1 // SPDX-License-Identifier:  GPL-2.0
2 // (C) 2017-2018 Synopsys, Inc. (www.synopsys.com)
3 
4 /*
5  * Synopsys DesignWare AXI DMA Controller driver.
6  *
7  * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
8  */
9 
10 #include <linux/bitops.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/dmaengine.h>
14 #include <linux/dmapool.h>
15 #include <linux/err.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/property.h>
24 #include <linux/types.h>
25 
26 #include "dw-axi-dmac.h"
27 #include "../dmaengine.h"
28 #include "../virt-dma.h"
29 
30 /*
31  * The set of bus widths supported by the DMA controller. DW AXI DMAC supports
32  * master data bus width up to 512 bits (for both AXI master interfaces), but
33  * it depends on IP block configurarion.
34  */
35 #define AXI_DMA_BUSWIDTHS		  \
36 	(DMA_SLAVE_BUSWIDTH_1_BYTE	| \
37 	DMA_SLAVE_BUSWIDTH_2_BYTES	| \
38 	DMA_SLAVE_BUSWIDTH_4_BYTES	| \
39 	DMA_SLAVE_BUSWIDTH_8_BYTES	| \
40 	DMA_SLAVE_BUSWIDTH_16_BYTES	| \
41 	DMA_SLAVE_BUSWIDTH_32_BYTES	| \
42 	DMA_SLAVE_BUSWIDTH_64_BYTES)
43 
44 static inline void
45 axi_dma_iowrite32(struct axi_dma_chip *chip, u32 reg, u32 val)
46 {
47 	iowrite32(val, chip->regs + reg);
48 }
49 
50 static inline u32 axi_dma_ioread32(struct axi_dma_chip *chip, u32 reg)
51 {
52 	return ioread32(chip->regs + reg);
53 }
54 
55 static inline void
56 axi_chan_iowrite32(struct axi_dma_chan *chan, u32 reg, u32 val)
57 {
58 	iowrite32(val, chan->chan_regs + reg);
59 }
60 
61 static inline u32 axi_chan_ioread32(struct axi_dma_chan *chan, u32 reg)
62 {
63 	return ioread32(chan->chan_regs + reg);
64 }
65 
66 static inline void
67 axi_chan_iowrite64(struct axi_dma_chan *chan, u32 reg, u64 val)
68 {
69 	/*
70 	 * We split one 64 bit write for two 32 bit write as some HW doesn't
71 	 * support 64 bit access.
72 	 */
73 	iowrite32(lower_32_bits(val), chan->chan_regs + reg);
74 	iowrite32(upper_32_bits(val), chan->chan_regs + reg + 4);
75 }
76 
77 static inline void axi_dma_disable(struct axi_dma_chip *chip)
78 {
79 	u32 val;
80 
81 	val = axi_dma_ioread32(chip, DMAC_CFG);
82 	val &= ~DMAC_EN_MASK;
83 	axi_dma_iowrite32(chip, DMAC_CFG, val);
84 }
85 
86 static inline void axi_dma_enable(struct axi_dma_chip *chip)
87 {
88 	u32 val;
89 
90 	val = axi_dma_ioread32(chip, DMAC_CFG);
91 	val |= DMAC_EN_MASK;
92 	axi_dma_iowrite32(chip, DMAC_CFG, val);
93 }
94 
95 static inline void axi_dma_irq_disable(struct axi_dma_chip *chip)
96 {
97 	u32 val;
98 
99 	val = axi_dma_ioread32(chip, DMAC_CFG);
100 	val &= ~INT_EN_MASK;
101 	axi_dma_iowrite32(chip, DMAC_CFG, val);
102 }
103 
104 static inline void axi_dma_irq_enable(struct axi_dma_chip *chip)
105 {
106 	u32 val;
107 
108 	val = axi_dma_ioread32(chip, DMAC_CFG);
109 	val |= INT_EN_MASK;
110 	axi_dma_iowrite32(chip, DMAC_CFG, val);
111 }
112 
113 static inline void axi_chan_irq_disable(struct axi_dma_chan *chan, u32 irq_mask)
114 {
115 	u32 val;
116 
117 	if (likely(irq_mask == DWAXIDMAC_IRQ_ALL)) {
118 		axi_chan_iowrite32(chan, CH_INTSTATUS_ENA, DWAXIDMAC_IRQ_NONE);
119 	} else {
120 		val = axi_chan_ioread32(chan, CH_INTSTATUS_ENA);
121 		val &= ~irq_mask;
122 		axi_chan_iowrite32(chan, CH_INTSTATUS_ENA, val);
123 	}
124 }
125 
126 static inline void axi_chan_irq_set(struct axi_dma_chan *chan, u32 irq_mask)
127 {
128 	axi_chan_iowrite32(chan, CH_INTSTATUS_ENA, irq_mask);
129 }
130 
131 static inline void axi_chan_irq_sig_set(struct axi_dma_chan *chan, u32 irq_mask)
132 {
133 	axi_chan_iowrite32(chan, CH_INTSIGNAL_ENA, irq_mask);
134 }
135 
136 static inline void axi_chan_irq_clear(struct axi_dma_chan *chan, u32 irq_mask)
137 {
138 	axi_chan_iowrite32(chan, CH_INTCLEAR, irq_mask);
139 }
140 
141 static inline u32 axi_chan_irq_read(struct axi_dma_chan *chan)
142 {
143 	return axi_chan_ioread32(chan, CH_INTSTATUS);
144 }
145 
146 static inline void axi_chan_disable(struct axi_dma_chan *chan)
147 {
148 	u32 val;
149 
150 	val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
151 	val &= ~(BIT(chan->id) << DMAC_CHAN_EN_SHIFT);
152 	val |=   BIT(chan->id) << DMAC_CHAN_EN_WE_SHIFT;
153 	axi_dma_iowrite32(chan->chip, DMAC_CHEN, val);
154 }
155 
156 static inline void axi_chan_enable(struct axi_dma_chan *chan)
157 {
158 	u32 val;
159 
160 	val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
161 	val |= BIT(chan->id) << DMAC_CHAN_EN_SHIFT |
162 	       BIT(chan->id) << DMAC_CHAN_EN_WE_SHIFT;
163 	axi_dma_iowrite32(chan->chip, DMAC_CHEN, val);
164 }
165 
166 static inline bool axi_chan_is_hw_enable(struct axi_dma_chan *chan)
167 {
168 	u32 val;
169 
170 	val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
171 
172 	return !!(val & (BIT(chan->id) << DMAC_CHAN_EN_SHIFT));
173 }
174 
175 static void axi_dma_hw_init(struct axi_dma_chip *chip)
176 {
177 	u32 i;
178 
179 	for (i = 0; i < chip->dw->hdata->nr_channels; i++) {
180 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
181 		axi_chan_disable(&chip->dw->chan[i]);
182 	}
183 }
184 
185 static u32 axi_chan_get_xfer_width(struct axi_dma_chan *chan, dma_addr_t src,
186 				   dma_addr_t dst, size_t len)
187 {
188 	u32 max_width = chan->chip->dw->hdata->m_data_width;
189 
190 	return __ffs(src | dst | len | BIT(max_width));
191 }
192 
193 static inline const char *axi_chan_name(struct axi_dma_chan *chan)
194 {
195 	return dma_chan_name(&chan->vc.chan);
196 }
197 
198 static struct axi_dma_desc *axi_desc_get(struct axi_dma_chan *chan)
199 {
200 	struct dw_axi_dma *dw = chan->chip->dw;
201 	struct axi_dma_desc *desc;
202 	dma_addr_t phys;
203 
204 	desc = dma_pool_zalloc(dw->desc_pool, GFP_NOWAIT, &phys);
205 	if (unlikely(!desc)) {
206 		dev_err(chan2dev(chan), "%s: not enough descriptors available\n",
207 			axi_chan_name(chan));
208 		return NULL;
209 	}
210 
211 	atomic_inc(&chan->descs_allocated);
212 	INIT_LIST_HEAD(&desc->xfer_list);
213 	desc->vd.tx.phys = phys;
214 	desc->chan = chan;
215 
216 	return desc;
217 }
218 
219 static void axi_desc_put(struct axi_dma_desc *desc)
220 {
221 	struct axi_dma_chan *chan = desc->chan;
222 	struct dw_axi_dma *dw = chan->chip->dw;
223 	struct axi_dma_desc *child, *_next;
224 	unsigned int descs_put = 0;
225 
226 	list_for_each_entry_safe(child, _next, &desc->xfer_list, xfer_list) {
227 		list_del(&child->xfer_list);
228 		dma_pool_free(dw->desc_pool, child, child->vd.tx.phys);
229 		descs_put++;
230 	}
231 
232 	dma_pool_free(dw->desc_pool, desc, desc->vd.tx.phys);
233 	descs_put++;
234 
235 	atomic_sub(descs_put, &chan->descs_allocated);
236 	dev_vdbg(chan2dev(chan), "%s: %d descs put, %d still allocated\n",
237 		axi_chan_name(chan), descs_put,
238 		atomic_read(&chan->descs_allocated));
239 }
240 
241 static void vchan_desc_put(struct virt_dma_desc *vdesc)
242 {
243 	axi_desc_put(vd_to_axi_desc(vdesc));
244 }
245 
246 static enum dma_status
247 dma_chan_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
248 		  struct dma_tx_state *txstate)
249 {
250 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
251 	enum dma_status ret;
252 
253 	ret = dma_cookie_status(dchan, cookie, txstate);
254 
255 	if (chan->is_paused && ret == DMA_IN_PROGRESS)
256 		ret = DMA_PAUSED;
257 
258 	return ret;
259 }
260 
261 static void write_desc_llp(struct axi_dma_desc *desc, dma_addr_t adr)
262 {
263 	desc->lli.llp = cpu_to_le64(adr);
264 }
265 
266 static void write_chan_llp(struct axi_dma_chan *chan, dma_addr_t adr)
267 {
268 	axi_chan_iowrite64(chan, CH_LLP, adr);
269 }
270 
271 /* Called in chan locked context */
272 static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
273 				      struct axi_dma_desc *first)
274 {
275 	u32 priority = chan->chip->dw->hdata->priority[chan->id];
276 	u32 reg, irq_mask;
277 	u8 lms = 0; /* Select AXI0 master for LLI fetching */
278 
279 	if (unlikely(axi_chan_is_hw_enable(chan))) {
280 		dev_err(chan2dev(chan), "%s is non-idle!\n",
281 			axi_chan_name(chan));
282 
283 		return;
284 	}
285 
286 	axi_dma_enable(chan->chip);
287 
288 	reg = (DWAXIDMAC_MBLK_TYPE_LL << CH_CFG_L_DST_MULTBLK_TYPE_POS |
289 	       DWAXIDMAC_MBLK_TYPE_LL << CH_CFG_L_SRC_MULTBLK_TYPE_POS);
290 	axi_chan_iowrite32(chan, CH_CFG_L, reg);
291 
292 	reg = (DWAXIDMAC_TT_FC_MEM_TO_MEM_DMAC << CH_CFG_H_TT_FC_POS |
293 	       priority << CH_CFG_H_PRIORITY_POS |
294 	       DWAXIDMAC_HS_SEL_HW << CH_CFG_H_HS_SEL_DST_POS |
295 	       DWAXIDMAC_HS_SEL_HW << CH_CFG_H_HS_SEL_SRC_POS);
296 	axi_chan_iowrite32(chan, CH_CFG_H, reg);
297 
298 	write_chan_llp(chan, first->vd.tx.phys | lms);
299 
300 	irq_mask = DWAXIDMAC_IRQ_DMA_TRF | DWAXIDMAC_IRQ_ALL_ERR;
301 	axi_chan_irq_sig_set(chan, irq_mask);
302 
303 	/* Generate 'suspend' status but don't generate interrupt */
304 	irq_mask |= DWAXIDMAC_IRQ_SUSPENDED;
305 	axi_chan_irq_set(chan, irq_mask);
306 
307 	axi_chan_enable(chan);
308 }
309 
310 static void axi_chan_start_first_queued(struct axi_dma_chan *chan)
311 {
312 	struct axi_dma_desc *desc;
313 	struct virt_dma_desc *vd;
314 
315 	vd = vchan_next_desc(&chan->vc);
316 	if (!vd)
317 		return;
318 
319 	desc = vd_to_axi_desc(vd);
320 	dev_vdbg(chan2dev(chan), "%s: started %u\n", axi_chan_name(chan),
321 		vd->tx.cookie);
322 	axi_chan_block_xfer_start(chan, desc);
323 }
324 
325 static void dma_chan_issue_pending(struct dma_chan *dchan)
326 {
327 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
328 	unsigned long flags;
329 
330 	spin_lock_irqsave(&chan->vc.lock, flags);
331 	if (vchan_issue_pending(&chan->vc))
332 		axi_chan_start_first_queued(chan);
333 	spin_unlock_irqrestore(&chan->vc.lock, flags);
334 }
335 
336 static int dma_chan_alloc_chan_resources(struct dma_chan *dchan)
337 {
338 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
339 
340 	/* ASSERT: channel is idle */
341 	if (axi_chan_is_hw_enable(chan)) {
342 		dev_err(chan2dev(chan), "%s is non-idle!\n",
343 			axi_chan_name(chan));
344 		return -EBUSY;
345 	}
346 
347 	dev_vdbg(dchan2dev(dchan), "%s: allocating\n", axi_chan_name(chan));
348 
349 	pm_runtime_get(chan->chip->dev);
350 
351 	return 0;
352 }
353 
354 static void dma_chan_free_chan_resources(struct dma_chan *dchan)
355 {
356 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
357 
358 	/* ASSERT: channel is idle */
359 	if (axi_chan_is_hw_enable(chan))
360 		dev_err(dchan2dev(dchan), "%s is non-idle!\n",
361 			axi_chan_name(chan));
362 
363 	axi_chan_disable(chan);
364 	axi_chan_irq_disable(chan, DWAXIDMAC_IRQ_ALL);
365 
366 	vchan_free_chan_resources(&chan->vc);
367 
368 	dev_vdbg(dchan2dev(dchan),
369 		 "%s: free resources, descriptor still allocated: %u\n",
370 		 axi_chan_name(chan), atomic_read(&chan->descs_allocated));
371 
372 	pm_runtime_put(chan->chip->dev);
373 }
374 
375 /*
376  * If DW_axi_dmac sees CHx_CTL.ShadowReg_Or_LLI_Last bit of the fetched LLI
377  * as 1, it understands that the current block is the final block in the
378  * transfer and completes the DMA transfer operation at the end of current
379  * block transfer.
380  */
381 static void set_desc_last(struct axi_dma_desc *desc)
382 {
383 	u32 val;
384 
385 	val = le32_to_cpu(desc->lli.ctl_hi);
386 	val |= CH_CTL_H_LLI_LAST;
387 	desc->lli.ctl_hi = cpu_to_le32(val);
388 }
389 
390 static void write_desc_sar(struct axi_dma_desc *desc, dma_addr_t adr)
391 {
392 	desc->lli.sar = cpu_to_le64(adr);
393 }
394 
395 static void write_desc_dar(struct axi_dma_desc *desc, dma_addr_t adr)
396 {
397 	desc->lli.dar = cpu_to_le64(adr);
398 }
399 
400 static void set_desc_src_master(struct axi_dma_desc *desc)
401 {
402 	u32 val;
403 
404 	/* Select AXI0 for source master */
405 	val = le32_to_cpu(desc->lli.ctl_lo);
406 	val &= ~CH_CTL_L_SRC_MAST;
407 	desc->lli.ctl_lo = cpu_to_le32(val);
408 }
409 
410 static void set_desc_dest_master(struct axi_dma_desc *desc)
411 {
412 	u32 val;
413 
414 	/* Select AXI1 for source master if available */
415 	val = le32_to_cpu(desc->lli.ctl_lo);
416 	if (desc->chan->chip->dw->hdata->nr_masters > 1)
417 		val |= CH_CTL_L_DST_MAST;
418 	else
419 		val &= ~CH_CTL_L_DST_MAST;
420 
421 	desc->lli.ctl_lo = cpu_to_le32(val);
422 }
423 
424 static struct dma_async_tx_descriptor *
425 dma_chan_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dst_adr,
426 			 dma_addr_t src_adr, size_t len, unsigned long flags)
427 {
428 	struct axi_dma_desc *first = NULL, *desc = NULL, *prev = NULL;
429 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
430 	size_t block_ts, max_block_ts, xfer_len;
431 	u32 xfer_width, reg;
432 	u8 lms = 0; /* Select AXI0 master for LLI fetching */
433 
434 	dev_dbg(chan2dev(chan), "%s: memcpy: src: %pad dst: %pad length: %zd flags: %#lx",
435 		axi_chan_name(chan), &src_adr, &dst_adr, len, flags);
436 
437 	max_block_ts = chan->chip->dw->hdata->block_size[chan->id];
438 
439 	while (len) {
440 		xfer_len = len;
441 
442 		/*
443 		 * Take care for the alignment.
444 		 * Actually source and destination widths can be different, but
445 		 * make them same to be simpler.
446 		 */
447 		xfer_width = axi_chan_get_xfer_width(chan, src_adr, dst_adr, xfer_len);
448 
449 		/*
450 		 * block_ts indicates the total number of data of width
451 		 * to be transferred in a DMA block transfer.
452 		 * BLOCK_TS register should be set to block_ts - 1
453 		 */
454 		block_ts = xfer_len >> xfer_width;
455 		if (block_ts > max_block_ts) {
456 			block_ts = max_block_ts;
457 			xfer_len = max_block_ts << xfer_width;
458 		}
459 
460 		desc = axi_desc_get(chan);
461 		if (unlikely(!desc))
462 			goto err_desc_get;
463 
464 		write_desc_sar(desc, src_adr);
465 		write_desc_dar(desc, dst_adr);
466 		desc->lli.block_ts_lo = cpu_to_le32(block_ts - 1);
467 
468 		reg = CH_CTL_H_LLI_VALID;
469 		if (chan->chip->dw->hdata->restrict_axi_burst_len) {
470 			u32 burst_len = chan->chip->dw->hdata->axi_rw_burst_len;
471 
472 			reg |= (CH_CTL_H_ARLEN_EN |
473 				burst_len << CH_CTL_H_ARLEN_POS |
474 				CH_CTL_H_AWLEN_EN |
475 				burst_len << CH_CTL_H_AWLEN_POS);
476 		}
477 		desc->lli.ctl_hi = cpu_to_le32(reg);
478 
479 		reg = (DWAXIDMAC_BURST_TRANS_LEN_4 << CH_CTL_L_DST_MSIZE_POS |
480 		       DWAXIDMAC_BURST_TRANS_LEN_4 << CH_CTL_L_SRC_MSIZE_POS |
481 		       xfer_width << CH_CTL_L_DST_WIDTH_POS |
482 		       xfer_width << CH_CTL_L_SRC_WIDTH_POS |
483 		       DWAXIDMAC_CH_CTL_L_INC << CH_CTL_L_DST_INC_POS |
484 		       DWAXIDMAC_CH_CTL_L_INC << CH_CTL_L_SRC_INC_POS);
485 		desc->lli.ctl_lo = cpu_to_le32(reg);
486 
487 		set_desc_src_master(desc);
488 		set_desc_dest_master(desc);
489 
490 		/* Manage transfer list (xfer_list) */
491 		if (!first) {
492 			first = desc;
493 		} else {
494 			list_add_tail(&desc->xfer_list, &first->xfer_list);
495 			write_desc_llp(prev, desc->vd.tx.phys | lms);
496 		}
497 		prev = desc;
498 
499 		/* update the length and addresses for the next loop cycle */
500 		len -= xfer_len;
501 		dst_adr += xfer_len;
502 		src_adr += xfer_len;
503 	}
504 
505 	/* Total len of src/dest sg == 0, so no descriptor were allocated */
506 	if (unlikely(!first))
507 		return NULL;
508 
509 	/* Set end-of-link to the last link descriptor of list */
510 	set_desc_last(desc);
511 
512 	return vchan_tx_prep(&chan->vc, &first->vd, flags);
513 
514 err_desc_get:
515 	if (first)
516 		axi_desc_put(first);
517 	return NULL;
518 }
519 
520 static void axi_chan_dump_lli(struct axi_dma_chan *chan,
521 			      struct axi_dma_desc *desc)
522 {
523 	dev_err(dchan2dev(&chan->vc.chan),
524 		"SAR: 0x%llx DAR: 0x%llx LLP: 0x%llx BTS 0x%x CTL: 0x%x:%08x",
525 		le64_to_cpu(desc->lli.sar),
526 		le64_to_cpu(desc->lli.dar),
527 		le64_to_cpu(desc->lli.llp),
528 		le32_to_cpu(desc->lli.block_ts_lo),
529 		le32_to_cpu(desc->lli.ctl_hi),
530 		le32_to_cpu(desc->lli.ctl_lo));
531 }
532 
533 static void axi_chan_list_dump_lli(struct axi_dma_chan *chan,
534 				   struct axi_dma_desc *desc_head)
535 {
536 	struct axi_dma_desc *desc;
537 
538 	axi_chan_dump_lli(chan, desc_head);
539 	list_for_each_entry(desc, &desc_head->xfer_list, xfer_list)
540 		axi_chan_dump_lli(chan, desc);
541 }
542 
543 static noinline void axi_chan_handle_err(struct axi_dma_chan *chan, u32 status)
544 {
545 	struct virt_dma_desc *vd;
546 	unsigned long flags;
547 
548 	spin_lock_irqsave(&chan->vc.lock, flags);
549 
550 	axi_chan_disable(chan);
551 
552 	/* The bad descriptor currently is in the head of vc list */
553 	vd = vchan_next_desc(&chan->vc);
554 	/* Remove the completed descriptor from issued list */
555 	list_del(&vd->node);
556 
557 	/* WARN about bad descriptor */
558 	dev_err(chan2dev(chan),
559 		"Bad descriptor submitted for %s, cookie: %d, irq: 0x%08x\n",
560 		axi_chan_name(chan), vd->tx.cookie, status);
561 	axi_chan_list_dump_lli(chan, vd_to_axi_desc(vd));
562 
563 	vchan_cookie_complete(vd);
564 
565 	/* Try to restart the controller */
566 	axi_chan_start_first_queued(chan);
567 
568 	spin_unlock_irqrestore(&chan->vc.lock, flags);
569 }
570 
571 static void axi_chan_block_xfer_complete(struct axi_dma_chan *chan)
572 {
573 	struct virt_dma_desc *vd;
574 	unsigned long flags;
575 
576 	spin_lock_irqsave(&chan->vc.lock, flags);
577 	if (unlikely(axi_chan_is_hw_enable(chan))) {
578 		dev_err(chan2dev(chan), "BUG: %s caught DWAXIDMAC_IRQ_DMA_TRF, but channel not idle!\n",
579 			axi_chan_name(chan));
580 		axi_chan_disable(chan);
581 	}
582 
583 	/* The completed descriptor currently is in the head of vc list */
584 	vd = vchan_next_desc(&chan->vc);
585 	/* Remove the completed descriptor from issued list before completing */
586 	list_del(&vd->node);
587 	vchan_cookie_complete(vd);
588 
589 	/* Submit queued descriptors after processing the completed ones */
590 	axi_chan_start_first_queued(chan);
591 
592 	spin_unlock_irqrestore(&chan->vc.lock, flags);
593 }
594 
595 static irqreturn_t dw_axi_dma_interrupt(int irq, void *dev_id)
596 {
597 	struct axi_dma_chip *chip = dev_id;
598 	struct dw_axi_dma *dw = chip->dw;
599 	struct axi_dma_chan *chan;
600 
601 	u32 status, i;
602 
603 	/* Disable DMAC inerrupts. We'll enable them after processing chanels */
604 	axi_dma_irq_disable(chip);
605 
606 	/* Poll, clear and process every chanel interrupt status */
607 	for (i = 0; i < dw->hdata->nr_channels; i++) {
608 		chan = &dw->chan[i];
609 		status = axi_chan_irq_read(chan);
610 		axi_chan_irq_clear(chan, status);
611 
612 		dev_vdbg(chip->dev, "%s %u IRQ status: 0x%08x\n",
613 			axi_chan_name(chan), i, status);
614 
615 		if (status & DWAXIDMAC_IRQ_ALL_ERR)
616 			axi_chan_handle_err(chan, status);
617 		else if (status & DWAXIDMAC_IRQ_DMA_TRF)
618 			axi_chan_block_xfer_complete(chan);
619 	}
620 
621 	/* Re-enable interrupts */
622 	axi_dma_irq_enable(chip);
623 
624 	return IRQ_HANDLED;
625 }
626 
627 static int dma_chan_terminate_all(struct dma_chan *dchan)
628 {
629 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
630 	unsigned long flags;
631 	LIST_HEAD(head);
632 
633 	spin_lock_irqsave(&chan->vc.lock, flags);
634 
635 	axi_chan_disable(chan);
636 
637 	vchan_get_all_descriptors(&chan->vc, &head);
638 
639 	/*
640 	 * As vchan_dma_desc_free_list can access to desc_allocated list
641 	 * we need to call it in vc.lock context.
642 	 */
643 	vchan_dma_desc_free_list(&chan->vc, &head);
644 
645 	spin_unlock_irqrestore(&chan->vc.lock, flags);
646 
647 	dev_vdbg(dchan2dev(dchan), "terminated: %s\n", axi_chan_name(chan));
648 
649 	return 0;
650 }
651 
652 static int dma_chan_pause(struct dma_chan *dchan)
653 {
654 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
655 	unsigned long flags;
656 	unsigned int timeout = 20; /* timeout iterations */
657 	u32 val;
658 
659 	spin_lock_irqsave(&chan->vc.lock, flags);
660 
661 	val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
662 	val |= BIT(chan->id) << DMAC_CHAN_SUSP_SHIFT |
663 	       BIT(chan->id) << DMAC_CHAN_SUSP_WE_SHIFT;
664 	axi_dma_iowrite32(chan->chip, DMAC_CHEN, val);
665 
666 	do  {
667 		if (axi_chan_irq_read(chan) & DWAXIDMAC_IRQ_SUSPENDED)
668 			break;
669 
670 		udelay(2);
671 	} while (--timeout);
672 
673 	axi_chan_irq_clear(chan, DWAXIDMAC_IRQ_SUSPENDED);
674 
675 	chan->is_paused = true;
676 
677 	spin_unlock_irqrestore(&chan->vc.lock, flags);
678 
679 	return timeout ? 0 : -EAGAIN;
680 }
681 
682 /* Called in chan locked context */
683 static inline void axi_chan_resume(struct axi_dma_chan *chan)
684 {
685 	u32 val;
686 
687 	val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
688 	val &= ~(BIT(chan->id) << DMAC_CHAN_SUSP_SHIFT);
689 	val |=  (BIT(chan->id) << DMAC_CHAN_SUSP_WE_SHIFT);
690 	axi_dma_iowrite32(chan->chip, DMAC_CHEN, val);
691 
692 	chan->is_paused = false;
693 }
694 
695 static int dma_chan_resume(struct dma_chan *dchan)
696 {
697 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
698 	unsigned long flags;
699 
700 	spin_lock_irqsave(&chan->vc.lock, flags);
701 
702 	if (chan->is_paused)
703 		axi_chan_resume(chan);
704 
705 	spin_unlock_irqrestore(&chan->vc.lock, flags);
706 
707 	return 0;
708 }
709 
710 static int axi_dma_suspend(struct axi_dma_chip *chip)
711 {
712 	axi_dma_irq_disable(chip);
713 	axi_dma_disable(chip);
714 
715 	clk_disable_unprepare(chip->core_clk);
716 	clk_disable_unprepare(chip->cfgr_clk);
717 
718 	return 0;
719 }
720 
721 static int axi_dma_resume(struct axi_dma_chip *chip)
722 {
723 	int ret;
724 
725 	ret = clk_prepare_enable(chip->cfgr_clk);
726 	if (ret < 0)
727 		return ret;
728 
729 	ret = clk_prepare_enable(chip->core_clk);
730 	if (ret < 0)
731 		return ret;
732 
733 	axi_dma_enable(chip);
734 	axi_dma_irq_enable(chip);
735 
736 	return 0;
737 }
738 
739 static int __maybe_unused axi_dma_runtime_suspend(struct device *dev)
740 {
741 	struct axi_dma_chip *chip = dev_get_drvdata(dev);
742 
743 	return axi_dma_suspend(chip);
744 }
745 
746 static int __maybe_unused axi_dma_runtime_resume(struct device *dev)
747 {
748 	struct axi_dma_chip *chip = dev_get_drvdata(dev);
749 
750 	return axi_dma_resume(chip);
751 }
752 
753 static int parse_device_properties(struct axi_dma_chip *chip)
754 {
755 	struct device *dev = chip->dev;
756 	u32 tmp, carr[DMAC_MAX_CHANNELS];
757 	int ret;
758 
759 	ret = device_property_read_u32(dev, "dma-channels", &tmp);
760 	if (ret)
761 		return ret;
762 	if (tmp == 0 || tmp > DMAC_MAX_CHANNELS)
763 		return -EINVAL;
764 
765 	chip->dw->hdata->nr_channels = tmp;
766 
767 	ret = device_property_read_u32(dev, "snps,dma-masters", &tmp);
768 	if (ret)
769 		return ret;
770 	if (tmp == 0 || tmp > DMAC_MAX_MASTERS)
771 		return -EINVAL;
772 
773 	chip->dw->hdata->nr_masters = tmp;
774 
775 	ret = device_property_read_u32(dev, "snps,data-width", &tmp);
776 	if (ret)
777 		return ret;
778 	if (tmp > DWAXIDMAC_TRANS_WIDTH_MAX)
779 		return -EINVAL;
780 
781 	chip->dw->hdata->m_data_width = tmp;
782 
783 	ret = device_property_read_u32_array(dev, "snps,block-size", carr,
784 					     chip->dw->hdata->nr_channels);
785 	if (ret)
786 		return ret;
787 	for (tmp = 0; tmp < chip->dw->hdata->nr_channels; tmp++) {
788 		if (carr[tmp] == 0 || carr[tmp] > DMAC_MAX_BLK_SIZE)
789 			return -EINVAL;
790 
791 		chip->dw->hdata->block_size[tmp] = carr[tmp];
792 	}
793 
794 	ret = device_property_read_u32_array(dev, "snps,priority", carr,
795 					     chip->dw->hdata->nr_channels);
796 	if (ret)
797 		return ret;
798 	/* Priority value must be programmed within [0:nr_channels-1] range */
799 	for (tmp = 0; tmp < chip->dw->hdata->nr_channels; tmp++) {
800 		if (carr[tmp] >= chip->dw->hdata->nr_channels)
801 			return -EINVAL;
802 
803 		chip->dw->hdata->priority[tmp] = carr[tmp];
804 	}
805 
806 	/* axi-max-burst-len is optional property */
807 	ret = device_property_read_u32(dev, "snps,axi-max-burst-len", &tmp);
808 	if (!ret) {
809 		if (tmp > DWAXIDMAC_ARWLEN_MAX + 1)
810 			return -EINVAL;
811 		if (tmp < DWAXIDMAC_ARWLEN_MIN + 1)
812 			return -EINVAL;
813 
814 		chip->dw->hdata->restrict_axi_burst_len = true;
815 		chip->dw->hdata->axi_rw_burst_len = tmp - 1;
816 	}
817 
818 	return 0;
819 }
820 
821 static int dw_probe(struct platform_device *pdev)
822 {
823 	struct axi_dma_chip *chip;
824 	struct resource *mem;
825 	struct dw_axi_dma *dw;
826 	struct dw_axi_dma_hcfg *hdata;
827 	u32 i;
828 	int ret;
829 
830 	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
831 	if (!chip)
832 		return -ENOMEM;
833 
834 	dw = devm_kzalloc(&pdev->dev, sizeof(*dw), GFP_KERNEL);
835 	if (!dw)
836 		return -ENOMEM;
837 
838 	hdata = devm_kzalloc(&pdev->dev, sizeof(*hdata), GFP_KERNEL);
839 	if (!hdata)
840 		return -ENOMEM;
841 
842 	chip->dw = dw;
843 	chip->dev = &pdev->dev;
844 	chip->dw->hdata = hdata;
845 
846 	chip->irq = platform_get_irq(pdev, 0);
847 	if (chip->irq < 0)
848 		return chip->irq;
849 
850 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
851 	chip->regs = devm_ioremap_resource(chip->dev, mem);
852 	if (IS_ERR(chip->regs))
853 		return PTR_ERR(chip->regs);
854 
855 	chip->core_clk = devm_clk_get(chip->dev, "core-clk");
856 	if (IS_ERR(chip->core_clk))
857 		return PTR_ERR(chip->core_clk);
858 
859 	chip->cfgr_clk = devm_clk_get(chip->dev, "cfgr-clk");
860 	if (IS_ERR(chip->cfgr_clk))
861 		return PTR_ERR(chip->cfgr_clk);
862 
863 	ret = parse_device_properties(chip);
864 	if (ret)
865 		return ret;
866 
867 	dw->chan = devm_kcalloc(chip->dev, hdata->nr_channels,
868 				sizeof(*dw->chan), GFP_KERNEL);
869 	if (!dw->chan)
870 		return -ENOMEM;
871 
872 	ret = devm_request_irq(chip->dev, chip->irq, dw_axi_dma_interrupt,
873 			       IRQF_SHARED, KBUILD_MODNAME, chip);
874 	if (ret)
875 		return ret;
876 
877 	/* Lli address must be aligned to a 64-byte boundary */
878 	dw->desc_pool = dmam_pool_create(KBUILD_MODNAME, chip->dev,
879 					 sizeof(struct axi_dma_desc), 64, 0);
880 	if (!dw->desc_pool) {
881 		dev_err(chip->dev, "No memory for descriptors dma pool\n");
882 		return -ENOMEM;
883 	}
884 
885 	INIT_LIST_HEAD(&dw->dma.channels);
886 	for (i = 0; i < hdata->nr_channels; i++) {
887 		struct axi_dma_chan *chan = &dw->chan[i];
888 
889 		chan->chip = chip;
890 		chan->id = i;
891 		chan->chan_regs = chip->regs + COMMON_REG_LEN + i * CHAN_REG_LEN;
892 		atomic_set(&chan->descs_allocated, 0);
893 
894 		chan->vc.desc_free = vchan_desc_put;
895 		vchan_init(&chan->vc, &dw->dma);
896 	}
897 
898 	/* Set capabilities */
899 	dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
900 
901 	/* DMA capabilities */
902 	dw->dma.chancnt = hdata->nr_channels;
903 	dw->dma.src_addr_widths = AXI_DMA_BUSWIDTHS;
904 	dw->dma.dst_addr_widths = AXI_DMA_BUSWIDTHS;
905 	dw->dma.directions = BIT(DMA_MEM_TO_MEM);
906 	dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
907 
908 	dw->dma.dev = chip->dev;
909 	dw->dma.device_tx_status = dma_chan_tx_status;
910 	dw->dma.device_issue_pending = dma_chan_issue_pending;
911 	dw->dma.device_terminate_all = dma_chan_terminate_all;
912 	dw->dma.device_pause = dma_chan_pause;
913 	dw->dma.device_resume = dma_chan_resume;
914 
915 	dw->dma.device_alloc_chan_resources = dma_chan_alloc_chan_resources;
916 	dw->dma.device_free_chan_resources = dma_chan_free_chan_resources;
917 
918 	dw->dma.device_prep_dma_memcpy = dma_chan_prep_dma_memcpy;
919 
920 	platform_set_drvdata(pdev, chip);
921 
922 	pm_runtime_enable(chip->dev);
923 
924 	/*
925 	 * We can't just call pm_runtime_get here instead of
926 	 * pm_runtime_get_noresume + axi_dma_resume because we need
927 	 * driver to work also without Runtime PM.
928 	 */
929 	pm_runtime_get_noresume(chip->dev);
930 	ret = axi_dma_resume(chip);
931 	if (ret < 0)
932 		goto err_pm_disable;
933 
934 	axi_dma_hw_init(chip);
935 
936 	pm_runtime_put(chip->dev);
937 
938 	ret = dmaenginem_async_device_register(&dw->dma);
939 	if (ret)
940 		goto err_pm_disable;
941 
942 	dev_info(chip->dev, "DesignWare AXI DMA Controller, %d channels\n",
943 		 dw->hdata->nr_channels);
944 
945 	return 0;
946 
947 err_pm_disable:
948 	pm_runtime_disable(chip->dev);
949 
950 	return ret;
951 }
952 
953 static int dw_remove(struct platform_device *pdev)
954 {
955 	struct axi_dma_chip *chip = platform_get_drvdata(pdev);
956 	struct dw_axi_dma *dw = chip->dw;
957 	struct axi_dma_chan *chan, *_chan;
958 	u32 i;
959 
960 	/* Enable clk before accessing to registers */
961 	clk_prepare_enable(chip->cfgr_clk);
962 	clk_prepare_enable(chip->core_clk);
963 	axi_dma_irq_disable(chip);
964 	for (i = 0; i < dw->hdata->nr_channels; i++) {
965 		axi_chan_disable(&chip->dw->chan[i]);
966 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
967 	}
968 	axi_dma_disable(chip);
969 
970 	pm_runtime_disable(chip->dev);
971 	axi_dma_suspend(chip);
972 
973 	devm_free_irq(chip->dev, chip->irq, chip);
974 
975 	list_for_each_entry_safe(chan, _chan, &dw->dma.channels,
976 			vc.chan.device_node) {
977 		list_del(&chan->vc.chan.device_node);
978 		tasklet_kill(&chan->vc.task);
979 	}
980 
981 	return 0;
982 }
983 
984 static const struct dev_pm_ops dw_axi_dma_pm_ops = {
985 	SET_RUNTIME_PM_OPS(axi_dma_runtime_suspend, axi_dma_runtime_resume, NULL)
986 };
987 
988 static const struct of_device_id dw_dma_of_id_table[] = {
989 	{ .compatible = "snps,axi-dma-1.01a" },
990 	{}
991 };
992 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
993 
994 static struct platform_driver dw_driver = {
995 	.probe		= dw_probe,
996 	.remove		= dw_remove,
997 	.driver = {
998 		.name	= KBUILD_MODNAME,
999 		.of_match_table = of_match_ptr(dw_dma_of_id_table),
1000 		.pm = &dw_axi_dma_pm_ops,
1001 	},
1002 };
1003 module_platform_driver(dw_driver);
1004 
1005 MODULE_LICENSE("GPL v2");
1006 MODULE_DESCRIPTION("Synopsys DesignWare AXI DMA Controller platform driver");
1007 MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>");
1008