xref: /linux/drivers/net/ethernet/ti/davinci_cpdma.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 
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 	u32			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 	unsigned long		*bitmap;
91 	struct device		*dev;
92 	spinlock_t		lock;
93 };
94 
95 enum cpdma_state {
96 	CPDMA_STATE_IDLE,
97 	CPDMA_STATE_ACTIVE,
98 	CPDMA_STATE_TEARDOWN,
99 };
100 
101 static const char *cpdma_state_str[] = { "idle", "active", "teardown" };
102 
103 struct cpdma_ctlr {
104 	enum cpdma_state	state;
105 	struct cpdma_params	params;
106 	struct device		*dev;
107 	struct cpdma_desc_pool	*pool;
108 	spinlock_t		lock;
109 	struct cpdma_chan	*channels[2 * CPDMA_MAX_CHANNELS];
110 };
111 
112 struct cpdma_chan {
113 	struct cpdma_desc __iomem	*head, *tail;
114 	void __iomem			*hdp, *cp, *rxfree;
115 	enum cpdma_state		state;
116 	struct cpdma_ctlr		*ctlr;
117 	int				chan_num;
118 	spinlock_t			lock;
119 	int				count;
120 	u32				mask;
121 	cpdma_handler_fn		handler;
122 	enum dma_data_direction		dir;
123 	struct cpdma_chan_stats		stats;
124 	/* offsets into dmaregs */
125 	int	int_set, int_clear, td;
126 };
127 
128 /* The following make access to common cpdma_ctlr params more readable */
129 #define dmaregs		params.dmaregs
130 #define num_chan	params.num_chan
131 
132 /* various accessors */
133 #define dma_reg_read(ctlr, ofs)		__raw_readl((ctlr)->dmaregs + (ofs))
134 #define chan_read(chan, fld)		__raw_readl((chan)->fld)
135 #define desc_read(desc, fld)		__raw_readl(&(desc)->fld)
136 #define dma_reg_write(ctlr, ofs, v)	__raw_writel(v, (ctlr)->dmaregs + (ofs))
137 #define chan_write(chan, fld, v)	__raw_writel(v, (chan)->fld)
138 #define desc_write(desc, fld, v)	__raw_writel((u32)(v), &(desc)->fld)
139 
140 #define cpdma_desc_to_port(chan, mode, directed)			\
141 	do {								\
142 		if (!is_rx_chan(chan) && ((directed == 1) ||		\
143 					  (directed == 2)))		\
144 			mode |= (CPDMA_DESC_TO_PORT_EN |		\
145 				 (directed << CPDMA_TO_PORT_SHIFT));	\
146 	} while (0)
147 
148 /*
149  * Utility constructs for a cpdma descriptor pool.  Some devices (e.g. davinci
150  * emac) have dedicated on-chip memory for these descriptors.  Some other
151  * devices (e.g. cpsw switches) use plain old memory.  Descriptor pools
152  * abstract out these details
153  */
154 static struct cpdma_desc_pool *
155 cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
156 				int size, int align)
157 {
158 	int bitmap_size;
159 	struct cpdma_desc_pool *pool;
160 
161 	pool = devm_kzalloc(dev, sizeof(*pool), GFP_KERNEL);
162 	if (!pool)
163 		goto fail;
164 
165 	spin_lock_init(&pool->lock);
166 
167 	pool->dev	= dev;
168 	pool->mem_size	= size;
169 	pool->desc_size	= ALIGN(sizeof(struct cpdma_desc), align);
170 	pool->num_desc	= size / pool->desc_size;
171 
172 	bitmap_size  = (pool->num_desc / BITS_PER_LONG) * sizeof(long);
173 	pool->bitmap = devm_kzalloc(dev, bitmap_size, GFP_KERNEL);
174 	if (!pool->bitmap)
175 		goto fail;
176 
177 	if (phys) {
178 		pool->phys  = phys;
179 		pool->iomap = ioremap(phys, size);
180 		pool->hw_addr = hw_addr;
181 	} else {
182 		pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
183 						  GFP_KERNEL);
184 		pool->iomap = pool->cpumap;
185 		pool->hw_addr = pool->phys;
186 	}
187 
188 	if (pool->iomap)
189 		return pool;
190 fail:
191 	return NULL;
192 }
193 
194 static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
195 {
196 	unsigned long flags;
197 
198 	if (!pool)
199 		return;
200 
201 	spin_lock_irqsave(&pool->lock, flags);
202 	WARN_ON(pool->used_desc);
203 	if (pool->cpumap) {
204 		dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
205 				  pool->phys);
206 	} else {
207 		iounmap(pool->iomap);
208 	}
209 	spin_unlock_irqrestore(&pool->lock, flags);
210 }
211 
212 static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
213 		  struct cpdma_desc __iomem *desc)
214 {
215 	if (!desc)
216 		return 0;
217 	return pool->hw_addr + (__force long)desc - (__force long)pool->iomap;
218 }
219 
220 static inline struct cpdma_desc __iomem *
221 desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
222 {
223 	return dma ? pool->iomap + dma - pool->hw_addr : NULL;
224 }
225 
226 static struct cpdma_desc __iomem *
227 cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc, bool is_rx)
228 {
229 	unsigned long flags;
230 	int index;
231 	int desc_start;
232 	int desc_end;
233 	struct cpdma_desc __iomem *desc = NULL;
234 
235 	spin_lock_irqsave(&pool->lock, flags);
236 
237 	if (is_rx) {
238 		desc_start = 0;
239 		desc_end = pool->num_desc/2;
240 	 } else {
241 		desc_start = pool->num_desc/2;
242 		desc_end = pool->num_desc;
243 	}
244 
245 	index = bitmap_find_next_zero_area(pool->bitmap,
246 				desc_end, desc_start, num_desc, 0);
247 	if (index < desc_end) {
248 		bitmap_set(pool->bitmap, index, num_desc);
249 		desc = pool->iomap + pool->desc_size * index;
250 		pool->used_desc++;
251 	}
252 
253 	spin_unlock_irqrestore(&pool->lock, flags);
254 	return desc;
255 }
256 
257 static void cpdma_desc_free(struct cpdma_desc_pool *pool,
258 			    struct cpdma_desc __iomem *desc, int num_desc)
259 {
260 	unsigned long flags, index;
261 
262 	index = ((unsigned long)desc - (unsigned long)pool->iomap) /
263 		pool->desc_size;
264 	spin_lock_irqsave(&pool->lock, flags);
265 	bitmap_clear(pool->bitmap, index, num_desc);
266 	pool->used_desc--;
267 	spin_unlock_irqrestore(&pool->lock, flags);
268 }
269 
270 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
271 {
272 	struct cpdma_ctlr *ctlr;
273 
274 	ctlr = devm_kzalloc(params->dev, sizeof(*ctlr), GFP_KERNEL);
275 	if (!ctlr)
276 		return NULL;
277 
278 	ctlr->state = CPDMA_STATE_IDLE;
279 	ctlr->params = *params;
280 	ctlr->dev = params->dev;
281 	spin_lock_init(&ctlr->lock);
282 
283 	ctlr->pool = cpdma_desc_pool_create(ctlr->dev,
284 					    ctlr->params.desc_mem_phys,
285 					    ctlr->params.desc_hw_addr,
286 					    ctlr->params.desc_mem_size,
287 					    ctlr->params.desc_align);
288 	if (!ctlr->pool)
289 		return NULL;
290 
291 	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
292 		ctlr->num_chan = CPDMA_MAX_CHANNELS;
293 	return ctlr;
294 }
295 EXPORT_SYMBOL_GPL(cpdma_ctlr_create);
296 
297 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
298 {
299 	unsigned long flags;
300 	int i;
301 
302 	spin_lock_irqsave(&ctlr->lock, flags);
303 	if (ctlr->state != CPDMA_STATE_IDLE) {
304 		spin_unlock_irqrestore(&ctlr->lock, flags);
305 		return -EBUSY;
306 	}
307 
308 	if (ctlr->params.has_soft_reset) {
309 		unsigned timeout = 10 * 100;
310 
311 		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
312 		while (timeout) {
313 			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
314 				break;
315 			udelay(10);
316 			timeout--;
317 		}
318 		WARN_ON(!timeout);
319 	}
320 
321 	for (i = 0; i < ctlr->num_chan; i++) {
322 		__raw_writel(0, ctlr->params.txhdp + 4 * i);
323 		__raw_writel(0, ctlr->params.rxhdp + 4 * i);
324 		__raw_writel(0, ctlr->params.txcp + 4 * i);
325 		__raw_writel(0, ctlr->params.rxcp + 4 * i);
326 	}
327 
328 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
329 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
330 
331 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
332 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
333 
334 	ctlr->state = CPDMA_STATE_ACTIVE;
335 
336 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
337 		if (ctlr->channels[i])
338 			cpdma_chan_start(ctlr->channels[i]);
339 	}
340 	spin_unlock_irqrestore(&ctlr->lock, flags);
341 	return 0;
342 }
343 EXPORT_SYMBOL_GPL(cpdma_ctlr_start);
344 
345 int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
346 {
347 	unsigned long flags;
348 	int i;
349 
350 	spin_lock_irqsave(&ctlr->lock, flags);
351 	if (ctlr->state == CPDMA_STATE_TEARDOWN) {
352 		spin_unlock_irqrestore(&ctlr->lock, flags);
353 		return -EINVAL;
354 	}
355 
356 	ctlr->state = CPDMA_STATE_TEARDOWN;
357 
358 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
359 		if (ctlr->channels[i])
360 			cpdma_chan_stop(ctlr->channels[i]);
361 	}
362 
363 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
364 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
365 
366 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
367 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
368 
369 	ctlr->state = CPDMA_STATE_IDLE;
370 
371 	spin_unlock_irqrestore(&ctlr->lock, flags);
372 	return 0;
373 }
374 EXPORT_SYMBOL_GPL(cpdma_ctlr_stop);
375 
376 int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr)
377 {
378 	struct device *dev = ctlr->dev;
379 	unsigned long flags;
380 	int i;
381 
382 	spin_lock_irqsave(&ctlr->lock, flags);
383 
384 	dev_info(dev, "CPDMA: state: %s", cpdma_state_str[ctlr->state]);
385 
386 	dev_info(dev, "CPDMA: txidver: %x",
387 		 dma_reg_read(ctlr, CPDMA_TXIDVER));
388 	dev_info(dev, "CPDMA: txcontrol: %x",
389 		 dma_reg_read(ctlr, CPDMA_TXCONTROL));
390 	dev_info(dev, "CPDMA: txteardown: %x",
391 		 dma_reg_read(ctlr, CPDMA_TXTEARDOWN));
392 	dev_info(dev, "CPDMA: rxidver: %x",
393 		 dma_reg_read(ctlr, CPDMA_RXIDVER));
394 	dev_info(dev, "CPDMA: rxcontrol: %x",
395 		 dma_reg_read(ctlr, CPDMA_RXCONTROL));
396 	dev_info(dev, "CPDMA: softreset: %x",
397 		 dma_reg_read(ctlr, CPDMA_SOFTRESET));
398 	dev_info(dev, "CPDMA: rxteardown: %x",
399 		 dma_reg_read(ctlr, CPDMA_RXTEARDOWN));
400 	dev_info(dev, "CPDMA: txintstatraw: %x",
401 		 dma_reg_read(ctlr, CPDMA_TXINTSTATRAW));
402 	dev_info(dev, "CPDMA: txintstatmasked: %x",
403 		 dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED));
404 	dev_info(dev, "CPDMA: txintmaskset: %x",
405 		 dma_reg_read(ctlr, CPDMA_TXINTMASKSET));
406 	dev_info(dev, "CPDMA: txintmaskclear: %x",
407 		 dma_reg_read(ctlr, CPDMA_TXINTMASKCLEAR));
408 	dev_info(dev, "CPDMA: macinvector: %x",
409 		 dma_reg_read(ctlr, CPDMA_MACINVECTOR));
410 	dev_info(dev, "CPDMA: maceoivector: %x",
411 		 dma_reg_read(ctlr, CPDMA_MACEOIVECTOR));
412 	dev_info(dev, "CPDMA: rxintstatraw: %x",
413 		 dma_reg_read(ctlr, CPDMA_RXINTSTATRAW));
414 	dev_info(dev, "CPDMA: rxintstatmasked: %x",
415 		 dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED));
416 	dev_info(dev, "CPDMA: rxintmaskset: %x",
417 		 dma_reg_read(ctlr, CPDMA_RXINTMASKSET));
418 	dev_info(dev, "CPDMA: rxintmaskclear: %x",
419 		 dma_reg_read(ctlr, CPDMA_RXINTMASKCLEAR));
420 	dev_info(dev, "CPDMA: dmaintstatraw: %x",
421 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATRAW));
422 	dev_info(dev, "CPDMA: dmaintstatmasked: %x",
423 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATMASKED));
424 	dev_info(dev, "CPDMA: dmaintmaskset: %x",
425 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKSET));
426 	dev_info(dev, "CPDMA: dmaintmaskclear: %x",
427 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKCLEAR));
428 
429 	if (!ctlr->params.has_ext_regs) {
430 		dev_info(dev, "CPDMA: dmacontrol: %x",
431 			 dma_reg_read(ctlr, CPDMA_DMACONTROL));
432 		dev_info(dev, "CPDMA: dmastatus: %x",
433 			 dma_reg_read(ctlr, CPDMA_DMASTATUS));
434 		dev_info(dev, "CPDMA: rxbuffofs: %x",
435 			 dma_reg_read(ctlr, CPDMA_RXBUFFOFS));
436 	}
437 
438 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
439 		if (ctlr->channels[i])
440 			cpdma_chan_dump(ctlr->channels[i]);
441 
442 	spin_unlock_irqrestore(&ctlr->lock, flags);
443 	return 0;
444 }
445 EXPORT_SYMBOL_GPL(cpdma_ctlr_dump);
446 
447 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
448 {
449 	unsigned long flags;
450 	int ret = 0, i;
451 
452 	if (!ctlr)
453 		return -EINVAL;
454 
455 	spin_lock_irqsave(&ctlr->lock, flags);
456 	if (ctlr->state != CPDMA_STATE_IDLE)
457 		cpdma_ctlr_stop(ctlr);
458 
459 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
460 		cpdma_chan_destroy(ctlr->channels[i]);
461 
462 	cpdma_desc_pool_destroy(ctlr->pool);
463 	spin_unlock_irqrestore(&ctlr->lock, flags);
464 	return ret;
465 }
466 EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);
467 
468 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
469 {
470 	unsigned long flags;
471 	int i, reg;
472 
473 	spin_lock_irqsave(&ctlr->lock, flags);
474 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
475 		spin_unlock_irqrestore(&ctlr->lock, flags);
476 		return -EINVAL;
477 	}
478 
479 	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
480 	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
481 
482 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
483 		if (ctlr->channels[i])
484 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
485 	}
486 
487 	spin_unlock_irqrestore(&ctlr->lock, flags);
488 	return 0;
489 }
490 EXPORT_SYMBOL_GPL(cpdma_ctlr_int_ctrl);
491 
492 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
493 {
494 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
495 }
496 EXPORT_SYMBOL_GPL(cpdma_ctlr_eoi);
497 
498 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
499 				     cpdma_handler_fn handler)
500 {
501 	struct cpdma_chan *chan;
502 	int offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
503 	unsigned long flags;
504 
505 	if (__chan_linear(chan_num) >= ctlr->num_chan)
506 		return NULL;
507 
508 	chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
509 	if (!chan)
510 		return ERR_PTR(-ENOMEM);
511 
512 	spin_lock_irqsave(&ctlr->lock, flags);
513 	if (ctlr->channels[chan_num]) {
514 		spin_unlock_irqrestore(&ctlr->lock, flags);
515 		devm_kfree(ctlr->dev, chan);
516 		return ERR_PTR(-EBUSY);
517 	}
518 
519 	chan->ctlr	= ctlr;
520 	chan->state	= CPDMA_STATE_IDLE;
521 	chan->chan_num	= chan_num;
522 	chan->handler	= handler;
523 
524 	if (is_rx_chan(chan)) {
525 		chan->hdp	= ctlr->params.rxhdp + offset;
526 		chan->cp	= ctlr->params.rxcp + offset;
527 		chan->rxfree	= ctlr->params.rxfree + offset;
528 		chan->int_set	= CPDMA_RXINTMASKSET;
529 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
530 		chan->td	= CPDMA_RXTEARDOWN;
531 		chan->dir	= DMA_FROM_DEVICE;
532 	} else {
533 		chan->hdp	= ctlr->params.txhdp + offset;
534 		chan->cp	= ctlr->params.txcp + offset;
535 		chan->int_set	= CPDMA_TXINTMASKSET;
536 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
537 		chan->td	= CPDMA_TXTEARDOWN;
538 		chan->dir	= DMA_TO_DEVICE;
539 	}
540 	chan->mask = BIT(chan_linear(chan));
541 
542 	spin_lock_init(&chan->lock);
543 
544 	ctlr->channels[chan_num] = chan;
545 	spin_unlock_irqrestore(&ctlr->lock, flags);
546 	return chan;
547 }
548 EXPORT_SYMBOL_GPL(cpdma_chan_create);
549 
550 int cpdma_chan_destroy(struct cpdma_chan *chan)
551 {
552 	struct cpdma_ctlr *ctlr;
553 	unsigned long flags;
554 
555 	if (!chan)
556 		return -EINVAL;
557 	ctlr = chan->ctlr;
558 
559 	spin_lock_irqsave(&ctlr->lock, flags);
560 	if (chan->state != CPDMA_STATE_IDLE)
561 		cpdma_chan_stop(chan);
562 	ctlr->channels[chan->chan_num] = NULL;
563 	spin_unlock_irqrestore(&ctlr->lock, flags);
564 	kfree(chan);
565 	return 0;
566 }
567 EXPORT_SYMBOL_GPL(cpdma_chan_destroy);
568 
569 int cpdma_chan_get_stats(struct cpdma_chan *chan,
570 			 struct cpdma_chan_stats *stats)
571 {
572 	unsigned long flags;
573 	if (!chan)
574 		return -EINVAL;
575 	spin_lock_irqsave(&chan->lock, flags);
576 	memcpy(stats, &chan->stats, sizeof(*stats));
577 	spin_unlock_irqrestore(&chan->lock, flags);
578 	return 0;
579 }
580 EXPORT_SYMBOL_GPL(cpdma_chan_get_stats);
581 
582 int cpdma_chan_dump(struct cpdma_chan *chan)
583 {
584 	unsigned long flags;
585 	struct device *dev = chan->ctlr->dev;
586 
587 	spin_lock_irqsave(&chan->lock, flags);
588 
589 	dev_info(dev, "channel %d (%s %d) state %s",
590 		 chan->chan_num, is_rx_chan(chan) ? "rx" : "tx",
591 		 chan_linear(chan), cpdma_state_str[chan->state]);
592 	dev_info(dev, "\thdp: %x\n", chan_read(chan, hdp));
593 	dev_info(dev, "\tcp: %x\n", chan_read(chan, cp));
594 	if (chan->rxfree) {
595 		dev_info(dev, "\trxfree: %x\n",
596 			 chan_read(chan, rxfree));
597 	}
598 
599 	dev_info(dev, "\tstats head_enqueue: %d\n",
600 		 chan->stats.head_enqueue);
601 	dev_info(dev, "\tstats tail_enqueue: %d\n",
602 		 chan->stats.tail_enqueue);
603 	dev_info(dev, "\tstats pad_enqueue: %d\n",
604 		 chan->stats.pad_enqueue);
605 	dev_info(dev, "\tstats misqueued: %d\n",
606 		 chan->stats.misqueued);
607 	dev_info(dev, "\tstats desc_alloc_fail: %d\n",
608 		 chan->stats.desc_alloc_fail);
609 	dev_info(dev, "\tstats pad_alloc_fail: %d\n",
610 		 chan->stats.pad_alloc_fail);
611 	dev_info(dev, "\tstats runt_receive_buff: %d\n",
612 		 chan->stats.runt_receive_buff);
613 	dev_info(dev, "\tstats runt_transmit_buff: %d\n",
614 		 chan->stats.runt_transmit_buff);
615 	dev_info(dev, "\tstats empty_dequeue: %d\n",
616 		 chan->stats.empty_dequeue);
617 	dev_info(dev, "\tstats busy_dequeue: %d\n",
618 		 chan->stats.busy_dequeue);
619 	dev_info(dev, "\tstats good_dequeue: %d\n",
620 		 chan->stats.good_dequeue);
621 	dev_info(dev, "\tstats requeue: %d\n",
622 		 chan->stats.requeue);
623 	dev_info(dev, "\tstats teardown_dequeue: %d\n",
624 		 chan->stats.teardown_dequeue);
625 
626 	spin_unlock_irqrestore(&chan->lock, flags);
627 	return 0;
628 }
629 
630 static void __cpdma_chan_submit(struct cpdma_chan *chan,
631 				struct cpdma_desc __iomem *desc)
632 {
633 	struct cpdma_ctlr		*ctlr = chan->ctlr;
634 	struct cpdma_desc __iomem	*prev = chan->tail;
635 	struct cpdma_desc_pool		*pool = ctlr->pool;
636 	dma_addr_t			desc_dma;
637 	u32				mode;
638 
639 	desc_dma = desc_phys(pool, desc);
640 
641 	/* simple case - idle channel */
642 	if (!chan->head) {
643 		chan->stats.head_enqueue++;
644 		chan->head = desc;
645 		chan->tail = desc;
646 		if (chan->state == CPDMA_STATE_ACTIVE)
647 			chan_write(chan, hdp, desc_dma);
648 		return;
649 	}
650 
651 	/* first chain the descriptor at the tail of the list */
652 	desc_write(prev, hw_next, desc_dma);
653 	chan->tail = desc;
654 	chan->stats.tail_enqueue++;
655 
656 	/* next check if EOQ has been triggered already */
657 	mode = desc_read(prev, hw_mode);
658 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
659 	    (chan->state == CPDMA_STATE_ACTIVE)) {
660 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
661 		chan_write(chan, hdp, desc_dma);
662 		chan->stats.misqueued++;
663 	}
664 }
665 
666 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
667 		      int len, int directed)
668 {
669 	struct cpdma_ctlr		*ctlr = chan->ctlr;
670 	struct cpdma_desc __iomem	*desc;
671 	dma_addr_t			buffer;
672 	unsigned long			flags;
673 	u32				mode;
674 	int				ret = 0;
675 
676 	spin_lock_irqsave(&chan->lock, flags);
677 
678 	if (chan->state == CPDMA_STATE_TEARDOWN) {
679 		ret = -EINVAL;
680 		goto unlock_ret;
681 	}
682 
683 	desc = cpdma_desc_alloc(ctlr->pool, 1, is_rx_chan(chan));
684 	if (!desc) {
685 		chan->stats.desc_alloc_fail++;
686 		ret = -ENOMEM;
687 		goto unlock_ret;
688 	}
689 
690 	if (len < ctlr->params.min_packet_size) {
691 		len = ctlr->params.min_packet_size;
692 		chan->stats.runt_transmit_buff++;
693 	}
694 
695 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
696 	ret = dma_mapping_error(ctlr->dev, buffer);
697 	if (ret) {
698 		cpdma_desc_free(ctlr->pool, desc, 1);
699 		ret = -EINVAL;
700 		goto unlock_ret;
701 	}
702 
703 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
704 	cpdma_desc_to_port(chan, mode, directed);
705 
706 	desc_write(desc, hw_next,   0);
707 	desc_write(desc, hw_buffer, buffer);
708 	desc_write(desc, hw_len,    len);
709 	desc_write(desc, hw_mode,   mode | len);
710 	desc_write(desc, sw_token,  token);
711 	desc_write(desc, sw_buffer, buffer);
712 	desc_write(desc, sw_len,    len);
713 
714 	__cpdma_chan_submit(chan, desc);
715 
716 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
717 		chan_write(chan, rxfree, 1);
718 
719 	chan->count++;
720 
721 unlock_ret:
722 	spin_unlock_irqrestore(&chan->lock, flags);
723 	return ret;
724 }
725 EXPORT_SYMBOL_GPL(cpdma_chan_submit);
726 
727 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
728 {
729 	unsigned long flags;
730 	int index;
731 	bool ret;
732 	struct cpdma_ctlr	*ctlr = chan->ctlr;
733 	struct cpdma_desc_pool	*pool = ctlr->pool;
734 
735 	spin_lock_irqsave(&pool->lock, flags);
736 
737 	index = bitmap_find_next_zero_area(pool->bitmap,
738 				pool->num_desc, pool->num_desc/2, 1, 0);
739 
740 	if (index < pool->num_desc)
741 		ret = true;
742 	else
743 		ret = false;
744 
745 	spin_unlock_irqrestore(&pool->lock, flags);
746 	return ret;
747 }
748 EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc);
749 
750 static void __cpdma_chan_free(struct cpdma_chan *chan,
751 			      struct cpdma_desc __iomem *desc,
752 			      int outlen, int status)
753 {
754 	struct cpdma_ctlr		*ctlr = chan->ctlr;
755 	struct cpdma_desc_pool		*pool = ctlr->pool;
756 	dma_addr_t			buff_dma;
757 	int				origlen;
758 	void				*token;
759 
760 	token      = (void *)desc_read(desc, sw_token);
761 	buff_dma   = desc_read(desc, sw_buffer);
762 	origlen    = desc_read(desc, sw_len);
763 
764 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
765 	cpdma_desc_free(pool, desc, 1);
766 	(*chan->handler)(token, outlen, status);
767 }
768 
769 static int __cpdma_chan_process(struct cpdma_chan *chan)
770 {
771 	struct cpdma_ctlr		*ctlr = chan->ctlr;
772 	struct cpdma_desc __iomem	*desc;
773 	int				status, outlen;
774 	int				cb_status = 0;
775 	struct cpdma_desc_pool		*pool = ctlr->pool;
776 	dma_addr_t			desc_dma;
777 	unsigned long			flags;
778 
779 	spin_lock_irqsave(&chan->lock, flags);
780 
781 	desc = chan->head;
782 	if (!desc) {
783 		chan->stats.empty_dequeue++;
784 		status = -ENOENT;
785 		goto unlock_ret;
786 	}
787 	desc_dma = desc_phys(pool, desc);
788 
789 	status	= __raw_readl(&desc->hw_mode);
790 	outlen	= status & 0x7ff;
791 	if (status & CPDMA_DESC_OWNER) {
792 		chan->stats.busy_dequeue++;
793 		status = -EBUSY;
794 		goto unlock_ret;
795 	}
796 
797 	if (status & CPDMA_DESC_PASS_CRC)
798 		outlen -= CPDMA_DESC_CRC_LEN;
799 
800 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
801 			    CPDMA_DESC_PORT_MASK);
802 
803 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
804 	chan_write(chan, cp, desc_dma);
805 	chan->count--;
806 	chan->stats.good_dequeue++;
807 
808 	if (status & CPDMA_DESC_EOQ) {
809 		chan->stats.requeue++;
810 		chan_write(chan, hdp, desc_phys(pool, chan->head));
811 	}
812 
813 	spin_unlock_irqrestore(&chan->lock, flags);
814 	if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
815 		cb_status = -ENOSYS;
816 	else
817 		cb_status = status;
818 
819 	__cpdma_chan_free(chan, desc, outlen, cb_status);
820 	return status;
821 
822 unlock_ret:
823 	spin_unlock_irqrestore(&chan->lock, flags);
824 	return status;
825 }
826 
827 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
828 {
829 	int used = 0, ret = 0;
830 
831 	if (chan->state != CPDMA_STATE_ACTIVE)
832 		return -EINVAL;
833 
834 	while (used < quota) {
835 		ret = __cpdma_chan_process(chan);
836 		if (ret < 0)
837 			break;
838 		used++;
839 	}
840 	return used;
841 }
842 EXPORT_SYMBOL_GPL(cpdma_chan_process);
843 
844 int cpdma_chan_start(struct cpdma_chan *chan)
845 {
846 	struct cpdma_ctlr	*ctlr = chan->ctlr;
847 	struct cpdma_desc_pool	*pool = ctlr->pool;
848 	unsigned long		flags;
849 
850 	spin_lock_irqsave(&chan->lock, flags);
851 	if (chan->state != CPDMA_STATE_IDLE) {
852 		spin_unlock_irqrestore(&chan->lock, flags);
853 		return -EBUSY;
854 	}
855 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
856 		spin_unlock_irqrestore(&chan->lock, flags);
857 		return -EINVAL;
858 	}
859 	dma_reg_write(ctlr, chan->int_set, chan->mask);
860 	chan->state = CPDMA_STATE_ACTIVE;
861 	if (chan->head) {
862 		chan_write(chan, hdp, desc_phys(pool, chan->head));
863 		if (chan->rxfree)
864 			chan_write(chan, rxfree, chan->count);
865 	}
866 
867 	spin_unlock_irqrestore(&chan->lock, flags);
868 	return 0;
869 }
870 EXPORT_SYMBOL_GPL(cpdma_chan_start);
871 
872 int cpdma_chan_stop(struct cpdma_chan *chan)
873 {
874 	struct cpdma_ctlr	*ctlr = chan->ctlr;
875 	struct cpdma_desc_pool	*pool = ctlr->pool;
876 	unsigned long		flags;
877 	int			ret;
878 	unsigned		timeout;
879 
880 	spin_lock_irqsave(&chan->lock, flags);
881 	if (chan->state == CPDMA_STATE_TEARDOWN) {
882 		spin_unlock_irqrestore(&chan->lock, flags);
883 		return -EINVAL;
884 	}
885 
886 	chan->state = CPDMA_STATE_TEARDOWN;
887 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
888 
889 	/* trigger teardown */
890 	dma_reg_write(ctlr, chan->td, chan_linear(chan));
891 
892 	/* wait for teardown complete */
893 	timeout = 100 * 100; /* 100 ms */
894 	while (timeout) {
895 		u32 cp = chan_read(chan, cp);
896 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
897 			break;
898 		udelay(10);
899 		timeout--;
900 	}
901 	WARN_ON(!timeout);
902 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
903 
904 	/* handle completed packets */
905 	spin_unlock_irqrestore(&chan->lock, flags);
906 	do {
907 		ret = __cpdma_chan_process(chan);
908 		if (ret < 0)
909 			break;
910 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
911 	spin_lock_irqsave(&chan->lock, flags);
912 
913 	/* remaining packets haven't been tx/rx'ed, clean them up */
914 	while (chan->head) {
915 		struct cpdma_desc __iomem *desc = chan->head;
916 		dma_addr_t next_dma;
917 
918 		next_dma = desc_read(desc, hw_next);
919 		chan->head = desc_from_phys(pool, next_dma);
920 		chan->count--;
921 		chan->stats.teardown_dequeue++;
922 
923 		/* issue callback without locks held */
924 		spin_unlock_irqrestore(&chan->lock, flags);
925 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
926 		spin_lock_irqsave(&chan->lock, flags);
927 	}
928 
929 	chan->state = CPDMA_STATE_IDLE;
930 	spin_unlock_irqrestore(&chan->lock, flags);
931 	return 0;
932 }
933 EXPORT_SYMBOL_GPL(cpdma_chan_stop);
934 
935 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
936 {
937 	unsigned long flags;
938 
939 	spin_lock_irqsave(&chan->lock, flags);
940 	if (chan->state != CPDMA_STATE_ACTIVE) {
941 		spin_unlock_irqrestore(&chan->lock, flags);
942 		return -EINVAL;
943 	}
944 
945 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
946 		      chan->mask);
947 	spin_unlock_irqrestore(&chan->lock, flags);
948 
949 	return 0;
950 }
951 
952 struct cpdma_control_info {
953 	u32		reg;
954 	u32		shift, mask;
955 	int		access;
956 #define ACCESS_RO	BIT(0)
957 #define ACCESS_WO	BIT(1)
958 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
959 };
960 
961 static struct cpdma_control_info controls[] = {
962 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
963 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
964 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
965 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
966 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
967 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
968 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
969 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
970 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
971 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
972 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
973 };
974 
975 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
976 {
977 	unsigned long flags;
978 	struct cpdma_control_info *info = &controls[control];
979 	int ret;
980 
981 	spin_lock_irqsave(&ctlr->lock, flags);
982 
983 	ret = -ENOTSUPP;
984 	if (!ctlr->params.has_ext_regs)
985 		goto unlock_ret;
986 
987 	ret = -EINVAL;
988 	if (ctlr->state != CPDMA_STATE_ACTIVE)
989 		goto unlock_ret;
990 
991 	ret = -ENOENT;
992 	if (control < 0 || control >= ARRAY_SIZE(controls))
993 		goto unlock_ret;
994 
995 	ret = -EPERM;
996 	if ((info->access & ACCESS_RO) != ACCESS_RO)
997 		goto unlock_ret;
998 
999 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
1000 
1001 unlock_ret:
1002 	spin_unlock_irqrestore(&ctlr->lock, flags);
1003 	return ret;
1004 }
1005 
1006 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
1007 {
1008 	unsigned long flags;
1009 	struct cpdma_control_info *info = &controls[control];
1010 	int ret;
1011 	u32 val;
1012 
1013 	spin_lock_irqsave(&ctlr->lock, flags);
1014 
1015 	ret = -ENOTSUPP;
1016 	if (!ctlr->params.has_ext_regs)
1017 		goto unlock_ret;
1018 
1019 	ret = -EINVAL;
1020 	if (ctlr->state != CPDMA_STATE_ACTIVE)
1021 		goto unlock_ret;
1022 
1023 	ret = -ENOENT;
1024 	if (control < 0 || control >= ARRAY_SIZE(controls))
1025 		goto unlock_ret;
1026 
1027 	ret = -EPERM;
1028 	if ((info->access & ACCESS_WO) != ACCESS_WO)
1029 		goto unlock_ret;
1030 
1031 	val  = dma_reg_read(ctlr, info->reg);
1032 	val &= ~(info->mask << info->shift);
1033 	val |= (value & info->mask) << info->shift;
1034 	dma_reg_write(ctlr, info->reg, val);
1035 	ret = 0;
1036 
1037 unlock_ret:
1038 	spin_unlock_irqrestore(&ctlr->lock, flags);
1039 	return ret;
1040 }
1041 EXPORT_SYMBOL_GPL(cpdma_control_set);
1042 
1043 MODULE_LICENSE("GPL");
1044