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