xref: /kernel/linux/linux-5.10/arch/arm/plat-omap/dma.c (revision 8c2ecf20)
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#ifdef CONFIG_ARCH_OMAP1
38#include <mach/soc.h>
39#endif
40
41/*
42 * MAX_LOGICAL_DMA_CH_COUNT: the maximum number of logical DMA
43 * channels that an instance of the SDMA IP block can support.  Used
44 * to size arrays.  (The actual maximum on a particular SoC may be less
45 * than this -- for example, OMAP1 SDMA instances only support 17 logical
46 * DMA channels.)
47 */
48#define MAX_LOGICAL_DMA_CH_COUNT		32
49
50#undef DEBUG
51
52#ifndef CONFIG_ARCH_OMAP1
53enum { DMA_CH_ALLOC_DONE, DMA_CH_PARAMS_SET_DONE, DMA_CH_STARTED,
54	DMA_CH_QUEUED, DMA_CH_NOTSTARTED, DMA_CH_PAUSED, DMA_CH_LINK_ENABLED
55};
56
57enum { DMA_CHAIN_STARTED, DMA_CHAIN_NOTSTARTED };
58#endif
59
60#define OMAP_DMA_ACTIVE			0x01
61#define OMAP2_DMA_CSR_CLEAR_MASK	0xffffffff
62
63#define OMAP_FUNC_MUX_ARM_BASE		(0xfffe1000 + 0xec)
64
65static struct omap_system_dma_plat_info *p;
66static struct omap_dma_dev_attr *d;
67static void omap_clear_dma(int lch);
68static int enable_1510_mode;
69static u32 errata;
70
71struct dma_link_info {
72	int *linked_dmach_q;
73	int no_of_lchs_linked;
74
75	int q_count;
76	int q_tail;
77	int q_head;
78
79	int chain_state;
80	int chain_mode;
81
82};
83
84static int dma_lch_count;
85static int dma_chan_count;
86static int omap_dma_reserve_channels;
87
88static spinlock_t dma_chan_lock;
89static struct omap_dma_lch *dma_chan;
90
91static inline void disable_lnk(int lch);
92static void omap_disable_channel_irq(int lch);
93static inline void omap_enable_channel_irq(int lch);
94
95#ifdef CONFIG_ARCH_OMAP15XX
96/* Returns 1 if the DMA module is in OMAP1510-compatible mode, 0 otherwise */
97static int omap_dma_in_1510_mode(void)
98{
99	return enable_1510_mode;
100}
101#else
102#define omap_dma_in_1510_mode()		0
103#endif
104
105#ifdef CONFIG_ARCH_OMAP1
106static inline void set_gdma_dev(int req, int dev)
107{
108	u32 reg = OMAP_FUNC_MUX_ARM_BASE + ((req - 1) / 5) * 4;
109	int shift = ((req - 1) % 5) * 6;
110	u32 l;
111
112	l = omap_readl(reg);
113	l &= ~(0x3f << shift);
114	l |= (dev - 1) << shift;
115	omap_writel(l, reg);
116}
117#else
118#define set_gdma_dev(req, dev)	do {} while (0)
119#define omap_readl(reg)		0
120#define omap_writel(val, reg)	do {} while (0)
121#endif
122
123#ifdef CONFIG_ARCH_OMAP1
124void omap_set_dma_priority(int lch, int dst_port, int priority)
125{
126	unsigned long reg;
127	u32 l;
128
129	if (dma_omap1()) {
130		switch (dst_port) {
131		case OMAP_DMA_PORT_OCP_T1:	/* FFFECC00 */
132			reg = OMAP_TC_OCPT1_PRIOR;
133			break;
134		case OMAP_DMA_PORT_OCP_T2:	/* FFFECCD0 */
135			reg = OMAP_TC_OCPT2_PRIOR;
136			break;
137		case OMAP_DMA_PORT_EMIFF:	/* FFFECC08 */
138			reg = OMAP_TC_EMIFF_PRIOR;
139			break;
140		case OMAP_DMA_PORT_EMIFS:	/* FFFECC04 */
141			reg = OMAP_TC_EMIFS_PRIOR;
142			break;
143		default:
144			BUG();
145			return;
146		}
147		l = omap_readl(reg);
148		l &= ~(0xf << 8);
149		l |= (priority & 0xf) << 8;
150		omap_writel(l, reg);
151	}
152}
153#endif
154
155#ifdef CONFIG_ARCH_OMAP2PLUS
156void omap_set_dma_priority(int lch, int dst_port, int priority)
157{
158	u32 ccr;
159
160	ccr = p->dma_read(CCR, lch);
161	if (priority)
162		ccr |= (1 << 6);
163	else
164		ccr &= ~(1 << 6);
165	p->dma_write(ccr, CCR, lch);
166}
167#endif
168EXPORT_SYMBOL(omap_set_dma_priority);
169
170void omap_set_dma_transfer_params(int lch, int data_type, int elem_count,
171				  int frame_count, int sync_mode,
172				  int dma_trigger, int src_or_dst_synch)
173{
174	u32 l;
175
176	l = p->dma_read(CSDP, lch);
177	l &= ~0x03;
178	l |= data_type;
179	p->dma_write(l, CSDP, lch);
180
181	if (dma_omap1()) {
182		u16 ccr;
183
184		ccr = p->dma_read(CCR, lch);
185		ccr &= ~(1 << 5);
186		if (sync_mode == OMAP_DMA_SYNC_FRAME)
187			ccr |= 1 << 5;
188		p->dma_write(ccr, CCR, lch);
189
190		ccr = p->dma_read(CCR2, lch);
191		ccr &= ~(1 << 2);
192		if (sync_mode == OMAP_DMA_SYNC_BLOCK)
193			ccr |= 1 << 2;
194		p->dma_write(ccr, CCR2, lch);
195	}
196
197	if (dma_omap2plus() && dma_trigger) {
198		u32 val;
199
200		val = p->dma_read(CCR, lch);
201
202		/* DMA_SYNCHRO_CONTROL_UPPER depends on the channel number */
203		val &= ~((1 << 23) | (3 << 19) | 0x1f);
204		val |= (dma_trigger & ~0x1f) << 14;
205		val |= dma_trigger & 0x1f;
206
207		if (sync_mode & OMAP_DMA_SYNC_FRAME)
208			val |= 1 << 5;
209		else
210			val &= ~(1 << 5);
211
212		if (sync_mode & OMAP_DMA_SYNC_BLOCK)
213			val |= 1 << 18;
214		else
215			val &= ~(1 << 18);
216
217		if (src_or_dst_synch == OMAP_DMA_DST_SYNC_PREFETCH) {
218			val &= ~(1 << 24);	/* dest synch */
219			val |= (1 << 23);	/* Prefetch */
220		} else if (src_or_dst_synch) {
221			val |= 1 << 24;		/* source synch */
222		} else {
223			val &= ~(1 << 24);	/* dest synch */
224		}
225		p->dma_write(val, CCR, lch);
226	}
227
228	p->dma_write(elem_count, CEN, lch);
229	p->dma_write(frame_count, CFN, lch);
230}
231EXPORT_SYMBOL(omap_set_dma_transfer_params);
232
233void omap_set_dma_channel_mode(int lch, enum omap_dma_channel_mode mode)
234{
235	if (dma_omap1() && !dma_omap15xx()) {
236		u32 l;
237
238		l = p->dma_read(LCH_CTRL, lch);
239		l &= ~0x7;
240		l |= mode;
241		p->dma_write(l, LCH_CTRL, lch);
242	}
243}
244EXPORT_SYMBOL(omap_set_dma_channel_mode);
245
246/* Note that src_port is only for omap1 */
247void omap_set_dma_src_params(int lch, int src_port, int src_amode,
248			     unsigned long src_start,
249			     int src_ei, int src_fi)
250{
251	u32 l;
252
253	if (dma_omap1()) {
254		u16 w;
255
256		w = p->dma_read(CSDP, lch);
257		w &= ~(0x1f << 2);
258		w |= src_port << 2;
259		p->dma_write(w, CSDP, lch);
260	}
261
262	l = p->dma_read(CCR, lch);
263	l &= ~(0x03 << 12);
264	l |= src_amode << 12;
265	p->dma_write(l, CCR, lch);
266
267	p->dma_write(src_start, CSSA, lch);
268
269	p->dma_write(src_ei, CSEI, lch);
270	p->dma_write(src_fi, CSFI, lch);
271}
272EXPORT_SYMBOL(omap_set_dma_src_params);
273
274void omap_set_dma_src_data_pack(int lch, int enable)
275{
276	u32 l;
277
278	l = p->dma_read(CSDP, lch);
279	l &= ~(1 << 6);
280	if (enable)
281		l |= (1 << 6);
282	p->dma_write(l, CSDP, lch);
283}
284EXPORT_SYMBOL(omap_set_dma_src_data_pack);
285
286void omap_set_dma_src_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
287{
288	unsigned int burst = 0;
289	u32 l;
290
291	l = p->dma_read(CSDP, lch);
292	l &= ~(0x03 << 7);
293
294	switch (burst_mode) {
295	case OMAP_DMA_DATA_BURST_DIS:
296		break;
297	case OMAP_DMA_DATA_BURST_4:
298		if (dma_omap2plus())
299			burst = 0x1;
300		else
301			burst = 0x2;
302		break;
303	case OMAP_DMA_DATA_BURST_8:
304		if (dma_omap2plus()) {
305			burst = 0x2;
306			break;
307		}
308		/*
309		 * not supported by current hardware on OMAP1
310		 * w |= (0x03 << 7);
311		 */
312		fallthrough;
313	case OMAP_DMA_DATA_BURST_16:
314		if (dma_omap2plus()) {
315			burst = 0x3;
316			break;
317		}
318		/* OMAP1 don't support burst 16 */
319		fallthrough;
320	default:
321		BUG();
322	}
323
324	l |= (burst << 7);
325	p->dma_write(l, CSDP, lch);
326}
327EXPORT_SYMBOL(omap_set_dma_src_burst_mode);
328
329/* Note that dest_port is only for OMAP1 */
330void omap_set_dma_dest_params(int lch, int dest_port, int dest_amode,
331			      unsigned long dest_start,
332			      int dst_ei, int dst_fi)
333{
334	u32 l;
335
336	if (dma_omap1()) {
337		l = p->dma_read(CSDP, lch);
338		l &= ~(0x1f << 9);
339		l |= dest_port << 9;
340		p->dma_write(l, CSDP, lch);
341	}
342
343	l = p->dma_read(CCR, lch);
344	l &= ~(0x03 << 14);
345	l |= dest_amode << 14;
346	p->dma_write(l, CCR, lch);
347
348	p->dma_write(dest_start, CDSA, lch);
349
350	p->dma_write(dst_ei, CDEI, lch);
351	p->dma_write(dst_fi, CDFI, lch);
352}
353EXPORT_SYMBOL(omap_set_dma_dest_params);
354
355void omap_set_dma_dest_data_pack(int lch, int enable)
356{
357	u32 l;
358
359	l = p->dma_read(CSDP, lch);
360	l &= ~(1 << 13);
361	if (enable)
362		l |= 1 << 13;
363	p->dma_write(l, CSDP, lch);
364}
365EXPORT_SYMBOL(omap_set_dma_dest_data_pack);
366
367void omap_set_dma_dest_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
368{
369	unsigned int burst = 0;
370	u32 l;
371
372	l = p->dma_read(CSDP, lch);
373	l &= ~(0x03 << 14);
374
375	switch (burst_mode) {
376	case OMAP_DMA_DATA_BURST_DIS:
377		break;
378	case OMAP_DMA_DATA_BURST_4:
379		if (dma_omap2plus())
380			burst = 0x1;
381		else
382			burst = 0x2;
383		break;
384	case OMAP_DMA_DATA_BURST_8:
385		if (dma_omap2plus())
386			burst = 0x2;
387		else
388			burst = 0x3;
389		break;
390	case OMAP_DMA_DATA_BURST_16:
391		if (dma_omap2plus()) {
392			burst = 0x3;
393			break;
394		}
395		/* OMAP1 don't support burst 16 */
396		fallthrough;
397	default:
398		printk(KERN_ERR "Invalid DMA burst mode\n");
399		BUG();
400		return;
401	}
402	l |= (burst << 14);
403	p->dma_write(l, CSDP, lch);
404}
405EXPORT_SYMBOL(omap_set_dma_dest_burst_mode);
406
407static inline void omap_enable_channel_irq(int lch)
408{
409	/* Clear CSR */
410	if (dma_omap1())
411		p->dma_read(CSR, lch);
412	else
413		p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
414
415	/* Enable some nice interrupts. */
416	p->dma_write(dma_chan[lch].enabled_irqs, CICR, lch);
417}
418
419static inline void omap_disable_channel_irq(int lch)
420{
421	/* disable channel interrupts */
422	p->dma_write(0, CICR, lch);
423	/* Clear CSR */
424	if (dma_omap1())
425		p->dma_read(CSR, lch);
426	else
427		p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
428}
429
430void omap_disable_dma_irq(int lch, u16 bits)
431{
432	dma_chan[lch].enabled_irqs &= ~bits;
433}
434EXPORT_SYMBOL(omap_disable_dma_irq);
435
436static inline void enable_lnk(int lch)
437{
438	u32 l;
439
440	l = p->dma_read(CLNK_CTRL, lch);
441
442	if (dma_omap1())
443		l &= ~(1 << 14);
444
445	/* Set the ENABLE_LNK bits */
446	if (dma_chan[lch].next_lch != -1)
447		l = dma_chan[lch].next_lch | (1 << 15);
448
449	p->dma_write(l, CLNK_CTRL, lch);
450}
451
452static inline void disable_lnk(int lch)
453{
454	u32 l;
455
456	l = p->dma_read(CLNK_CTRL, lch);
457
458	/* Disable interrupts */
459	omap_disable_channel_irq(lch);
460
461	if (dma_omap1()) {
462		/* Set the STOP_LNK bit */
463		l |= 1 << 14;
464	}
465
466	if (dma_omap2plus()) {
467		/* Clear the ENABLE_LNK bit */
468		l &= ~(1 << 15);
469	}
470
471	p->dma_write(l, CLNK_CTRL, lch);
472	dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
473}
474
475int omap_request_dma(int dev_id, const char *dev_name,
476		     void (*callback)(int lch, u16 ch_status, void *data),
477		     void *data, int *dma_ch_out)
478{
479	int ch, free_ch = -1;
480	unsigned long flags;
481	struct omap_dma_lch *chan;
482
483	WARN(strcmp(dev_name, "DMA engine"), "Using deprecated platform DMA API - please update to DMA engine");
484
485	spin_lock_irqsave(&dma_chan_lock, flags);
486	for (ch = 0; ch < dma_chan_count; ch++) {
487		if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
488			free_ch = ch;
489			/* Exit after first free channel found */
490			break;
491		}
492	}
493	if (free_ch == -1) {
494		spin_unlock_irqrestore(&dma_chan_lock, flags);
495		return -EBUSY;
496	}
497	chan = dma_chan + free_ch;
498	chan->dev_id = dev_id;
499
500	if (p->clear_lch_regs)
501		p->clear_lch_regs(free_ch);
502
503	spin_unlock_irqrestore(&dma_chan_lock, flags);
504
505	chan->dev_name = dev_name;
506	chan->callback = callback;
507	chan->data = data;
508	chan->flags = 0;
509
510	chan->enabled_irqs = OMAP_DMA_DROP_IRQ | OMAP_DMA_BLOCK_IRQ;
511
512	if (dma_omap1())
513		chan->enabled_irqs |= OMAP1_DMA_TOUT_IRQ;
514
515	if (dma_omap16xx()) {
516		/* If the sync device is set, configure it dynamically. */
517		if (dev_id != 0) {
518			set_gdma_dev(free_ch + 1, dev_id);
519			dev_id = free_ch + 1;
520		}
521		/*
522		 * Disable the 1510 compatibility mode and set the sync device
523		 * id.
524		 */
525		p->dma_write(dev_id | (1 << 10), CCR, free_ch);
526	} else if (dma_omap1()) {
527		p->dma_write(dev_id, CCR, free_ch);
528	}
529
530	*dma_ch_out = free_ch;
531
532	return 0;
533}
534EXPORT_SYMBOL(omap_request_dma);
535
536void omap_free_dma(int lch)
537{
538	unsigned long flags;
539
540	if (dma_chan[lch].dev_id == -1) {
541		pr_err("omap_dma: trying to free unallocated DMA channel %d\n",
542		       lch);
543		return;
544	}
545
546	/* Disable all DMA interrupts for the channel. */
547	omap_disable_channel_irq(lch);
548
549	/* Make sure the DMA transfer is stopped. */
550	p->dma_write(0, CCR, lch);
551
552	spin_lock_irqsave(&dma_chan_lock, flags);
553	dma_chan[lch].dev_id = -1;
554	dma_chan[lch].next_lch = -1;
555	dma_chan[lch].callback = NULL;
556	spin_unlock_irqrestore(&dma_chan_lock, flags);
557}
558EXPORT_SYMBOL(omap_free_dma);
559
560/*
561 * Clears any DMA state so the DMA engine is ready to restart with new buffers
562 * through omap_start_dma(). Any buffers in flight are discarded.
563 */
564static void omap_clear_dma(int lch)
565{
566	unsigned long flags;
567
568	local_irq_save(flags);
569	p->clear_dma(lch);
570	local_irq_restore(flags);
571}
572
573void omap_start_dma(int lch)
574{
575	u32 l;
576
577	/*
578	 * The CPC/CDAC register needs to be initialized to zero
579	 * before starting dma transfer.
580	 */
581	if (dma_omap15xx())
582		p->dma_write(0, CPC, lch);
583	else
584		p->dma_write(0, CDAC, lch);
585
586	if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
587		int next_lch, cur_lch;
588		char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
589
590		/* Set the link register of the first channel */
591		enable_lnk(lch);
592
593		memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
594		dma_chan_link_map[lch] = 1;
595
596		cur_lch = dma_chan[lch].next_lch;
597		do {
598			next_lch = dma_chan[cur_lch].next_lch;
599
600			/* The loop case: we've been here already */
601			if (dma_chan_link_map[cur_lch])
602				break;
603			/* Mark the current channel */
604			dma_chan_link_map[cur_lch] = 1;
605
606			enable_lnk(cur_lch);
607			omap_enable_channel_irq(cur_lch);
608
609			cur_lch = next_lch;
610		} while (next_lch != -1);
611	} else if (IS_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS))
612		p->dma_write(lch, CLNK_CTRL, lch);
613
614	omap_enable_channel_irq(lch);
615
616	l = p->dma_read(CCR, lch);
617
618	if (IS_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING))
619			l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
620	l |= OMAP_DMA_CCR_EN;
621
622	/*
623	 * As dma_write() uses IO accessors which are weakly ordered, there
624	 * is no guarantee that data in coherent DMA memory will be visible
625	 * to the DMA device.  Add a memory barrier here to ensure that any
626	 * such data is visible prior to enabling DMA.
627	 */
628	mb();
629	p->dma_write(l, CCR, lch);
630
631	dma_chan[lch].flags |= OMAP_DMA_ACTIVE;
632}
633EXPORT_SYMBOL(omap_start_dma);
634
635void omap_stop_dma(int lch)
636{
637	u32 l;
638
639	/* Disable all interrupts on the channel */
640	omap_disable_channel_irq(lch);
641
642	l = p->dma_read(CCR, lch);
643	if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&
644			(l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
645		int i = 0;
646		u32 sys_cf;
647
648		/* Configure No-Standby */
649		l = p->dma_read(OCP_SYSCONFIG, lch);
650		sys_cf = l;
651		l &= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
652		l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
653		p->dma_write(l , OCP_SYSCONFIG, 0);
654
655		l = p->dma_read(CCR, lch);
656		l &= ~OMAP_DMA_CCR_EN;
657		p->dma_write(l, CCR, lch);
658
659		/* Wait for sDMA FIFO drain */
660		l = p->dma_read(CCR, lch);
661		while (i < 100 && (l & (OMAP_DMA_CCR_RD_ACTIVE |
662					OMAP_DMA_CCR_WR_ACTIVE))) {
663			udelay(5);
664			i++;
665			l = p->dma_read(CCR, lch);
666		}
667		if (i >= 100)
668			pr_err("DMA drain did not complete on lch %d\n", lch);
669		/* Restore OCP_SYSCONFIG */
670		p->dma_write(sys_cf, OCP_SYSCONFIG, lch);
671	} else {
672		l &= ~OMAP_DMA_CCR_EN;
673		p->dma_write(l, CCR, lch);
674	}
675
676	/*
677	 * Ensure that data transferred by DMA is visible to any access
678	 * after DMA has been disabled.  This is important for coherent
679	 * DMA regions.
680	 */
681	mb();
682
683	if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
684		int next_lch, cur_lch = lch;
685		char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
686
687		memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
688		do {
689			/* The loop case: we've been here already */
690			if (dma_chan_link_map[cur_lch])
691				break;
692			/* Mark the current channel */
693			dma_chan_link_map[cur_lch] = 1;
694
695			disable_lnk(cur_lch);
696
697			next_lch = dma_chan[cur_lch].next_lch;
698			cur_lch = next_lch;
699		} while (next_lch != -1);
700	}
701
702	dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
703}
704EXPORT_SYMBOL(omap_stop_dma);
705
706/*
707 * Allows changing the DMA callback function or data. This may be needed if
708 * the driver shares a single DMA channel for multiple dma triggers.
709 */
710/*
711 * Returns current physical source address for the given DMA channel.
712 * If the channel is running the caller must disable interrupts prior calling
713 * this function and process the returned value before re-enabling interrupt to
714 * prevent races with the interrupt handler. Note that in continuous mode there
715 * is a chance for CSSA_L register overflow between the two reads resulting
716 * in incorrect return value.
717 */
718dma_addr_t omap_get_dma_src_pos(int lch)
719{
720	dma_addr_t offset = 0;
721
722	if (dma_omap15xx())
723		offset = p->dma_read(CPC, lch);
724	else
725		offset = p->dma_read(CSAC, lch);
726
727	if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0)
728		offset = p->dma_read(CSAC, lch);
729
730	if (!dma_omap15xx()) {
731		/*
732		 * CDAC == 0 indicates that the DMA transfer on the channel has
733		 * not been started (no data has been transferred so far).
734		 * Return the programmed source start address in this case.
735		 */
736		if (likely(p->dma_read(CDAC, lch)))
737			offset = p->dma_read(CSAC, lch);
738		else
739			offset = p->dma_read(CSSA, lch);
740	}
741
742	if (dma_omap1())
743		offset |= (p->dma_read(CSSA, lch) & 0xFFFF0000);
744
745	return offset;
746}
747EXPORT_SYMBOL(omap_get_dma_src_pos);
748
749/*
750 * Returns current physical destination address for the given DMA channel.
751 * If the channel is running the caller must disable interrupts prior calling
752 * this function and process the returned value before re-enabling interrupt to
753 * prevent races with the interrupt handler. Note that in continuous mode there
754 * is a chance for CDSA_L register overflow between the two reads resulting
755 * in incorrect return value.
756 */
757dma_addr_t omap_get_dma_dst_pos(int lch)
758{
759	dma_addr_t offset = 0;
760
761	if (dma_omap15xx())
762		offset = p->dma_read(CPC, lch);
763	else
764		offset = p->dma_read(CDAC, lch);
765
766	/*
767	 * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
768	 * read before the DMA controller finished disabling the channel.
769	 */
770	if (!dma_omap15xx() && offset == 0) {
771		offset = p->dma_read(CDAC, lch);
772		/*
773		 * CDAC == 0 indicates that the DMA transfer on the channel has
774		 * not been started (no data has been transferred so far).
775		 * Return the programmed destination start address in this case.
776		 */
777		if (unlikely(!offset))
778			offset = p->dma_read(CDSA, lch);
779	}
780
781	if (dma_omap1())
782		offset |= (p->dma_read(CDSA, lch) & 0xFFFF0000);
783
784	return offset;
785}
786EXPORT_SYMBOL(omap_get_dma_dst_pos);
787
788int omap_get_dma_active_status(int lch)
789{
790	return (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN) != 0;
791}
792EXPORT_SYMBOL(omap_get_dma_active_status);
793
794int omap_dma_running(void)
795{
796	int lch;
797
798	if (dma_omap1())
799		if (omap_lcd_dma_running())
800			return 1;
801
802	for (lch = 0; lch < dma_chan_count; lch++)
803		if (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN)
804			return 1;
805
806	return 0;
807}
808
809/*----------------------------------------------------------------------------*/
810
811#ifdef CONFIG_ARCH_OMAP1
812
813static int omap1_dma_handle_ch(int ch)
814{
815	u32 csr;
816
817	if (enable_1510_mode && ch >= 6) {
818		csr = dma_chan[ch].saved_csr;
819		dma_chan[ch].saved_csr = 0;
820	} else
821		csr = p->dma_read(CSR, ch);
822	if (enable_1510_mode && ch <= 2 && (csr >> 7) != 0) {
823		dma_chan[ch + 6].saved_csr = csr >> 7;
824		csr &= 0x7f;
825	}
826	if ((csr & 0x3f) == 0)
827		return 0;
828	if (unlikely(dma_chan[ch].dev_id == -1)) {
829		pr_warn("Spurious interrupt from DMA channel %d (CSR %04x)\n",
830			ch, csr);
831		return 0;
832	}
833	if (unlikely(csr & OMAP1_DMA_TOUT_IRQ))
834		pr_warn("DMA timeout with device %d\n", dma_chan[ch].dev_id);
835	if (unlikely(csr & OMAP_DMA_DROP_IRQ))
836		pr_warn("DMA synchronization event drop occurred with device %d\n",
837			dma_chan[ch].dev_id);
838	if (likely(csr & OMAP_DMA_BLOCK_IRQ))
839		dma_chan[ch].flags &= ~OMAP_DMA_ACTIVE;
840	if (likely(dma_chan[ch].callback != NULL))
841		dma_chan[ch].callback(ch, csr, dma_chan[ch].data);
842
843	return 1;
844}
845
846static irqreturn_t omap1_dma_irq_handler(int irq, void *dev_id)
847{
848	int ch = ((int) dev_id) - 1;
849	int handled = 0;
850
851	for (;;) {
852		int handled_now = 0;
853
854		handled_now += omap1_dma_handle_ch(ch);
855		if (enable_1510_mode && dma_chan[ch + 6].saved_csr)
856			handled_now += omap1_dma_handle_ch(ch + 6);
857		if (!handled_now)
858			break;
859		handled += handled_now;
860	}
861
862	return handled ? IRQ_HANDLED : IRQ_NONE;
863}
864
865#else
866#define omap1_dma_irq_handler	NULL
867#endif
868
869struct omap_system_dma_plat_info *omap_get_plat_info(void)
870{
871	return p;
872}
873EXPORT_SYMBOL_GPL(omap_get_plat_info);
874
875static int omap_system_dma_probe(struct platform_device *pdev)
876{
877	int ch, ret = 0;
878	int dma_irq;
879	char irq_name[4];
880
881	p = pdev->dev.platform_data;
882	if (!p) {
883		dev_err(&pdev->dev,
884			"%s: System DMA initialized without platform data\n",
885			__func__);
886		return -EINVAL;
887	}
888
889	d			= p->dma_attr;
890	errata			= p->errata;
891
892	if ((d->dev_caps & RESERVE_CHANNEL) && omap_dma_reserve_channels
893			&& (omap_dma_reserve_channels < d->lch_count))
894		d->lch_count	= omap_dma_reserve_channels;
895
896	dma_lch_count		= d->lch_count;
897	dma_chan_count		= dma_lch_count;
898	enable_1510_mode	= d->dev_caps & ENABLE_1510_MODE;
899
900	dma_chan = devm_kcalloc(&pdev->dev, dma_lch_count,
901				sizeof(*dma_chan), GFP_KERNEL);
902	if (!dma_chan)
903		return -ENOMEM;
904
905	spin_lock_init(&dma_chan_lock);
906	for (ch = 0; ch < dma_chan_count; ch++) {
907		omap_clear_dma(ch);
908
909		dma_chan[ch].dev_id = -1;
910		dma_chan[ch].next_lch = -1;
911
912		if (ch >= 6 && enable_1510_mode)
913			continue;
914
915		if (dma_omap1()) {
916			/*
917			 * request_irq() doesn't like dev_id (ie. ch) being
918			 * zero, so we have to kludge around this.
919			 */
920			sprintf(&irq_name[0], "%d", ch);
921			dma_irq = platform_get_irq_byname(pdev, irq_name);
922
923			if (dma_irq < 0) {
924				ret = dma_irq;
925				goto exit_dma_irq_fail;
926			}
927
928			/* INT_DMA_LCD is handled in lcd_dma.c */
929			if (dma_irq == INT_DMA_LCD)
930				continue;
931
932			ret = request_irq(dma_irq,
933					omap1_dma_irq_handler, 0, "DMA",
934					(void *) (ch + 1));
935			if (ret != 0)
936				goto exit_dma_irq_fail;
937		}
938	}
939
940	/* reserve dma channels 0 and 1 in high security devices on 34xx */
941	if (d->dev_caps & HS_CHANNELS_RESERVED) {
942		pr_info("Reserving DMA channels 0 and 1 for HS ROM code\n");
943		dma_chan[0].dev_id = 0;
944		dma_chan[1].dev_id = 1;
945	}
946	p->show_dma_caps();
947	return 0;
948
949exit_dma_irq_fail:
950	return ret;
951}
952
953static int omap_system_dma_remove(struct platform_device *pdev)
954{
955	int dma_irq, irq_rel = 0;
956
957	if (dma_omap2plus())
958		return 0;
959
960	for ( ; irq_rel < dma_chan_count; irq_rel++) {
961		dma_irq = platform_get_irq(pdev, irq_rel);
962		free_irq(dma_irq, (void *)(irq_rel + 1));
963	}
964
965	return 0;
966}
967
968static struct platform_driver omap_system_dma_driver = {
969	.probe		= omap_system_dma_probe,
970	.remove		= omap_system_dma_remove,
971	.driver		= {
972		.name	= "omap_dma_system"
973	},
974};
975
976static int __init omap_system_dma_init(void)
977{
978	return platform_driver_register(&omap_system_dma_driver);
979}
980arch_initcall(omap_system_dma_init);
981
982static void __exit omap_system_dma_exit(void)
983{
984	platform_driver_unregister(&omap_system_dma_driver);
985}
986
987MODULE_DESCRIPTION("OMAP SYSTEM DMA DRIVER");
988MODULE_LICENSE("GPL");
989MODULE_AUTHOR("Texas Instruments Inc");
990
991/*
992 * Reserve the omap SDMA channels using cmdline bootarg
993 * "omap_dma_reserve_ch=". The valid range is 1 to 32
994 */
995static int __init omap_dma_cmdline_reserve_ch(char *str)
996{
997	if (get_option(&str, &omap_dma_reserve_channels) != 1)
998		omap_dma_reserve_channels = 0;
999	return 1;
1000}
1001
1002__setup("omap_dma_reserve_ch=", omap_dma_cmdline_reserve_ch);
1003
1004
1005