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Merge tag 'iio-fixes-for-4.6b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23...
[deliverable/linux.git] / drivers / dma / mpc512x_dma.c
1 /*
2 * Copyright (C) Freescale Semicondutor, Inc. 2007, 2008.
3 * Copyright (C) Semihalf 2009
4 * Copyright (C) Ilya Yanok, Emcraft Systems 2010
5 * Copyright (C) Alexander Popov, Promcontroller 2014
6 *
7 * Written by Piotr Ziecik <kosmo@semihalf.com>. Hardware description
8 * (defines, structures and comments) was taken from MPC5121 DMA driver
9 * written by Hongjun Chen <hong-jun.chen@freescale.com>.
10 *
11 * Approved as OSADL project by a majority of OSADL members and funded
12 * by OSADL membership fees in 2009; for details see www.osadl.org.
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at your option)
17 * any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but WITHOUT
20 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22 * more details.
23 *
24 * The full GNU General Public License is included in this distribution in the
25 * file called COPYING.
26 */
27
28 /*
29 * MPC512x and MPC8308 DMA driver. It supports
30 * memory to memory data transfers (tested using dmatest module) and
31 * data transfers between memory and peripheral I/O memory
32 * by means of slave scatter/gather with these limitations:
33 * - chunked transfers (described by s/g lists with more than one item)
34 * are refused as long as proper support for scatter/gather is missing;
35 * - transfers on MPC8308 always start from software as this SoC appears
36 * not to have external request lines for peripheral flow control;
37 * - only peripheral devices with 4-byte FIFO access register are supported;
38 * - minimal memory <-> I/O memory transfer chunk is 4 bytes and consequently
39 * source and destination addresses must be 4-byte aligned
40 * and transfer size must be aligned on (4 * maxburst) boundary;
41 */
42
43 #include <linux/module.h>
44 #include <linux/dmaengine.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/interrupt.h>
47 #include <linux/io.h>
48 #include <linux/slab.h>
49 #include <linux/of_address.h>
50 #include <linux/of_device.h>
51 #include <linux/of_irq.h>
52 #include <linux/of_dma.h>
53 #include <linux/of_platform.h>
54
55 #include <linux/random.h>
56
57 #include "dmaengine.h"
58
59 /* Number of DMA Transfer descriptors allocated per channel */
60 #define MPC_DMA_DESCRIPTORS 64
61
62 /* Macro definitions */
63 #define MPC_DMA_TCD_OFFSET 0x1000
64
65 /*
66 * Maximum channel counts for individual hardware variants
67 * and the maximum channel count over all supported controllers,
68 * used for data structure size
69 */
70 #define MPC8308_DMACHAN_MAX 16
71 #define MPC512x_DMACHAN_MAX 64
72 #define MPC_DMA_CHANNELS 64
73
74 /* Arbitration mode of group and channel */
75 #define MPC_DMA_DMACR_EDCG (1 << 31)
76 #define MPC_DMA_DMACR_ERGA (1 << 3)
77 #define MPC_DMA_DMACR_ERCA (1 << 2)
78
79 /* Error codes */
80 #define MPC_DMA_DMAES_VLD (1 << 31)
81 #define MPC_DMA_DMAES_GPE (1 << 15)
82 #define MPC_DMA_DMAES_CPE (1 << 14)
83 #define MPC_DMA_DMAES_ERRCHN(err) \
84 (((err) >> 8) & 0x3f)
85 #define MPC_DMA_DMAES_SAE (1 << 7)
86 #define MPC_DMA_DMAES_SOE (1 << 6)
87 #define MPC_DMA_DMAES_DAE (1 << 5)
88 #define MPC_DMA_DMAES_DOE (1 << 4)
89 #define MPC_DMA_DMAES_NCE (1 << 3)
90 #define MPC_DMA_DMAES_SGE (1 << 2)
91 #define MPC_DMA_DMAES_SBE (1 << 1)
92 #define MPC_DMA_DMAES_DBE (1 << 0)
93
94 #define MPC_DMA_DMAGPOR_SNOOP_ENABLE (1 << 6)
95
96 #define MPC_DMA_TSIZE_1 0x00
97 #define MPC_DMA_TSIZE_2 0x01
98 #define MPC_DMA_TSIZE_4 0x02
99 #define MPC_DMA_TSIZE_16 0x04
100 #define MPC_DMA_TSIZE_32 0x05
101
102 /* MPC5121 DMA engine registers */
103 struct __attribute__ ((__packed__)) mpc_dma_regs {
104 /* 0x00 */
105 u32 dmacr; /* DMA control register */
106 u32 dmaes; /* DMA error status */
107 /* 0x08 */
108 u32 dmaerqh; /* DMA enable request high(channels 63~32) */
109 u32 dmaerql; /* DMA enable request low(channels 31~0) */
110 u32 dmaeeih; /* DMA enable error interrupt high(ch63~32) */
111 u32 dmaeeil; /* DMA enable error interrupt low(ch31~0) */
112 /* 0x18 */
113 u8 dmaserq; /* DMA set enable request */
114 u8 dmacerq; /* DMA clear enable request */
115 u8 dmaseei; /* DMA set enable error interrupt */
116 u8 dmaceei; /* DMA clear enable error interrupt */
117 /* 0x1c */
118 u8 dmacint; /* DMA clear interrupt request */
119 u8 dmacerr; /* DMA clear error */
120 u8 dmassrt; /* DMA set start bit */
121 u8 dmacdne; /* DMA clear DONE status bit */
122 /* 0x20 */
123 u32 dmainth; /* DMA interrupt request high(ch63~32) */
124 u32 dmaintl; /* DMA interrupt request low(ch31~0) */
125 u32 dmaerrh; /* DMA error high(ch63~32) */
126 u32 dmaerrl; /* DMA error low(ch31~0) */
127 /* 0x30 */
128 u32 dmahrsh; /* DMA hw request status high(ch63~32) */
129 u32 dmahrsl; /* DMA hardware request status low(ch31~0) */
130 union {
131 u32 dmaihsa; /* DMA interrupt high select AXE(ch63~32) */
132 u32 dmagpor; /* (General purpose register on MPC8308) */
133 };
134 u32 dmailsa; /* DMA interrupt low select AXE(ch31~0) */
135 /* 0x40 ~ 0xff */
136 u32 reserve0[48]; /* Reserved */
137 /* 0x100 */
138 u8 dchpri[MPC_DMA_CHANNELS];
139 /* DMA channels(0~63) priority */
140 };
141
142 struct __attribute__ ((__packed__)) mpc_dma_tcd {
143 /* 0x00 */
144 u32 saddr; /* Source address */
145
146 u32 smod:5; /* Source address modulo */
147 u32 ssize:3; /* Source data transfer size */
148 u32 dmod:5; /* Destination address modulo */
149 u32 dsize:3; /* Destination data transfer size */
150 u32 soff:16; /* Signed source address offset */
151
152 /* 0x08 */
153 u32 nbytes; /* Inner "minor" byte count */
154 u32 slast; /* Last source address adjustment */
155 u32 daddr; /* Destination address */
156
157 /* 0x14 */
158 u32 citer_elink:1; /* Enable channel-to-channel linking on
159 * minor loop complete
160 */
161 u32 citer_linkch:6; /* Link channel for minor loop complete */
162 u32 citer:9; /* Current "major" iteration count */
163 u32 doff:16; /* Signed destination address offset */
164
165 /* 0x18 */
166 u32 dlast_sga; /* Last Destination address adjustment/scatter
167 * gather address
168 */
169
170 /* 0x1c */
171 u32 biter_elink:1; /* Enable channel-to-channel linking on major
172 * loop complete
173 */
174 u32 biter_linkch:6;
175 u32 biter:9; /* Beginning "major" iteration count */
176 u32 bwc:2; /* Bandwidth control */
177 u32 major_linkch:6; /* Link channel number */
178 u32 done:1; /* Channel done */
179 u32 active:1; /* Channel active */
180 u32 major_elink:1; /* Enable channel-to-channel linking on major
181 * loop complete
182 */
183 u32 e_sg:1; /* Enable scatter/gather processing */
184 u32 d_req:1; /* Disable request */
185 u32 int_half:1; /* Enable an interrupt when major counter is
186 * half complete
187 */
188 u32 int_maj:1; /* Enable an interrupt when major iteration
189 * count completes
190 */
191 u32 start:1; /* Channel start */
192 };
193
194 struct mpc_dma_desc {
195 struct dma_async_tx_descriptor desc;
196 struct mpc_dma_tcd *tcd;
197 dma_addr_t tcd_paddr;
198 int error;
199 struct list_head node;
200 int will_access_peripheral;
201 };
202
203 struct mpc_dma_chan {
204 struct dma_chan chan;
205 struct list_head free;
206 struct list_head prepared;
207 struct list_head queued;
208 struct list_head active;
209 struct list_head completed;
210 struct mpc_dma_tcd *tcd;
211 dma_addr_t tcd_paddr;
212
213 /* Settings for access to peripheral FIFO */
214 dma_addr_t src_per_paddr;
215 u32 src_tcd_nunits;
216 dma_addr_t dst_per_paddr;
217 u32 dst_tcd_nunits;
218
219 /* Lock for this structure */
220 spinlock_t lock;
221 };
222
223 struct mpc_dma {
224 struct dma_device dma;
225 struct tasklet_struct tasklet;
226 struct mpc_dma_chan channels[MPC_DMA_CHANNELS];
227 struct mpc_dma_regs __iomem *regs;
228 struct mpc_dma_tcd __iomem *tcd;
229 int irq;
230 int irq2;
231 uint error_status;
232 int is_mpc8308;
233
234 /* Lock for error_status field in this structure */
235 spinlock_t error_status_lock;
236 };
237
238 #define DRV_NAME "mpc512x_dma"
239
240 /* Convert struct dma_chan to struct mpc_dma_chan */
241 static inline struct mpc_dma_chan *dma_chan_to_mpc_dma_chan(struct dma_chan *c)
242 {
243 return container_of(c, struct mpc_dma_chan, chan);
244 }
245
246 /* Convert struct dma_chan to struct mpc_dma */
247 static inline struct mpc_dma *dma_chan_to_mpc_dma(struct dma_chan *c)
248 {
249 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(c);
250 return container_of(mchan, struct mpc_dma, channels[c->chan_id]);
251 }
252
253 /*
254 * Execute all queued DMA descriptors.
255 *
256 * Following requirements must be met while calling mpc_dma_execute():
257 * a) mchan->lock is acquired,
258 * b) mchan->active list is empty,
259 * c) mchan->queued list contains at least one entry.
260 */
261 static void mpc_dma_execute(struct mpc_dma_chan *mchan)
262 {
263 struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan);
264 struct mpc_dma_desc *first = NULL;
265 struct mpc_dma_desc *prev = NULL;
266 struct mpc_dma_desc *mdesc;
267 int cid = mchan->chan.chan_id;
268
269 while (!list_empty(&mchan->queued)) {
270 mdesc = list_first_entry(&mchan->queued,
271 struct mpc_dma_desc, node);
272 /*
273 * Grab either several mem-to-mem transfer descriptors
274 * or one peripheral transfer descriptor,
275 * don't mix mem-to-mem and peripheral transfer descriptors
276 * within the same 'active' list.
277 */
278 if (mdesc->will_access_peripheral) {
279 if (list_empty(&mchan->active))
280 list_move_tail(&mdesc->node, &mchan->active);
281 break;
282 } else {
283 list_move_tail(&mdesc->node, &mchan->active);
284 }
285 }
286
287 /* Chain descriptors into one transaction */
288 list_for_each_entry(mdesc, &mchan->active, node) {
289 if (!first)
290 first = mdesc;
291
292 if (!prev) {
293 prev = mdesc;
294 continue;
295 }
296
297 prev->tcd->dlast_sga = mdesc->tcd_paddr;
298 prev->tcd->e_sg = 1;
299 mdesc->tcd->start = 1;
300
301 prev = mdesc;
302 }
303
304 prev->tcd->int_maj = 1;
305
306 /* Send first descriptor in chain into hardware */
307 memcpy_toio(&mdma->tcd[cid], first->tcd, sizeof(struct mpc_dma_tcd));
308
309 if (first != prev)
310 mdma->tcd[cid].e_sg = 1;
311
312 if (mdma->is_mpc8308) {
313 /* MPC8308, no request lines, software initiated start */
314 out_8(&mdma->regs->dmassrt, cid);
315 } else if (first->will_access_peripheral) {
316 /* Peripherals involved, start by external request signal */
317 out_8(&mdma->regs->dmaserq, cid);
318 } else {
319 /* Memory to memory transfer, software initiated start */
320 out_8(&mdma->regs->dmassrt, cid);
321 }
322 }
323
324 /* Handle interrupt on one half of DMA controller (32 channels) */
325 static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off)
326 {
327 struct mpc_dma_chan *mchan;
328 struct mpc_dma_desc *mdesc;
329 u32 status = is | es;
330 int ch;
331
332 while ((ch = fls(status) - 1) >= 0) {
333 status &= ~(1 << ch);
334 mchan = &mdma->channels[ch + off];
335
336 spin_lock(&mchan->lock);
337
338 out_8(&mdma->regs->dmacint, ch + off);
339 out_8(&mdma->regs->dmacerr, ch + off);
340
341 /* Check error status */
342 if (es & (1 << ch))
343 list_for_each_entry(mdesc, &mchan->active, node)
344 mdesc->error = -EIO;
345
346 /* Execute queued descriptors */
347 list_splice_tail_init(&mchan->active, &mchan->completed);
348 if (!list_empty(&mchan->queued))
349 mpc_dma_execute(mchan);
350
351 spin_unlock(&mchan->lock);
352 }
353 }
354
355 /* Interrupt handler */
356 static irqreturn_t mpc_dma_irq(int irq, void *data)
357 {
358 struct mpc_dma *mdma = data;
359 uint es;
360
361 /* Save error status register */
362 es = in_be32(&mdma->regs->dmaes);
363 spin_lock(&mdma->error_status_lock);
364 if ((es & MPC_DMA_DMAES_VLD) && mdma->error_status == 0)
365 mdma->error_status = es;
366 spin_unlock(&mdma->error_status_lock);
367
368 /* Handle interrupt on each channel */
369 if (mdma->dma.chancnt > 32) {
370 mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmainth),
371 in_be32(&mdma->regs->dmaerrh), 32);
372 }
373 mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl),
374 in_be32(&mdma->regs->dmaerrl), 0);
375
376 /* Schedule tasklet */
377 tasklet_schedule(&mdma->tasklet);
378
379 return IRQ_HANDLED;
380 }
381
382 /* process completed descriptors */
383 static void mpc_dma_process_completed(struct mpc_dma *mdma)
384 {
385 dma_cookie_t last_cookie = 0;
386 struct mpc_dma_chan *mchan;
387 struct mpc_dma_desc *mdesc;
388 struct dma_async_tx_descriptor *desc;
389 unsigned long flags;
390 LIST_HEAD(list);
391 int i;
392
393 for (i = 0; i < mdma->dma.chancnt; i++) {
394 mchan = &mdma->channels[i];
395
396 /* Get all completed descriptors */
397 spin_lock_irqsave(&mchan->lock, flags);
398 if (!list_empty(&mchan->completed))
399 list_splice_tail_init(&mchan->completed, &list);
400 spin_unlock_irqrestore(&mchan->lock, flags);
401
402 if (list_empty(&list))
403 continue;
404
405 /* Execute callbacks and run dependencies */
406 list_for_each_entry(mdesc, &list, node) {
407 desc = &mdesc->desc;
408
409 if (desc->callback)
410 desc->callback(desc->callback_param);
411
412 last_cookie = desc->cookie;
413 dma_run_dependencies(desc);
414 }
415
416 /* Free descriptors */
417 spin_lock_irqsave(&mchan->lock, flags);
418 list_splice_tail_init(&list, &mchan->free);
419 mchan->chan.completed_cookie = last_cookie;
420 spin_unlock_irqrestore(&mchan->lock, flags);
421 }
422 }
423
424 /* DMA Tasklet */
425 static void mpc_dma_tasklet(unsigned long data)
426 {
427 struct mpc_dma *mdma = (void *)data;
428 unsigned long flags;
429 uint es;
430
431 spin_lock_irqsave(&mdma->error_status_lock, flags);
432 es = mdma->error_status;
433 mdma->error_status = 0;
434 spin_unlock_irqrestore(&mdma->error_status_lock, flags);
435
436 /* Print nice error report */
437 if (es) {
438 dev_err(mdma->dma.dev,
439 "Hardware reported following error(s) on channel %u:\n",
440 MPC_DMA_DMAES_ERRCHN(es));
441
442 if (es & MPC_DMA_DMAES_GPE)
443 dev_err(mdma->dma.dev, "- Group Priority Error\n");
444 if (es & MPC_DMA_DMAES_CPE)
445 dev_err(mdma->dma.dev, "- Channel Priority Error\n");
446 if (es & MPC_DMA_DMAES_SAE)
447 dev_err(mdma->dma.dev, "- Source Address Error\n");
448 if (es & MPC_DMA_DMAES_SOE)
449 dev_err(mdma->dma.dev, "- Source Offset"
450 " Configuration Error\n");
451 if (es & MPC_DMA_DMAES_DAE)
452 dev_err(mdma->dma.dev, "- Destination Address"
453 " Error\n");
454 if (es & MPC_DMA_DMAES_DOE)
455 dev_err(mdma->dma.dev, "- Destination Offset"
456 " Configuration Error\n");
457 if (es & MPC_DMA_DMAES_NCE)
458 dev_err(mdma->dma.dev, "- NBytes/Citter"
459 " Configuration Error\n");
460 if (es & MPC_DMA_DMAES_SGE)
461 dev_err(mdma->dma.dev, "- Scatter/Gather"
462 " Configuration Error\n");
463 if (es & MPC_DMA_DMAES_SBE)
464 dev_err(mdma->dma.dev, "- Source Bus Error\n");
465 if (es & MPC_DMA_DMAES_DBE)
466 dev_err(mdma->dma.dev, "- Destination Bus Error\n");
467 }
468
469 mpc_dma_process_completed(mdma);
470 }
471
472 /* Submit descriptor to hardware */
473 static dma_cookie_t mpc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
474 {
475 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(txd->chan);
476 struct mpc_dma_desc *mdesc;
477 unsigned long flags;
478 dma_cookie_t cookie;
479
480 mdesc = container_of(txd, struct mpc_dma_desc, desc);
481
482 spin_lock_irqsave(&mchan->lock, flags);
483
484 /* Move descriptor to queue */
485 list_move_tail(&mdesc->node, &mchan->queued);
486
487 /* If channel is idle, execute all queued descriptors */
488 if (list_empty(&mchan->active))
489 mpc_dma_execute(mchan);
490
491 /* Update cookie */
492 cookie = dma_cookie_assign(txd);
493 spin_unlock_irqrestore(&mchan->lock, flags);
494
495 return cookie;
496 }
497
498 /* Alloc channel resources */
499 static int mpc_dma_alloc_chan_resources(struct dma_chan *chan)
500 {
501 struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
502 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
503 struct mpc_dma_desc *mdesc;
504 struct mpc_dma_tcd *tcd;
505 dma_addr_t tcd_paddr;
506 unsigned long flags;
507 LIST_HEAD(descs);
508 int i;
509
510 /* Alloc DMA memory for Transfer Control Descriptors */
511 tcd = dma_alloc_coherent(mdma->dma.dev,
512 MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
513 &tcd_paddr, GFP_KERNEL);
514 if (!tcd)
515 return -ENOMEM;
516
517 /* Alloc descriptors for this channel */
518 for (i = 0; i < MPC_DMA_DESCRIPTORS; i++) {
519 mdesc = kzalloc(sizeof(struct mpc_dma_desc), GFP_KERNEL);
520 if (!mdesc) {
521 dev_notice(mdma->dma.dev, "Memory allocation error. "
522 "Allocated only %u descriptors\n", i);
523 break;
524 }
525
526 dma_async_tx_descriptor_init(&mdesc->desc, chan);
527 mdesc->desc.flags = DMA_CTRL_ACK;
528 mdesc->desc.tx_submit = mpc_dma_tx_submit;
529
530 mdesc->tcd = &tcd[i];
531 mdesc->tcd_paddr = tcd_paddr + (i * sizeof(struct mpc_dma_tcd));
532
533 list_add_tail(&mdesc->node, &descs);
534 }
535
536 /* Return error only if no descriptors were allocated */
537 if (i == 0) {
538 dma_free_coherent(mdma->dma.dev,
539 MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
540 tcd, tcd_paddr);
541 return -ENOMEM;
542 }
543
544 spin_lock_irqsave(&mchan->lock, flags);
545 mchan->tcd = tcd;
546 mchan->tcd_paddr = tcd_paddr;
547 list_splice_tail_init(&descs, &mchan->free);
548 spin_unlock_irqrestore(&mchan->lock, flags);
549
550 /* Enable Error Interrupt */
551 out_8(&mdma->regs->dmaseei, chan->chan_id);
552
553 return 0;
554 }
555
556 /* Free channel resources */
557 static void mpc_dma_free_chan_resources(struct dma_chan *chan)
558 {
559 struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
560 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
561 struct mpc_dma_desc *mdesc, *tmp;
562 struct mpc_dma_tcd *tcd;
563 dma_addr_t tcd_paddr;
564 unsigned long flags;
565 LIST_HEAD(descs);
566
567 spin_lock_irqsave(&mchan->lock, flags);
568
569 /* Channel must be idle */
570 BUG_ON(!list_empty(&mchan->prepared));
571 BUG_ON(!list_empty(&mchan->queued));
572 BUG_ON(!list_empty(&mchan->active));
573 BUG_ON(!list_empty(&mchan->completed));
574
575 /* Move data */
576 list_splice_tail_init(&mchan->free, &descs);
577 tcd = mchan->tcd;
578 tcd_paddr = mchan->tcd_paddr;
579
580 spin_unlock_irqrestore(&mchan->lock, flags);
581
582 /* Free DMA memory used by descriptors */
583 dma_free_coherent(mdma->dma.dev,
584 MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
585 tcd, tcd_paddr);
586
587 /* Free descriptors */
588 list_for_each_entry_safe(mdesc, tmp, &descs, node)
589 kfree(mdesc);
590
591 /* Disable Error Interrupt */
592 out_8(&mdma->regs->dmaceei, chan->chan_id);
593 }
594
595 /* Send all pending descriptor to hardware */
596 static void mpc_dma_issue_pending(struct dma_chan *chan)
597 {
598 /*
599 * We are posting descriptors to the hardware as soon as
600 * they are ready, so this function does nothing.
601 */
602 }
603
604 /* Check request completion status */
605 static enum dma_status
606 mpc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
607 struct dma_tx_state *txstate)
608 {
609 return dma_cookie_status(chan, cookie, txstate);
610 }
611
612 /* Prepare descriptor for memory to memory copy */
613 static struct dma_async_tx_descriptor *
614 mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
615 size_t len, unsigned long flags)
616 {
617 struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
618 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
619 struct mpc_dma_desc *mdesc = NULL;
620 struct mpc_dma_tcd *tcd;
621 unsigned long iflags;
622
623 /* Get free descriptor */
624 spin_lock_irqsave(&mchan->lock, iflags);
625 if (!list_empty(&mchan->free)) {
626 mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
627 node);
628 list_del(&mdesc->node);
629 }
630 spin_unlock_irqrestore(&mchan->lock, iflags);
631
632 if (!mdesc) {
633 /* try to free completed descriptors */
634 mpc_dma_process_completed(mdma);
635 return NULL;
636 }
637
638 mdesc->error = 0;
639 mdesc->will_access_peripheral = 0;
640 tcd = mdesc->tcd;
641
642 /* Prepare Transfer Control Descriptor for this transaction */
643 memset(tcd, 0, sizeof(struct mpc_dma_tcd));
644
645 if (IS_ALIGNED(src | dst | len, 32)) {
646 tcd->ssize = MPC_DMA_TSIZE_32;
647 tcd->dsize = MPC_DMA_TSIZE_32;
648 tcd->soff = 32;
649 tcd->doff = 32;
650 } else if (!mdma->is_mpc8308 && IS_ALIGNED(src | dst | len, 16)) {
651 /* MPC8308 doesn't support 16 byte transfers */
652 tcd->ssize = MPC_DMA_TSIZE_16;
653 tcd->dsize = MPC_DMA_TSIZE_16;
654 tcd->soff = 16;
655 tcd->doff = 16;
656 } else if (IS_ALIGNED(src | dst | len, 4)) {
657 tcd->ssize = MPC_DMA_TSIZE_4;
658 tcd->dsize = MPC_DMA_TSIZE_4;
659 tcd->soff = 4;
660 tcd->doff = 4;
661 } else if (IS_ALIGNED(src | dst | len, 2)) {
662 tcd->ssize = MPC_DMA_TSIZE_2;
663 tcd->dsize = MPC_DMA_TSIZE_2;
664 tcd->soff = 2;
665 tcd->doff = 2;
666 } else {
667 tcd->ssize = MPC_DMA_TSIZE_1;
668 tcd->dsize = MPC_DMA_TSIZE_1;
669 tcd->soff = 1;
670 tcd->doff = 1;
671 }
672
673 tcd->saddr = src;
674 tcd->daddr = dst;
675 tcd->nbytes = len;
676 tcd->biter = 1;
677 tcd->citer = 1;
678
679 /* Place descriptor in prepared list */
680 spin_lock_irqsave(&mchan->lock, iflags);
681 list_add_tail(&mdesc->node, &mchan->prepared);
682 spin_unlock_irqrestore(&mchan->lock, iflags);
683
684 return &mdesc->desc;
685 }
686
687 static struct dma_async_tx_descriptor *
688 mpc_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
689 unsigned int sg_len, enum dma_transfer_direction direction,
690 unsigned long flags, void *context)
691 {
692 struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
693 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
694 struct mpc_dma_desc *mdesc = NULL;
695 dma_addr_t per_paddr;
696 u32 tcd_nunits;
697 struct mpc_dma_tcd *tcd;
698 unsigned long iflags;
699 struct scatterlist *sg;
700 size_t len;
701 int iter, i;
702
703 /* Currently there is no proper support for scatter/gather */
704 if (sg_len != 1)
705 return NULL;
706
707 if (!is_slave_direction(direction))
708 return NULL;
709
710 for_each_sg(sgl, sg, sg_len, i) {
711 spin_lock_irqsave(&mchan->lock, iflags);
712
713 mdesc = list_first_entry(&mchan->free,
714 struct mpc_dma_desc, node);
715 if (!mdesc) {
716 spin_unlock_irqrestore(&mchan->lock, iflags);
717 /* Try to free completed descriptors */
718 mpc_dma_process_completed(mdma);
719 return NULL;
720 }
721
722 list_del(&mdesc->node);
723
724 if (direction == DMA_DEV_TO_MEM) {
725 per_paddr = mchan->src_per_paddr;
726 tcd_nunits = mchan->src_tcd_nunits;
727 } else {
728 per_paddr = mchan->dst_per_paddr;
729 tcd_nunits = mchan->dst_tcd_nunits;
730 }
731
732 spin_unlock_irqrestore(&mchan->lock, iflags);
733
734 if (per_paddr == 0 || tcd_nunits == 0)
735 goto err_prep;
736
737 mdesc->error = 0;
738 mdesc->will_access_peripheral = 1;
739
740 /* Prepare Transfer Control Descriptor for this transaction */
741 tcd = mdesc->tcd;
742
743 memset(tcd, 0, sizeof(struct mpc_dma_tcd));
744
745 if (!IS_ALIGNED(sg_dma_address(sg), 4))
746 goto err_prep;
747
748 if (direction == DMA_DEV_TO_MEM) {
749 tcd->saddr = per_paddr;
750 tcd->daddr = sg_dma_address(sg);
751 tcd->soff = 0;
752 tcd->doff = 4;
753 } else {
754 tcd->saddr = sg_dma_address(sg);
755 tcd->daddr = per_paddr;
756 tcd->soff = 4;
757 tcd->doff = 0;
758 }
759
760 tcd->ssize = MPC_DMA_TSIZE_4;
761 tcd->dsize = MPC_DMA_TSIZE_4;
762
763 len = sg_dma_len(sg);
764 tcd->nbytes = tcd_nunits * 4;
765 if (!IS_ALIGNED(len, tcd->nbytes))
766 goto err_prep;
767
768 iter = len / tcd->nbytes;
769 if (iter >= 1 << 15) {
770 /* len is too big */
771 goto err_prep;
772 }
773 /* citer_linkch contains the high bits of iter */
774 tcd->biter = iter & 0x1ff;
775 tcd->biter_linkch = iter >> 9;
776 tcd->citer = tcd->biter;
777 tcd->citer_linkch = tcd->biter_linkch;
778
779 tcd->e_sg = 0;
780 tcd->d_req = 1;
781
782 /* Place descriptor in prepared list */
783 spin_lock_irqsave(&mchan->lock, iflags);
784 list_add_tail(&mdesc->node, &mchan->prepared);
785 spin_unlock_irqrestore(&mchan->lock, iflags);
786 }
787
788 return &mdesc->desc;
789
790 err_prep:
791 /* Put the descriptor back */
792 spin_lock_irqsave(&mchan->lock, iflags);
793 list_add_tail(&mdesc->node, &mchan->free);
794 spin_unlock_irqrestore(&mchan->lock, iflags);
795
796 return NULL;
797 }
798
799 static int mpc_dma_device_config(struct dma_chan *chan,
800 struct dma_slave_config *cfg)
801 {
802 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
803 unsigned long flags;
804
805 /*
806 * Software constraints:
807 * - only transfers between a peripheral device and
808 * memory are supported;
809 * - only peripheral devices with 4-byte FIFO access register
810 * are supported;
811 * - minimal transfer chunk is 4 bytes and consequently
812 * source and destination addresses must be 4-byte aligned
813 * and transfer size must be aligned on (4 * maxburst)
814 * boundary;
815 * - during the transfer RAM address is being incremented by
816 * the size of minimal transfer chunk;
817 * - peripheral port's address is constant during the transfer.
818 */
819
820 if (cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES ||
821 cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES ||
822 !IS_ALIGNED(cfg->src_addr, 4) ||
823 !IS_ALIGNED(cfg->dst_addr, 4)) {
824 return -EINVAL;
825 }
826
827 spin_lock_irqsave(&mchan->lock, flags);
828
829 mchan->src_per_paddr = cfg->src_addr;
830 mchan->src_tcd_nunits = cfg->src_maxburst;
831 mchan->dst_per_paddr = cfg->dst_addr;
832 mchan->dst_tcd_nunits = cfg->dst_maxburst;
833
834 /* Apply defaults */
835 if (mchan->src_tcd_nunits == 0)
836 mchan->src_tcd_nunits = 1;
837 if (mchan->dst_tcd_nunits == 0)
838 mchan->dst_tcd_nunits = 1;
839
840 spin_unlock_irqrestore(&mchan->lock, flags);
841
842 return 0;
843 }
844
845 static int mpc_dma_device_terminate_all(struct dma_chan *chan)
846 {
847 struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
848 struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
849 unsigned long flags;
850
851 /* Disable channel requests */
852 spin_lock_irqsave(&mchan->lock, flags);
853
854 out_8(&mdma->regs->dmacerq, chan->chan_id);
855 list_splice_tail_init(&mchan->prepared, &mchan->free);
856 list_splice_tail_init(&mchan->queued, &mchan->free);
857 list_splice_tail_init(&mchan->active, &mchan->free);
858
859 spin_unlock_irqrestore(&mchan->lock, flags);
860
861 return 0;
862 }
863
864 static int mpc_dma_probe(struct platform_device *op)
865 {
866 struct device_node *dn = op->dev.of_node;
867 struct device *dev = &op->dev;
868 struct dma_device *dma;
869 struct mpc_dma *mdma;
870 struct mpc_dma_chan *mchan;
871 struct resource res;
872 ulong regs_start, regs_size;
873 int retval, i;
874 u8 chancnt;
875
876 mdma = devm_kzalloc(dev, sizeof(struct mpc_dma), GFP_KERNEL);
877 if (!mdma) {
878 dev_err(dev, "Memory exhausted!\n");
879 retval = -ENOMEM;
880 goto err;
881 }
882
883 mdma->irq = irq_of_parse_and_map(dn, 0);
884 if (mdma->irq == NO_IRQ) {
885 dev_err(dev, "Error mapping IRQ!\n");
886 retval = -EINVAL;
887 goto err;
888 }
889
890 if (of_device_is_compatible(dn, "fsl,mpc8308-dma")) {
891 mdma->is_mpc8308 = 1;
892 mdma->irq2 = irq_of_parse_and_map(dn, 1);
893 if (mdma->irq2 == NO_IRQ) {
894 dev_err(dev, "Error mapping IRQ!\n");
895 retval = -EINVAL;
896 goto err_dispose1;
897 }
898 }
899
900 retval = of_address_to_resource(dn, 0, &res);
901 if (retval) {
902 dev_err(dev, "Error parsing memory region!\n");
903 goto err_dispose2;
904 }
905
906 regs_start = res.start;
907 regs_size = resource_size(&res);
908
909 if (!devm_request_mem_region(dev, regs_start, regs_size, DRV_NAME)) {
910 dev_err(dev, "Error requesting memory region!\n");
911 retval = -EBUSY;
912 goto err_dispose2;
913 }
914
915 mdma->regs = devm_ioremap(dev, regs_start, regs_size);
916 if (!mdma->regs) {
917 dev_err(dev, "Error mapping memory region!\n");
918 retval = -ENOMEM;
919 goto err_dispose2;
920 }
921
922 mdma->tcd = (struct mpc_dma_tcd *)((u8 *)(mdma->regs)
923 + MPC_DMA_TCD_OFFSET);
924
925 retval = request_irq(mdma->irq, &mpc_dma_irq, 0, DRV_NAME, mdma);
926 if (retval) {
927 dev_err(dev, "Error requesting IRQ!\n");
928 retval = -EINVAL;
929 goto err_dispose2;
930 }
931
932 if (mdma->is_mpc8308) {
933 retval = request_irq(mdma->irq2, &mpc_dma_irq, 0,
934 DRV_NAME, mdma);
935 if (retval) {
936 dev_err(dev, "Error requesting IRQ2!\n");
937 retval = -EINVAL;
938 goto err_free1;
939 }
940 }
941
942 spin_lock_init(&mdma->error_status_lock);
943
944 dma = &mdma->dma;
945 dma->dev = dev;
946 dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources;
947 dma->device_free_chan_resources = mpc_dma_free_chan_resources;
948 dma->device_issue_pending = mpc_dma_issue_pending;
949 dma->device_tx_status = mpc_dma_tx_status;
950 dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy;
951 dma->device_prep_slave_sg = mpc_dma_prep_slave_sg;
952 dma->device_config = mpc_dma_device_config;
953 dma->device_terminate_all = mpc_dma_device_terminate_all;
954
955 INIT_LIST_HEAD(&dma->channels);
956 dma_cap_set(DMA_MEMCPY, dma->cap_mask);
957 dma_cap_set(DMA_SLAVE, dma->cap_mask);
958
959 if (mdma->is_mpc8308)
960 chancnt = MPC8308_DMACHAN_MAX;
961 else
962 chancnt = MPC512x_DMACHAN_MAX;
963
964 for (i = 0; i < chancnt; i++) {
965 mchan = &mdma->channels[i];
966
967 mchan->chan.device = dma;
968 dma_cookie_init(&mchan->chan);
969
970 INIT_LIST_HEAD(&mchan->free);
971 INIT_LIST_HEAD(&mchan->prepared);
972 INIT_LIST_HEAD(&mchan->queued);
973 INIT_LIST_HEAD(&mchan->active);
974 INIT_LIST_HEAD(&mchan->completed);
975
976 spin_lock_init(&mchan->lock);
977 list_add_tail(&mchan->chan.device_node, &dma->channels);
978 }
979
980 tasklet_init(&mdma->tasklet, mpc_dma_tasklet, (unsigned long)mdma);
981
982 /*
983 * Configure DMA Engine:
984 * - Dynamic clock,
985 * - Round-robin group arbitration,
986 * - Round-robin channel arbitration.
987 */
988 if (mdma->is_mpc8308) {
989 /* MPC8308 has 16 channels and lacks some registers */
990 out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
991
992 /* enable snooping */
993 out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
994 /* Disable error interrupts */
995 out_be32(&mdma->regs->dmaeeil, 0);
996
997 /* Clear interrupts status */
998 out_be32(&mdma->regs->dmaintl, 0xFFFF);
999 out_be32(&mdma->regs->dmaerrl, 0xFFFF);
1000 } else {
1001 out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG |
1002 MPC_DMA_DMACR_ERGA | MPC_DMA_DMACR_ERCA);
1003
1004 /* Disable hardware DMA requests */
1005 out_be32(&mdma->regs->dmaerqh, 0);
1006 out_be32(&mdma->regs->dmaerql, 0);
1007
1008 /* Disable error interrupts */
1009 out_be32(&mdma->regs->dmaeeih, 0);
1010 out_be32(&mdma->regs->dmaeeil, 0);
1011
1012 /* Clear interrupts status */
1013 out_be32(&mdma->regs->dmainth, 0xFFFFFFFF);
1014 out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF);
1015 out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF);
1016 out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF);
1017
1018 /* Route interrupts to IPIC */
1019 out_be32(&mdma->regs->dmaihsa, 0);
1020 out_be32(&mdma->regs->dmailsa, 0);
1021 }
1022
1023 /* Register DMA engine */
1024 dev_set_drvdata(dev, mdma);
1025 retval = dma_async_device_register(dma);
1026 if (retval)
1027 goto err_free2;
1028
1029 /* Register with OF helpers for DMA lookups (nonfatal) */
1030 if (dev->of_node) {
1031 retval = of_dma_controller_register(dev->of_node,
1032 of_dma_xlate_by_chan_id, mdma);
1033 if (retval)
1034 dev_warn(dev, "Could not register for OF lookup\n");
1035 }
1036
1037 return 0;
1038
1039 err_free2:
1040 if (mdma->is_mpc8308)
1041 free_irq(mdma->irq2, mdma);
1042 err_free1:
1043 free_irq(mdma->irq, mdma);
1044 err_dispose2:
1045 if (mdma->is_mpc8308)
1046 irq_dispose_mapping(mdma->irq2);
1047 err_dispose1:
1048 irq_dispose_mapping(mdma->irq);
1049 err:
1050 return retval;
1051 }
1052
1053 static int mpc_dma_remove(struct platform_device *op)
1054 {
1055 struct device *dev = &op->dev;
1056 struct mpc_dma *mdma = dev_get_drvdata(dev);
1057
1058 if (dev->of_node)
1059 of_dma_controller_free(dev->of_node);
1060 dma_async_device_unregister(&mdma->dma);
1061 if (mdma->is_mpc8308) {
1062 free_irq(mdma->irq2, mdma);
1063 irq_dispose_mapping(mdma->irq2);
1064 }
1065 free_irq(mdma->irq, mdma);
1066 irq_dispose_mapping(mdma->irq);
1067
1068 return 0;
1069 }
1070
1071 static const struct of_device_id mpc_dma_match[] = {
1072 { .compatible = "fsl,mpc5121-dma", },
1073 { .compatible = "fsl,mpc8308-dma", },
1074 {},
1075 };
1076 MODULE_DEVICE_TABLE(of, mpc_dma_match);
1077
1078 static struct platform_driver mpc_dma_driver = {
1079 .probe = mpc_dma_probe,
1080 .remove = mpc_dma_remove,
1081 .driver = {
1082 .name = DRV_NAME,
1083 .of_match_table = mpc_dma_match,
1084 },
1085 };
1086
1087 module_platform_driver(mpc_dma_driver);
1088
1089 MODULE_LICENSE("GPL");
1090 MODULE_AUTHOR("Piotr Ziecik <kosmo@semihalf.com>");
Linux kernel - Deliverables
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