1// SPDX-License-Identifier: GPL-2.0
2/*
3 * TUSB6010 USB 2.0 OTG Dual Role controller OMAP DMA interface
4 *
5 * Copyright (C) 2006 Nokia Corporation
6 * Tony Lindgren <tony@atomide.com>
7 */
8#include <linux/module.h>
9#include <linux/kernel.h>
10#include <linux/errno.h>
11#include <linux/usb.h>
12#include <linux/platform_device.h>
13#include <linux/dma-mapping.h>
14#include <linux/slab.h>
15#include <linux/dmaengine.h>
16
17#include "musb_core.h"
18#include "tusb6010.h"
19
20#define to_chdat(c) ((struct tusb_omap_dma_ch *)(c)->private_data)
21
22#define MAX_DMAREQ 5 /* REVISIT: Really 6, but req5 not OK */
23
24struct tusb_dma_data {
25 s8 dmareq;
26 struct dma_chan *chan;
27};
28
29struct tusb_omap_dma_ch {
30 struct musb *musb;
31 void __iomem *tbase;
32 unsigned long phys_offset;
33 int epnum;
34 u8 tx;
35 struct musb_hw_ep *hw_ep;
36
37 struct tusb_dma_data *dma_data;
38
39 struct tusb_omap_dma *tusb_dma;
40
41 dma_addr_t dma_addr;
42
43 u32 len;
44 u16 packet_sz;
45 u16 transfer_packet_sz;
46 u32 transfer_len;
47 u32 completed_len;
48};
49
50struct tusb_omap_dma {
51 struct dma_controller controller;
52 void __iomem *tbase;
53
54 struct tusb_dma_data dma_pool[MAX_DMAREQ];
55 unsigned multichannel:1;
56};
57
58/*
59 * Allocate dmareq0 to the current channel unless it's already taken
60 */
61static inline int tusb_omap_use_shared_dmareq(struct tusb_omap_dma_ch *chdat)
62{
63 u32 reg = musb_readl(addr: chdat->tbase, TUSB_DMA_EP_MAP);
64
65 if (reg != 0) {
66 dev_dbg(chdat->musb->controller, "ep%i dmareq0 is busy for ep%i\n",
67 chdat->epnum, reg & 0xf);
68 return -EAGAIN;
69 }
70
71 if (chdat->tx)
72 reg = (1 << 4) | chdat->epnum;
73 else
74 reg = chdat->epnum;
75
76 musb_writel(addr: chdat->tbase, TUSB_DMA_EP_MAP, data: reg);
77
78 return 0;
79}
80
81static inline void tusb_omap_free_shared_dmareq(struct tusb_omap_dma_ch *chdat)
82{
83 u32 reg = musb_readl(addr: chdat->tbase, TUSB_DMA_EP_MAP);
84
85 if ((reg & 0xf) != chdat->epnum) {
86 printk(KERN_ERR "ep%i trying to release dmareq0 for ep%i\n",
87 chdat->epnum, reg & 0xf);
88 return;
89 }
90 musb_writel(addr: chdat->tbase, TUSB_DMA_EP_MAP, data: 0);
91}
92
93/*
94 * See also musb_dma_completion in plat_uds.c and musb_g_[tx|rx]() in
95 * musb_gadget.c.
96 */
97static void tusb_omap_dma_cb(void *data)
98{
99 struct dma_channel *channel = (struct dma_channel *)data;
100 struct tusb_omap_dma_ch *chdat = to_chdat(channel);
101 struct tusb_omap_dma *tusb_dma = chdat->tusb_dma;
102 struct musb *musb = chdat->musb;
103 struct device *dev = musb->controller;
104 struct musb_hw_ep *hw_ep = chdat->hw_ep;
105 void __iomem *ep_conf = hw_ep->conf;
106 void __iomem *mbase = musb->mregs;
107 unsigned long remaining, flags, pio;
108
109 spin_lock_irqsave(&musb->lock, flags);
110
111 dev_dbg(musb->controller, "ep%i %s dma callback\n",
112 chdat->epnum, chdat->tx ? "tx" : "rx");
113
114 if (chdat->tx)
115 remaining = musb_readl(addr: ep_conf, TUSB_EP_TX_OFFSET);
116 else
117 remaining = musb_readl(addr: ep_conf, TUSB_EP_RX_OFFSET);
118
119 remaining = TUSB_EP_CONFIG_XFR_SIZE(remaining);
120
121 /* HW issue #10: XFR_SIZE may get corrupt on DMA (both async & sync) */
122 if (unlikely(remaining > chdat->transfer_len)) {
123 dev_dbg(musb->controller, "Corrupt %s XFR_SIZE: 0x%08lx\n",
124 chdat->tx ? "tx" : "rx", remaining);
125 remaining = 0;
126 }
127
128 channel->actual_len = chdat->transfer_len - remaining;
129 pio = chdat->len - channel->actual_len;
130
131 dev_dbg(musb->controller, "DMA remaining %lu/%u\n", remaining, chdat->transfer_len);
132
133 /* Transfer remaining 1 - 31 bytes */
134 if (pio > 0 && pio < 32) {
135 u8 *buf;
136
137 dev_dbg(musb->controller, "Using PIO for remaining %lu bytes\n", pio);
138 buf = phys_to_virt(address: (u32)chdat->dma_addr) + chdat->transfer_len;
139 if (chdat->tx) {
140 dma_unmap_single(dev, chdat->dma_addr,
141 chdat->transfer_len,
142 DMA_TO_DEVICE);
143 musb_write_fifo(ep: hw_ep, len: pio, src: buf);
144 } else {
145 dma_unmap_single(dev, chdat->dma_addr,
146 chdat->transfer_len,
147 DMA_FROM_DEVICE);
148 musb_read_fifo(ep: hw_ep, len: pio, dst: buf);
149 }
150 channel->actual_len += pio;
151 }
152
153 if (!tusb_dma->multichannel)
154 tusb_omap_free_shared_dmareq(chdat);
155
156 channel->status = MUSB_DMA_STATUS_FREE;
157
158 musb_dma_completion(musb, epnum: chdat->epnum, transmit: chdat->tx);
159
160 /* We must terminate short tx transfers manually by setting TXPKTRDY.
161 * REVISIT: This same problem may occur with other MUSB dma as well.
162 * Easy to test with g_ether by pinging the MUSB board with ping -s54.
163 */
164 if ((chdat->transfer_len < chdat->packet_sz)
165 || (chdat->transfer_len % chdat->packet_sz != 0)) {
166 u16 csr;
167
168 if (chdat->tx) {
169 dev_dbg(musb->controller, "terminating short tx packet\n");
170 musb_ep_select(mbase, chdat->epnum);
171 csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
172 csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY
173 | MUSB_TXCSR_P_WZC_BITS;
174 musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
175 }
176 }
177
178 spin_unlock_irqrestore(lock: &musb->lock, flags);
179}
180
181static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
182 u8 rndis_mode, dma_addr_t dma_addr, u32 len)
183{
184 struct tusb_omap_dma_ch *chdat = to_chdat(channel);
185 struct tusb_omap_dma *tusb_dma = chdat->tusb_dma;
186 struct musb *musb = chdat->musb;
187 struct device *dev = musb->controller;
188 struct musb_hw_ep *hw_ep = chdat->hw_ep;
189 void __iomem *mbase = musb->mregs;
190 void __iomem *ep_conf = hw_ep->conf;
191 dma_addr_t fifo_addr = hw_ep->fifo_sync;
192 u32 dma_remaining;
193 u16 csr;
194 u32 psize;
195 struct tusb_dma_data *dma_data;
196 struct dma_async_tx_descriptor *dma_desc;
197 struct dma_slave_config dma_cfg;
198 enum dma_transfer_direction dma_dir;
199 u32 port_window;
200 int ret;
201
202 if (unlikely(dma_addr & 0x1) || (len < 32) || (len > packet_sz))
203 return false;
204
205 /*
206 * HW issue #10: Async dma will eventually corrupt the XFR_SIZE
207 * register which will cause missed DMA interrupt. We could try to
208 * use a timer for the callback, but it is unsafe as the XFR_SIZE
209 * register is corrupt, and we won't know if the DMA worked.
210 */
211 if (dma_addr & 0x2)
212 return false;
213
214 /*
215 * Because of HW issue #10, it seems like mixing sync DMA and async
216 * PIO access can confuse the DMA. Make sure XFR_SIZE is reset before
217 * using the channel for DMA.
218 */
219 if (chdat->tx)
220 dma_remaining = musb_readl(addr: ep_conf, TUSB_EP_TX_OFFSET);
221 else
222 dma_remaining = musb_readl(addr: ep_conf, TUSB_EP_RX_OFFSET);
223
224 dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
225 if (dma_remaining) {
226 dev_dbg(musb->controller, "Busy %s dma, not using: %08x\n",
227 chdat->tx ? "tx" : "rx", dma_remaining);
228 return false;
229 }
230
231 chdat->transfer_len = len & ~0x1f;
232
233 if (len < packet_sz)
234 chdat->transfer_packet_sz = chdat->transfer_len;
235 else
236 chdat->transfer_packet_sz = packet_sz;
237
238 dma_data = chdat->dma_data;
239 if (!tusb_dma->multichannel) {
240 if (tusb_omap_use_shared_dmareq(chdat) != 0) {
241 dev_dbg(musb->controller, "could not get dma for ep%i\n", chdat->epnum);
242 return false;
243 }
244 if (dma_data->dmareq < 0) {
245 /* REVISIT: This should get blocked earlier, happens
246 * with MSC ErrorRecoveryTest
247 */
248 WARN_ON(1);
249 return false;
250 }
251 }
252
253 chdat->packet_sz = packet_sz;
254 chdat->len = len;
255 channel->actual_len = 0;
256 chdat->dma_addr = dma_addr;
257 channel->status = MUSB_DMA_STATUS_BUSY;
258
259 /* Since we're recycling dma areas, we need to clean or invalidate */
260 if (chdat->tx) {
261 dma_dir = DMA_MEM_TO_DEV;
262 dma_map_single(dev, phys_to_virt(dma_addr), len,
263 DMA_TO_DEVICE);
264 } else {
265 dma_dir = DMA_DEV_TO_MEM;
266 dma_map_single(dev, phys_to_virt(dma_addr), len,
267 DMA_FROM_DEVICE);
268 }
269
270 memset(&dma_cfg, 0, sizeof(dma_cfg));
271
272 /* Use 16-bit transfer if dma_addr is not 32-bit aligned */
273 if ((dma_addr & 0x3) == 0) {
274 dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
275 dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
276 port_window = 8;
277 } else {
278 dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
279 dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
280 port_window = 16;
281
282 fifo_addr = hw_ep->fifo_async;
283 }
284
285 dev_dbg(musb->controller,
286 "ep%i %s dma: %pad len: %u(%u) packet_sz: %i(%i)\n",
287 chdat->epnum, chdat->tx ? "tx" : "rx", &dma_addr,
288 chdat->transfer_len, len, chdat->transfer_packet_sz, packet_sz);
289
290 dma_cfg.src_addr = fifo_addr;
291 dma_cfg.dst_addr = fifo_addr;
292 dma_cfg.src_port_window_size = port_window;
293 dma_cfg.src_maxburst = port_window;
294 dma_cfg.dst_port_window_size = port_window;
295 dma_cfg.dst_maxburst = port_window;
296
297 ret = dmaengine_slave_config(chan: dma_data->chan, config: &dma_cfg);
298 if (ret) {
299 dev_err(musb->controller, "DMA slave config failed: %d\n", ret);
300 return false;
301 }
302
303 dma_desc = dmaengine_prep_slave_single(chan: dma_data->chan, buf: dma_addr,
304 len: chdat->transfer_len, dir: dma_dir,
305 flags: DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
306 if (!dma_desc) {
307 dev_err(musb->controller, "DMA prep_slave_single failed\n");
308 return false;
309 }
310
311 dma_desc->callback = tusb_omap_dma_cb;
312 dma_desc->callback_param = channel;
313 dmaengine_submit(desc: dma_desc);
314
315 dev_dbg(musb->controller,
316 "ep%i %s using %i-bit %s dma from %pad to %pad\n",
317 chdat->epnum, chdat->tx ? "tx" : "rx",
318 dma_cfg.src_addr_width * 8,
319 ((dma_addr & 0x3) == 0) ? "sync" : "async",
320 (dma_dir == DMA_MEM_TO_DEV) ? &dma_addr : &fifo_addr,
321 (dma_dir == DMA_MEM_TO_DEV) ? &fifo_addr : &dma_addr);
322
323 /*
324 * Prepare MUSB for DMA transfer
325 */
326 musb_ep_select(mbase, chdat->epnum);
327 if (chdat->tx) {
328 csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
329 csr |= (MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB
330 | MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
331 csr &= ~MUSB_TXCSR_P_UNDERRUN;
332 musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
333 } else {
334 csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
335 csr |= MUSB_RXCSR_DMAENAB;
336 csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAMODE);
337 musb_writew(hw_ep->regs, MUSB_RXCSR,
338 csr | MUSB_RXCSR_P_WZC_BITS);
339 }
340
341 /* Start DMA transfer */
342 dma_async_issue_pending(chan: dma_data->chan);
343
344 if (chdat->tx) {
345 /* Send transfer_packet_sz packets at a time */
346 psize = musb_readl(addr: ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET);
347 psize &= ~0x7ff;
348 psize |= chdat->transfer_packet_sz;
349 musb_writel(addr: ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET, data: psize);
350
351 musb_writel(addr: ep_conf, TUSB_EP_TX_OFFSET,
352 TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
353 } else {
354 /* Receive transfer_packet_sz packets at a time */
355 psize = musb_readl(addr: ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET);
356 psize &= ~(0x7ff << 16);
357 psize |= (chdat->transfer_packet_sz << 16);
358 musb_writel(addr: ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET, data: psize);
359
360 musb_writel(addr: ep_conf, TUSB_EP_RX_OFFSET,
361 TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
362 }
363
364 return true;
365}
366
367static int tusb_omap_dma_abort(struct dma_channel *channel)
368{
369 struct tusb_omap_dma_ch *chdat = to_chdat(channel);
370
371 if (chdat->dma_data)
372 dmaengine_terminate_all(chan: chdat->dma_data->chan);
373
374 channel->status = MUSB_DMA_STATUS_FREE;
375
376 return 0;
377}
378
379static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
380{
381 u32 reg = musb_readl(addr: chdat->tbase, TUSB_DMA_EP_MAP);
382 int i, dmareq_nr = -1;
383
384 for (i = 0; i < MAX_DMAREQ; i++) {
385 int cur = (reg & (0xf << (i * 5))) >> (i * 5);
386 if (cur == 0) {
387 dmareq_nr = i;
388 break;
389 }
390 }
391
392 if (dmareq_nr == -1)
393 return -EAGAIN;
394
395 reg |= (chdat->epnum << (dmareq_nr * 5));
396 if (chdat->tx)
397 reg |= ((1 << 4) << (dmareq_nr * 5));
398 musb_writel(addr: chdat->tbase, TUSB_DMA_EP_MAP, data: reg);
399
400 chdat->dma_data = &chdat->tusb_dma->dma_pool[dmareq_nr];
401
402 return 0;
403}
404
405static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
406{
407 u32 reg;
408
409 if (!chdat || !chdat->dma_data || chdat->dma_data->dmareq < 0)
410 return;
411
412 reg = musb_readl(addr: chdat->tbase, TUSB_DMA_EP_MAP);
413 reg &= ~(0x1f << (chdat->dma_data->dmareq * 5));
414 musb_writel(addr: chdat->tbase, TUSB_DMA_EP_MAP, data: reg);
415
416 chdat->dma_data = NULL;
417}
418
419static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
420
421static struct dma_channel *
422tusb_omap_dma_allocate(struct dma_controller *c,
423 struct musb_hw_ep *hw_ep,
424 u8 tx)
425{
426 int ret, i;
427 struct tusb_omap_dma *tusb_dma;
428 struct musb *musb;
429 struct dma_channel *channel = NULL;
430 struct tusb_omap_dma_ch *chdat = NULL;
431 struct tusb_dma_data *dma_data = NULL;
432
433 tusb_dma = container_of(c, struct tusb_omap_dma, controller);
434 musb = tusb_dma->controller.musb;
435
436 /* REVISIT: Why does dmareq5 not work? */
437 if (hw_ep->epnum == 0) {
438 dev_dbg(musb->controller, "Not allowing DMA for ep0 %s\n", tx ? "tx" : "rx");
439 return NULL;
440 }
441
442 for (i = 0; i < MAX_DMAREQ; i++) {
443 struct dma_channel *ch = dma_channel_pool[i];
444 if (ch->status == MUSB_DMA_STATUS_UNKNOWN) {
445 ch->status = MUSB_DMA_STATUS_FREE;
446 channel = ch;
447 chdat = ch->private_data;
448 break;
449 }
450 }
451
452 if (!channel)
453 return NULL;
454
455 chdat->musb = tusb_dma->controller.musb;
456 chdat->tbase = tusb_dma->tbase;
457 chdat->hw_ep = hw_ep;
458 chdat->epnum = hw_ep->epnum;
459 chdat->completed_len = 0;
460 chdat->tusb_dma = tusb_dma;
461 if (tx)
462 chdat->tx = 1;
463 else
464 chdat->tx = 0;
465
466 channel->max_len = 0x7fffffff;
467 channel->desired_mode = 0;
468 channel->actual_len = 0;
469
470 if (!chdat->dma_data) {
471 if (tusb_dma->multichannel) {
472 ret = tusb_omap_dma_allocate_dmareq(chdat);
473 if (ret != 0)
474 goto free_dmareq;
475 } else {
476 chdat->dma_data = &tusb_dma->dma_pool[0];
477 }
478 }
479
480 dma_data = chdat->dma_data;
481
482 dev_dbg(musb->controller, "ep%i %s dma: %s dmareq%i\n",
483 chdat->epnum,
484 chdat->tx ? "tx" : "rx",
485 tusb_dma->multichannel ? "shared" : "dedicated",
486 dma_data->dmareq);
487
488 return channel;
489
490free_dmareq:
491 tusb_omap_dma_free_dmareq(chdat);
492
493 dev_dbg(musb->controller, "ep%i: Could not get a DMA channel\n", chdat->epnum);
494 channel->status = MUSB_DMA_STATUS_UNKNOWN;
495
496 return NULL;
497}
498
499static void tusb_omap_dma_release(struct dma_channel *channel)
500{
501 struct tusb_omap_dma_ch *chdat = to_chdat(channel);
502 struct musb *musb = chdat->musb;
503
504 dev_dbg(musb->controller, "Release for ep%i\n", chdat->epnum);
505
506 channel->status = MUSB_DMA_STATUS_UNKNOWN;
507
508 dmaengine_terminate_sync(chan: chdat->dma_data->chan);
509 tusb_omap_dma_free_dmareq(chdat);
510
511 channel = NULL;
512}
513
514void tusb_dma_controller_destroy(struct dma_controller *c)
515{
516 struct tusb_omap_dma *tusb_dma;
517 int i;
518
519 tusb_dma = container_of(c, struct tusb_omap_dma, controller);
520 for (i = 0; i < MAX_DMAREQ; i++) {
521 struct dma_channel *ch = dma_channel_pool[i];
522 if (ch) {
523 kfree(objp: ch->private_data);
524 kfree(objp: ch);
525 }
526
527 /* Free up the DMA channels */
528 if (tusb_dma && tusb_dma->dma_pool[i].chan)
529 dma_release_channel(chan: tusb_dma->dma_pool[i].chan);
530 }
531
532 kfree(objp: tusb_dma);
533}
534EXPORT_SYMBOL_GPL(tusb_dma_controller_destroy);
535
536static int tusb_omap_allocate_dma_pool(struct tusb_omap_dma *tusb_dma)
537{
538 struct musb *musb = tusb_dma->controller.musb;
539 int i;
540 int ret = 0;
541
542 for (i = 0; i < MAX_DMAREQ; i++) {
543 struct tusb_dma_data *dma_data = &tusb_dma->dma_pool[i];
544
545 /*
546 * Request DMA channels:
547 * - one channel in case of non multichannel mode
548 * - MAX_DMAREQ number of channels in multichannel mode
549 */
550 if (i == 0 || tusb_dma->multichannel) {
551 char ch_name[8];
552
553 sprintf(buf: ch_name, fmt: "dmareq%d", i);
554 dma_data->chan = dma_request_chan(dev: musb->controller,
555 name: ch_name);
556 if (IS_ERR(ptr: dma_data->chan)) {
557 dev_err(musb->controller,
558 "Failed to request %s\n", ch_name);
559 ret = PTR_ERR(ptr: dma_data->chan);
560 goto dma_error;
561 }
562
563 dma_data->dmareq = i;
564 } else {
565 dma_data->dmareq = -1;
566 }
567 }
568
569 return 0;
570
571dma_error:
572 for (; i >= 0; i--) {
573 struct tusb_dma_data *dma_data = &tusb_dma->dma_pool[i];
574
575 if (dma_data->dmareq >= 0)
576 dma_release_channel(chan: dma_data->chan);
577 }
578
579 return ret;
580}
581
582struct dma_controller *
583tusb_dma_controller_create(struct musb *musb, void __iomem *base)
584{
585 void __iomem *tbase = musb->ctrl_base;
586 struct tusb_omap_dma *tusb_dma;
587 int i;
588
589 /* REVISIT: Get dmareq lines used from board-*.c */
590
591 musb_writel(addr: musb->ctrl_base, TUSB_DMA_INT_MASK, data: 0x7fffffff);
592 musb_writel(addr: musb->ctrl_base, TUSB_DMA_EP_MAP, data: 0);
593
594 musb_writel(addr: tbase, TUSB_DMA_REQ_CONF,
595 TUSB_DMA_REQ_CONF_BURST_SIZE(2)
596 | TUSB_DMA_REQ_CONF_DMA_REQ_EN(0x3f)
597 | TUSB_DMA_REQ_CONF_DMA_REQ_ASSER(2));
598
599 tusb_dma = kzalloc(size: sizeof(struct tusb_omap_dma), GFP_KERNEL);
600 if (!tusb_dma)
601 goto out;
602
603 tusb_dma->controller.musb = musb;
604 tusb_dma->tbase = musb->ctrl_base;
605
606 tusb_dma->controller.channel_alloc = tusb_omap_dma_allocate;
607 tusb_dma->controller.channel_release = tusb_omap_dma_release;
608 tusb_dma->controller.channel_program = tusb_omap_dma_program;
609 tusb_dma->controller.channel_abort = tusb_omap_dma_abort;
610
611 if (musb->tusb_revision >= TUSB_REV_30)
612 tusb_dma->multichannel = 1;
613
614 for (i = 0; i < MAX_DMAREQ; i++) {
615 struct dma_channel *ch;
616 struct tusb_omap_dma_ch *chdat;
617
618 ch = kzalloc(size: sizeof(struct dma_channel), GFP_KERNEL);
619 if (!ch)
620 goto cleanup;
621
622 dma_channel_pool[i] = ch;
623
624 chdat = kzalloc(size: sizeof(struct tusb_omap_dma_ch), GFP_KERNEL);
625 if (!chdat)
626 goto cleanup;
627
628 ch->status = MUSB_DMA_STATUS_UNKNOWN;
629 ch->private_data = chdat;
630 }
631
632 if (tusb_omap_allocate_dma_pool(tusb_dma))
633 goto cleanup;
634
635 return &tusb_dma->controller;
636
637cleanup:
638 musb_dma_controller_destroy(d: &tusb_dma->controller);
639out:
640 return NULL;
641}
642EXPORT_SYMBOL_GPL(tusb_dma_controller_create);
643

source code of linux/drivers/usb/musb/tusb6010_omap.c