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 	u32			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 = kzalloc(sizeof(*pool), GFP_KERNEL);
162 	if (!pool)
163 		return NULL;
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 = kzalloc(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 
191 fail:
192 	kfree(pool->bitmap);
193 	kfree(pool);
194 	return NULL;
195 }
196 
197 static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
198 {
199 	unsigned long flags;
200 
201 	if (!pool)
202 		return;
203 
204 	spin_lock_irqsave(&pool->lock, flags);
205 	WARN_ON(pool->used_desc);
206 	kfree(pool->bitmap);
207 	if (pool->cpumap) {
208 		dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
209 				  pool->phys);
210 	} else {
211 		iounmap(pool->iomap);
212 	}
213 	spin_unlock_irqrestore(&pool->lock, flags);
214 	kfree(pool);
215 }
216 
217 static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
218 		  struct cpdma_desc __iomem *desc)
219 {
220 	if (!desc)
221 		return 0;
222 	return pool->hw_addr + (__force dma_addr_t)desc -
223 			    (__force dma_addr_t)pool->iomap;
224 }
225 
226 static inline struct cpdma_desc __iomem *
227 desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
228 {
229 	return dma ? pool->iomap + dma - pool->hw_addr : NULL;
230 }
231 
232 static struct cpdma_desc __iomem *
233 cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc, bool is_rx)
234 {
235 	unsigned long flags;
236 	int index;
237 	int desc_start;
238 	int desc_end;
239 	struct cpdma_desc __iomem *desc = NULL;
240 
241 	spin_lock_irqsave(&pool->lock, flags);
242 
243 	if (is_rx) {
244 		desc_start = 0;
245 		desc_end = pool->num_desc/2;
246 	 } else {
247 		desc_start = pool->num_desc/2;
248 		desc_end = pool->num_desc;
249 	}
250 
251 	index = bitmap_find_next_zero_area(pool->bitmap,
252 				desc_end, desc_start, num_desc, 0);
253 	if (index < desc_end) {
254 		bitmap_set(pool->bitmap, index, num_desc);
255 		desc = pool->iomap + pool->desc_size * index;
256 		pool->used_desc++;
257 	}
258 
259 	spin_unlock_irqrestore(&pool->lock, flags);
260 	return desc;
261 }
262 
263 static void cpdma_desc_free(struct cpdma_desc_pool *pool,
264 			    struct cpdma_desc __iomem *desc, int num_desc)
265 {
266 	unsigned long flags, index;
267 
268 	index = ((unsigned long)desc - (unsigned long)pool->iomap) /
269 		pool->desc_size;
270 	spin_lock_irqsave(&pool->lock, flags);
271 	bitmap_clear(pool->bitmap, index, num_desc);
272 	pool->used_desc--;
273 	spin_unlock_irqrestore(&pool->lock, flags);
274 }
275 
276 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
277 {
278 	struct cpdma_ctlr *ctlr;
279 
280 	ctlr = kzalloc(sizeof(*ctlr), GFP_KERNEL);
281 	if (!ctlr)
282 		return NULL;
283 
284 	ctlr->state = CPDMA_STATE_IDLE;
285 	ctlr->params = *params;
286 	ctlr->dev = params->dev;
287 	spin_lock_init(&ctlr->lock);
288 
289 	ctlr->pool = cpdma_desc_pool_create(ctlr->dev,
290 					    ctlr->params.desc_mem_phys,
291 					    ctlr->params.desc_hw_addr,
292 					    ctlr->params.desc_mem_size,
293 					    ctlr->params.desc_align);
294 	if (!ctlr->pool) {
295 		kfree(ctlr);
296 		return NULL;
297 	}
298 
299 	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
300 		ctlr->num_chan = CPDMA_MAX_CHANNELS;
301 	return ctlr;
302 }
303 EXPORT_SYMBOL_GPL(cpdma_ctlr_create);
304 
305 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
306 {
307 	unsigned long flags;
308 	int i;
309 
310 	spin_lock_irqsave(&ctlr->lock, flags);
311 	if (ctlr->state != CPDMA_STATE_IDLE) {
312 		spin_unlock_irqrestore(&ctlr->lock, flags);
313 		return -EBUSY;
314 	}
315 
316 	if (ctlr->params.has_soft_reset) {
317 		unsigned timeout = 10 * 100;
318 
319 		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
320 		while (timeout) {
321 			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
322 				break;
323 			udelay(10);
324 			timeout--;
325 		}
326 		WARN_ON(!timeout);
327 	}
328 
329 	for (i = 0; i < ctlr->num_chan; i++) {
330 		__raw_writel(0, ctlr->params.txhdp + 4 * i);
331 		__raw_writel(0, ctlr->params.rxhdp + 4 * i);
332 		__raw_writel(0, ctlr->params.txcp + 4 * i);
333 		__raw_writel(0, ctlr->params.rxcp + 4 * i);
334 	}
335 
336 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
337 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
338 
339 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
340 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
341 
342 	ctlr->state = CPDMA_STATE_ACTIVE;
343 
344 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
345 		if (ctlr->channels[i])
346 			cpdma_chan_start(ctlr->channels[i]);
347 	}
348 	spin_unlock_irqrestore(&ctlr->lock, flags);
349 	return 0;
350 }
351 EXPORT_SYMBOL_GPL(cpdma_ctlr_start);
352 
353 int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
354 {
355 	unsigned long flags;
356 	int i;
357 
358 	spin_lock_irqsave(&ctlr->lock, flags);
359 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
360 		spin_unlock_irqrestore(&ctlr->lock, flags);
361 		return -EINVAL;
362 	}
363 
364 	ctlr->state = CPDMA_STATE_TEARDOWN;
365 
366 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
367 		if (ctlr->channels[i])
368 			cpdma_chan_stop(ctlr->channels[i]);
369 	}
370 
371 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
372 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
373 
374 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
375 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
376 
377 	ctlr->state = CPDMA_STATE_IDLE;
378 
379 	spin_unlock_irqrestore(&ctlr->lock, flags);
380 	return 0;
381 }
382 EXPORT_SYMBOL_GPL(cpdma_ctlr_stop);
383 
384 int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr)
385 {
386 	struct device *dev = ctlr->dev;
387 	unsigned long flags;
388 	int i;
389 
390 	spin_lock_irqsave(&ctlr->lock, flags);
391 
392 	dev_info(dev, "CPDMA: state: %s", cpdma_state_str[ctlr->state]);
393 
394 	dev_info(dev, "CPDMA: txidver: %x",
395 		 dma_reg_read(ctlr, CPDMA_TXIDVER));
396 	dev_info(dev, "CPDMA: txcontrol: %x",
397 		 dma_reg_read(ctlr, CPDMA_TXCONTROL));
398 	dev_info(dev, "CPDMA: txteardown: %x",
399 		 dma_reg_read(ctlr, CPDMA_TXTEARDOWN));
400 	dev_info(dev, "CPDMA: rxidver: %x",
401 		 dma_reg_read(ctlr, CPDMA_RXIDVER));
402 	dev_info(dev, "CPDMA: rxcontrol: %x",
403 		 dma_reg_read(ctlr, CPDMA_RXCONTROL));
404 	dev_info(dev, "CPDMA: softreset: %x",
405 		 dma_reg_read(ctlr, CPDMA_SOFTRESET));
406 	dev_info(dev, "CPDMA: rxteardown: %x",
407 		 dma_reg_read(ctlr, CPDMA_RXTEARDOWN));
408 	dev_info(dev, "CPDMA: txintstatraw: %x",
409 		 dma_reg_read(ctlr, CPDMA_TXINTSTATRAW));
410 	dev_info(dev, "CPDMA: txintstatmasked: %x",
411 		 dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED));
412 	dev_info(dev, "CPDMA: txintmaskset: %x",
413 		 dma_reg_read(ctlr, CPDMA_TXINTMASKSET));
414 	dev_info(dev, "CPDMA: txintmaskclear: %x",
415 		 dma_reg_read(ctlr, CPDMA_TXINTMASKCLEAR));
416 	dev_info(dev, "CPDMA: macinvector: %x",
417 		 dma_reg_read(ctlr, CPDMA_MACINVECTOR));
418 	dev_info(dev, "CPDMA: maceoivector: %x",
419 		 dma_reg_read(ctlr, CPDMA_MACEOIVECTOR));
420 	dev_info(dev, "CPDMA: rxintstatraw: %x",
421 		 dma_reg_read(ctlr, CPDMA_RXINTSTATRAW));
422 	dev_info(dev, "CPDMA: rxintstatmasked: %x",
423 		 dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED));
424 	dev_info(dev, "CPDMA: rxintmaskset: %x",
425 		 dma_reg_read(ctlr, CPDMA_RXINTMASKSET));
426 	dev_info(dev, "CPDMA: rxintmaskclear: %x",
427 		 dma_reg_read(ctlr, CPDMA_RXINTMASKCLEAR));
428 	dev_info(dev, "CPDMA: dmaintstatraw: %x",
429 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATRAW));
430 	dev_info(dev, "CPDMA: dmaintstatmasked: %x",
431 		 dma_reg_read(ctlr, CPDMA_DMAINTSTATMASKED));
432 	dev_info(dev, "CPDMA: dmaintmaskset: %x",
433 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKSET));
434 	dev_info(dev, "CPDMA: dmaintmaskclear: %x",
435 		 dma_reg_read(ctlr, CPDMA_DMAINTMASKCLEAR));
436 
437 	if (!ctlr->params.has_ext_regs) {
438 		dev_info(dev, "CPDMA: dmacontrol: %x",
439 			 dma_reg_read(ctlr, CPDMA_DMACONTROL));
440 		dev_info(dev, "CPDMA: dmastatus: %x",
441 			 dma_reg_read(ctlr, CPDMA_DMASTATUS));
442 		dev_info(dev, "CPDMA: rxbuffofs: %x",
443 			 dma_reg_read(ctlr, CPDMA_RXBUFFOFS));
444 	}
445 
446 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
447 		if (ctlr->channels[i])
448 			cpdma_chan_dump(ctlr->channels[i]);
449 
450 	spin_unlock_irqrestore(&ctlr->lock, flags);
451 	return 0;
452 }
453 EXPORT_SYMBOL_GPL(cpdma_ctlr_dump);
454 
455 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
456 {
457 	unsigned long flags;
458 	int ret = 0, i;
459 
460 	if (!ctlr)
461 		return -EINVAL;
462 
463 	spin_lock_irqsave(&ctlr->lock, flags);
464 	if (ctlr->state != CPDMA_STATE_IDLE)
465 		cpdma_ctlr_stop(ctlr);
466 
467 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
468 		cpdma_chan_destroy(ctlr->channels[i]);
469 
470 	cpdma_desc_pool_destroy(ctlr->pool);
471 	spin_unlock_irqrestore(&ctlr->lock, flags);
472 	kfree(ctlr);
473 	return ret;
474 }
475 EXPORT_SYMBOL_GPL(cpdma_ctlr_destroy);
476 
477 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
478 {
479 	unsigned long flags;
480 	int i, reg;
481 
482 	spin_lock_irqsave(&ctlr->lock, flags);
483 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
484 		spin_unlock_irqrestore(&ctlr->lock, flags);
485 		return -EINVAL;
486 	}
487 
488 	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
489 	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
490 
491 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
492 		if (ctlr->channels[i])
493 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
494 	}
495 
496 	spin_unlock_irqrestore(&ctlr->lock, flags);
497 	return 0;
498 }
499 EXPORT_SYMBOL_GPL(cpdma_ctlr_int_ctrl);
500 
501 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
502 {
503 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
504 }
505 EXPORT_SYMBOL_GPL(cpdma_ctlr_eoi);
506 
507 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
508 				     cpdma_handler_fn handler)
509 {
510 	struct cpdma_chan *chan;
511 	int ret, offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
512 	unsigned long flags;
513 
514 	if (__chan_linear(chan_num) >= ctlr->num_chan)
515 		return NULL;
516 
517 	ret = -ENOMEM;
518 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
519 	if (!chan)
520 		goto err_chan_alloc;
521 
522 	spin_lock_irqsave(&ctlr->lock, flags);
523 	ret = -EBUSY;
524 	if (ctlr->channels[chan_num])
525 		goto err_chan_busy;
526 
527 	chan->ctlr	= ctlr;
528 	chan->state	= CPDMA_STATE_IDLE;
529 	chan->chan_num	= chan_num;
530 	chan->handler	= handler;
531 
532 	if (is_rx_chan(chan)) {
533 		chan->hdp	= ctlr->params.rxhdp + offset;
534 		chan->cp	= ctlr->params.rxcp + offset;
535 		chan->rxfree	= ctlr->params.rxfree + offset;
536 		chan->int_set	= CPDMA_RXINTMASKSET;
537 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
538 		chan->td	= CPDMA_RXTEARDOWN;
539 		chan->dir	= DMA_FROM_DEVICE;
540 	} else {
541 		chan->hdp	= ctlr->params.txhdp + offset;
542 		chan->cp	= ctlr->params.txcp + offset;
543 		chan->int_set	= CPDMA_TXINTMASKSET;
544 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
545 		chan->td	= CPDMA_TXTEARDOWN;
546 		chan->dir	= DMA_TO_DEVICE;
547 	}
548 	chan->mask = BIT(chan_linear(chan));
549 
550 	spin_lock_init(&chan->lock);
551 
552 	ctlr->channels[chan_num] = chan;
553 	spin_unlock_irqrestore(&ctlr->lock, flags);
554 	return chan;
555 
556 err_chan_busy:
557 	spin_unlock_irqrestore(&ctlr->lock, flags);
558 	kfree(chan);
559 err_chan_alloc:
560 	return ERR_PTR(ret);
561 }
562 EXPORT_SYMBOL_GPL(cpdma_chan_create);
563 
564 int cpdma_chan_destroy(struct cpdma_chan *chan)
565 {
566 	struct cpdma_ctlr *ctlr;
567 	unsigned long flags;
568 
569 	if (!chan)
570 		return -EINVAL;
571 	ctlr = chan->ctlr;
572 
573 	spin_lock_irqsave(&ctlr->lock, flags);
574 	if (chan->state != CPDMA_STATE_IDLE)
575 		cpdma_chan_stop(chan);
576 	ctlr->channels[chan->chan_num] = NULL;
577 	spin_unlock_irqrestore(&ctlr->lock, flags);
578 	kfree(chan);
579 	return 0;
580 }
581 EXPORT_SYMBOL_GPL(cpdma_chan_destroy);
582 
583 int cpdma_chan_get_stats(struct cpdma_chan *chan,
584 			 struct cpdma_chan_stats *stats)
585 {
586 	unsigned long flags;
587 	if (!chan)
588 		return -EINVAL;
589 	spin_lock_irqsave(&chan->lock, flags);
590 	memcpy(stats, &chan->stats, sizeof(*stats));
591 	spin_unlock_irqrestore(&chan->lock, flags);
592 	return 0;
593 }
594 EXPORT_SYMBOL_GPL(cpdma_chan_get_stats);
595 
596 int cpdma_chan_dump(struct cpdma_chan *chan)
597 {
598 	unsigned long flags;
599 	struct device *dev = chan->ctlr->dev;
600 
601 	spin_lock_irqsave(&chan->lock, flags);
602 
603 	dev_info(dev, "channel %d (%s %d) state %s",
604 		 chan->chan_num, is_rx_chan(chan) ? "rx" : "tx",
605 		 chan_linear(chan), cpdma_state_str[chan->state]);
606 	dev_info(dev, "\thdp: %x\n", chan_read(chan, hdp));
607 	dev_info(dev, "\tcp: %x\n", chan_read(chan, cp));
608 	if (chan->rxfree) {
609 		dev_info(dev, "\trxfree: %x\n",
610 			 chan_read(chan, rxfree));
611 	}
612 
613 	dev_info(dev, "\tstats head_enqueue: %d\n",
614 		 chan->stats.head_enqueue);
615 	dev_info(dev, "\tstats tail_enqueue: %d\n",
616 		 chan->stats.tail_enqueue);
617 	dev_info(dev, "\tstats pad_enqueue: %d\n",
618 		 chan->stats.pad_enqueue);
619 	dev_info(dev, "\tstats misqueued: %d\n",
620 		 chan->stats.misqueued);
621 	dev_info(dev, "\tstats desc_alloc_fail: %d\n",
622 		 chan->stats.desc_alloc_fail);
623 	dev_info(dev, "\tstats pad_alloc_fail: %d\n",
624 		 chan->stats.pad_alloc_fail);
625 	dev_info(dev, "\tstats runt_receive_buff: %d\n",
626 		 chan->stats.runt_receive_buff);
627 	dev_info(dev, "\tstats runt_transmit_buff: %d\n",
628 		 chan->stats.runt_transmit_buff);
629 	dev_info(dev, "\tstats empty_dequeue: %d\n",
630 		 chan->stats.empty_dequeue);
631 	dev_info(dev, "\tstats busy_dequeue: %d\n",
632 		 chan->stats.busy_dequeue);
633 	dev_info(dev, "\tstats good_dequeue: %d\n",
634 		 chan->stats.good_dequeue);
635 	dev_info(dev, "\tstats requeue: %d\n",
636 		 chan->stats.requeue);
637 	dev_info(dev, "\tstats teardown_dequeue: %d\n",
638 		 chan->stats.teardown_dequeue);
639 
640 	spin_unlock_irqrestore(&chan->lock, flags);
641 	return 0;
642 }
643 
644 static void __cpdma_chan_submit(struct cpdma_chan *chan,
645 				struct cpdma_desc __iomem *desc)
646 {
647 	struct cpdma_ctlr		*ctlr = chan->ctlr;
648 	struct cpdma_desc __iomem	*prev = chan->tail;
649 	struct cpdma_desc_pool		*pool = ctlr->pool;
650 	dma_addr_t			desc_dma;
651 	u32				mode;
652 
653 	desc_dma = desc_phys(pool, desc);
654 
655 	/* simple case - idle channel */
656 	if (!chan->head) {
657 		chan->stats.head_enqueue++;
658 		chan->head = desc;
659 		chan->tail = desc;
660 		if (chan->state == CPDMA_STATE_ACTIVE)
661 			chan_write(chan, hdp, desc_dma);
662 		return;
663 	}
664 
665 	/* first chain the descriptor at the tail of the list */
666 	desc_write(prev, hw_next, desc_dma);
667 	chan->tail = desc;
668 	chan->stats.tail_enqueue++;
669 
670 	/* next check if EOQ has been triggered already */
671 	mode = desc_read(prev, hw_mode);
672 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
673 	    (chan->state == CPDMA_STATE_ACTIVE)) {
674 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
675 		chan_write(chan, hdp, desc_dma);
676 		chan->stats.misqueued++;
677 	}
678 }
679 
680 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
681 		      int len, int directed)
682 {
683 	struct cpdma_ctlr		*ctlr = chan->ctlr;
684 	struct cpdma_desc __iomem	*desc;
685 	dma_addr_t			buffer;
686 	unsigned long			flags;
687 	u32				mode;
688 	int				ret = 0;
689 
690 	spin_lock_irqsave(&chan->lock, flags);
691 
692 	if (chan->state == CPDMA_STATE_TEARDOWN) {
693 		ret = -EINVAL;
694 		goto unlock_ret;
695 	}
696 
697 	desc = cpdma_desc_alloc(ctlr->pool, 1, is_rx_chan(chan));
698 	if (!desc) {
699 		chan->stats.desc_alloc_fail++;
700 		ret = -ENOMEM;
701 		goto unlock_ret;
702 	}
703 
704 	if (len < ctlr->params.min_packet_size) {
705 		len = ctlr->params.min_packet_size;
706 		chan->stats.runt_transmit_buff++;
707 	}
708 
709 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
710 	ret = dma_mapping_error(ctlr->dev, buffer);
711 	if (ret) {
712 		cpdma_desc_free(ctlr->pool, desc, 1);
713 		ret = -EINVAL;
714 		goto unlock_ret;
715 	}
716 
717 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
718 	cpdma_desc_to_port(chan, mode, directed);
719 
720 	desc_write(desc, hw_next,   0);
721 	desc_write(desc, hw_buffer, buffer);
722 	desc_write(desc, hw_len,    len);
723 	desc_write(desc, hw_mode,   mode | len);
724 	desc_write(desc, sw_token,  token);
725 	desc_write(desc, sw_buffer, buffer);
726 	desc_write(desc, sw_len,    len);
727 
728 	__cpdma_chan_submit(chan, desc);
729 
730 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
731 		chan_write(chan, rxfree, 1);
732 
733 	chan->count++;
734 
735 unlock_ret:
736 	spin_unlock_irqrestore(&chan->lock, flags);
737 	return ret;
738 }
739 EXPORT_SYMBOL_GPL(cpdma_chan_submit);
740 
741 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
742 {
743 	unsigned long flags;
744 	int index;
745 	bool ret;
746 	struct cpdma_ctlr	*ctlr = chan->ctlr;
747 	struct cpdma_desc_pool	*pool = ctlr->pool;
748 
749 	spin_lock_irqsave(&pool->lock, flags);
750 
751 	index = bitmap_find_next_zero_area(pool->bitmap,
752 				pool->num_desc, pool->num_desc/2, 1, 0);
753 
754 	if (index < pool->num_desc)
755 		ret = true;
756 	else
757 		ret = false;
758 
759 	spin_unlock_irqrestore(&pool->lock, flags);
760 	return ret;
761 }
762 EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc);
763 
764 static void __cpdma_chan_free(struct cpdma_chan *chan,
765 			      struct cpdma_desc __iomem *desc,
766 			      int outlen, int status)
767 {
768 	struct cpdma_ctlr		*ctlr = chan->ctlr;
769 	struct cpdma_desc_pool		*pool = ctlr->pool;
770 	dma_addr_t			buff_dma;
771 	int				origlen;
772 	void				*token;
773 
774 	token      = (void *)desc_read(desc, sw_token);
775 	buff_dma   = desc_read(desc, sw_buffer);
776 	origlen    = desc_read(desc, sw_len);
777 
778 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
779 	cpdma_desc_free(pool, desc, 1);
780 	(*chan->handler)(token, outlen, status);
781 }
782 
783 static int __cpdma_chan_process(struct cpdma_chan *chan)
784 {
785 	struct cpdma_ctlr		*ctlr = chan->ctlr;
786 	struct cpdma_desc __iomem	*desc;
787 	int				status, outlen;
788 	int				cb_status = 0;
789 	struct cpdma_desc_pool		*pool = ctlr->pool;
790 	dma_addr_t			desc_dma;
791 	unsigned long			flags;
792 
793 	spin_lock_irqsave(&chan->lock, flags);
794 
795 	desc = chan->head;
796 	if (!desc) {
797 		chan->stats.empty_dequeue++;
798 		status = -ENOENT;
799 		goto unlock_ret;
800 	}
801 	desc_dma = desc_phys(pool, desc);
802 
803 	status	= __raw_readl(&desc->hw_mode);
804 	outlen	= status & 0x7ff;
805 	if (status & CPDMA_DESC_OWNER) {
806 		chan->stats.busy_dequeue++;
807 		status = -EBUSY;
808 		goto unlock_ret;
809 	}
810 
811 	if (status & CPDMA_DESC_PASS_CRC)
812 		outlen -= CPDMA_DESC_CRC_LEN;
813 
814 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
815 			    CPDMA_DESC_PORT_MASK);
816 
817 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
818 	chan_write(chan, cp, desc_dma);
819 	chan->count--;
820 	chan->stats.good_dequeue++;
821 
822 	if (status & CPDMA_DESC_EOQ) {
823 		chan->stats.requeue++;
824 		chan_write(chan, hdp, desc_phys(pool, chan->head));
825 	}
826 
827 	spin_unlock_irqrestore(&chan->lock, flags);
828 	if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
829 		cb_status = -ENOSYS;
830 	else
831 		cb_status = status;
832 
833 	__cpdma_chan_free(chan, desc, outlen, cb_status);
834 	return status;
835 
836 unlock_ret:
837 	spin_unlock_irqrestore(&chan->lock, flags);
838 	return status;
839 }
840 
841 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
842 {
843 	int used = 0, ret = 0;
844 
845 	if (chan->state != CPDMA_STATE_ACTIVE)
846 		return -EINVAL;
847 
848 	while (used < quota) {
849 		ret = __cpdma_chan_process(chan);
850 		if (ret < 0)
851 			break;
852 		used++;
853 	}
854 	return used;
855 }
856 EXPORT_SYMBOL_GPL(cpdma_chan_process);
857 
858 int cpdma_chan_start(struct cpdma_chan *chan)
859 {
860 	struct cpdma_ctlr	*ctlr = chan->ctlr;
861 	struct cpdma_desc_pool	*pool = ctlr->pool;
862 	unsigned long		flags;
863 
864 	spin_lock_irqsave(&chan->lock, flags);
865 	if (chan->state != CPDMA_STATE_IDLE) {
866 		spin_unlock_irqrestore(&chan->lock, flags);
867 		return -EBUSY;
868 	}
869 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
870 		spin_unlock_irqrestore(&chan->lock, flags);
871 		return -EINVAL;
872 	}
873 	dma_reg_write(ctlr, chan->int_set, chan->mask);
874 	chan->state = CPDMA_STATE_ACTIVE;
875 	if (chan->head) {
876 		chan_write(chan, hdp, desc_phys(pool, chan->head));
877 		if (chan->rxfree)
878 			chan_write(chan, rxfree, chan->count);
879 	}
880 
881 	spin_unlock_irqrestore(&chan->lock, flags);
882 	return 0;
883 }
884 EXPORT_SYMBOL_GPL(cpdma_chan_start);
885 
886 int cpdma_chan_stop(struct cpdma_chan *chan)
887 {
888 	struct cpdma_ctlr	*ctlr = chan->ctlr;
889 	struct cpdma_desc_pool	*pool = ctlr->pool;
890 	unsigned long		flags;
891 	int			ret;
892 	unsigned		timeout;
893 
894 	spin_lock_irqsave(&chan->lock, flags);
895 	if (chan->state != CPDMA_STATE_ACTIVE) {
896 		spin_unlock_irqrestore(&chan->lock, flags);
897 		return -EINVAL;
898 	}
899 
900 	chan->state = CPDMA_STATE_TEARDOWN;
901 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
902 
903 	/* trigger teardown */
904 	dma_reg_write(ctlr, chan->td, chan_linear(chan));
905 
906 	/* wait for teardown complete */
907 	timeout = 100 * 100; /* 100 ms */
908 	while (timeout) {
909 		u32 cp = chan_read(chan, cp);
910 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
911 			break;
912 		udelay(10);
913 		timeout--;
914 	}
915 	WARN_ON(!timeout);
916 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
917 
918 	/* handle completed packets */
919 	spin_unlock_irqrestore(&chan->lock, flags);
920 	do {
921 		ret = __cpdma_chan_process(chan);
922 		if (ret < 0)
923 			break;
924 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
925 	spin_lock_irqsave(&chan->lock, flags);
926 
927 	/* remaining packets haven't been tx/rx'ed, clean them up */
928 	while (chan->head) {
929 		struct cpdma_desc __iomem *desc = chan->head;
930 		dma_addr_t next_dma;
931 
932 		next_dma = desc_read(desc, hw_next);
933 		chan->head = desc_from_phys(pool, next_dma);
934 		chan->count--;
935 		chan->stats.teardown_dequeue++;
936 
937 		/* issue callback without locks held */
938 		spin_unlock_irqrestore(&chan->lock, flags);
939 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
940 		spin_lock_irqsave(&chan->lock, flags);
941 	}
942 
943 	chan->state = CPDMA_STATE_IDLE;
944 	spin_unlock_irqrestore(&chan->lock, flags);
945 	return 0;
946 }
947 EXPORT_SYMBOL_GPL(cpdma_chan_stop);
948 
949 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
950 {
951 	unsigned long flags;
952 
953 	spin_lock_irqsave(&chan->lock, flags);
954 	if (chan->state != CPDMA_STATE_ACTIVE) {
955 		spin_unlock_irqrestore(&chan->lock, flags);
956 		return -EINVAL;
957 	}
958 
959 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
960 		      chan->mask);
961 	spin_unlock_irqrestore(&chan->lock, flags);
962 
963 	return 0;
964 }
965 
966 struct cpdma_control_info {
967 	u32		reg;
968 	u32		shift, mask;
969 	int		access;
970 #define ACCESS_RO	BIT(0)
971 #define ACCESS_WO	BIT(1)
972 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
973 };
974 
975 struct cpdma_control_info controls[] = {
976 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
977 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
978 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
979 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
980 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
981 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
982 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
983 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
984 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
985 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
986 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
987 };
988 
989 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
990 {
991 	unsigned long flags;
992 	struct cpdma_control_info *info = &controls[control];
993 	int ret;
994 
995 	spin_lock_irqsave(&ctlr->lock, flags);
996 
997 	ret = -ENOTSUPP;
998 	if (!ctlr->params.has_ext_regs)
999 		goto unlock_ret;
1000 
1001 	ret = -EINVAL;
1002 	if (ctlr->state != CPDMA_STATE_ACTIVE)
1003 		goto unlock_ret;
1004 
1005 	ret = -ENOENT;
1006 	if (control < 0 || control >= ARRAY_SIZE(controls))
1007 		goto unlock_ret;
1008 
1009 	ret = -EPERM;
1010 	if ((info->access & ACCESS_RO) != ACCESS_RO)
1011 		goto unlock_ret;
1012 
1013 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
1014 
1015 unlock_ret:
1016 	spin_unlock_irqrestore(&ctlr->lock, flags);
1017 	return ret;
1018 }
1019 
1020 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
1021 {
1022 	unsigned long flags;
1023 	struct cpdma_control_info *info = &controls[control];
1024 	int ret;
1025 	u32 val;
1026 
1027 	spin_lock_irqsave(&ctlr->lock, flags);
1028 
1029 	ret = -ENOTSUPP;
1030 	if (!ctlr->params.has_ext_regs)
1031 		goto unlock_ret;
1032 
1033 	ret = -EINVAL;
1034 	if (ctlr->state != CPDMA_STATE_ACTIVE)
1035 		goto unlock_ret;
1036 
1037 	ret = -ENOENT;
1038 	if (control < 0 || control >= ARRAY_SIZE(controls))
1039 		goto unlock_ret;
1040 
1041 	ret = -EPERM;
1042 	if ((info->access & ACCESS_WO) != ACCESS_WO)
1043 		goto unlock_ret;
1044 
1045 	val  = dma_reg_read(ctlr, info->reg);
1046 	val &= ~(info->mask << info->shift);
1047 	val |= (value & info->mask) << info->shift;
1048 	dma_reg_write(ctlr, info->reg, val);
1049 	ret = 0;
1050 
1051 unlock_ret:
1052 	spin_unlock_irqrestore(&ctlr->lock, flags);
1053 	return ret;
1054 }
1055 EXPORT_SYMBOL_GPL(cpdma_control_set);
1056 
1057 MODULE_LICENSE("GPL");
1058