xref: /linux/drivers/usb/musb/tusb6010_omap.c (revision c98be0c96db00e9b6b02d31e0fa7590c54cdaaac)
1 /*
2  * TUSB6010 USB 2.0 OTG Dual Role controller OMAP DMA interface
3  *
4  * Copyright (C) 2006 Nokia Corporation
5  * Tony Lindgren <tony@atomide.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/usb.h>
15 #include <linux/platform_device.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/slab.h>
18 #include <linux/omap-dma.h>
19 
20 #include "musb_core.h"
21 #include "tusb6010.h"
22 
23 #define to_chdat(c)		((struct tusb_omap_dma_ch *)(c)->private_data)
24 
25 #define MAX_DMAREQ		5	/* REVISIT: Really 6, but req5 not OK */
26 
27 #define OMAP24XX_DMA_EXT_DMAREQ0	2
28 #define OMAP24XX_DMA_EXT_DMAREQ1	3
29 #define OMAP242X_DMA_EXT_DMAREQ2	14
30 #define OMAP242X_DMA_EXT_DMAREQ3	15
31 #define OMAP242X_DMA_EXT_DMAREQ4	16
32 #define OMAP242X_DMA_EXT_DMAREQ5	64
33 
34 struct tusb_omap_dma_ch {
35 	struct musb		*musb;
36 	void __iomem		*tbase;
37 	unsigned long		phys_offset;
38 	int			epnum;
39 	u8			tx;
40 	struct musb_hw_ep	*hw_ep;
41 
42 	int			ch;
43 	s8			dmareq;
44 	s8			sync_dev;
45 
46 	struct tusb_omap_dma	*tusb_dma;
47 
48 	dma_addr_t		dma_addr;
49 
50 	u32			len;
51 	u16			packet_sz;
52 	u16			transfer_packet_sz;
53 	u32			transfer_len;
54 	u32			completed_len;
55 };
56 
57 struct tusb_omap_dma {
58 	struct dma_controller		controller;
59 	struct musb			*musb;
60 	void __iomem			*tbase;
61 
62 	int				ch;
63 	s8				dmareq;
64 	s8				sync_dev;
65 	unsigned			multichannel:1;
66 };
67 
68 /*
69  * Allocate dmareq0 to the current channel unless it's already taken
70  */
71 static inline int tusb_omap_use_shared_dmareq(struct tusb_omap_dma_ch *chdat)
72 {
73 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
74 
75 	if (reg != 0) {
76 		dev_dbg(chdat->musb->controller, "ep%i dmareq0 is busy for ep%i\n",
77 			chdat->epnum, reg & 0xf);
78 		return -EAGAIN;
79 	}
80 
81 	if (chdat->tx)
82 		reg = (1 << 4) | chdat->epnum;
83 	else
84 		reg = chdat->epnum;
85 
86 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
87 
88 	return 0;
89 }
90 
91 static inline void tusb_omap_free_shared_dmareq(struct tusb_omap_dma_ch *chdat)
92 {
93 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
94 
95 	if ((reg & 0xf) != chdat->epnum) {
96 		printk(KERN_ERR "ep%i trying to release dmareq0 for ep%i\n",
97 			chdat->epnum, reg & 0xf);
98 		return;
99 	}
100 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, 0);
101 }
102 
103 /*
104  * See also musb_dma_completion in plat_uds.c and musb_g_[tx|rx]() in
105  * musb_gadget.c.
106  */
107 static void tusb_omap_dma_cb(int lch, u16 ch_status, void *data)
108 {
109 	struct dma_channel	*channel = (struct dma_channel *)data;
110 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
111 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
112 	struct musb		*musb = chdat->musb;
113 	struct device		*dev = musb->controller;
114 	struct musb_hw_ep	*hw_ep = chdat->hw_ep;
115 	void __iomem		*ep_conf = hw_ep->conf;
116 	void __iomem		*mbase = musb->mregs;
117 	unsigned long		remaining, flags, pio;
118 	int			ch;
119 
120 	spin_lock_irqsave(&musb->lock, flags);
121 
122 	if (tusb_dma->multichannel)
123 		ch = chdat->ch;
124 	else
125 		ch = tusb_dma->ch;
126 
127 	if (ch_status != OMAP_DMA_BLOCK_IRQ)
128 		printk(KERN_ERR "TUSB DMA error status: %i\n", ch_status);
129 
130 	dev_dbg(musb->controller, "ep%i %s dma callback ch: %i status: %x\n",
131 		chdat->epnum, chdat->tx ? "tx" : "rx",
132 		ch, ch_status);
133 
134 	if (chdat->tx)
135 		remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
136 	else
137 		remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
138 
139 	remaining = TUSB_EP_CONFIG_XFR_SIZE(remaining);
140 
141 	/* HW issue #10: XFR_SIZE may get corrupt on DMA (both async & sync) */
142 	if (unlikely(remaining > chdat->transfer_len)) {
143 		dev_dbg(musb->controller, "Corrupt %s dma ch%i XFR_SIZE: 0x%08lx\n",
144 			chdat->tx ? "tx" : "rx", chdat->ch,
145 			remaining);
146 		remaining = 0;
147 	}
148 
149 	channel->actual_len = chdat->transfer_len - remaining;
150 	pio = chdat->len - channel->actual_len;
151 
152 	dev_dbg(musb->controller, "DMA remaining %lu/%u\n", remaining, chdat->transfer_len);
153 
154 	/* Transfer remaining 1 - 31 bytes */
155 	if (pio > 0 && pio < 32) {
156 		u8	*buf;
157 
158 		dev_dbg(musb->controller, "Using PIO for remaining %lu bytes\n", pio);
159 		buf = phys_to_virt((u32)chdat->dma_addr) + chdat->transfer_len;
160 		if (chdat->tx) {
161 			dma_unmap_single(dev, chdat->dma_addr,
162 						chdat->transfer_len,
163 						DMA_TO_DEVICE);
164 			musb_write_fifo(hw_ep, pio, buf);
165 		} else {
166 			dma_unmap_single(dev, chdat->dma_addr,
167 						chdat->transfer_len,
168 						DMA_FROM_DEVICE);
169 			musb_read_fifo(hw_ep, pio, buf);
170 		}
171 		channel->actual_len += pio;
172 	}
173 
174 	if (!tusb_dma->multichannel)
175 		tusb_omap_free_shared_dmareq(chdat);
176 
177 	channel->status = MUSB_DMA_STATUS_FREE;
178 
179 	/* Handle only RX callbacks here. TX callbacks must be handled based
180 	 * on the TUSB DMA status interrupt.
181 	 * REVISIT: Use both TUSB DMA status interrupt and OMAP DMA callback
182 	 * interrupt for RX and TX.
183 	 */
184 	if (!chdat->tx)
185 		musb_dma_completion(musb, chdat->epnum, chdat->tx);
186 
187 	/* We must terminate short tx transfers manually by setting TXPKTRDY.
188 	 * REVISIT: This same problem may occur with other MUSB dma as well.
189 	 * Easy to test with g_ether by pinging the MUSB board with ping -s54.
190 	 */
191 	if ((chdat->transfer_len < chdat->packet_sz)
192 			|| (chdat->transfer_len % chdat->packet_sz != 0)) {
193 		u16	csr;
194 
195 		if (chdat->tx) {
196 			dev_dbg(musb->controller, "terminating short tx packet\n");
197 			musb_ep_select(mbase, chdat->epnum);
198 			csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
199 			csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY
200 				| MUSB_TXCSR_P_WZC_BITS;
201 			musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
202 		}
203 	}
204 
205 	spin_unlock_irqrestore(&musb->lock, flags);
206 }
207 
208 static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
209 				u8 rndis_mode, dma_addr_t dma_addr, u32 len)
210 {
211 	struct tusb_omap_dma_ch		*chdat = to_chdat(channel);
212 	struct tusb_omap_dma		*tusb_dma = chdat->tusb_dma;
213 	struct musb			*musb = chdat->musb;
214 	struct device			*dev = musb->controller;
215 	struct musb_hw_ep		*hw_ep = chdat->hw_ep;
216 	void __iomem			*mbase = musb->mregs;
217 	void __iomem			*ep_conf = hw_ep->conf;
218 	dma_addr_t			fifo = hw_ep->fifo_sync;
219 	struct omap_dma_channel_params	dma_params;
220 	u32				dma_remaining;
221 	int				src_burst, dst_burst;
222 	u16				csr;
223 	int				ch;
224 	s8				dmareq;
225 	s8				sync_dev;
226 
227 	if (unlikely(dma_addr & 0x1) || (len < 32) || (len > packet_sz))
228 		return false;
229 
230 	/*
231 	 * HW issue #10: Async dma will eventually corrupt the XFR_SIZE
232 	 * register which will cause missed DMA interrupt. We could try to
233 	 * use a timer for the callback, but it is unsafe as the XFR_SIZE
234 	 * register is corrupt, and we won't know if the DMA worked.
235 	 */
236 	if (dma_addr & 0x2)
237 		return false;
238 
239 	/*
240 	 * Because of HW issue #10, it seems like mixing sync DMA and async
241 	 * PIO access can confuse the DMA. Make sure XFR_SIZE is reset before
242 	 * using the channel for DMA.
243 	 */
244 	if (chdat->tx)
245 		dma_remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
246 	else
247 		dma_remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
248 
249 	dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
250 	if (dma_remaining) {
251 		dev_dbg(musb->controller, "Busy %s dma ch%i, not using: %08x\n",
252 			chdat->tx ? "tx" : "rx", chdat->ch,
253 			dma_remaining);
254 		return false;
255 	}
256 
257 	chdat->transfer_len = len & ~0x1f;
258 
259 	if (len < packet_sz)
260 		chdat->transfer_packet_sz = chdat->transfer_len;
261 	else
262 		chdat->transfer_packet_sz = packet_sz;
263 
264 	if (tusb_dma->multichannel) {
265 		ch = chdat->ch;
266 		dmareq = chdat->dmareq;
267 		sync_dev = chdat->sync_dev;
268 	} else {
269 		if (tusb_omap_use_shared_dmareq(chdat) != 0) {
270 			dev_dbg(musb->controller, "could not get dma for ep%i\n", chdat->epnum);
271 			return false;
272 		}
273 		if (tusb_dma->ch < 0) {
274 			/* REVISIT: This should get blocked earlier, happens
275 			 * with MSC ErrorRecoveryTest
276 			 */
277 			WARN_ON(1);
278 			return false;
279 		}
280 
281 		ch = tusb_dma->ch;
282 		dmareq = tusb_dma->dmareq;
283 		sync_dev = tusb_dma->sync_dev;
284 		omap_set_dma_callback(ch, tusb_omap_dma_cb, channel);
285 	}
286 
287 	chdat->packet_sz = packet_sz;
288 	chdat->len = len;
289 	channel->actual_len = 0;
290 	chdat->dma_addr = dma_addr;
291 	channel->status = MUSB_DMA_STATUS_BUSY;
292 
293 	/* Since we're recycling dma areas, we need to clean or invalidate */
294 	if (chdat->tx)
295 		dma_map_single(dev, phys_to_virt(dma_addr), len,
296 				DMA_TO_DEVICE);
297 	else
298 		dma_map_single(dev, phys_to_virt(dma_addr), len,
299 				DMA_FROM_DEVICE);
300 
301 	/* Use 16-bit transfer if dma_addr is not 32-bit aligned */
302 	if ((dma_addr & 0x3) == 0) {
303 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S32;
304 		dma_params.elem_count = 8;		/* Elements in frame */
305 	} else {
306 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
307 		dma_params.elem_count = 16;		/* Elements in frame */
308 		fifo = hw_ep->fifo_async;
309 	}
310 
311 	dma_params.frame_count	= chdat->transfer_len / 32; /* Burst sz frame */
312 
313 	dev_dbg(musb->controller, "ep%i %s dma ch%i dma: %08x len: %u(%u) packet_sz: %i(%i)\n",
314 		chdat->epnum, chdat->tx ? "tx" : "rx",
315 		ch, dma_addr, chdat->transfer_len, len,
316 		chdat->transfer_packet_sz, packet_sz);
317 
318 	/*
319 	 * Prepare omap DMA for transfer
320 	 */
321 	if (chdat->tx) {
322 		dma_params.src_amode	= OMAP_DMA_AMODE_POST_INC;
323 		dma_params.src_start	= (unsigned long)dma_addr;
324 		dma_params.src_ei	= 0;
325 		dma_params.src_fi	= 0;
326 
327 		dma_params.dst_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
328 		dma_params.dst_start	= (unsigned long)fifo;
329 		dma_params.dst_ei	= 1;
330 		dma_params.dst_fi	= -31;	/* Loop 32 byte window */
331 
332 		dma_params.trigger	= sync_dev;
333 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
334 		dma_params.src_or_dst_synch	= 0;	/* Dest sync */
335 
336 		src_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 read */
337 		dst_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 write */
338 	} else {
339 		dma_params.src_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
340 		dma_params.src_start	= (unsigned long)fifo;
341 		dma_params.src_ei	= 1;
342 		dma_params.src_fi	= -31;	/* Loop 32 byte window */
343 
344 		dma_params.dst_amode	= OMAP_DMA_AMODE_POST_INC;
345 		dma_params.dst_start	= (unsigned long)dma_addr;
346 		dma_params.dst_ei	= 0;
347 		dma_params.dst_fi	= 0;
348 
349 		dma_params.trigger	= sync_dev;
350 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
351 		dma_params.src_or_dst_synch	= 1;	/* Source sync */
352 
353 		src_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 read */
354 		dst_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 write */
355 	}
356 
357 	dev_dbg(musb->controller, "ep%i %s using %i-bit %s dma from 0x%08lx to 0x%08lx\n",
358 		chdat->epnum, chdat->tx ? "tx" : "rx",
359 		(dma_params.data_type == OMAP_DMA_DATA_TYPE_S32) ? 32 : 16,
360 		((dma_addr & 0x3) == 0) ? "sync" : "async",
361 		dma_params.src_start, dma_params.dst_start);
362 
363 	omap_set_dma_params(ch, &dma_params);
364 	omap_set_dma_src_burst_mode(ch, src_burst);
365 	omap_set_dma_dest_burst_mode(ch, dst_burst);
366 	omap_set_dma_write_mode(ch, OMAP_DMA_WRITE_LAST_NON_POSTED);
367 
368 	/*
369 	 * Prepare MUSB for DMA transfer
370 	 */
371 	if (chdat->tx) {
372 		musb_ep_select(mbase, chdat->epnum);
373 		csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
374 		csr |= (MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB
375 			| MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
376 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
377 		musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
378 	} else {
379 		musb_ep_select(mbase, chdat->epnum);
380 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
381 		csr |= MUSB_RXCSR_DMAENAB;
382 		csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAMODE);
383 		musb_writew(hw_ep->regs, MUSB_RXCSR,
384 			csr | MUSB_RXCSR_P_WZC_BITS);
385 	}
386 
387 	/*
388 	 * Start DMA transfer
389 	 */
390 	omap_start_dma(ch);
391 
392 	if (chdat->tx) {
393 		/* Send transfer_packet_sz packets at a time */
394 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
395 			chdat->transfer_packet_sz);
396 
397 		musb_writel(ep_conf, TUSB_EP_TX_OFFSET,
398 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
399 	} else {
400 		/* Receive transfer_packet_sz packets at a time */
401 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
402 			chdat->transfer_packet_sz << 16);
403 
404 		musb_writel(ep_conf, TUSB_EP_RX_OFFSET,
405 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
406 	}
407 
408 	return true;
409 }
410 
411 static int tusb_omap_dma_abort(struct dma_channel *channel)
412 {
413 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
414 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
415 
416 	if (!tusb_dma->multichannel) {
417 		if (tusb_dma->ch >= 0) {
418 			omap_stop_dma(tusb_dma->ch);
419 			omap_free_dma(tusb_dma->ch);
420 			tusb_dma->ch = -1;
421 		}
422 
423 		tusb_dma->dmareq = -1;
424 		tusb_dma->sync_dev = -1;
425 	}
426 
427 	channel->status = MUSB_DMA_STATUS_FREE;
428 
429 	return 0;
430 }
431 
432 static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
433 {
434 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
435 	int		i, dmareq_nr = -1;
436 
437 	const int sync_dev[6] = {
438 		OMAP24XX_DMA_EXT_DMAREQ0,
439 		OMAP24XX_DMA_EXT_DMAREQ1,
440 		OMAP242X_DMA_EXT_DMAREQ2,
441 		OMAP242X_DMA_EXT_DMAREQ3,
442 		OMAP242X_DMA_EXT_DMAREQ4,
443 		OMAP242X_DMA_EXT_DMAREQ5,
444 	};
445 
446 	for (i = 0; i < MAX_DMAREQ; i++) {
447 		int cur = (reg & (0xf << (i * 5))) >> (i * 5);
448 		if (cur == 0) {
449 			dmareq_nr = i;
450 			break;
451 		}
452 	}
453 
454 	if (dmareq_nr == -1)
455 		return -EAGAIN;
456 
457 	reg |= (chdat->epnum << (dmareq_nr * 5));
458 	if (chdat->tx)
459 		reg |= ((1 << 4) << (dmareq_nr * 5));
460 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
461 
462 	chdat->dmareq = dmareq_nr;
463 	chdat->sync_dev = sync_dev[chdat->dmareq];
464 
465 	return 0;
466 }
467 
468 static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
469 {
470 	u32 reg;
471 
472 	if (!chdat || chdat->dmareq < 0)
473 		return;
474 
475 	reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
476 	reg &= ~(0x1f << (chdat->dmareq * 5));
477 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
478 
479 	chdat->dmareq = -1;
480 	chdat->sync_dev = -1;
481 }
482 
483 static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
484 
485 static struct dma_channel *
486 tusb_omap_dma_allocate(struct dma_controller *c,
487 		struct musb_hw_ep *hw_ep,
488 		u8 tx)
489 {
490 	int ret, i;
491 	const char		*dev_name;
492 	struct tusb_omap_dma	*tusb_dma;
493 	struct musb		*musb;
494 	void __iomem		*tbase;
495 	struct dma_channel	*channel = NULL;
496 	struct tusb_omap_dma_ch	*chdat = NULL;
497 	u32			reg;
498 
499 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
500 	musb = tusb_dma->musb;
501 	tbase = musb->ctrl_base;
502 
503 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
504 	if (tx)
505 		reg &= ~(1 << hw_ep->epnum);
506 	else
507 		reg &= ~(1 << (hw_ep->epnum + 15));
508 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
509 
510 	/* REVISIT: Why does dmareq5 not work? */
511 	if (hw_ep->epnum == 0) {
512 		dev_dbg(musb->controller, "Not allowing DMA for ep0 %s\n", tx ? "tx" : "rx");
513 		return NULL;
514 	}
515 
516 	for (i = 0; i < MAX_DMAREQ; i++) {
517 		struct dma_channel *ch = dma_channel_pool[i];
518 		if (ch->status == MUSB_DMA_STATUS_UNKNOWN) {
519 			ch->status = MUSB_DMA_STATUS_FREE;
520 			channel = ch;
521 			chdat = ch->private_data;
522 			break;
523 		}
524 	}
525 
526 	if (!channel)
527 		return NULL;
528 
529 	if (tx) {
530 		chdat->tx = 1;
531 		dev_name = "TUSB transmit";
532 	} else {
533 		chdat->tx = 0;
534 		dev_name = "TUSB receive";
535 	}
536 
537 	chdat->musb = tusb_dma->musb;
538 	chdat->tbase = tusb_dma->tbase;
539 	chdat->hw_ep = hw_ep;
540 	chdat->epnum = hw_ep->epnum;
541 	chdat->dmareq = -1;
542 	chdat->completed_len = 0;
543 	chdat->tusb_dma = tusb_dma;
544 
545 	channel->max_len = 0x7fffffff;
546 	channel->desired_mode = 0;
547 	channel->actual_len = 0;
548 
549 	if (tusb_dma->multichannel) {
550 		ret = tusb_omap_dma_allocate_dmareq(chdat);
551 		if (ret != 0)
552 			goto free_dmareq;
553 
554 		ret = omap_request_dma(chdat->sync_dev, dev_name,
555 				tusb_omap_dma_cb, channel, &chdat->ch);
556 		if (ret != 0)
557 			goto free_dmareq;
558 	} else if (tusb_dma->ch == -1) {
559 		tusb_dma->dmareq = 0;
560 		tusb_dma->sync_dev = OMAP24XX_DMA_EXT_DMAREQ0;
561 
562 		/* Callback data gets set later in the shared dmareq case */
563 		ret = omap_request_dma(tusb_dma->sync_dev, "TUSB shared",
564 				tusb_omap_dma_cb, NULL, &tusb_dma->ch);
565 		if (ret != 0)
566 			goto free_dmareq;
567 
568 		chdat->dmareq = -1;
569 		chdat->ch = -1;
570 	}
571 
572 	dev_dbg(musb->controller, "ep%i %s dma: %s dma%i dmareq%i sync%i\n",
573 		chdat->epnum,
574 		chdat->tx ? "tx" : "rx",
575 		chdat->ch >= 0 ? "dedicated" : "shared",
576 		chdat->ch >= 0 ? chdat->ch : tusb_dma->ch,
577 		chdat->dmareq >= 0 ? chdat->dmareq : tusb_dma->dmareq,
578 		chdat->sync_dev >= 0 ? chdat->sync_dev : tusb_dma->sync_dev);
579 
580 	return channel;
581 
582 free_dmareq:
583 	tusb_omap_dma_free_dmareq(chdat);
584 
585 	dev_dbg(musb->controller, "ep%i: Could not get a DMA channel\n", chdat->epnum);
586 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
587 
588 	return NULL;
589 }
590 
591 static void tusb_omap_dma_release(struct dma_channel *channel)
592 {
593 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
594 	struct musb		*musb = chdat->musb;
595 	void __iomem		*tbase = musb->ctrl_base;
596 	u32			reg;
597 
598 	dev_dbg(musb->controller, "ep%i ch%i\n", chdat->epnum, chdat->ch);
599 
600 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
601 	if (chdat->tx)
602 		reg |= (1 << chdat->epnum);
603 	else
604 		reg |= (1 << (chdat->epnum + 15));
605 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
606 
607 	reg = musb_readl(tbase, TUSB_DMA_INT_CLEAR);
608 	if (chdat->tx)
609 		reg |= (1 << chdat->epnum);
610 	else
611 		reg |= (1 << (chdat->epnum + 15));
612 	musb_writel(tbase, TUSB_DMA_INT_CLEAR, reg);
613 
614 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
615 
616 	if (chdat->ch >= 0) {
617 		omap_stop_dma(chdat->ch);
618 		omap_free_dma(chdat->ch);
619 		chdat->ch = -1;
620 	}
621 
622 	if (chdat->dmareq >= 0)
623 		tusb_omap_dma_free_dmareq(chdat);
624 
625 	channel = NULL;
626 }
627 
628 void dma_controller_destroy(struct dma_controller *c)
629 {
630 	struct tusb_omap_dma	*tusb_dma;
631 	int			i;
632 
633 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
634 	for (i = 0; i < MAX_DMAREQ; i++) {
635 		struct dma_channel *ch = dma_channel_pool[i];
636 		if (ch) {
637 			kfree(ch->private_data);
638 			kfree(ch);
639 		}
640 	}
641 
642 	if (tusb_dma && !tusb_dma->multichannel && tusb_dma->ch >= 0)
643 		omap_free_dma(tusb_dma->ch);
644 
645 	kfree(tusb_dma);
646 }
647 
648 struct dma_controller *dma_controller_create(struct musb *musb, void __iomem *base)
649 {
650 	void __iomem		*tbase = musb->ctrl_base;
651 	struct tusb_omap_dma	*tusb_dma;
652 	int			i;
653 
654 	/* REVISIT: Get dmareq lines used from board-*.c */
655 
656 	musb_writel(musb->ctrl_base, TUSB_DMA_INT_MASK, 0x7fffffff);
657 	musb_writel(musb->ctrl_base, TUSB_DMA_EP_MAP, 0);
658 
659 	musb_writel(tbase, TUSB_DMA_REQ_CONF,
660 		TUSB_DMA_REQ_CONF_BURST_SIZE(2)
661 		| TUSB_DMA_REQ_CONF_DMA_REQ_EN(0x3f)
662 		| TUSB_DMA_REQ_CONF_DMA_REQ_ASSER(2));
663 
664 	tusb_dma = kzalloc(sizeof(struct tusb_omap_dma), GFP_KERNEL);
665 	if (!tusb_dma)
666 		goto out;
667 
668 	tusb_dma->musb = musb;
669 	tusb_dma->tbase = musb->ctrl_base;
670 
671 	tusb_dma->ch = -1;
672 	tusb_dma->dmareq = -1;
673 	tusb_dma->sync_dev = -1;
674 
675 	tusb_dma->controller.channel_alloc = tusb_omap_dma_allocate;
676 	tusb_dma->controller.channel_release = tusb_omap_dma_release;
677 	tusb_dma->controller.channel_program = tusb_omap_dma_program;
678 	tusb_dma->controller.channel_abort = tusb_omap_dma_abort;
679 
680 	if (tusb_get_revision(musb) >= TUSB_REV_30)
681 		tusb_dma->multichannel = 1;
682 
683 	for (i = 0; i < MAX_DMAREQ; i++) {
684 		struct dma_channel	*ch;
685 		struct tusb_omap_dma_ch	*chdat;
686 
687 		ch = kzalloc(sizeof(struct dma_channel), GFP_KERNEL);
688 		if (!ch)
689 			goto cleanup;
690 
691 		dma_channel_pool[i] = ch;
692 
693 		chdat = kzalloc(sizeof(struct tusb_omap_dma_ch), GFP_KERNEL);
694 		if (!chdat)
695 			goto cleanup;
696 
697 		ch->status = MUSB_DMA_STATUS_UNKNOWN;
698 		ch->private_data = chdat;
699 	}
700 
701 	return &tusb_dma->controller;
702 
703 cleanup:
704 	dma_controller_destroy(&tusb_dma->controller);
705 out:
706 	return NULL;
707 }
708