xref: /linux/drivers/dma/img-mdc-dma.c (revision b0f84a84fff180718995b1269da2988e5b28be42)
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_device.h>
21 #include <linux/of_dma.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/regmap.h>
25 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27 
28 #include "dmaengine.h"
29 #include "virt-dma.h"
30 
31 #define MDC_MAX_DMA_CHANNELS			32
32 
33 #define MDC_GENERAL_CONFIG			0x000
34 #define MDC_GENERAL_CONFIG_LIST_IEN		BIT(31)
35 #define MDC_GENERAL_CONFIG_IEN			BIT(29)
36 #define MDC_GENERAL_CONFIG_LEVEL_INT		BIT(28)
37 #define MDC_GENERAL_CONFIG_INC_W		BIT(12)
38 #define MDC_GENERAL_CONFIG_INC_R		BIT(8)
39 #define MDC_GENERAL_CONFIG_PHYSICAL_W		BIT(7)
40 #define MDC_GENERAL_CONFIG_WIDTH_W_SHIFT	4
41 #define MDC_GENERAL_CONFIG_WIDTH_W_MASK		0x7
42 #define MDC_GENERAL_CONFIG_PHYSICAL_R		BIT(3)
43 #define MDC_GENERAL_CONFIG_WIDTH_R_SHIFT	0
44 #define MDC_GENERAL_CONFIG_WIDTH_R_MASK		0x7
45 
46 #define MDC_READ_PORT_CONFIG			0x004
47 #define MDC_READ_PORT_CONFIG_STHREAD_SHIFT	28
48 #define MDC_READ_PORT_CONFIG_STHREAD_MASK	0xf
49 #define MDC_READ_PORT_CONFIG_RTHREAD_SHIFT	24
50 #define MDC_READ_PORT_CONFIG_RTHREAD_MASK	0xf
51 #define MDC_READ_PORT_CONFIG_WTHREAD_SHIFT	16
52 #define MDC_READ_PORT_CONFIG_WTHREAD_MASK	0xf
53 #define MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT	4
54 #define MDC_READ_PORT_CONFIG_BURST_SIZE_MASK	0xff
55 #define MDC_READ_PORT_CONFIG_DREQ_ENABLE	BIT(1)
56 
57 #define MDC_READ_ADDRESS			0x008
58 
59 #define MDC_WRITE_ADDRESS			0x00c
60 
61 #define MDC_TRANSFER_SIZE			0x010
62 #define MDC_TRANSFER_SIZE_MASK			0xffffff
63 
64 #define MDC_LIST_NODE_ADDRESS			0x014
65 
66 #define MDC_CMDS_PROCESSED			0x018
67 #define MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT	16
68 #define MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK	0x3f
69 #define MDC_CMDS_PROCESSED_INT_ACTIVE		BIT(8)
70 #define MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT	0
71 #define MDC_CMDS_PROCESSED_CMDS_DONE_MASK	0x3f
72 
73 #define MDC_CONTROL_AND_STATUS			0x01c
74 #define MDC_CONTROL_AND_STATUS_CANCEL		BIT(20)
75 #define MDC_CONTROL_AND_STATUS_LIST_EN		BIT(4)
76 #define MDC_CONTROL_AND_STATUS_EN		BIT(0)
77 
78 #define MDC_ACTIVE_TRANSFER_SIZE		0x030
79 
80 #define MDC_GLOBAL_CONFIG_A				0x900
81 #define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT	16
82 #define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK	0xff
83 #define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT		8
84 #define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK		0xff
85 #define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT		0
86 #define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK		0xff
87 
88 struct mdc_hw_list_desc {
89 	u32 gen_conf;
90 	u32 readport_conf;
91 	u32 read_addr;
92 	u32 write_addr;
93 	u32 xfer_size;
94 	u32 node_addr;
95 	u32 cmds_done;
96 	u32 ctrl_status;
97 	/*
98 	 * Not part of the list descriptor, but instead used by the CPU to
99 	 * traverse the list.
100 	 */
101 	struct mdc_hw_list_desc *next_desc;
102 };
103 
104 struct mdc_tx_desc {
105 	struct mdc_chan *chan;
106 	struct virt_dma_desc vd;
107 	dma_addr_t list_phys;
108 	struct mdc_hw_list_desc *list;
109 	bool cyclic;
110 	bool cmd_loaded;
111 	unsigned int list_len;
112 	unsigned int list_period_len;
113 	size_t list_xfer_size;
114 	unsigned int list_cmds_done;
115 };
116 
117 struct mdc_chan {
118 	struct mdc_dma *mdma;
119 	struct virt_dma_chan vc;
120 	struct dma_slave_config config;
121 	struct mdc_tx_desc *desc;
122 	int irq;
123 	unsigned int periph;
124 	unsigned int thread;
125 	unsigned int chan_nr;
126 };
127 
128 struct mdc_dma_soc_data {
129 	void (*enable_chan)(struct mdc_chan *mchan);
130 	void (*disable_chan)(struct mdc_chan *mchan);
131 };
132 
133 struct mdc_dma {
134 	struct dma_device dma_dev;
135 	void __iomem *regs;
136 	struct clk *clk;
137 	struct dma_pool *desc_pool;
138 	struct regmap *periph_regs;
139 	spinlock_t lock;
140 	unsigned int nr_threads;
141 	unsigned int nr_channels;
142 	unsigned int bus_width;
143 	unsigned int max_burst_mult;
144 	unsigned int max_xfer_size;
145 	const struct mdc_dma_soc_data *soc;
146 	struct mdc_chan channels[MDC_MAX_DMA_CHANNELS];
147 };
148 
149 static inline u32 mdc_readl(struct mdc_dma *mdma, u32 reg)
150 {
151 	return readl(mdma->regs + reg);
152 }
153 
154 static inline void mdc_writel(struct mdc_dma *mdma, u32 val, u32 reg)
155 {
156 	writel(val, mdma->regs + reg);
157 }
158 
159 static inline u32 mdc_chan_readl(struct mdc_chan *mchan, u32 reg)
160 {
161 	return mdc_readl(mchan->mdma, mchan->chan_nr * 0x040 + reg);
162 }
163 
164 static inline void mdc_chan_writel(struct mdc_chan *mchan, u32 val, u32 reg)
165 {
166 	mdc_writel(mchan->mdma, val, mchan->chan_nr * 0x040 + reg);
167 }
168 
169 static inline struct mdc_chan *to_mdc_chan(struct dma_chan *c)
170 {
171 	return container_of(to_virt_chan(c), struct mdc_chan, vc);
172 }
173 
174 static inline struct mdc_tx_desc *to_mdc_desc(struct dma_async_tx_descriptor *t)
175 {
176 	struct virt_dma_desc *vdesc = container_of(t, struct virt_dma_desc, tx);
177 
178 	return container_of(vdesc, struct mdc_tx_desc, vd);
179 }
180 
181 static inline struct device *mdma2dev(struct mdc_dma *mdma)
182 {
183 	return mdma->dma_dev.dev;
184 }
185 
186 static inline unsigned int to_mdc_width(unsigned int bytes)
187 {
188 	return ffs(bytes) - 1;
189 }
190 
191 static inline void mdc_set_read_width(struct mdc_hw_list_desc *ldesc,
192 				      unsigned int bytes)
193 {
194 	ldesc->gen_conf |= to_mdc_width(bytes) <<
195 		MDC_GENERAL_CONFIG_WIDTH_R_SHIFT;
196 }
197 
198 static inline void mdc_set_write_width(struct mdc_hw_list_desc *ldesc,
199 				       unsigned int bytes)
200 {
201 	ldesc->gen_conf |= to_mdc_width(bytes) <<
202 		MDC_GENERAL_CONFIG_WIDTH_W_SHIFT;
203 }
204 
205 static void mdc_list_desc_config(struct mdc_chan *mchan,
206 				 struct mdc_hw_list_desc *ldesc,
207 				 enum dma_transfer_direction dir,
208 				 dma_addr_t src, dma_addr_t dst, size_t len)
209 {
210 	struct mdc_dma *mdma = mchan->mdma;
211 	unsigned int max_burst, burst_size;
212 
213 	ldesc->gen_conf = MDC_GENERAL_CONFIG_IEN | MDC_GENERAL_CONFIG_LIST_IEN |
214 		MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
215 		MDC_GENERAL_CONFIG_PHYSICAL_R;
216 	ldesc->readport_conf =
217 		(mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
218 		(mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
219 		(mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
220 	ldesc->read_addr = src;
221 	ldesc->write_addr = dst;
222 	ldesc->xfer_size = len - 1;
223 	ldesc->node_addr = 0;
224 	ldesc->cmds_done = 0;
225 	ldesc->ctrl_status = MDC_CONTROL_AND_STATUS_LIST_EN |
226 		MDC_CONTROL_AND_STATUS_EN;
227 	ldesc->next_desc = NULL;
228 
229 	if (IS_ALIGNED(dst, mdma->bus_width) &&
230 	    IS_ALIGNED(src, mdma->bus_width))
231 		max_burst = mdma->bus_width * mdma->max_burst_mult;
232 	else
233 		max_burst = mdma->bus_width * (mdma->max_burst_mult - 1);
234 
235 	if (dir == DMA_MEM_TO_DEV) {
236 		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R;
237 		ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
238 		mdc_set_read_width(ldesc, mdma->bus_width);
239 		mdc_set_write_width(ldesc, mchan->config.dst_addr_width);
240 		burst_size = min(max_burst, mchan->config.dst_maxburst *
241 				 mchan->config.dst_addr_width);
242 	} else if (dir == DMA_DEV_TO_MEM) {
243 		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_W;
244 		ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
245 		mdc_set_read_width(ldesc, mchan->config.src_addr_width);
246 		mdc_set_write_width(ldesc, mdma->bus_width);
247 		burst_size = min(max_burst, mchan->config.src_maxburst *
248 				 mchan->config.src_addr_width);
249 	} else {
250 		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R |
251 			MDC_GENERAL_CONFIG_INC_W;
252 		mdc_set_read_width(ldesc, mdma->bus_width);
253 		mdc_set_write_width(ldesc, mdma->bus_width);
254 		burst_size = max_burst;
255 	}
256 	ldesc->readport_conf |= (burst_size - 1) <<
257 		MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT;
258 }
259 
260 static void mdc_list_desc_free(struct mdc_tx_desc *mdesc)
261 {
262 	struct mdc_dma *mdma = mdesc->chan->mdma;
263 	struct mdc_hw_list_desc *curr, *next;
264 	dma_addr_t curr_phys, next_phys;
265 
266 	curr = mdesc->list;
267 	curr_phys = mdesc->list_phys;
268 	while (curr) {
269 		next = curr->next_desc;
270 		next_phys = curr->node_addr;
271 		dma_pool_free(mdma->desc_pool, curr, curr_phys);
272 		curr = next;
273 		curr_phys = next_phys;
274 	}
275 }
276 
277 static void mdc_desc_free(struct virt_dma_desc *vd)
278 {
279 	struct mdc_tx_desc *mdesc = to_mdc_desc(&vd->tx);
280 
281 	mdc_list_desc_free(mdesc);
282 	kfree(mdesc);
283 }
284 
285 static struct dma_async_tx_descriptor *mdc_prep_dma_memcpy(
286 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len,
287 	unsigned long flags)
288 {
289 	struct mdc_chan *mchan = to_mdc_chan(chan);
290 	struct mdc_dma *mdma = mchan->mdma;
291 	struct mdc_tx_desc *mdesc;
292 	struct mdc_hw_list_desc *curr, *prev = NULL;
293 	dma_addr_t curr_phys;
294 
295 	if (!len)
296 		return NULL;
297 
298 	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
299 	if (!mdesc)
300 		return NULL;
301 	mdesc->chan = mchan;
302 	mdesc->list_xfer_size = len;
303 
304 	while (len > 0) {
305 		size_t xfer_size;
306 
307 		curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT, &curr_phys);
308 		if (!curr)
309 			goto free_desc;
310 
311 		if (prev) {
312 			prev->node_addr = curr_phys;
313 			prev->next_desc = curr;
314 		} else {
315 			mdesc->list_phys = curr_phys;
316 			mdesc->list = curr;
317 		}
318 
319 		xfer_size = min_t(size_t, mdma->max_xfer_size, len);
320 
321 		mdc_list_desc_config(mchan, curr, DMA_MEM_TO_MEM, src, dest,
322 				     xfer_size);
323 
324 		prev = curr;
325 
326 		mdesc->list_len++;
327 		src += xfer_size;
328 		dest += xfer_size;
329 		len -= xfer_size;
330 	}
331 
332 	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
333 
334 free_desc:
335 	mdc_desc_free(&mdesc->vd);
336 
337 	return NULL;
338 }
339 
340 static int mdc_check_slave_width(struct mdc_chan *mchan,
341 				 enum dma_transfer_direction dir)
342 {
343 	enum dma_slave_buswidth width;
344 
345 	if (dir == DMA_MEM_TO_DEV)
346 		width = mchan->config.dst_addr_width;
347 	else
348 		width = mchan->config.src_addr_width;
349 
350 	switch (width) {
351 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
352 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
353 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
354 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
355 		break;
356 	default:
357 		return -EINVAL;
358 	}
359 
360 	if (width > mchan->mdma->bus_width)
361 		return -EINVAL;
362 
363 	return 0;
364 }
365 
366 static struct dma_async_tx_descriptor *mdc_prep_dma_cyclic(
367 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
368 	size_t period_len, enum dma_transfer_direction dir,
369 	unsigned long flags)
370 {
371 	struct mdc_chan *mchan = to_mdc_chan(chan);
372 	struct mdc_dma *mdma = mchan->mdma;
373 	struct mdc_tx_desc *mdesc;
374 	struct mdc_hw_list_desc *curr, *prev = NULL;
375 	dma_addr_t curr_phys;
376 
377 	if (!buf_len && !period_len)
378 		return NULL;
379 
380 	if (!is_slave_direction(dir))
381 		return NULL;
382 
383 	if (mdc_check_slave_width(mchan, dir) < 0)
384 		return NULL;
385 
386 	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
387 	if (!mdesc)
388 		return NULL;
389 	mdesc->chan = mchan;
390 	mdesc->cyclic = true;
391 	mdesc->list_xfer_size = buf_len;
392 	mdesc->list_period_len = DIV_ROUND_UP(period_len,
393 					      mdma->max_xfer_size);
394 
395 	while (buf_len > 0) {
396 		size_t remainder = min(period_len, buf_len);
397 
398 		while (remainder > 0) {
399 			size_t xfer_size;
400 
401 			curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
402 					      &curr_phys);
403 			if (!curr)
404 				goto free_desc;
405 
406 			if (!prev) {
407 				mdesc->list_phys = curr_phys;
408 				mdesc->list = curr;
409 			} else {
410 				prev->node_addr = curr_phys;
411 				prev->next_desc = curr;
412 			}
413 
414 			xfer_size = min_t(size_t, mdma->max_xfer_size,
415 					  remainder);
416 
417 			if (dir == DMA_MEM_TO_DEV) {
418 				mdc_list_desc_config(mchan, curr, dir,
419 						     buf_addr,
420 						     mchan->config.dst_addr,
421 						     xfer_size);
422 			} else {
423 				mdc_list_desc_config(mchan, curr, dir,
424 						     mchan->config.src_addr,
425 						     buf_addr,
426 						     xfer_size);
427 			}
428 
429 			prev = curr;
430 
431 			mdesc->list_len++;
432 			buf_addr += xfer_size;
433 			buf_len -= xfer_size;
434 			remainder -= xfer_size;
435 		}
436 	}
437 	prev->node_addr = mdesc->list_phys;
438 
439 	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
440 
441 free_desc:
442 	mdc_desc_free(&mdesc->vd);
443 
444 	return NULL;
445 }
446 
447 static struct dma_async_tx_descriptor *mdc_prep_slave_sg(
448 	struct dma_chan *chan, struct scatterlist *sgl,
449 	unsigned int sg_len, enum dma_transfer_direction dir,
450 	unsigned long flags, void *context)
451 {
452 	struct mdc_chan *mchan = to_mdc_chan(chan);
453 	struct mdc_dma *mdma = mchan->mdma;
454 	struct mdc_tx_desc *mdesc;
455 	struct scatterlist *sg;
456 	struct mdc_hw_list_desc *curr, *prev = NULL;
457 	dma_addr_t curr_phys;
458 	unsigned int i;
459 
460 	if (!sgl)
461 		return NULL;
462 
463 	if (!is_slave_direction(dir))
464 		return NULL;
465 
466 	if (mdc_check_slave_width(mchan, dir) < 0)
467 		return NULL;
468 
469 	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
470 	if (!mdesc)
471 		return NULL;
472 	mdesc->chan = mchan;
473 
474 	for_each_sg(sgl, sg, sg_len, i) {
475 		dma_addr_t buf = sg_dma_address(sg);
476 		size_t buf_len = sg_dma_len(sg);
477 
478 		while (buf_len > 0) {
479 			size_t xfer_size;
480 
481 			curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
482 					      &curr_phys);
483 			if (!curr)
484 				goto free_desc;
485 
486 			if (!prev) {
487 				mdesc->list_phys = curr_phys;
488 				mdesc->list = curr;
489 			} else {
490 				prev->node_addr = curr_phys;
491 				prev->next_desc = curr;
492 			}
493 
494 			xfer_size = min_t(size_t, mdma->max_xfer_size,
495 					  buf_len);
496 
497 			if (dir == DMA_MEM_TO_DEV) {
498 				mdc_list_desc_config(mchan, curr, dir, buf,
499 						     mchan->config.dst_addr,
500 						     xfer_size);
501 			} else {
502 				mdc_list_desc_config(mchan, curr, dir,
503 						     mchan->config.src_addr,
504 						     buf, xfer_size);
505 			}
506 
507 			prev = curr;
508 
509 			mdesc->list_len++;
510 			mdesc->list_xfer_size += xfer_size;
511 			buf += xfer_size;
512 			buf_len -= xfer_size;
513 		}
514 	}
515 
516 	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
517 
518 free_desc:
519 	mdc_desc_free(&mdesc->vd);
520 
521 	return NULL;
522 }
523 
524 static void mdc_issue_desc(struct mdc_chan *mchan)
525 {
526 	struct mdc_dma *mdma = mchan->mdma;
527 	struct virt_dma_desc *vd;
528 	struct mdc_tx_desc *mdesc;
529 	u32 val;
530 
531 	vd = vchan_next_desc(&mchan->vc);
532 	if (!vd)
533 		return;
534 
535 	list_del(&vd->node);
536 
537 	mdesc = to_mdc_desc(&vd->tx);
538 	mchan->desc = mdesc;
539 
540 	dev_dbg(mdma2dev(mdma), "Issuing descriptor on channel %d\n",
541 		mchan->chan_nr);
542 
543 	mdma->soc->enable_chan(mchan);
544 
545 	val = mdc_chan_readl(mchan, MDC_GENERAL_CONFIG);
546 	val |= MDC_GENERAL_CONFIG_LIST_IEN | MDC_GENERAL_CONFIG_IEN |
547 		MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
548 		MDC_GENERAL_CONFIG_PHYSICAL_R;
549 	mdc_chan_writel(mchan, val, MDC_GENERAL_CONFIG);
550 	val = (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
551 		(mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
552 		(mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
553 	mdc_chan_writel(mchan, val, MDC_READ_PORT_CONFIG);
554 	mdc_chan_writel(mchan, mdesc->list_phys, MDC_LIST_NODE_ADDRESS);
555 	val = mdc_chan_readl(mchan, MDC_CONTROL_AND_STATUS);
556 	val |= MDC_CONTROL_AND_STATUS_LIST_EN;
557 	mdc_chan_writel(mchan, val, MDC_CONTROL_AND_STATUS);
558 }
559 
560 static void mdc_issue_pending(struct dma_chan *chan)
561 {
562 	struct mdc_chan *mchan = to_mdc_chan(chan);
563 	unsigned long flags;
564 
565 	spin_lock_irqsave(&mchan->vc.lock, flags);
566 	if (vchan_issue_pending(&mchan->vc) && !mchan->desc)
567 		mdc_issue_desc(mchan);
568 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
569 }
570 
571 static enum dma_status mdc_tx_status(struct dma_chan *chan,
572 	dma_cookie_t cookie, struct dma_tx_state *txstate)
573 {
574 	struct mdc_chan *mchan = to_mdc_chan(chan);
575 	struct mdc_tx_desc *mdesc;
576 	struct virt_dma_desc *vd;
577 	unsigned long flags;
578 	size_t bytes = 0;
579 	int ret;
580 
581 	ret = dma_cookie_status(chan, cookie, txstate);
582 	if (ret == DMA_COMPLETE)
583 		return ret;
584 
585 	if (!txstate)
586 		return ret;
587 
588 	spin_lock_irqsave(&mchan->vc.lock, flags);
589 	vd = vchan_find_desc(&mchan->vc, cookie);
590 	if (vd) {
591 		mdesc = to_mdc_desc(&vd->tx);
592 		bytes = mdesc->list_xfer_size;
593 	} else if (mchan->desc && mchan->desc->vd.tx.cookie == cookie) {
594 		struct mdc_hw_list_desc *ldesc;
595 		u32 val1, val2, done, processed, residue;
596 		int i, cmds;
597 
598 		mdesc = mchan->desc;
599 
600 		/*
601 		 * Determine the number of commands that haven't been
602 		 * processed (handled by the IRQ handler) yet.
603 		 */
604 		do {
605 			val1 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
606 				~MDC_CMDS_PROCESSED_INT_ACTIVE;
607 			residue = mdc_chan_readl(mchan,
608 						 MDC_ACTIVE_TRANSFER_SIZE);
609 			val2 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
610 				~MDC_CMDS_PROCESSED_INT_ACTIVE;
611 		} while (val1 != val2);
612 
613 		done = (val1 >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
614 			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
615 		processed = (val1 >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
616 			MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
617 		cmds = (done - processed) %
618 			(MDC_CMDS_PROCESSED_CMDS_DONE_MASK + 1);
619 
620 		/*
621 		 * If the command loaded event hasn't been processed yet, then
622 		 * the difference above includes an extra command.
623 		 */
624 		if (!mdesc->cmd_loaded)
625 			cmds--;
626 		else
627 			cmds += mdesc->list_cmds_done;
628 
629 		bytes = mdesc->list_xfer_size;
630 		ldesc = mdesc->list;
631 		for (i = 0; i < cmds; i++) {
632 			bytes -= ldesc->xfer_size + 1;
633 			ldesc = ldesc->next_desc;
634 		}
635 		if (ldesc) {
636 			if (residue != MDC_TRANSFER_SIZE_MASK)
637 				bytes -= ldesc->xfer_size - residue;
638 			else
639 				bytes -= ldesc->xfer_size + 1;
640 		}
641 	}
642 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
643 
644 	dma_set_residue(txstate, bytes);
645 
646 	return ret;
647 }
648 
649 static unsigned int mdc_get_new_events(struct mdc_chan *mchan)
650 {
651 	u32 val, processed, done1, done2;
652 	unsigned int ret;
653 
654 	val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
655 	processed = (val >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
656 				MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
657 	/*
658 	 * CMDS_DONE may have incremented between reading CMDS_PROCESSED
659 	 * and clearing INT_ACTIVE.  Re-read CMDS_PROCESSED to ensure we
660 	 * didn't miss a command completion.
661 	 */
662 	do {
663 		val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
664 
665 		done1 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
666 			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
667 
668 		val &= ~((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK <<
669 			  MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) |
670 			 MDC_CMDS_PROCESSED_INT_ACTIVE);
671 
672 		val |= done1 << MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT;
673 
674 		mdc_chan_writel(mchan, val, MDC_CMDS_PROCESSED);
675 
676 		val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
677 
678 		done2 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
679 			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
680 	} while (done1 != done2);
681 
682 	if (done1 >= processed)
683 		ret = done1 - processed;
684 	else
685 		ret = ((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK + 1) -
686 			processed) + done1;
687 
688 	return ret;
689 }
690 
691 static int mdc_terminate_all(struct dma_chan *chan)
692 {
693 	struct mdc_chan *mchan = to_mdc_chan(chan);
694 	unsigned long flags;
695 	LIST_HEAD(head);
696 
697 	spin_lock_irqsave(&mchan->vc.lock, flags);
698 
699 	mdc_chan_writel(mchan, MDC_CONTROL_AND_STATUS_CANCEL,
700 			MDC_CONTROL_AND_STATUS);
701 
702 	if (mchan->desc) {
703 		vchan_terminate_vdesc(&mchan->desc->vd);
704 		mchan->desc = NULL;
705 	}
706 	vchan_get_all_descriptors(&mchan->vc, &head);
707 
708 	mdc_get_new_events(mchan);
709 
710 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
711 
712 	vchan_dma_desc_free_list(&mchan->vc, &head);
713 
714 	return 0;
715 }
716 
717 static void mdc_synchronize(struct dma_chan *chan)
718 {
719 	struct mdc_chan *mchan = to_mdc_chan(chan);
720 
721 	vchan_synchronize(&mchan->vc);
722 }
723 
724 static int mdc_slave_config(struct dma_chan *chan,
725 			    struct dma_slave_config *config)
726 {
727 	struct mdc_chan *mchan = to_mdc_chan(chan);
728 	unsigned long flags;
729 
730 	spin_lock_irqsave(&mchan->vc.lock, flags);
731 	mchan->config = *config;
732 	spin_unlock_irqrestore(&mchan->vc.lock, flags);
733 
734 	return 0;
735 }
736 
737 static int mdc_alloc_chan_resources(struct dma_chan *chan)
738 {
739 	struct mdc_chan *mchan = to_mdc_chan(chan);
740 	struct device *dev = mdma2dev(mchan->mdma);
741 
742 	return pm_runtime_get_sync(dev);
743 }
744 
745 static void mdc_free_chan_resources(struct dma_chan *chan)
746 {
747 	struct mdc_chan *mchan = to_mdc_chan(chan);
748 	struct mdc_dma *mdma = mchan->mdma;
749 	struct device *dev = mdma2dev(mdma);
750 
751 	mdc_terminate_all(chan);
752 	mdma->soc->disable_chan(mchan);
753 	pm_runtime_put(dev);
754 }
755 
756 static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
757 {
758 	struct mdc_chan *mchan = (struct mdc_chan *)dev_id;
759 	struct mdc_tx_desc *mdesc;
760 	unsigned int i, new_events;
761 
762 	spin_lock(&mchan->vc.lock);
763 
764 	dev_dbg(mdma2dev(mchan->mdma), "IRQ on channel %d\n", mchan->chan_nr);
765 
766 	new_events = mdc_get_new_events(mchan);
767 
768 	if (!new_events)
769 		goto out;
770 
771 	mdesc = mchan->desc;
772 	if (!mdesc) {
773 		dev_warn(mdma2dev(mchan->mdma),
774 			 "IRQ with no active descriptor on channel %d\n",
775 			 mchan->chan_nr);
776 		goto out;
777 	}
778 
779 	for (i = 0; i < new_events; i++) {
780 		/*
781 		 * The first interrupt in a transfer indicates that the
782 		 * command list has been loaded, not that a command has
783 		 * been completed.
784 		 */
785 		if (!mdesc->cmd_loaded) {
786 			mdesc->cmd_loaded = true;
787 			continue;
788 		}
789 
790 		mdesc->list_cmds_done++;
791 		if (mdesc->cyclic) {
792 			mdesc->list_cmds_done %= mdesc->list_len;
793 			if (mdesc->list_cmds_done % mdesc->list_period_len == 0)
794 				vchan_cyclic_callback(&mdesc->vd);
795 		} else if (mdesc->list_cmds_done == mdesc->list_len) {
796 			mchan->desc = NULL;
797 			vchan_cookie_complete(&mdesc->vd);
798 			mdc_issue_desc(mchan);
799 			break;
800 		}
801 	}
802 out:
803 	spin_unlock(&mchan->vc.lock);
804 
805 	return IRQ_HANDLED;
806 }
807 
808 static struct dma_chan *mdc_of_xlate(struct of_phandle_args *dma_spec,
809 				     struct of_dma *ofdma)
810 {
811 	struct mdc_dma *mdma = ofdma->of_dma_data;
812 	struct dma_chan *chan;
813 
814 	if (dma_spec->args_count != 3)
815 		return NULL;
816 
817 	list_for_each_entry(chan, &mdma->dma_dev.channels, device_node) {
818 		struct mdc_chan *mchan = to_mdc_chan(chan);
819 
820 		if (!(dma_spec->args[1] & BIT(mchan->chan_nr)))
821 			continue;
822 		if (dma_get_slave_channel(chan)) {
823 			mchan->periph = dma_spec->args[0];
824 			mchan->thread = dma_spec->args[2];
825 			return chan;
826 		}
827 	}
828 
829 	return NULL;
830 }
831 
832 #define PISTACHIO_CR_PERIPH_DMA_ROUTE(ch)	(0x120 + 0x4 * ((ch) / 4))
833 #define PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(ch) (8 * ((ch) % 4))
834 #define PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK	0x3f
835 
836 static void pistachio_mdc_enable_chan(struct mdc_chan *mchan)
837 {
838 	struct mdc_dma *mdma = mchan->mdma;
839 
840 	regmap_update_bits(mdma->periph_regs,
841 			   PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
842 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
843 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
844 			   mchan->periph <<
845 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr));
846 }
847 
848 static void pistachio_mdc_disable_chan(struct mdc_chan *mchan)
849 {
850 	struct mdc_dma *mdma = mchan->mdma;
851 
852 	regmap_update_bits(mdma->periph_regs,
853 			   PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
854 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
855 			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
856 			   0);
857 }
858 
859 static const struct mdc_dma_soc_data pistachio_mdc_data = {
860 	.enable_chan = pistachio_mdc_enable_chan,
861 	.disable_chan = pistachio_mdc_disable_chan,
862 };
863 
864 static const struct of_device_id mdc_dma_of_match[] = {
865 	{ .compatible = "img,pistachio-mdc-dma", .data = &pistachio_mdc_data, },
866 	{ },
867 };
868 MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
869 
870 static int img_mdc_runtime_suspend(struct device *dev)
871 {
872 	struct mdc_dma *mdma = dev_get_drvdata(dev);
873 
874 	clk_disable_unprepare(mdma->clk);
875 
876 	return 0;
877 }
878 
879 static int img_mdc_runtime_resume(struct device *dev)
880 {
881 	struct mdc_dma *mdma = dev_get_drvdata(dev);
882 
883 	return clk_prepare_enable(mdma->clk);
884 }
885 
886 static int mdc_dma_probe(struct platform_device *pdev)
887 {
888 	struct mdc_dma *mdma;
889 	struct resource *res;
890 	unsigned int i;
891 	u32 val;
892 	int ret;
893 
894 	mdma = devm_kzalloc(&pdev->dev, sizeof(*mdma), GFP_KERNEL);
895 	if (!mdma)
896 		return -ENOMEM;
897 	platform_set_drvdata(pdev, mdma);
898 
899 	mdma->soc = of_device_get_match_data(&pdev->dev);
900 
901 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
902 	mdma->regs = devm_ioremap_resource(&pdev->dev, res);
903 	if (IS_ERR(mdma->regs))
904 		return PTR_ERR(mdma->regs);
905 
906 	mdma->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
907 							    "img,cr-periph");
908 	if (IS_ERR(mdma->periph_regs))
909 		return PTR_ERR(mdma->periph_regs);
910 
911 	mdma->clk = devm_clk_get(&pdev->dev, "sys");
912 	if (IS_ERR(mdma->clk))
913 		return PTR_ERR(mdma->clk);
914 
915 	dma_cap_zero(mdma->dma_dev.cap_mask);
916 	dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
917 	dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
918 	dma_cap_set(DMA_CYCLIC, mdma->dma_dev.cap_mask);
919 	dma_cap_set(DMA_MEMCPY, mdma->dma_dev.cap_mask);
920 
921 	val = mdc_readl(mdma, MDC_GLOBAL_CONFIG_A);
922 	mdma->nr_channels = (val >> MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT) &
923 		MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK;
924 	mdma->nr_threads =
925 		1 << ((val >> MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT) &
926 		      MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK);
927 	mdma->bus_width =
928 		(1 << ((val >> MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT) &
929 		       MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK)) / 8;
930 	/*
931 	 * Although transfer sizes of up to MDC_TRANSFER_SIZE_MASK + 1 bytes
932 	 * are supported, this makes it possible for the value reported in
933 	 * MDC_ACTIVE_TRANSFER_SIZE to be ambiguous - an active transfer size
934 	 * of MDC_TRANSFER_SIZE_MASK may indicate either that 0 bytes or
935 	 * MDC_TRANSFER_SIZE_MASK + 1 bytes are remaining.  To eliminate this
936 	 * ambiguity, restrict transfer sizes to one bus-width less than the
937 	 * actual maximum.
938 	 */
939 	mdma->max_xfer_size = MDC_TRANSFER_SIZE_MASK + 1 - mdma->bus_width;
940 
941 	of_property_read_u32(pdev->dev.of_node, "dma-channels",
942 			     &mdma->nr_channels);
943 	ret = of_property_read_u32(pdev->dev.of_node,
944 				   "img,max-burst-multiplier",
945 				   &mdma->max_burst_mult);
946 	if (ret)
947 		return ret;
948 
949 	mdma->dma_dev.dev = &pdev->dev;
950 	mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
951 	mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
952 	mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
953 	mdma->dma_dev.device_alloc_chan_resources = mdc_alloc_chan_resources;
954 	mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
955 	mdma->dma_dev.device_tx_status = mdc_tx_status;
956 	mdma->dma_dev.device_issue_pending = mdc_issue_pending;
957 	mdma->dma_dev.device_terminate_all = mdc_terminate_all;
958 	mdma->dma_dev.device_synchronize = mdc_synchronize;
959 	mdma->dma_dev.device_config = mdc_slave_config;
960 
961 	mdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
962 	mdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
963 	for (i = 1; i <= mdma->bus_width; i <<= 1) {
964 		mdma->dma_dev.src_addr_widths |= BIT(i);
965 		mdma->dma_dev.dst_addr_widths |= BIT(i);
966 	}
967 
968 	INIT_LIST_HEAD(&mdma->dma_dev.channels);
969 	for (i = 0; i < mdma->nr_channels; i++) {
970 		struct mdc_chan *mchan = &mdma->channels[i];
971 
972 		mchan->mdma = mdma;
973 		mchan->chan_nr = i;
974 		mchan->irq = platform_get_irq(pdev, i);
975 		if (mchan->irq < 0)
976 			return mchan->irq;
977 
978 		ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
979 				       IRQ_TYPE_LEVEL_HIGH,
980 				       dev_name(&pdev->dev), mchan);
981 		if (ret < 0)
982 			return ret;
983 
984 		mchan->vc.desc_free = mdc_desc_free;
985 		vchan_init(&mchan->vc, &mdma->dma_dev);
986 	}
987 
988 	mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
989 					   sizeof(struct mdc_hw_list_desc),
990 					   4, 0);
991 	if (!mdma->desc_pool)
992 		return -ENOMEM;
993 
994 	pm_runtime_enable(&pdev->dev);
995 	if (!pm_runtime_enabled(&pdev->dev)) {
996 		ret = img_mdc_runtime_resume(&pdev->dev);
997 		if (ret)
998 			return ret;
999 	}
1000 
1001 	ret = dma_async_device_register(&mdma->dma_dev);
1002 	if (ret)
1003 		goto suspend;
1004 
1005 	ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
1006 	if (ret)
1007 		goto unregister;
1008 
1009 	dev_info(&pdev->dev, "MDC with %u channels and %u threads\n",
1010 		 mdma->nr_channels, mdma->nr_threads);
1011 
1012 	return 0;
1013 
1014 unregister:
1015 	dma_async_device_unregister(&mdma->dma_dev);
1016 suspend:
1017 	if (!pm_runtime_enabled(&pdev->dev))
1018 		img_mdc_runtime_suspend(&pdev->dev);
1019 	pm_runtime_disable(&pdev->dev);
1020 	return ret;
1021 }
1022 
1023 static int mdc_dma_remove(struct platform_device *pdev)
1024 {
1025 	struct mdc_dma *mdma = platform_get_drvdata(pdev);
1026 	struct mdc_chan *mchan, *next;
1027 
1028 	of_dma_controller_free(pdev->dev.of_node);
1029 	dma_async_device_unregister(&mdma->dma_dev);
1030 
1031 	list_for_each_entry_safe(mchan, next, &mdma->dma_dev.channels,
1032 				 vc.chan.device_node) {
1033 		list_del(&mchan->vc.chan.device_node);
1034 
1035 		devm_free_irq(&pdev->dev, mchan->irq, mchan);
1036 
1037 		tasklet_kill(&mchan->vc.task);
1038 	}
1039 
1040 	pm_runtime_disable(&pdev->dev);
1041 	if (!pm_runtime_status_suspended(&pdev->dev))
1042 		img_mdc_runtime_suspend(&pdev->dev);
1043 
1044 	return 0;
1045 }
1046 
1047 #ifdef CONFIG_PM_SLEEP
1048 static int img_mdc_suspend_late(struct device *dev)
1049 {
1050 	struct mdc_dma *mdma = dev_get_drvdata(dev);
1051 	int i;
1052 
1053 	/* Check that all channels are idle */
1054 	for (i = 0; i < mdma->nr_channels; i++) {
1055 		struct mdc_chan *mchan = &mdma->channels[i];
1056 
1057 		if (unlikely(mchan->desc))
1058 			return -EBUSY;
1059 	}
1060 
1061 	return pm_runtime_force_suspend(dev);
1062 }
1063 
1064 static int img_mdc_resume_early(struct device *dev)
1065 {
1066 	return pm_runtime_force_resume(dev);
1067 }
1068 #endif /* CONFIG_PM_SLEEP */
1069 
1070 static const struct dev_pm_ops img_mdc_pm_ops = {
1071 	SET_RUNTIME_PM_OPS(img_mdc_runtime_suspend,
1072 			   img_mdc_runtime_resume, NULL)
1073 	SET_LATE_SYSTEM_SLEEP_PM_OPS(img_mdc_suspend_late,
1074 				     img_mdc_resume_early)
1075 };
1076 
1077 static struct platform_driver mdc_dma_driver = {
1078 	.driver = {
1079 		.name = "img-mdc-dma",
1080 		.pm = &img_mdc_pm_ops,
1081 		.of_match_table = of_match_ptr(mdc_dma_of_match),
1082 	},
1083 	.probe = mdc_dma_probe,
1084 	.remove = mdc_dma_remove,
1085 };
1086 module_platform_driver(mdc_dma_driver);
1087 
1088 MODULE_DESCRIPTION("IMG Multi-threaded DMA Controller (MDC) driver");
1089 MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
1090 MODULE_LICENSE("GPL v2");
1091