1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2012 Marvell International Ltd.
4 */
5
6 #include <linux/err.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/interrupt.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/slab.h>
13 #include <linux/dmaengine.h>
14 #include <linux/platform_device.h>
15 #include <linux/device.h>
16 #include <linux/platform_data/mmp_dma.h>
17 #include <linux/dmapool.h>
18 #include <linux/of_device.h>
19 #include <linux/of_dma.h>
20 #include <linux/of.h>
21
22 #include "dmaengine.h"
23
24 #define DCSR 0x0000
25 #define DALGN 0x00a0
26 #define DINT 0x00f0
27 #define DDADR 0x0200
28 #define DSADR(n) (0x0204 + ((n) << 4))
29 #define DTADR(n) (0x0208 + ((n) << 4))
30 #define DCMD 0x020c
31
32 #define DCSR_RUN BIT(31) /* Run Bit (read / write) */
33 #define DCSR_NODESC BIT(30) /* No-Descriptor Fetch (read / write) */
34 #define DCSR_STOPIRQEN BIT(29) /* Stop Interrupt Enable (read / write) */
35 #define DCSR_REQPEND BIT(8) /* Request Pending (read-only) */
36 #define DCSR_STOPSTATE BIT(3) /* Stop State (read-only) */
37 #define DCSR_ENDINTR BIT(2) /* End Interrupt (read / write) */
38 #define DCSR_STARTINTR BIT(1) /* Start Interrupt (read / write) */
39 #define DCSR_BUSERR BIT(0) /* Bus Error Interrupt (read / write) */
40
41 #define DCSR_EORIRQEN BIT(28) /* End of Receive Interrupt Enable (R/W) */
42 #define DCSR_EORJMPEN BIT(27) /* Jump to next descriptor on EOR */
43 #define DCSR_EORSTOPEN BIT(26) /* STOP on an EOR */
44 #define DCSR_SETCMPST BIT(25) /* Set Descriptor Compare Status */
45 #define DCSR_CLRCMPST BIT(24) /* Clear Descriptor Compare Status */
46 #define DCSR_CMPST BIT(10) /* The Descriptor Compare Status */
47 #define DCSR_EORINTR BIT(9) /* The end of Receive */
48
49 #define DRCMR(n) ((((n) < 64) ? 0x0100 : 0x1100) + (((n) & 0x3f) << 2))
50 #define DRCMR_MAPVLD BIT(7) /* Map Valid (read / write) */
51 #define DRCMR_CHLNUM 0x1f /* mask for Channel Number (read / write) */
52
53 #define DDADR_DESCADDR 0xfffffff0 /* Address of next descriptor (mask) */
54 #define DDADR_STOP BIT(0) /* Stop (read / write) */
55
56 #define DCMD_INCSRCADDR BIT(31) /* Source Address Increment Setting. */
57 #define DCMD_INCTRGADDR BIT(30) /* Target Address Increment Setting. */
58 #define DCMD_FLOWSRC BIT(29) /* Flow Control by the source. */
59 #define DCMD_FLOWTRG BIT(28) /* Flow Control by the target. */
60 #define DCMD_STARTIRQEN BIT(22) /* Start Interrupt Enable */
61 #define DCMD_ENDIRQEN BIT(21) /* End Interrupt Enable */
62 #define DCMD_ENDIAN BIT(18) /* Device Endian-ness. */
63 #define DCMD_BURST8 (1 << 16) /* 8 byte burst */
64 #define DCMD_BURST16 (2 << 16) /* 16 byte burst */
65 #define DCMD_BURST32 (3 << 16) /* 32 byte burst */
66 #define DCMD_WIDTH1 (1 << 14) /* 1 byte width */
67 #define DCMD_WIDTH2 (2 << 14) /* 2 byte width (HalfWord) */
68 #define DCMD_WIDTH4 (3 << 14) /* 4 byte width (Word) */
69 #define DCMD_LENGTH 0x01fff /* length mask (max = 8K - 1) */
70
71 #define PDMA_MAX_DESC_BYTES DCMD_LENGTH
72
73 struct mmp_pdma_desc_hw {
74 u32 ddadr; /* Points to the next descriptor + flags */
75 u32 dsadr; /* DSADR value for the current transfer */
76 u32 dtadr; /* DTADR value for the current transfer */
77 u32 dcmd; /* DCMD value for the current transfer */
78 } __aligned(32);
79
80 struct mmp_pdma_desc_sw {
81 struct mmp_pdma_desc_hw desc;
82 struct list_head node;
83 struct list_head tx_list;
84 struct dma_async_tx_descriptor async_tx;
85 };
86
87 struct mmp_pdma_phy;
88
89 struct mmp_pdma_chan {
90 struct device *dev;
91 struct dma_chan chan;
92 struct dma_async_tx_descriptor desc;
93 struct mmp_pdma_phy *phy;
94 enum dma_transfer_direction dir;
95 struct dma_slave_config slave_config;
96
97 struct mmp_pdma_desc_sw *cyclic_first; /* first desc_sw if channel
98 * is in cyclic mode */
99
100 /* channel's basic info */
101 struct tasklet_struct tasklet;
102 u32 dcmd;
103 u32 drcmr;
104 u32 dev_addr;
105
106 /* list for desc */
107 spinlock_t desc_lock; /* Descriptor list lock */
108 struct list_head chain_pending; /* Link descriptors queue for pending */
109 struct list_head chain_running; /* Link descriptors queue for running */
110 bool idle; /* channel statue machine */
111 bool byte_align;
112
113 struct dma_pool *desc_pool; /* Descriptors pool */
114 };
115
116 struct mmp_pdma_phy {
117 int idx;
118 void __iomem *base;
119 struct mmp_pdma_chan *vchan;
120 };
121
122 struct mmp_pdma_device {
123 int dma_channels;
124 void __iomem *base;
125 struct device *dev;
126 struct dma_device device;
127 struct mmp_pdma_phy *phy;
128 spinlock_t phy_lock; /* protect alloc/free phy channels */
129 };
130
131 #define tx_to_mmp_pdma_desc(tx) \
132 container_of(tx, struct mmp_pdma_desc_sw, async_tx)
133 #define to_mmp_pdma_desc(lh) \
134 container_of(lh, struct mmp_pdma_desc_sw, node)
135 #define to_mmp_pdma_chan(dchan) \
136 container_of(dchan, struct mmp_pdma_chan, chan)
137 #define to_mmp_pdma_dev(dmadev) \
138 container_of(dmadev, struct mmp_pdma_device, device)
139
140 static int mmp_pdma_config_write(struct dma_chan *dchan,
141 struct dma_slave_config *cfg,
142 enum dma_transfer_direction direction);
143
set_desc(struct mmp_pdma_phy * phy,dma_addr_t addr)144 static void set_desc(struct mmp_pdma_phy *phy, dma_addr_t addr)
145 {
146 u32 reg = (phy->idx << 4) + DDADR;
147
148 writel(addr, phy->base + reg);
149 }
150
enable_chan(struct mmp_pdma_phy * phy)151 static void enable_chan(struct mmp_pdma_phy *phy)
152 {
153 u32 reg, dalgn;
154
155 if (!phy->vchan)
156 return;
157
158 reg = DRCMR(phy->vchan->drcmr);
159 writel(DRCMR_MAPVLD | phy->idx, phy->base + reg);
160
161 dalgn = readl(phy->base + DALGN);
162 if (phy->vchan->byte_align)
163 dalgn |= 1 << phy->idx;
164 else
165 dalgn &= ~(1 << phy->idx);
166 writel(dalgn, phy->base + DALGN);
167
168 reg = (phy->idx << 2) + DCSR;
169 writel(readl(phy->base + reg) | DCSR_RUN, phy->base + reg);
170 }
171
disable_chan(struct mmp_pdma_phy * phy)172 static void disable_chan(struct mmp_pdma_phy *phy)
173 {
174 u32 reg;
175
176 if (!phy)
177 return;
178
179 reg = (phy->idx << 2) + DCSR;
180 writel(readl(phy->base + reg) & ~DCSR_RUN, phy->base + reg);
181 }
182
clear_chan_irq(struct mmp_pdma_phy * phy)183 static int clear_chan_irq(struct mmp_pdma_phy *phy)
184 {
185 u32 dcsr;
186 u32 dint = readl(phy->base + DINT);
187 u32 reg = (phy->idx << 2) + DCSR;
188
189 if (!(dint & BIT(phy->idx)))
190 return -EAGAIN;
191
192 /* clear irq */
193 dcsr = readl(phy->base + reg);
194 writel(dcsr, phy->base + reg);
195 if ((dcsr & DCSR_BUSERR) && (phy->vchan))
196 dev_warn(phy->vchan->dev, "DCSR_BUSERR\n");
197
198 return 0;
199 }
200
mmp_pdma_chan_handler(int irq,void * dev_id)201 static irqreturn_t mmp_pdma_chan_handler(int irq, void *dev_id)
202 {
203 struct mmp_pdma_phy *phy = dev_id;
204
205 if (clear_chan_irq(phy) != 0)
206 return IRQ_NONE;
207
208 tasklet_schedule(&phy->vchan->tasklet);
209 return IRQ_HANDLED;
210 }
211
mmp_pdma_int_handler(int irq,void * dev_id)212 static irqreturn_t mmp_pdma_int_handler(int irq, void *dev_id)
213 {
214 struct mmp_pdma_device *pdev = dev_id;
215 struct mmp_pdma_phy *phy;
216 u32 dint = readl(pdev->base + DINT);
217 int i, ret;
218 int irq_num = 0;
219
220 while (dint) {
221 i = __ffs(dint);
222 /* only handle interrupts belonging to pdma driver*/
223 if (i >= pdev->dma_channels)
224 break;
225 dint &= (dint - 1);
226 phy = &pdev->phy[i];
227 ret = mmp_pdma_chan_handler(irq, phy);
228 if (ret == IRQ_HANDLED)
229 irq_num++;
230 }
231
232 if (irq_num)
233 return IRQ_HANDLED;
234
235 return IRQ_NONE;
236 }
237
238 /* lookup free phy channel as descending priority */
lookup_phy(struct mmp_pdma_chan * pchan)239 static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
240 {
241 int prio, i;
242 struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
243 struct mmp_pdma_phy *phy, *found = NULL;
244 unsigned long flags;
245
246 /*
247 * dma channel priorities
248 * ch 0 - 3, 16 - 19 <--> (0)
249 * ch 4 - 7, 20 - 23 <--> (1)
250 * ch 8 - 11, 24 - 27 <--> (2)
251 * ch 12 - 15, 28 - 31 <--> (3)
252 */
253
254 spin_lock_irqsave(&pdev->phy_lock, flags);
255 for (prio = 0; prio <= ((pdev->dma_channels - 1) & 0xf) >> 2; prio++) {
256 for (i = 0; i < pdev->dma_channels; i++) {
257 if (prio != (i & 0xf) >> 2)
258 continue;
259 phy = &pdev->phy[i];
260 if (!phy->vchan) {
261 phy->vchan = pchan;
262 found = phy;
263 goto out_unlock;
264 }
265 }
266 }
267
268 out_unlock:
269 spin_unlock_irqrestore(&pdev->phy_lock, flags);
270 return found;
271 }
272
mmp_pdma_free_phy(struct mmp_pdma_chan * pchan)273 static void mmp_pdma_free_phy(struct mmp_pdma_chan *pchan)
274 {
275 struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
276 unsigned long flags;
277 u32 reg;
278
279 if (!pchan->phy)
280 return;
281
282 /* clear the channel mapping in DRCMR */
283 reg = DRCMR(pchan->drcmr);
284 writel(0, pchan->phy->base + reg);
285
286 spin_lock_irqsave(&pdev->phy_lock, flags);
287 pchan->phy->vchan = NULL;
288 pchan->phy = NULL;
289 spin_unlock_irqrestore(&pdev->phy_lock, flags);
290 }
291
292 /*
293 * start_pending_queue - transfer any pending transactions
294 * pending list ==> running list
295 */
start_pending_queue(struct mmp_pdma_chan * chan)296 static void start_pending_queue(struct mmp_pdma_chan *chan)
297 {
298 struct mmp_pdma_desc_sw *desc;
299
300 /* still in running, irq will start the pending list */
301 if (!chan->idle) {
302 dev_dbg(chan->dev, "DMA controller still busy\n");
303 return;
304 }
305
306 if (list_empty(&chan->chain_pending)) {
307 /* chance to re-fetch phy channel with higher prio */
308 mmp_pdma_free_phy(chan);
309 dev_dbg(chan->dev, "no pending list\n");
310 return;
311 }
312
313 if (!chan->phy) {
314 chan->phy = lookup_phy(chan);
315 if (!chan->phy) {
316 dev_dbg(chan->dev, "no free dma channel\n");
317 return;
318 }
319 }
320
321 /*
322 * pending -> running
323 * reintilize pending list
324 */
325 desc = list_first_entry(&chan->chain_pending,
326 struct mmp_pdma_desc_sw, node);
327 list_splice_tail_init(&chan->chain_pending, &chan->chain_running);
328
329 /*
330 * Program the descriptor's address into the DMA controller,
331 * then start the DMA transaction
332 */
333 set_desc(chan->phy, desc->async_tx.phys);
334 enable_chan(chan->phy);
335 chan->idle = false;
336 }
337
338
339 /* desc->tx_list ==> pending list */
mmp_pdma_tx_submit(struct dma_async_tx_descriptor * tx)340 static dma_cookie_t mmp_pdma_tx_submit(struct dma_async_tx_descriptor *tx)
341 {
342 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(tx->chan);
343 struct mmp_pdma_desc_sw *desc = tx_to_mmp_pdma_desc(tx);
344 struct mmp_pdma_desc_sw *child;
345 unsigned long flags;
346 dma_cookie_t cookie = -EBUSY;
347
348 spin_lock_irqsave(&chan->desc_lock, flags);
349
350 list_for_each_entry(child, &desc->tx_list, node) {
351 cookie = dma_cookie_assign(&child->async_tx);
352 }
353
354 /* softly link to pending list - desc->tx_list ==> pending list */
355 list_splice_tail_init(&desc->tx_list, &chan->chain_pending);
356
357 spin_unlock_irqrestore(&chan->desc_lock, flags);
358
359 return cookie;
360 }
361
362 static struct mmp_pdma_desc_sw *
mmp_pdma_alloc_descriptor(struct mmp_pdma_chan * chan)363 mmp_pdma_alloc_descriptor(struct mmp_pdma_chan *chan)
364 {
365 struct mmp_pdma_desc_sw *desc;
366 dma_addr_t pdesc;
367
368 desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
369 if (!desc) {
370 dev_err(chan->dev, "out of memory for link descriptor\n");
371 return NULL;
372 }
373
374 INIT_LIST_HEAD(&desc->tx_list);
375 dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan);
376 /* each desc has submit */
377 desc->async_tx.tx_submit = mmp_pdma_tx_submit;
378 desc->async_tx.phys = pdesc;
379
380 return desc;
381 }
382
383 /*
384 * mmp_pdma_alloc_chan_resources - Allocate resources for DMA channel.
385 *
386 * This function will create a dma pool for descriptor allocation.
387 * Request irq only when channel is requested
388 * Return - The number of allocated descriptors.
389 */
390
mmp_pdma_alloc_chan_resources(struct dma_chan * dchan)391 static int mmp_pdma_alloc_chan_resources(struct dma_chan *dchan)
392 {
393 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
394
395 if (chan->desc_pool)
396 return 1;
397
398 chan->desc_pool = dma_pool_create(dev_name(&dchan->dev->device),
399 chan->dev,
400 sizeof(struct mmp_pdma_desc_sw),
401 __alignof__(struct mmp_pdma_desc_sw),
402 0);
403 if (!chan->desc_pool) {
404 dev_err(chan->dev, "unable to allocate descriptor pool\n");
405 return -ENOMEM;
406 }
407
408 mmp_pdma_free_phy(chan);
409 chan->idle = true;
410 chan->dev_addr = 0;
411 return 1;
412 }
413
mmp_pdma_free_desc_list(struct mmp_pdma_chan * chan,struct list_head * list)414 static void mmp_pdma_free_desc_list(struct mmp_pdma_chan *chan,
415 struct list_head *list)
416 {
417 struct mmp_pdma_desc_sw *desc, *_desc;
418
419 list_for_each_entry_safe(desc, _desc, list, node) {
420 list_del(&desc->node);
421 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
422 }
423 }
424
mmp_pdma_free_chan_resources(struct dma_chan * dchan)425 static void mmp_pdma_free_chan_resources(struct dma_chan *dchan)
426 {
427 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
428 unsigned long flags;
429
430 spin_lock_irqsave(&chan->desc_lock, flags);
431 mmp_pdma_free_desc_list(chan, &chan->chain_pending);
432 mmp_pdma_free_desc_list(chan, &chan->chain_running);
433 spin_unlock_irqrestore(&chan->desc_lock, flags);
434
435 dma_pool_destroy(chan->desc_pool);
436 chan->desc_pool = NULL;
437 chan->idle = true;
438 chan->dev_addr = 0;
439 mmp_pdma_free_phy(chan);
440 return;
441 }
442
443 static struct dma_async_tx_descriptor *
mmp_pdma_prep_memcpy(struct dma_chan * dchan,dma_addr_t dma_dst,dma_addr_t dma_src,size_t len,unsigned long flags)444 mmp_pdma_prep_memcpy(struct dma_chan *dchan,
445 dma_addr_t dma_dst, dma_addr_t dma_src,
446 size_t len, unsigned long flags)
447 {
448 struct mmp_pdma_chan *chan;
449 struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
450 size_t copy = 0;
451
452 if (!dchan)
453 return NULL;
454
455 if (!len)
456 return NULL;
457
458 chan = to_mmp_pdma_chan(dchan);
459 chan->byte_align = false;
460
461 if (!chan->dir) {
462 chan->dir = DMA_MEM_TO_MEM;
463 chan->dcmd = DCMD_INCTRGADDR | DCMD_INCSRCADDR;
464 chan->dcmd |= DCMD_BURST32;
465 }
466
467 do {
468 /* Allocate the link descriptor from DMA pool */
469 new = mmp_pdma_alloc_descriptor(chan);
470 if (!new) {
471 dev_err(chan->dev, "no memory for desc\n");
472 goto fail;
473 }
474
475 copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
476 if (dma_src & 0x7 || dma_dst & 0x7)
477 chan->byte_align = true;
478
479 new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & copy);
480 new->desc.dsadr = dma_src;
481 new->desc.dtadr = dma_dst;
482
483 if (!first)
484 first = new;
485 else
486 prev->desc.ddadr = new->async_tx.phys;
487
488 new->async_tx.cookie = 0;
489 async_tx_ack(&new->async_tx);
490
491 prev = new;
492 len -= copy;
493
494 if (chan->dir == DMA_MEM_TO_DEV) {
495 dma_src += copy;
496 } else if (chan->dir == DMA_DEV_TO_MEM) {
497 dma_dst += copy;
498 } else if (chan->dir == DMA_MEM_TO_MEM) {
499 dma_src += copy;
500 dma_dst += copy;
501 }
502
503 /* Insert the link descriptor to the LD ring */
504 list_add_tail(&new->node, &first->tx_list);
505 } while (len);
506
507 first->async_tx.flags = flags; /* client is in control of this ack */
508 first->async_tx.cookie = -EBUSY;
509
510 /* last desc and fire IRQ */
511 new->desc.ddadr = DDADR_STOP;
512 new->desc.dcmd |= DCMD_ENDIRQEN;
513
514 chan->cyclic_first = NULL;
515
516 return &first->async_tx;
517
518 fail:
519 if (first)
520 mmp_pdma_free_desc_list(chan, &first->tx_list);
521 return NULL;
522 }
523
524 static struct dma_async_tx_descriptor *
mmp_pdma_prep_slave_sg(struct dma_chan * dchan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction dir,unsigned long flags,void * context)525 mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
526 unsigned int sg_len, enum dma_transfer_direction dir,
527 unsigned long flags, void *context)
528 {
529 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
530 struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new = NULL;
531 size_t len, avail;
532 struct scatterlist *sg;
533 dma_addr_t addr;
534 int i;
535
536 if ((sgl == NULL) || (sg_len == 0))
537 return NULL;
538
539 chan->byte_align = false;
540
541 mmp_pdma_config_write(dchan, &chan->slave_config, dir);
542
543 for_each_sg(sgl, sg, sg_len, i) {
544 addr = sg_dma_address(sg);
545 avail = sg_dma_len(sgl);
546
547 do {
548 len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
549 if (addr & 0x7)
550 chan->byte_align = true;
551
552 /* allocate and populate the descriptor */
553 new = mmp_pdma_alloc_descriptor(chan);
554 if (!new) {
555 dev_err(chan->dev, "no memory for desc\n");
556 goto fail;
557 }
558
559 new->desc.dcmd = chan->dcmd | (DCMD_LENGTH & len);
560 if (dir == DMA_MEM_TO_DEV) {
561 new->desc.dsadr = addr;
562 new->desc.dtadr = chan->dev_addr;
563 } else {
564 new->desc.dsadr = chan->dev_addr;
565 new->desc.dtadr = addr;
566 }
567
568 if (!first)
569 first = new;
570 else
571 prev->desc.ddadr = new->async_tx.phys;
572
573 new->async_tx.cookie = 0;
574 async_tx_ack(&new->async_tx);
575 prev = new;
576
577 /* Insert the link descriptor to the LD ring */
578 list_add_tail(&new->node, &first->tx_list);
579
580 /* update metadata */
581 addr += len;
582 avail -= len;
583 } while (avail);
584 }
585
586 first->async_tx.cookie = -EBUSY;
587 first->async_tx.flags = flags;
588
589 /* last desc and fire IRQ */
590 new->desc.ddadr = DDADR_STOP;
591 new->desc.dcmd |= DCMD_ENDIRQEN;
592
593 chan->dir = dir;
594 chan->cyclic_first = NULL;
595
596 return &first->async_tx;
597
598 fail:
599 if (first)
600 mmp_pdma_free_desc_list(chan, &first->tx_list);
601 return NULL;
602 }
603
604 static struct dma_async_tx_descriptor *
mmp_pdma_prep_dma_cyclic(struct dma_chan * dchan,dma_addr_t buf_addr,size_t len,size_t period_len,enum dma_transfer_direction direction,unsigned long flags)605 mmp_pdma_prep_dma_cyclic(struct dma_chan *dchan,
606 dma_addr_t buf_addr, size_t len, size_t period_len,
607 enum dma_transfer_direction direction,
608 unsigned long flags)
609 {
610 struct mmp_pdma_chan *chan;
611 struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
612 dma_addr_t dma_src, dma_dst;
613
614 if (!dchan || !len || !period_len)
615 return NULL;
616
617 /* the buffer length must be a multiple of period_len */
618 if (len % period_len != 0)
619 return NULL;
620
621 if (period_len > PDMA_MAX_DESC_BYTES)
622 return NULL;
623
624 chan = to_mmp_pdma_chan(dchan);
625 mmp_pdma_config_write(dchan, &chan->slave_config, direction);
626
627 switch (direction) {
628 case DMA_MEM_TO_DEV:
629 dma_src = buf_addr;
630 dma_dst = chan->dev_addr;
631 break;
632 case DMA_DEV_TO_MEM:
633 dma_dst = buf_addr;
634 dma_src = chan->dev_addr;
635 break;
636 default:
637 dev_err(chan->dev, "Unsupported direction for cyclic DMA\n");
638 return NULL;
639 }
640
641 chan->dir = direction;
642
643 do {
644 /* Allocate the link descriptor from DMA pool */
645 new = mmp_pdma_alloc_descriptor(chan);
646 if (!new) {
647 dev_err(chan->dev, "no memory for desc\n");
648 goto fail;
649 }
650
651 new->desc.dcmd = (chan->dcmd | DCMD_ENDIRQEN |
652 (DCMD_LENGTH & period_len));
653 new->desc.dsadr = dma_src;
654 new->desc.dtadr = dma_dst;
655
656 if (!first)
657 first = new;
658 else
659 prev->desc.ddadr = new->async_tx.phys;
660
661 new->async_tx.cookie = 0;
662 async_tx_ack(&new->async_tx);
663
664 prev = new;
665 len -= period_len;
666
667 if (chan->dir == DMA_MEM_TO_DEV)
668 dma_src += period_len;
669 else
670 dma_dst += period_len;
671
672 /* Insert the link descriptor to the LD ring */
673 list_add_tail(&new->node, &first->tx_list);
674 } while (len);
675
676 first->async_tx.flags = flags; /* client is in control of this ack */
677 first->async_tx.cookie = -EBUSY;
678
679 /* make the cyclic link */
680 new->desc.ddadr = first->async_tx.phys;
681 chan->cyclic_first = first;
682
683 return &first->async_tx;
684
685 fail:
686 if (first)
687 mmp_pdma_free_desc_list(chan, &first->tx_list);
688 return NULL;
689 }
690
mmp_pdma_config_write(struct dma_chan * dchan,struct dma_slave_config * cfg,enum dma_transfer_direction direction)691 static int mmp_pdma_config_write(struct dma_chan *dchan,
692 struct dma_slave_config *cfg,
693 enum dma_transfer_direction direction)
694 {
695 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
696 u32 maxburst = 0, addr = 0;
697 enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
698
699 if (!dchan)
700 return -EINVAL;
701
702 if (direction == DMA_DEV_TO_MEM) {
703 chan->dcmd = DCMD_INCTRGADDR | DCMD_FLOWSRC;
704 maxburst = cfg->src_maxburst;
705 width = cfg->src_addr_width;
706 addr = cfg->src_addr;
707 } else if (direction == DMA_MEM_TO_DEV) {
708 chan->dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;
709 maxburst = cfg->dst_maxburst;
710 width = cfg->dst_addr_width;
711 addr = cfg->dst_addr;
712 }
713
714 if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
715 chan->dcmd |= DCMD_WIDTH1;
716 else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
717 chan->dcmd |= DCMD_WIDTH2;
718 else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
719 chan->dcmd |= DCMD_WIDTH4;
720
721 if (maxburst == 8)
722 chan->dcmd |= DCMD_BURST8;
723 else if (maxburst == 16)
724 chan->dcmd |= DCMD_BURST16;
725 else if (maxburst == 32)
726 chan->dcmd |= DCMD_BURST32;
727
728 chan->dir = direction;
729 chan->dev_addr = addr;
730
731 return 0;
732 }
733
mmp_pdma_config(struct dma_chan * dchan,struct dma_slave_config * cfg)734 static int mmp_pdma_config(struct dma_chan *dchan,
735 struct dma_slave_config *cfg)
736 {
737 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
738
739 memcpy(&chan->slave_config, cfg, sizeof(*cfg));
740 return 0;
741 }
742
mmp_pdma_terminate_all(struct dma_chan * dchan)743 static int mmp_pdma_terminate_all(struct dma_chan *dchan)
744 {
745 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
746 unsigned long flags;
747
748 if (!dchan)
749 return -EINVAL;
750
751 disable_chan(chan->phy);
752 mmp_pdma_free_phy(chan);
753 spin_lock_irqsave(&chan->desc_lock, flags);
754 mmp_pdma_free_desc_list(chan, &chan->chain_pending);
755 mmp_pdma_free_desc_list(chan, &chan->chain_running);
756 spin_unlock_irqrestore(&chan->desc_lock, flags);
757 chan->idle = true;
758
759 return 0;
760 }
761
mmp_pdma_residue(struct mmp_pdma_chan * chan,dma_cookie_t cookie)762 static unsigned int mmp_pdma_residue(struct mmp_pdma_chan *chan,
763 dma_cookie_t cookie)
764 {
765 struct mmp_pdma_desc_sw *sw;
766 u32 curr, residue = 0;
767 bool passed = false;
768 bool cyclic = chan->cyclic_first != NULL;
769
770 /*
771 * If the channel does not have a phy pointer anymore, it has already
772 * been completed. Therefore, its residue is 0.
773 */
774 if (!chan->phy)
775 return 0;
776
777 if (chan->dir == DMA_DEV_TO_MEM)
778 curr = readl(chan->phy->base + DTADR(chan->phy->idx));
779 else
780 curr = readl(chan->phy->base + DSADR(chan->phy->idx));
781
782 list_for_each_entry(sw, &chan->chain_running, node) {
783 u32 start, end, len;
784
785 if (chan->dir == DMA_DEV_TO_MEM)
786 start = sw->desc.dtadr;
787 else
788 start = sw->desc.dsadr;
789
790 len = sw->desc.dcmd & DCMD_LENGTH;
791 end = start + len;
792
793 /*
794 * 'passed' will be latched once we found the descriptor which
795 * lies inside the boundaries of the curr pointer. All
796 * descriptors that occur in the list _after_ we found that
797 * partially handled descriptor are still to be processed and
798 * are hence added to the residual bytes counter.
799 */
800
801 if (passed) {
802 residue += len;
803 } else if (curr >= start && curr <= end) {
804 residue += end - curr;
805 passed = true;
806 }
807
808 /*
809 * Descriptors that have the ENDIRQEN bit set mark the end of a
810 * transaction chain, and the cookie assigned with it has been
811 * returned previously from mmp_pdma_tx_submit().
812 *
813 * In case we have multiple transactions in the running chain,
814 * and the cookie does not match the one the user asked us
815 * about, reset the state variables and start over.
816 *
817 * This logic does not apply to cyclic transactions, where all
818 * descriptors have the ENDIRQEN bit set, and for which we
819 * can't have multiple transactions on one channel anyway.
820 */
821 if (cyclic || !(sw->desc.dcmd & DCMD_ENDIRQEN))
822 continue;
823
824 if (sw->async_tx.cookie == cookie) {
825 return residue;
826 } else {
827 residue = 0;
828 passed = false;
829 }
830 }
831
832 /* We should only get here in case of cyclic transactions */
833 return residue;
834 }
835
mmp_pdma_tx_status(struct dma_chan * dchan,dma_cookie_t cookie,struct dma_tx_state * txstate)836 static enum dma_status mmp_pdma_tx_status(struct dma_chan *dchan,
837 dma_cookie_t cookie,
838 struct dma_tx_state *txstate)
839 {
840 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
841 enum dma_status ret;
842
843 ret = dma_cookie_status(dchan, cookie, txstate);
844 if (likely(ret != DMA_ERROR))
845 dma_set_residue(txstate, mmp_pdma_residue(chan, cookie));
846
847 return ret;
848 }
849
850 /*
851 * mmp_pdma_issue_pending - Issue the DMA start command
852 * pending list ==> running list
853 */
mmp_pdma_issue_pending(struct dma_chan * dchan)854 static void mmp_pdma_issue_pending(struct dma_chan *dchan)
855 {
856 struct mmp_pdma_chan *chan = to_mmp_pdma_chan(dchan);
857 unsigned long flags;
858
859 spin_lock_irqsave(&chan->desc_lock, flags);
860 start_pending_queue(chan);
861 spin_unlock_irqrestore(&chan->desc_lock, flags);
862 }
863
864 /*
865 * dma_do_tasklet
866 * Do call back
867 * Start pending list
868 */
dma_do_tasklet(struct tasklet_struct * t)869 static void dma_do_tasklet(struct tasklet_struct *t)
870 {
871 struct mmp_pdma_chan *chan = from_tasklet(chan, t, tasklet);
872 struct mmp_pdma_desc_sw *desc, *_desc;
873 LIST_HEAD(chain_cleanup);
874 unsigned long flags;
875 struct dmaengine_desc_callback cb;
876
877 if (chan->cyclic_first) {
878 spin_lock_irqsave(&chan->desc_lock, flags);
879 desc = chan->cyclic_first;
880 dmaengine_desc_get_callback(&desc->async_tx, &cb);
881 spin_unlock_irqrestore(&chan->desc_lock, flags);
882
883 dmaengine_desc_callback_invoke(&cb, NULL);
884
885 return;
886 }
887
888 /* submit pending list; callback for each desc; free desc */
889 spin_lock_irqsave(&chan->desc_lock, flags);
890
891 list_for_each_entry_safe(desc, _desc, &chan->chain_running, node) {
892 /*
893 * move the descriptors to a temporary list so we can drop
894 * the lock during the entire cleanup operation
895 */
896 list_move(&desc->node, &chain_cleanup);
897
898 /*
899 * Look for the first list entry which has the ENDIRQEN flag
900 * set. That is the descriptor we got an interrupt for, so
901 * complete that transaction and its cookie.
902 */
903 if (desc->desc.dcmd & DCMD_ENDIRQEN) {
904 dma_cookie_t cookie = desc->async_tx.cookie;
905 dma_cookie_complete(&desc->async_tx);
906 dev_dbg(chan->dev, "completed_cookie=%d\n", cookie);
907 break;
908 }
909 }
910
911 /*
912 * The hardware is idle and ready for more when the
913 * chain_running list is empty.
914 */
915 chan->idle = list_empty(&chan->chain_running);
916
917 /* Start any pending transactions automatically */
918 start_pending_queue(chan);
919 spin_unlock_irqrestore(&chan->desc_lock, flags);
920
921 /* Run the callback for each descriptor, in order */
922 list_for_each_entry_safe(desc, _desc, &chain_cleanup, node) {
923 struct dma_async_tx_descriptor *txd = &desc->async_tx;
924
925 /* Remove from the list of transactions */
926 list_del(&desc->node);
927 /* Run the link descriptor callback function */
928 dmaengine_desc_get_callback(txd, &cb);
929 dmaengine_desc_callback_invoke(&cb, NULL);
930
931 dma_pool_free(chan->desc_pool, desc, txd->phys);
932 }
933 }
934
mmp_pdma_remove(struct platform_device * op)935 static int mmp_pdma_remove(struct platform_device *op)
936 {
937 struct mmp_pdma_device *pdev = platform_get_drvdata(op);
938 struct mmp_pdma_phy *phy;
939 int i, irq = 0, irq_num = 0;
940
941 if (op->dev.of_node)
942 of_dma_controller_free(op->dev.of_node);
943
944 for (i = 0; i < pdev->dma_channels; i++) {
945 if (platform_get_irq(op, i) > 0)
946 irq_num++;
947 }
948
949 if (irq_num != pdev->dma_channels) {
950 irq = platform_get_irq(op, 0);
951 devm_free_irq(&op->dev, irq, pdev);
952 } else {
953 for (i = 0; i < pdev->dma_channels; i++) {
954 phy = &pdev->phy[i];
955 irq = platform_get_irq(op, i);
956 devm_free_irq(&op->dev, irq, phy);
957 }
958 }
959
960 dma_async_device_unregister(&pdev->device);
961 return 0;
962 }
963
mmp_pdma_chan_init(struct mmp_pdma_device * pdev,int idx,int irq)964 static int mmp_pdma_chan_init(struct mmp_pdma_device *pdev, int idx, int irq)
965 {
966 struct mmp_pdma_phy *phy = &pdev->phy[idx];
967 struct mmp_pdma_chan *chan;
968 int ret;
969
970 chan = devm_kzalloc(pdev->dev, sizeof(*chan), GFP_KERNEL);
971 if (chan == NULL)
972 return -ENOMEM;
973
974 phy->idx = idx;
975 phy->base = pdev->base;
976
977 if (irq) {
978 ret = devm_request_irq(pdev->dev, irq, mmp_pdma_chan_handler,
979 IRQF_SHARED, "pdma", phy);
980 if (ret) {
981 dev_err(pdev->dev, "channel request irq fail!\n");
982 return ret;
983 }
984 }
985
986 spin_lock_init(&chan->desc_lock);
987 chan->dev = pdev->dev;
988 chan->chan.device = &pdev->device;
989 tasklet_setup(&chan->tasklet, dma_do_tasklet);
990 INIT_LIST_HEAD(&chan->chain_pending);
991 INIT_LIST_HEAD(&chan->chain_running);
992
993 /* register virt channel to dma engine */
994 list_add_tail(&chan->chan.device_node, &pdev->device.channels);
995
996 return 0;
997 }
998
999 static const struct of_device_id mmp_pdma_dt_ids[] = {
1000 { .compatible = "marvell,pdma-1.0", },
1001 {}
1002 };
1003 MODULE_DEVICE_TABLE(of, mmp_pdma_dt_ids);
1004
mmp_pdma_dma_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)1005 static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec,
1006 struct of_dma *ofdma)
1007 {
1008 struct mmp_pdma_device *d = ofdma->of_dma_data;
1009 struct dma_chan *chan;
1010
1011 chan = dma_get_any_slave_channel(&d->device);
1012 if (!chan)
1013 return NULL;
1014
1015 to_mmp_pdma_chan(chan)->drcmr = dma_spec->args[0];
1016
1017 return chan;
1018 }
1019
mmp_pdma_probe(struct platform_device * op)1020 static int mmp_pdma_probe(struct platform_device *op)
1021 {
1022 struct mmp_pdma_device *pdev;
1023 const struct of_device_id *of_id;
1024 struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1025 int i, ret, irq = 0;
1026 int dma_channels = 0, irq_num = 0;
1027 const enum dma_slave_buswidth widths =
1028 DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
1029 DMA_SLAVE_BUSWIDTH_4_BYTES;
1030
1031 pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1032 if (!pdev)
1033 return -ENOMEM;
1034
1035 pdev->dev = &op->dev;
1036
1037 spin_lock_init(&pdev->phy_lock);
1038
1039 pdev->base = devm_platform_ioremap_resource(op, 0);
1040 if (IS_ERR(pdev->base))
1041 return PTR_ERR(pdev->base);
1042
1043 of_id = of_match_device(mmp_pdma_dt_ids, pdev->dev);
1044 if (of_id) {
1045 /* Parse new and deprecated dma-channels properties */
1046 if (of_property_read_u32(pdev->dev->of_node, "dma-channels",
1047 &dma_channels))
1048 of_property_read_u32(pdev->dev->of_node, "#dma-channels",
1049 &dma_channels);
1050 } else if (pdata && pdata->dma_channels) {
1051 dma_channels = pdata->dma_channels;
1052 } else {
1053 dma_channels = 32; /* default 32 channel */
1054 }
1055 pdev->dma_channels = dma_channels;
1056
1057 for (i = 0; i < dma_channels; i++) {
1058 if (platform_get_irq_optional(op, i) > 0)
1059 irq_num++;
1060 }
1061
1062 pdev->phy = devm_kcalloc(pdev->dev, dma_channels, sizeof(*pdev->phy),
1063 GFP_KERNEL);
1064 if (pdev->phy == NULL)
1065 return -ENOMEM;
1066
1067 INIT_LIST_HEAD(&pdev->device.channels);
1068
1069 if (irq_num != dma_channels) {
1070 /* all chan share one irq, demux inside */
1071 irq = platform_get_irq(op, 0);
1072 ret = devm_request_irq(pdev->dev, irq, mmp_pdma_int_handler,
1073 IRQF_SHARED, "pdma", pdev);
1074 if (ret)
1075 return ret;
1076 }
1077
1078 for (i = 0; i < dma_channels; i++) {
1079 irq = (irq_num != dma_channels) ? 0 : platform_get_irq(op, i);
1080 ret = mmp_pdma_chan_init(pdev, i, irq);
1081 if (ret)
1082 return ret;
1083 }
1084
1085 dma_cap_set(DMA_SLAVE, pdev->device.cap_mask);
1086 dma_cap_set(DMA_MEMCPY, pdev->device.cap_mask);
1087 dma_cap_set(DMA_CYCLIC, pdev->device.cap_mask);
1088 dma_cap_set(DMA_PRIVATE, pdev->device.cap_mask);
1089 pdev->device.dev = &op->dev;
1090 pdev->device.device_alloc_chan_resources = mmp_pdma_alloc_chan_resources;
1091 pdev->device.device_free_chan_resources = mmp_pdma_free_chan_resources;
1092 pdev->device.device_tx_status = mmp_pdma_tx_status;
1093 pdev->device.device_prep_dma_memcpy = mmp_pdma_prep_memcpy;
1094 pdev->device.device_prep_slave_sg = mmp_pdma_prep_slave_sg;
1095 pdev->device.device_prep_dma_cyclic = mmp_pdma_prep_dma_cyclic;
1096 pdev->device.device_issue_pending = mmp_pdma_issue_pending;
1097 pdev->device.device_config = mmp_pdma_config;
1098 pdev->device.device_terminate_all = mmp_pdma_terminate_all;
1099 pdev->device.copy_align = DMAENGINE_ALIGN_8_BYTES;
1100 pdev->device.src_addr_widths = widths;
1101 pdev->device.dst_addr_widths = widths;
1102 pdev->device.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1103 pdev->device.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1104
1105 if (pdev->dev->coherent_dma_mask)
1106 dma_set_mask(pdev->dev, pdev->dev->coherent_dma_mask);
1107 else
1108 dma_set_mask(pdev->dev, DMA_BIT_MASK(64));
1109
1110 ret = dma_async_device_register(&pdev->device);
1111 if (ret) {
1112 dev_err(pdev->device.dev, "unable to register\n");
1113 return ret;
1114 }
1115
1116 if (op->dev.of_node) {
1117 /* Device-tree DMA controller registration */
1118 ret = of_dma_controller_register(op->dev.of_node,
1119 mmp_pdma_dma_xlate, pdev);
1120 if (ret < 0) {
1121 dev_err(&op->dev, "of_dma_controller_register failed\n");
1122 dma_async_device_unregister(&pdev->device);
1123 return ret;
1124 }
1125 }
1126
1127 platform_set_drvdata(op, pdev);
1128 dev_info(pdev->device.dev, "initialized %d channels\n", dma_channels);
1129 return 0;
1130 }
1131
1132 static const struct platform_device_id mmp_pdma_id_table[] = {
1133 { "mmp-pdma", },
1134 { },
1135 };
1136
1137 static struct platform_driver mmp_pdma_driver = {
1138 .driver = {
1139 .name = "mmp-pdma",
1140 .of_match_table = mmp_pdma_dt_ids,
1141 },
1142 .id_table = mmp_pdma_id_table,
1143 .probe = mmp_pdma_probe,
1144 .remove = mmp_pdma_remove,
1145 };
1146
1147 module_platform_driver(mmp_pdma_driver);
1148
1149 MODULE_DESCRIPTION("MARVELL MMP Peripheral DMA Driver");
1150 MODULE_AUTHOR("Marvell International Ltd.");
1151 MODULE_LICENSE("GPL v2");
1152