1 /*
2  * Texas Instruments CPDMA Driver
3  *
4  * Copyright (C) 2010 Texas Instruments
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation version 2.
9  *
10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11  * kind, whether express or implied; without even the implied warranty
12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 #include <linux/kernel.h>
16 #include <linux/spinlock.h>
17 #include <linux/device.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/err.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/io.h>
23 #include <linux/delay.h>
24 #include <linux/genalloc.h>
25 #include "davinci_cpdma.h"
26 
27 /* DMA Registers */
28 #define CPDMA_TXIDVER		0x00
29 #define CPDMA_TXCONTROL		0x04
30 #define CPDMA_TXTEARDOWN	0x08
31 #define CPDMA_RXIDVER		0x10
32 #define CPDMA_RXCONTROL		0x14
33 #define CPDMA_SOFTRESET		0x1c
34 #define CPDMA_RXTEARDOWN	0x18
35 #define CPDMA_TXINTSTATRAW	0x80
36 #define CPDMA_TXINTSTATMASKED	0x84
37 #define CPDMA_TXINTMASKSET	0x88
38 #define CPDMA_TXINTMASKCLEAR	0x8c
39 #define CPDMA_MACINVECTOR	0x90
40 #define CPDMA_MACEOIVECTOR	0x94
41 #define CPDMA_RXINTSTATRAW	0xa0
42 #define CPDMA_RXINTSTATMASKED	0xa4
43 #define CPDMA_RXINTMASKSET	0xa8
44 #define CPDMA_RXINTMASKCLEAR	0xac
45 #define CPDMA_DMAINTSTATRAW	0xb0
46 #define CPDMA_DMAINTSTATMASKED	0xb4
47 #define CPDMA_DMAINTMASKSET	0xb8
48 #define CPDMA_DMAINTMASKCLEAR	0xbc
49 #define CPDMA_DMAINT_HOSTERR	BIT(1)
50 
51 /* the following exist only if has_ext_regs is set */
52 #define CPDMA_DMACONTROL	0x20
53 #define CPDMA_DMASTATUS		0x24
54 #define CPDMA_RXBUFFOFS		0x28
55 #define CPDMA_EM_CONTROL	0x2c
56 
57 /* Descriptor mode bits */
58 #define CPDMA_DESC_SOP		BIT(31)
59 #define CPDMA_DESC_EOP		BIT(30)
60 #define CPDMA_DESC_OWNER	BIT(29)
61 #define CPDMA_DESC_EOQ		BIT(28)
62 #define CPDMA_DESC_TD_COMPLETE	BIT(27)
63 #define CPDMA_DESC_PASS_CRC	BIT(26)
64 #define CPDMA_DESC_TO_PORT_EN	BIT(20)
65 #define CPDMA_TO_PORT_SHIFT	16
66 #define CPDMA_DESC_PORT_MASK	(BIT(18) | BIT(17) | BIT(16))
67 #define CPDMA_DESC_CRC_LEN	4
68 
69 #define CPDMA_TEARDOWN_VALUE	0xfffffffc
70 
71 struct cpdma_desc {
72 	/* hardware fields */
73 	u32			hw_next;
74 	u32			hw_buffer;
75 	u32			hw_len;
76 	u32			hw_mode;
77 	/* software fields */
78 	void			*sw_token;
79 	u32			sw_buffer;
80 	u32			sw_len;
81 };
82 
83 struct cpdma_desc_pool {
84 	phys_addr_t		phys;
85 	dma_addr_t		hw_addr;
86 	void __iomem		*iomap;		/* ioremap map */
87 	void			*cpumap;	/* dma_alloc map */
88 	int			desc_size, mem_size;
89 	int			num_desc, used_desc;
90 	struct device		*dev;
91 	struct gen_pool		*gen_pool;
92 };
93 
94 enum cpdma_state {
95 	CPDMA_STATE_IDLE,
96 	CPDMA_STATE_ACTIVE,
97 	CPDMA_STATE_TEARDOWN,
98 };
99 
100 struct cpdma_ctlr {
101 	enum cpdma_state	state;
102 	struct cpdma_params	params;
103 	struct device		*dev;
104 	struct cpdma_desc_pool	*pool;
105 	spinlock_t		lock;
106 	struct cpdma_chan	*channels[2 * CPDMA_MAX_CHANNELS];
107 };
108 
109 struct cpdma_chan {
110 	struct cpdma_desc __iomem	*head, *tail;
111 	void __iomem			*hdp, *cp, *rxfree;
112 	enum cpdma_state		state;
113 	struct cpdma_ctlr		*ctlr;
114 	int				chan_num;
115 	spinlock_t			lock;
116 	int				count;
117 	u32				desc_num;
118 	u32				mask;
119 	cpdma_handler_fn		handler;
120 	enum dma_data_direction		dir;
121 	struct cpdma_chan_stats		stats;
122 	/* offsets into dmaregs */
123 	int	int_set, int_clear, td;
124 };
125 
126 /* The following make access to common cpdma_ctlr params more readable */
127 #define dmaregs		params.dmaregs
128 #define num_chan	params.num_chan
129 
130 /* various accessors */
131 #define dma_reg_read(ctlr, ofs)		__raw_readl((ctlr)->dmaregs + (ofs))
132 #define chan_read(chan, fld)		__raw_readl((chan)->fld)
133 #define desc_read(desc, fld)		__raw_readl(&(desc)->fld)
134 #define dma_reg_write(ctlr, ofs, v)	__raw_writel(v, (ctlr)->dmaregs + (ofs))
135 #define chan_write(chan, fld, v)	__raw_writel(v, (chan)->fld)
136 #define desc_write(desc, fld, v)	__raw_writel((u32)(v), &(desc)->fld)
137 
138 #define cpdma_desc_to_port(chan, mode, directed)			\
139 	do {								\
140 		if (!is_rx_chan(chan) && ((directed == 1) ||		\
141 					  (directed == 2)))		\
142 			mode |= (CPDMA_DESC_TO_PORT_EN |		\
143 				 (directed << CPDMA_TO_PORT_SHIFT));	\
144 	} while (0)
145 
146 static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
147 {
148 	if (!pool)
149 		return;
150 
151 	WARN_ON(pool->used_desc);
152 	if (pool->cpumap)
153 		dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
154 				  pool->phys);
155 	else
156 		iounmap(pool->iomap);
157 }
158 
159 /*
160  * Utility constructs for a cpdma descriptor pool.  Some devices (e.g. davinci
161  * emac) have dedicated on-chip memory for these descriptors.  Some other
162  * devices (e.g. cpsw switches) use plain old memory.  Descriptor pools
163  * abstract out these details
164  */
165 static struct cpdma_desc_pool *
166 cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr,
167 				int size, int align)
168 {
169 	struct cpdma_desc_pool *pool;
170 	int ret;
171 
172 	pool = devm_kzalloc(dev, sizeof(*pool), GFP_KERNEL);
173 	if (!pool)
174 		goto gen_pool_create_fail;
175 
176 	pool->dev	= dev;
177 	pool->mem_size	= size;
178 	pool->desc_size	= ALIGN(sizeof(struct cpdma_desc), align);
179 	pool->num_desc	= size / pool->desc_size;
180 
181 	pool->gen_pool = devm_gen_pool_create(dev, ilog2(pool->desc_size), -1,
182 					      "cpdma");
183 	if (IS_ERR(pool->gen_pool)) {
184 		dev_err(dev, "pool create failed %ld\n",
185 			PTR_ERR(pool->gen_pool));
186 		goto gen_pool_create_fail;
187 	}
188 
189 	if (phys) {
190 		pool->phys  = phys;
191 		pool->iomap = ioremap(phys, size); /* should be memremap? */
192 		pool->hw_addr = hw_addr;
193 	} else {
194 		pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr,
195 						  GFP_KERNEL);
196 		pool->iomap = (void __iomem __force *)pool->cpumap;
197 		pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
198 	}
199 
200 	if (!pool->iomap)
201 		goto gen_pool_create_fail;
202 
203 	ret = gen_pool_add_virt(pool->gen_pool, (unsigned long)pool->iomap,
204 				pool->phys, pool->mem_size, -1);
205 	if (ret < 0) {
206 		dev_err(dev, "pool add failed %d\n", ret);
207 		goto gen_pool_add_virt_fail;
208 	}
209 
210 	return pool;
211 
212 gen_pool_add_virt_fail:
213 	cpdma_desc_pool_destroy(pool);
214 gen_pool_create_fail:
215 	return NULL;
216 }
217 
218 static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
219 		  struct cpdma_desc __iomem *desc)
220 {
221 	if (!desc)
222 		return 0;
223 	return pool->hw_addr + (__force long)desc - (__force long)pool->iomap;
224 }
225 
226 static inline struct cpdma_desc __iomem *
227 desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
228 {
229 	return dma ? pool->iomap + dma - pool->hw_addr : NULL;
230 }
231 
232 static struct cpdma_desc __iomem *
233 cpdma_desc_alloc(struct cpdma_desc_pool *pool)
234 {
235 	struct cpdma_desc __iomem *desc = NULL;
236 
237 	desc = (struct cpdma_desc __iomem *)gen_pool_alloc(pool->gen_pool,
238 							   pool->desc_size);
239 	if (desc)
240 		pool->used_desc++;
241 
242 	return desc;
243 }
244 
245 static void cpdma_desc_free(struct cpdma_desc_pool *pool,
246 			    struct cpdma_desc __iomem *desc, int num_desc)
247 {
248 	gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size);
249 	pool->used_desc--;
250 }
251 
252 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
253 {
254 	struct cpdma_ctlr *ctlr;
255 
256 	ctlr = devm_kzalloc(params->dev, sizeof(*ctlr), GFP_KERNEL);
257 	if (!ctlr)
258 		return NULL;
259 
260 	ctlr->state = CPDMA_STATE_IDLE;
261 	ctlr->params = *params;
262 	ctlr->dev = params->dev;
263 	spin_lock_init(&ctlr->lock);
264 
265 	ctlr->pool = cpdma_desc_pool_create(ctlr->dev,
266 					    ctlr->params.desc_mem_phys,
267 					    ctlr->params.desc_hw_addr,
268 					    ctlr->params.desc_mem_size,
269 					    ctlr->params.desc_align);
270 	if (!ctlr->pool)
271 		return NULL;
272 
273 	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
274 		ctlr->num_chan = CPDMA_MAX_CHANNELS;
275 	return ctlr;
276 }
277 EXPORT_SYMBOL_GPL(cpdma_ctlr_create);
278 
279 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
280 {
281 	unsigned long flags;
282 	int i;
283 
284 	spin_lock_irqsave(&ctlr->lock, flags);
285 	if (ctlr->state != CPDMA_STATE_IDLE) {
286 		spin_unlock_irqrestore(&ctlr->lock, flags);
287 		return -EBUSY;
288 	}
289 
290 	if (ctlr->params.has_soft_reset) {
291 		unsigned timeout = 10 * 100;
292 
293 		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
294 		while (timeout) {
295 			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
296 				break;
297 			udelay(10);
298 			timeout--;
299 		}
300 		WARN_ON(!timeout);
301 	}
302 
303 	for (i = 0; i < ctlr->num_chan; i++) {
304 		__raw_writel(0, ctlr->params.txhdp + 4 * i);
305 		__raw_writel(0, ctlr->params.rxhdp + 4 * i);
306 		__raw_writel(0, ctlr->params.txcp + 4 * i);
307 		__raw_writel(0, ctlr->params.rxcp + 4 * i);
308 	}
309 
310 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
311 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
312 
313 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
314 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
315 
316 	ctlr->state = CPDMA_STATE_ACTIVE;
317 
318 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
319 		if (ctlr->channels[i])
320 			cpdma_chan_start(ctlr->channels[i]);
321 	}
322 	spin_unlock_irqrestore(&ctlr->lock, flags);
323 	return 0;
324 }
325 EXPORT_SYMBOL_GPL(cpdma_ctlr_start);
326 
327 int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
328 {
329 	unsigned long flags;
330 	int i;
331 
332 	spin_lock_irqsave(&ctlr->lock, flags);
333 	if (ctlr->state == CPDMA_STATE_TEARDOWN) {
334 		spin_unlock_irqrestore(&ctlr->lock, flags);
335 		return -EINVAL;
336 	}
337 
338 	ctlr->state = CPDMA_STATE_TEARDOWN;
339 
340 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
341 		if (ctlr->channels[i])
342 			cpdma_chan_stop(ctlr->channels[i]);
343 	}
344 
345 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
346 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
347 
348 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
349 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
350 
351 	ctlr->state = CPDMA_STATE_IDLE;
352 
353 	spin_unlock_irqrestore(&ctlr->lock, flags);
354 	return 0;
355 }
356 EXPORT_SYMBOL_GPL(cpdma_ctlr_stop);
357 
358 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
359 {
360 	unsigned long flags;
361 	int ret = 0, i;
362 
363 	if (!ctlr)
364 		return -EINVAL;
365 
366 	spin_lock_irqsave(&ctlr->lock, flags);
367 	if (ctlr->state != CPDMA_STATE_IDLE)
368 		cpdma_ctlr_stop(ctlr);
369 
370 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
371 		cpdma_chan_destroy(ctlr->channels[i]);
372 
373 	cpdma_desc_pool_destroy(ctlr->pool);
374 	spin_unlock_irqrestore(&ctlr->lock, flags);
375 	return ret;
376 }
377 EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);
378 
379 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
380 {
381 	unsigned long flags;
382 	int i, reg;
383 
384 	spin_lock_irqsave(&ctlr->lock, flags);
385 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
386 		spin_unlock_irqrestore(&ctlr->lock, flags);
387 		return -EINVAL;
388 	}
389 
390 	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
391 	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
392 
393 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
394 		if (ctlr->channels[i])
395 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
396 	}
397 
398 	spin_unlock_irqrestore(&ctlr->lock, flags);
399 	return 0;
400 }
401 EXPORT_SYMBOL_GPL(cpdma_ctlr_int_ctrl);
402 
403 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
404 {
405 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
406 }
407 EXPORT_SYMBOL_GPL(cpdma_ctlr_eoi);
408 
409 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
410 				     cpdma_handler_fn handler)
411 {
412 	struct cpdma_chan *chan;
413 	int offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
414 	unsigned long flags;
415 
416 	if (__chan_linear(chan_num) >= ctlr->num_chan)
417 		return NULL;
418 
419 	chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
420 	if (!chan)
421 		return ERR_PTR(-ENOMEM);
422 
423 	spin_lock_irqsave(&ctlr->lock, flags);
424 	if (ctlr->channels[chan_num]) {
425 		spin_unlock_irqrestore(&ctlr->lock, flags);
426 		devm_kfree(ctlr->dev, chan);
427 		return ERR_PTR(-EBUSY);
428 	}
429 
430 	chan->ctlr	= ctlr;
431 	chan->state	= CPDMA_STATE_IDLE;
432 	chan->chan_num	= chan_num;
433 	chan->handler	= handler;
434 	chan->desc_num = ctlr->pool->num_desc / 2;
435 
436 	if (is_rx_chan(chan)) {
437 		chan->hdp	= ctlr->params.rxhdp + offset;
438 		chan->cp	= ctlr->params.rxcp + offset;
439 		chan->rxfree	= ctlr->params.rxfree + offset;
440 		chan->int_set	= CPDMA_RXINTMASKSET;
441 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
442 		chan->td	= CPDMA_RXTEARDOWN;
443 		chan->dir	= DMA_FROM_DEVICE;
444 	} else {
445 		chan->hdp	= ctlr->params.txhdp + offset;
446 		chan->cp	= ctlr->params.txcp + offset;
447 		chan->int_set	= CPDMA_TXINTMASKSET;
448 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
449 		chan->td	= CPDMA_TXTEARDOWN;
450 		chan->dir	= DMA_TO_DEVICE;
451 	}
452 	chan->mask = BIT(chan_linear(chan));
453 
454 	spin_lock_init(&chan->lock);
455 
456 	ctlr->channels[chan_num] = chan;
457 	spin_unlock_irqrestore(&ctlr->lock, flags);
458 	return chan;
459 }
460 EXPORT_SYMBOL_GPL(cpdma_chan_create);
461 
462 int cpdma_chan_get_rx_buf_num(struct cpdma_ctlr *ctlr)
463 {
464 	return ctlr->pool->num_desc / 2;
465 }
466 EXPORT_SYMBOL_GPL(cpdma_chan_get_rx_buf_num);
467 
468 int cpdma_chan_destroy(struct cpdma_chan *chan)
469 {
470 	struct cpdma_ctlr *ctlr;
471 	unsigned long flags;
472 
473 	if (!chan)
474 		return -EINVAL;
475 	ctlr = chan->ctlr;
476 
477 	spin_lock_irqsave(&ctlr->lock, flags);
478 	if (chan->state != CPDMA_STATE_IDLE)
479 		cpdma_chan_stop(chan);
480 	ctlr->channels[chan->chan_num] = NULL;
481 	spin_unlock_irqrestore(&ctlr->lock, flags);
482 	return 0;
483 }
484 EXPORT_SYMBOL_GPL(cpdma_chan_destroy);
485 
486 int cpdma_chan_get_stats(struct cpdma_chan *chan,
487 			 struct cpdma_chan_stats *stats)
488 {
489 	unsigned long flags;
490 	if (!chan)
491 		return -EINVAL;
492 	spin_lock_irqsave(&chan->lock, flags);
493 	memcpy(stats, &chan->stats, sizeof(*stats));
494 	spin_unlock_irqrestore(&chan->lock, flags);
495 	return 0;
496 }
497 EXPORT_SYMBOL_GPL(cpdma_chan_get_stats);
498 
499 static void __cpdma_chan_submit(struct cpdma_chan *chan,
500 				struct cpdma_desc __iomem *desc)
501 {
502 	struct cpdma_ctlr		*ctlr = chan->ctlr;
503 	struct cpdma_desc __iomem	*prev = chan->tail;
504 	struct cpdma_desc_pool		*pool = ctlr->pool;
505 	dma_addr_t			desc_dma;
506 	u32				mode;
507 
508 	desc_dma = desc_phys(pool, desc);
509 
510 	/* simple case - idle channel */
511 	if (!chan->head) {
512 		chan->stats.head_enqueue++;
513 		chan->head = desc;
514 		chan->tail = desc;
515 		if (chan->state == CPDMA_STATE_ACTIVE)
516 			chan_write(chan, hdp, desc_dma);
517 		return;
518 	}
519 
520 	/* first chain the descriptor at the tail of the list */
521 	desc_write(prev, hw_next, desc_dma);
522 	chan->tail = desc;
523 	chan->stats.tail_enqueue++;
524 
525 	/* next check if EOQ has been triggered already */
526 	mode = desc_read(prev, hw_mode);
527 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
528 	    (chan->state == CPDMA_STATE_ACTIVE)) {
529 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
530 		chan_write(chan, hdp, desc_dma);
531 		chan->stats.misqueued++;
532 	}
533 }
534 
535 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
536 		      int len, int directed)
537 {
538 	struct cpdma_ctlr		*ctlr = chan->ctlr;
539 	struct cpdma_desc __iomem	*desc;
540 	dma_addr_t			buffer;
541 	unsigned long			flags;
542 	u32				mode;
543 	int				ret = 0;
544 
545 	spin_lock_irqsave(&chan->lock, flags);
546 
547 	if (chan->state == CPDMA_STATE_TEARDOWN) {
548 		ret = -EINVAL;
549 		goto unlock_ret;
550 	}
551 
552 	if (chan->count >= chan->desc_num)	{
553 		chan->stats.desc_alloc_fail++;
554 		ret = -ENOMEM;
555 		goto unlock_ret;
556 	}
557 
558 	desc = cpdma_desc_alloc(ctlr->pool);
559 	if (!desc) {
560 		chan->stats.desc_alloc_fail++;
561 		ret = -ENOMEM;
562 		goto unlock_ret;
563 	}
564 
565 	if (len < ctlr->params.min_packet_size) {
566 		len = ctlr->params.min_packet_size;
567 		chan->stats.runt_transmit_buff++;
568 	}
569 
570 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
571 	ret = dma_mapping_error(ctlr->dev, buffer);
572 	if (ret) {
573 		cpdma_desc_free(ctlr->pool, desc, 1);
574 		ret = -EINVAL;
575 		goto unlock_ret;
576 	}
577 
578 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
579 	cpdma_desc_to_port(chan, mode, directed);
580 
581 	desc_write(desc, hw_next,   0);
582 	desc_write(desc, hw_buffer, buffer);
583 	desc_write(desc, hw_len,    len);
584 	desc_write(desc, hw_mode,   mode | len);
585 	desc_write(desc, sw_token,  token);
586 	desc_write(desc, sw_buffer, buffer);
587 	desc_write(desc, sw_len,    len);
588 
589 	__cpdma_chan_submit(chan, desc);
590 
591 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
592 		chan_write(chan, rxfree, 1);
593 
594 	chan->count++;
595 
596 unlock_ret:
597 	spin_unlock_irqrestore(&chan->lock, flags);
598 	return ret;
599 }
600 EXPORT_SYMBOL_GPL(cpdma_chan_submit);
601 
602 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
603 {
604 	struct cpdma_ctlr	*ctlr = chan->ctlr;
605 	struct cpdma_desc_pool	*pool = ctlr->pool;
606 	bool			free_tx_desc;
607 	unsigned long		flags;
608 
609 	spin_lock_irqsave(&chan->lock, flags);
610 	free_tx_desc = (chan->count < chan->desc_num) &&
611 			 gen_pool_avail(pool->gen_pool);
612 	spin_unlock_irqrestore(&chan->lock, flags);
613 	return free_tx_desc;
614 }
615 EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc);
616 
617 static void __cpdma_chan_free(struct cpdma_chan *chan,
618 			      struct cpdma_desc __iomem *desc,
619 			      int outlen, int status)
620 {
621 	struct cpdma_ctlr		*ctlr = chan->ctlr;
622 	struct cpdma_desc_pool		*pool = ctlr->pool;
623 	dma_addr_t			buff_dma;
624 	int				origlen;
625 	void				*token;
626 
627 	token      = (void *)desc_read(desc, sw_token);
628 	buff_dma   = desc_read(desc, sw_buffer);
629 	origlen    = desc_read(desc, sw_len);
630 
631 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
632 	cpdma_desc_free(pool, desc, 1);
633 	(*chan->handler)(token, outlen, status);
634 }
635 
636 static int __cpdma_chan_process(struct cpdma_chan *chan)
637 {
638 	struct cpdma_ctlr		*ctlr = chan->ctlr;
639 	struct cpdma_desc __iomem	*desc;
640 	int				status, outlen;
641 	int				cb_status = 0;
642 	struct cpdma_desc_pool		*pool = ctlr->pool;
643 	dma_addr_t			desc_dma;
644 	unsigned long			flags;
645 
646 	spin_lock_irqsave(&chan->lock, flags);
647 
648 	desc = chan->head;
649 	if (!desc) {
650 		chan->stats.empty_dequeue++;
651 		status = -ENOENT;
652 		goto unlock_ret;
653 	}
654 	desc_dma = desc_phys(pool, desc);
655 
656 	status	= __raw_readl(&desc->hw_mode);
657 	outlen	= status & 0x7ff;
658 	if (status & CPDMA_DESC_OWNER) {
659 		chan->stats.busy_dequeue++;
660 		status = -EBUSY;
661 		goto unlock_ret;
662 	}
663 
664 	if (status & CPDMA_DESC_PASS_CRC)
665 		outlen -= CPDMA_DESC_CRC_LEN;
666 
667 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
668 			    CPDMA_DESC_PORT_MASK);
669 
670 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
671 	chan_write(chan, cp, desc_dma);
672 	chan->count--;
673 	chan->stats.good_dequeue++;
674 
675 	if (status & CPDMA_DESC_EOQ) {
676 		chan->stats.requeue++;
677 		chan_write(chan, hdp, desc_phys(pool, chan->head));
678 	}
679 
680 	spin_unlock_irqrestore(&chan->lock, flags);
681 	if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
682 		cb_status = -ENOSYS;
683 	else
684 		cb_status = status;
685 
686 	__cpdma_chan_free(chan, desc, outlen, cb_status);
687 	return status;
688 
689 unlock_ret:
690 	spin_unlock_irqrestore(&chan->lock, flags);
691 	return status;
692 }
693 
694 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
695 {
696 	int used = 0, ret = 0;
697 
698 	if (chan->state != CPDMA_STATE_ACTIVE)
699 		return -EINVAL;
700 
701 	while (used < quota) {
702 		ret = __cpdma_chan_process(chan);
703 		if (ret < 0)
704 			break;
705 		used++;
706 	}
707 	return used;
708 }
709 EXPORT_SYMBOL_GPL(cpdma_chan_process);
710 
711 int cpdma_chan_start(struct cpdma_chan *chan)
712 {
713 	struct cpdma_ctlr	*ctlr = chan->ctlr;
714 	struct cpdma_desc_pool	*pool = ctlr->pool;
715 	unsigned long		flags;
716 
717 	spin_lock_irqsave(&chan->lock, flags);
718 	if (chan->state != CPDMA_STATE_IDLE) {
719 		spin_unlock_irqrestore(&chan->lock, flags);
720 		return -EBUSY;
721 	}
722 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
723 		spin_unlock_irqrestore(&chan->lock, flags);
724 		return -EINVAL;
725 	}
726 	dma_reg_write(ctlr, chan->int_set, chan->mask);
727 	chan->state = CPDMA_STATE_ACTIVE;
728 	if (chan->head) {
729 		chan_write(chan, hdp, desc_phys(pool, chan->head));
730 		if (chan->rxfree)
731 			chan_write(chan, rxfree, chan->count);
732 	}
733 
734 	spin_unlock_irqrestore(&chan->lock, flags);
735 	return 0;
736 }
737 EXPORT_SYMBOL_GPL(cpdma_chan_start);
738 
739 int cpdma_chan_stop(struct cpdma_chan *chan)
740 {
741 	struct cpdma_ctlr	*ctlr = chan->ctlr;
742 	struct cpdma_desc_pool	*pool = ctlr->pool;
743 	unsigned long		flags;
744 	int			ret;
745 	unsigned		timeout;
746 
747 	spin_lock_irqsave(&chan->lock, flags);
748 	if (chan->state == CPDMA_STATE_TEARDOWN) {
749 		spin_unlock_irqrestore(&chan->lock, flags);
750 		return -EINVAL;
751 	}
752 
753 	chan->state = CPDMA_STATE_TEARDOWN;
754 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
755 
756 	/* trigger teardown */
757 	dma_reg_write(ctlr, chan->td, chan_linear(chan));
758 
759 	/* wait for teardown complete */
760 	timeout = 100 * 100; /* 100 ms */
761 	while (timeout) {
762 		u32 cp = chan_read(chan, cp);
763 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
764 			break;
765 		udelay(10);
766 		timeout--;
767 	}
768 	WARN_ON(!timeout);
769 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
770 
771 	/* handle completed packets */
772 	spin_unlock_irqrestore(&chan->lock, flags);
773 	do {
774 		ret = __cpdma_chan_process(chan);
775 		if (ret < 0)
776 			break;
777 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
778 	spin_lock_irqsave(&chan->lock, flags);
779 
780 	/* remaining packets haven't been tx/rx'ed, clean them up */
781 	while (chan->head) {
782 		struct cpdma_desc __iomem *desc = chan->head;
783 		dma_addr_t next_dma;
784 
785 		next_dma = desc_read(desc, hw_next);
786 		chan->head = desc_from_phys(pool, next_dma);
787 		chan->count--;
788 		chan->stats.teardown_dequeue++;
789 
790 		/* issue callback without locks held */
791 		spin_unlock_irqrestore(&chan->lock, flags);
792 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
793 		spin_lock_irqsave(&chan->lock, flags);
794 	}
795 
796 	chan->state = CPDMA_STATE_IDLE;
797 	spin_unlock_irqrestore(&chan->lock, flags);
798 	return 0;
799 }
800 EXPORT_SYMBOL_GPL(cpdma_chan_stop);
801 
802 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
803 {
804 	unsigned long flags;
805 
806 	spin_lock_irqsave(&chan->lock, flags);
807 	if (chan->state != CPDMA_STATE_ACTIVE) {
808 		spin_unlock_irqrestore(&chan->lock, flags);
809 		return -EINVAL;
810 	}
811 
812 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
813 		      chan->mask);
814 	spin_unlock_irqrestore(&chan->lock, flags);
815 
816 	return 0;
817 }
818 
819 struct cpdma_control_info {
820 	u32		reg;
821 	u32		shift, mask;
822 	int		access;
823 #define ACCESS_RO	BIT(0)
824 #define ACCESS_WO	BIT(1)
825 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
826 };
827 
828 static struct cpdma_control_info controls[] = {
829 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
830 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
831 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
832 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
833 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
834 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
835 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
836 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
837 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
838 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
839 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
840 };
841 
842 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
843 {
844 	unsigned long flags;
845 	struct cpdma_control_info *info = &controls[control];
846 	int ret;
847 
848 	spin_lock_irqsave(&ctlr->lock, flags);
849 
850 	ret = -ENOTSUPP;
851 	if (!ctlr->params.has_ext_regs)
852 		goto unlock_ret;
853 
854 	ret = -EINVAL;
855 	if (ctlr->state != CPDMA_STATE_ACTIVE)
856 		goto unlock_ret;
857 
858 	ret = -ENOENT;
859 	if (control < 0 || control >= ARRAY_SIZE(controls))
860 		goto unlock_ret;
861 
862 	ret = -EPERM;
863 	if ((info->access & ACCESS_RO) != ACCESS_RO)
864 		goto unlock_ret;
865 
866 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
867 
868 unlock_ret:
869 	spin_unlock_irqrestore(&ctlr->lock, flags);
870 	return ret;
871 }
872 
873 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
874 {
875 	unsigned long flags;
876 	struct cpdma_control_info *info = &controls[control];
877 	int ret;
878 	u32 val;
879 
880 	spin_lock_irqsave(&ctlr->lock, flags);
881 
882 	ret = -ENOTSUPP;
883 	if (!ctlr->params.has_ext_regs)
884 		goto unlock_ret;
885 
886 	ret = -EINVAL;
887 	if (ctlr->state != CPDMA_STATE_ACTIVE)
888 		goto unlock_ret;
889 
890 	ret = -ENOENT;
891 	if (control < 0 || control >= ARRAY_SIZE(controls))
892 		goto unlock_ret;
893 
894 	ret = -EPERM;
895 	if ((info->access & ACCESS_WO) != ACCESS_WO)
896 		goto unlock_ret;
897 
898 	val  = dma_reg_read(ctlr, info->reg);
899 	val &= ~(info->mask << info->shift);
900 	val |= (value & info->mask) << info->shift;
901 	dma_reg_write(ctlr, info->reg, val);
902 	ret = 0;
903 
904 unlock_ret:
905 	spin_unlock_irqrestore(&ctlr->lock, flags);
906 	return ret;
907 }
908 EXPORT_SYMBOL_GPL(cpdma_control_set);
909 
910 MODULE_LICENSE("GPL");
911