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/slab.h>
19 #include <linux/err.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/io.h>
22 
23 #include "davinci_cpdma.h"
24 
25 /* DMA Registers */
26 #define CPDMA_TXIDVER		0x00
27 #define CPDMA_TXCONTROL		0x04
28 #define CPDMA_TXTEARDOWN	0x08
29 #define CPDMA_RXIDVER		0x10
30 #define CPDMA_RXCONTROL		0x14
31 #define CPDMA_SOFTRESET		0x1c
32 #define CPDMA_RXTEARDOWN	0x18
33 #define CPDMA_TXINTSTATRAW	0x80
34 #define CPDMA_TXINTSTATMASKED	0x84
35 #define CPDMA_TXINTMASKSET	0x88
36 #define CPDMA_TXINTMASKCLEAR	0x8c
37 #define CPDMA_MACINVECTOR	0x90
38 #define CPDMA_MACEOIVECTOR	0x94
39 #define CPDMA_RXINTSTATRAW	0xa0
40 #define CPDMA_RXINTSTATMASKED	0xa4
41 #define CPDMA_RXINTMASKSET	0xa8
42 #define CPDMA_RXINTMASKCLEAR	0xac
43 #define CPDMA_DMAINTSTATRAW	0xb0
44 #define CPDMA_DMAINTSTATMASKED	0xb4
45 #define CPDMA_DMAINTMASKSET	0xb8
46 #define CPDMA_DMAINTMASKCLEAR	0xbc
47 #define CPDMA_DMAINT_HOSTERR	BIT(1)
48 
49 /* the following exist only if has_ext_regs is set */
50 #define CPDMA_DMACONTROL	0x20
51 #define CPDMA_DMASTATUS		0x24
52 #define CPDMA_RXBUFFOFS		0x28
53 #define CPDMA_EM_CONTROL	0x2c
54 
55 /* Descriptor mode bits */
56 #define CPDMA_DESC_SOP		BIT(31)
57 #define CPDMA_DESC_EOP		BIT(30)
58 #define CPDMA_DESC_OWNER	BIT(29)
59 #define CPDMA_DESC_EOQ		BIT(28)
60 #define CPDMA_DESC_TD_COMPLETE	BIT(27)
61 #define CPDMA_DESC_PASS_CRC	BIT(26)
62 
63 #define CPDMA_TEARDOWN_VALUE	0xfffffffc
64 
65 struct cpdma_desc {
66 	/* hardware fields */
67 	u32			hw_next;
68 	u32			hw_buffer;
69 	u32			hw_len;
70 	u32			hw_mode;
71 	/* software fields */
72 	void			*sw_token;
73 	u32			sw_buffer;
74 	u32			sw_len;
75 };
76 
77 struct cpdma_desc_pool {
78 	u32			phys;
79 	u32			hw_addr;
80 	void __iomem		*iomap;		/* ioremap map */
81 	void			*cpumap;	/* dma_alloc map */
82 	int			desc_size, mem_size;
83 	int			num_desc, used_desc;
84 	unsigned long		*bitmap;
85 	struct device		*dev;
86 	spinlock_t		lock;
87 };
88 
89 enum cpdma_state {
90 	CPDMA_STATE_IDLE,
91 	CPDMA_STATE_ACTIVE,
92 	CPDMA_STATE_TEARDOWN,
93 };
94 
95 const char *cpdma_state_str[] = { "idle", "active", "teardown" };
96 
97 struct cpdma_ctlr {
98 	enum cpdma_state	state;
99 	struct cpdma_params	params;
100 	struct device		*dev;
101 	struct cpdma_desc_pool	*pool;
102 	spinlock_t		lock;
103 	struct cpdma_chan	*channels[2 * CPDMA_MAX_CHANNELS];
104 };
105 
106 struct cpdma_chan {
107 	enum cpdma_state		state;
108 	struct cpdma_ctlr		*ctlr;
109 	int				chan_num;
110 	spinlock_t			lock;
111 	struct cpdma_desc __iomem	*head, *tail;
112 	int				count;
113 	void __iomem			*hdp, *cp, *rxfree;
114 	u32				mask;
115 	cpdma_handler_fn		handler;
116 	enum dma_data_direction		dir;
117 	struct cpdma_chan_stats		stats;
118 	/* offsets into dmaregs */
119 	int	int_set, int_clear, td;
120 };
121 
122 /* The following make access to common cpdma_ctlr params more readable */
123 #define dmaregs		params.dmaregs
124 #define num_chan	params.num_chan
125 
126 /* various accessors */
127 #define dma_reg_read(ctlr, ofs)		__raw_readl((ctlr)->dmaregs + (ofs))
128 #define chan_read(chan, fld)		__raw_readl((chan)->fld)
129 #define desc_read(desc, fld)		__raw_readl(&(desc)->fld)
130 #define dma_reg_write(ctlr, ofs, v)	__raw_writel(v, (ctlr)->dmaregs + (ofs))
131 #define chan_write(chan, fld, v)	__raw_writel(v, (chan)->fld)
132 #define desc_write(desc, fld, v)	__raw_writel((u32)(v), &(desc)->fld)
133 
134 /*
135  * Utility constructs for a cpdma descriptor pool.  Some devices (e.g. davinci
136  * emac) have dedicated on-chip memory for these descriptors.  Some other
137  * devices (e.g. cpsw switches) use plain old memory.  Descriptor pools
138  * abstract out these details
139  */
140 static struct cpdma_desc_pool *
141 cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
142 				int size, int align)
143 {
144 	int bitmap_size;
145 	struct cpdma_desc_pool *pool;
146 
147 	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
148 	if (!pool)
149 		return NULL;
150 
151 	spin_lock_init(&pool->lock);
152 
153 	pool->dev	= dev;
154 	pool->mem_size	= size;
155 	pool->desc_size	= ALIGN(sizeof(struct cpdma_desc), align);
156 	pool->num_desc	= size / pool->desc_size;
157 
158 	bitmap_size  = (pool->num_desc / BITS_PER_LONG) * sizeof(long);
159 	pool->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
160 	if (!pool->bitmap)
161 		goto fail;
162 
163 	if (phys) {
164 		pool->phys  = phys;
165 		pool->iomap = ioremap(phys, size);
166 		pool->hw_addr = hw_addr;
167 	} else {
168 		pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
169 						  GFP_KERNEL);
170 		pool->iomap = pool->cpumap;
171 		pool->hw_addr = pool->phys;
172 	}
173 
174 	if (pool->iomap)
175 		return pool;
176 
177 fail:
178 	kfree(pool->bitmap);
179 	kfree(pool);
180 	return NULL;
181 }
182 
183 static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
184 {
185 	unsigned long flags;
186 
187 	if (!pool)
188 		return;
189 
190 	spin_lock_irqsave(&pool->lock, flags);
191 	WARN_ON(pool->used_desc);
192 	kfree(pool->bitmap);
193 	if (pool->cpumap) {
194 		dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
195 				  pool->phys);
196 	} else {
197 		iounmap(pool->iomap);
198 	}
199 	spin_unlock_irqrestore(&pool->lock, flags);
200 	kfree(pool);
201 }
202 
203 static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
204 		  struct cpdma_desc __iomem *desc)
205 {
206 	if (!desc)
207 		return 0;
208 	return pool->hw_addr + (__force dma_addr_t)desc -
209 			    (__force dma_addr_t)pool->iomap;
210 }
211 
212 static inline struct cpdma_desc __iomem *
213 desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
214 {
215 	return dma ? pool->iomap + dma - pool->hw_addr : NULL;
216 }
217 
218 static struct cpdma_desc __iomem *
219 cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc)
220 {
221 	unsigned long flags;
222 	int index;
223 	struct cpdma_desc __iomem *desc = NULL;
224 
225 	spin_lock_irqsave(&pool->lock, flags);
226 
227 	index = bitmap_find_next_zero_area(pool->bitmap, pool->num_desc, 0,
228 					   num_desc, 0);
229 	if (index < pool->num_desc) {
230 		bitmap_set(pool->bitmap, index, num_desc);
231 		desc = pool->iomap + pool->desc_size * index;
232 		pool->used_desc++;
233 	}
234 
235 	spin_unlock_irqrestore(&pool->lock, flags);
236 	return desc;
237 }
238 
239 static void cpdma_desc_free(struct cpdma_desc_pool *pool,
240 			    struct cpdma_desc __iomem *desc, int num_desc)
241 {
242 	unsigned long flags, index;
243 
244 	index = ((unsigned long)desc - (unsigned long)pool->iomap) /
245 		pool->desc_size;
246 	spin_lock_irqsave(&pool->lock, flags);
247 	bitmap_clear(pool->bitmap, index, num_desc);
248 	pool->used_desc--;
249 	spin_unlock_irqrestore(&pool->lock, flags);
250 }
251 
252 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
253 {
254 	struct cpdma_ctlr *ctlr;
255 
256 	ctlr = kzalloc(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 		kfree(ctlr);
272 		return NULL;
273 	}
274 
275 	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
276 		ctlr->num_chan = CPDMA_MAX_CHANNELS;
277 	return ctlr;
278 }
279 
280 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
281 {
282 	unsigned long flags;
283 	int i;
284 
285 	spin_lock_irqsave(&ctlr->lock, flags);
286 	if (ctlr->state != CPDMA_STATE_IDLE) {
287 		spin_unlock_irqrestore(&ctlr->lock, flags);
288 		return -EBUSY;
289 	}
290 
291 	if (ctlr->params.has_soft_reset) {
292 		unsigned long timeout = jiffies + HZ/10;
293 
294 		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
295 		while (time_before(jiffies, timeout)) {
296 			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
297 				break;
298 		}
299 		WARN_ON(!time_before(jiffies, timeout));
300 	}
301 
302 	for (i = 0; i < ctlr->num_chan; i++) {
303 		__raw_writel(0, ctlr->params.txhdp + 4 * i);
304 		__raw_writel(0, ctlr->params.rxhdp + 4 * i);
305 		__raw_writel(0, ctlr->params.txcp + 4 * i);
306 		__raw_writel(0, ctlr->params.rxcp + 4 * i);
307 	}
308 
309 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
310 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
311 
312 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
313 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
314 
315 	ctlr->state = CPDMA_STATE_ACTIVE;
316 
317 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
318 		if (ctlr->channels[i])
319 			cpdma_chan_start(ctlr->channels[i]);
320 	}
321 	spin_unlock_irqrestore(&ctlr->lock, flags);
322 	return 0;
323 }
324 
325 int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
326 {
327 	unsigned long flags;
328 	int i;
329 
330 	spin_lock_irqsave(&ctlr->lock, flags);
331 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
332 		spin_unlock_irqrestore(&ctlr->lock, flags);
333 		return -EINVAL;
334 	}
335 
336 	ctlr->state = CPDMA_STATE_TEARDOWN;
337 
338 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
339 		if (ctlr->channels[i])
340 			cpdma_chan_stop(ctlr->channels[i]);
341 	}
342 
343 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
344 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
345 
346 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
347 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
348 
349 	ctlr->state = CPDMA_STATE_IDLE;
350 
351 	spin_unlock_irqrestore(&ctlr->lock, flags);
352 	return 0;
353 }
354 
355 int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr)
356 {
357 	struct device *dev = ctlr->dev;
358 	unsigned long flags;
359 	int i;
360 
361 	spin_lock_irqsave(&ctlr->lock, flags);
362 
363 	dev_info(dev, "CPDMA: state: %s", cpdma_state_str[ctlr->state]);
364 
365 	dev_info(dev, "CPDMA: txidver: %x",
366 		 dma_reg_read(ctlr, CPDMA_TXIDVER));
367 	dev_info(dev, "CPDMA: txcontrol: %x",
368 		 dma_reg_read(ctlr, CPDMA_TXCONTROL));
369 	dev_info(dev, "CPDMA: txteardown: %x",
370 		 dma_reg_read(ctlr, CPDMA_TXTEARDOWN));
371 	dev_info(dev, "CPDMA: rxidver: %x",
372 		 dma_reg_read(ctlr, CPDMA_RXIDVER));
373 	dev_info(dev, "CPDMA: rxcontrol: %x",
374 		 dma_reg_read(ctlr, CPDMA_RXCONTROL));
375 	dev_info(dev, "CPDMA: softreset: %x",
376 		 dma_reg_read(ctlr, CPDMA_SOFTRESET));
377 	dev_info(dev, "CPDMA: rxteardown: %x",
378 		 dma_reg_read(ctlr, CPDMA_RXTEARDOWN));
379 	dev_info(dev, "CPDMA: txintstatraw: %x",
380 		 dma_reg_read(ctlr, CPDMA_TXINTSTATRAW));
381 	dev_info(dev, "CPDMA: txintstatmasked: %x",
382 		 dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED));
383 	dev_info(dev, "CPDMA: txintmaskset: %x",
384 		 dma_reg_read(ctlr, CPDMA_TXINTMASKSET));
385 	dev_info(dev, "CPDMA: txintmaskclear: %x",
386 		 dma_reg_read(ctlr, CPDMA_TXINTMASKCLEAR));
387 	dev_info(dev, "CPDMA: macinvector: %x",
388 		 dma_reg_read(ctlr, CPDMA_MACINVECTOR));
389 	dev_info(dev, "CPDMA: maceoivector: %x",
390 		 dma_reg_read(ctlr, CPDMA_MACEOIVECTOR));
391 	dev_info(dev, "CPDMA: rxintstatraw: %x",
392 		 dma_reg_read(ctlr, CPDMA_RXINTSTATRAW));
393 	dev_info(dev, "CPDMA: rxintstatmasked: %x",
394 		 dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED));
395 	dev_info(dev, "CPDMA: rxintmaskset: %x",
396 		 dma_reg_read(ctlr, CPDMA_RXINTMASKSET));
397 	dev_info(dev, "CPDMA: rxintmaskclear: %x",
398 		 dma_reg_read(ctlr, CPDMA_RXINTMASKCLEAR));
399 	dev_info(dev, "CPDMA: dmaintstatraw: %x",
400 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATRAW));
401 	dev_info(dev, "CPDMA: dmaintstatmasked: %x",
402 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATMASKED));
403 	dev_info(dev, "CPDMA: dmaintmaskset: %x",
404 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKSET));
405 	dev_info(dev, "CPDMA: dmaintmaskclear: %x",
406 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKCLEAR));
407 
408 	if (!ctlr->params.has_ext_regs) {
409 		dev_info(dev, "CPDMA: dmacontrol: %x",
410 			 dma_reg_read(ctlr, CPDMA_DMACONTROL));
411 		dev_info(dev, "CPDMA: dmastatus: %x",
412 			 dma_reg_read(ctlr, CPDMA_DMASTATUS));
413 		dev_info(dev, "CPDMA: rxbuffofs: %x",
414 			 dma_reg_read(ctlr, CPDMA_RXBUFFOFS));
415 	}
416 
417 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
418 		if (ctlr->channels[i])
419 			cpdma_chan_dump(ctlr->channels[i]);
420 
421 	spin_unlock_irqrestore(&ctlr->lock, flags);
422 	return 0;
423 }
424 
425 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
426 {
427 	unsigned long flags;
428 	int ret = 0, i;
429 
430 	if (!ctlr)
431 		return -EINVAL;
432 
433 	spin_lock_irqsave(&ctlr->lock, flags);
434 	if (ctlr->state != CPDMA_STATE_IDLE)
435 		cpdma_ctlr_stop(ctlr);
436 
437 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
438 		if (ctlr->channels[i])
439 			cpdma_chan_destroy(ctlr->channels[i]);
440 	}
441 
442 	cpdma_desc_pool_destroy(ctlr->pool);
443 	spin_unlock_irqrestore(&ctlr->lock, flags);
444 	kfree(ctlr);
445 	return ret;
446 }
447 
448 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
449 {
450 	unsigned long flags;
451 	int i, reg;
452 
453 	spin_lock_irqsave(&ctlr->lock, flags);
454 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
455 		spin_unlock_irqrestore(&ctlr->lock, flags);
456 		return -EINVAL;
457 	}
458 
459 	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
460 	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
461 
462 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
463 		if (ctlr->channels[i])
464 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
465 	}
466 
467 	spin_unlock_irqrestore(&ctlr->lock, flags);
468 	return 0;
469 }
470 
471 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr)
472 {
473 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, 0);
474 }
475 
476 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
477 				     cpdma_handler_fn handler)
478 {
479 	struct cpdma_chan *chan;
480 	int ret, offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
481 	unsigned long flags;
482 
483 	if (__chan_linear(chan_num) >= ctlr->num_chan)
484 		return NULL;
485 
486 	ret = -ENOMEM;
487 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
488 	if (!chan)
489 		goto err_chan_alloc;
490 
491 	spin_lock_irqsave(&ctlr->lock, flags);
492 	ret = -EBUSY;
493 	if (ctlr->channels[chan_num])
494 		goto err_chan_busy;
495 
496 	chan->ctlr	= ctlr;
497 	chan->state	= CPDMA_STATE_IDLE;
498 	chan->chan_num	= chan_num;
499 	chan->handler	= handler;
500 
501 	if (is_rx_chan(chan)) {
502 		chan->hdp	= ctlr->params.rxhdp + offset;
503 		chan->cp	= ctlr->params.rxcp + offset;
504 		chan->rxfree	= ctlr->params.rxfree + offset;
505 		chan->int_set	= CPDMA_RXINTMASKSET;
506 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
507 		chan->td	= CPDMA_RXTEARDOWN;
508 		chan->dir	= DMA_FROM_DEVICE;
509 	} else {
510 		chan->hdp	= ctlr->params.txhdp + offset;
511 		chan->cp	= ctlr->params.txcp + offset;
512 		chan->int_set	= CPDMA_TXINTMASKSET;
513 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
514 		chan->td	= CPDMA_TXTEARDOWN;
515 		chan->dir	= DMA_TO_DEVICE;
516 	}
517 	chan->mask = BIT(chan_linear(chan));
518 
519 	spin_lock_init(&chan->lock);
520 
521 	ctlr->channels[chan_num] = chan;
522 	spin_unlock_irqrestore(&ctlr->lock, flags);
523 	return chan;
524 
525 err_chan_busy:
526 	spin_unlock_irqrestore(&ctlr->lock, flags);
527 	kfree(chan);
528 err_chan_alloc:
529 	return ERR_PTR(ret);
530 }
531 
532 int cpdma_chan_destroy(struct cpdma_chan *chan)
533 {
534 	struct cpdma_ctlr *ctlr = chan->ctlr;
535 	unsigned long flags;
536 
537 	if (!chan)
538 		return -EINVAL;
539 
540 	spin_lock_irqsave(&ctlr->lock, flags);
541 	if (chan->state != CPDMA_STATE_IDLE)
542 		cpdma_chan_stop(chan);
543 	ctlr->channels[chan->chan_num] = NULL;
544 	spin_unlock_irqrestore(&ctlr->lock, flags);
545 	kfree(chan);
546 	return 0;
547 }
548 
549 int cpdma_chan_get_stats(struct cpdma_chan *chan,
550 			 struct cpdma_chan_stats *stats)
551 {
552 	unsigned long flags;
553 	if (!chan)
554 		return -EINVAL;
555 	spin_lock_irqsave(&chan->lock, flags);
556 	memcpy(stats, &chan->stats, sizeof(*stats));
557 	spin_unlock_irqrestore(&chan->lock, flags);
558 	return 0;
559 }
560 
561 int cpdma_chan_dump(struct cpdma_chan *chan)
562 {
563 	unsigned long flags;
564 	struct device *dev = chan->ctlr->dev;
565 
566 	spin_lock_irqsave(&chan->lock, flags);
567 
568 	dev_info(dev, "channel %d (%s %d) state %s",
569 		 chan->chan_num, is_rx_chan(chan) ? "rx" : "tx",
570 		 chan_linear(chan), cpdma_state_str[chan->state]);
571 	dev_info(dev, "\thdp: %x\n", chan_read(chan, hdp));
572 	dev_info(dev, "\tcp: %x\n", chan_read(chan, cp));
573 	if (chan->rxfree) {
574 		dev_info(dev, "\trxfree: %x\n",
575 			 chan_read(chan, rxfree));
576 	}
577 
578 	dev_info(dev, "\tstats head_enqueue: %d\n",
579 		 chan->stats.head_enqueue);
580 	dev_info(dev, "\tstats tail_enqueue: %d\n",
581 		 chan->stats.tail_enqueue);
582 	dev_info(dev, "\tstats pad_enqueue: %d\n",
583 		 chan->stats.pad_enqueue);
584 	dev_info(dev, "\tstats misqueued: %d\n",
585 		 chan->stats.misqueued);
586 	dev_info(dev, "\tstats desc_alloc_fail: %d\n",
587 		 chan->stats.desc_alloc_fail);
588 	dev_info(dev, "\tstats pad_alloc_fail: %d\n",
589 		 chan->stats.pad_alloc_fail);
590 	dev_info(dev, "\tstats runt_receive_buff: %d\n",
591 		 chan->stats.runt_receive_buff);
592 	dev_info(dev, "\tstats runt_transmit_buff: %d\n",
593 		 chan->stats.runt_transmit_buff);
594 	dev_info(dev, "\tstats empty_dequeue: %d\n",
595 		 chan->stats.empty_dequeue);
596 	dev_info(dev, "\tstats busy_dequeue: %d\n",
597 		 chan->stats.busy_dequeue);
598 	dev_info(dev, "\tstats good_dequeue: %d\n",
599 		 chan->stats.good_dequeue);
600 	dev_info(dev, "\tstats requeue: %d\n",
601 		 chan->stats.requeue);
602 	dev_info(dev, "\tstats teardown_dequeue: %d\n",
603 		 chan->stats.teardown_dequeue);
604 
605 	spin_unlock_irqrestore(&chan->lock, flags);
606 	return 0;
607 }
608 
609 static void __cpdma_chan_submit(struct cpdma_chan *chan,
610 				struct cpdma_desc __iomem *desc)
611 {
612 	struct cpdma_ctlr		*ctlr = chan->ctlr;
613 	struct cpdma_desc __iomem	*prev = chan->tail;
614 	struct cpdma_desc_pool		*pool = ctlr->pool;
615 	dma_addr_t			desc_dma;
616 	u32				mode;
617 
618 	desc_dma = desc_phys(pool, desc);
619 
620 	/* simple case - idle channel */
621 	if (!chan->head) {
622 		chan->stats.head_enqueue++;
623 		chan->head = desc;
624 		chan->tail = desc;
625 		if (chan->state == CPDMA_STATE_ACTIVE)
626 			chan_write(chan, hdp, desc_dma);
627 		return;
628 	}
629 
630 	/* first chain the descriptor at the tail of the list */
631 	desc_write(prev, hw_next, desc_dma);
632 	chan->tail = desc;
633 	chan->stats.tail_enqueue++;
634 
635 	/* next check if EOQ has been triggered already */
636 	mode = desc_read(prev, hw_mode);
637 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
638 	    (chan->state == CPDMA_STATE_ACTIVE)) {
639 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
640 		chan_write(chan, hdp, desc_dma);
641 		chan->stats.misqueued++;
642 	}
643 }
644 
645 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
646 		      int len, gfp_t gfp_mask)
647 {
648 	struct cpdma_ctlr		*ctlr = chan->ctlr;
649 	struct cpdma_desc __iomem	*desc;
650 	dma_addr_t			buffer;
651 	unsigned long			flags;
652 	u32				mode;
653 	int				ret = 0;
654 
655 	spin_lock_irqsave(&chan->lock, flags);
656 
657 	if (chan->state == CPDMA_STATE_TEARDOWN) {
658 		ret = -EINVAL;
659 		goto unlock_ret;
660 	}
661 
662 	desc = cpdma_desc_alloc(ctlr->pool, 1);
663 	if (!desc) {
664 		chan->stats.desc_alloc_fail++;
665 		ret = -ENOMEM;
666 		goto unlock_ret;
667 	}
668 
669 	if (len < ctlr->params.min_packet_size) {
670 		len = ctlr->params.min_packet_size;
671 		chan->stats.runt_transmit_buff++;
672 	}
673 
674 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
675 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
676 
677 	desc_write(desc, hw_next,   0);
678 	desc_write(desc, hw_buffer, buffer);
679 	desc_write(desc, hw_len,    len);
680 	desc_write(desc, hw_mode,   mode | len);
681 	desc_write(desc, sw_token,  token);
682 	desc_write(desc, sw_buffer, buffer);
683 	desc_write(desc, sw_len,    len);
684 
685 	__cpdma_chan_submit(chan, desc);
686 
687 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
688 		chan_write(chan, rxfree, 1);
689 
690 	chan->count++;
691 
692 unlock_ret:
693 	spin_unlock_irqrestore(&chan->lock, flags);
694 	return ret;
695 }
696 
697 static void __cpdma_chan_free(struct cpdma_chan *chan,
698 			      struct cpdma_desc __iomem *desc,
699 			      int outlen, int status)
700 {
701 	struct cpdma_ctlr		*ctlr = chan->ctlr;
702 	struct cpdma_desc_pool		*pool = ctlr->pool;
703 	dma_addr_t			buff_dma;
704 	int				origlen;
705 	void				*token;
706 
707 	token      = (void *)desc_read(desc, sw_token);
708 	buff_dma   = desc_read(desc, sw_buffer);
709 	origlen    = desc_read(desc, sw_len);
710 
711 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
712 	cpdma_desc_free(pool, desc, 1);
713 	(*chan->handler)(token, outlen, status);
714 }
715 
716 static int __cpdma_chan_process(struct cpdma_chan *chan)
717 {
718 	struct cpdma_ctlr		*ctlr = chan->ctlr;
719 	struct cpdma_desc __iomem	*desc;
720 	int				status, outlen;
721 	struct cpdma_desc_pool		*pool = ctlr->pool;
722 	dma_addr_t			desc_dma;
723 	unsigned long			flags;
724 
725 	spin_lock_irqsave(&chan->lock, flags);
726 
727 	desc = chan->head;
728 	if (!desc) {
729 		chan->stats.empty_dequeue++;
730 		status = -ENOENT;
731 		goto unlock_ret;
732 	}
733 	desc_dma = desc_phys(pool, desc);
734 
735 	status	= __raw_readl(&desc->hw_mode);
736 	outlen	= status & 0x7ff;
737 	if (status & CPDMA_DESC_OWNER) {
738 		chan->stats.busy_dequeue++;
739 		status = -EBUSY;
740 		goto unlock_ret;
741 	}
742 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE);
743 
744 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
745 	chan_write(chan, cp, desc_dma);
746 	chan->count--;
747 	chan->stats.good_dequeue++;
748 
749 	if (status & CPDMA_DESC_EOQ) {
750 		chan->stats.requeue++;
751 		chan_write(chan, hdp, desc_phys(pool, chan->head));
752 	}
753 
754 	spin_unlock_irqrestore(&chan->lock, flags);
755 
756 	__cpdma_chan_free(chan, desc, outlen, status);
757 	return status;
758 
759 unlock_ret:
760 	spin_unlock_irqrestore(&chan->lock, flags);
761 	return status;
762 }
763 
764 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
765 {
766 	int used = 0, ret = 0;
767 
768 	if (chan->state != CPDMA_STATE_ACTIVE)
769 		return -EINVAL;
770 
771 	while (used < quota) {
772 		ret = __cpdma_chan_process(chan);
773 		if (ret < 0)
774 			break;
775 		used++;
776 	}
777 	return used;
778 }
779 
780 int cpdma_chan_start(struct cpdma_chan *chan)
781 {
782 	struct cpdma_ctlr	*ctlr = chan->ctlr;
783 	struct cpdma_desc_pool	*pool = ctlr->pool;
784 	unsigned long		flags;
785 
786 	spin_lock_irqsave(&chan->lock, flags);
787 	if (chan->state != CPDMA_STATE_IDLE) {
788 		spin_unlock_irqrestore(&chan->lock, flags);
789 		return -EBUSY;
790 	}
791 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
792 		spin_unlock_irqrestore(&chan->lock, flags);
793 		return -EINVAL;
794 	}
795 	dma_reg_write(ctlr, chan->int_set, chan->mask);
796 	chan->state = CPDMA_STATE_ACTIVE;
797 	if (chan->head) {
798 		chan_write(chan, hdp, desc_phys(pool, chan->head));
799 		if (chan->rxfree)
800 			chan_write(chan, rxfree, chan->count);
801 	}
802 
803 	spin_unlock_irqrestore(&chan->lock, flags);
804 	return 0;
805 }
806 
807 int cpdma_chan_stop(struct cpdma_chan *chan)
808 {
809 	struct cpdma_ctlr	*ctlr = chan->ctlr;
810 	struct cpdma_desc_pool	*pool = ctlr->pool;
811 	unsigned long		flags;
812 	int			ret;
813 	unsigned long		timeout;
814 
815 	spin_lock_irqsave(&chan->lock, flags);
816 	if (chan->state != CPDMA_STATE_ACTIVE) {
817 		spin_unlock_irqrestore(&chan->lock, flags);
818 		return -EINVAL;
819 	}
820 
821 	chan->state = CPDMA_STATE_TEARDOWN;
822 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
823 
824 	/* trigger teardown */
825 	dma_reg_write(ctlr, chan->td, chan->chan_num);
826 
827 	/* wait for teardown complete */
828 	timeout = jiffies + HZ/10;	/* 100 msec */
829 	while (time_before(jiffies, timeout)) {
830 		u32 cp = chan_read(chan, cp);
831 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
832 			break;
833 		cpu_relax();
834 	}
835 	WARN_ON(!time_before(jiffies, timeout));
836 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
837 
838 	/* handle completed packets */
839 	do {
840 		ret = __cpdma_chan_process(chan);
841 		if (ret < 0)
842 			break;
843 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
844 
845 	/* remaining packets haven't been tx/rx'ed, clean them up */
846 	while (chan->head) {
847 		struct cpdma_desc __iomem *desc = chan->head;
848 		dma_addr_t next_dma;
849 
850 		next_dma = desc_read(desc, hw_next);
851 		chan->head = desc_from_phys(pool, next_dma);
852 		chan->stats.teardown_dequeue++;
853 
854 		/* issue callback without locks held */
855 		spin_unlock_irqrestore(&chan->lock, flags);
856 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
857 		spin_lock_irqsave(&chan->lock, flags);
858 	}
859 
860 	chan->state = CPDMA_STATE_IDLE;
861 	spin_unlock_irqrestore(&chan->lock, flags);
862 	return 0;
863 }
864 
865 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
866 {
867 	unsigned long flags;
868 
869 	spin_lock_irqsave(&chan->lock, flags);
870 	if (chan->state != CPDMA_STATE_ACTIVE) {
871 		spin_unlock_irqrestore(&chan->lock, flags);
872 		return -EINVAL;
873 	}
874 
875 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
876 		      chan->mask);
877 	spin_unlock_irqrestore(&chan->lock, flags);
878 
879 	return 0;
880 }
881 
882 struct cpdma_control_info {
883 	u32		reg;
884 	u32		shift, mask;
885 	int		access;
886 #define ACCESS_RO	BIT(0)
887 #define ACCESS_WO	BIT(1)
888 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
889 };
890 
891 struct cpdma_control_info controls[] = {
892 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
893 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
894 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
895 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
896 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
897 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
898 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
899 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
900 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
901 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
902 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
903 };
904 
905 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
906 {
907 	unsigned long flags;
908 	struct cpdma_control_info *info = &controls[control];
909 	int ret;
910 
911 	spin_lock_irqsave(&ctlr->lock, flags);
912 
913 	ret = -ENOTSUPP;
914 	if (!ctlr->params.has_ext_regs)
915 		goto unlock_ret;
916 
917 	ret = -EINVAL;
918 	if (ctlr->state != CPDMA_STATE_ACTIVE)
919 		goto unlock_ret;
920 
921 	ret = -ENOENT;
922 	if (control < 0 || control >= ARRAY_SIZE(controls))
923 		goto unlock_ret;
924 
925 	ret = -EPERM;
926 	if ((info->access & ACCESS_RO) != ACCESS_RO)
927 		goto unlock_ret;
928 
929 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
930 
931 unlock_ret:
932 	spin_unlock_irqrestore(&ctlr->lock, flags);
933 	return ret;
934 }
935 
936 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
937 {
938 	unsigned long flags;
939 	struct cpdma_control_info *info = &controls[control];
940 	int ret;
941 	u32 val;
942 
943 	spin_lock_irqsave(&ctlr->lock, flags);
944 
945 	ret = -ENOTSUPP;
946 	if (!ctlr->params.has_ext_regs)
947 		goto unlock_ret;
948 
949 	ret = -EINVAL;
950 	if (ctlr->state != CPDMA_STATE_ACTIVE)
951 		goto unlock_ret;
952 
953 	ret = -ENOENT;
954 	if (control < 0 || control >= ARRAY_SIZE(controls))
955 		goto unlock_ret;
956 
957 	ret = -EPERM;
958 	if ((info->access & ACCESS_WO) != ACCESS_WO)
959 		goto unlock_ret;
960 
961 	val  = dma_reg_read(ctlr, info->reg);
962 	val &= ~(info->mask << info->shift);
963 	val |= (value & info->mask) << info->shift;
964 	dma_reg_write(ctlr, info->reg, val);
965 	ret = 0;
966 
967 unlock_ret:
968 	spin_unlock_irqrestore(&ctlr->lock, flags);
969 	return ret;
970 }
971