xref: /openbmc/qemu/hw/dma/etraxfs_dma.c (revision 3b894b69)
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 #include "exec/memory.h"
32 
33 #include "hw/cris/etraxfs_dma.h"
34 
35 #define D(x)
36 
37 #define RW_DATA           (0x0 / 4)
38 #define RW_SAVED_DATA     (0x58 / 4)
39 #define RW_SAVED_DATA_BUF (0x5c / 4)
40 #define RW_GROUP          (0x60 / 4)
41 #define RW_GROUP_DOWN     (0x7c / 4)
42 #define RW_CMD            (0x80 / 4)
43 #define RW_CFG            (0x84 / 4)
44 #define RW_STAT           (0x88 / 4)
45 #define RW_INTR_MASK      (0x8c / 4)
46 #define RW_ACK_INTR       (0x90 / 4)
47 #define R_INTR            (0x94 / 4)
48 #define R_MASKED_INTR     (0x98 / 4)
49 #define RW_STREAM_CMD     (0x9c / 4)
50 
51 #define DMA_REG_MAX       (0x100 / 4)
52 
53 /* descriptors */
54 
55 // ------------------------------------------------------------ dma_descr_group
56 typedef struct dma_descr_group {
57   uint32_t                      next;
58   unsigned                      eol        : 1;
59   unsigned                      tol        : 1;
60   unsigned                      bol        : 1;
61   unsigned                                 : 1;
62   unsigned                      intr       : 1;
63   unsigned                                 : 2;
64   unsigned                      en         : 1;
65   unsigned                                 : 7;
66   unsigned                      dis        : 1;
67   unsigned                      md         : 16;
68   struct dma_descr_group       *up;
69   union {
70     struct dma_descr_context   *context;
71     struct dma_descr_group     *group;
72   }                             down;
73 } dma_descr_group;
74 
75 // ---------------------------------------------------------- dma_descr_context
76 typedef struct dma_descr_context {
77   uint32_t                      next;
78   unsigned                      eol        : 1;
79   unsigned                                 : 3;
80   unsigned                      intr       : 1;
81   unsigned                                 : 1;
82   unsigned                      store_mode : 1;
83   unsigned                      en         : 1;
84   unsigned                                 : 7;
85   unsigned                      dis        : 1;
86   unsigned                      md0        : 16;
87   unsigned                      md1;
88   unsigned                      md2;
89   unsigned                      md3;
90   unsigned                      md4;
91   uint32_t                      saved_data;
92   uint32_t                      saved_data_buf;
93 } dma_descr_context;
94 
95 // ------------------------------------------------------------- dma_descr_data
96 typedef struct dma_descr_data {
97   uint32_t                      next;
98   uint32_t                      buf;
99   unsigned                      eol        : 1;
100   unsigned                                 : 2;
101   unsigned                      out_eop    : 1;
102   unsigned                      intr       : 1;
103   unsigned                      wait       : 1;
104   unsigned                                 : 2;
105   unsigned                                 : 3;
106   unsigned                      in_eop     : 1;
107   unsigned                                 : 4;
108   unsigned                      md         : 16;
109   uint32_t                      after;
110 } dma_descr_data;
111 
112 /* Constants */
113 enum {
114   regk_dma_ack_pkt                         = 0x00000100,
115   regk_dma_anytime                         = 0x00000001,
116   regk_dma_array                           = 0x00000008,
117   regk_dma_burst                           = 0x00000020,
118   regk_dma_client                          = 0x00000002,
119   regk_dma_copy_next                       = 0x00000010,
120   regk_dma_copy_up                         = 0x00000020,
121   regk_dma_data_at_eol                     = 0x00000001,
122   regk_dma_dis_c                           = 0x00000010,
123   regk_dma_dis_g                           = 0x00000020,
124   regk_dma_idle                            = 0x00000001,
125   regk_dma_intern                          = 0x00000004,
126   regk_dma_load_c                          = 0x00000200,
127   regk_dma_load_c_n                        = 0x00000280,
128   regk_dma_load_c_next                     = 0x00000240,
129   regk_dma_load_d                          = 0x00000140,
130   regk_dma_load_g                          = 0x00000300,
131   regk_dma_load_g_down                     = 0x000003c0,
132   regk_dma_load_g_next                     = 0x00000340,
133   regk_dma_load_g_up                       = 0x00000380,
134   regk_dma_next_en                         = 0x00000010,
135   regk_dma_next_pkt                        = 0x00000010,
136   regk_dma_no                              = 0x00000000,
137   regk_dma_only_at_wait                    = 0x00000000,
138   regk_dma_restore                         = 0x00000020,
139   regk_dma_rst                             = 0x00000001,
140   regk_dma_running                         = 0x00000004,
141   regk_dma_rw_cfg_default                  = 0x00000000,
142   regk_dma_rw_cmd_default                  = 0x00000000,
143   regk_dma_rw_intr_mask_default            = 0x00000000,
144   regk_dma_rw_stat_default                 = 0x00000101,
145   regk_dma_rw_stream_cmd_default           = 0x00000000,
146   regk_dma_save_down                       = 0x00000020,
147   regk_dma_save_up                         = 0x00000020,
148   regk_dma_set_reg                         = 0x00000050,
149   regk_dma_set_w_size1                     = 0x00000190,
150   regk_dma_set_w_size2                     = 0x000001a0,
151   regk_dma_set_w_size4                     = 0x000001c0,
152   regk_dma_stopped                         = 0x00000002,
153   regk_dma_store_c                         = 0x00000002,
154   regk_dma_store_descr                     = 0x00000000,
155   regk_dma_store_g                         = 0x00000004,
156   regk_dma_store_md                        = 0x00000001,
157   regk_dma_sw                              = 0x00000008,
158   regk_dma_update_down                     = 0x00000020,
159   regk_dma_yes                             = 0x00000001
160 };
161 
162 enum dma_ch_state
163 {
164     RST = 1,
165     STOPPED = 2,
166     RUNNING = 4
167 };
168 
169 struct fs_dma_channel
170 {
171     qemu_irq irq;
172     struct etraxfs_dma_client *client;
173 
174     /* Internal status.  */
175     int stream_cmd_src;
176     enum dma_ch_state state;
177 
178     unsigned int input : 1;
179     unsigned int eol : 1;
180 
181     struct dma_descr_group current_g;
182     struct dma_descr_context current_c;
183     struct dma_descr_data current_d;
184 
185     /* Control registers.  */
186     uint32_t regs[DMA_REG_MAX];
187 };
188 
189 struct fs_dma_ctrl
190 {
191     MemoryRegion mmio;
192     int nr_channels;
193     struct fs_dma_channel *channels;
194 
195     QEMUBH *bh;
196 };
197 
198 static void DMA_run(void *opaque);
199 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c);
200 
201 static inline uint32_t channel_reg(struct fs_dma_ctrl *ctrl, int c, int reg)
202 {
203     return ctrl->channels[c].regs[reg];
204 }
205 
206 static inline int channel_stopped(struct fs_dma_ctrl *ctrl, int c)
207 {
208     return channel_reg(ctrl, c, RW_CFG) & 2;
209 }
210 
211 static inline int channel_en(struct fs_dma_ctrl *ctrl, int c)
212 {
213     return (channel_reg(ctrl, c, RW_CFG) & 1)
214             && ctrl->channels[c].client;
215 }
216 
217 static inline int fs_channel(hwaddr addr)
218 {
219     /* Every channel has a 0x2000 ctrl register map.  */
220     return addr >> 13;
221 }
222 
223 #ifdef USE_THIS_DEAD_CODE
224 static void channel_load_g(struct fs_dma_ctrl *ctrl, int c)
225 {
226     hwaddr addr = channel_reg(ctrl, c, RW_GROUP);
227 
228     /* Load and decode. FIXME: handle endianness.  */
229     cpu_physical_memory_read(addr, &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, &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=" HWADDR_FMT_plx "\n", __func__, c, addr));
277     cpu_physical_memory_read(addr, &ctrl->channels[c].current_d,
278                              sizeof(ctrl->channels[c].current_d));
279 
280     D(dump_d(c, &ctrl->channels[c].current_d));
281     ctrl->channels[c].regs[RW_DATA] = addr;
282 }
283 
284 static void channel_store_c(struct fs_dma_ctrl *ctrl, int c)
285 {
286     hwaddr addr = channel_reg(ctrl, c, RW_GROUP_DOWN);
287 
288     /* Encode and store. FIXME: handle endianness.  */
289     D(printf("%s ch=%d addr=" HWADDR_FMT_plx "\n", __func__, c, addr));
290     D(dump_d(c, &ctrl->channels[c].current_d));
291     cpu_physical_memory_write(addr, &ctrl->channels[c].current_c,
292                               sizeof(ctrl->channels[c].current_c));
293 }
294 
295 static void channel_store_d(struct fs_dma_ctrl *ctrl, int c)
296 {
297     hwaddr addr = channel_reg(ctrl, c, RW_SAVED_DATA);
298 
299     /* Encode and store. FIXME: handle endianness.  */
300     D(printf("%s ch=%d addr=" HWADDR_FMT_plx "\n", __func__, c, addr));
301     cpu_physical_memory_write(addr, &ctrl->channels[c].current_d,
302                               sizeof(ctrl->channels[c].current_d));
303 }
304 
305 static inline void channel_stop(struct fs_dma_ctrl *ctrl, int c)
306 {
307     /* FIXME:  */
308 }
309 
310 static inline void channel_start(struct fs_dma_ctrl *ctrl, int c)
311 {
312     if (ctrl->channels[c].client)
313     {
314         ctrl->channels[c].eol = 0;
315         ctrl->channels[c].state = RUNNING;
316         if (!ctrl->channels[c].input)
317             channel_out_run(ctrl, c);
318     } else
319         printf("WARNING: starting DMA ch %d with no client\n", c);
320 
321     qemu_bh_schedule_idle(ctrl->bh);
322 }
323 
324 static void channel_continue(struct fs_dma_ctrl *ctrl, int c)
325 {
326     if (!channel_en(ctrl, c)
327         || channel_stopped(ctrl, c)
328         || ctrl->channels[c].state != RUNNING
329         /* Only reload the current data descriptor if it has eol set.  */
330         || !ctrl->channels[c].current_d.eol) {
331         D(printf("continue failed ch=%d state=%d stopped=%d en=%d eol=%d\n",
332                  c, ctrl->channels[c].state,
333                  channel_stopped(ctrl, c),
334                  channel_en(ctrl,c),
335                  ctrl->channels[c].eol));
336         D(dump_d(c, &ctrl->channels[c].current_d));
337         return;
338     }
339 
340     /* Reload the current descriptor.  */
341     channel_load_d(ctrl, c);
342 
343     /* If the current descriptor cleared the eol flag and we had already
344        reached eol state, do the continue.  */
345     if (!ctrl->channels[c].current_d.eol && ctrl->channels[c].eol) {
346         D(printf("continue %d ok %x\n", c,
347                  ctrl->channels[c].current_d.next));
348         ctrl->channels[c].regs[RW_SAVED_DATA] =
349             (uint32_t)(unsigned long)ctrl->channels[c].current_d.next;
350         channel_load_d(ctrl, c);
351         ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
352             (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
353 
354         channel_start(ctrl, c);
355     }
356     ctrl->channels[c].regs[RW_SAVED_DATA_BUF] =
357         (uint32_t)(unsigned long)ctrl->channels[c].current_d.buf;
358 }
359 
360 static void channel_stream_cmd(struct fs_dma_ctrl *ctrl, int c, uint32_t v)
361 {
362     unsigned int cmd = v & ((1 << 10) - 1);
363 
364     D(printf("%s ch=%d cmd=%x\n",
365              __func__, c, cmd));
366     if (cmd & regk_dma_load_d) {
367         channel_load_d(ctrl, c);
368         if (cmd & regk_dma_burst)
369             channel_start(ctrl, c);
370     }
371 
372     if (cmd & regk_dma_load_c) {
373         channel_load_c(ctrl, c);
374     }
375 }
376 
377 static void channel_update_irq(struct fs_dma_ctrl *ctrl, int c)
378 {
379     D(printf("%s %d\n", __func__, c));
380     ctrl->channels[c].regs[R_INTR] &=
381         ~(ctrl->channels[c].regs[RW_ACK_INTR]);
382 
383     ctrl->channels[c].regs[R_MASKED_INTR] =
384         ctrl->channels[c].regs[R_INTR]
385         & ctrl->channels[c].regs[RW_INTR_MASK];
386 
387     D(printf("%s: chan=%d masked_intr=%x\n", __func__,
388              c,
389              ctrl->channels[c].regs[R_MASKED_INTR]));
390 
391     qemu_set_irq(ctrl->channels[c].irq,
392                  !!ctrl->channels[c].regs[R_MASKED_INTR]);
393 }
394 
395 static int channel_out_run(struct fs_dma_ctrl *ctrl, int c)
396 {
397     uint32_t len;
398     uint32_t saved_data_buf;
399     unsigned char buf[2 * 1024];
400 
401     struct dma_context_metadata meta;
402     bool send_context = true;
403 
404     if (ctrl->channels[c].eol)
405         return 0;
406 
407     do {
408         bool out_eop;
409         D(printf("ch=%d buf=%x after=%x\n",
410                  c,
411                  (uint32_t)ctrl->channels[c].current_d.buf,
412                  (uint32_t)ctrl->channels[c].current_d.after));
413 
414         if (send_context) {
415             if (ctrl->channels[c].client->client.metadata_push) {
416                 meta.metadata = ctrl->channels[c].current_d.md;
417                 ctrl->channels[c].client->client.metadata_push(
418                     ctrl->channels[c].client->client.opaque,
419                     &meta);
420             }
421             send_context = false;
422         }
423 
424         channel_load_d(ctrl, c);
425         saved_data_buf = channel_reg(ctrl, c, RW_SAVED_DATA_BUF);
426         len = (uint32_t)(unsigned long)
427             ctrl->channels[c].current_d.after;
428         len -= saved_data_buf;
429 
430         if (len > sizeof buf)
431             len = sizeof buf;
432         cpu_physical_memory_read (saved_data_buf, buf, len);
433 
434         out_eop = ((saved_data_buf + len) ==
435                    ctrl->channels[c].current_d.after) &&
436                    ctrl->channels[c].current_d.out_eop;
437 
438         D(printf("channel %d pushes %x %u bytes eop=%u\n", c,
439                  saved_data_buf, len, out_eop));
440 
441         if (ctrl->channels[c].client->client.push) {
442             if (len > 0) {
443                 ctrl->channels[c].client->client.push(
444                     ctrl->channels[c].client->client.opaque,
445                     buf, len, out_eop);
446             }
447         } else {
448             printf("WARNING: DMA ch%d dataloss,"
449                    " no attached client.\n", c);
450         }
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=" HWADDR_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=" HWADDR_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=" HWADDR_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 " HWADDR_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