xref: /linux/drivers/dma/img-mdc-dma.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IMG Multi-threaded DMA Controller (MDC)
4  *
5  * Copyright (C) 2009,2012,2013 Imagination Technologies Ltd.
6  * Copyright (C) 2014 Google, Inc.
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/dmaengine.h>
12 #include <linux/dmapool.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/kernel.h>
17 #include <linux/mfd/syscon.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_dma.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/regmap.h>
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 
27 #include "dmaengine.h"
28 #include "virt-dma.h"
29 
30 #define MDC_MAX_DMA_CHANNELS			32
31 
32 #define MDC_GENERAL_CONFIG			0x000
33 #define MDC_GENERAL_CONFIG_LIST_IEN		BIT(31)
34 #define MDC_GENERAL_CONFIG_IEN			BIT(29)
35 #define MDC_GENERAL_CONFIG_LEVEL_INT		BIT(28)
36 #define MDC_GENERAL_CONFIG_INC_W		BIT(12)
37 #define MDC_GENERAL_CONFIG_INC_R		BIT(8)
38 #define MDC_GENERAL_CONFIG_PHYSICAL_W		BIT(7)
39 #define MDC_GENERAL_CONFIG_WIDTH_W_SHIFT	4
40 #define MDC_GENERAL_CONFIG_WIDTH_W_MASK		0x7
41 #define MDC_GENERAL_CONFIG_PHYSICAL_R		BIT(3)
42 #define MDC_GENERAL_CONFIG_WIDTH_R_SHIFT	0
43 #define MDC_GENERAL_CONFIG_WIDTH_R_MASK		0x7
44 
45 #define MDC_READ_PORT_CONFIG			0x004
46 #define MDC_READ_PORT_CONFIG_STHREAD_SHIFT	28
47 #define MDC_READ_PORT_CONFIG_STHREAD_MASK	0xf
48 #define MDC_READ_PORT_CONFIG_RTHREAD_SHIFT	24
49 #define MDC_READ_PORT_CONFIG_RTHREAD_MASK	0xf
50 #define MDC_READ_PORT_CONFIG_WTHREAD_SHIFT	16
51 #define MDC_READ_PORT_CONFIG_WTHREAD_MASK	0xf
52 #define MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT	4
53 #define MDC_READ_PORT_CONFIG_BURST_SIZE_MASK	0xff
54 #define MDC_READ_PORT_CONFIG_DREQ_ENABLE	BIT(1)
55 
56 #define MDC_READ_ADDRESS			0x008
57 
58 #define MDC_WRITE_ADDRESS			0x00c
59 
60 #define MDC_TRANSFER_SIZE			0x010
61 #define MDC_TRANSFER_SIZE_MASK			0xffffff
62 
63 #define MDC_LIST_NODE_ADDRESS			0x014
64 
65 #define MDC_CMDS_PROCESSED			0x018
66 #define MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT	16
67 #define MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK	0x3f
68 #define MDC_CMDS_PROCESSED_INT_ACTIVE		BIT(8)
69 #define MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT	0
70 #define MDC_CMDS_PROCESSED_CMDS_DONE_MASK	0x3f
71 
72 #define MDC_CONTROL_AND_STATUS			0x01c
73 #define MDC_CONTROL_AND_STATUS_CANCEL		BIT(20)
74 #define MDC_CONTROL_AND_STATUS_LIST_EN		BIT(4)
75 #define MDC_CONTROL_AND_STATUS_EN		BIT(0)
76 
77 #define MDC_ACTIVE_TRANSFER_SIZE		0x030
78 
79 #define MDC_GLOBAL_CONFIG_A				0x900
80 #define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT	16
81 #define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK	0xff
82 #define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT		8
83 #define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK		0xff
84 #define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT		0
85 #define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK		0xff
86 
87 struct mdc_hw_list_desc {
88 	u32 gen_conf;
89 	u32 readport_conf;
90 	u32 read_addr;
91 	u32 write_addr;
92 	u32 xfer_size;
93 	u32 node_addr;
94 	u32 cmds_done;
95 	u32 ctrl_status;
96 	/*
97 	 * Not part of the list descriptor, but instead used by the CPU to
98 	 * traverse the list.
99 	 */
100 	struct mdc_hw_list_desc *next_desc;
101 };
102 
103 struct mdc_tx_desc {
104 	struct mdc_chan *chan;
105 	struct virt_dma_desc vd;
106 	dma_addr_t list_phys;
107 	struct mdc_hw_list_desc *list;
108 	bool cyclic;
109 	bool cmd_loaded;
110 	unsigned int list_len;
111 	unsigned int list_period_len;
112 	size_t list_xfer_size;
113 	unsigned int list_cmds_done;
114 };
115 
116 struct mdc_chan {
117 	struct mdc_dma *mdma;
118 	struct virt_dma_chan vc;
119 	struct dma_slave_config config;
120 	struct mdc_tx_desc *desc;
121 	int irq;
122 	unsigned int periph;
123 	unsigned int thread;
124 	unsigned int chan_nr;
125 };
126 
127 struct mdc_dma_soc_data {
128 	void (*enable_chan)(struct mdc_chan *mchan);
129 	void (*disable_chan)(struct mdc_chan *mchan);
130 };
131 
132 struct mdc_dma {
133 	struct dma_device dma_dev;
134 	void __iomem *regs;
135 	struct clk *clk;
136 	struct dma_pool *desc_pool;
137 	struct regmap *periph_regs;
138 	spinlock_t lock;
139 	unsigned int nr_threads;
140 	unsigned int nr_channels;
141 	unsigned int bus_width;
142 	unsigned int max_burst_mult;
143 	unsigned int max_xfer_size;
144 	const struct mdc_dma_soc_data *soc;
145 	struct mdc_chan channels[MDC_MAX_DMA_CHANNELS];
146 };
147 
148 static inline u32 mdc_readl(struct mdc_dma *mdma, u32 reg)
149 {
150 	return readl(mdma->regs + reg);
151 }
152 
153 static inline void mdc_writel(struct mdc_dma *mdma, u32 val, u32 reg)
154 {
155 	writel(val, mdma->regs + reg);
156 }
157 
158 static inline u32 mdc_chan_readl(struct mdc_chan *mchan, u32 reg)
159 {
160 	return mdc_readl(mchan->mdma, mchan->chan_nr * 0x040 + reg);
161 }
162 
163 static inline void mdc_chan_writel(struct mdc_chan *mchan, u32 val, u32 reg)
164 {
165 	mdc_writel(mchan->mdma, val, mchan->chan_nr * 0x040 + reg);
166 }
167 
168 static inline struct mdc_chan *to_mdc_chan(struct dma_chan *c)
169 {
170 	return container_of(to_virt_chan(c), struct mdc_chan, vc);
171 }
172 
173 static inline struct mdc_tx_desc *to_mdc_desc(struct dma_async_tx_descriptor *t)
174 {
175 	struct virt_dma_desc *vdesc = container_of(t, struct virt_dma_desc, tx);
176 
177 	return container_of(vdesc, struct mdc_tx_desc, vd);
178 }
179 
180 static inline struct device *mdma2dev(struct mdc_dma *mdma)
181 {
182 	return mdma->dma_dev.dev;
183 }
184 
185 static inline unsigned int to_mdc_width(unsigned int bytes)
186 {
187 	return ffs(bytes) - 1;
188 }
189 
190 static inline void mdc_set_read_width(struct mdc_hw_list_desc *ldesc,
191 				      unsigned int bytes)
192 {
193 	ldesc->gen_conf |= to_mdc_width(bytes) <<
194 		MDC_GENERAL_CONFIG_WIDTH_R_SHIFT;
195 }
196 
197 static inline void mdc_set_write_width(struct mdc_hw_list_desc *ldesc,
198 				       unsigned int bytes)
199 {
200 	ldesc->gen_conf |= to_mdc_width(bytes) <<
201 		MDC_GENERAL_CONFIG_WIDTH_W_SHIFT;
202 }
203 
204 static void mdc_list_desc_config(struct mdc_chan *mchan,
205 				 struct mdc_hw_list_desc *ldesc,
206 				 enum dma_transfer_direction dir,
207 				 dma_addr_t src, dma_addr_t dst, size_t len)
208 {
209 	struct mdc_dma *mdma = mchan->mdma;
210 	unsigned int max_burst, burst_size;
211 
212 	ldesc->gen_conf = MDC_GENERAL_CONFIG_IEN | MDC_GENERAL_CONFIG_LIST_IEN |
213 		MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
214 		MDC_GENERAL_CONFIG_PHYSICAL_R;
215 	ldesc->readport_conf =
216 		(mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
217 		(mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
218 		(mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
219 	ldesc->read_addr = src;
220 	ldesc->write_addr = dst;
221 	ldesc->xfer_size = len - 1;
222 	ldesc->node_addr = 0;
223 	ldesc->cmds_done = 0;
224 	ldesc->ctrl_status = MDC_CONTROL_AND_STATUS_LIST_EN |
225 		MDC_CONTROL_AND_STATUS_EN;
226 	ldesc->next_desc = NULL;
227 
228 	if (IS_ALIGNED(dst, mdma->bus_width) &&
229 	    IS_ALIGNED(src, mdma->bus_width))
230 		max_burst = mdma->bus_width * mdma->max_burst_mult;
231 	else
232 		max_burst = mdma->bus_width * (mdma->max_burst_mult - 1);
233 
234 	if (dir == DMA_MEM_TO_DEV) {
235 		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R;
236 		ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
237 		mdc_set_read_width(ldesc, mdma->bus_width);
238 		mdc_set_write_width(ldesc, mchan->config.dst_addr_width);
239 		burst_size = min(max_burst, mchan->config.dst_maxburst *
240 				 mchan->config.dst_addr_width);
241 	} else if (dir == DMA_DEV_TO_MEM) {
242 		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_W;
243 		ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
244 		mdc_set_read_width(ldesc, mchan->config.src_addr_width);
245 		mdc_set_write_width(ldesc, mdma->bus_width);
246 		burst_size = min(max_burst, mchan->config.src_maxburst *
247 				 mchan->config.src_addr_width);
248 	} else {
249 		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R |
250 			MDC_GENERAL_CONFIG_INC_W;
251 		mdc_set_read_width(ldesc, mdma->bus_width);
252 		mdc_set_write_width(ldesc, mdma->bus_width);
253 		burst_size = max_burst;
254 	}
255 	ldesc->readport_conf |= (burst_size - 1) <<
256 		MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT;
257 }
258 
259 static void mdc_list_desc_free(struct mdc_tx_desc *mdesc)
260 {
261 	struct mdc_dma *mdma = mdesc->chan->mdma;
262 	struct mdc_hw_list_desc *curr, *next;
263 	dma_addr_t curr_phys, next_phys;
264 
265 	curr = mdesc->list;
266 	curr_phys = mdesc->list_phys;
267 	while (curr) {
268 		next = curr->next_desc;
269 		next_phys = curr->node_addr;
270 		dma_pool_free(mdma->desc_pool, curr, curr_phys);
271 		curr = next;
272 		curr_phys = next_phys;
273 	}
274 }
275 
276 static void mdc_desc_free(struct virt_dma_desc *vd)
277 {
278 	struct mdc_tx_desc *mdesc = to_mdc_desc(&vd->tx);
279 
280 	mdc_list_desc_free(mdesc);
281 	kfree(mdesc);
282 }
283 
284 static struct dma_async_tx_descriptor *mdc_prep_dma_memcpy(
285 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len,
286 	unsigned long flags)
287 {
288 	struct mdc_chan *mchan = to_mdc_chan(chan);
289 	struct mdc_dma *mdma = mchan->mdma;
290 	struct mdc_tx_desc *mdesc;
291 	struct mdc_hw_list_desc *curr, *prev = NULL;
292 	dma_addr_t curr_phys;
293 
294 	if (!len)
295 		return NULL;
296 
297 	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
298 	if (!mdesc)
299 		return NULL;
300 	mdesc->chan = mchan;
301 	mdesc->list_xfer_size = len;
302 
303 	while (len > 0) {
304 		size_t xfer_size;
305 
306 		curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT, &curr_phys);
307 		if (!curr)
308 			goto free_desc;
309 
310 		if (prev) {
311 			prev->node_addr = curr_phys;
312 			prev->next_desc = curr;
313 		} else {
314 			mdesc->list_phys = curr_phys;
315 			mdesc->list = curr;
316 		}
317 
318 		xfer_size = min_t(size_t, mdma->max_xfer_size, len);
319 
320 		mdc_list_desc_config(mchan, curr, DMA_MEM_TO_MEM, src, dest,
321 				     xfer_size);
322 
323 		prev = curr;
324 
325 		mdesc->list_len++;
326 		src += xfer_size;
327 		dest += xfer_size;
328 		len -= xfer_size;
329 	}
330 
331 	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
332 
333 free_desc:
334 	mdc_desc_free(&mdesc->vd);
335 
336 	return NULL;
337 }
338 
339 static int mdc_check_slave_width(struct mdc_chan *mchan,
340 				 enum dma_transfer_direction dir)
341 {
342 	enum dma_slave_buswidth width;
343 
344 	if (dir == DMA_MEM_TO_DEV)
345 		width = mchan->config.dst_addr_width;
346 	else
347 		width = mchan->config.src_addr_width;
348 
349 	switch (width) {
350 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
351 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
352 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
353 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
354 		break;
355 	default:
356 		return -EINVAL;
357 	}
358 
359 	if (width > mchan->mdma->bus_width)
360 		return -EINVAL;
361 
362 	return 0;
363 }
364 
365 static struct dma_async_tx_descriptor *mdc_prep_dma_cyclic(
366 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
367 	size_t period_len, enum dma_transfer_direction dir,
368 	unsigned long flags)
369 {
370 	struct mdc_chan *mchan = to_mdc_chan(chan);
371 	struct mdc_dma *mdma = mchan->mdma;
372 	struct mdc_tx_desc *mdesc;
373 	struct mdc_hw_list_desc *curr, *prev = NULL;
374 	dma_addr_t curr_phys;
375 
376 	if (!buf_len && !period_len)
377 		return NULL;
378 
379 	if (!is_slave_direction(dir))
380 		return NULL;
381 
382 	if (mdc_check_slave_width(mchan, dir) < 0)
383 		return NULL;
384 
385 	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
386 	if (!mdesc)
387 		return NULL;
388 	mdesc->chan = mchan;
389 	mdesc->cyclic = true;
390 	mdesc->list_xfer_size = buf_len;
391 	mdesc->list_period_len = DIV_ROUND_UP(period_len,
392 					      mdma->max_xfer_size);
393 
394 	while (buf_len > 0) {
395 		size_t remainder = min(period_len, buf_len);
396 
397 		while (remainder > 0) {
398 			size_t xfer_size;
399 
400 			curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
401 					      &curr_phys);
402 			if (!curr)
403 				goto free_desc;
404 
405 			if (!prev) {
406 				mdesc->list_phys = curr_phys;
407 				mdesc->list = curr;
408 			} else {
409 				prev->node_addr = curr_phys;
410 				prev->next_desc = curr;
411 			}
412 
413 			xfer_size = min_t(size_t, mdma->max_xfer_size,
414 					  remainder);
415 
416 			if (dir == DMA_MEM_TO_DEV) {
417 				mdc_list_desc_config(mchan, curr, dir,
418 						     buf_addr,
419 						     mchan->config.dst_addr,
420 						     xfer_size);
421 			} else {
422 				mdc_list_desc_config(mchan, curr, dir,
423 						     mchan->config.src_addr,
424 						     buf_addr,
425 						     xfer_size);
426 			}
427 
428 			prev = curr;
429 
430 			mdesc->list_len++;
431 			buf_addr += xfer_size;
432 			buf_len -= xfer_size;
433 			remainder -= xfer_size;
434 		}
435 	}
436 	prev->node_addr = mdesc->list_phys;
437 
438 	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
439 
440 free_desc:
441 	mdc_desc_free(&mdesc->vd);
442 
443 	return NULL;
444 }
445 
446 static struct dma_async_tx_descriptor *mdc_prep_slave_sg(
447 	struct dma_chan *chan, struct scatterlist *sgl,
448 	unsigned int sg_len, enum dma_transfer_direction dir,
449 	unsigned long flags, void *context)
450 {
451 	struct mdc_chan *mchan = to_mdc_chan(chan);
452 	struct mdc_dma *mdma = mchan->mdma;
453 	struct mdc_tx_desc *mdesc;
454 	struct scatterlist *sg;
455 	struct mdc_hw_list_desc *curr, *prev = NULL;
456 	dma_addr_t curr_phys;
457 	unsigned int i;
458 
459 	if (!sgl)
460 		return NULL;
461 
462 	if (!is_slave_direction(dir))
463 		return NULL;
464 
465 	if (mdc_check_slave_width(mchan, dir) < 0)
466 		return NULL;
467 
468 	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
469 	if (!mdesc)
470 		return NULL;
471 	mdesc->chan = mchan;
472 
473 	for_each_sg(sgl, sg, sg_len, i) {
474 		dma_addr_t buf = sg_dma_address(sg);
475 		size_t buf_len = sg_dma_len(sg);
476 
477 		while (buf_len > 0) {
478 			size_t xfer_size;
479 
480 			curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
481 					      &curr_phys);
482 			if (!curr)
483 				goto free_desc;
484 
485 			if (!prev) {
486 				mdesc->list_phys = curr_phys;
487 				mdesc->list = curr;
488 			} else {
489 				prev->node_addr = curr_phys;
490 				prev->next_desc = curr;
491 			}
492 
493 			xfer_size = min_t(size_t, mdma->max_xfer_size,
494 					  buf_len);
495 
496 			if (dir == DMA_MEM_TO_DEV) {
497 				mdc_list_desc_config(mchan, curr, dir, buf,
498 						     mchan->config.dst_addr,
499 						     xfer_size);
500 			} else {
501 				mdc_list_desc_config(mchan, curr, dir,
502 						     mchan->config.src_addr,
503 						     buf, xfer_size);
504 			}
505 
506 			prev = curr;
507 
508 			mdesc->list_len++;
509 			mdesc->list_xfer_size += xfer_size;
510 			buf += xfer_size;
511 			buf_len -= xfer_size;
512 		}
513 	}
514 
515 	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
516 
517 free_desc:
518 	mdc_desc_free(&mdesc->vd);
519 
520 	return NULL;
521 }
522 
523 static void mdc_issue_desc(struct mdc_chan *mchan)
524 {
525 	struct mdc_dma *mdma = mchan->mdma;
526 	struct virt_dma_desc *vd;
527 	struct mdc_tx_desc *mdesc;
528 	u32 val;
529 
530 	vd = vchan_next_desc(&mchan->vc);
531 	if (!vd)
532 		return;
533 
534 	list_del(&vd->node);
535 
536 	mdesc = to_mdc_desc(&vd->tx);
537 	mchan->desc = mdesc;
538 
539 	dev_dbg(mdma2dev(mdma), "Issuing descriptor on channel %d\n",
540 		mchan->chan_nr);
541 
542 	mdma->soc->enable_chan(mchan);
543 
544 	val = mdc_chan_readl(mchan, MDC_GENERAL_CONFIG);
545 	val |= MDC_GENERAL_CONFIG_LIST_IEN | MDC_GENERAL_CONFIG_IEN |
546 		MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
547 		MDC_GENERAL_CONFIG_PHYSICAL_R;
548 	mdc_chan_writel(mchan, val, MDC_GENERAL_CONFIG);
549 	val = (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
550 		(mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
551 		(mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
552 	mdc_chan_writel(mchan, val, MDC_READ_PORT_CONFIG);
553 	mdc_chan_writel(mchan, mdesc->list_phys, MDC_LIST_NODE_ADDRESS);
554 	val = mdc_chan_readl(mchan, MDC_CONTROL_AND_STATUS);
555 	val |= MDC_CONTROL_AND_STATUS_LIST_EN;
556 	mdc_chan_writel(mchan, val, MDC_CONTROL_AND_STATUS);
557 }
558 
559 static void mdc_issue_pending(struct dma_chan *chan)
560 {
561 	struct mdc_chan *mchan = to_mdc_chan(chan);
562 	unsigned long flags;
563 
564 	spin_lock_irqsave(&mchan->vc.lock, flags);
565 	if (vchan_issue_pending(&mchan->vc) && !mchan->desc)
566 		mdc_issue_desc(mchan);
567 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
568 }
569 
570 static enum dma_status mdc_tx_status(struct dma_chan *chan,
571 	dma_cookie_t cookie, struct dma_tx_state *txstate)
572 {
573 	struct mdc_chan *mchan = to_mdc_chan(chan);
574 	struct mdc_tx_desc *mdesc;
575 	struct virt_dma_desc *vd;
576 	unsigned long flags;
577 	size_t bytes = 0;
578 	int ret;
579 
580 	ret = dma_cookie_status(chan, cookie, txstate);
581 	if (ret == DMA_COMPLETE)
582 		return ret;
583 
584 	if (!txstate)
585 		return ret;
586 
587 	spin_lock_irqsave(&mchan->vc.lock, flags);
588 	vd = vchan_find_desc(&mchan->vc, cookie);
589 	if (vd) {
590 		mdesc = to_mdc_desc(&vd->tx);
591 		bytes = mdesc->list_xfer_size;
592 	} else if (mchan->desc && mchan->desc->vd.tx.cookie == cookie) {
593 		struct mdc_hw_list_desc *ldesc;
594 		u32 val1, val2, done, processed, residue;
595 		int i, cmds;
596 
597 		mdesc = mchan->desc;
598 
599 		/*
600 		 * Determine the number of commands that haven't been
601 		 * processed (handled by the IRQ handler) yet.
602 		 */
603 		do {
604 			val1 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
605 				~MDC_CMDS_PROCESSED_INT_ACTIVE;
606 			residue = mdc_chan_readl(mchan,
607 						 MDC_ACTIVE_TRANSFER_SIZE);
608 			val2 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
609 				~MDC_CMDS_PROCESSED_INT_ACTIVE;
610 		} while (val1 != val2);
611 
612 		done = (val1 >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
613 			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
614 		processed = (val1 >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
615 			MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
616 		cmds = (done - processed) %
617 			(MDC_CMDS_PROCESSED_CMDS_DONE_MASK + 1);
618 
619 		/*
620 		 * If the command loaded event hasn't been processed yet, then
621 		 * the difference above includes an extra command.
622 		 */
623 		if (!mdesc->cmd_loaded)
624 			cmds--;
625 		else
626 			cmds += mdesc->list_cmds_done;
627 
628 		bytes = mdesc->list_xfer_size;
629 		ldesc = mdesc->list;
630 		for (i = 0; i < cmds; i++) {
631 			bytes -= ldesc->xfer_size + 1;
632 			ldesc = ldesc->next_desc;
633 		}
634 		if (ldesc) {
635 			if (residue != MDC_TRANSFER_SIZE_MASK)
636 				bytes -= ldesc->xfer_size - residue;
637 			else
638 				bytes -= ldesc->xfer_size + 1;
639 		}
640 	}
641 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
642 
643 	dma_set_residue(txstate, bytes);
644 
645 	return ret;
646 }
647 
648 static unsigned int mdc_get_new_events(struct mdc_chan *mchan)
649 {
650 	u32 val, processed, done1, done2;
651 	unsigned int ret;
652 
653 	val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
654 	processed = (val >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
655 				MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
656 	/*
657 	 * CMDS_DONE may have incremented between reading CMDS_PROCESSED
658 	 * and clearing INT_ACTIVE.  Re-read CMDS_PROCESSED to ensure we
659 	 * didn't miss a command completion.
660 	 */
661 	do {
662 		val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
663 
664 		done1 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
665 			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
666 
667 		val &= ~((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK <<
668 			  MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) |
669 			 MDC_CMDS_PROCESSED_INT_ACTIVE);
670 
671 		val |= done1 << MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT;
672 
673 		mdc_chan_writel(mchan, val, MDC_CMDS_PROCESSED);
674 
675 		val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
676 
677 		done2 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
678 			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
679 	} while (done1 != done2);
680 
681 	if (done1 >= processed)
682 		ret = done1 - processed;
683 	else
684 		ret = ((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK + 1) -
685 			processed) + done1;
686 
687 	return ret;
688 }
689 
690 static int mdc_terminate_all(struct dma_chan *chan)
691 {
692 	struct mdc_chan *mchan = to_mdc_chan(chan);
693 	unsigned long flags;
694 	LIST_HEAD(head);
695 
696 	spin_lock_irqsave(&mchan->vc.lock, flags);
697 
698 	mdc_chan_writel(mchan, MDC_CONTROL_AND_STATUS_CANCEL,
699 			MDC_CONTROL_AND_STATUS);
700 
701 	if (mchan->desc) {
702 		vchan_terminate_vdesc(&mchan->desc->vd);
703 		mchan->desc = NULL;
704 	}
705 	vchan_get_all_descriptors(&mchan->vc, &head);
706 
707 	mdc_get_new_events(mchan);
708 
709 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
710 
711 	vchan_dma_desc_free_list(&mchan->vc, &head);
712 
713 	return 0;
714 }
715 
716 static void mdc_synchronize(struct dma_chan *chan)
717 {
718 	struct mdc_chan *mchan = to_mdc_chan(chan);
719 
720 	vchan_synchronize(&mchan->vc);
721 }
722 
723 static int mdc_slave_config(struct dma_chan *chan,
724 			    struct dma_slave_config *config)
725 {
726 	struct mdc_chan *mchan = to_mdc_chan(chan);
727 	unsigned long flags;
728 
729 	spin_lock_irqsave(&mchan->vc.lock, flags);
730 	mchan->config = *config;
731 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
732 
733 	return 0;
734 }
735 
736 static int mdc_alloc_chan_resources(struct dma_chan *chan)
737 {
738 	struct mdc_chan *mchan = to_mdc_chan(chan);
739 	struct device *dev = mdma2dev(mchan->mdma);
740 
741 	return pm_runtime_get_sync(dev);
742 }
743 
744 static void mdc_free_chan_resources(struct dma_chan *chan)
745 {
746 	struct mdc_chan *mchan = to_mdc_chan(chan);
747 	struct mdc_dma *mdma = mchan->mdma;
748 	struct device *dev = mdma2dev(mdma);
749 
750 	mdc_terminate_all(chan);
751 	mdma->soc->disable_chan(mchan);
752 	pm_runtime_put(dev);
753 }
754 
755 static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
756 {
757 	struct mdc_chan *mchan = (struct mdc_chan *)dev_id;
758 	struct mdc_tx_desc *mdesc;
759 	unsigned int i, new_events;
760 
761 	spin_lock(&mchan->vc.lock);
762 
763 	dev_dbg(mdma2dev(mchan->mdma), "IRQ on channel %d\n", mchan->chan_nr);
764 
765 	new_events = mdc_get_new_events(mchan);
766 
767 	if (!new_events)
768 		goto out;
769 
770 	mdesc = mchan->desc;
771 	if (!mdesc) {
772 		dev_warn(mdma2dev(mchan->mdma),
773 			 "IRQ with no active descriptor on channel %d\n",
774 			 mchan->chan_nr);
775 		goto out;
776 	}
777 
778 	for (i = 0; i < new_events; i++) {
779 		/*
780 		 * The first interrupt in a transfer indicates that the
781 		 * command list has been loaded, not that a command has
782 		 * been completed.
783 		 */
784 		if (!mdesc->cmd_loaded) {
785 			mdesc->cmd_loaded = true;
786 			continue;
787 		}
788 
789 		mdesc->list_cmds_done++;
790 		if (mdesc->cyclic) {
791 			mdesc->list_cmds_done %= mdesc->list_len;
792 			if (mdesc->list_cmds_done % mdesc->list_period_len == 0)
793 				vchan_cyclic_callback(&mdesc->vd);
794 		} else if (mdesc->list_cmds_done == mdesc->list_len) {
795 			mchan->desc = NULL;
796 			vchan_cookie_complete(&mdesc->vd);
797 			mdc_issue_desc(mchan);
798 			break;
799 		}
800 	}
801 out:
802 	spin_unlock(&mchan->vc.lock);
803 
804 	return IRQ_HANDLED;
805 }
806 
807 static struct dma_chan *mdc_of_xlate(struct of_phandle_args *dma_spec,
808 				     struct of_dma *ofdma)
809 {
810 	struct mdc_dma *mdma = ofdma->of_dma_data;
811 	struct dma_chan *chan;
812 
813 	if (dma_spec->args_count != 3)
814 		return NULL;
815 
816 	list_for_each_entry(chan, &mdma->dma_dev.channels, device_node) {
817 		struct mdc_chan *mchan = to_mdc_chan(chan);
818 
819 		if (!(dma_spec->args[1] & BIT(mchan->chan_nr)))
820 			continue;
821 		if (dma_get_slave_channel(chan)) {
822 			mchan->periph = dma_spec->args[0];
823 			mchan->thread = dma_spec->args[2];
824 			return chan;
825 		}
826 	}
827 
828 	return NULL;
829 }
830 
831 #define PISTACHIO_CR_PERIPH_DMA_ROUTE(ch)	(0x120 + 0x4 * ((ch) / 4))
832 #define PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(ch) (8 * ((ch) % 4))
833 #define PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK	0x3f
834 
835 static void pistachio_mdc_enable_chan(struct mdc_chan *mchan)
836 {
837 	struct mdc_dma *mdma = mchan->mdma;
838 
839 	regmap_update_bits(mdma->periph_regs,
840 			   PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
841 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
842 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
843 			   mchan->periph <<
844 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr));
845 }
846 
847 static void pistachio_mdc_disable_chan(struct mdc_chan *mchan)
848 {
849 	struct mdc_dma *mdma = mchan->mdma;
850 
851 	regmap_update_bits(mdma->periph_regs,
852 			   PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
853 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
854 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
855 			   0);
856 }
857 
858 static const struct mdc_dma_soc_data pistachio_mdc_data = {
859 	.enable_chan = pistachio_mdc_enable_chan,
860 	.disable_chan = pistachio_mdc_disable_chan,
861 };
862 
863 static const struct of_device_id mdc_dma_of_match[] = {
864 	{ .compatible = "img,pistachio-mdc-dma", .data = &pistachio_mdc_data, },
865 	{ },
866 };
867 MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
868 
869 static int img_mdc_runtime_suspend(struct device *dev)
870 {
871 	struct mdc_dma *mdma = dev_get_drvdata(dev);
872 
873 	clk_disable_unprepare(mdma->clk);
874 
875 	return 0;
876 }
877 
878 static int img_mdc_runtime_resume(struct device *dev)
879 {
880 	struct mdc_dma *mdma = dev_get_drvdata(dev);
881 
882 	return clk_prepare_enable(mdma->clk);
883 }
884 
885 static int mdc_dma_probe(struct platform_device *pdev)
886 {
887 	struct mdc_dma *mdma;
888 	unsigned int i;
889 	u32 val;
890 	int ret;
891 
892 	mdma = devm_kzalloc(&pdev->dev, sizeof(*mdma), GFP_KERNEL);
893 	if (!mdma)
894 		return -ENOMEM;
895 	platform_set_drvdata(pdev, mdma);
896 
897 	mdma->soc = of_device_get_match_data(&pdev->dev);
898 
899 	mdma->regs = devm_platform_ioremap_resource(pdev, 0);
900 	if (IS_ERR(mdma->regs))
901 		return PTR_ERR(mdma->regs);
902 
903 	mdma->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
904 							    "img,cr-periph");
905 	if (IS_ERR(mdma->periph_regs))
906 		return PTR_ERR(mdma->periph_regs);
907 
908 	mdma->clk = devm_clk_get(&pdev->dev, "sys");
909 	if (IS_ERR(mdma->clk))
910 		return PTR_ERR(mdma->clk);
911 
912 	dma_cap_zero(mdma->dma_dev.cap_mask);
913 	dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
914 	dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
915 	dma_cap_set(DMA_CYCLIC, mdma->dma_dev.cap_mask);
916 	dma_cap_set(DMA_MEMCPY, mdma->dma_dev.cap_mask);
917 
918 	val = mdc_readl(mdma, MDC_GLOBAL_CONFIG_A);
919 	mdma->nr_channels = (val >> MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT) &
920 		MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK;
921 	mdma->nr_threads =
922 		1 << ((val >> MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT) &
923 		      MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK);
924 	mdma->bus_width =
925 		(1 << ((val >> MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT) &
926 		       MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK)) / 8;
927 	/*
928 	 * Although transfer sizes of up to MDC_TRANSFER_SIZE_MASK + 1 bytes
929 	 * are supported, this makes it possible for the value reported in
930 	 * MDC_ACTIVE_TRANSFER_SIZE to be ambiguous - an active transfer size
931 	 * of MDC_TRANSFER_SIZE_MASK may indicate either that 0 bytes or
932 	 * MDC_TRANSFER_SIZE_MASK + 1 bytes are remaining.  To eliminate this
933 	 * ambiguity, restrict transfer sizes to one bus-width less than the
934 	 * actual maximum.
935 	 */
936 	mdma->max_xfer_size = MDC_TRANSFER_SIZE_MASK + 1 - mdma->bus_width;
937 
938 	of_property_read_u32(pdev->dev.of_node, "dma-channels",
939 			     &mdma->nr_channels);
940 	ret = of_property_read_u32(pdev->dev.of_node,
941 				   "img,max-burst-multiplier",
942 				   &mdma->max_burst_mult);
943 	if (ret)
944 		return ret;
945 
946 	mdma->dma_dev.dev = &pdev->dev;
947 	mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
948 	mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
949 	mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
950 	mdma->dma_dev.device_alloc_chan_resources = mdc_alloc_chan_resources;
951 	mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
952 	mdma->dma_dev.device_tx_status = mdc_tx_status;
953 	mdma->dma_dev.device_issue_pending = mdc_issue_pending;
954 	mdma->dma_dev.device_terminate_all = mdc_terminate_all;
955 	mdma->dma_dev.device_synchronize = mdc_synchronize;
956 	mdma->dma_dev.device_config = mdc_slave_config;
957 
958 	mdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
959 	mdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
960 	for (i = 1; i <= mdma->bus_width; i <<= 1) {
961 		mdma->dma_dev.src_addr_widths |= BIT(i);
962 		mdma->dma_dev.dst_addr_widths |= BIT(i);
963 	}
964 
965 	INIT_LIST_HEAD(&mdma->dma_dev.channels);
966 	for (i = 0; i < mdma->nr_channels; i++) {
967 		struct mdc_chan *mchan = &mdma->channels[i];
968 
969 		mchan->mdma = mdma;
970 		mchan->chan_nr = i;
971 		mchan->irq = platform_get_irq(pdev, i);
972 		if (mchan->irq < 0)
973 			return mchan->irq;
974 
975 		ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
976 				       IRQ_TYPE_LEVEL_HIGH,
977 				       dev_name(&pdev->dev), mchan);
978 		if (ret < 0)
979 			return ret;
980 
981 		mchan->vc.desc_free = mdc_desc_free;
982 		vchan_init(&mchan->vc, &mdma->dma_dev);
983 	}
984 
985 	mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
986 					   sizeof(struct mdc_hw_list_desc),
987 					   4, 0);
988 	if (!mdma->desc_pool)
989 		return -ENOMEM;
990 
991 	pm_runtime_enable(&pdev->dev);
992 	if (!pm_runtime_enabled(&pdev->dev)) {
993 		ret = img_mdc_runtime_resume(&pdev->dev);
994 		if (ret)
995 			return ret;
996 	}
997 
998 	ret = dma_async_device_register(&mdma->dma_dev);
999 	if (ret)
1000 		goto suspend;
1001 
1002 	ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
1003 	if (ret)
1004 		goto unregister;
1005 
1006 	dev_info(&pdev->dev, "MDC with %u channels and %u threads\n",
1007 		 mdma->nr_channels, mdma->nr_threads);
1008 
1009 	return 0;
1010 
1011 unregister:
1012 	dma_async_device_unregister(&mdma->dma_dev);
1013 suspend:
1014 	if (!pm_runtime_enabled(&pdev->dev))
1015 		img_mdc_runtime_suspend(&pdev->dev);
1016 	pm_runtime_disable(&pdev->dev);
1017 	return ret;
1018 }
1019 
1020 static void mdc_dma_remove(struct platform_device *pdev)
1021 {
1022 	struct mdc_dma *mdma = platform_get_drvdata(pdev);
1023 	struct mdc_chan *mchan, *next;
1024 
1025 	of_dma_controller_free(pdev->dev.of_node);
1026 	dma_async_device_unregister(&mdma->dma_dev);
1027 
1028 	list_for_each_entry_safe(mchan, next, &mdma->dma_dev.channels,
1029 				 vc.chan.device_node) {
1030 		list_del(&mchan->vc.chan.device_node);
1031 
1032 		devm_free_irq(&pdev->dev, mchan->irq, mchan);
1033 
1034 		tasklet_kill(&mchan->vc.task);
1035 	}
1036 
1037 	pm_runtime_disable(&pdev->dev);
1038 	if (!pm_runtime_status_suspended(&pdev->dev))
1039 		img_mdc_runtime_suspend(&pdev->dev);
1040 }
1041 
1042 #ifdef CONFIG_PM_SLEEP
1043 static int img_mdc_suspend_late(struct device *dev)
1044 {
1045 	struct mdc_dma *mdma = dev_get_drvdata(dev);
1046 	int i;
1047 
1048 	/* Check that all channels are idle */
1049 	for (i = 0; i < mdma->nr_channels; i++) {
1050 		struct mdc_chan *mchan = &mdma->channels[i];
1051 
1052 		if (unlikely(mchan->desc))
1053 			return -EBUSY;
1054 	}
1055 
1056 	return pm_runtime_force_suspend(dev);
1057 }
1058 
1059 static int img_mdc_resume_early(struct device *dev)
1060 {
1061 	return pm_runtime_force_resume(dev);
1062 }
1063 #endif /* CONFIG_PM_SLEEP */
1064 
1065 static const struct dev_pm_ops img_mdc_pm_ops = {
1066 	SET_RUNTIME_PM_OPS(img_mdc_runtime_suspend,
1067 			   img_mdc_runtime_resume, NULL)
1068 	SET_LATE_SYSTEM_SLEEP_PM_OPS(img_mdc_suspend_late,
1069 				     img_mdc_resume_early)
1070 };
1071 
1072 static struct platform_driver mdc_dma_driver = {
1073 	.driver = {
1074 		.name = "img-mdc-dma",
1075 		.pm = &img_mdc_pm_ops,
1076 		.of_match_table = of_match_ptr(mdc_dma_of_match),
1077 	},
1078 	.probe = mdc_dma_probe,
1079 	.remove = mdc_dma_remove,
1080 };
1081 module_platform_driver(mdc_dma_driver);
1082 
1083 MODULE_DESCRIPTION("IMG Multi-threaded DMA Controller (MDC) driver");
1084 MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
1085 MODULE_LICENSE("GPL v2");
1086