xref: /linux/drivers/net/ethernet/ti/davinci_cpdma.c (revision a508da6cc0093171833efb8376b00473f24221b9)
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 static 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 EXPORT_SYMBOL_GPL(cpdma_ctlr_create);
280 
281 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
282 {
283 	unsigned long flags;
284 	int i;
285 
286 	spin_lock_irqsave(&ctlr->lock, flags);
287 	if (ctlr->state != CPDMA_STATE_IDLE) {
288 		spin_unlock_irqrestore(&ctlr->lock, flags);
289 		return -EBUSY;
290 	}
291 
292 	if (ctlr->params.has_soft_reset) {
293 		unsigned long timeout = jiffies + HZ/10;
294 
295 		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
296 		while (time_before(jiffies, timeout)) {
297 			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
298 				break;
299 		}
300 		WARN_ON(!time_before(jiffies, 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_ACTIVE) {
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_dump(struct cpdma_ctlr *ctlr)
359 {
360 	struct device *dev = ctlr->dev;
361 	unsigned long flags;
362 	int i;
363 
364 	spin_lock_irqsave(&ctlr->lock, flags);
365 
366 	dev_info(dev, "CPDMA: state: %s", cpdma_state_str[ctlr->state]);
367 
368 	dev_info(dev, "CPDMA: txidver: %x",
369 		 dma_reg_read(ctlr, CPDMA_TXIDVER));
370 	dev_info(dev, "CPDMA: txcontrol: %x",
371 		 dma_reg_read(ctlr, CPDMA_TXCONTROL));
372 	dev_info(dev, "CPDMA: txteardown: %x",
373 		 dma_reg_read(ctlr, CPDMA_TXTEARDOWN));
374 	dev_info(dev, "CPDMA: rxidver: %x",
375 		 dma_reg_read(ctlr, CPDMA_RXIDVER));
376 	dev_info(dev, "CPDMA: rxcontrol: %x",
377 		 dma_reg_read(ctlr, CPDMA_RXCONTROL));
378 	dev_info(dev, "CPDMA: softreset: %x",
379 		 dma_reg_read(ctlr, CPDMA_SOFTRESET));
380 	dev_info(dev, "CPDMA: rxteardown: %x",
381 		 dma_reg_read(ctlr, CPDMA_RXTEARDOWN));
382 	dev_info(dev, "CPDMA: txintstatraw: %x",
383 		 dma_reg_read(ctlr, CPDMA_TXINTSTATRAW));
384 	dev_info(dev, "CPDMA: txintstatmasked: %x",
385 		 dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED));
386 	dev_info(dev, "CPDMA: txintmaskset: %x",
387 		 dma_reg_read(ctlr, CPDMA_TXINTMASKSET));
388 	dev_info(dev, "CPDMA: txintmaskclear: %x",
389 		 dma_reg_read(ctlr, CPDMA_TXINTMASKCLEAR));
390 	dev_info(dev, "CPDMA: macinvector: %x",
391 		 dma_reg_read(ctlr, CPDMA_MACINVECTOR));
392 	dev_info(dev, "CPDMA: maceoivector: %x",
393 		 dma_reg_read(ctlr, CPDMA_MACEOIVECTOR));
394 	dev_info(dev, "CPDMA: rxintstatraw: %x",
395 		 dma_reg_read(ctlr, CPDMA_RXINTSTATRAW));
396 	dev_info(dev, "CPDMA: rxintstatmasked: %x",
397 		 dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED));
398 	dev_info(dev, "CPDMA: rxintmaskset: %x",
399 		 dma_reg_read(ctlr, CPDMA_RXINTMASKSET));
400 	dev_info(dev, "CPDMA: rxintmaskclear: %x",
401 		 dma_reg_read(ctlr, CPDMA_RXINTMASKCLEAR));
402 	dev_info(dev, "CPDMA: dmaintstatraw: %x",
403 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATRAW));
404 	dev_info(dev, "CPDMA: dmaintstatmasked: %x",
405 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATMASKED));
406 	dev_info(dev, "CPDMA: dmaintmaskset: %x",
407 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKSET));
408 	dev_info(dev, "CPDMA: dmaintmaskclear: %x",
409 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKCLEAR));
410 
411 	if (!ctlr->params.has_ext_regs) {
412 		dev_info(dev, "CPDMA: dmacontrol: %x",
413 			 dma_reg_read(ctlr, CPDMA_DMACONTROL));
414 		dev_info(dev, "CPDMA: dmastatus: %x",
415 			 dma_reg_read(ctlr, CPDMA_DMASTATUS));
416 		dev_info(dev, "CPDMA: rxbuffofs: %x",
417 			 dma_reg_read(ctlr, CPDMA_RXBUFFOFS));
418 	}
419 
420 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
421 		if (ctlr->channels[i])
422 			cpdma_chan_dump(ctlr->channels[i]);
423 
424 	spin_unlock_irqrestore(&ctlr->lock, flags);
425 	return 0;
426 }
427 EXPORT_SYMBOL_GPL(cpdma_ctlr_dump);
428 
429 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
430 {
431 	unsigned long flags;
432 	int ret = 0, i;
433 
434 	if (!ctlr)
435 		return -EINVAL;
436 
437 	spin_lock_irqsave(&ctlr->lock, flags);
438 	if (ctlr->state != CPDMA_STATE_IDLE)
439 		cpdma_ctlr_stop(ctlr);
440 
441 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
442 		if (ctlr->channels[i])
443 			cpdma_chan_destroy(ctlr->channels[i]);
444 	}
445 
446 	cpdma_desc_pool_destroy(ctlr->pool);
447 	spin_unlock_irqrestore(&ctlr->lock, flags);
448 	kfree(ctlr);
449 	return ret;
450 }
451 EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);
452 
453 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
454 {
455 	unsigned long flags;
456 	int i, reg;
457 
458 	spin_lock_irqsave(&ctlr->lock, flags);
459 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
460 		spin_unlock_irqrestore(&ctlr->lock, flags);
461 		return -EINVAL;
462 	}
463 
464 	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
465 	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
466 
467 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
468 		if (ctlr->channels[i])
469 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
470 	}
471 
472 	spin_unlock_irqrestore(&ctlr->lock, flags);
473 	return 0;
474 }
475 
476 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr)
477 {
478 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, 0);
479 }
480 
481 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
482 				     cpdma_handler_fn handler)
483 {
484 	struct cpdma_chan *chan;
485 	int ret, offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
486 	unsigned long flags;
487 
488 	if (__chan_linear(chan_num) >= ctlr->num_chan)
489 		return NULL;
490 
491 	ret = -ENOMEM;
492 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
493 	if (!chan)
494 		goto err_chan_alloc;
495 
496 	spin_lock_irqsave(&ctlr->lock, flags);
497 	ret = -EBUSY;
498 	if (ctlr->channels[chan_num])
499 		goto err_chan_busy;
500 
501 	chan->ctlr	= ctlr;
502 	chan->state	= CPDMA_STATE_IDLE;
503 	chan->chan_num	= chan_num;
504 	chan->handler	= handler;
505 
506 	if (is_rx_chan(chan)) {
507 		chan->hdp	= ctlr->params.rxhdp + offset;
508 		chan->cp	= ctlr->params.rxcp + offset;
509 		chan->rxfree	= ctlr->params.rxfree + offset;
510 		chan->int_set	= CPDMA_RXINTMASKSET;
511 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
512 		chan->td	= CPDMA_RXTEARDOWN;
513 		chan->dir	= DMA_FROM_DEVICE;
514 	} else {
515 		chan->hdp	= ctlr->params.txhdp + offset;
516 		chan->cp	= ctlr->params.txcp + offset;
517 		chan->int_set	= CPDMA_TXINTMASKSET;
518 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
519 		chan->td	= CPDMA_TXTEARDOWN;
520 		chan->dir	= DMA_TO_DEVICE;
521 	}
522 	chan->mask = BIT(chan_linear(chan));
523 
524 	spin_lock_init(&chan->lock);
525 
526 	ctlr->channels[chan_num] = chan;
527 	spin_unlock_irqrestore(&ctlr->lock, flags);
528 	return chan;
529 
530 err_chan_busy:
531 	spin_unlock_irqrestore(&ctlr->lock, flags);
532 	kfree(chan);
533 err_chan_alloc:
534 	return ERR_PTR(ret);
535 }
536 EXPORT_SYMBOL_GPL(cpdma_chan_create);
537 
538 int cpdma_chan_destroy(struct cpdma_chan *chan)
539 {
540 	struct cpdma_ctlr *ctlr = chan->ctlr;
541 	unsigned long flags;
542 
543 	if (!chan)
544 		return -EINVAL;
545 
546 	spin_lock_irqsave(&ctlr->lock, flags);
547 	if (chan->state != CPDMA_STATE_IDLE)
548 		cpdma_chan_stop(chan);
549 	ctlr->channels[chan->chan_num] = NULL;
550 	spin_unlock_irqrestore(&ctlr->lock, flags);
551 	kfree(chan);
552 	return 0;
553 }
554 EXPORT_SYMBOL_GPL(cpdma_chan_destroy);
555 
556 int cpdma_chan_get_stats(struct cpdma_chan *chan,
557 			 struct cpdma_chan_stats *stats)
558 {
559 	unsigned long flags;
560 	if (!chan)
561 		return -EINVAL;
562 	spin_lock_irqsave(&chan->lock, flags);
563 	memcpy(stats, &chan->stats, sizeof(*stats));
564 	spin_unlock_irqrestore(&chan->lock, flags);
565 	return 0;
566 }
567 
568 int cpdma_chan_dump(struct cpdma_chan *chan)
569 {
570 	unsigned long flags;
571 	struct device *dev = chan->ctlr->dev;
572 
573 	spin_lock_irqsave(&chan->lock, flags);
574 
575 	dev_info(dev, "channel %d (%s %d) state %s",
576 		 chan->chan_num, is_rx_chan(chan) ? "rx" : "tx",
577 		 chan_linear(chan), cpdma_state_str[chan->state]);
578 	dev_info(dev, "\thdp: %x\n", chan_read(chan, hdp));
579 	dev_info(dev, "\tcp: %x\n", chan_read(chan, cp));
580 	if (chan->rxfree) {
581 		dev_info(dev, "\trxfree: %x\n",
582 			 chan_read(chan, rxfree));
583 	}
584 
585 	dev_info(dev, "\tstats head_enqueue: %d\n",
586 		 chan->stats.head_enqueue);
587 	dev_info(dev, "\tstats tail_enqueue: %d\n",
588 		 chan->stats.tail_enqueue);
589 	dev_info(dev, "\tstats pad_enqueue: %d\n",
590 		 chan->stats.pad_enqueue);
591 	dev_info(dev, "\tstats misqueued: %d\n",
592 		 chan->stats.misqueued);
593 	dev_info(dev, "\tstats desc_alloc_fail: %d\n",
594 		 chan->stats.desc_alloc_fail);
595 	dev_info(dev, "\tstats pad_alloc_fail: %d\n",
596 		 chan->stats.pad_alloc_fail);
597 	dev_info(dev, "\tstats runt_receive_buff: %d\n",
598 		 chan->stats.runt_receive_buff);
599 	dev_info(dev, "\tstats runt_transmit_buff: %d\n",
600 		 chan->stats.runt_transmit_buff);
601 	dev_info(dev, "\tstats empty_dequeue: %d\n",
602 		 chan->stats.empty_dequeue);
603 	dev_info(dev, "\tstats busy_dequeue: %d\n",
604 		 chan->stats.busy_dequeue);
605 	dev_info(dev, "\tstats good_dequeue: %d\n",
606 		 chan->stats.good_dequeue);
607 	dev_info(dev, "\tstats requeue: %d\n",
608 		 chan->stats.requeue);
609 	dev_info(dev, "\tstats teardown_dequeue: %d\n",
610 		 chan->stats.teardown_dequeue);
611 
612 	spin_unlock_irqrestore(&chan->lock, flags);
613 	return 0;
614 }
615 
616 static void __cpdma_chan_submit(struct cpdma_chan *chan,
617 				struct cpdma_desc __iomem *desc)
618 {
619 	struct cpdma_ctlr		*ctlr = chan->ctlr;
620 	struct cpdma_desc __iomem	*prev = chan->tail;
621 	struct cpdma_desc_pool		*pool = ctlr->pool;
622 	dma_addr_t			desc_dma;
623 	u32				mode;
624 
625 	desc_dma = desc_phys(pool, desc);
626 
627 	/* simple case - idle channel */
628 	if (!chan->head) {
629 		chan->stats.head_enqueue++;
630 		chan->head = desc;
631 		chan->tail = desc;
632 		if (chan->state == CPDMA_STATE_ACTIVE)
633 			chan_write(chan, hdp, desc_dma);
634 		return;
635 	}
636 
637 	/* first chain the descriptor at the tail of the list */
638 	desc_write(prev, hw_next, desc_dma);
639 	chan->tail = desc;
640 	chan->stats.tail_enqueue++;
641 
642 	/* next check if EOQ has been triggered already */
643 	mode = desc_read(prev, hw_mode);
644 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
645 	    (chan->state == CPDMA_STATE_ACTIVE)) {
646 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
647 		chan_write(chan, hdp, desc_dma);
648 		chan->stats.misqueued++;
649 	}
650 }
651 
652 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
653 		      int len, gfp_t gfp_mask)
654 {
655 	struct cpdma_ctlr		*ctlr = chan->ctlr;
656 	struct cpdma_desc __iomem	*desc;
657 	dma_addr_t			buffer;
658 	unsigned long			flags;
659 	u32				mode;
660 	int				ret = 0;
661 
662 	spin_lock_irqsave(&chan->lock, flags);
663 
664 	if (chan->state == CPDMA_STATE_TEARDOWN) {
665 		ret = -EINVAL;
666 		goto unlock_ret;
667 	}
668 
669 	desc = cpdma_desc_alloc(ctlr->pool, 1);
670 	if (!desc) {
671 		chan->stats.desc_alloc_fail++;
672 		ret = -ENOMEM;
673 		goto unlock_ret;
674 	}
675 
676 	if (len < ctlr->params.min_packet_size) {
677 		len = ctlr->params.min_packet_size;
678 		chan->stats.runt_transmit_buff++;
679 	}
680 
681 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
682 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
683 
684 	desc_write(desc, hw_next,   0);
685 	desc_write(desc, hw_buffer, buffer);
686 	desc_write(desc, hw_len,    len);
687 	desc_write(desc, hw_mode,   mode | len);
688 	desc_write(desc, sw_token,  token);
689 	desc_write(desc, sw_buffer, buffer);
690 	desc_write(desc, sw_len,    len);
691 
692 	__cpdma_chan_submit(chan, desc);
693 
694 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
695 		chan_write(chan, rxfree, 1);
696 
697 	chan->count++;
698 
699 unlock_ret:
700 	spin_unlock_irqrestore(&chan->lock, flags);
701 	return ret;
702 }
703 EXPORT_SYMBOL_GPL(cpdma_chan_submit);
704 
705 static void __cpdma_chan_free(struct cpdma_chan *chan,
706 			      struct cpdma_desc __iomem *desc,
707 			      int outlen, int status)
708 {
709 	struct cpdma_ctlr		*ctlr = chan->ctlr;
710 	struct cpdma_desc_pool		*pool = ctlr->pool;
711 	dma_addr_t			buff_dma;
712 	int				origlen;
713 	void				*token;
714 
715 	token      = (void *)desc_read(desc, sw_token);
716 	buff_dma   = desc_read(desc, sw_buffer);
717 	origlen    = desc_read(desc, sw_len);
718 
719 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
720 	cpdma_desc_free(pool, desc, 1);
721 	(*chan->handler)(token, outlen, status);
722 }
723 
724 static int __cpdma_chan_process(struct cpdma_chan *chan)
725 {
726 	struct cpdma_ctlr		*ctlr = chan->ctlr;
727 	struct cpdma_desc __iomem	*desc;
728 	int				status, outlen;
729 	struct cpdma_desc_pool		*pool = ctlr->pool;
730 	dma_addr_t			desc_dma;
731 	unsigned long			flags;
732 
733 	spin_lock_irqsave(&chan->lock, flags);
734 
735 	desc = chan->head;
736 	if (!desc) {
737 		chan->stats.empty_dequeue++;
738 		status = -ENOENT;
739 		goto unlock_ret;
740 	}
741 	desc_dma = desc_phys(pool, desc);
742 
743 	status	= __raw_readl(&desc->hw_mode);
744 	outlen	= status & 0x7ff;
745 	if (status & CPDMA_DESC_OWNER) {
746 		chan->stats.busy_dequeue++;
747 		status = -EBUSY;
748 		goto unlock_ret;
749 	}
750 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE);
751 
752 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
753 	chan_write(chan, cp, desc_dma);
754 	chan->count--;
755 	chan->stats.good_dequeue++;
756 
757 	if (status & CPDMA_DESC_EOQ) {
758 		chan->stats.requeue++;
759 		chan_write(chan, hdp, desc_phys(pool, chan->head));
760 	}
761 
762 	spin_unlock_irqrestore(&chan->lock, flags);
763 
764 	__cpdma_chan_free(chan, desc, outlen, status);
765 	return status;
766 
767 unlock_ret:
768 	spin_unlock_irqrestore(&chan->lock, flags);
769 	return status;
770 }
771 
772 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
773 {
774 	int used = 0, ret = 0;
775 
776 	if (chan->state != CPDMA_STATE_ACTIVE)
777 		return -EINVAL;
778 
779 	while (used < quota) {
780 		ret = __cpdma_chan_process(chan);
781 		if (ret < 0)
782 			break;
783 		used++;
784 	}
785 	return used;
786 }
787 EXPORT_SYMBOL_GPL(cpdma_chan_process);
788 
789 int cpdma_chan_start(struct cpdma_chan *chan)
790 {
791 	struct cpdma_ctlr	*ctlr = chan->ctlr;
792 	struct cpdma_desc_pool	*pool = ctlr->pool;
793 	unsigned long		flags;
794 
795 	spin_lock_irqsave(&chan->lock, flags);
796 	if (chan->state != CPDMA_STATE_IDLE) {
797 		spin_unlock_irqrestore(&chan->lock, flags);
798 		return -EBUSY;
799 	}
800 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
801 		spin_unlock_irqrestore(&chan->lock, flags);
802 		return -EINVAL;
803 	}
804 	dma_reg_write(ctlr, chan->int_set, chan->mask);
805 	chan->state = CPDMA_STATE_ACTIVE;
806 	if (chan->head) {
807 		chan_write(chan, hdp, desc_phys(pool, chan->head));
808 		if (chan->rxfree)
809 			chan_write(chan, rxfree, chan->count);
810 	}
811 
812 	spin_unlock_irqrestore(&chan->lock, flags);
813 	return 0;
814 }
815 EXPORT_SYMBOL_GPL(cpdma_chan_start);
816 
817 int cpdma_chan_stop(struct cpdma_chan *chan)
818 {
819 	struct cpdma_ctlr	*ctlr = chan->ctlr;
820 	struct cpdma_desc_pool	*pool = ctlr->pool;
821 	unsigned long		flags;
822 	int			ret;
823 	unsigned long		timeout;
824 
825 	spin_lock_irqsave(&chan->lock, flags);
826 	if (chan->state != CPDMA_STATE_ACTIVE) {
827 		spin_unlock_irqrestore(&chan->lock, flags);
828 		return -EINVAL;
829 	}
830 
831 	chan->state = CPDMA_STATE_TEARDOWN;
832 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
833 
834 	/* trigger teardown */
835 	dma_reg_write(ctlr, chan->td, chan_linear(chan));
836 
837 	/* wait for teardown complete */
838 	timeout = jiffies + HZ/10;	/* 100 msec */
839 	while (time_before(jiffies, timeout)) {
840 		u32 cp = chan_read(chan, cp);
841 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
842 			break;
843 		cpu_relax();
844 	}
845 	WARN_ON(!time_before(jiffies, timeout));
846 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
847 
848 	/* handle completed packets */
849 	spin_unlock_irqrestore(&chan->lock, flags);
850 	do {
851 		ret = __cpdma_chan_process(chan);
852 		if (ret < 0)
853 			break;
854 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
855 	spin_lock_irqsave(&chan->lock, flags);
856 
857 	/* remaining packets haven't been tx/rx'ed, clean them up */
858 	while (chan->head) {
859 		struct cpdma_desc __iomem *desc = chan->head;
860 		dma_addr_t next_dma;
861 
862 		next_dma = desc_read(desc, hw_next);
863 		chan->head = desc_from_phys(pool, next_dma);
864 		chan->stats.teardown_dequeue++;
865 
866 		/* issue callback without locks held */
867 		spin_unlock_irqrestore(&chan->lock, flags);
868 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
869 		spin_lock_irqsave(&chan->lock, flags);
870 	}
871 
872 	chan->state = CPDMA_STATE_IDLE;
873 	spin_unlock_irqrestore(&chan->lock, flags);
874 	return 0;
875 }
876 EXPORT_SYMBOL_GPL(cpdma_chan_stop);
877 
878 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
879 {
880 	unsigned long flags;
881 
882 	spin_lock_irqsave(&chan->lock, flags);
883 	if (chan->state != CPDMA_STATE_ACTIVE) {
884 		spin_unlock_irqrestore(&chan->lock, flags);
885 		return -EINVAL;
886 	}
887 
888 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
889 		      chan->mask);
890 	spin_unlock_irqrestore(&chan->lock, flags);
891 
892 	return 0;
893 }
894 
895 struct cpdma_control_info {
896 	u32		reg;
897 	u32		shift, mask;
898 	int		access;
899 #define ACCESS_RO	BIT(0)
900 #define ACCESS_WO	BIT(1)
901 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
902 };
903 
904 struct cpdma_control_info controls[] = {
905 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
906 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
907 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
908 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
909 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
910 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
911 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
912 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
913 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
914 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
915 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
916 };
917 
918 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
919 {
920 	unsigned long flags;
921 	struct cpdma_control_info *info = &controls[control];
922 	int ret;
923 
924 	spin_lock_irqsave(&ctlr->lock, flags);
925 
926 	ret = -ENOTSUPP;
927 	if (!ctlr->params.has_ext_regs)
928 		goto unlock_ret;
929 
930 	ret = -EINVAL;
931 	if (ctlr->state != CPDMA_STATE_ACTIVE)
932 		goto unlock_ret;
933 
934 	ret = -ENOENT;
935 	if (control < 0 || control >= ARRAY_SIZE(controls))
936 		goto unlock_ret;
937 
938 	ret = -EPERM;
939 	if ((info->access & ACCESS_RO) != ACCESS_RO)
940 		goto unlock_ret;
941 
942 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
943 
944 unlock_ret:
945 	spin_unlock_irqrestore(&ctlr->lock, flags);
946 	return ret;
947 }
948 
949 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
950 {
951 	unsigned long flags;
952 	struct cpdma_control_info *info = &controls[control];
953 	int ret;
954 	u32 val;
955 
956 	spin_lock_irqsave(&ctlr->lock, flags);
957 
958 	ret = -ENOTSUPP;
959 	if (!ctlr->params.has_ext_regs)
960 		goto unlock_ret;
961 
962 	ret = -EINVAL;
963 	if (ctlr->state != CPDMA_STATE_ACTIVE)
964 		goto unlock_ret;
965 
966 	ret = -ENOENT;
967 	if (control < 0 || control >= ARRAY_SIZE(controls))
968 		goto unlock_ret;
969 
970 	ret = -EPERM;
971 	if ((info->access & ACCESS_WO) != ACCESS_WO)
972 		goto unlock_ret;
973 
974 	val  = dma_reg_read(ctlr, info->reg);
975 	val &= ~(info->mask << info->shift);
976 	val |= (value & info->mask) << info->shift;
977 	dma_reg_write(ctlr, info->reg, val);
978 	ret = 0;
979 
980 unlock_ret:
981 	spin_unlock_irqrestore(&ctlr->lock, flags);
982 	return ret;
983 }
984