |= dest_amode << 14;
271	p->dma_write(l, CCR, lch);
272
273	p->dma_write(dest_start, CDSA, lch);
274
275	p->dma_write(dst_ei, CDEI, lch);
276	p->dma_write(dst_fi, CDFI, lch);
277}
278EXPORT_SYMBOL(omap_set_dma_dest_params);
279
280void omap_set_dma_dest_data_pack(int lch, int enable)
281{
282	u32 l;
283
284	l = p->dma_read(CSDP, lch);
285	l &= ~(1 << 13);
286	if (enable)
287		l |= 1 << 13;
288	p->dma_write(l, CSDP, lch);
289}
290EXPORT_SYMBOL(omap_set_dma_dest_data_pack);
291
292void omap_set_dma_dest_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
293{
294	unsigned int burst = 0;
295	u32 l;
296
297	l = p->dma_read(CSDP, lch);
298	l &= ~(0x03 << 14);
299
300	switch (burst_mode) {
301	case OMAP_DMA_DATA_BURST_DIS:
302		break;
303	case OMAP_DMA_DATA_BURST_4:
304		burst = 0x2;
305		break;
306	case OMAP_DMA_DATA_BURST_8:
307		burst = 0x3;
308		break;
309	case OMAP_DMA_DATA_BURST_16:
310		/* OMAP1 don't support burst 16 */
311		fallthrough;
312	default:
313		printk(KERN_ERR "Invalid DMA burst mode\n");
314		BUG();
315		return;
316	}
317	l |= (burst << 14);
318	p->dma_write(l, CSDP, lch);
319}
320EXPORT_SYMBOL(omap_set_dma_dest_burst_mode);
321
322static inline void omap_enable_channel_irq(int lch)
323{
324	/* Clear CSR */
325	p->dma_read(CSR, lch);
326
327	/* Enable some nice interrupts. */
328	p->dma_write(dma_chan[lch].enabled_irqs, CICR, lch);
329}
330
331void omap_disable_dma_irq(int lch, u16 bits)
332{
333	dma_chan[lch].enabled_irqs &= ~bits;
334}
335EXPORT_SYMBOL(omap_disable_dma_irq);
336
337static inline void enable_lnk(int lch)
338{
339	u32 l;
340
341	l = p->dma_read(CLNK_CTRL, lch);
342
343	l &= ~(1 << 14);
344
345	/* Set the ENABLE_LNK bits */
346	if (dma_chan[lch].next_lch != -1)
347		l = dma_chan[lch].next_lch | (1 << 15);
348
349	p->dma_write(l, CLNK_CTRL, lch);
350}
351
352static inline void disable_lnk(int lch)
353{
354	u32 l;
355
356	l = p->dma_read(CLNK_CTRL, lch);
357
358	/* Disable interrupts */
359	omap_disable_channel_irq(lch);
360
361	/* Set the STOP_LNK bit */
362	l |= 1 << 14;
363
364	p->dma_write(l, CLNK_CTRL, lch);
365	dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
366}
367#endif
368
369int omap_request_dma(int dev_id, const char *dev_name,
370		     void (*callback)(int lch, u16 ch_status, void *data),
371		     void *data, int *dma_ch_out)
372{
373	int ch, free_ch = -1;
374	unsigned long flags;
375	struct omap_dma_lch *chan;
376
377	WARN(strcmp(dev_name, "DMA engine"), "Using deprecated platform DMA API - please update to DMA engine");
378
379	spin_lock_irqsave(&dma_chan_lock, flags);
380	for (ch = 0; ch < dma_chan_count; ch++) {
381		if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
382			free_ch = ch;
383			/* Exit after first free channel found */
384			break;
385		}
386	}
387	if (free_ch == -1) {
388		spin_unlock_irqrestore(&dma_chan_lock, flags);
389		return -EBUSY;
390	}
391	chan = dma_chan + free_ch;
392	chan->dev_id = dev_id;
393
394	if (p->clear_lch_regs)
395		p->clear_lch_regs(free_ch);
396
397	spin_unlock_irqrestore(&dma_chan_lock, flags);
398
399	chan->dev_name = dev_name;
400	chan->callback = callback;
401	chan->data = data;
402	chan->flags = 0;
403
404	chan->enabled_irqs = OMAP_DMA_DROP_IRQ | OMAP_DMA_BLOCK_IRQ;
405
406	chan->enabled_irqs |= OMAP1_DMA_TOUT_IRQ;
407
408	if (dma_omap16xx()) {
409		/* If the sync device is set, configure it dynamically. */
410		if (dev_id != 0) {
411			set_gdma_dev(free_ch + 1, dev_id);
412			dev_id = free_ch + 1;
413		}
414		/*
415		 * Disable the 1510 compatibility mode and set the sync device
416		 * id.
417		 */
418		p->dma_write(dev_id | (1 << 10), CCR, free_ch);
419	} else {
420		p->dma_write(dev_id, CCR, free_ch);
421	}
422
423	*dma_ch_out = free_ch;
424
425	return 0;
426}
427EXPORT_SYMBOL(omap_request_dma);
428
429void omap_free_dma(int lch)
430{
431	unsigned long flags;
432
433	if (dma_chan[lch].dev_id == -1) {
434		pr_err("omap_dma: trying to free unallocated DMA channel %d\n",
435		       lch);
436		return;
437	}
438
439	/* Disable all DMA interrupts for the channel. */
440	omap_disable_channel_irq(lch);
441
442	/* Make sure the DMA transfer is stopped. */
443	p->dma_write(0, CCR, lch);
444
445	spin_lock_irqsave(&dma_chan_lock, flags);
446	dma_chan[lch].dev_id = -1;
447	dma_chan[lch].next_lch = -1;
448	dma_chan[lch].callback = NULL;
449	spin_unlock_irqrestore(&dma_chan_lock, flags);
450}
451EXPORT_SYMBOL(omap_free_dma);
452
453/*
454 * Clears any DMA state so the DMA engine is ready to restart with new buffers
455 * through omap_start_dma(). Any buffers in flight are discarded.
456 */
457static void omap_clear_dma(int lch)
458{
459	unsigned long flags;
460
461	local_irq_save(flags);
462	p->clear_dma(lch);
463	local_irq_restore(flags);
464}
465
466#if IS_ENABLED(CONFIG_USB_OMAP)
467void omap_start_dma(int lch)
468{
469	u32 l;
470
471	/*
472	 * The CPC/CDAC register needs to be initialized to zero
473	 * before starting dma transfer.
474	 */
475	if (dma_omap15xx())
476		p->dma_write(0, CPC, lch);
477	else
478		p->dma_write(0, CDAC, lch);
479
480	if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
481		int next_lch, cur_lch;
482		char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
483
484		/* Set the link register of the first channel */
485		enable_lnk(lch);
486
487		memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
488		dma_chan_link_map[lch] = 1;
489
490		cur_lch = dma_chan[lch].next_lch;
491		do {
492			next_lch = dma_chan[cur_lch].next_lch;
493
494			/* The loop case: we've been here already */
495			if (dma_chan_link_map[cur_lch])
496				break;
497			/* Mark the current channel */
498			dma_chan_link_map[cur_lch] = 1;
499
500			enable_lnk(cur_lch);
501			omap_enable_channel_irq(cur_lch);
502
503			cur_lch = next_lch;
504		} while (next_lch != -1);
505	} else if (IS_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS))
506		p->dma_write(lch, CLNK_CTRL, lch);
507
508	omap_enable_channel_irq(lch);
509
510	l = p->dma_read(CCR, lch);
511
512	if (IS_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING))
513			l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
514	l |= OMAP_DMA_CCR_EN;
515
516	/*
517	 * As dma_write() uses IO accessors which are weakly ordered, there
518	 * is no guarantee that data in coherent DMA memory will be visible
519	 * to the DMA device.  Add a memory barrier here to ensure that any
520	 * such data is visible prior to enabling DMA.
521	 */
522	mb();
523	p->dma_write(l, CCR, lch);
524
525	dma_chan[lch].flags |= OMAP_DMA_ACTIVE;
526}
527EXPORT_SYMBOL(omap_start_dma);
528
529void omap_stop_dma(int lch)
530{
531	u32 l;
532
533	/* Disable all interrupts on the channel */
534	omap_disable_channel_irq(lch);
535
536	l = p->dma_read(CCR, lch);
537	if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&
538			(l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
539		int i = 0;
540		u32 sys_cf;
541
542		/* Configure No-Standby */
543		l = p->dma_read(OCP_SYSCONFIG, lch);
544		sys_cf = l;
545		l &= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
546		l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
547		p->dma_write(l , OCP_SYSCONFIG, 0);
548
549		l = p->dma_read(CCR, lch);
550		l &= ~OMAP_DMA_CCR_EN;
551		p->dma_write(l, CCR, lch);
552
553		/* Wait for sDMA FIFO drain */
554		l = p->dma_read(CCR, lch);
555		while (i < 100 && (l & (OMAP_DMA_CCR_RD_ACTIVE |
556					OMAP_DMA_CCR_WR_ACTIVE))) {
557			udelay(5);
558			i++;
559			l = p->dma_read(CCR, lch);
560		}
561		if (i >= 100)
562			pr_err("DMA drain did not complete on lch %d\n", lch);
563		/* Restore OCP_SYSCONFIG */
564		p->dma_write(sys_cf, OCP_SYSCONFIG, lch);
565	} else {
566		l &= ~OMAP_DMA_CCR_EN;
567		p->dma_write(l, CCR, lch);
568	}
569
570	/*
571	 * Ensure that data transferred by DMA is visible to any access
572	 * after DMA has been disabled.  This is important for coherent
573	 * DMA regions.
574	 */
575	mb();
576
577	if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
578		int next_lch, cur_lch = lch;
579		char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
580
581		memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
582		do {
583			/* The loop case: we've been here already */
584			if (dma_chan_link_map[cur_lch])
585				break;
586			/* Mark the current channel */
587			dma_chan_link_map[cur_lch] = 1;
588
589			disable_lnk(cur_lch);
590
591			next_lch = dma_chan[cur_lch].next_lch;
592			cur_lch = next_lch;
593		} while (next_lch != -1);
594	}
595
596	dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
597}
598EXPORT_SYMBOL(omap_stop_dma);
599
600/*
601 * Allows changing the DMA callback function or data. This may be needed if
602 * the driver shares a single DMA channel for multiple dma triggers.
603 */
604/*
605 * Returns current physical source address for the given DMA channel.
606 * If the channel is running the caller must disable interrupts prior calling
607 * this function and process the returned value before re-enabling interrupt to
608 * prevent races with the interrupt handler. Note that in continuous mode there
609 * is a chance for CSSA_L register overflow between the two reads resulting
610 * in incorrect return value.
611 */
612dma_addr_t omap_get_dma_src_pos(int lch)
613{
614	dma_addr_t offset = 0;
615
616	if (dma_omap15xx())
617		offset = p->dma_read(CPC, lch);
618	else
619		offset = p->dma_read(CSAC, lch);
620
621	if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0)
622		offset = p->dma_read(CSAC, lch);
623
624	if (!dma_omap15xx()) {
625		/*
626		 * CDAC == 0 indicates that the DMA transfer on the channel has
627		 * not been started (no data has been transferred so far).
628		 * Return the programmed source start address in this case.
629		 */
630		if (likely(p->dma_read(CDAC, lch)))
631			offset = p->dma_read(CSAC, lch);
632		else
633			offset = p->dma_read(CSSA, lch);
634	}
635
636	offset |= (p->dma_read(CSSA, lch) & 0xFFFF0000);
637
638	return offset;
639}
640EXPORT_SYMBOL(omap_get_dma_src_pos);
641
642/*
643 * Returns current physical destination address for the given DMA channel.
644 * If the channel is running the caller must disable interrupts prior calling
645 * this function and process the returned value before re-enabling interrupt to
646 * prevent races with the interrupt handler. Note that in continuous mode there
647 * is a chance for CDSA_L register overflow between the two reads resulting
648 * in incorrect return value.
649 */
650dma_addr_t omap_get_dma_dst_pos(int lch)
651{
652	dma_addr_t offset = 0;
653
654	if (dma_omap15xx())
655		offset = p->dma_read(CPC, lch);
656	else
657		offset = p->dma_read(CDAC, lch);
658
659	/*
660	 * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
661	 * read before the DMA controller finished disabling the channel.
662	 */
663	if (!dma_omap15xx() && offset == 0) {
664		offset = p->dma_read(CDAC, lch);
665		/*
666		 * CDAC == 0 indicates that the DMA transfer on the channel has
667		 * not been started (no data has been transferred so far).
668		 * Return the programmed destination start address in this case.
669		 */
670		if (unlikely(!offset))
671			offset = p->dma_read(CDSA, lch);
672	}
673
674	offset |= (p->dma_read(CDSA, lch) & 0xFFFF0000);
675
676	return offset;
677}
678EXPORT_SYMBOL(omap_get_dma_dst_pos);
679
680int omap_get_dma_active_status(int lch)
681{
682	return (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN) != 0;
683}
684EXPORT_SYMBOL(omap_get_dma_active_status);
685#endif
686
687int omap_dma_running(void)
688{
689	int lch;
690
691	if (omap_lcd_dma_running())
692		return 1;
693
694	for (lch = 0; lch < dma_chan_count; lch++)
695		if (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN)
696			return 1;
697
698	return 0;
699}
700
701/*----------------------------------------------------------------------------*/
702
703static int omap1_dma_handle_ch(int ch)
704{
705	u32 csr;
706
707	if (enable_1510_mode && ch >= 6) {
708		csr = dma_chan[ch].saved_csr;
709		dma_chan[ch].saved_csr = 0;
710	} else
711		csr = p->dma_read(CSR, ch);
712	if (enable_1510_mode && ch <= 2 && (csr >> 7) != 0) {
713		dma_chan[ch + 6].saved_csr = csr >> 7;
714		csr &= 0x7f;
715	}
716	if ((csr & 0x3f) == 0)
717		return 0;
718	if (unlikely(dma_chan[ch].dev_id == -1)) {
719		pr_warn("Spurious interrupt from DMA channel %d (CSR %04x)\n",
720			ch, csr);
721		return 0;
722	}
723	if (unlikely(csr & OMAP1_DMA_TOUT_IRQ))
724		pr_warn("DMA timeout with device %d\n", dma_chan[ch].dev_id);
725	if (unlikely(csr & OMAP_DMA_DROP_IRQ))
726		pr_warn("DMA synchronization event drop occurred with device %d\n",
727			dma_chan[ch].dev_id);
728	if (likely(csr & OMAP_DMA_BLOCK_IRQ))
729		dma_chan[ch].flags &= ~OMAP_DMA_ACTIVE;
730	if (likely(dma_chan[ch].callback != NULL))
731		dma_chan[ch].callback(ch, csr, dma_chan[ch].data);
732
733	return 1;
734}
735
736static irqreturn_t omap1_dma_irq_handler(int irq, void *dev_id)
737{
738	int ch = ((int) dev_id) - 1;
739	int handled = 0;
740
741	for (;;) {
742		int handled_now = 0;
743
744		handled_now += omap1_dma_handle_ch(ch);
745		if (enable_1510_mode && dma_chan[ch + 6].saved_csr)
746			handled_now += omap1_dma_handle_ch(ch + 6);
747		if (!handled_now)
748			break;
749		handled += handled_now;
750	}
751
752	return handled ? IRQ_HANDLED : IRQ_NONE;
753}
754
755struct omap_system_dma_plat_info *omap_get_plat_info(void)
756{
757	return p;
758}
759EXPORT_SYMBOL_GPL(omap_get_plat_info);
760
761static int omap_system_dma_probe(struct platform_device *pdev)
762{
763	int ch, ret = 0;
764	int dma_irq;
765	char irq_name[4];
766
767	p = pdev->dev.platform_data;
768	if (!p) {
769		dev_err(&pdev->dev,
770			"%s: System DMA initialized without platform data\n",
771			__func__);
772		return -EINVAL;
773	}
774
775	d			= p->dma_attr;
776	errata			= p->errata;
777
778	if ((d->dev_caps & RESERVE_CHANNEL) && omap_dma_reserve_channels
779			&& (omap_dma_reserve_channels < d->lch_count))
780		d->lch_count	= omap_dma_reserve_channels;
781
782	dma_lch_count		= d->lch_count;
783	dma_chan_count		= dma_lch_count;
784	enable_1510_mode	= d->dev_caps & ENABLE_1510_MODE;
785
786	dma_chan = devm_kcalloc(&pdev->dev, dma_lch_count,
787				sizeof(*dma_chan), GFP_KERNEL);
788	if (!dma_chan)
789		return -ENOMEM;
790
791	for (ch = 0; ch < dma_chan_count; ch++) {
792		omap_clear_dma(ch);
793
794		dma_chan[ch].dev_id = -1;
795		dma_chan[ch].next_lch = -1;
796
797		if (ch >= 6 && enable_1510_mode)
798			continue;
799
800		/*
801		 * request_irq() doesn't like dev_id (ie. ch) being
802		 * zero, so we have to kludge around this.
803		 */
804		sprintf(&irq_name[0], "%d", ch);
805		dma_irq = platform_get_irq_byname(pdev, irq_name);
806
807		if (dma_irq < 0) {
808			ret = dma_irq;
809			goto exit_dma_irq_fail;
810		}
811
812		/* INT_DMA_LCD is handled in lcd_dma.c */
813		if (dma_irq == INT_DMA_LCD)
814			continue;
815
816		ret = request_irq(dma_irq,
817				omap1_dma_irq_handler, 0, "DMA",
818				(void *) (ch + 1));
819		if (ret != 0)
820			goto exit_dma_irq_fail;
821	}
822
823	/* reserve dma channels 0 and 1 in high security devices on 34xx */
824	if (d->dev_caps & HS_CHANNELS_RESERVED) {
825		pr_info("Reserving DMA channels 0 and 1 for HS ROM code\n");
826		dma_chan[0].dev_id = 0;
827		dma_chan[1].dev_id = 1;
828	}
829	p->show_dma_caps();
830	return 0;
831
832exit_dma_irq_fail:
833	return ret;
834}
835
836static void omap_system_dma_remove(struct platform_device *pdev)
837{
838	int dma_irq, irq_rel = 0;
839
840	for ( ; irq_rel < dma_chan_count; irq_rel++) {
841		dma_irq = platform_get_irq(pdev, irq_rel);
842		free_irq(dma_irq, (void *)(irq_rel + 1));
843	}
844}
845
846static struct platform_driver omap_system_dma_driver = {
847	.probe		= omap_system_dma_probe,
848	.remove_new	= omap_system_dma_remove,
849	.driver		= {
850		.name	= "omap_dma_system"
851	},
852};
853
854static int __init omap_system_dma_init(void)
855{
856	return platform_driver_register(&omap_system_dma_driver);
857}
858arch_initcall(omap_system_dma_init);
859
860static void __exit omap_system_dma_exit(void)
861{
862	platform_driver_unregister(&omap_system_dma_driver);
863}
864
865MODULE_DESCRIPTION("OMAP SYSTEM DMA DRIVER");
866MODULE_LICENSE("GPL");
867MODULE_AUTHOR("Texas Instruments Inc");
868
869/*
870 * Reserve the omap SDMA channels using cmdline bootarg
871 * "omap_dma_reserve_ch=". The valid range is 1 to 32
872 */
873static int __init omap_dma_cmdline_reserve_ch(char *str)
874{
875	if (get_option(&str, &omap_dma_reserve_channels) != 1)
876		omap_dma_reserve_channels = 0;
877	return 1;
878}
879
880__setup("omap_dma_reserve_ch=", omap_dma_cmdline_reserve_ch);
881
882