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TOMOYO Linux Cross Reference
Linux/arch/arm/mach-omap1/omap-dma.c

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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 
 57 static struct omap_system_dma_plat_info *p;
 58 static struct omap_dma_dev_attr *d;
 59 static int enable_1510_mode;
 60 static u32 errata;
 61 
 62 struct 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 
 75 static int dma_lch_count;
 76 static int dma_chan_count;
 77 static int omap_dma_reserve_channels;
 78 
 79 static DEFINE_SPINLOCK(dma_chan_lock);
 80 static struct omap_dma_lch *dma_chan;
 81 
 82 static 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 
 90 static 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)
103 void 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 }
132 EXPORT_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 */
138 static 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 
146 void 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 }
172 EXPORT_SYMBOL(omap_set_dma_transfer_params);
173 
174 void 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 }
185 EXPORT_SYMBOL(omap_set_dma_channel_mode);
186 
187 /* Note that src_port is only for omap1 */
188 void 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 }
210 EXPORT_SYMBOL(omap_set_dma_src_params);
211 
212 void 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 }
222 EXPORT_SYMBOL(omap_set_dma_src_data_pack);
223 
224 void 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 }
254 EXPORT_SYMBOL(omap_set_dma_src_burst_mode);
255 
256 /* Note that dest_port is only for OMAP1 */
257 void 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 }
278 EXPORT_SYMBOL(omap_set_dma_dest_params);
279 
280 void 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 }
290 EXPORT_SYMBOL(omap_set_dma_dest_data_pack);
291 
292 void 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 }
320 EXPORT_SYMBOL(omap_set_dma_dest_burst_mode);
321 
322 static 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 
331 void omap_disable_dma_irq(int lch, u16 bits)
332 {
333         dma_chan[lch].enabled_irqs &= ~bits;
334 }
335 EXPORT_SYMBOL(omap_disable_dma_irq);
336 
337 static 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 
352 static 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 
369 int 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 }
427 EXPORT_SYMBOL(omap_request_dma);
428 
429 void 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 }
451 EXPORT_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  */
457 static 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)
467 void 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 }
527 EXPORT_SYMBOL(omap_start_dma);
528 
529 void 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 }
598 EXPORT_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  */
612 dma_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 }
640 EXPORT_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  */
650 dma_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 }
678 EXPORT_SYMBOL(omap_get_dma_dst_pos);
679 
680 int omap_get_dma_active_status(int lch)
681 {
682         return (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN) != 0;
683 }
684 EXPORT_SYMBOL(omap_get_dma_active_status);
685 #endif
686 
687 int 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 
703 static 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 
736 static 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 
755 struct omap_system_dma_plat_info *omap_get_plat_info(void)
756 {
757         return p;
758 }
759 EXPORT_SYMBOL_GPL(omap_get_plat_info);
760 
761 static 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 
832 exit_dma_irq_fail:
833         return ret;
834 }
835 
836 static 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 
846 static 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 
854 static int __init omap_system_dma_init(void)
855 {
856         return platform_driver_register(&omap_system_dma_driver);
857 }
858 arch_initcall(omap_system_dma_init);
859 
860 static void __exit omap_system_dma_exit(void)
861 {
862         platform_driver_unregister(&omap_system_dma_driver);
863 }
864 
865 MODULE_DESCRIPTION("OMAP SYSTEM DMA DRIVER");
866 MODULE_LICENSE("GPL");
867 MODULE_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  */
873 static 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 
883 

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