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
67struct 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
79struct 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
90enum cpdma_state {
91 CPDMA_STATE_IDLE,
92 CPDMA_STATE_ACTIVE,
93 CPDMA_STATE_TEARDOWN,
94};
95
96struct 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
108struct 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
128struct 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
137struct submit_info {
138 struct cpdma_chan *chan;
139 int directed;
140 void *token;
141 void *data_virt;
142 dma_addr_t data_dma;
143 int len;
144};
145
146static struct cpdma_control_info controls[] = {
147 [CPDMA_TX_RLIM] = {CPDMA_DMACONTROL, 8, 0xffff, ACCESS_RW},
148 [CPDMA_CMD_IDLE] = {CPDMA_DMACONTROL, 3, 1, ACCESS_WO},
149 [CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL, 4, 1, ACCESS_RW},
150 [CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL, 2, 1, ACCESS_RW},
151 [CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL, 1, 1, ACCESS_RW},
152 [CPDMA_TX_PRIO_FIXED] = {CPDMA_DMACONTROL, 0, 1, ACCESS_RW},
153 [CPDMA_STAT_IDLE] = {CPDMA_DMASTATUS, 31, 1, ACCESS_RO},
154 [CPDMA_STAT_TX_ERR_CODE] = {CPDMA_DMASTATUS, 20, 0xf, ACCESS_RW},
155 [CPDMA_STAT_TX_ERR_CHAN] = {CPDMA_DMASTATUS, 16, 0x7, ACCESS_RW},
156 [CPDMA_STAT_RX_ERR_CODE] = {CPDMA_DMASTATUS, 12, 0xf, ACCESS_RW},
157 [CPDMA_STAT_RX_ERR_CHAN] = {CPDMA_DMASTATUS, 8, 0x7, ACCESS_RW},
158 [CPDMA_RX_BUFFER_OFFSET] = {CPDMA_RXBUFFOFS, 0, 0xffff, ACCESS_RW},
159};
160
161#define tx_chan_num(chan) (chan)
162#define rx_chan_num(chan) ((chan) + CPDMA_MAX_CHANNELS)
163#define is_rx_chan(chan) ((chan)->chan_num >= CPDMA_MAX_CHANNELS)
164#define is_tx_chan(chan) (!is_rx_chan(chan))
165#define __chan_linear(chan_num) ((chan_num) & (CPDMA_MAX_CHANNELS - 1))
166#define chan_linear(chan) __chan_linear((chan)->chan_num)
167
168/* The following make access to common cpdma_ctlr params more readable */
169#define dmaregs params.dmaregs
170#define num_chan params.num_chan
171
172/* various accessors */
173#define dma_reg_read(ctlr, ofs) readl((ctlr)->dmaregs + (ofs))
174#define chan_read(chan, fld) readl((chan)->fld)
175#define desc_read(desc, fld) readl(&(desc)->fld)
176#define dma_reg_write(ctlr, ofs, v) writel(v, (ctlr)->dmaregs + (ofs))
177#define chan_write(chan, fld, v) writel(v, (chan)->fld)
178#define desc_write(desc, fld, v) writel((u32)(v), &(desc)->fld)
179
180#define cpdma_desc_to_port(chan, mode, directed) \
181 do { \
182 if (!is_rx_chan(chan) && ((directed == 1) || \
183 (directed == 2))) \
184 mode |= (CPDMA_DESC_TO_PORT_EN | \
185 (directed << CPDMA_TO_PORT_SHIFT)); \
186 } while (0)
187
188#define CPDMA_DMA_EXT_MAP BIT(16)
189
190static void cpdma_desc_pool_destroy(struct cpdma_ctlr *ctlr)
191{
192 struct cpdma_desc_pool *pool = ctlr->pool;
193
194 if (!pool)
195 return;
196
197 WARN(gen_pool_size(pool->gen_pool) != gen_pool_avail(pool->gen_pool),
198 "cpdma_desc_pool size %zd != avail %zd",
199 gen_pool_size(pool->gen_pool),
200 gen_pool_avail(pool->gen_pool));
201 if (pool->cpumap)
202 dma_free_coherent(ctlr->dev, pool->mem_size, pool->cpumap,
203 pool->phys);
204}
205
206/*
207 * Utility constructs for a cpdma descriptor pool. Some devices (e.g. davinci
208 * emac) have dedicated on-chip memory for these descriptors. Some other
209 * devices (e.g. cpsw switches) use plain old memory. Descriptor pools
210 * abstract out these details
211 */
212static int cpdma_desc_pool_create(struct cpdma_ctlr *ctlr)
213{
214 struct cpdma_params *cpdma_params = &ctlr->params;
215 struct cpdma_desc_pool *pool;
216 int ret = -ENOMEM;
217
218 pool = devm_kzalloc(ctlr->dev, sizeof(*pool), GFP_KERNEL);
219 if (!pool)
220 goto gen_pool_create_fail;
221 ctlr->pool = pool;
222
223 pool->mem_size = cpdma_params->desc_mem_size;
224 pool->desc_size = ALIGN(sizeof(struct cpdma_desc),
225 cpdma_params->desc_align);
226 pool->num_desc = pool->mem_size / pool->desc_size;
227
228 if (cpdma_params->descs_pool_size) {
229 /* recalculate memory size required cpdma descriptor pool
230 * basing on number of descriptors specified by user and
231 * if memory size > CPPI internal RAM size (desc_mem_size)
232 * then switch to use DDR
233 */
234 pool->num_desc = cpdma_params->descs_pool_size;
235 pool->mem_size = pool->desc_size * pool->num_desc;
236 if (pool->mem_size > cpdma_params->desc_mem_size)
237 cpdma_params->desc_mem_phys = 0;
238 }
239
240 pool->gen_pool = devm_gen_pool_create(ctlr->dev, ilog2(pool->desc_size),
241 -1, "cpdma");
242 if (IS_ERR(pool->gen_pool)) {
243 ret = PTR_ERR(pool->gen_pool);
244 dev_err(ctlr->dev, "pool create failed %d\n", ret);
245 goto gen_pool_create_fail;
246 }
247
248 if (cpdma_params->desc_mem_phys) {
249 pool->phys = cpdma_params->desc_mem_phys;
250 pool->iomap = devm_ioremap(ctlr->dev, pool->phys,
251 pool->mem_size);
252 pool->hw_addr = cpdma_params->desc_hw_addr;
253 } else {
254 pool->cpumap = dma_alloc_coherent(ctlr->dev, pool->mem_size,
255 &pool->hw_addr, GFP_KERNEL);
256 pool->iomap = (void __iomem __force *)pool->cpumap;
257 pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
258 }
259
260 if (!pool->iomap)
261 goto gen_pool_create_fail;
262
263 ret = gen_pool_add_virt(pool->gen_pool, (unsigned long)pool->iomap,
264 pool->phys, pool->mem_size, -1);
265 if (ret < 0) {
266 dev_err(ctlr->dev, "pool add failed %d\n", ret);
267 goto gen_pool_add_virt_fail;
268 }
269
270 return 0;
271
272gen_pool_add_virt_fail:
273 cpdma_desc_pool_destroy(ctlr);
274gen_pool_create_fail:
275 ctlr->pool = NULL;
276 return ret;
277}
278
279static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
280 struct cpdma_desc __iomem *desc)
281{
282 if (!desc)
283 return 0;
284 return pool->hw_addr + (__force long)desc - (__force long)pool->iomap;
285}
286
287static inline struct cpdma_desc __iomem *
288desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
289{
290 return dma ? pool->iomap + dma - pool->hw_addr : NULL;
291}
292
293static struct cpdma_desc __iomem *
294cpdma_desc_alloc(struct cpdma_desc_pool *pool)
295{
296 return (struct cpdma_desc __iomem *)
297 gen_pool_alloc(pool->gen_pool, pool->desc_size);
298}
299
300static void cpdma_desc_free(struct cpdma_desc_pool *pool,
301 struct cpdma_desc __iomem *desc, int num_desc)
302{
303 gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size);
304}
305
306static int _cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
307{
308 struct cpdma_control_info *info = &controls[control];
309 u32 val;
310
311 if (!ctlr->params.has_ext_regs)
312 return -ENOTSUPP;
313
314 if (ctlr->state != CPDMA_STATE_ACTIVE)
315 return -EINVAL;
316
317 if (control < 0 || control >= ARRAY_SIZE(controls))
318 return -ENOENT;
319
320 if ((info->access & ACCESS_WO) != ACCESS_WO)
321 return -EPERM;
322
323 val = dma_reg_read(ctlr, info->reg);
324 val &= ~(info->mask << info->shift);
325 val |= (value & info->mask) << info->shift;
326 dma_reg_write(ctlr, info->reg, val);
327
328 return 0;
329}
330
331static int _cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
332{
333 struct cpdma_control_info *info = &controls[control];
334 int ret;
335
336 if (!ctlr->params.has_ext_regs)
337 return -ENOTSUPP;
338
339 if (ctlr->state != CPDMA_STATE_ACTIVE)
340 return -EINVAL;
341
342 if (control < 0 || control >= ARRAY_SIZE(controls))
343 return -ENOENT;
344
345 if ((info->access & ACCESS_RO) != ACCESS_RO)
346 return -EPERM;
347
348 ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
349 return ret;
350}
351
352/* cpdma_chan_set_chan_shaper - set shaper for a channel
353 * Has to be called under ctlr lock
354 */
355static int cpdma_chan_set_chan_shaper(struct cpdma_chan *chan)
356{
357 struct cpdma_ctlr *ctlr = chan->ctlr;
358 u32 rate_reg;
359 u32 rmask;
360 int ret;
361
362 if (!chan->rate)
363 return 0;
364
365 rate_reg = CPDMA_TX_PRI0_RATE + 4 * chan->chan_num;
366 dma_reg_write(ctlr, rate_reg, chan->rate_factor);
367
368 rmask = _cpdma_control_get(ctlr, CPDMA_TX_RLIM);
369 rmask |= chan->mask;
370
371 ret = _cpdma_control_set(ctlr, CPDMA_TX_RLIM, rmask);
372 return ret;
373}
374
375static int cpdma_chan_on(struct cpdma_chan *chan)
376{
377 struct cpdma_ctlr *ctlr = chan->ctlr;
378 struct cpdma_desc_pool *pool = ctlr->pool;
379 unsigned long flags;
380
381 spin_lock_irqsave(&chan->lock, flags);
382 if (chan->state != CPDMA_STATE_IDLE) {
383 spin_unlock_irqrestore(&chan->lock, flags);
384 return -EBUSY;
385 }
386 if (ctlr->state != CPDMA_STATE_ACTIVE) {
387 spin_unlock_irqrestore(&chan->lock, flags);
388 return -EINVAL;
389 }
390 dma_reg_write(ctlr, chan->int_set, chan->mask);
391 chan->state = CPDMA_STATE_ACTIVE;
392 if (chan->head) {
393 chan_write(chan, hdp, desc_phys(pool, chan->head));
394 if (chan->rxfree)
395 chan_write(chan, rxfree, chan->count);
396 }
397
398 spin_unlock_irqrestore(&chan->lock, flags);
399 return 0;
400}
401
402/* cpdma_chan_fit_rate - set rate for a channel and check if it's possible.
403 * rmask - mask of rate limited channels
404 * Returns min rate in Kb/s
405 */
406static int cpdma_chan_fit_rate(struct cpdma_chan *ch, u32 rate,
407 u32 *rmask, int *prio_mode)
408{
409 struct cpdma_ctlr *ctlr = ch->ctlr;
410 struct cpdma_chan *chan;
411 u32 old_rate = ch->rate;
412 u32 new_rmask = 0;
413 int rlim = 0;
414 int i;
415
416 for (i = tx_chan_num(0); i < tx_chan_num(CPDMA_MAX_CHANNELS); i++) {
417 chan = ctlr->channels[i];
418 if (!chan)
419 continue;
420
421 if (chan == ch)
422 chan->rate = rate;
423
424 if (chan->rate) {
425 rlim = 1;
426 new_rmask |= chan->mask;
427 continue;
428 }
429
430 if (rlim)
431 goto err;
432 }
433
434 *rmask = new_rmask;
435 *prio_mode = rlim;
436 return 0;
437
438err:
439 ch->rate = old_rate;
440 dev_err(ctlr->dev, "Upper cpdma ch%d is not rate limited\n",
441 chan->chan_num);
442 return -EINVAL;
443}
444
445static u32 cpdma_chan_set_factors(struct cpdma_ctlr *ctlr,
446 struct cpdma_chan *ch)
447{
448 u32 delta = UINT_MAX, prev_delta = UINT_MAX, best_delta = UINT_MAX;
449 u32 best_send_cnt = 0, best_idle_cnt = 0;
450 u32 new_rate, best_rate = 0, rate_reg;
451 u64 send_cnt, idle_cnt;
452 u32 min_send_cnt, freq;
453 u64 divident, divisor;
454
455 if (!ch->rate) {
456 ch->rate_factor = 0;
457 goto set_factor;
458 }
459
460 freq = ctlr->params.bus_freq_mhz * 1000 * 32;
461 if (!freq) {
462 dev_err(ctlr->dev, "The bus frequency is not set\n");
463 return -EINVAL;
464 }
465
466 min_send_cnt = freq - ch->rate;
467 send_cnt = DIV_ROUND_UP(min_send_cnt, ch->rate);
468 while (send_cnt <= CPDMA_MAX_RLIM_CNT) {
469 divident = ch->rate * send_cnt;
470 divisor = min_send_cnt;
471 idle_cnt = DIV_ROUND_CLOSEST_ULL(divident, divisor);
472
473 divident = freq * idle_cnt;
474 divisor = idle_cnt + send_cnt;
475 new_rate = DIV_ROUND_CLOSEST_ULL(divident, divisor);
476
477 delta = new_rate >= ch->rate ? new_rate - ch->rate : delta;
478 if (delta < best_delta) {
479 best_delta = delta;
480 best_send_cnt = send_cnt;
481 best_idle_cnt = idle_cnt;
482 best_rate = new_rate;
483
484 if (!delta)
485 break;
486 }
487
488 if (prev_delta >= delta) {
489 prev_delta = delta;
490 send_cnt++;
491 continue;
492 }
493
494 idle_cnt++;
495 divident = freq * idle_cnt;
496 send_cnt = DIV_ROUND_CLOSEST_ULL(divident, ch->rate);
497 send_cnt -= idle_cnt;
498 prev_delta = UINT_MAX;
499 }
500
501 ch->rate = best_rate;
502 ch->rate_factor = best_send_cnt | (best_idle_cnt << 16);
503
504set_factor:
505 rate_reg = CPDMA_TX_PRI0_RATE + 4 * ch->chan_num;
506 dma_reg_write(ctlr, rate_reg, ch->rate_factor);
507 return 0;
508}
509
510struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
511{
512 struct cpdma_ctlr *ctlr;
513
514 ctlr = devm_kzalloc(params->dev, sizeof(*ctlr), GFP_KERNEL);
515 if (!ctlr)
516 return NULL;
517
518 ctlr->state = CPDMA_STATE_IDLE;
519 ctlr->params = *params;
520 ctlr->dev = params->dev;
521 ctlr->chan_num = 0;
522 spin_lock_init(&ctlr->lock);
523
524 if (cpdma_desc_pool_create(ctlr))
525 return NULL;
526 /* split pool equally between RX/TX by default */
527 ctlr->num_tx_desc = ctlr->pool->num_desc / 2;
528 ctlr->num_rx_desc = ctlr->pool->num_desc - ctlr->num_tx_desc;
529
530 if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
531 ctlr->num_chan = CPDMA_MAX_CHANNELS;
532 return ctlr;
533}
534
535int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
536{
537 struct cpdma_chan *chan;
538 unsigned long flags;
539 int i, prio_mode;
540
541 spin_lock_irqsave(&ctlr->lock, flags);
542 if (ctlr->state != CPDMA_STATE_IDLE) {
543 spin_unlock_irqrestore(&ctlr->lock, flags);
544 return -EBUSY;
545 }
546
547 if (ctlr->params.has_soft_reset) {
548 unsigned timeout = 10 * 100;
549
550 dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
551 while (timeout) {
552 if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
553 break;
554 udelay(10);
555 timeout--;
556 }
557 WARN_ON(!timeout);
558 }
559
560 for (i = 0; i < ctlr->num_chan; i++) {
561 writel(0, ctlr->params.txhdp + 4 * i);
562 writel(0, ctlr->params.rxhdp + 4 * i);
563 writel(0, ctlr->params.txcp + 4 * i);
564 writel(0, ctlr->params.rxcp + 4 * i);
565 }
566
567 dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
568 dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
569
570 dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
571 dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
572
573 ctlr->state = CPDMA_STATE_ACTIVE;
574
575 prio_mode = 0;
576 for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
577 chan = ctlr->channels[i];
578 if (chan) {
579 cpdma_chan_set_chan_shaper(chan);
580 cpdma_chan_on(chan);
581
582 /* off prio mode if all tx channels are rate limited */
583 if (is_tx_chan(chan) && !chan->rate)
584 prio_mode = 1;
585 }
586 }
587
588 _cpdma_control_set(ctlr, CPDMA_TX_PRIO_FIXED, prio_mode);
589 _cpdma_control_set(ctlr, CPDMA_RX_BUFFER_OFFSET, 0);
590
591 spin_unlock_irqrestore(&ctlr->lock, flags);
592 return 0;
593}
594
595int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
596{
597 unsigned long flags;
598 int i;
599
600 spin_lock_irqsave(&ctlr->lock, flags);
601 if (ctlr->state != CPDMA_STATE_ACTIVE) {
602 spin_unlock_irqrestore(&ctlr->lock, flags);
603 return -EINVAL;
604 }
605
606 ctlr->state = CPDMA_STATE_TEARDOWN;
607 spin_unlock_irqrestore(&ctlr->lock, flags);
608
609 for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
610 if (ctlr->channels[i])
611 cpdma_chan_stop(ctlr->channels[i]);
612 }
613
614 spin_lock_irqsave(&ctlr->lock, flags);
615 dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
616 dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
617
618 dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
619 dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
620
621 ctlr->state = CPDMA_STATE_IDLE;
622
623 spin_unlock_irqrestore(&ctlr->lock, flags);
624 return 0;
625}
626
627int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
628{
629 int ret = 0, i;
630
631 if (!ctlr)
632 return -EINVAL;
633
634 if (ctlr->state != CPDMA_STATE_IDLE)
635 cpdma_ctlr_stop(ctlr);
636
637 for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
638 cpdma_chan_destroy(ctlr->channels[i]);
639
640 cpdma_desc_pool_destroy(ctlr);
641 return ret;
642}
643
644int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
645{
646 unsigned long flags;
647 int i;
648
649 spin_lock_irqsave(&ctlr->lock, flags);
650 if (ctlr->state != CPDMA_STATE_ACTIVE) {
651 spin_unlock_irqrestore(&ctlr->lock, flags);
652 return -EINVAL;
653 }
654
655 for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
656 if (ctlr->channels[i])
657 cpdma_chan_int_ctrl(ctlr->channels[i], enable);
658 }
659
660 spin_unlock_irqrestore(&ctlr->lock, flags);
661 return 0;
662}
663
664void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
665{
666 dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
667}
668
669u32 cpdma_ctrl_rxchs_state(struct cpdma_ctlr *ctlr)
670{
671 return dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED);
672}
673
674u32 cpdma_ctrl_txchs_state(struct cpdma_ctlr *ctlr)
675{
676 return dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED);
677}
678
679static void cpdma_chan_set_descs(struct cpdma_ctlr *ctlr,
680 int rx, int desc_num,
681 int per_ch_desc)
682{
683 struct cpdma_chan *chan, *most_chan = NULL;
684 int desc_cnt = desc_num;
685 int most_dnum = 0;
686 int min, max, i;
687
688 if (!desc_num)
689 return;
690
691 if (rx) {
692 min = rx_chan_num(0);
693 max = rx_chan_num(CPDMA_MAX_CHANNELS);
694 } else {
695 min = tx_chan_num(0);
696 max = tx_chan_num(CPDMA_MAX_CHANNELS);
697 }
698
699 for (i = min; i < max; i++) {
700 chan = ctlr->channels[i];
701 if (!chan)
702 continue;
703
704 if (chan->weight)
705 chan->desc_num = (chan->weight * desc_num) / 100;
706 else
707 chan->desc_num = per_ch_desc;
708
709 desc_cnt -= chan->desc_num;
710
711 if (most_dnum < chan->desc_num) {
712 most_dnum = chan->desc_num;
713 most_chan = chan;
714 }
715 }
716 /* use remains */
717 if (most_chan)
718 most_chan->desc_num += desc_cnt;
719}
720
721/*
722 * cpdma_chan_split_pool - Splits ctrl pool between all channels.
723 * Has to be called under ctlr lock
724 */
725static int cpdma_chan_split_pool(struct cpdma_ctlr *ctlr)
726{
727 int tx_per_ch_desc = 0, rx_per_ch_desc = 0;
728 int free_rx_num = 0, free_tx_num = 0;
729 int rx_weight = 0, tx_weight = 0;
730 int tx_desc_num, rx_desc_num;
731 struct cpdma_chan *chan;
732 int i;
733
734 if (!ctlr->chan_num)
735 return 0;
736
737 for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
738 chan = ctlr->channels[i];
739 if (!chan)
740 continue;
741
742 if (is_rx_chan(chan)) {
743 if (!chan->weight)
744 free_rx_num++;
745 rx_weight += chan->weight;
746 } else {
747 if (!chan->weight)
748 free_tx_num++;
749 tx_weight += chan->weight;
750 }
751 }
752
753 if (rx_weight > 100 || tx_weight > 100)
754 return -EINVAL;
755
756 tx_desc_num = ctlr->num_tx_desc;
757 rx_desc_num = ctlr->num_rx_desc;
758
759 if (free_tx_num) {
760 tx_per_ch_desc = tx_desc_num - (tx_weight * tx_desc_num) / 100;
761 tx_per_ch_desc /= free_tx_num;
762 }
763 if (free_rx_num) {
764 rx_per_ch_desc = rx_desc_num - (rx_weight * rx_desc_num) / 100;
765 rx_per_ch_desc /= free_rx_num;
766 }
767
768 cpdma_chan_set_descs(ctlr, 0, tx_desc_num, tx_per_ch_desc);
769 cpdma_chan_set_descs(ctlr, 1, rx_desc_num, rx_per_ch_desc);
770
771 return 0;
772}
773
774
775/* cpdma_chan_set_weight - set weight of a channel in percentage.
776 * Tx and Rx channels have separate weights. That is 100% for RX
777 * and 100% for Tx. The weight is used to split cpdma resources
778 * in correct proportion required by the channels, including number
779 * of descriptors. The channel rate is not enough to know the
780 * weight of a channel as the maximum rate of an interface is needed.
781 * If weight = 0, then channel uses rest of descriptors leaved by
782 * weighted channels.
783 */
784int cpdma_chan_set_weight(struct cpdma_chan *ch, int weight)
785{
786 struct cpdma_ctlr *ctlr = ch->ctlr;
787 unsigned long flags, ch_flags;
788 int ret;
789
790 spin_lock_irqsave(&ctlr->lock, flags);
791 spin_lock_irqsave(&ch->lock, ch_flags);
792 if (ch->weight == weight) {
793 spin_unlock_irqrestore(&ch->lock, ch_flags);
794 spin_unlock_irqrestore(&ctlr->lock, flags);
795 return 0;
796 }
797 ch->weight = weight;
798 spin_unlock_irqrestore(&ch->lock, ch_flags);
799
800 /* re-split pool using new channel weight */
801 ret = cpdma_chan_split_pool(ctlr);
802 spin_unlock_irqrestore(&ctlr->lock, flags);
803 return ret;
804}
805
806/* cpdma_chan_get_min_rate - get minimum allowed rate for channel
807 * Should be called before cpdma_chan_set_rate.
808 * Returns min rate in Kb/s
809 */
810u32 cpdma_chan_get_min_rate(struct cpdma_ctlr *ctlr)
811{
812 unsigned int divident, divisor;
813
814 divident = ctlr->params.bus_freq_mhz * 32 * 1000;
815 divisor = 1 + CPDMA_MAX_RLIM_CNT;
816
817 return DIV_ROUND_UP(divident, divisor);
818}
819
820/* cpdma_chan_set_rate - limits bandwidth for transmit channel.
821 * The bandwidth * limited channels have to be in order beginning from lowest.
822 * ch - transmit channel the bandwidth is configured for
823 * rate - bandwidth in Kb/s, if 0 - then off shaper
824 */
825int cpdma_chan_set_rate(struct cpdma_chan *ch, u32 rate)
826{
827 unsigned long flags, ch_flags;
828 struct cpdma_ctlr *ctlr;
829 int ret, prio_mode;
830 u32 rmask;
831
832 if (!ch || !is_tx_chan(ch))
833 return -EINVAL;
834
835 if (ch->rate == rate)
836 return rate;
837
838 ctlr = ch->ctlr;
839 spin_lock_irqsave(&ctlr->lock, flags);
840 spin_lock_irqsave(&ch->lock, ch_flags);
841
842 ret = cpdma_chan_fit_rate(ch, rate, &rmask, &prio_mode);
843 if (ret)
844 goto err;
845
846 ret = cpdma_chan_set_factors(ctlr, ch);
847 if (ret)
848 goto err;
849
850 spin_unlock_irqrestore(&ch->lock, ch_flags);
851
852 /* on shapers */
853 _cpdma_control_set(ctlr, CPDMA_TX_RLIM, rmask);
854 _cpdma_control_set(ctlr, CPDMA_TX_PRIO_FIXED, prio_mode);
855 spin_unlock_irqrestore(&ctlr->lock, flags);
856 return ret;
857
858err:
859 spin_unlock_irqrestore(&ch->lock, ch_flags);
860 spin_unlock_irqrestore(&ctlr->lock, flags);
861 return ret;
862}
863
864u32 cpdma_chan_get_rate(struct cpdma_chan *ch)
865{
866 unsigned long flags;
867 u32 rate;
868
869 spin_lock_irqsave(&ch->lock, flags);
870 rate = ch->rate;
871 spin_unlock_irqrestore(&ch->lock, flags);
872
873 return rate;
874}
875
876struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
877 cpdma_handler_fn handler, int rx_type)
878{
879 int offset = chan_num * 4;
880 struct cpdma_chan *chan;
881 unsigned long flags;
882
883 chan_num = rx_type ? rx_chan_num(chan_num) : tx_chan_num(chan_num);
884
885 if (__chan_linear(chan_num) >= ctlr->num_chan)
886 return ERR_PTR(-EINVAL);
887
888 chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
889 if (!chan)
890 return ERR_PTR(-ENOMEM);
891
892 spin_lock_irqsave(&ctlr->lock, flags);
893 if (ctlr->channels[chan_num]) {
894 spin_unlock_irqrestore(&ctlr->lock, flags);
895 devm_kfree(ctlr->dev, chan);
896 return ERR_PTR(-EBUSY);
897 }
898
899 chan->ctlr = ctlr;
900 chan->state = CPDMA_STATE_IDLE;
901 chan->chan_num = chan_num;
902 chan->handler = handler;
903 chan->rate = 0;
904 chan->weight = 0;
905
906 if (is_rx_chan(chan)) {
907 chan->hdp = ctlr->params.rxhdp + offset;
908 chan->cp = ctlr->params.rxcp + offset;
909 chan->rxfree = ctlr->params.rxfree + offset;
910 chan->int_set = CPDMA_RXINTMASKSET;
911 chan->int_clear = CPDMA_RXINTMASKCLEAR;
912 chan->td = CPDMA_RXTEARDOWN;
913 chan->dir = DMA_FROM_DEVICE;
914 } else {
915 chan->hdp = ctlr->params.txhdp + offset;
916 chan->cp = ctlr->params.txcp + offset;
917 chan->int_set = CPDMA_TXINTMASKSET;
918 chan->int_clear = CPDMA_TXINTMASKCLEAR;
919 chan->td = CPDMA_TXTEARDOWN;
920 chan->dir = DMA_TO_DEVICE;
921 }
922 chan->mask = BIT(chan_linear(chan));
923
924 spin_lock_init(&chan->lock);
925
926 ctlr->channels[chan_num] = chan;
927 ctlr->chan_num++;
928
929 cpdma_chan_split_pool(ctlr);
930
931 spin_unlock_irqrestore(&ctlr->lock, flags);
932 return chan;
933}
934
935int cpdma_chan_get_rx_buf_num(struct cpdma_chan *chan)
936{
937 unsigned long flags;
938 int desc_num;
939
940 spin_lock_irqsave(&chan->lock, flags);
941 desc_num = chan->desc_num;
942 spin_unlock_irqrestore(&chan->lock, flags);
943
944 return desc_num;
945}
946
947int cpdma_chan_destroy(struct cpdma_chan *chan)
948{
949 struct cpdma_ctlr *ctlr;
950 unsigned long flags;
951
952 if (!chan)
953 return -EINVAL;
954 ctlr = chan->ctlr;
955
956 spin_lock_irqsave(&ctlr->lock, flags);
957 if (chan->state != CPDMA_STATE_IDLE)
958 cpdma_chan_stop(chan);
959 ctlr->channels[chan->chan_num] = NULL;
960 ctlr->chan_num--;
961 devm_kfree(ctlr->dev, chan);
962 cpdma_chan_split_pool(ctlr);
963
964 spin_unlock_irqrestore(&ctlr->lock, flags);
965 return 0;
966}
967
968int cpdma_chan_get_stats(struct cpdma_chan *chan,
969 struct cpdma_chan_stats *stats)
970{
971 unsigned long flags;
972 if (!chan)
973 return -EINVAL;
974 spin_lock_irqsave(&chan->lock, flags);
975 memcpy(stats, &chan->stats, sizeof(*stats));
976 spin_unlock_irqrestore(&chan->lock, flags);
977 return 0;
978}
979
980static void __cpdma_chan_submit(struct cpdma_chan *chan,
981 struct cpdma_desc __iomem *desc)
982{
983 struct cpdma_ctlr *ctlr = chan->ctlr;
984 struct cpdma_desc __iomem *prev = chan->tail;
985 struct cpdma_desc_pool *pool = ctlr->pool;
986 dma_addr_t desc_dma;
987 u32 mode;
988
989 desc_dma = desc_phys(pool, desc);
990
991 /* simple case - idle channel */
992 if (!chan->head) {
993 chan->stats.head_enqueue++;
994 chan->head = desc;
995 chan->tail = desc;
996 if (chan->state == CPDMA_STATE_ACTIVE)
997 chan_write(chan, hdp, desc_dma);
998 return;
999 }
1000
1001 /* first chain the descriptor at the tail of the list */
1002 desc_write(prev, hw_next, desc_dma);
1003 chan->tail = desc;
1004 chan->stats.tail_enqueue++;
1005
1006 /* next check if EOQ has been triggered already */
1007 mode = desc_read(prev, hw_mode);
1008 if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
1009 (chan->state == CPDMA_STATE_ACTIVE)) {
1010 desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
1011 chan_write(chan, hdp, desc_dma);
1012 chan->stats.misqueued++;
1013 }
1014}
1015
1016static int cpdma_chan_submit_si(struct submit_info *si)
1017{
1018 struct cpdma_chan *chan = si->chan;
1019 struct cpdma_ctlr *ctlr = chan->ctlr;
1020 int len = si->len;
1021 struct cpdma_desc __iomem *desc;
1022 dma_addr_t buffer;
1023 u32 mode;
1024 int ret;
1025
1026 if (chan->count >= chan->desc_num) {
1027 chan->stats.desc_alloc_fail++;
1028 return -ENOMEM;
1029 }
1030
1031 desc = cpdma_desc_alloc(ctlr->pool);
1032 if (!desc) {
1033 chan->stats.desc_alloc_fail++;
1034 return -ENOMEM;
1035 }
1036
1037 if (len < ctlr->params.min_packet_size) {
1038 len = ctlr->params.min_packet_size;
1039 chan->stats.runt_transmit_buff++;
1040 }
1041
1042 mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
1043 cpdma_desc_to_port(chan, mode, si->directed);
1044
1045 if (si->data_dma) {
1046 buffer = si->data_dma;
1047 dma_sync_single_for_device(ctlr->dev, buffer, len, chan->dir);
1048 } else {
1049 buffer = dma_map_single(ctlr->dev, si->data_virt, len, chan->dir);
1050 ret = dma_mapping_error(ctlr->dev, buffer);
1051 if (ret) {
1052 cpdma_desc_free(ctlr->pool, desc, 1);
1053 return -EINVAL;
1054 }
1055 }
1056
1057 /* Relaxed IO accessors can be used here as there is read barrier
1058 * at the end of write sequence.
1059 */
1060 writel_relaxed(0, &desc->hw_next);
1061 writel_relaxed(buffer, &desc->hw_buffer);
1062 writel_relaxed(len, &desc->hw_len);
1063 writel_relaxed(mode | len, &desc->hw_mode);
1064 writel_relaxed((uintptr_t)si->token, &desc->sw_token);
1065 writel_relaxed(buffer, &desc->sw_buffer);
1066 writel_relaxed(si->data_dma ? len | CPDMA_DMA_EXT_MAP : len,
1067 &desc->sw_len);
1068 desc_read(desc, sw_len);
1069
1070 __cpdma_chan_submit(chan, desc);
1071
1072 if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
1073 chan_write(chan, rxfree, 1);
1074
1075 chan->count++;
1076 return 0;
1077}
1078
1079int cpdma_chan_idle_submit(struct cpdma_chan *chan, void *token, void *data,
1080 int len, int directed)
1081{
1082 struct submit_info si;
1083 unsigned long flags;
1084 int ret;
1085
1086 si.chan = chan;
1087 si.token = token;
1088 si.data_virt = data;
1089 si.data_dma = 0;
1090 si.len = len;
1091 si.directed = directed;
1092
1093 spin_lock_irqsave(&chan->lock, flags);
1094 if (chan->state == CPDMA_STATE_TEARDOWN) {
1095 spin_unlock_irqrestore(&chan->lock, flags);
1096 return -EINVAL;
1097 }
1098
1099 ret = cpdma_chan_submit_si(&si);
1100 spin_unlock_irqrestore(&chan->lock, flags);
1101 return ret;
1102}
1103
1104int cpdma_chan_idle_submit_mapped(struct cpdma_chan *chan, void *token,
1105 dma_addr_t data, int len, int directed)
1106{
1107 struct submit_info si;
1108 unsigned long flags;
1109 int ret;
1110
1111 si.chan = chan;
1112 si.token = token;
1113 si.data_virt = NULL;
1114 si.data_dma = data;
1115 si.len = len;
1116 si.directed = directed;
1117
1118 spin_lock_irqsave(&chan->lock, flags);
1119 if (chan->state == CPDMA_STATE_TEARDOWN) {
1120 spin_unlock_irqrestore(&chan->lock, flags);
1121 return -EINVAL;
1122 }
1123
1124 ret = cpdma_chan_submit_si(&si);
1125 spin_unlock_irqrestore(&chan->lock, flags);
1126 return ret;
1127}
1128
1129int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
1130 int len, int directed)
1131{
1132 struct submit_info si;
1133 unsigned long flags;
1134 int ret;
1135
1136 si.chan = chan;
1137 si.token = token;
1138 si.data_virt = data;
1139 si.data_dma = 0;
1140 si.len = len;
1141 si.directed = directed;
1142
1143 spin_lock_irqsave(&chan->lock, flags);
1144 if (chan->state != CPDMA_STATE_ACTIVE) {
1145 spin_unlock_irqrestore(&chan->lock, flags);
1146 return -EINVAL;
1147 }
1148
1149 ret = cpdma_chan_submit_si(&si);
1150 spin_unlock_irqrestore(&chan->lock, flags);
1151 return ret;
1152}
1153
1154int cpdma_chan_submit_mapped(struct cpdma_chan *chan, void *token,
1155 dma_addr_t data, int len, int directed)
1156{
1157 struct submit_info si;
1158 unsigned long flags;
1159 int ret;
1160
1161 si.chan = chan;
1162 si.token = token;
1163 si.data_virt = NULL;
1164 si.data_dma = data;
1165 si.len = len;
1166 si.directed = directed;
1167
1168 spin_lock_irqsave(&chan->lock, flags);
1169 if (chan->state != CPDMA_STATE_ACTIVE) {
1170 spin_unlock_irqrestore(&chan->lock, flags);
1171 return -EINVAL;
1172 }
1173
1174 ret = cpdma_chan_submit_si(&si);
1175 spin_unlock_irqrestore(&chan->lock, flags);
1176 return ret;
1177}
1178
1179bool cpdma_check_free_tx_desc(struct cpdma_chan *chan)
1180{
1181 struct cpdma_ctlr *ctlr = chan->ctlr;
1182 struct cpdma_desc_pool *pool = ctlr->pool;
1183 bool free_tx_desc;
1184 unsigned long flags;
1185
1186 spin_lock_irqsave(&chan->lock, flags);
1187 free_tx_desc = (chan->count < chan->desc_num) &&
1188 gen_pool_avail(pool->gen_pool);
1189 spin_unlock_irqrestore(&chan->lock, flags);
1190 return free_tx_desc;
1191}
1192
1193static void __cpdma_chan_free(struct cpdma_chan *chan,
1194 struct cpdma_desc __iomem *desc,
1195 int outlen, int status)
1196{
1197 struct cpdma_ctlr *ctlr = chan->ctlr;
1198 struct cpdma_desc_pool *pool = ctlr->pool;
1199 dma_addr_t buff_dma;
1200 int origlen;
1201 uintptr_t token;
1202
1203 token = desc_read(desc, sw_token);
1204 origlen = desc_read(desc, sw_len);
1205
1206 buff_dma = desc_read(desc, sw_buffer);
1207 if (origlen & CPDMA_DMA_EXT_MAP) {
1208 origlen &= ~CPDMA_DMA_EXT_MAP;
1209 dma_sync_single_for_cpu(ctlr->dev, buff_dma, origlen,
1210 chan->dir);
1211 } else {
1212 dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
1213 }
1214
1215 cpdma_desc_free(pool, desc, 1);
1216 (*chan->handler)((void *)token, outlen, status);
1217}
1218
1219static int __cpdma_chan_process(struct cpdma_chan *chan)
1220{
1221 struct cpdma_ctlr *ctlr = chan->ctlr;
1222 struct cpdma_desc __iomem *desc;
1223 int status, outlen;
1224 int cb_status = 0;
1225 struct cpdma_desc_pool *pool = ctlr->pool;
1226 dma_addr_t desc_dma;
1227 unsigned long flags;
1228
1229 spin_lock_irqsave(&chan->lock, flags);
1230
1231 desc = chan->head;
1232 if (!desc) {
1233 chan->stats.empty_dequeue++;
1234 status = -ENOENT;
1235 goto unlock_ret;
1236 }
1237 desc_dma = desc_phys(pool, desc);
1238
1239 status = desc_read(desc, hw_mode);
1240 outlen = status & 0x7ff;
1241 if (status & CPDMA_DESC_OWNER) {
1242 chan->stats.busy_dequeue++;
1243 status = -EBUSY;
1244 goto unlock_ret;
1245 }
1246
1247 if (status & CPDMA_DESC_PASS_CRC)
1248 outlen -= CPDMA_DESC_CRC_LEN;
1249
1250 status = status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
1251 CPDMA_DESC_PORT_MASK | CPDMA_RX_VLAN_ENCAP);
1252
1253 chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
1254 chan_write(chan, cp, desc_dma);
1255 chan->count--;
1256 chan->stats.good_dequeue++;
1257
1258 if ((status & CPDMA_DESC_EOQ) && chan->head) {
1259 chan->stats.requeue++;
1260 chan_write(chan, hdp, desc_phys(pool, chan->head));
1261 }
1262
1263 spin_unlock_irqrestore(&chan->lock, flags);
1264 if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
1265 cb_status = -ENOSYS;
1266 else
1267 cb_status = status;
1268
1269 __cpdma_chan_free(chan, desc, outlen, cb_status);
1270 return status;
1271
1272unlock_ret:
1273 spin_unlock_irqrestore(&chan->lock, flags);
1274 return status;
1275}
1276
1277int cpdma_chan_process(struct cpdma_chan *chan, int quota)
1278{
1279 int used = 0, ret = 0;
1280
1281 if (chan->state != CPDMA_STATE_ACTIVE)
1282 return -EINVAL;
1283
1284 while (used < quota) {
1285 ret = __cpdma_chan_process(chan);
1286 if (ret < 0)
1287 break;
1288 used++;
1289 }
1290 return used;
1291}
1292
1293int cpdma_chan_start(struct cpdma_chan *chan)
1294{
1295 struct cpdma_ctlr *ctlr = chan->ctlr;
1296 unsigned long flags;
1297 int ret;
1298
1299 spin_lock_irqsave(&ctlr->lock, flags);
1300 ret = cpdma_chan_set_chan_shaper(chan);
1301 spin_unlock_irqrestore(&ctlr->lock, flags);
1302 if (ret)
1303 return ret;
1304
1305 ret = cpdma_chan_on(chan);
1306 if (ret)
1307 return ret;
1308
1309 return 0;
1310}
1311
1312int cpdma_chan_stop(struct cpdma_chan *chan)
1313{
1314 struct cpdma_ctlr *ctlr = chan->ctlr;
1315 struct cpdma_desc_pool *pool = ctlr->pool;
1316 unsigned long flags;
1317 int ret;
1318 unsigned timeout;
1319
1320 spin_lock_irqsave(&chan->lock, flags);
1321 if (chan->state == CPDMA_STATE_TEARDOWN) {
1322 spin_unlock_irqrestore(&chan->lock, flags);
1323 return -EINVAL;
1324 }
1325
1326 chan->state = CPDMA_STATE_TEARDOWN;
1327 dma_reg_write(ctlr, chan->int_clear, chan->mask);
1328
1329 /* trigger teardown */
1330 dma_reg_write(ctlr, chan->td, chan_linear(chan));
1331
1332 /* wait for teardown complete */
1333 timeout = 100 * 100; /* 100 ms */
1334 while (timeout) {
1335 u32 cp = chan_read(chan, cp);
1336 if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
1337 break;
1338 udelay(10);
1339 timeout--;
1340 }
1341 WARN_ON(!timeout);
1342 chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
1343
1344 /* handle completed packets */
1345 spin_unlock_irqrestore(&chan->lock, flags);
1346 do {
1347 ret = __cpdma_chan_process(chan);
1348 if (ret < 0)
1349 break;
1350 } while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
1351 spin_lock_irqsave(&chan->lock, flags);
1352
1353 /* remaining packets haven't been tx/rx'ed, clean them up */
1354 while (chan->head) {
1355 struct cpdma_desc __iomem *desc = chan->head;
1356 dma_addr_t next_dma;
1357
1358 next_dma = desc_read(desc, hw_next);
1359 chan->head = desc_from_phys(pool, next_dma);
1360 chan->count--;
1361 chan->stats.teardown_dequeue++;
1362
1363 /* issue callback without locks held */
1364 spin_unlock_irqrestore(&chan->lock, flags);
1365 __cpdma_chan_free(chan, desc, 0, -ENOSYS);
1366 spin_lock_irqsave(&chan->lock, flags);
1367 }
1368
1369 chan->state = CPDMA_STATE_IDLE;
1370 spin_unlock_irqrestore(&chan->lock, flags);
1371 return 0;
1372}
1373
1374int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
1375{
1376 unsigned long flags;
1377
1378 spin_lock_irqsave(&chan->lock, flags);
1379 if (chan->state != CPDMA_STATE_ACTIVE) {
1380 spin_unlock_irqrestore(&chan->lock, flags);
1381 return -EINVAL;
1382 }
1383
1384 dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
1385 chan->mask);
1386 spin_unlock_irqrestore(&chan->lock, flags);
1387
1388 return 0;
1389}
1390
1391int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
1392{
1393 unsigned long flags;
1394 int ret;
1395
1396 spin_lock_irqsave(&ctlr->lock, flags);
1397 ret = _cpdma_control_get(ctlr, control);
1398 spin_unlock_irqrestore(&ctlr->lock, flags);
1399
1400 return ret;
1401}
1402
1403int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
1404{
1405 unsigned long flags;
1406 int ret;
1407
1408 spin_lock_irqsave(&ctlr->lock, flags);
1409 ret = _cpdma_control_set(ctlr, control, value);
1410 spin_unlock_irqrestore(&ctlr->lock, flags);
1411
1412 return ret;
1413}
1414
1415int cpdma_get_num_rx_descs(struct cpdma_ctlr *ctlr)
1416{
1417 return ctlr->num_rx_desc;
1418}
1419
1420int cpdma_get_num_tx_descs(struct cpdma_ctlr *ctlr)
1421{
1422 return ctlr->num_tx_desc;
1423}
1424
1425int cpdma_set_num_rx_descs(struct cpdma_ctlr *ctlr, int num_rx_desc)
1426{
1427 unsigned long flags;
1428 int temp, ret;
1429
1430 spin_lock_irqsave(&ctlr->lock, flags);
1431
1432 temp = ctlr->num_rx_desc;
1433 ctlr->num_rx_desc = num_rx_desc;
1434 ctlr->num_tx_desc = ctlr->pool->num_desc - ctlr->num_rx_desc;
1435 ret = cpdma_chan_split_pool(ctlr);
1436 if (ret) {
1437 ctlr->num_rx_desc = temp;
1438 ctlr->num_tx_desc = ctlr->pool->num_desc - ctlr->num_rx_desc;
1439 }
1440
1441 spin_unlock_irqrestore(&ctlr->lock, flags);
1442
1443 return ret;
1444}
1445

source code of linux/drivers/net/ethernet/ti/davinci_cpdma.c