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 	int ret = 0, i;
361 
362 	if (!ctlr)
363 		return -EINVAL;
364 
365 	if (ctlr->state != CPDMA_STATE_IDLE)
366 		cpdma_ctlr_stop(ctlr);
367 
368 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
369 		cpdma_chan_destroy(ctlr->channels[i]);
370 
371 	cpdma_desc_pool_destroy(ctlr->pool);
372 	return ret;
373 }
374 EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);
375 
376 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
377 {
378 	unsigned long flags;
379 	int i, reg;
380 
381 	spin_lock_irqsave(&ctlr->lock, flags);
382 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
383 		spin_unlock_irqrestore(&ctlr->lock, flags);
384 		return -EINVAL;
385 	}
386 
387 	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
388 	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
389 
390 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
391 		if (ctlr->channels[i])
392 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
393 	}
394 
395 	spin_unlock_irqrestore(&ctlr->lock, flags);
396 	return 0;
397 }
398 EXPORT_SYMBOL_GPL(cpdma_ctlr_int_ctrl);
399 
400 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
401 {
402 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
403 }
404 EXPORT_SYMBOL_GPL(cpdma_ctlr_eoi);
405 
406 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
407 				     cpdma_handler_fn handler)
408 {
409 	struct cpdma_chan *chan;
410 	int offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
411 	unsigned long flags;
412 
413 	if (__chan_linear(chan_num) >= ctlr->num_chan)
414 		return NULL;
415 
416 	chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
417 	if (!chan)
418 		return ERR_PTR(-ENOMEM);
419 
420 	spin_lock_irqsave(&ctlr->lock, flags);
421 	if (ctlr->channels[chan_num]) {
422 		spin_unlock_irqrestore(&ctlr->lock, flags);
423 		devm_kfree(ctlr->dev, chan);
424 		return ERR_PTR(-EBUSY);
425 	}
426 
427 	chan->ctlr	= ctlr;
428 	chan->state	= CPDMA_STATE_IDLE;
429 	chan->chan_num	= chan_num;
430 	chan->handler	= handler;
431 	chan->desc_num = ctlr->pool->num_desc / 2;
432 
433 	if (is_rx_chan(chan)) {
434 		chan->hdp	= ctlr->params.rxhdp + offset;
435 		chan->cp	= ctlr->params.rxcp + offset;
436 		chan->rxfree	= ctlr->params.rxfree + offset;
437 		chan->int_set	= CPDMA_RXINTMASKSET;
438 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
439 		chan->td	= CPDMA_RXTEARDOWN;
440 		chan->dir	= DMA_FROM_DEVICE;
441 	} else {
442 		chan->hdp	= ctlr->params.txhdp + offset;
443 		chan->cp	= ctlr->params.txcp + offset;
444 		chan->int_set	= CPDMA_TXINTMASKSET;
445 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
446 		chan->td	= CPDMA_TXTEARDOWN;
447 		chan->dir	= DMA_TO_DEVICE;
448 	}
449 	chan->mask = BIT(chan_linear(chan));
450 
451 	spin_lock_init(&chan->lock);
452 
453 	ctlr->channels[chan_num] = chan;
454 	spin_unlock_irqrestore(&ctlr->lock, flags);
455 	return chan;
456 }
457 EXPORT_SYMBOL_GPL(cpdma_chan_create);
458 
459 int cpdma_chan_get_rx_buf_num(struct cpdma_ctlr *ctlr)
460 {
461 	return ctlr->pool->num_desc / 2;
462 }
463 EXPORT_SYMBOL_GPL(cpdma_chan_get_rx_buf_num);
464 
465 int cpdma_chan_destroy(struct cpdma_chan *chan)
466 {
467 	struct cpdma_ctlr *ctlr;
468 	unsigned long flags;
469 
470 	if (!chan)
471 		return -EINVAL;
472 	ctlr = chan->ctlr;
473 
474 	spin_lock_irqsave(&ctlr->lock, flags);
475 	if (chan->state != CPDMA_STATE_IDLE)
476 		cpdma_chan_stop(chan);
477 	ctlr->channels[chan->chan_num] = NULL;
478 	spin_unlock_irqrestore(&ctlr->lock, flags);
479 	return 0;
480 }
481 EXPORT_SYMBOL_GPL(cpdma_chan_destroy);
482 
483 int cpdma_chan_get_stats(struct cpdma_chan *chan,
484 			 struct cpdma_chan_stats *stats)
485 {
486 	unsigned long flags;
487 	if (!chan)
488 		return -EINVAL;
489 	spin_lock_irqsave(&chan->lock, flags);
490 	memcpy(stats, &chan->stats, sizeof(*stats));
491 	spin_unlock_irqrestore(&chan->lock, flags);
492 	return 0;
493 }
494 EXPORT_SYMBOL_GPL(cpdma_chan_get_stats);
495 
496 static void __cpdma_chan_submit(struct cpdma_chan *chan,
497 				struct cpdma_desc __iomem *desc)
498 {
499 	struct cpdma_ctlr		*ctlr = chan->ctlr;
500 	struct cpdma_desc __iomem	*prev = chan->tail;
501 	struct cpdma_desc_pool		*pool = ctlr->pool;
502 	dma_addr_t			desc_dma;
503 	u32				mode;
504 
505 	desc_dma = desc_phys(pool, desc);
506 
507 	/* simple case - idle channel */
508 	if (!chan->head) {
509 		chan->stats.head_enqueue++;
510 		chan->head = desc;
511 		chan->tail = desc;
512 		if (chan->state == CPDMA_STATE_ACTIVE)
513 			chan_write(chan, hdp, desc_dma);
514 		return;
515 	}
516 
517 	/* first chain the descriptor at the tail of the list */
518 	desc_write(prev, hw_next, desc_dma);
519 	chan->tail = desc;
520 	chan->stats.tail_enqueue++;
521 
522 	/* next check if EOQ has been triggered already */
523 	mode = desc_read(prev, hw_mode);
524 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
525 	    (chan->state == CPDMA_STATE_ACTIVE)) {
526 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
527 		chan_write(chan, hdp, desc_dma);
528 		chan->stats.misqueued++;
529 	}
530 }
531 
532 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
533 		      int len, int directed)
534 {
535 	struct cpdma_ctlr		*ctlr = chan->ctlr;
536 	struct cpdma_desc __iomem	*desc;
537 	dma_addr_t			buffer;
538 	unsigned long			flags;
539 	u32				mode;
540 	int				ret = 0;
541 
542 	spin_lock_irqsave(&chan->lock, flags);
543 
544 	if (chan->state == CPDMA_STATE_TEARDOWN) {
545 		ret = -EINVAL;
546 		goto unlock_ret;
547 	}
548 
549 	if (chan->count >= chan->desc_num)	{
550 		chan->stats.desc_alloc_fail++;
551 		ret = -ENOMEM;
552 		goto unlock_ret;
553 	}
554 
555 	desc = cpdma_desc_alloc(ctlr->pool);
556 	if (!desc) {
557 		chan->stats.desc_alloc_fail++;
558 		ret = -ENOMEM;
559 		goto unlock_ret;
560 	}
561 
562 	if (len < ctlr->params.min_packet_size) {
563 		len = ctlr->params.min_packet_size;
564 		chan->stats.runt_transmit_buff++;
565 	}
566 
567 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
568 	ret = dma_mapping_error(ctlr->dev, buffer);
569 	if (ret) {
570 		cpdma_desc_free(ctlr->pool, desc, 1);
571 		ret = -EINVAL;
572 		goto unlock_ret;
573 	}
574 
575 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
576 	cpdma_desc_to_port(chan, mode, directed);
577 
578 	desc_write(desc, hw_next,   0);
579 	desc_write(desc, hw_buffer, buffer);
580 	desc_write(desc, hw_len,    len);
581 	desc_write(desc, hw_mode,   mode | len);
582 	desc_write(desc, sw_token,  token);
583 	desc_write(desc, sw_buffer, buffer);
584 	desc_write(desc, sw_len,    len);
585 
586 	__cpdma_chan_submit(chan, desc);
587 
588 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
589 		chan_write(chan, rxfree, 1);
590 
591 	chan->count++;
592 
593 unlock_ret:
594 	spin_unlock_irqrestore(&chan->lock, flags);
595 	return ret;
596 }
597 EXPORT_SYMBOL_GPL(cpdma_chan_submit);
598 
599 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
600 {
601 	struct cpdma_ctlr	*ctlr = chan->ctlr;
602 	struct cpdma_desc_pool	*pool = ctlr->pool;
603 	bool			free_tx_desc;
604 	unsigned long		flags;
605 
606 	spin_lock_irqsave(&chan->lock, flags);
607 	free_tx_desc = (chan->count < chan->desc_num) &&
608 			 gen_pool_avail(pool->gen_pool);
609 	spin_unlock_irqrestore(&chan->lock, flags);
610 	return free_tx_desc;
611 }
612 EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc);
613 
614 static void __cpdma_chan_free(struct cpdma_chan *chan,
615 			      struct cpdma_desc __iomem *desc,
616 			      int outlen, int status)
617 {
618 	struct cpdma_ctlr		*ctlr = chan->ctlr;
619 	struct cpdma_desc_pool		*pool = ctlr->pool;
620 	dma_addr_t			buff_dma;
621 	int				origlen;
622 	void				*token;
623 
624 	token      = (void *)desc_read(desc, sw_token);
625 	buff_dma   = desc_read(desc, sw_buffer);
626 	origlen    = desc_read(desc, sw_len);
627 
628 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
629 	cpdma_desc_free(pool, desc, 1);
630 	(*chan->handler)(token, outlen, status);
631 }
632 
633 static int __cpdma_chan_process(struct cpdma_chan *chan)
634 {
635 	struct cpdma_ctlr		*ctlr = chan->ctlr;
636 	struct cpdma_desc __iomem	*desc;
637 	int				status, outlen;
638 	int				cb_status = 0;
639 	struct cpdma_desc_pool		*pool = ctlr->pool;
640 	dma_addr_t			desc_dma;
641 	unsigned long			flags;
642 
643 	spin_lock_irqsave(&chan->lock, flags);
644 
645 	desc = chan->head;
646 	if (!desc) {
647 		chan->stats.empty_dequeue++;
648 		status = -ENOENT;
649 		goto unlock_ret;
650 	}
651 	desc_dma = desc_phys(pool, desc);
652 
653 	status	= __raw_readl(&desc->hw_mode);
654 	outlen	= status & 0x7ff;
655 	if (status & CPDMA_DESC_OWNER) {
656 		chan->stats.busy_dequeue++;
657 		status = -EBUSY;
658 		goto unlock_ret;
659 	}
660 
661 	if (status & CPDMA_DESC_PASS_CRC)
662 		outlen -= CPDMA_DESC_CRC_LEN;
663 
664 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
665 			    CPDMA_DESC_PORT_MASK);
666 
667 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
668 	chan_write(chan, cp, desc_dma);
669 	chan->count--;
670 	chan->stats.good_dequeue++;
671 
672 	if (status & CPDMA_DESC_EOQ) {
673 		chan->stats.requeue++;
674 		chan_write(chan, hdp, desc_phys(pool, chan->head));
675 	}
676 
677 	spin_unlock_irqrestore(&chan->lock, flags);
678 	if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
679 		cb_status = -ENOSYS;
680 	else
681 		cb_status = status;
682 
683 	__cpdma_chan_free(chan, desc, outlen, cb_status);
684 	return status;
685 
686 unlock_ret:
687 	spin_unlock_irqrestore(&chan->lock, flags);
688 	return status;
689 }
690 
691 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
692 {
693 	int used = 0, ret = 0;
694 
695 	if (chan->state != CPDMA_STATE_ACTIVE)
696 		return -EINVAL;
697 
698 	while (used < quota) {
699 		ret = __cpdma_chan_process(chan);
700 		if (ret < 0)
701 			break;
702 		used++;
703 	}
704 	return used;
705 }
706 EXPORT_SYMBOL_GPL(cpdma_chan_process);
707 
708 int cpdma_chan_start(struct cpdma_chan *chan)
709 {
710 	struct cpdma_ctlr	*ctlr = chan->ctlr;
711 	struct cpdma_desc_pool	*pool = ctlr->pool;
712 	unsigned long		flags;
713 
714 	spin_lock_irqsave(&chan->lock, flags);
715 	if (chan->state != CPDMA_STATE_IDLE) {
716 		spin_unlock_irqrestore(&chan->lock, flags);
717 		return -EBUSY;
718 	}
719 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
720 		spin_unlock_irqrestore(&chan->lock, flags);
721 		return -EINVAL;
722 	}
723 	dma_reg_write(ctlr, chan->int_set, chan->mask);
724 	chan->state = CPDMA_STATE_ACTIVE;
725 	if (chan->head) {
726 		chan_write(chan, hdp, desc_phys(pool, chan->head));
727 		if (chan->rxfree)
728 			chan_write(chan, rxfree, chan->count);
729 	}
730 
731 	spin_unlock_irqrestore(&chan->lock, flags);
732 	return 0;
733 }
734 EXPORT_SYMBOL_GPL(cpdma_chan_start);
735 
736 int cpdma_chan_stop(struct cpdma_chan *chan)
737 {
738 	struct cpdma_ctlr	*ctlr = chan->ctlr;
739 	struct cpdma_desc_pool	*pool = ctlr->pool;
740 	unsigned long		flags;
741 	int			ret;
742 	unsigned		timeout;
743 
744 	spin_lock_irqsave(&chan->lock, flags);
745 	if (chan->state == CPDMA_STATE_TEARDOWN) {
746 		spin_unlock_irqrestore(&chan->lock, flags);
747 		return -EINVAL;
748 	}
749 
750 	chan->state = CPDMA_STATE_TEARDOWN;
751 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
752 
753 	/* trigger teardown */
754 	dma_reg_write(ctlr, chan->td, chan_linear(chan));
755 
756 	/* wait for teardown complete */
757 	timeout = 100 * 100; /* 100 ms */
758 	while (timeout) {
759 		u32 cp = chan_read(chan, cp);
760 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
761 			break;
762 		udelay(10);
763 		timeout--;
764 	}
765 	WARN_ON(!timeout);
766 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
767 
768 	/* handle completed packets */
769 	spin_unlock_irqrestore(&chan->lock, flags);
770 	do {
771 		ret = __cpdma_chan_process(chan);
772 		if (ret < 0)
773 			break;
774 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
775 	spin_lock_irqsave(&chan->lock, flags);
776 
777 	/* remaining packets haven't been tx/rx'ed, clean them up */
778 	while (chan->head) {
779 		struct cpdma_desc __iomem *desc = chan->head;
780 		dma_addr_t next_dma;
781 
782 		next_dma = desc_read(desc, hw_next);
783 		chan->head = desc_from_phys(pool, next_dma);
784 		chan->count--;
785 		chan->stats.teardown_dequeue++;
786 
787 		/* issue callback without locks held */
788 		spin_unlock_irqrestore(&chan->lock, flags);
789 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
790 		spin_lock_irqsave(&chan->lock, flags);
791 	}
792 
793 	chan->state = CPDMA_STATE_IDLE;
794 	spin_unlock_irqrestore(&chan->lock, flags);
795 	return 0;
796 }
797 EXPORT_SYMBOL_GPL(cpdma_chan_stop);
798 
799 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
800 {
801 	unsigned long flags;
802 
803 	spin_lock_irqsave(&chan->lock, flags);
804 	if (chan->state != CPDMA_STATE_ACTIVE) {
805 		spin_unlock_irqrestore(&chan->lock, flags);
806 		return -EINVAL;
807 	}
808 
809 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
810 		      chan->mask);
811 	spin_unlock_irqrestore(&chan->lock, flags);
812 
813 	return 0;
814 }
815 
816 struct cpdma_control_info {
817 	u32		reg;
818 	u32		shift, mask;
819 	int		access;
820 #define ACCESS_RO	BIT(0)
821 #define ACCESS_WO	BIT(1)
822 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
823 };
824 
825 static struct cpdma_control_info controls[] = {
826 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
827 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
828 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
829 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
830 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
831 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
832 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
833 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
834 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
835 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
836 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
837 };
838 
839 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
840 {
841 	unsigned long flags;
842 	struct cpdma_control_info *info = &controls[control];
843 	int ret;
844 
845 	spin_lock_irqsave(&ctlr->lock, flags);
846 
847 	ret = -ENOTSUPP;
848 	if (!ctlr->params.has_ext_regs)
849 		goto unlock_ret;
850 
851 	ret = -EINVAL;
852 	if (ctlr->state != CPDMA_STATE_ACTIVE)
853 		goto unlock_ret;
854 
855 	ret = -ENOENT;
856 	if (control < 0 || control >= ARRAY_SIZE(controls))
857 		goto unlock_ret;
858 
859 	ret = -EPERM;
860 	if ((info->access & ACCESS_RO) != ACCESS_RO)
861 		goto unlock_ret;
862 
863 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
864 
865 unlock_ret:
866 	spin_unlock_irqrestore(&ctlr->lock, flags);
867 	return ret;
868 }
869 
870 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
871 {
872 	unsigned long flags;
873 	struct cpdma_control_info *info = &controls[control];
874 	int ret;
875 	u32 val;
876 
877 	spin_lock_irqsave(&ctlr->lock, flags);
878 
879 	ret = -ENOTSUPP;
880 	if (!ctlr->params.has_ext_regs)
881 		goto unlock_ret;
882 
883 	ret = -EINVAL;
884 	if (ctlr->state != CPDMA_STATE_ACTIVE)
885 		goto unlock_ret;
886 
887 	ret = -ENOENT;
888 	if (control < 0 || control >= ARRAY_SIZE(controls))
889 		goto unlock_ret;
890 
891 	ret = -EPERM;
892 	if ((info->access & ACCESS_WO) != ACCESS_WO)
893 		goto unlock_ret;
894 
895 	val  = dma_reg_read(ctlr, info->reg);
896 	val &= ~(info->mask << info->shift);
897 	val |= (value & info->mask) << info->shift;
898 	dma_reg_write(ctlr, info->reg, val);
899 	ret = 0;
900 
901 unlock_ret:
902 	spin_unlock_irqrestore(&ctlr->lock, flags);
903 	return ret;
904 }
905 EXPORT_SYMBOL_GPL(cpdma_control_set);
906 
907 MODULE_LICENSE("GPL");
908