1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Texas Instruments CPDMA Driver
4  *
5  * Copyright (C) 2010 Texas Instruments
6  *
7  */
8 #include <linux/kernel.h>
9 #include <linux/spinlock.h>
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/err.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/io.h>
16 #include <linux/delay.h>
17 #include <linux/genalloc.h>
18 #include "davinci_cpdma.h"
19 
20 /* DMA Registers */
21 #define CPDMA_TXIDVER		0x00
22 #define CPDMA_TXCONTROL		0x04
23 #define CPDMA_TXTEARDOWN	0x08
24 #define CPDMA_RXIDVER		0x10
25 #define CPDMA_RXCONTROL		0x14
26 #define CPDMA_SOFTRESET		0x1c
27 #define CPDMA_RXTEARDOWN	0x18
28 #define CPDMA_TX_PRI0_RATE	0x30
29 #define CPDMA_TXINTSTATRAW	0x80
30 #define CPDMA_TXINTSTATMASKED	0x84
31 #define CPDMA_TXINTMASKSET	0x88
32 #define CPDMA_TXINTMASKCLEAR	0x8c
33 #define CPDMA_MACINVECTOR	0x90
34 #define CPDMA_MACEOIVECTOR	0x94
35 #define CPDMA_RXINTSTATRAW	0xa0
36 #define CPDMA_RXINTSTATMASKED	0xa4
37 #define CPDMA_RXINTMASKSET	0xa8
38 #define CPDMA_RXINTMASKCLEAR	0xac
39 #define CPDMA_DMAINTSTATRAW	0xb0
40 #define CPDMA_DMAINTSTATMASKED	0xb4
41 #define CPDMA_DMAINTMASKSET	0xb8
42 #define CPDMA_DMAINTMASKCLEAR	0xbc
43 #define CPDMA_DMAINT_HOSTERR	BIT(1)
44 
45 /* the following exist only if has_ext_regs is set */
46 #define CPDMA_DMACONTROL	0x20
47 #define CPDMA_DMASTATUS		0x24
48 #define CPDMA_RXBUFFOFS		0x28
49 #define CPDMA_EM_CONTROL	0x2c
50 
51 /* Descriptor mode bits */
52 #define CPDMA_DESC_SOP		BIT(31)
53 #define CPDMA_DESC_EOP		BIT(30)
54 #define CPDMA_DESC_OWNER	BIT(29)
55 #define CPDMA_DESC_EOQ		BIT(28)
56 #define CPDMA_DESC_TD_COMPLETE	BIT(27)
57 #define CPDMA_DESC_PASS_CRC	BIT(26)
58 #define CPDMA_DESC_TO_PORT_EN	BIT(20)
59 #define CPDMA_TO_PORT_SHIFT	16
60 #define CPDMA_DESC_PORT_MASK	(BIT(18) | BIT(17) | BIT(16))
61 #define CPDMA_DESC_CRC_LEN	4
62 
63 #define CPDMA_TEARDOWN_VALUE	0xfffffffc
64 
65 #define CPDMA_MAX_RLIM_CNT	16384
66 
67 struct cpdma_desc {
68 	/* hardware fields */
69 	u32			hw_next;
70 	u32			hw_buffer;
71 	u32			hw_len;
72 	u32			hw_mode;
73 	/* software fields */
74 	void			*sw_token;
75 	u32			sw_buffer;
76 	u32			sw_len;
77 };
78 
79 struct cpdma_desc_pool {
80 	phys_addr_t		phys;
81 	dma_addr_t		hw_addr;
82 	void __iomem		*iomap;		/* ioremap map */
83 	void			*cpumap;	/* dma_alloc map */
84 	int			desc_size, mem_size;
85 	int			num_desc;
86 	struct device		*dev;
87 	struct gen_pool		*gen_pool;
88 };
89 
90 enum cpdma_state {
91 	CPDMA_STATE_IDLE,
92 	CPDMA_STATE_ACTIVE,
93 	CPDMA_STATE_TEARDOWN,
94 };
95 
96 struct cpdma_ctlr {
97 	enum cpdma_state	state;
98 	struct cpdma_params	params;
99 	struct device		*dev;
100 	struct cpdma_desc_pool	*pool;
101 	spinlock_t		lock;
102 	struct cpdma_chan	*channels[2 * CPDMA_MAX_CHANNELS];
103 	int chan_num;
104 	int			num_rx_desc; /* RX descriptors number */
105 	int			num_tx_desc; /* TX descriptors number */
106 };
107 
108 struct cpdma_chan {
109 	struct cpdma_desc __iomem	*head, *tail;
110 	void __iomem			*hdp, *cp, *rxfree;
111 	enum cpdma_state		state;
112 	struct cpdma_ctlr		*ctlr;
113 	int				chan_num;
114 	spinlock_t			lock;
115 	int				count;
116 	u32				desc_num;
117 	u32				mask;
118 	cpdma_handler_fn		handler;
119 	enum dma_data_direction		dir;
120 	struct cpdma_chan_stats		stats;
121 	/* offsets into dmaregs */
122 	int	int_set, int_clear, td;
123 	int				weight;
124 	u32				rate_factor;
125 	u32				rate;
126 };
127 
128 struct cpdma_control_info {
129 	u32		reg;
130 	u32		shift, mask;
131 	int		access;
132 #define ACCESS_RO	BIT(0)
133 #define ACCESS_WO	BIT(1)
134 #define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
135 };
136 
137 static struct cpdma_control_info controls[] = {
138 	[CPDMA_TX_RLIM]		  = {CPDMA_DMACONTROL,	8,  0xffff, ACCESS_RW},
139 	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
140 	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
141 	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
142 	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
143 	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
144 	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
145 	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
146 	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
147 	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
148 	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
149 	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
150 };
151 
152 #define tx_chan_num(chan)	(chan)
153 #define rx_chan_num(chan)	((chan) + CPDMA_MAX_CHANNELS)
154 #define is_rx_chan(chan)	((chan)->chan_num >= CPDMA_MAX_CHANNELS)
155 #define is_tx_chan(chan)	(!is_rx_chan(chan))
156 #define __chan_linear(chan_num)	((chan_num) & (CPDMA_MAX_CHANNELS - 1))
157 #define chan_linear(chan)	__chan_linear((chan)->chan_num)
158 
159 /* The following make access to common cpdma_ctlr params more readable */
160 #define dmaregs		params.dmaregs
161 #define num_chan	params.num_chan
162 
163 /* various accessors */
164 #define dma_reg_read(ctlr, ofs)		readl((ctlr)->dmaregs + (ofs))
165 #define chan_read(chan, fld)		readl((chan)->fld)
166 #define desc_read(desc, fld)		readl(&(desc)->fld)
167 #define dma_reg_write(ctlr, ofs, v)	writel(v, (ctlr)->dmaregs + (ofs))
168 #define chan_write(chan, fld, v)	writel(v, (chan)->fld)
169 #define desc_write(desc, fld, v)	writel((u32)(v), &(desc)->fld)
170 
171 #define cpdma_desc_to_port(chan, mode, directed)			\
172 	do {								\
173 		if (!is_rx_chan(chan) && ((directed == 1) ||		\
174 					  (directed == 2)))		\
175 			mode |= (CPDMA_DESC_TO_PORT_EN |		\
176 				 (directed << CPDMA_TO_PORT_SHIFT));	\
177 	} while (0)
178 
179 static void cpdma_desc_pool_destroy(struct cpdma_ctlr *ctlr)
180 {
181 	struct cpdma_desc_pool *pool = ctlr->pool;
182 
183 	if (!pool)
184 		return;
185 
186 	WARN(gen_pool_size(pool->gen_pool) != gen_pool_avail(pool->gen_pool),
187 	     "cpdma_desc_pool size %zd != avail %zd",
188 	     gen_pool_size(pool->gen_pool),
189 	     gen_pool_avail(pool->gen_pool));
190 	if (pool->cpumap)
191 		dma_free_coherent(ctlr->dev, pool->mem_size, pool->cpumap,
192 				  pool->phys);
193 }
194 
195 /*
196  * Utility constructs for a cpdma descriptor pool.  Some devices (e.g. davinci
197  * emac) have dedicated on-chip memory for these descriptors.  Some other
198  * devices (e.g. cpsw switches) use plain old memory.  Descriptor pools
199  * abstract out these details
200  */
201 static int cpdma_desc_pool_create(struct cpdma_ctlr *ctlr)
202 {
203 	struct cpdma_params *cpdma_params = &ctlr->params;
204 	struct cpdma_desc_pool *pool;
205 	int ret = -ENOMEM;
206 
207 	pool = devm_kzalloc(ctlr->dev, sizeof(*pool), GFP_KERNEL);
208 	if (!pool)
209 		goto gen_pool_create_fail;
210 	ctlr->pool = pool;
211 
212 	pool->mem_size	= cpdma_params->desc_mem_size;
213 	pool->desc_size	= ALIGN(sizeof(struct cpdma_desc),
214 				cpdma_params->desc_align);
215 	pool->num_desc	= pool->mem_size / pool->desc_size;
216 
217 	if (cpdma_params->descs_pool_size) {
218 		/* recalculate memory size required cpdma descriptor pool
219 		 * basing on number of descriptors specified by user and
220 		 * if memory size > CPPI internal RAM size (desc_mem_size)
221 		 * then switch to use DDR
222 		 */
223 		pool->num_desc = cpdma_params->descs_pool_size;
224 		pool->mem_size = pool->desc_size * pool->num_desc;
225 		if (pool->mem_size > cpdma_params->desc_mem_size)
226 			cpdma_params->desc_mem_phys = 0;
227 	}
228 
229 	pool->gen_pool = devm_gen_pool_create(ctlr->dev, ilog2(pool->desc_size),
230 					      -1, "cpdma");
231 	if (IS_ERR(pool->gen_pool)) {
232 		ret = PTR_ERR(pool->gen_pool);
233 		dev_err(ctlr->dev, "pool create failed %d\n", ret);
234 		goto gen_pool_create_fail;
235 	}
236 
237 	if (cpdma_params->desc_mem_phys) {
238 		pool->phys  = cpdma_params->desc_mem_phys;
239 		pool->iomap = devm_ioremap(ctlr->dev, pool->phys,
240 					   pool->mem_size);
241 		pool->hw_addr = cpdma_params->desc_hw_addr;
242 	} else {
243 		pool->cpumap = dma_alloc_coherent(ctlr->dev,  pool->mem_size,
244 						  &pool->hw_addr, GFP_KERNEL);
245 		pool->iomap = (void __iomem __force *)pool->cpumap;
246 		pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
247 	}
248 
249 	if (!pool->iomap)
250 		goto gen_pool_create_fail;
251 
252 	ret = gen_pool_add_virt(pool->gen_pool, (unsigned long)pool->iomap,
253 				pool->phys, pool->mem_size, -1);
254 	if (ret < 0) {
255 		dev_err(ctlr->dev, "pool add failed %d\n", ret);
256 		goto gen_pool_add_virt_fail;
257 	}
258 
259 	return 0;
260 
261 gen_pool_add_virt_fail:
262 	cpdma_desc_pool_destroy(ctlr);
263 gen_pool_create_fail:
264 	ctlr->pool = NULL;
265 	return ret;
266 }
267 
268 static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
269 		  struct cpdma_desc __iomem *desc)
270 {
271 	if (!desc)
272 		return 0;
273 	return pool->hw_addr + (__force long)desc - (__force long)pool->iomap;
274 }
275 
276 static inline struct cpdma_desc __iomem *
277 desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
278 {
279 	return dma ? pool->iomap + dma - pool->hw_addr : NULL;
280 }
281 
282 static struct cpdma_desc __iomem *
283 cpdma_desc_alloc(struct cpdma_desc_pool *pool)
284 {
285 	return (struct cpdma_desc __iomem *)
286 		gen_pool_alloc(pool->gen_pool, pool->desc_size);
287 }
288 
289 static void cpdma_desc_free(struct cpdma_desc_pool *pool,
290 			    struct cpdma_desc __iomem *desc, int num_desc)
291 {
292 	gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size);
293 }
294 
295 static int _cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
296 {
297 	struct cpdma_control_info *info = &controls[control];
298 	u32 val;
299 
300 	if (!ctlr->params.has_ext_regs)
301 		return -ENOTSUPP;
302 
303 	if (ctlr->state != CPDMA_STATE_ACTIVE)
304 		return -EINVAL;
305 
306 	if (control < 0 || control >= ARRAY_SIZE(controls))
307 		return -ENOENT;
308 
309 	if ((info->access & ACCESS_WO) != ACCESS_WO)
310 		return -EPERM;
311 
312 	val  = dma_reg_read(ctlr, info->reg);
313 	val &= ~(info->mask << info->shift);
314 	val |= (value & info->mask) << info->shift;
315 	dma_reg_write(ctlr, info->reg, val);
316 
317 	return 0;
318 }
319 
320 static int _cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
321 {
322 	struct cpdma_control_info *info = &controls[control];
323 	int ret;
324 
325 	if (!ctlr->params.has_ext_regs)
326 		return -ENOTSUPP;
327 
328 	if (ctlr->state != CPDMA_STATE_ACTIVE)
329 		return -EINVAL;
330 
331 	if (control < 0 || control >= ARRAY_SIZE(controls))
332 		return -ENOENT;
333 
334 	if ((info->access & ACCESS_RO) != ACCESS_RO)
335 		return -EPERM;
336 
337 	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
338 	return ret;
339 }
340 
341 /* cpdma_chan_set_chan_shaper - set shaper for a channel
342  * Has to be called under ctlr lock
343  */
344 static int cpdma_chan_set_chan_shaper(struct cpdma_chan *chan)
345 {
346 	struct cpdma_ctlr *ctlr = chan->ctlr;
347 	u32 rate_reg;
348 	u32 rmask;
349 	int ret;
350 
351 	if (!chan->rate)
352 		return 0;
353 
354 	rate_reg = CPDMA_TX_PRI0_RATE + 4 * chan->chan_num;
355 	dma_reg_write(ctlr, rate_reg, chan->rate_factor);
356 
357 	rmask = _cpdma_control_get(ctlr, CPDMA_TX_RLIM);
358 	rmask |= chan->mask;
359 
360 	ret = _cpdma_control_set(ctlr, CPDMA_TX_RLIM, rmask);
361 	return ret;
362 }
363 
364 static int cpdma_chan_on(struct cpdma_chan *chan)
365 {
366 	struct cpdma_ctlr *ctlr = chan->ctlr;
367 	struct cpdma_desc_pool	*pool = ctlr->pool;
368 	unsigned long flags;
369 
370 	spin_lock_irqsave(&chan->lock, flags);
371 	if (chan->state != CPDMA_STATE_IDLE) {
372 		spin_unlock_irqrestore(&chan->lock, flags);
373 		return -EBUSY;
374 	}
375 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
376 		spin_unlock_irqrestore(&chan->lock, flags);
377 		return -EINVAL;
378 	}
379 	dma_reg_write(ctlr, chan->int_set, chan->mask);
380 	chan->state = CPDMA_STATE_ACTIVE;
381 	if (chan->head) {
382 		chan_write(chan, hdp, desc_phys(pool, chan->head));
383 		if (chan->rxfree)
384 			chan_write(chan, rxfree, chan->count);
385 	}
386 
387 	spin_unlock_irqrestore(&chan->lock, flags);
388 	return 0;
389 }
390 
391 /* cpdma_chan_fit_rate - set rate for a channel and check if it's possible.
392  * rmask - mask of rate limited channels
393  * Returns min rate in Kb/s
394  */
395 static int cpdma_chan_fit_rate(struct cpdma_chan *ch, u32 rate,
396 			       u32 *rmask, int *prio_mode)
397 {
398 	struct cpdma_ctlr *ctlr = ch->ctlr;
399 	struct cpdma_chan *chan;
400 	u32 old_rate = ch->rate;
401 	u32 new_rmask = 0;
402 	int rlim = 0;
403 	int i;
404 
405 	for (i = tx_chan_num(0); i < tx_chan_num(CPDMA_MAX_CHANNELS); i++) {
406 		chan = ctlr->channels[i];
407 		if (!chan)
408 			continue;
409 
410 		if (chan == ch)
411 			chan->rate = rate;
412 
413 		if (chan->rate) {
414 			rlim = 1;
415 			new_rmask |= chan->mask;
416 			continue;
417 		}
418 
419 		if (rlim)
420 			goto err;
421 	}
422 
423 	*rmask = new_rmask;
424 	*prio_mode = rlim;
425 	return 0;
426 
427 err:
428 	ch->rate = old_rate;
429 	dev_err(ctlr->dev, "Upper cpdma ch%d is not rate limited\n",
430 		chan->chan_num);
431 	return -EINVAL;
432 }
433 
434 static u32 cpdma_chan_set_factors(struct cpdma_ctlr *ctlr,
435 				  struct cpdma_chan *ch)
436 {
437 	u32 delta = UINT_MAX, prev_delta = UINT_MAX, best_delta = UINT_MAX;
438 	u32 best_send_cnt = 0, best_idle_cnt = 0;
439 	u32 new_rate, best_rate = 0, rate_reg;
440 	u64 send_cnt, idle_cnt;
441 	u32 min_send_cnt, freq;
442 	u64 divident, divisor;
443 
444 	if (!ch->rate) {
445 		ch->rate_factor = 0;
446 		goto set_factor;
447 	}
448 
449 	freq = ctlr->params.bus_freq_mhz * 1000 * 32;
450 	if (!freq) {
451 		dev_err(ctlr->dev, "The bus frequency is not set\n");
452 		return -EINVAL;
453 	}
454 
455 	min_send_cnt = freq - ch->rate;
456 	send_cnt = DIV_ROUND_UP(min_send_cnt, ch->rate);
457 	while (send_cnt <= CPDMA_MAX_RLIM_CNT) {
458 		divident = ch->rate * send_cnt;
459 		divisor = min_send_cnt;
460 		idle_cnt = DIV_ROUND_CLOSEST_ULL(divident, divisor);
461 
462 		divident = freq * idle_cnt;
463 		divisor = idle_cnt + send_cnt;
464 		new_rate = DIV_ROUND_CLOSEST_ULL(divident, divisor);
465 
466 		delta = new_rate >= ch->rate ? new_rate - ch->rate : delta;
467 		if (delta < best_delta) {
468 			best_delta = delta;
469 			best_send_cnt = send_cnt;
470 			best_idle_cnt = idle_cnt;
471 			best_rate = new_rate;
472 
473 			if (!delta)
474 				break;
475 		}
476 
477 		if (prev_delta >= delta) {
478 			prev_delta = delta;
479 			send_cnt++;
480 			continue;
481 		}
482 
483 		idle_cnt++;
484 		divident = freq * idle_cnt;
485 		send_cnt = DIV_ROUND_CLOSEST_ULL(divident, ch->rate);
486 		send_cnt -= idle_cnt;
487 		prev_delta = UINT_MAX;
488 	}
489 
490 	ch->rate = best_rate;
491 	ch->rate_factor = best_send_cnt | (best_idle_cnt << 16);
492 
493 set_factor:
494 	rate_reg = CPDMA_TX_PRI0_RATE + 4 * ch->chan_num;
495 	dma_reg_write(ctlr, rate_reg, ch->rate_factor);
496 	return 0;
497 }
498 
499 struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
500 {
501 	struct cpdma_ctlr *ctlr;
502 
503 	ctlr = devm_kzalloc(params->dev, sizeof(*ctlr), GFP_KERNEL);
504 	if (!ctlr)
505 		return NULL;
506 
507 	ctlr->state = CPDMA_STATE_IDLE;
508 	ctlr->params = *params;
509 	ctlr->dev = params->dev;
510 	ctlr->chan_num = 0;
511 	spin_lock_init(&ctlr->lock);
512 
513 	if (cpdma_desc_pool_create(ctlr))
514 		return NULL;
515 	/* split pool equally between RX/TX by default */
516 	ctlr->num_tx_desc = ctlr->pool->num_desc / 2;
517 	ctlr->num_rx_desc = ctlr->pool->num_desc - ctlr->num_tx_desc;
518 
519 	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
520 		ctlr->num_chan = CPDMA_MAX_CHANNELS;
521 	return ctlr;
522 }
523 
524 int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
525 {
526 	struct cpdma_chan *chan;
527 	unsigned long flags;
528 	int i, prio_mode;
529 
530 	spin_lock_irqsave(&ctlr->lock, flags);
531 	if (ctlr->state != CPDMA_STATE_IDLE) {
532 		spin_unlock_irqrestore(&ctlr->lock, flags);
533 		return -EBUSY;
534 	}
535 
536 	if (ctlr->params.has_soft_reset) {
537 		unsigned timeout = 10 * 100;
538 
539 		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
540 		while (timeout) {
541 			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
542 				break;
543 			udelay(10);
544 			timeout--;
545 		}
546 		WARN_ON(!timeout);
547 	}
548 
549 	for (i = 0; i < ctlr->num_chan; i++) {
550 		writel(0, ctlr->params.txhdp + 4 * i);
551 		writel(0, ctlr->params.rxhdp + 4 * i);
552 		writel(0, ctlr->params.txcp + 4 * i);
553 		writel(0, ctlr->params.rxcp + 4 * i);
554 	}
555 
556 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
557 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
558 
559 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
560 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
561 
562 	ctlr->state = CPDMA_STATE_ACTIVE;
563 
564 	prio_mode = 0;
565 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
566 		chan = ctlr->channels[i];
567 		if (chan) {
568 			cpdma_chan_set_chan_shaper(chan);
569 			cpdma_chan_on(chan);
570 
571 			/* off prio mode if all tx channels are rate limited */
572 			if (is_tx_chan(chan) && !chan->rate)
573 				prio_mode = 1;
574 		}
575 	}
576 
577 	_cpdma_control_set(ctlr, CPDMA_TX_PRIO_FIXED, prio_mode);
578 	_cpdma_control_set(ctlr, CPDMA_RX_BUFFER_OFFSET, 0);
579 
580 	spin_unlock_irqrestore(&ctlr->lock, flags);
581 	return 0;
582 }
583 
584 int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
585 {
586 	unsigned long flags;
587 	int i;
588 
589 	spin_lock_irqsave(&ctlr->lock, flags);
590 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
591 		spin_unlock_irqrestore(&ctlr->lock, flags);
592 		return -EINVAL;
593 	}
594 
595 	ctlr->state = CPDMA_STATE_TEARDOWN;
596 	spin_unlock_irqrestore(&ctlr->lock, flags);
597 
598 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
599 		if (ctlr->channels[i])
600 			cpdma_chan_stop(ctlr->channels[i]);
601 	}
602 
603 	spin_lock_irqsave(&ctlr->lock, flags);
604 	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
605 	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
606 
607 	dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
608 	dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
609 
610 	ctlr->state = CPDMA_STATE_IDLE;
611 
612 	spin_unlock_irqrestore(&ctlr->lock, flags);
613 	return 0;
614 }
615 
616 int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
617 {
618 	int ret = 0, i;
619 
620 	if (!ctlr)
621 		return -EINVAL;
622 
623 	if (ctlr->state != CPDMA_STATE_IDLE)
624 		cpdma_ctlr_stop(ctlr);
625 
626 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
627 		cpdma_chan_destroy(ctlr->channels[i]);
628 
629 	cpdma_desc_pool_destroy(ctlr);
630 	return ret;
631 }
632 
633 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
634 {
635 	unsigned long flags;
636 	int i;
637 
638 	spin_lock_irqsave(&ctlr->lock, flags);
639 	if (ctlr->state != CPDMA_STATE_ACTIVE) {
640 		spin_unlock_irqrestore(&ctlr->lock, flags);
641 		return -EINVAL;
642 	}
643 
644 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
645 		if (ctlr->channels[i])
646 			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
647 	}
648 
649 	spin_unlock_irqrestore(&ctlr->lock, flags);
650 	return 0;
651 }
652 
653 void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
654 {
655 	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
656 }
657 
658 u32 cpdma_ctrl_rxchs_state(struct cpdma_ctlr *ctlr)
659 {
660 	return dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED);
661 }
662 
663 u32 cpdma_ctrl_txchs_state(struct cpdma_ctlr *ctlr)
664 {
665 	return dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED);
666 }
667 
668 static void cpdma_chan_set_descs(struct cpdma_ctlr *ctlr,
669 				 int rx, int desc_num,
670 				 int per_ch_desc)
671 {
672 	struct cpdma_chan *chan, *most_chan = NULL;
673 	int desc_cnt = desc_num;
674 	int most_dnum = 0;
675 	int min, max, i;
676 
677 	if (!desc_num)
678 		return;
679 
680 	if (rx) {
681 		min = rx_chan_num(0);
682 		max = rx_chan_num(CPDMA_MAX_CHANNELS);
683 	} else {
684 		min = tx_chan_num(0);
685 		max = tx_chan_num(CPDMA_MAX_CHANNELS);
686 	}
687 
688 	for (i = min; i < max; i++) {
689 		chan = ctlr->channels[i];
690 		if (!chan)
691 			continue;
692 
693 		if (chan->weight)
694 			chan->desc_num = (chan->weight * desc_num) / 100;
695 		else
696 			chan->desc_num = per_ch_desc;
697 
698 		desc_cnt -= chan->desc_num;
699 
700 		if (most_dnum < chan->desc_num) {
701 			most_dnum = chan->desc_num;
702 			most_chan = chan;
703 		}
704 	}
705 	/* use remains */
706 	if (most_chan)
707 		most_chan->desc_num += desc_cnt;
708 }
709 
710 /**
711  * cpdma_chan_split_pool - Splits ctrl pool between all channels.
712  * Has to be called under ctlr lock
713  */
714 int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr)
715 {
716 	int tx_per_ch_desc = 0, rx_per_ch_desc = 0;
717 	int free_rx_num = 0, free_tx_num = 0;
718 	int rx_weight = 0, tx_weight = 0;
719 	int tx_desc_num, rx_desc_num;
720 	struct cpdma_chan *chan;
721 	int i;
722 
723 	if (!ctlr->chan_num)
724 		return 0;
725 
726 	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
727 		chan = ctlr->channels[i];
728 		if (!chan)
729 			continue;
730 
731 		if (is_rx_chan(chan)) {
732 			if (!chan->weight)
733 				free_rx_num++;
734 			rx_weight += chan->weight;
735 		} else {
736 			if (!chan->weight)
737 				free_tx_num++;
738 			tx_weight += chan->weight;
739 		}
740 	}
741 
742 	if (rx_weight > 100 || tx_weight > 100)
743 		return -EINVAL;
744 
745 	tx_desc_num = ctlr->num_tx_desc;
746 	rx_desc_num = ctlr->num_rx_desc;
747 
748 	if (free_tx_num) {
749 		tx_per_ch_desc = tx_desc_num - (tx_weight * tx_desc_num) / 100;
750 		tx_per_ch_desc /= free_tx_num;
751 	}
752 	if (free_rx_num) {
753 		rx_per_ch_desc = rx_desc_num - (rx_weight * rx_desc_num) / 100;
754 		rx_per_ch_desc /= free_rx_num;
755 	}
756 
757 	cpdma_chan_set_descs(ctlr, 0, tx_desc_num, tx_per_ch_desc);
758 	cpdma_chan_set_descs(ctlr, 1, rx_desc_num, rx_per_ch_desc);
759 
760 	return 0;
761 }
762 
763 
764 /* cpdma_chan_set_weight - set weight of a channel in percentage.
765  * Tx and Rx channels have separate weights. That is 100% for RX
766  * and 100% for Tx. The weight is used to split cpdma resources
767  * in correct proportion required by the channels, including number
768  * of descriptors. The channel rate is not enough to know the
769  * weight of a channel as the maximum rate of an interface is needed.
770  * If weight = 0, then channel uses rest of descriptors leaved by
771  * weighted channels.
772  */
773 int cpdma_chan_set_weight(struct cpdma_chan *ch, int weight)
774 {
775 	struct cpdma_ctlr *ctlr = ch->ctlr;
776 	unsigned long flags, ch_flags;
777 	int ret;
778 
779 	spin_lock_irqsave(&ctlr->lock, flags);
780 	spin_lock_irqsave(&ch->lock, ch_flags);
781 	if (ch->weight == weight) {
782 		spin_unlock_irqrestore(&ch->lock, ch_flags);
783 		spin_unlock_irqrestore(&ctlr->lock, flags);
784 		return 0;
785 	}
786 	ch->weight = weight;
787 	spin_unlock_irqrestore(&ch->lock, ch_flags);
788 
789 	/* re-split pool using new channel weight */
790 	ret = cpdma_chan_split_pool(ctlr);
791 	spin_unlock_irqrestore(&ctlr->lock, flags);
792 	return ret;
793 }
794 
795 /* cpdma_chan_get_min_rate - get minimum allowed rate for channel
796  * Should be called before cpdma_chan_set_rate.
797  * Returns min rate in Kb/s
798  */
799 u32 cpdma_chan_get_min_rate(struct cpdma_ctlr *ctlr)
800 {
801 	unsigned int divident, divisor;
802 
803 	divident = ctlr->params.bus_freq_mhz * 32 * 1000;
804 	divisor = 1 + CPDMA_MAX_RLIM_CNT;
805 
806 	return DIV_ROUND_UP(divident, divisor);
807 }
808 
809 /* cpdma_chan_set_rate - limits bandwidth for transmit channel.
810  * The bandwidth * limited channels have to be in order beginning from lowest.
811  * ch - transmit channel the bandwidth is configured for
812  * rate - bandwidth in Kb/s, if 0 - then off shaper
813  */
814 int cpdma_chan_set_rate(struct cpdma_chan *ch, u32 rate)
815 {
816 	unsigned long flags, ch_flags;
817 	struct cpdma_ctlr *ctlr;
818 	int ret, prio_mode;
819 	u32 rmask;
820 
821 	if (!ch || !is_tx_chan(ch))
822 		return -EINVAL;
823 
824 	if (ch->rate == rate)
825 		return rate;
826 
827 	ctlr = ch->ctlr;
828 	spin_lock_irqsave(&ctlr->lock, flags);
829 	spin_lock_irqsave(&ch->lock, ch_flags);
830 
831 	ret = cpdma_chan_fit_rate(ch, rate, &rmask, &prio_mode);
832 	if (ret)
833 		goto err;
834 
835 	ret = cpdma_chan_set_factors(ctlr, ch);
836 	if (ret)
837 		goto err;
838 
839 	spin_unlock_irqrestore(&ch->lock, ch_flags);
840 
841 	/* on shapers */
842 	_cpdma_control_set(ctlr, CPDMA_TX_RLIM, rmask);
843 	_cpdma_control_set(ctlr, CPDMA_TX_PRIO_FIXED, prio_mode);
844 	spin_unlock_irqrestore(&ctlr->lock, flags);
845 	return ret;
846 
847 err:
848 	spin_unlock_irqrestore(&ch->lock, ch_flags);
849 	spin_unlock_irqrestore(&ctlr->lock, flags);
850 	return ret;
851 }
852 
853 u32 cpdma_chan_get_rate(struct cpdma_chan *ch)
854 {
855 	unsigned long flags;
856 	u32 rate;
857 
858 	spin_lock_irqsave(&ch->lock, flags);
859 	rate = ch->rate;
860 	spin_unlock_irqrestore(&ch->lock, flags);
861 
862 	return rate;
863 }
864 
865 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
866 				     cpdma_handler_fn handler, int rx_type)
867 {
868 	int offset = chan_num * 4;
869 	struct cpdma_chan *chan;
870 	unsigned long flags;
871 
872 	chan_num = rx_type ? rx_chan_num(chan_num) : tx_chan_num(chan_num);
873 
874 	if (__chan_linear(chan_num) >= ctlr->num_chan)
875 		return ERR_PTR(-EINVAL);
876 
877 	chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
878 	if (!chan)
879 		return ERR_PTR(-ENOMEM);
880 
881 	spin_lock_irqsave(&ctlr->lock, flags);
882 	if (ctlr->channels[chan_num]) {
883 		spin_unlock_irqrestore(&ctlr->lock, flags);
884 		devm_kfree(ctlr->dev, chan);
885 		return ERR_PTR(-EBUSY);
886 	}
887 
888 	chan->ctlr	= ctlr;
889 	chan->state	= CPDMA_STATE_IDLE;
890 	chan->chan_num	= chan_num;
891 	chan->handler	= handler;
892 	chan->rate	= 0;
893 	chan->weight	= 0;
894 
895 	if (is_rx_chan(chan)) {
896 		chan->hdp	= ctlr->params.rxhdp + offset;
897 		chan->cp	= ctlr->params.rxcp + offset;
898 		chan->rxfree	= ctlr->params.rxfree + offset;
899 		chan->int_set	= CPDMA_RXINTMASKSET;
900 		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
901 		chan->td	= CPDMA_RXTEARDOWN;
902 		chan->dir	= DMA_FROM_DEVICE;
903 	} else {
904 		chan->hdp	= ctlr->params.txhdp + offset;
905 		chan->cp	= ctlr->params.txcp + offset;
906 		chan->int_set	= CPDMA_TXINTMASKSET;
907 		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
908 		chan->td	= CPDMA_TXTEARDOWN;
909 		chan->dir	= DMA_TO_DEVICE;
910 	}
911 	chan->mask = BIT(chan_linear(chan));
912 
913 	spin_lock_init(&chan->lock);
914 
915 	ctlr->channels[chan_num] = chan;
916 	ctlr->chan_num++;
917 
918 	cpdma_chan_split_pool(ctlr);
919 
920 	spin_unlock_irqrestore(&ctlr->lock, flags);
921 	return chan;
922 }
923 
924 int cpdma_chan_get_rx_buf_num(struct cpdma_chan *chan)
925 {
926 	unsigned long flags;
927 	int desc_num;
928 
929 	spin_lock_irqsave(&chan->lock, flags);
930 	desc_num = chan->desc_num;
931 	spin_unlock_irqrestore(&chan->lock, flags);
932 
933 	return desc_num;
934 }
935 
936 int cpdma_chan_destroy(struct cpdma_chan *chan)
937 {
938 	struct cpdma_ctlr *ctlr;
939 	unsigned long flags;
940 
941 	if (!chan)
942 		return -EINVAL;
943 	ctlr = chan->ctlr;
944 
945 	spin_lock_irqsave(&ctlr->lock, flags);
946 	if (chan->state != CPDMA_STATE_IDLE)
947 		cpdma_chan_stop(chan);
948 	ctlr->channels[chan->chan_num] = NULL;
949 	ctlr->chan_num--;
950 	devm_kfree(ctlr->dev, chan);
951 	cpdma_chan_split_pool(ctlr);
952 
953 	spin_unlock_irqrestore(&ctlr->lock, flags);
954 	return 0;
955 }
956 
957 int cpdma_chan_get_stats(struct cpdma_chan *chan,
958 			 struct cpdma_chan_stats *stats)
959 {
960 	unsigned long flags;
961 	if (!chan)
962 		return -EINVAL;
963 	spin_lock_irqsave(&chan->lock, flags);
964 	memcpy(stats, &chan->stats, sizeof(*stats));
965 	spin_unlock_irqrestore(&chan->lock, flags);
966 	return 0;
967 }
968 
969 static void __cpdma_chan_submit(struct cpdma_chan *chan,
970 				struct cpdma_desc __iomem *desc)
971 {
972 	struct cpdma_ctlr		*ctlr = chan->ctlr;
973 	struct cpdma_desc __iomem	*prev = chan->tail;
974 	struct cpdma_desc_pool		*pool = ctlr->pool;
975 	dma_addr_t			desc_dma;
976 	u32				mode;
977 
978 	desc_dma = desc_phys(pool, desc);
979 
980 	/* simple case - idle channel */
981 	if (!chan->head) {
982 		chan->stats.head_enqueue++;
983 		chan->head = desc;
984 		chan->tail = desc;
985 		if (chan->state == CPDMA_STATE_ACTIVE)
986 			chan_write(chan, hdp, desc_dma);
987 		return;
988 	}
989 
990 	/* first chain the descriptor at the tail of the list */
991 	desc_write(prev, hw_next, desc_dma);
992 	chan->tail = desc;
993 	chan->stats.tail_enqueue++;
994 
995 	/* next check if EOQ has been triggered already */
996 	mode = desc_read(prev, hw_mode);
997 	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
998 	    (chan->state == CPDMA_STATE_ACTIVE)) {
999 		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
1000 		chan_write(chan, hdp, desc_dma);
1001 		chan->stats.misqueued++;
1002 	}
1003 }
1004 
1005 int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
1006 		      int len, int directed)
1007 {
1008 	struct cpdma_ctlr		*ctlr = chan->ctlr;
1009 	struct cpdma_desc __iomem	*desc;
1010 	dma_addr_t			buffer;
1011 	unsigned long			flags;
1012 	u32				mode;
1013 	int				ret = 0;
1014 
1015 	spin_lock_irqsave(&chan->lock, flags);
1016 
1017 	if (chan->state == CPDMA_STATE_TEARDOWN) {
1018 		ret = -EINVAL;
1019 		goto unlock_ret;
1020 	}
1021 
1022 	if (chan->count >= chan->desc_num)	{
1023 		chan->stats.desc_alloc_fail++;
1024 		ret = -ENOMEM;
1025 		goto unlock_ret;
1026 	}
1027 
1028 	desc = cpdma_desc_alloc(ctlr->pool);
1029 	if (!desc) {
1030 		chan->stats.desc_alloc_fail++;
1031 		ret = -ENOMEM;
1032 		goto unlock_ret;
1033 	}
1034 
1035 	if (len < ctlr->params.min_packet_size) {
1036 		len = ctlr->params.min_packet_size;
1037 		chan->stats.runt_transmit_buff++;
1038 	}
1039 
1040 	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
1041 	ret = dma_mapping_error(ctlr->dev, buffer);
1042 	if (ret) {
1043 		cpdma_desc_free(ctlr->pool, desc, 1);
1044 		ret = -EINVAL;
1045 		goto unlock_ret;
1046 	}
1047 
1048 	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
1049 	cpdma_desc_to_port(chan, mode, directed);
1050 
1051 	/* Relaxed IO accessors can be used here as there is read barrier
1052 	 * at the end of write sequence.
1053 	 */
1054 	writel_relaxed(0, &desc->hw_next);
1055 	writel_relaxed(buffer, &desc->hw_buffer);
1056 	writel_relaxed(len, &desc->hw_len);
1057 	writel_relaxed(mode | len, &desc->hw_mode);
1058 	writel_relaxed((uintptr_t)token, &desc->sw_token);
1059 	writel_relaxed(buffer, &desc->sw_buffer);
1060 	writel_relaxed(len, &desc->sw_len);
1061 	desc_read(desc, sw_len);
1062 
1063 	__cpdma_chan_submit(chan, desc);
1064 
1065 	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
1066 		chan_write(chan, rxfree, 1);
1067 
1068 	chan->count++;
1069 
1070 unlock_ret:
1071 	spin_unlock_irqrestore(&chan->lock, flags);
1072 	return ret;
1073 }
1074 
1075 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
1076 {
1077 	struct cpdma_ctlr	*ctlr = chan->ctlr;
1078 	struct cpdma_desc_pool	*pool = ctlr->pool;
1079 	bool			free_tx_desc;
1080 	unsigned long		flags;
1081 
1082 	spin_lock_irqsave(&chan->lock, flags);
1083 	free_tx_desc = (chan->count < chan->desc_num) &&
1084 			 gen_pool_avail(pool->gen_pool);
1085 	spin_unlock_irqrestore(&chan->lock, flags);
1086 	return free_tx_desc;
1087 }
1088 
1089 static void __cpdma_chan_free(struct cpdma_chan *chan,
1090 			      struct cpdma_desc __iomem *desc,
1091 			      int outlen, int status)
1092 {
1093 	struct cpdma_ctlr		*ctlr = chan->ctlr;
1094 	struct cpdma_desc_pool		*pool = ctlr->pool;
1095 	dma_addr_t			buff_dma;
1096 	int				origlen;
1097 	uintptr_t			token;
1098 
1099 	token      = desc_read(desc, sw_token);
1100 	buff_dma   = desc_read(desc, sw_buffer);
1101 	origlen    = desc_read(desc, sw_len);
1102 
1103 	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
1104 	cpdma_desc_free(pool, desc, 1);
1105 	(*chan->handler)((void *)token, outlen, status);
1106 }
1107 
1108 static int __cpdma_chan_process(struct cpdma_chan *chan)
1109 {
1110 	struct cpdma_ctlr		*ctlr = chan->ctlr;
1111 	struct cpdma_desc __iomem	*desc;
1112 	int				status, outlen;
1113 	int				cb_status = 0;
1114 	struct cpdma_desc_pool		*pool = ctlr->pool;
1115 	dma_addr_t			desc_dma;
1116 	unsigned long			flags;
1117 
1118 	spin_lock_irqsave(&chan->lock, flags);
1119 
1120 	desc = chan->head;
1121 	if (!desc) {
1122 		chan->stats.empty_dequeue++;
1123 		status = -ENOENT;
1124 		goto unlock_ret;
1125 	}
1126 	desc_dma = desc_phys(pool, desc);
1127 
1128 	status	= desc_read(desc, hw_mode);
1129 	outlen	= status & 0x7ff;
1130 	if (status & CPDMA_DESC_OWNER) {
1131 		chan->stats.busy_dequeue++;
1132 		status = -EBUSY;
1133 		goto unlock_ret;
1134 	}
1135 
1136 	if (status & CPDMA_DESC_PASS_CRC)
1137 		outlen -= CPDMA_DESC_CRC_LEN;
1138 
1139 	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
1140 			    CPDMA_DESC_PORT_MASK | CPDMA_RX_VLAN_ENCAP);
1141 
1142 	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
1143 	chan_write(chan, cp, desc_dma);
1144 	chan->count--;
1145 	chan->stats.good_dequeue++;
1146 
1147 	if ((status & CPDMA_DESC_EOQ) && chan->head) {
1148 		chan->stats.requeue++;
1149 		chan_write(chan, hdp, desc_phys(pool, chan->head));
1150 	}
1151 
1152 	spin_unlock_irqrestore(&chan->lock, flags);
1153 	if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
1154 		cb_status = -ENOSYS;
1155 	else
1156 		cb_status = status;
1157 
1158 	__cpdma_chan_free(chan, desc, outlen, cb_status);
1159 	return status;
1160 
1161 unlock_ret:
1162 	spin_unlock_irqrestore(&chan->lock, flags);
1163 	return status;
1164 }
1165 
1166 int cpdma_chan_process(struct cpdma_chan *chan, int quota)
1167 {
1168 	int used = 0, ret = 0;
1169 
1170 	if (chan->state != CPDMA_STATE_ACTIVE)
1171 		return -EINVAL;
1172 
1173 	while (used < quota) {
1174 		ret = __cpdma_chan_process(chan);
1175 		if (ret < 0)
1176 			break;
1177 		used++;
1178 	}
1179 	return used;
1180 }
1181 
1182 int cpdma_chan_start(struct cpdma_chan *chan)
1183 {
1184 	struct cpdma_ctlr *ctlr = chan->ctlr;
1185 	unsigned long flags;
1186 	int ret;
1187 
1188 	spin_lock_irqsave(&ctlr->lock, flags);
1189 	ret = cpdma_chan_set_chan_shaper(chan);
1190 	spin_unlock_irqrestore(&ctlr->lock, flags);
1191 	if (ret)
1192 		return ret;
1193 
1194 	ret = cpdma_chan_on(chan);
1195 	if (ret)
1196 		return ret;
1197 
1198 	return 0;
1199 }
1200 
1201 int cpdma_chan_stop(struct cpdma_chan *chan)
1202 {
1203 	struct cpdma_ctlr	*ctlr = chan->ctlr;
1204 	struct cpdma_desc_pool	*pool = ctlr->pool;
1205 	unsigned long		flags;
1206 	int			ret;
1207 	unsigned		timeout;
1208 
1209 	spin_lock_irqsave(&chan->lock, flags);
1210 	if (chan->state == CPDMA_STATE_TEARDOWN) {
1211 		spin_unlock_irqrestore(&chan->lock, flags);
1212 		return -EINVAL;
1213 	}
1214 
1215 	chan->state = CPDMA_STATE_TEARDOWN;
1216 	dma_reg_write(ctlr, chan->int_clear, chan->mask);
1217 
1218 	/* trigger teardown */
1219 	dma_reg_write(ctlr, chan->td, chan_linear(chan));
1220 
1221 	/* wait for teardown complete */
1222 	timeout = 100 * 100; /* 100 ms */
1223 	while (timeout) {
1224 		u32 cp = chan_read(chan, cp);
1225 		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
1226 			break;
1227 		udelay(10);
1228 		timeout--;
1229 	}
1230 	WARN_ON(!timeout);
1231 	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
1232 
1233 	/* handle completed packets */
1234 	spin_unlock_irqrestore(&chan->lock, flags);
1235 	do {
1236 		ret = __cpdma_chan_process(chan);
1237 		if (ret < 0)
1238 			break;
1239 	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
1240 	spin_lock_irqsave(&chan->lock, flags);
1241 
1242 	/* remaining packets haven't been tx/rx'ed, clean them up */
1243 	while (chan->head) {
1244 		struct cpdma_desc __iomem *desc = chan->head;
1245 		dma_addr_t next_dma;
1246 
1247 		next_dma = desc_read(desc, hw_next);
1248 		chan->head = desc_from_phys(pool, next_dma);
1249 		chan->count--;
1250 		chan->stats.teardown_dequeue++;
1251 
1252 		/* issue callback without locks held */
1253 		spin_unlock_irqrestore(&chan->lock, flags);
1254 		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
1255 		spin_lock_irqsave(&chan->lock, flags);
1256 	}
1257 
1258 	chan->state = CPDMA_STATE_IDLE;
1259 	spin_unlock_irqrestore(&chan->lock, flags);
1260 	return 0;
1261 }
1262 
1263 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
1264 {
1265 	unsigned long flags;
1266 
1267 	spin_lock_irqsave(&chan->lock, flags);
1268 	if (chan->state != CPDMA_STATE_ACTIVE) {
1269 		spin_unlock_irqrestore(&chan->lock, flags);
1270 		return -EINVAL;
1271 	}
1272 
1273 	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
1274 		      chan->mask);
1275 	spin_unlock_irqrestore(&chan->lock, flags);
1276 
1277 	return 0;
1278 }
1279 
1280 int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
1281 {
1282 	unsigned long flags;
1283 	int ret;
1284 
1285 	spin_lock_irqsave(&ctlr->lock, flags);
1286 	ret = _cpdma_control_get(ctlr, control);
1287 	spin_unlock_irqrestore(&ctlr->lock, flags);
1288 
1289 	return ret;
1290 }
1291 
1292 int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
1293 {
1294 	unsigned long flags;
1295 	int ret;
1296 
1297 	spin_lock_irqsave(&ctlr->lock, flags);
1298 	ret = _cpdma_control_set(ctlr, control, value);
1299 	spin_unlock_irqrestore(&ctlr->lock, flags);
1300 
1301 	return ret;
1302 }
1303 
1304 int cpdma_get_num_rx_descs(struct cpdma_ctlr *ctlr)
1305 {
1306 	return ctlr->num_rx_desc;
1307 }
1308 
1309 int cpdma_get_num_tx_descs(struct cpdma_ctlr *ctlr)
1310 {
1311 	return ctlr->num_tx_desc;
1312 }
1313 
1314 void cpdma_set_num_rx_descs(struct cpdma_ctlr *ctlr, int num_rx_desc)
1315 {
1316 	ctlr->num_rx_desc = num_rx_desc;
1317 	ctlr->num_tx_desc = ctlr->pool->num_desc - ctlr->num_rx_desc;
1318 }
1319