xref: /openbmc/qemu/hw/dma/etraxfs_dma.c (revision ddbb0d09)
1 /*
2  * QEMU ETRAX DMA Controller.
3  *
4  * Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include <stdio.h>
25 #include <sys/time.h>
26 #include "hw/hw.h"
27 #include "exec/address-spaces.h"
28 #include "qemu-common.h"
29 #include "sysemu/sysemu.h"
30 
31 #include "hw/cris/etraxfs_dma.h"
32 
33 #define D(x)
34 
35 #define RW_DATA           (0x0 / 4)
36 #define RW_SAVED_DATA     (0x58 / 4)
37 #define RW_SAVED_DATA_BUF (0x5c / 4)
38 #define RW_GROUP          (0x60 / 4)
39 #define RW_GROUP_DOWN     (0x7c / 4)
40 #define RW_CMD            (0x80 / 4)
41 #define RW_CFG            (0x84 / 4)
42 #define RW_STAT           (0x88 / 4)
43 #define RW_INTR_MASK      (0x8c / 4)
44 #define RW_ACK_INTR       (0x90 / 4)
45 #define R_INTR            (0x94 / 4)
46 #define R_MASKED_INTR     (0x98 / 4)
47 #define RW_STREAM_CMD     (0x9c / 4)
48 
49 #define DMA_REG_MAX       (0x100 / 4)
50 
51 /* descriptors */
52 
53 // ------------------------------------------------------------ dma_descr_group
54 typedef struct dma_descr_group {
55   uint32_t                      next;
56   unsigned                      eol        : 1;
57   unsigned                      tol        : 1;
58   unsigned                      bol        : 1;
59   unsigned                                 : 1;
60   unsigned                      intr       : 1;
61   unsigned                                 : 2;
62   unsigned                      en         : 1;
63   unsigned                                 : 7;
64   unsigned                      dis        : 1;
65   unsigned                      md         : 16;
66   struct dma_descr_group       *up;
67   union {
68     struct dma_descr_context   *context;
69     struct dma_descr_group     *group;
70   }                             down;
71 } dma_descr_group;
72 
73 // ---------------------------------------------------------- dma_descr_context
74 typedef struct dma_descr_context {
75   uint32_t                      next;
76   unsigned                      eol        : 1;
77   unsigned                                 : 3;
78   unsigned                      intr       : 1;
79   unsigned                                 : 1;
80   unsigned                      store_mode : 1;
81   unsigned                      en         : 1;
82   unsigned                                 : 7;
83   unsigned                      dis        : 1;
84   unsigned                      md0        : 16;
85   unsigned                      md1;
86   unsigned                      md2;
87   unsigned                      md3;
88   unsigned                      md4;
89   uint32_t                      saved_data;
90   uint32_t                      saved_data_buf;
91 } dma_descr_context;
92 
93 // ------------------------------------------------------------- dma_descr_data
94 typedef struct dma_descr_data {
95   uint32_t                      next;
96   uint32_t                      buf;
97   unsigned                      eol        : 1;
98   unsigned                                 : 2;
99   unsigned                      out_eop    : 1;
100   unsigned                      intr       : 1;
101   unsigned                      wait       : 1;
102   unsigned                                 : 2;
103   unsigned                                 : 3;
104   unsigned                      in_eop     : 1;
105   unsigned                                 : 4;
106   unsigned                      md         : 16;
107   uint32_t                      after;
108 } dma_descr_data;
109 
110 /* Constants */
111 enum {
112   regk_dma_ack_pkt                         = 0x00000100,
113   regk_dma_anytime                         = 0x00000001,
114   regk_dma_array                           = 0x00000008,
115   regk_dma_burst                           = 0x00000020,
116   regk_dma_client                          = 0x00000002,
117   regk_dma_copy_next                       = 0x00000010,
118   regk_dma_copy_up                         = 0x00000020,
119   regk_dma_data_at_eol                     = 0x00000001,
120   regk_dma_dis_c                           = 0x00000010,
121   regk_dma_dis_g                           = 0x00000020,
122   regk_dma_idle                            = 0x00000001,
123   regk_dma_intern                          = 0x00000004,
124   regk_dma_load_c                          = 0x00000200,
125   regk_dma_load_c_n                        = 0x00000280,
126   regk_dma_load_c_next                     = 0x00000240,
127   regk_dma_load_d                          = 0x00000140,
128   regk_dma_load_g                          = 0x00000300,
129   regk_dma_load_g_down                     = 0x000003c0,
130   regk_dma_load_g_next                     = 0x00000340,
131   regk_dma_load_g_up                       = 0x00000380,
132   regk_dma_next_en                         = 0x00000010,
133   regk_dma_next_pkt                        = 0x00000010,
134   regk_dma_no                              = 0x00000000,
135   regk_dma_only_at_wait                    = 0x00000000,
136   regk_dma_restore                         = 0x00000020,
137   regk_dma_rst                             = 0x00000001,
138   regk_dma_running                         = 0x00000004,
139   regk_dma_rw_cfg_default                  = 0x00000000,
140   regk_dma_rw_cmd_default                  = 0x00000000,
141   regk_dma_rw_intr_mask_default            = 0x00000000,
142   regk_dma_rw_stat_default                 = 0x00000101,
143   regk_dma_rw_stream_cmd_default           = 0x00000000,
144   regk_dma_save_down                       = 0x00000020,
145   regk_dma_save_up                         = 0x00000020,
146   regk_dma_set_reg                         = 0x00000050,
147   regk_dma_set_w_size1                     = 0x00000190,
148   regk_dma_set_w_size2                     = 0x000001a0,
149   regk_dma_set_w_size4                     = 0x000001c0,
150   regk_dma_stopped                         = 0x00000002,
151   regk_dma_store_c                         = 0x00000002,
152   regk_dma_store_descr                     = 0x00000000,
153   regk_dma_store_g                         = 0x00000004,
154   regk_dma_store_md                        = 0x00000001,
155   regk_dma_sw                              = 0x00000008,
156   regk_dma_update_down                     = 0x00000020,
157   regk_dma_yes                             = 0x00000001
158 };
159 
160 enum dma_ch_state
161 {
162 	RST = 1,
163 	STOPPED = 2,
164 	RUNNING = 4
165 };
166 
167 struct fs_dma_channel
168 {
169 	qemu_irq irq;
170 	struct etraxfs_dma_client *client;
171 
172 	/* Internal status.  */
173 	int stream_cmd_src;
174 	enum dma_ch_state state;
175 
176 	unsigned int input : 1;
177 	unsigned int eol : 1;
178 
179 	struct dma_descr_group current_g;
180 	struct dma_descr_context current_c;
181 	struct dma_descr_data current_d;
182 
183 	/* Control registers.  */
184 	uint32_t regs[DMA_REG_MAX];
185 };
186 
187 struct fs_dma_ctrl
188 {
189 	MemoryRegion mmio;
190 	int nr_channels;
191 	struct fs_dma_channel *channels;
192 
193         QEMUBH *bh;
194 };
195 
196 static void DMA_run(void *opaque);
197 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
198 
199 static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
200 {
201 	return ctrl->channels[c].regs[reg];
202 }
203 
204 static inline int channel_stopped(struct fs_dma_ctrl *ctrl, int c)
205 {
206 	return channel_reg(ctrl, c, RW_CFG) & 2;
207 }
208 
209 static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
210 {
211 	return (channel_reg(ctrl, c, RW_CFG) & 1)
212 		&& ctrl->channels[c].client;
213 }
214 
215 static inline int fs_channel(hwaddr addr)
216 {
217 	/* Every channel has a 0x2000 ctrl register map.  */
218 	return addr >> 13;
219 }
220 
221 #ifdef USE_THIS_DEAD_CODE
222 static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
223 {
224 	hwaddr addr = channel_reg(ctrl, c, RW_GROUP);
225 
226 	/* Load and decode. FIXME: handle endianness.  */
227 	cpu_physical_memory_read (addr,
228 				  (void *) &ctrl->channels[c].current_g,
229 				  sizeof ctrl->channels[c].current_g);
230 }
231 
232 static void dump_c(int ch, struct dma_descr_context *c)
233 {
234 	printf("%s ch=%d\n", __func__, ch);
235 	printf("next=%x\n", c->next);
236 	printf("saved_data=%x\n", c->saved_data);
237 	printf("saved_data_buf=%x\n", c->saved_data_buf);
238 	printf("eol=%x\n", (uint32_t) c->eol);
239 }
240 
241 static void dump_d(int ch, struct dma_descr_data *d)
242 {
243 	printf("%s ch=%d\n", __func__, ch);
244 	printf("next=%x\n", d->next);
245 	printf("buf=%x\n", d->buf);
246 	printf("after=%x\n", d->after);
247 	printf("intr=%x\n", (uint32_t) d->intr);
248 	printf("out_eop=%x\n", (uint32_t) d->out_eop);
249 	printf("in_eop=%x\n", (uint32_t) d->in_eop);
250 	printf("eol=%x\n", (uint32_t) d->eol);
251 }
252 #endif
253 
254 static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
255 {
256 	hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
257 
258 	/* Load and decode. FIXME: handle endianness.  */
259 	cpu_physical_memory_read (addr,
260 				  (void *) &ctrl->channels[c].current_c,
261 				  sizeof ctrl->channels[c].current_c);
262 
263 	D(dump_c(c, &ctrl->channels[c].current_c));
264 	/* I guess this should update the current pos.  */
265 	ctrl->channels[c].regs[RW_SAVED_DATA] =
266 		(uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data;
267 	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
268 		(uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data_buf;
269 }
270 
271 static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
272 {
273 	hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
274 
275 	/* Load and decode. FIXME: handle endianness.  */
276 	D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
277 	cpu_physical_memory_read (addr,
278 				  (void *) &ctrl->channels[c].current_d,
279 				  sizeof ctrl->channels[c].current_d);
280 
281 	D(dump_d(c, &ctrl->channels[c].current_d));
282 	ctrl->channels[c].regs[RW_DATA] = addr;
283 }
284 
285 static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
286 {
287 	hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
288 
289 	/* Encode and store. FIXME: handle endianness.  */
290 	D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
291 	D(dump_d(c, &ctrl->channels[c].current_d));
292 	cpu_physical_memory_write (addr,
293 				  (void *) &ctrl->channels[c].current_c,
294 				  sizeof ctrl->channels[c].current_c);
295 }
296 
297 static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
298 {
299 	hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
300 
301 	/* Encode and store. FIXME: handle endianness.  */
302 	D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
303 	cpu_physical_memory_write (addr,
304 				  (void *) &ctrl->channels[c].current_d,
305 				  sizeof ctrl->channels[c].current_d);
306 }
307 
308 static inline void channel_stop(struct fs_dma_ctrl *ctrl, int c)
309 {
310 	/* FIXME:  */
311 }
312 
313 static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
314 {
315 	if (ctrl->channels[c].client)
316 	{
317 		ctrl->channels[c].eol = 0;
318 		ctrl->channels[c].state = RUNNING;
319 		if (!ctrl->channels[c].input)
320 			channel_out_run(ctrl, c);
321 	} else
322 		printf("WARNING: starting DMA ch %d with no client\n", c);
323 
324         qemu_bh_schedule_idle(ctrl->bh);
325 }
326 
327 static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
328 {
329 	if (!channel_en(ctrl, c)
330 	    || channel_stopped(ctrl, c)
331 	    || ctrl->channels[c].state != RUNNING
332 	    /* Only reload the current data descriptor if it has eol set.  */
333 	    || !ctrl->channels[c].current_d.eol) {
334 		D(printf("continue failed ch=%d state=%d stopped=%d en=%d eol=%d\n",
335 			 c, ctrl->channels[c].state,
336 			 channel_stopped(ctrl, c),
337 			 channel_en(ctrl,c),
338 			 ctrl->channels[c].eol));
339 		D(dump_d(c, &ctrl->channels[c].current_d));
340 		return;
341 	}
342 
343 	/* Reload the current descriptor.  */
344 	channel_load_d(ctrl, c);
345 
346 	/* If the current descriptor cleared the eol flag and we had already
347 	   reached eol state, do the continue.  */
348 	if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
349 		D(printf("continue %d ok %x\n", c,
350 			 ctrl->channels[c].current_d.next));
351 		ctrl->channels[c].regs[RW_SAVED_DATA] =
352 			(uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
353 		channel_load_d(ctrl, c);
354 		ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
355 			(uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
356 
357 		channel_start(ctrl, c);
358 	}
359 	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
360 		(uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
361 }
362 
363 static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
364 {
365 	unsigned int cmd = v & ((1 << 10) - 1);
366 
367 	D(printf("%s ch=%d cmd=%x\n",
368 		 __func__, c, cmd));
369 	if (cmd & regk_dma_load_d) {
370 		channel_load_d(ctrl, c);
371 		if (cmd & regk_dma_burst)
372 			channel_start(ctrl, c);
373 	}
374 
375 	if (cmd & regk_dma_load_c) {
376 		channel_load_c(ctrl, c);
377 	}
378 }
379 
380 static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
381 {
382 	D(printf("%s %d\n", __func__, c));
383         ctrl->channels[c].regs[R_INTR] &=
384 		~(ctrl->channels[c].regs[RW_ACK_INTR]);
385 
386         ctrl->channels[c].regs[R_MASKED_INTR] =
387 		ctrl->channels[c].regs[R_INTR]
388 		& ctrl->channels[c].regs[RW_INTR_MASK];
389 
390 	D(printf("%s: chan=%d masked_intr=%x\n", __func__,
391 		 c,
392 		 ctrl->channels[c].regs[R_MASKED_INTR]));
393 
394         qemu_set_irq(ctrl->channels[c].irq,
395 		     !!ctrl->channels[c].regs[R_MASKED_INTR]);
396 }
397 
398 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
399 {
400 	uint32_t len;
401 	uint32_t saved_data_buf;
402 	unsigned char buf[2 * 1024];
403 
404 	struct dma_context_metadata meta;
405 	bool send_context = true;
406 
407 	if (ctrl->channels[c].eol)
408 		return 0;
409 
410 	do {
411 		bool out_eop;
412 		D(printf("ch=%d buf=%x after=%x\n",
413 			 c,
414 			 (uint32_t)ctrl->channels[c].current_d.buf,
415 			 (uint32_t)ctrl->channels[c].current_d.after));
416 
417 		if (send_context) {
418 			if (ctrl->channels[c].client->client.metadata_push) {
419 				meta.metadata = ctrl->channels[c].current_d.md;
420 				ctrl->channels[c].client->client.metadata_push(
421 					ctrl->channels[c].client->client.opaque,
422 					&meta);
423 			}
424 			send_context = false;
425 		}
426 
427 		channel_load_d(ctrl, c);
428 		saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
429 		len = (uint32_t)(unsigned long)
430 			ctrl->channels[c].current_d.after;
431 		len -= saved_data_buf;
432 
433 		if (len > sizeof buf)
434 			len = sizeof buf;
435 		cpu_physical_memory_read (saved_data_buf, buf, len);
436 
437 		out_eop = ((saved_data_buf + len) ==
438 		           ctrl->channels[c].current_d.after) &&
439 			ctrl->channels[c].current_d.out_eop;
440 
441 		D(printf("channel %d pushes %x %u bytes eop=%u\n", c,
442 		         saved_data_buf, len, out_eop));
443 
444 		if (ctrl->channels[c].client->client.push)
445 			ctrl->channels[c].client->client.push(
446 				ctrl->channels[c].client->client.opaque,
447 				buf, len, out_eop);
448 		else
449 			printf("WARNING: DMA ch%d dataloss,"
450 			       " no attached client.\n", c);
451 
452 		saved_data_buf += len;
453 
454 		if (saved_data_buf == (uint32_t)(unsigned long)
455 				ctrl->channels[c].current_d.after) {
456 			/* Done. Step to next.  */
457 			if (ctrl->channels[c].current_d.out_eop) {
458 				send_context = true;
459 			}
460 			if (ctrl->channels[c].current_d.intr) {
461 				/* data intr.  */
462 				D(printf("signal intr %d eol=%d\n",
463 					len, ctrl->channels[c].current_d.eol));
464 				ctrl->channels[c].regs[R_INTR] |= (1 << 2);
465 				channel_update_irq(ctrl, c);
466 			}
467 			channel_store_d(ctrl, c);
468 			if (ctrl->channels[c].current_d.eol) {
469 				D(printf("channel %d EOL\n", c));
470 				ctrl->channels[c].eol = 1;
471 
472 				/* Mark the context as disabled.  */
473 				ctrl->channels[c].current_c.dis = 1;
474 				channel_store_c(ctrl, c);
475 
476 				channel_stop(ctrl, c);
477 			} else {
478 				ctrl->channels[c].regs[RW_SAVED_DATA] =
479 					(uint32_t)(unsigned long)ctrl->
480 						channels[c].current_d.next;
481 				/* Load new descriptor.  */
482 				channel_load_d(ctrl, c);
483 				saved_data_buf = (uint32_t)(unsigned long)
484 					ctrl->channels[c].current_d.buf;
485 			}
486 
487 			ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
488 							saved_data_buf;
489 			D(dump_d(c, &ctrl->channels[c].current_d));
490 		}
491 		ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
492 	} while (!ctrl->channels[c].eol);
493 	return 1;
494 }
495 
496 static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
497 			      unsigned char *buf, int buflen, int eop)
498 {
499 	uint32_t len;
500 	uint32_t saved_data_buf;
501 
502 	if (ctrl->channels[c].eol == 1)
503 		return 0;
504 
505 	channel_load_d(ctrl, c);
506 	saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
507 	len = (uint32_t)(unsigned long)ctrl->channels[c].current_d.after;
508 	len -= saved_data_buf;
509 
510 	if (len > buflen)
511 		len = buflen;
512 
513 	cpu_physical_memory_write (saved_data_buf, buf, len);
514 	saved_data_buf += len;
515 
516 	if (saved_data_buf ==
517 	    (uint32_t)(unsigned long)ctrl->channels[c].current_d.after
518 	    || eop) {
519 		uint32_t r_intr = ctrl->channels[c].regs[R_INTR];
520 
521 		D(printf("in dscr end len=%d\n",
522 			 ctrl->channels[c].current_d.after
523 			 - ctrl->channels[c].current_d.buf));
524 		ctrl->channels[c].current_d.after = saved_data_buf;
525 
526 		/* Done. Step to next.  */
527 		if (ctrl->channels[c].current_d.intr) {
528 			/* TODO: signal eop to the client.  */
529 			/* data intr.  */
530 			ctrl->channels[c].regs[R_INTR] |= 3;
531 		}
532 		if (eop) {
533 			ctrl->channels[c].current_d.in_eop = 1;
534 			ctrl->channels[c].regs[R_INTR] |= 8;
535 		}
536 		if (r_intr != ctrl->channels[c].regs[R_INTR])
537 			channel_update_irq(ctrl, c);
538 
539 		channel_store_d(ctrl, c);
540 		D(dump_d(c, &ctrl->channels[c].current_d));
541 
542 		if (ctrl->channels[c].current_d.eol) {
543 			D(printf("channel %d EOL\n", c));
544 			ctrl->channels[c].eol = 1;
545 
546 			/* Mark the context as disabled.  */
547 			ctrl->channels[c].current_c.dis = 1;
548 			channel_store_c(ctrl, c);
549 
550 			channel_stop(ctrl, c);
551 		} else {
552 			ctrl->channels[c].regs[RW_SAVED_DATA] =
553 				(uint32_t)(unsigned long)ctrl->
554 					channels[c].current_d.next;
555 			/* Load new descriptor.  */
556 			channel_load_d(ctrl, c);
557 			saved_data_buf = (uint32_t)(unsigned long)
558 				ctrl->channels[c].current_d.buf;
559 		}
560 	}
561 
562 	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
563 	return len;
564 }
565 
566 static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
567 {
568 	if (ctrl->channels[c].client->client.pull) {
569 		ctrl->channels[c].client->client.pull(
570 			ctrl->channels[c].client->client.opaque);
571 		return 1;
572 	} else
573 		return 0;
574 }
575 
576 static uint32_t dma_rinvalid (void *opaque, hwaddr addr)
577 {
578         hw_error("Unsupported short raccess. reg=" TARGET_FMT_plx "\n", addr);
579         return 0;
580 }
581 
582 static uint64_t
583 dma_read(void *opaque, hwaddr addr, unsigned int size)
584 {
585         struct fs_dma_ctrl *ctrl = opaque;
586 	int c;
587 	uint32_t r = 0;
588 
589 	if (size != 4) {
590 		dma_rinvalid(opaque, addr);
591 	}
592 
593 	/* Make addr relative to this channel and bounded to nr regs.  */
594 	c = fs_channel(addr);
595 	addr &= 0xff;
596 	addr >>= 2;
597 	switch (addr)
598 	{
599 		case RW_STAT:
600 			r = ctrl->channels[c].state & 7;
601 			r |= ctrl->channels[c].eol << 5;
602 			r |= ctrl->channels[c].stream_cmd_src << 8;
603 			break;
604 
605 		default:
606 			r = ctrl->channels[c].regs[addr];
607 			D(printf ("%s c=%d addr=" TARGET_FMT_plx "\n",
608 				  __func__, c, addr));
609 			break;
610 	}
611 	return r;
612 }
613 
614 static void
615 dma_winvalid (void *opaque, hwaddr addr, uint32_t value)
616 {
617         hw_error("Unsupported short waccess. reg=" TARGET_FMT_plx "\n", addr);
618 }
619 
620 static void
621 dma_update_state(struct fs_dma_ctrl *ctrl, int c)
622 {
623 	if (ctrl->channels[c].regs[RW_CFG] & 2)
624 		ctrl->channels[c].state = STOPPED;
625 	if (!(ctrl->channels[c].regs[RW_CFG] & 1))
626 		ctrl->channels[c].state = RST;
627 }
628 
629 static void
630 dma_write(void *opaque, hwaddr addr,
631 	  uint64_t val64, unsigned int size)
632 {
633         struct fs_dma_ctrl *ctrl = opaque;
634 	uint32_t value = val64;
635 	int c;
636 
637 	if (size != 4) {
638 		dma_winvalid(opaque, addr, value);
639 	}
640 
641         /* Make addr relative to this channel and bounded to nr regs.  */
642 	c = fs_channel(addr);
643         addr &= 0xff;
644         addr >>= 2;
645         switch (addr)
646 	{
647 		case RW_DATA:
648 			ctrl->channels[c].regs[addr] = value;
649 			break;
650 
651 		case RW_CFG:
652 			ctrl->channels[c].regs[addr] = value;
653 			dma_update_state(ctrl, c);
654 			break;
655 		case RW_CMD:
656 			/* continue.  */
657 			if (value & ~1)
658 				printf("Invalid store to ch=%d RW_CMD %x\n",
659 				       c, value);
660 			ctrl->channels[c].regs[addr] = value;
661 			channel_continue(ctrl, c);
662 			break;
663 
664 		case RW_SAVED_DATA:
665 		case RW_SAVED_DATA_BUF:
666 		case RW_GROUP:
667 		case RW_GROUP_DOWN:
668 			ctrl->channels[c].regs[addr] = value;
669 			break;
670 
671 		case RW_ACK_INTR:
672 		case RW_INTR_MASK:
673 			ctrl->channels[c].regs[addr] = value;
674 			channel_update_irq(ctrl, c);
675 			if (addr == RW_ACK_INTR)
676 				ctrl->channels[c].regs[RW_ACK_INTR] = 0;
677 			break;
678 
679 		case RW_STREAM_CMD:
680 			if (value & ~1023)
681 				printf("Invalid store to ch=%d "
682 				       "RW_STREAMCMD %x\n",
683 				       c, value);
684 			ctrl->channels[c].regs[addr] = value;
685 			D(printf("stream_cmd ch=%d\n", c));
686 			channel_stream_cmd(ctrl, c, value);
687 			break;
688 
689 	        default:
690 			D(printf ("%s c=%d " TARGET_FMT_plx "\n",
691 				__func__, c, addr));
692 			break;
693         }
694 }
695 
696 static const MemoryRegionOps dma_ops = {
697 	.read = dma_read,
698 	.write = dma_write,
699 	.endianness = DEVICE_NATIVE_ENDIAN,
700 	.valid = {
701 		.min_access_size = 1,
702 		.max_access_size = 4
703 	}
704 };
705 
706 static int etraxfs_dmac_run(void *opaque)
707 {
708 	struct fs_dma_ctrl *ctrl = opaque;
709 	int i;
710 	int p = 0;
711 
712 	for (i = 0;
713 	     i < ctrl->nr_channels;
714 	     i++)
715 	{
716 		if (ctrl->channels[i].state == RUNNING)
717 		{
718 			if (ctrl->channels[i].input) {
719 				p += channel_in_run(ctrl, i);
720 			} else {
721 				p += channel_out_run(ctrl, i);
722 			}
723 		}
724 	}
725 	return p;
726 }
727 
728 int etraxfs_dmac_input(struct etraxfs_dma_client *client,
729 		       void *buf, int len, int eop)
730 {
731 	return channel_in_process(client->ctrl, client->channel,
732 				  buf, len, eop);
733 }
734 
735 /* Connect an IRQ line with a channel.  */
736 void etraxfs_dmac_connect(void *opaque, int c, qemu_irq *line, int input)
737 {
738 	struct fs_dma_ctrl *ctrl = opaque;
739 	ctrl->channels[c].irq = *line;
740 	ctrl->channels[c].input = input;
741 }
742 
743 void etraxfs_dmac_connect_client(void *opaque, int c,
744 				 struct etraxfs_dma_client *cl)
745 {
746 	struct fs_dma_ctrl *ctrl = opaque;
747 	cl->ctrl = ctrl;
748 	cl->channel = c;
749 	ctrl->channels[c].client = cl;
750 }
751 
752 
753 static void DMA_run(void *opaque)
754 {
755     struct fs_dma_ctrl *etraxfs_dmac = opaque;
756     int p = 1;
757 
758     if (runstate_is_running())
759         p = etraxfs_dmac_run(etraxfs_dmac);
760 
761     if (p)
762         qemu_bh_schedule_idle(etraxfs_dmac->bh);
763 }
764 
765 void *etraxfs_dmac_init(hwaddr base, int nr_channels)
766 {
767 	struct fs_dma_ctrl *ctrl = NULL;
768 
769 	ctrl = g_malloc0(sizeof *ctrl);
770 
771         ctrl->bh = qemu_bh_new(DMA_run, ctrl);
772 
773 	ctrl->nr_channels = nr_channels;
774 	ctrl->channels = g_malloc0(sizeof ctrl->channels[0] * nr_channels);
775 
776 	memory_region_init_io(&ctrl->mmio, NULL, &dma_ops, ctrl, "etraxfs-dma",
777 			      nr_channels * 0x2000);
778 	memory_region_add_subregion(get_system_memory(), base, &ctrl->mmio);
779 
780 	return ctrl;
781 }
782