xref: /openbmc/linux/drivers/usb/musb/tusb6010_omap.c (revision cd5d5810)
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/init.h>
15 #include <linux/usb.h>
16 #include <linux/platform_device.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/slab.h>
19 #include <linux/omap-dma.h>
20 
21 #include "musb_core.h"
22 #include "tusb6010.h"
23 
24 #define to_chdat(c)		((struct tusb_omap_dma_ch *)(c)->private_data)
25 
26 #define MAX_DMAREQ		5	/* REVISIT: Really 6, but req5 not OK */
27 
28 #define OMAP24XX_DMA_EXT_DMAREQ0	2
29 #define OMAP24XX_DMA_EXT_DMAREQ1	3
30 #define OMAP242X_DMA_EXT_DMAREQ2	14
31 #define OMAP242X_DMA_EXT_DMAREQ3	15
32 #define OMAP242X_DMA_EXT_DMAREQ4	16
33 #define OMAP242X_DMA_EXT_DMAREQ5	64
34 
35 struct tusb_omap_dma_ch {
36 	struct musb		*musb;
37 	void __iomem		*tbase;
38 	unsigned long		phys_offset;
39 	int			epnum;
40 	u8			tx;
41 	struct musb_hw_ep	*hw_ep;
42 
43 	int			ch;
44 	s8			dmareq;
45 	s8			sync_dev;
46 
47 	struct tusb_omap_dma	*tusb_dma;
48 
49 	dma_addr_t		dma_addr;
50 
51 	u32			len;
52 	u16			packet_sz;
53 	u16			transfer_packet_sz;
54 	u32			transfer_len;
55 	u32			completed_len;
56 };
57 
58 struct tusb_omap_dma {
59 	struct dma_controller		controller;
60 	struct musb			*musb;
61 	void __iomem			*tbase;
62 
63 	int				ch;
64 	s8				dmareq;
65 	s8				sync_dev;
66 	unsigned			multichannel:1;
67 };
68 
69 /*
70  * Allocate dmareq0 to the current channel unless it's already taken
71  */
72 static inline int tusb_omap_use_shared_dmareq(struct tusb_omap_dma_ch *chdat)
73 {
74 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
75 
76 	if (reg != 0) {
77 		dev_dbg(chdat->musb->controller, "ep%i dmareq0 is busy for ep%i\n",
78 			chdat->epnum, reg & 0xf);
79 		return -EAGAIN;
80 	}
81 
82 	if (chdat->tx)
83 		reg = (1 << 4) | chdat->epnum;
84 	else
85 		reg = chdat->epnum;
86 
87 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
88 
89 	return 0;
90 }
91 
92 static inline void tusb_omap_free_shared_dmareq(struct tusb_omap_dma_ch *chdat)
93 {
94 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
95 
96 	if ((reg & 0xf) != chdat->epnum) {
97 		printk(KERN_ERR "ep%i trying to release dmareq0 for ep%i\n",
98 			chdat->epnum, reg & 0xf);
99 		return;
100 	}
101 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, 0);
102 }
103 
104 /*
105  * See also musb_dma_completion in plat_uds.c and musb_g_[tx|rx]() in
106  * musb_gadget.c.
107  */
108 static void tusb_omap_dma_cb(int lch, u16 ch_status, void *data)
109 {
110 	struct dma_channel	*channel = (struct dma_channel *)data;
111 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
112 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
113 	struct musb		*musb = chdat->musb;
114 	struct device		*dev = musb->controller;
115 	struct musb_hw_ep	*hw_ep = chdat->hw_ep;
116 	void __iomem		*ep_conf = hw_ep->conf;
117 	void __iomem		*mbase = musb->mregs;
118 	unsigned long		remaining, flags, pio;
119 	int			ch;
120 
121 	spin_lock_irqsave(&musb->lock, flags);
122 
123 	if (tusb_dma->multichannel)
124 		ch = chdat->ch;
125 	else
126 		ch = tusb_dma->ch;
127 
128 	if (ch_status != OMAP_DMA_BLOCK_IRQ)
129 		printk(KERN_ERR "TUSB DMA error status: %i\n", ch_status);
130 
131 	dev_dbg(musb->controller, "ep%i %s dma callback ch: %i status: %x\n",
132 		chdat->epnum, chdat->tx ? "tx" : "rx",
133 		ch, ch_status);
134 
135 	if (chdat->tx)
136 		remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
137 	else
138 		remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
139 
140 	remaining = TUSB_EP_CONFIG_XFR_SIZE(remaining);
141 
142 	/* HW issue #10: XFR_SIZE may get corrupt on DMA (both async & sync) */
143 	if (unlikely(remaining > chdat->transfer_len)) {
144 		dev_dbg(musb->controller, "Corrupt %s dma ch%i XFR_SIZE: 0x%08lx\n",
145 			chdat->tx ? "tx" : "rx", chdat->ch,
146 			remaining);
147 		remaining = 0;
148 	}
149 
150 	channel->actual_len = chdat->transfer_len - remaining;
151 	pio = chdat->len - channel->actual_len;
152 
153 	dev_dbg(musb->controller, "DMA remaining %lu/%u\n", remaining, chdat->transfer_len);
154 
155 	/* Transfer remaining 1 - 31 bytes */
156 	if (pio > 0 && pio < 32) {
157 		u8	*buf;
158 
159 		dev_dbg(musb->controller, "Using PIO for remaining %lu bytes\n", pio);
160 		buf = phys_to_virt((u32)chdat->dma_addr) + chdat->transfer_len;
161 		if (chdat->tx) {
162 			dma_unmap_single(dev, chdat->dma_addr,
163 						chdat->transfer_len,
164 						DMA_TO_DEVICE);
165 			musb_write_fifo(hw_ep, pio, buf);
166 		} else {
167 			dma_unmap_single(dev, chdat->dma_addr,
168 						chdat->transfer_len,
169 						DMA_FROM_DEVICE);
170 			musb_read_fifo(hw_ep, pio, buf);
171 		}
172 		channel->actual_len += pio;
173 	}
174 
175 	if (!tusb_dma->multichannel)
176 		tusb_omap_free_shared_dmareq(chdat);
177 
178 	channel->status = MUSB_DMA_STATUS_FREE;
179 
180 	/* Handle only RX callbacks here. TX callbacks must be handled based
181 	 * on the TUSB DMA status interrupt.
182 	 * REVISIT: Use both TUSB DMA status interrupt and OMAP DMA callback
183 	 * interrupt for RX and TX.
184 	 */
185 	if (!chdat->tx)
186 		musb_dma_completion(musb, chdat->epnum, chdat->tx);
187 
188 	/* We must terminate short tx transfers manually by setting TXPKTRDY.
189 	 * REVISIT: This same problem may occur with other MUSB dma as well.
190 	 * Easy to test with g_ether by pinging the MUSB board with ping -s54.
191 	 */
192 	if ((chdat->transfer_len < chdat->packet_sz)
193 			|| (chdat->transfer_len % chdat->packet_sz != 0)) {
194 		u16	csr;
195 
196 		if (chdat->tx) {
197 			dev_dbg(musb->controller, "terminating short tx packet\n");
198 			musb_ep_select(mbase, chdat->epnum);
199 			csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
200 			csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY
201 				| MUSB_TXCSR_P_WZC_BITS;
202 			musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
203 		}
204 	}
205 
206 	spin_unlock_irqrestore(&musb->lock, flags);
207 }
208 
209 static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
210 				u8 rndis_mode, dma_addr_t dma_addr, u32 len)
211 {
212 	struct tusb_omap_dma_ch		*chdat = to_chdat(channel);
213 	struct tusb_omap_dma		*tusb_dma = chdat->tusb_dma;
214 	struct musb			*musb = chdat->musb;
215 	struct device			*dev = musb->controller;
216 	struct musb_hw_ep		*hw_ep = chdat->hw_ep;
217 	void __iomem			*mbase = musb->mregs;
218 	void __iomem			*ep_conf = hw_ep->conf;
219 	dma_addr_t			fifo = hw_ep->fifo_sync;
220 	struct omap_dma_channel_params	dma_params;
221 	u32				dma_remaining;
222 	int				src_burst, dst_burst;
223 	u16				csr;
224 	int				ch;
225 	s8				dmareq;
226 	s8				sync_dev;
227 
228 	if (unlikely(dma_addr & 0x1) || (len < 32) || (len > packet_sz))
229 		return false;
230 
231 	/*
232 	 * HW issue #10: Async dma will eventually corrupt the XFR_SIZE
233 	 * register which will cause missed DMA interrupt. We could try to
234 	 * use a timer for the callback, but it is unsafe as the XFR_SIZE
235 	 * register is corrupt, and we won't know if the DMA worked.
236 	 */
237 	if (dma_addr & 0x2)
238 		return false;
239 
240 	/*
241 	 * Because of HW issue #10, it seems like mixing sync DMA and async
242 	 * PIO access can confuse the DMA. Make sure XFR_SIZE is reset before
243 	 * using the channel for DMA.
244 	 */
245 	if (chdat->tx)
246 		dma_remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
247 	else
248 		dma_remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
249 
250 	dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
251 	if (dma_remaining) {
252 		dev_dbg(musb->controller, "Busy %s dma ch%i, not using: %08x\n",
253 			chdat->tx ? "tx" : "rx", chdat->ch,
254 			dma_remaining);
255 		return false;
256 	}
257 
258 	chdat->transfer_len = len & ~0x1f;
259 
260 	if (len < packet_sz)
261 		chdat->transfer_packet_sz = chdat->transfer_len;
262 	else
263 		chdat->transfer_packet_sz = packet_sz;
264 
265 	if (tusb_dma->multichannel) {
266 		ch = chdat->ch;
267 		dmareq = chdat->dmareq;
268 		sync_dev = chdat->sync_dev;
269 	} else {
270 		if (tusb_omap_use_shared_dmareq(chdat) != 0) {
271 			dev_dbg(musb->controller, "could not get dma for ep%i\n", chdat->epnum);
272 			return false;
273 		}
274 		if (tusb_dma->ch < 0) {
275 			/* REVISIT: This should get blocked earlier, happens
276 			 * with MSC ErrorRecoveryTest
277 			 */
278 			WARN_ON(1);
279 			return false;
280 		}
281 
282 		ch = tusb_dma->ch;
283 		dmareq = tusb_dma->dmareq;
284 		sync_dev = tusb_dma->sync_dev;
285 		omap_set_dma_callback(ch, tusb_omap_dma_cb, channel);
286 	}
287 
288 	chdat->packet_sz = packet_sz;
289 	chdat->len = len;
290 	channel->actual_len = 0;
291 	chdat->dma_addr = dma_addr;
292 	channel->status = MUSB_DMA_STATUS_BUSY;
293 
294 	/* Since we're recycling dma areas, we need to clean or invalidate */
295 	if (chdat->tx)
296 		dma_map_single(dev, phys_to_virt(dma_addr), len,
297 				DMA_TO_DEVICE);
298 	else
299 		dma_map_single(dev, phys_to_virt(dma_addr), len,
300 				DMA_FROM_DEVICE);
301 
302 	/* Use 16-bit transfer if dma_addr is not 32-bit aligned */
303 	if ((dma_addr & 0x3) == 0) {
304 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S32;
305 		dma_params.elem_count = 8;		/* Elements in frame */
306 	} else {
307 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
308 		dma_params.elem_count = 16;		/* Elements in frame */
309 		fifo = hw_ep->fifo_async;
310 	}
311 
312 	dma_params.frame_count	= chdat->transfer_len / 32; /* Burst sz frame */
313 
314 	dev_dbg(musb->controller, "ep%i %s dma ch%i dma: %08x len: %u(%u) packet_sz: %i(%i)\n",
315 		chdat->epnum, chdat->tx ? "tx" : "rx",
316 		ch, dma_addr, chdat->transfer_len, len,
317 		chdat->transfer_packet_sz, packet_sz);
318 
319 	/*
320 	 * Prepare omap DMA for transfer
321 	 */
322 	if (chdat->tx) {
323 		dma_params.src_amode	= OMAP_DMA_AMODE_POST_INC;
324 		dma_params.src_start	= (unsigned long)dma_addr;
325 		dma_params.src_ei	= 0;
326 		dma_params.src_fi	= 0;
327 
328 		dma_params.dst_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
329 		dma_params.dst_start	= (unsigned long)fifo;
330 		dma_params.dst_ei	= 1;
331 		dma_params.dst_fi	= -31;	/* Loop 32 byte window */
332 
333 		dma_params.trigger	= sync_dev;
334 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
335 		dma_params.src_or_dst_synch	= 0;	/* Dest sync */
336 
337 		src_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 read */
338 		dst_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 write */
339 	} else {
340 		dma_params.src_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
341 		dma_params.src_start	= (unsigned long)fifo;
342 		dma_params.src_ei	= 1;
343 		dma_params.src_fi	= -31;	/* Loop 32 byte window */
344 
345 		dma_params.dst_amode	= OMAP_DMA_AMODE_POST_INC;
346 		dma_params.dst_start	= (unsigned long)dma_addr;
347 		dma_params.dst_ei	= 0;
348 		dma_params.dst_fi	= 0;
349 
350 		dma_params.trigger	= sync_dev;
351 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
352 		dma_params.src_or_dst_synch	= 1;	/* Source sync */
353 
354 		src_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 read */
355 		dst_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 write */
356 	}
357 
358 	dev_dbg(musb->controller, "ep%i %s using %i-bit %s dma from 0x%08lx to 0x%08lx\n",
359 		chdat->epnum, chdat->tx ? "tx" : "rx",
360 		(dma_params.data_type == OMAP_DMA_DATA_TYPE_S32) ? 32 : 16,
361 		((dma_addr & 0x3) == 0) ? "sync" : "async",
362 		dma_params.src_start, dma_params.dst_start);
363 
364 	omap_set_dma_params(ch, &dma_params);
365 	omap_set_dma_src_burst_mode(ch, src_burst);
366 	omap_set_dma_dest_burst_mode(ch, dst_burst);
367 	omap_set_dma_write_mode(ch, OMAP_DMA_WRITE_LAST_NON_POSTED);
368 
369 	/*
370 	 * Prepare MUSB for DMA transfer
371 	 */
372 	if (chdat->tx) {
373 		musb_ep_select(mbase, chdat->epnum);
374 		csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
375 		csr |= (MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB
376 			| MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
377 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
378 		musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
379 	} else {
380 		musb_ep_select(mbase, chdat->epnum);
381 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
382 		csr |= MUSB_RXCSR_DMAENAB;
383 		csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAMODE);
384 		musb_writew(hw_ep->regs, MUSB_RXCSR,
385 			csr | MUSB_RXCSR_P_WZC_BITS);
386 	}
387 
388 	/*
389 	 * Start DMA transfer
390 	 */
391 	omap_start_dma(ch);
392 
393 	if (chdat->tx) {
394 		/* Send transfer_packet_sz packets at a time */
395 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
396 			chdat->transfer_packet_sz);
397 
398 		musb_writel(ep_conf, TUSB_EP_TX_OFFSET,
399 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
400 	} else {
401 		/* Receive transfer_packet_sz packets at a time */
402 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
403 			chdat->transfer_packet_sz << 16);
404 
405 		musb_writel(ep_conf, TUSB_EP_RX_OFFSET,
406 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
407 	}
408 
409 	return true;
410 }
411 
412 static int tusb_omap_dma_abort(struct dma_channel *channel)
413 {
414 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
415 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
416 
417 	if (!tusb_dma->multichannel) {
418 		if (tusb_dma->ch >= 0) {
419 			omap_stop_dma(tusb_dma->ch);
420 			omap_free_dma(tusb_dma->ch);
421 			tusb_dma->ch = -1;
422 		}
423 
424 		tusb_dma->dmareq = -1;
425 		tusb_dma->sync_dev = -1;
426 	}
427 
428 	channel->status = MUSB_DMA_STATUS_FREE;
429 
430 	return 0;
431 }
432 
433 static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
434 {
435 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
436 	int		i, dmareq_nr = -1;
437 
438 	const int sync_dev[6] = {
439 		OMAP24XX_DMA_EXT_DMAREQ0,
440 		OMAP24XX_DMA_EXT_DMAREQ1,
441 		OMAP242X_DMA_EXT_DMAREQ2,
442 		OMAP242X_DMA_EXT_DMAREQ3,
443 		OMAP242X_DMA_EXT_DMAREQ4,
444 		OMAP242X_DMA_EXT_DMAREQ5,
445 	};
446 
447 	for (i = 0; i < MAX_DMAREQ; i++) {
448 		int cur = (reg & (0xf << (i * 5))) >> (i * 5);
449 		if (cur == 0) {
450 			dmareq_nr = i;
451 			break;
452 		}
453 	}
454 
455 	if (dmareq_nr == -1)
456 		return -EAGAIN;
457 
458 	reg |= (chdat->epnum << (dmareq_nr * 5));
459 	if (chdat->tx)
460 		reg |= ((1 << 4) << (dmareq_nr * 5));
461 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
462 
463 	chdat->dmareq = dmareq_nr;
464 	chdat->sync_dev = sync_dev[chdat->dmareq];
465 
466 	return 0;
467 }
468 
469 static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
470 {
471 	u32 reg;
472 
473 	if (!chdat || chdat->dmareq < 0)
474 		return;
475 
476 	reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
477 	reg &= ~(0x1f << (chdat->dmareq * 5));
478 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
479 
480 	chdat->dmareq = -1;
481 	chdat->sync_dev = -1;
482 }
483 
484 static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
485 
486 static struct dma_channel *
487 tusb_omap_dma_allocate(struct dma_controller *c,
488 		struct musb_hw_ep *hw_ep,
489 		u8 tx)
490 {
491 	int ret, i;
492 	const char		*dev_name;
493 	struct tusb_omap_dma	*tusb_dma;
494 	struct musb		*musb;
495 	void __iomem		*tbase;
496 	struct dma_channel	*channel = NULL;
497 	struct tusb_omap_dma_ch	*chdat = NULL;
498 	u32			reg;
499 
500 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
501 	musb = tusb_dma->musb;
502 	tbase = musb->ctrl_base;
503 
504 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
505 	if (tx)
506 		reg &= ~(1 << hw_ep->epnum);
507 	else
508 		reg &= ~(1 << (hw_ep->epnum + 15));
509 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
510 
511 	/* REVISIT: Why does dmareq5 not work? */
512 	if (hw_ep->epnum == 0) {
513 		dev_dbg(musb->controller, "Not allowing DMA for ep0 %s\n", tx ? "tx" : "rx");
514 		return NULL;
515 	}
516 
517 	for (i = 0; i < MAX_DMAREQ; i++) {
518 		struct dma_channel *ch = dma_channel_pool[i];
519 		if (ch->status == MUSB_DMA_STATUS_UNKNOWN) {
520 			ch->status = MUSB_DMA_STATUS_FREE;
521 			channel = ch;
522 			chdat = ch->private_data;
523 			break;
524 		}
525 	}
526 
527 	if (!channel)
528 		return NULL;
529 
530 	if (tx) {
531 		chdat->tx = 1;
532 		dev_name = "TUSB transmit";
533 	} else {
534 		chdat->tx = 0;
535 		dev_name = "TUSB receive";
536 	}
537 
538 	chdat->musb = tusb_dma->musb;
539 	chdat->tbase = tusb_dma->tbase;
540 	chdat->hw_ep = hw_ep;
541 	chdat->epnum = hw_ep->epnum;
542 	chdat->dmareq = -1;
543 	chdat->completed_len = 0;
544 	chdat->tusb_dma = tusb_dma;
545 
546 	channel->max_len = 0x7fffffff;
547 	channel->desired_mode = 0;
548 	channel->actual_len = 0;
549 
550 	if (tusb_dma->multichannel) {
551 		ret = tusb_omap_dma_allocate_dmareq(chdat);
552 		if (ret != 0)
553 			goto free_dmareq;
554 
555 		ret = omap_request_dma(chdat->sync_dev, dev_name,
556 				tusb_omap_dma_cb, channel, &chdat->ch);
557 		if (ret != 0)
558 			goto free_dmareq;
559 	} else if (tusb_dma->ch == -1) {
560 		tusb_dma->dmareq = 0;
561 		tusb_dma->sync_dev = OMAP24XX_DMA_EXT_DMAREQ0;
562 
563 		/* Callback data gets set later in the shared dmareq case */
564 		ret = omap_request_dma(tusb_dma->sync_dev, "TUSB shared",
565 				tusb_omap_dma_cb, NULL, &tusb_dma->ch);
566 		if (ret != 0)
567 			goto free_dmareq;
568 
569 		chdat->dmareq = -1;
570 		chdat->ch = -1;
571 	}
572 
573 	dev_dbg(musb->controller, "ep%i %s dma: %s dma%i dmareq%i sync%i\n",
574 		chdat->epnum,
575 		chdat->tx ? "tx" : "rx",
576 		chdat->ch >= 0 ? "dedicated" : "shared",
577 		chdat->ch >= 0 ? chdat->ch : tusb_dma->ch,
578 		chdat->dmareq >= 0 ? chdat->dmareq : tusb_dma->dmareq,
579 		chdat->sync_dev >= 0 ? chdat->sync_dev : tusb_dma->sync_dev);
580 
581 	return channel;
582 
583 free_dmareq:
584 	tusb_omap_dma_free_dmareq(chdat);
585 
586 	dev_dbg(musb->controller, "ep%i: Could not get a DMA channel\n", chdat->epnum);
587 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
588 
589 	return NULL;
590 }
591 
592 static void tusb_omap_dma_release(struct dma_channel *channel)
593 {
594 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
595 	struct musb		*musb = chdat->musb;
596 	void __iomem		*tbase = musb->ctrl_base;
597 	u32			reg;
598 
599 	dev_dbg(musb->controller, "ep%i ch%i\n", chdat->epnum, chdat->ch);
600 
601 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
602 	if (chdat->tx)
603 		reg |= (1 << chdat->epnum);
604 	else
605 		reg |= (1 << (chdat->epnum + 15));
606 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
607 
608 	reg = musb_readl(tbase, TUSB_DMA_INT_CLEAR);
609 	if (chdat->tx)
610 		reg |= (1 << chdat->epnum);
611 	else
612 		reg |= (1 << (chdat->epnum + 15));
613 	musb_writel(tbase, TUSB_DMA_INT_CLEAR, reg);
614 
615 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
616 
617 	if (chdat->ch >= 0) {
618 		omap_stop_dma(chdat->ch);
619 		omap_free_dma(chdat->ch);
620 		chdat->ch = -1;
621 	}
622 
623 	if (chdat->dmareq >= 0)
624 		tusb_omap_dma_free_dmareq(chdat);
625 
626 	channel = NULL;
627 }
628 
629 void dma_controller_destroy(struct dma_controller *c)
630 {
631 	struct tusb_omap_dma	*tusb_dma;
632 	int			i;
633 
634 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
635 	for (i = 0; i < MAX_DMAREQ; i++) {
636 		struct dma_channel *ch = dma_channel_pool[i];
637 		if (ch) {
638 			kfree(ch->private_data);
639 			kfree(ch);
640 		}
641 	}
642 
643 	if (tusb_dma && !tusb_dma->multichannel && tusb_dma->ch >= 0)
644 		omap_free_dma(tusb_dma->ch);
645 
646 	kfree(tusb_dma);
647 }
648 
649 struct dma_controller *dma_controller_create(struct musb *musb, void __iomem *base)
650 {
651 	void __iomem		*tbase = musb->ctrl_base;
652 	struct tusb_omap_dma	*tusb_dma;
653 	int			i;
654 
655 	/* REVISIT: Get dmareq lines used from board-*.c */
656 
657 	musb_writel(musb->ctrl_base, TUSB_DMA_INT_MASK, 0x7fffffff);
658 	musb_writel(musb->ctrl_base, TUSB_DMA_EP_MAP, 0);
659 
660 	musb_writel(tbase, TUSB_DMA_REQ_CONF,
661 		TUSB_DMA_REQ_CONF_BURST_SIZE(2)
662 		| TUSB_DMA_REQ_CONF_DMA_REQ_EN(0x3f)
663 		| TUSB_DMA_REQ_CONF_DMA_REQ_ASSER(2));
664 
665 	tusb_dma = kzalloc(sizeof(struct tusb_omap_dma), GFP_KERNEL);
666 	if (!tusb_dma)
667 		goto out;
668 
669 	tusb_dma->musb = musb;
670 	tusb_dma->tbase = musb->ctrl_base;
671 
672 	tusb_dma->ch = -1;
673 	tusb_dma->dmareq = -1;
674 	tusb_dma->sync_dev = -1;
675 
676 	tusb_dma->controller.channel_alloc = tusb_omap_dma_allocate;
677 	tusb_dma->controller.channel_release = tusb_omap_dma_release;
678 	tusb_dma->controller.channel_program = tusb_omap_dma_program;
679 	tusb_dma->controller.channel_abort = tusb_omap_dma_abort;
680 
681 	if (tusb_get_revision(musb) >= TUSB_REV_30)
682 		tusb_dma->multichannel = 1;
683 
684 	for (i = 0; i < MAX_DMAREQ; i++) {
685 		struct dma_channel	*ch;
686 		struct tusb_omap_dma_ch	*chdat;
687 
688 		ch = kzalloc(sizeof(struct dma_channel), GFP_KERNEL);
689 		if (!ch)
690 			goto cleanup;
691 
692 		dma_channel_pool[i] = ch;
693 
694 		chdat = kzalloc(sizeof(struct tusb_omap_dma_ch), GFP_KERNEL);
695 		if (!chdat)
696 			goto cleanup;
697 
698 		ch->status = MUSB_DMA_STATUS_UNKNOWN;
699 		ch->private_data = chdat;
700 	}
701 
702 	return &tusb_dma->controller;
703 
704 cleanup:
705 	dma_controller_destroy(&tusb_dma->controller);
706 out:
707 	return NULL;
708 }
709