xref: /openbmc/qemu/hw/dma/etraxfs_dma.c (revision 59a3a1c0)
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 
25 #include "qemu/osdep.h"
26 #include "hw/hw.h"
27 #include "hw/irq.h"
28 #include "qemu/main-loop.h"
29 #include "sysemu/runstate.h"
30 #include "exec/address-spaces.h"
31 
32 #include "hw/cris/etraxfs_dma.h"
33 
34 #define D(x)
35 
36 #define RW_DATA           (0x0 / 4)
37 #define RW_SAVED_DATA     (0x58 / 4)
38 #define RW_SAVED_DATA_BUF (0x5c / 4)
39 #define RW_GROUP          (0x60 / 4)
40 #define RW_GROUP_DOWN     (0x7c / 4)
41 #define RW_CMD            (0x80 / 4)
42 #define RW_CFG            (0x84 / 4)
43 #define RW_STAT           (0x88 / 4)
44 #define RW_INTR_MASK      (0x8c / 4)
45 #define RW_ACK_INTR       (0x90 / 4)
46 #define R_INTR            (0x94 / 4)
47 #define R_MASKED_INTR     (0x98 / 4)
48 #define RW_STREAM_CMD     (0x9c / 4)
49 
50 #define DMA_REG_MAX       (0x100 / 4)
51 
52 /* descriptors */
53 
54 // ------------------------------------------------------------ dma_descr_group
55 typedef struct dma_descr_group {
56   uint32_t                      next;
57   unsigned                      eol        : 1;
58   unsigned                      tol        : 1;
59   unsigned                      bol        : 1;
60   unsigned                                 : 1;
61   unsigned                      intr       : 1;
62   unsigned                                 : 2;
63   unsigned                      en         : 1;
64   unsigned                                 : 7;
65   unsigned                      dis        : 1;
66   unsigned                      md         : 16;
67   struct dma_descr_group       *up;
68   union {
69     struct dma_descr_context   *context;
70     struct dma_descr_group     *group;
71   }                             down;
72 } dma_descr_group;
73 
74 // ---------------------------------------------------------- dma_descr_context
75 typedef struct dma_descr_context {
76   uint32_t                      next;
77   unsigned                      eol        : 1;
78   unsigned                                 : 3;
79   unsigned                      intr       : 1;
80   unsigned                                 : 1;
81   unsigned                      store_mode : 1;
82   unsigned                      en         : 1;
83   unsigned                                 : 7;
84   unsigned                      dis        : 1;
85   unsigned                      md0        : 16;
86   unsigned                      md1;
87   unsigned                      md2;
88   unsigned                      md3;
89   unsigned                      md4;
90   uint32_t                      saved_data;
91   uint32_t                      saved_data_buf;
92 } dma_descr_context;
93 
94 // ------------------------------------------------------------- dma_descr_data
95 typedef struct dma_descr_data {
96   uint32_t                      next;
97   uint32_t                      buf;
98   unsigned                      eol        : 1;
99   unsigned                                 : 2;
100   unsigned                      out_eop    : 1;
101   unsigned                      intr       : 1;
102   unsigned                      wait       : 1;
103   unsigned                                 : 2;
104   unsigned                                 : 3;
105   unsigned                      in_eop     : 1;
106   unsigned                                 : 4;
107   unsigned                      md         : 16;
108   uint32_t                      after;
109 } dma_descr_data;
110 
111 /* Constants */
112 enum {
113   regk_dma_ack_pkt                         = 0x00000100,
114   regk_dma_anytime                         = 0x00000001,
115   regk_dma_array                           = 0x00000008,
116   regk_dma_burst                           = 0x00000020,
117   regk_dma_client                          = 0x00000002,
118   regk_dma_copy_next                       = 0x00000010,
119   regk_dma_copy_up                         = 0x00000020,
120   regk_dma_data_at_eol                     = 0x00000001,
121   regk_dma_dis_c                           = 0x00000010,
122   regk_dma_dis_g                           = 0x00000020,
123   regk_dma_idle                            = 0x00000001,
124   regk_dma_intern                          = 0x00000004,
125   regk_dma_load_c                          = 0x00000200,
126   regk_dma_load_c_n                        = 0x00000280,
127   regk_dma_load_c_next                     = 0x00000240,
128   regk_dma_load_d                          = 0x00000140,
129   regk_dma_load_g                          = 0x00000300,
130   regk_dma_load_g_down                     = 0x000003c0,
131   regk_dma_load_g_next                     = 0x00000340,
132   regk_dma_load_g_up                       = 0x00000380,
133   regk_dma_next_en                         = 0x00000010,
134   regk_dma_next_pkt                        = 0x00000010,
135   regk_dma_no                              = 0x00000000,
136   regk_dma_only_at_wait                    = 0x00000000,
137   regk_dma_restore                         = 0x00000020,
138   regk_dma_rst                             = 0x00000001,
139   regk_dma_running                         = 0x00000004,
140   regk_dma_rw_cfg_default                  = 0x00000000,
141   regk_dma_rw_cmd_default                  = 0x00000000,
142   regk_dma_rw_intr_mask_default            = 0x00000000,
143   regk_dma_rw_stat_default                 = 0x00000101,
144   regk_dma_rw_stream_cmd_default           = 0x00000000,
145   regk_dma_save_down                       = 0x00000020,
146   regk_dma_save_up                         = 0x00000020,
147   regk_dma_set_reg                         = 0x00000050,
148   regk_dma_set_w_size1                     = 0x00000190,
149   regk_dma_set_w_size2                     = 0x000001a0,
150   regk_dma_set_w_size4                     = 0x000001c0,
151   regk_dma_stopped                         = 0x00000002,
152   regk_dma_store_c                         = 0x00000002,
153   regk_dma_store_descr                     = 0x00000000,
154   regk_dma_store_g                         = 0x00000004,
155   regk_dma_store_md                        = 0x00000001,
156   regk_dma_sw                              = 0x00000008,
157   regk_dma_update_down                     = 0x00000020,
158   regk_dma_yes                             = 0x00000001
159 };
160 
161 enum dma_ch_state
162 {
163 	RST = 1,
164 	STOPPED = 2,
165 	RUNNING = 4
166 };
167 
168 struct fs_dma_channel
169 {
170 	qemu_irq irq;
171 	struct etraxfs_dma_client *client;
172 
173 	/* Internal status.  */
174 	int stream_cmd_src;
175 	enum dma_ch_state state;
176 
177 	unsigned int input : 1;
178 	unsigned int eol : 1;
179 
180 	struct dma_descr_group current_g;
181 	struct dma_descr_context current_c;
182 	struct dma_descr_data current_d;
183 
184 	/* Control registers.  */
185 	uint32_t regs[DMA_REG_MAX];
186 };
187 
188 struct fs_dma_ctrl
189 {
190 	MemoryRegion mmio;
191 	int nr_channels;
192 	struct fs_dma_channel *channels;
193 
194         QEMUBH *bh;
195 };
196 
197 static void DMA_run(void *opaque);
198 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
199 
200 static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
201 {
202 	return ctrl->channels[c].regs[reg];
203 }
204 
205 static inline int channel_stopped(struct fs_dma_ctrl *ctrl, int c)
206 {
207 	return channel_reg(ctrl, c, RW_CFG) & 2;
208 }
209 
210 static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
211 {
212 	return (channel_reg(ctrl, c, RW_CFG) & 1)
213 		&& ctrl->channels[c].client;
214 }
215 
216 static inline int fs_channel(hwaddr addr)
217 {
218 	/* Every channel has a 0x2000 ctrl register map.  */
219 	return addr >> 13;
220 }
221 
222 #ifdef USE_THIS_DEAD_CODE
223 static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
224 {
225 	hwaddr addr = channel_reg(ctrl, c, RW_GROUP);
226 
227 	/* Load and decode. FIXME: handle endianness.  */
228 	cpu_physical_memory_read (addr,
229 				  (void *) &ctrl->channels[c].current_g,
230 				  sizeof ctrl->channels[c].current_g);
231 }
232 
233 static void dump_c(int ch, struct dma_descr_context *c)
234 {
235 	printf("%s ch=%d\n", __func__, ch);
236 	printf("next=%x\n", c->next);
237 	printf("saved_data=%x\n", c->saved_data);
238 	printf("saved_data_buf=%x\n", c->saved_data_buf);
239 	printf("eol=%x\n", (uint32_t) c->eol);
240 }
241 
242 static void dump_d(int ch, struct dma_descr_data *d)
243 {
244 	printf("%s ch=%d\n", __func__, ch);
245 	printf("next=%x\n", d->next);
246 	printf("buf=%x\n", d->buf);
247 	printf("after=%x\n", d->after);
248 	printf("intr=%x\n", (uint32_t) d->intr);
249 	printf("out_eop=%x\n", (uint32_t) d->out_eop);
250 	printf("in_eop=%x\n", (uint32_t) d->in_eop);
251 	printf("eol=%x\n", (uint32_t) d->eol);
252 }
253 #endif
254 
255 static void channel_load_c(struct fs_dma_ctrl *ctrl, int c)
256 {
257 	hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
258 
259 	/* Load and decode. FIXME: handle endianness.  */
260 	cpu_physical_memory_read (addr,
261 				  (void *) &ctrl->channels[c].current_c,
262 				  sizeof ctrl->channels[c].current_c);
263 
264 	D(dump_c(c, &ctrl->channels[c].current_c));
265 	/* I guess this should update the current pos.  */
266 	ctrl->channels[c].regs[RW_SAVED_DATA] =
267 		(uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data;
268 	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
269 		(uint32_t)(unsigned long)ctrl->channels[c].current_c.saved_data_buf;
270 }
271 
272 static void channel_load_d(struct fs_dma_ctrl *ctrl, int c)
273 {
274 	hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
275 
276 	/* Load and decode. FIXME: handle endianness.  */
277 	D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
278 	cpu_physical_memory_read (addr,
279 				  (void *) &ctrl->channels[c].current_d,
280 				  sizeof ctrl->channels[c].current_d);
281 
282 	D(dump_d(c, &ctrl->channels[c].current_d));
283 	ctrl->channels[c].regs[RW_DATA] = addr;
284 }
285 
286 static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
287 {
288 	hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
289 
290 	/* Encode and store. FIXME: handle endianness.  */
291 	D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
292 	D(dump_d(c, &ctrl->channels[c].current_d));
293 	cpu_physical_memory_write (addr,
294 				  (void *) &ctrl->channels[c].current_c,
295 				  sizeof ctrl->channels[c].current_c);
296 }
297 
298 static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
299 {
300 	hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
301 
302 	/* Encode and store. FIXME: handle endianness.  */
303 	D(printf("%s ch=%d addr=" TARGET_FMT_plx "\n", __func__, c, addr));
304 	cpu_physical_memory_write (addr,
305 				  (void *) &ctrl->channels[c].current_d,
306 				  sizeof ctrl->channels[c].current_d);
307 }
308 
309 static inline void channel_stop(struct fs_dma_ctrl *ctrl, int c)
310 {
311 	/* FIXME:  */
312 }
313 
314 static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
315 {
316 	if (ctrl->channels[c].client)
317 	{
318 		ctrl->channels[c].eol = 0;
319 		ctrl->channels[c].state = RUNNING;
320 		if (!ctrl->channels[c].input)
321 			channel_out_run(ctrl, c);
322 	} else
323 		printf("WARNING: starting DMA ch %d with no client\n", c);
324 
325         qemu_bh_schedule_idle(ctrl->bh);
326 }
327 
328 static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
329 {
330 	if (!channel_en(ctrl, c)
331 	    || channel_stopped(ctrl, c)
332 	    || ctrl->channels[c].state != RUNNING
333 	    /* Only reload the current data descriptor if it has eol set.  */
334 	    || !ctrl->channels[c].current_d.eol) {
335 		D(printf("continue failed ch=%d state=%d stopped=%d en=%d eol=%d\n",
336 			 c, ctrl->channels[c].state,
337 			 channel_stopped(ctrl, c),
338 			 channel_en(ctrl,c),
339 			 ctrl->channels[c].eol));
340 		D(dump_d(c, &ctrl->channels[c].current_d));
341 		return;
342 	}
343 
344 	/* Reload the current descriptor.  */
345 	channel_load_d(ctrl, c);
346 
347 	/* If the current descriptor cleared the eol flag and we had already
348 	   reached eol state, do the continue.  */
349 	if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
350 		D(printf("continue %d ok %x\n", c,
351 			 ctrl->channels[c].current_d.next));
352 		ctrl->channels[c].regs[RW_SAVED_DATA] =
353 			(uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
354 		channel_load_d(ctrl, c);
355 		ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
356 			(uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
357 
358 		channel_start(ctrl, c);
359 	}
360 	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
361 		(uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
362 }
363 
364 static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
365 {
366 	unsigned int cmd = v & ((1 << 10) - 1);
367 
368 	D(printf("%s ch=%d cmd=%x\n",
369 		 __func__, c, cmd));
370 	if (cmd & regk_dma_load_d) {
371 		channel_load_d(ctrl, c);
372 		if (cmd & regk_dma_burst)
373 			channel_start(ctrl, c);
374 	}
375 
376 	if (cmd & regk_dma_load_c) {
377 		channel_load_c(ctrl, c);
378 	}
379 }
380 
381 static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
382 {
383 	D(printf("%s %d\n", __func__, c));
384         ctrl->channels[c].regs[R_INTR] &=
385 		~(ctrl->channels[c].regs[RW_ACK_INTR]);
386 
387         ctrl->channels[c].regs[R_MASKED_INTR] =
388 		ctrl->channels[c].regs[R_INTR]
389 		& ctrl->channels[c].regs[RW_INTR_MASK];
390 
391 	D(printf("%s: chan=%d masked_intr=%x\n", __func__,
392 		 c,
393 		 ctrl->channels[c].regs[R_MASKED_INTR]));
394 
395         qemu_set_irq(ctrl->channels[c].irq,
396 		     !!ctrl->channels[c].regs[R_MASKED_INTR]);
397 }
398 
399 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
400 {
401 	uint32_t len;
402 	uint32_t saved_data_buf;
403 	unsigned char buf[2 * 1024];
404 
405 	struct dma_context_metadata meta;
406 	bool send_context = true;
407 
408 	if (ctrl->channels[c].eol)
409 		return 0;
410 
411 	do {
412 		bool out_eop;
413 		D(printf("ch=%d buf=%x after=%x\n",
414 			 c,
415 			 (uint32_t)ctrl->channels[c].current_d.buf,
416 			 (uint32_t)ctrl->channels[c].current_d.after));
417 
418 		if (send_context) {
419 			if (ctrl->channels[c].client->client.metadata_push) {
420 				meta.metadata = ctrl->channels[c].current_d.md;
421 				ctrl->channels[c].client->client.metadata_push(
422 					ctrl->channels[c].client->client.opaque,
423 					&meta);
424 			}
425 			send_context = false;
426 		}
427 
428 		channel_load_d(ctrl, c);
429 		saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
430 		len = (uint32_t)(unsigned long)
431 			ctrl->channels[c].current_d.after;
432 		len -= saved_data_buf;
433 
434 		if (len > sizeof buf)
435 			len = sizeof buf;
436 		cpu_physical_memory_read (saved_data_buf, buf, len);
437 
438 		out_eop = ((saved_data_buf + len) ==
439 		           ctrl->channels[c].current_d.after) &&
440 			ctrl->channels[c].current_d.out_eop;
441 
442 		D(printf("channel %d pushes %x %u bytes eop=%u\n", c,
443 		         saved_data_buf, len, out_eop));
444 
445 		if (ctrl->channels[c].client->client.push) {
446                         if (len > 0) {
447 				ctrl->channels[c].client->client.push(
448 					ctrl->channels[c].client->client.opaque,
449 					buf, len, out_eop);
450 			}
451 		} else {
452 			printf("WARNING: DMA ch%d dataloss,"
453 			       " no attached client.\n", c);
454 		}
455 
456 		saved_data_buf += len;
457 
458 		if (saved_data_buf == (uint32_t)(unsigned long)
459 				ctrl->channels[c].current_d.after) {
460 			/* Done. Step to next.  */
461 			if (ctrl->channels[c].current_d.out_eop) {
462 				send_context = true;
463 			}
464 			if (ctrl->channels[c].current_d.intr) {
465 				/* data intr.  */
466 				D(printf("signal intr %d eol=%d\n",
467 					len, ctrl->channels[c].current_d.eol));
468 				ctrl->channels[c].regs[R_INTR] |= (1 << 2);
469 				channel_update_irq(ctrl, c);
470 			}
471 			channel_store_d(ctrl, c);
472 			if (ctrl->channels[c].current_d.eol) {
473 				D(printf("channel %d EOL\n", c));
474 				ctrl->channels[c].eol = 1;
475 
476 				/* Mark the context as disabled.  */
477 				ctrl->channels[c].current_c.dis = 1;
478 				channel_store_c(ctrl, c);
479 
480 				channel_stop(ctrl, c);
481 			} else {
482 				ctrl->channels[c].regs[RW_SAVED_DATA] =
483 					(uint32_t)(unsigned long)ctrl->
484 						channels[c].current_d.next;
485 				/* Load new descriptor.  */
486 				channel_load_d(ctrl, c);
487 				saved_data_buf = (uint32_t)(unsigned long)
488 					ctrl->channels[c].current_d.buf;
489 			}
490 
491 			ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
492 							saved_data_buf;
493 			D(dump_d(c, &ctrl->channels[c].current_d));
494 		}
495 		ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
496 	} while (!ctrl->channels[c].eol);
497 	return 1;
498 }
499 
500 static int channel_in_process(struct fs_dma_ctrl *ctrl, int c,
501 			      unsigned char *buf, int buflen, int eop)
502 {
503 	uint32_t len;
504 	uint32_t saved_data_buf;
505 
506 	if (ctrl->channels[c].eol == 1)
507 		return 0;
508 
509 	channel_load_d(ctrl, c);
510 	saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
511 	len = (uint32_t)(unsigned long)ctrl->channels[c].current_d.after;
512 	len -= saved_data_buf;
513 
514 	if (len > buflen)
515 		len = buflen;
516 
517 	cpu_physical_memory_write (saved_data_buf, buf, len);
518 	saved_data_buf += len;
519 
520 	if (saved_data_buf ==
521 	    (uint32_t)(unsigned long)ctrl->channels[c].current_d.after
522 	    || eop) {
523 		uint32_t r_intr = ctrl->channels[c].regs[R_INTR];
524 
525 		D(printf("in dscr end len=%d\n",
526 			 ctrl->channels[c].current_d.after
527 			 - ctrl->channels[c].current_d.buf));
528 		ctrl->channels[c].current_d.after = saved_data_buf;
529 
530 		/* Done. Step to next.  */
531 		if (ctrl->channels[c].current_d.intr) {
532 			/* TODO: signal eop to the client.  */
533 			/* data intr.  */
534 			ctrl->channels[c].regs[R_INTR] |= 3;
535 		}
536 		if (eop) {
537 			ctrl->channels[c].current_d.in_eop = 1;
538 			ctrl->channels[c].regs[R_INTR] |= 8;
539 		}
540 		if (r_intr != ctrl->channels[c].regs[R_INTR])
541 			channel_update_irq(ctrl, c);
542 
543 		channel_store_d(ctrl, c);
544 		D(dump_d(c, &ctrl->channels[c].current_d));
545 
546 		if (ctrl->channels[c].current_d.eol) {
547 			D(printf("channel %d EOL\n", c));
548 			ctrl->channels[c].eol = 1;
549 
550 			/* Mark the context as disabled.  */
551 			ctrl->channels[c].current_c.dis = 1;
552 			channel_store_c(ctrl, c);
553 
554 			channel_stop(ctrl, c);
555 		} else {
556 			ctrl->channels[c].regs[RW_SAVED_DATA] =
557 				(uint32_t)(unsigned long)ctrl->
558 					channels[c].current_d.next;
559 			/* Load new descriptor.  */
560 			channel_load_d(ctrl, c);
561 			saved_data_buf = (uint32_t)(unsigned long)
562 				ctrl->channels[c].current_d.buf;
563 		}
564 	}
565 
566 	ctrl->channels[c].regs[RW_SAVED_DATA_BUF] = saved_data_buf;
567 	return len;
568 }
569 
570 static inline int channel_in_run(struct fs_dma_ctrl *ctrl, int c)
571 {
572 	if (ctrl->channels[c].client->client.pull) {
573 		ctrl->channels[c].client->client.pull(
574 			ctrl->channels[c].client->client.opaque);
575 		return 1;
576 	} else
577 		return 0;
578 }
579 
580 static uint32_t dma_rinvalid (void *opaque, hwaddr addr)
581 {
582         hw_error("Unsupported short raccess. reg=" TARGET_FMT_plx "\n", addr);
583         return 0;
584 }
585 
586 static uint64_t
587 dma_read(void *opaque, hwaddr addr, unsigned int size)
588 {
589         struct fs_dma_ctrl *ctrl = opaque;
590 	int c;
591 	uint32_t r = 0;
592 
593 	if (size != 4) {
594 		dma_rinvalid(opaque, addr);
595 	}
596 
597 	/* Make addr relative to this channel and bounded to nr regs.  */
598 	c = fs_channel(addr);
599 	addr &= 0xff;
600 	addr >>= 2;
601 	switch (addr)
602 	{
603 		case RW_STAT:
604 			r = ctrl->channels[c].state & 7;
605 			r |= ctrl->channels[c].eol << 5;
606 			r |= ctrl->channels[c].stream_cmd_src << 8;
607 			break;
608 
609 		default:
610 			r = ctrl->channels[c].regs[addr];
611 			D(printf ("%s c=%d addr=" TARGET_FMT_plx "\n",
612 				  __func__, c, addr));
613 			break;
614 	}
615 	return r;
616 }
617 
618 static void
619 dma_winvalid (void *opaque, hwaddr addr, uint32_t value)
620 {
621         hw_error("Unsupported short waccess. reg=" TARGET_FMT_plx "\n", addr);
622 }
623 
624 static void
625 dma_update_state(struct fs_dma_ctrl *ctrl, int c)
626 {
627 	if (ctrl->channels[c].regs[RW_CFG] & 2)
628 		ctrl->channels[c].state = STOPPED;
629 	if (!(ctrl->channels[c].regs[RW_CFG] & 1))
630 		ctrl->channels[c].state = RST;
631 }
632 
633 static void
634 dma_write(void *opaque, hwaddr addr,
635 	  uint64_t val64, unsigned int size)
636 {
637         struct fs_dma_ctrl *ctrl = opaque;
638 	uint32_t value = val64;
639 	int c;
640 
641 	if (size != 4) {
642 		dma_winvalid(opaque, addr, value);
643 	}
644 
645         /* Make addr relative to this channel and bounded to nr regs.  */
646 	c = fs_channel(addr);
647         addr &= 0xff;
648         addr >>= 2;
649         switch (addr)
650 	{
651 		case RW_DATA:
652 			ctrl->channels[c].regs[addr] = value;
653 			break;
654 
655 		case RW_CFG:
656 			ctrl->channels[c].regs[addr] = value;
657 			dma_update_state(ctrl, c);
658 			break;
659 		case RW_CMD:
660 			/* continue.  */
661 			if (value & ~1)
662 				printf("Invalid store to ch=%d RW_CMD %x\n",
663 				       c, value);
664 			ctrl->channels[c].regs[addr] = value;
665 			channel_continue(ctrl, c);
666 			break;
667 
668 		case RW_SAVED_DATA:
669 		case RW_SAVED_DATA_BUF:
670 		case RW_GROUP:
671 		case RW_GROUP_DOWN:
672 			ctrl->channels[c].regs[addr] = value;
673 			break;
674 
675 		case RW_ACK_INTR:
676 		case RW_INTR_MASK:
677 			ctrl->channels[c].regs[addr] = value;
678 			channel_update_irq(ctrl, c);
679 			if (addr == RW_ACK_INTR)
680 				ctrl->channels[c].regs[RW_ACK_INTR] = 0;
681 			break;
682 
683 		case RW_STREAM_CMD:
684 			if (value & ~1023)
685 				printf("Invalid store to ch=%d "
686 				       "RW_STREAMCMD %x\n",
687 				       c, value);
688 			ctrl->channels[c].regs[addr] = value;
689 			D(printf("stream_cmd ch=%d\n", c));
690 			channel_stream_cmd(ctrl, c, value);
691 			break;
692 
693 	        default:
694 			D(printf ("%s c=%d " TARGET_FMT_plx "\n",
695 				__func__, c, addr));
696 			break;
697         }
698 }
699 
700 static const MemoryRegionOps dma_ops = {
701 	.read = dma_read,
702 	.write = dma_write,
703 	.endianness = DEVICE_NATIVE_ENDIAN,
704 	.valid = {
705 		.min_access_size = 1,
706 		.max_access_size = 4
707 	}
708 };
709 
710 static int etraxfs_dmac_run(void *opaque)
711 {
712 	struct fs_dma_ctrl *ctrl = opaque;
713 	int i;
714 	int p = 0;
715 
716 	for (i = 0;
717 	     i < ctrl->nr_channels;
718 	     i++)
719 	{
720 		if (ctrl->channels[i].state == RUNNING)
721 		{
722 			if (ctrl->channels[i].input) {
723 				p += channel_in_run(ctrl, i);
724 			} else {
725 				p += channel_out_run(ctrl, i);
726 			}
727 		}
728 	}
729 	return p;
730 }
731 
732 int etraxfs_dmac_input(struct etraxfs_dma_client *client,
733 		       void *buf, int len, int eop)
734 {
735 	return channel_in_process(client->ctrl, client->channel,
736 				  buf, len, eop);
737 }
738 
739 /* Connect an IRQ line with a channel.  */
740 void etraxfs_dmac_connect(void *opaque, int c, qemu_irq *line, int input)
741 {
742 	struct fs_dma_ctrl *ctrl = opaque;
743 	ctrl->channels[c].irq = *line;
744 	ctrl->channels[c].input = input;
745 }
746 
747 void etraxfs_dmac_connect_client(void *opaque, int c,
748 				 struct etraxfs_dma_client *cl)
749 {
750 	struct fs_dma_ctrl *ctrl = opaque;
751 	cl->ctrl = ctrl;
752 	cl->channel = c;
753 	ctrl->channels[c].client = cl;
754 }
755 
756 
757 static void DMA_run(void *opaque)
758 {
759     struct fs_dma_ctrl *etraxfs_dmac = opaque;
760     int p = 1;
761 
762     if (runstate_is_running())
763         p = etraxfs_dmac_run(etraxfs_dmac);
764 
765     if (p)
766         qemu_bh_schedule_idle(etraxfs_dmac->bh);
767 }
768 
769 void *etraxfs_dmac_init(hwaddr base, int nr_channels)
770 {
771 	struct fs_dma_ctrl *ctrl = NULL;
772 
773 	ctrl = g_malloc0(sizeof *ctrl);
774 
775         ctrl->bh = qemu_bh_new(DMA_run, ctrl);
776 
777 	ctrl->nr_channels = nr_channels;
778 	ctrl->channels = g_malloc0(sizeof ctrl->channels[0] * nr_channels);
779 
780 	memory_region_init_io(&ctrl->mmio, NULL, &dma_ops, ctrl, "etraxfs-dma",
781 			      nr_channels * 0x2000);
782 	memory_region_add_subregion(get_system_memory(), base, &ctrl->mmio);
783 
784 	return ctrl;
785 }
786