xref: /linux/drivers/usb/musb/tusb6010_omap.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 static int tusb_omap_dma_start(struct dma_controller *c)
70 {
71 	struct tusb_omap_dma	*tusb_dma;
72 
73 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
74 
75 	/* dev_dbg(musb->controller, "ep%i ch: %i\n", chdat->epnum, chdat->ch); */
76 
77 	return 0;
78 }
79 
80 static int tusb_omap_dma_stop(struct dma_controller *c)
81 {
82 	struct tusb_omap_dma	*tusb_dma;
83 
84 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
85 
86 	/* dev_dbg(musb->controller, "ep%i ch: %i\n", chdat->epnum, chdat->ch); */
87 
88 	return 0;
89 }
90 
91 /*
92  * Allocate dmareq0 to the current channel unless it's already taken
93  */
94 static inline int tusb_omap_use_shared_dmareq(struct tusb_omap_dma_ch *chdat)
95 {
96 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
97 
98 	if (reg != 0) {
99 		dev_dbg(chdat->musb->controller, "ep%i dmareq0 is busy for ep%i\n",
100 			chdat->epnum, reg & 0xf);
101 		return -EAGAIN;
102 	}
103 
104 	if (chdat->tx)
105 		reg = (1 << 4) | chdat->epnum;
106 	else
107 		reg = chdat->epnum;
108 
109 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
110 
111 	return 0;
112 }
113 
114 static inline void tusb_omap_free_shared_dmareq(struct tusb_omap_dma_ch *chdat)
115 {
116 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
117 
118 	if ((reg & 0xf) != chdat->epnum) {
119 		printk(KERN_ERR "ep%i trying to release dmareq0 for ep%i\n",
120 			chdat->epnum, reg & 0xf);
121 		return;
122 	}
123 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, 0);
124 }
125 
126 /*
127  * See also musb_dma_completion in plat_uds.c and musb_g_[tx|rx]() in
128  * musb_gadget.c.
129  */
130 static void tusb_omap_dma_cb(int lch, u16 ch_status, void *data)
131 {
132 	struct dma_channel	*channel = (struct dma_channel *)data;
133 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
134 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
135 	struct musb		*musb = chdat->musb;
136 	struct device		*dev = musb->controller;
137 	struct musb_hw_ep	*hw_ep = chdat->hw_ep;
138 	void __iomem		*ep_conf = hw_ep->conf;
139 	void __iomem		*mbase = musb->mregs;
140 	unsigned long		remaining, flags, pio;
141 	int			ch;
142 
143 	spin_lock_irqsave(&musb->lock, flags);
144 
145 	if (tusb_dma->multichannel)
146 		ch = chdat->ch;
147 	else
148 		ch = tusb_dma->ch;
149 
150 	if (ch_status != OMAP_DMA_BLOCK_IRQ)
151 		printk(KERN_ERR "TUSB DMA error status: %i\n", ch_status);
152 
153 	dev_dbg(musb->controller, "ep%i %s dma callback ch: %i status: %x\n",
154 		chdat->epnum, chdat->tx ? "tx" : "rx",
155 		ch, ch_status);
156 
157 	if (chdat->tx)
158 		remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
159 	else
160 		remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
161 
162 	remaining = TUSB_EP_CONFIG_XFR_SIZE(remaining);
163 
164 	/* HW issue #10: XFR_SIZE may get corrupt on DMA (both async & sync) */
165 	if (unlikely(remaining > chdat->transfer_len)) {
166 		dev_dbg(musb->controller, "Corrupt %s dma ch%i XFR_SIZE: 0x%08lx\n",
167 			chdat->tx ? "tx" : "rx", chdat->ch,
168 			remaining);
169 		remaining = 0;
170 	}
171 
172 	channel->actual_len = chdat->transfer_len - remaining;
173 	pio = chdat->len - channel->actual_len;
174 
175 	dev_dbg(musb->controller, "DMA remaining %lu/%u\n", remaining, chdat->transfer_len);
176 
177 	/* Transfer remaining 1 - 31 bytes */
178 	if (pio > 0 && pio < 32) {
179 		u8	*buf;
180 
181 		dev_dbg(musb->controller, "Using PIO for remaining %lu bytes\n", pio);
182 		buf = phys_to_virt((u32)chdat->dma_addr) + chdat->transfer_len;
183 		if (chdat->tx) {
184 			dma_unmap_single(dev, chdat->dma_addr,
185 						chdat->transfer_len,
186 						DMA_TO_DEVICE);
187 			musb_write_fifo(hw_ep, pio, buf);
188 		} else {
189 			dma_unmap_single(dev, chdat->dma_addr,
190 						chdat->transfer_len,
191 						DMA_FROM_DEVICE);
192 			musb_read_fifo(hw_ep, pio, buf);
193 		}
194 		channel->actual_len += pio;
195 	}
196 
197 	if (!tusb_dma->multichannel)
198 		tusb_omap_free_shared_dmareq(chdat);
199 
200 	channel->status = MUSB_DMA_STATUS_FREE;
201 
202 	/* Handle only RX callbacks here. TX callbacks must be handled based
203 	 * on the TUSB DMA status interrupt.
204 	 * REVISIT: Use both TUSB DMA status interrupt and OMAP DMA callback
205 	 * interrupt for RX and TX.
206 	 */
207 	if (!chdat->tx)
208 		musb_dma_completion(musb, chdat->epnum, chdat->tx);
209 
210 	/* We must terminate short tx transfers manually by setting TXPKTRDY.
211 	 * REVISIT: This same problem may occur with other MUSB dma as well.
212 	 * Easy to test with g_ether by pinging the MUSB board with ping -s54.
213 	 */
214 	if ((chdat->transfer_len < chdat->packet_sz)
215 			|| (chdat->transfer_len % chdat->packet_sz != 0)) {
216 		u16	csr;
217 
218 		if (chdat->tx) {
219 			dev_dbg(musb->controller, "terminating short tx packet\n");
220 			musb_ep_select(mbase, chdat->epnum);
221 			csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
222 			csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY
223 				| MUSB_TXCSR_P_WZC_BITS;
224 			musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
225 		}
226 	}
227 
228 	spin_unlock_irqrestore(&musb->lock, flags);
229 }
230 
231 static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
232 				u8 rndis_mode, dma_addr_t dma_addr, u32 len)
233 {
234 	struct tusb_omap_dma_ch		*chdat = to_chdat(channel);
235 	struct tusb_omap_dma		*tusb_dma = chdat->tusb_dma;
236 	struct musb			*musb = chdat->musb;
237 	struct device			*dev = musb->controller;
238 	struct musb_hw_ep		*hw_ep = chdat->hw_ep;
239 	void __iomem			*mbase = musb->mregs;
240 	void __iomem			*ep_conf = hw_ep->conf;
241 	dma_addr_t			fifo = hw_ep->fifo_sync;
242 	struct omap_dma_channel_params	dma_params;
243 	u32				dma_remaining;
244 	int				src_burst, dst_burst;
245 	u16				csr;
246 	int				ch;
247 	s8				dmareq;
248 	s8				sync_dev;
249 
250 	if (unlikely(dma_addr & 0x1) || (len < 32) || (len > packet_sz))
251 		return false;
252 
253 	/*
254 	 * HW issue #10: Async dma will eventually corrupt the XFR_SIZE
255 	 * register which will cause missed DMA interrupt. We could try to
256 	 * use a timer for the callback, but it is unsafe as the XFR_SIZE
257 	 * register is corrupt, and we won't know if the DMA worked.
258 	 */
259 	if (dma_addr & 0x2)
260 		return false;
261 
262 	/*
263 	 * Because of HW issue #10, it seems like mixing sync DMA and async
264 	 * PIO access can confuse the DMA. Make sure XFR_SIZE is reset before
265 	 * using the channel for DMA.
266 	 */
267 	if (chdat->tx)
268 		dma_remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
269 	else
270 		dma_remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
271 
272 	dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
273 	if (dma_remaining) {
274 		dev_dbg(musb->controller, "Busy %s dma ch%i, not using: %08x\n",
275 			chdat->tx ? "tx" : "rx", chdat->ch,
276 			dma_remaining);
277 		return false;
278 	}
279 
280 	chdat->transfer_len = len & ~0x1f;
281 
282 	if (len < packet_sz)
283 		chdat->transfer_packet_sz = chdat->transfer_len;
284 	else
285 		chdat->transfer_packet_sz = packet_sz;
286 
287 	if (tusb_dma->multichannel) {
288 		ch = chdat->ch;
289 		dmareq = chdat->dmareq;
290 		sync_dev = chdat->sync_dev;
291 	} else {
292 		if (tusb_omap_use_shared_dmareq(chdat) != 0) {
293 			dev_dbg(musb->controller, "could not get dma for ep%i\n", chdat->epnum);
294 			return false;
295 		}
296 		if (tusb_dma->ch < 0) {
297 			/* REVISIT: This should get blocked earlier, happens
298 			 * with MSC ErrorRecoveryTest
299 			 */
300 			WARN_ON(1);
301 			return false;
302 		}
303 
304 		ch = tusb_dma->ch;
305 		dmareq = tusb_dma->dmareq;
306 		sync_dev = tusb_dma->sync_dev;
307 		omap_set_dma_callback(ch, tusb_omap_dma_cb, channel);
308 	}
309 
310 	chdat->packet_sz = packet_sz;
311 	chdat->len = len;
312 	channel->actual_len = 0;
313 	chdat->dma_addr = dma_addr;
314 	channel->status = MUSB_DMA_STATUS_BUSY;
315 
316 	/* Since we're recycling dma areas, we need to clean or invalidate */
317 	if (chdat->tx)
318 		dma_map_single(dev, phys_to_virt(dma_addr), len,
319 				DMA_TO_DEVICE);
320 	else
321 		dma_map_single(dev, phys_to_virt(dma_addr), len,
322 				DMA_FROM_DEVICE);
323 
324 	/* Use 16-bit transfer if dma_addr is not 32-bit aligned */
325 	if ((dma_addr & 0x3) == 0) {
326 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S32;
327 		dma_params.elem_count = 8;		/* Elements in frame */
328 	} else {
329 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
330 		dma_params.elem_count = 16;		/* Elements in frame */
331 		fifo = hw_ep->fifo_async;
332 	}
333 
334 	dma_params.frame_count	= chdat->transfer_len / 32; /* Burst sz frame */
335 
336 	dev_dbg(musb->controller, "ep%i %s dma ch%i dma: %08x len: %u(%u) packet_sz: %i(%i)\n",
337 		chdat->epnum, chdat->tx ? "tx" : "rx",
338 		ch, dma_addr, chdat->transfer_len, len,
339 		chdat->transfer_packet_sz, packet_sz);
340 
341 	/*
342 	 * Prepare omap DMA for transfer
343 	 */
344 	if (chdat->tx) {
345 		dma_params.src_amode	= OMAP_DMA_AMODE_POST_INC;
346 		dma_params.src_start	= (unsigned long)dma_addr;
347 		dma_params.src_ei	= 0;
348 		dma_params.src_fi	= 0;
349 
350 		dma_params.dst_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
351 		dma_params.dst_start	= (unsigned long)fifo;
352 		dma_params.dst_ei	= 1;
353 		dma_params.dst_fi	= -31;	/* Loop 32 byte window */
354 
355 		dma_params.trigger	= sync_dev;
356 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
357 		dma_params.src_or_dst_synch	= 0;	/* Dest sync */
358 
359 		src_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 read */
360 		dst_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 write */
361 	} else {
362 		dma_params.src_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
363 		dma_params.src_start	= (unsigned long)fifo;
364 		dma_params.src_ei	= 1;
365 		dma_params.src_fi	= -31;	/* Loop 32 byte window */
366 
367 		dma_params.dst_amode	= OMAP_DMA_AMODE_POST_INC;
368 		dma_params.dst_start	= (unsigned long)dma_addr;
369 		dma_params.dst_ei	= 0;
370 		dma_params.dst_fi	= 0;
371 
372 		dma_params.trigger	= sync_dev;
373 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
374 		dma_params.src_or_dst_synch	= 1;	/* Source sync */
375 
376 		src_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 read */
377 		dst_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 write */
378 	}
379 
380 	dev_dbg(musb->controller, "ep%i %s using %i-bit %s dma from 0x%08lx to 0x%08lx\n",
381 		chdat->epnum, chdat->tx ? "tx" : "rx",
382 		(dma_params.data_type == OMAP_DMA_DATA_TYPE_S32) ? 32 : 16,
383 		((dma_addr & 0x3) == 0) ? "sync" : "async",
384 		dma_params.src_start, dma_params.dst_start);
385 
386 	omap_set_dma_params(ch, &dma_params);
387 	omap_set_dma_src_burst_mode(ch, src_burst);
388 	omap_set_dma_dest_burst_mode(ch, dst_burst);
389 	omap_set_dma_write_mode(ch, OMAP_DMA_WRITE_LAST_NON_POSTED);
390 
391 	/*
392 	 * Prepare MUSB for DMA transfer
393 	 */
394 	if (chdat->tx) {
395 		musb_ep_select(mbase, chdat->epnum);
396 		csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
397 		csr |= (MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB
398 			| MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
399 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
400 		musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
401 	} else {
402 		musb_ep_select(mbase, chdat->epnum);
403 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
404 		csr |= MUSB_RXCSR_DMAENAB;
405 		csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAMODE);
406 		musb_writew(hw_ep->regs, MUSB_RXCSR,
407 			csr | MUSB_RXCSR_P_WZC_BITS);
408 	}
409 
410 	/*
411 	 * Start DMA transfer
412 	 */
413 	omap_start_dma(ch);
414 
415 	if (chdat->tx) {
416 		/* Send transfer_packet_sz packets at a time */
417 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
418 			chdat->transfer_packet_sz);
419 
420 		musb_writel(ep_conf, TUSB_EP_TX_OFFSET,
421 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
422 	} else {
423 		/* Receive transfer_packet_sz packets at a time */
424 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
425 			chdat->transfer_packet_sz << 16);
426 
427 		musb_writel(ep_conf, TUSB_EP_RX_OFFSET,
428 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
429 	}
430 
431 	return true;
432 }
433 
434 static int tusb_omap_dma_abort(struct dma_channel *channel)
435 {
436 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
437 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
438 
439 	if (!tusb_dma->multichannel) {
440 		if (tusb_dma->ch >= 0) {
441 			omap_stop_dma(tusb_dma->ch);
442 			omap_free_dma(tusb_dma->ch);
443 			tusb_dma->ch = -1;
444 		}
445 
446 		tusb_dma->dmareq = -1;
447 		tusb_dma->sync_dev = -1;
448 	}
449 
450 	channel->status = MUSB_DMA_STATUS_FREE;
451 
452 	return 0;
453 }
454 
455 static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
456 {
457 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
458 	int		i, dmareq_nr = -1;
459 
460 	const int sync_dev[6] = {
461 		OMAP24XX_DMA_EXT_DMAREQ0,
462 		OMAP24XX_DMA_EXT_DMAREQ1,
463 		OMAP242X_DMA_EXT_DMAREQ2,
464 		OMAP242X_DMA_EXT_DMAREQ3,
465 		OMAP242X_DMA_EXT_DMAREQ4,
466 		OMAP242X_DMA_EXT_DMAREQ5,
467 	};
468 
469 	for (i = 0; i < MAX_DMAREQ; i++) {
470 		int cur = (reg & (0xf << (i * 5))) >> (i * 5);
471 		if (cur == 0) {
472 			dmareq_nr = i;
473 			break;
474 		}
475 	}
476 
477 	if (dmareq_nr == -1)
478 		return -EAGAIN;
479 
480 	reg |= (chdat->epnum << (dmareq_nr * 5));
481 	if (chdat->tx)
482 		reg |= ((1 << 4) << (dmareq_nr * 5));
483 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
484 
485 	chdat->dmareq = dmareq_nr;
486 	chdat->sync_dev = sync_dev[chdat->dmareq];
487 
488 	return 0;
489 }
490 
491 static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
492 {
493 	u32 reg;
494 
495 	if (!chdat || chdat->dmareq < 0)
496 		return;
497 
498 	reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
499 	reg &= ~(0x1f << (chdat->dmareq * 5));
500 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
501 
502 	chdat->dmareq = -1;
503 	chdat->sync_dev = -1;
504 }
505 
506 static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
507 
508 static struct dma_channel *
509 tusb_omap_dma_allocate(struct dma_controller *c,
510 		struct musb_hw_ep *hw_ep,
511 		u8 tx)
512 {
513 	int ret, i;
514 	const char		*dev_name;
515 	struct tusb_omap_dma	*tusb_dma;
516 	struct musb		*musb;
517 	void __iomem		*tbase;
518 	struct dma_channel	*channel = NULL;
519 	struct tusb_omap_dma_ch	*chdat = NULL;
520 	u32			reg;
521 
522 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
523 	musb = tusb_dma->musb;
524 	tbase = musb->ctrl_base;
525 
526 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
527 	if (tx)
528 		reg &= ~(1 << hw_ep->epnum);
529 	else
530 		reg &= ~(1 << (hw_ep->epnum + 15));
531 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
532 
533 	/* REVISIT: Why does dmareq5 not work? */
534 	if (hw_ep->epnum == 0) {
535 		dev_dbg(musb->controller, "Not allowing DMA for ep0 %s\n", tx ? "tx" : "rx");
536 		return NULL;
537 	}
538 
539 	for (i = 0; i < MAX_DMAREQ; i++) {
540 		struct dma_channel *ch = dma_channel_pool[i];
541 		if (ch->status == MUSB_DMA_STATUS_UNKNOWN) {
542 			ch->status = MUSB_DMA_STATUS_FREE;
543 			channel = ch;
544 			chdat = ch->private_data;
545 			break;
546 		}
547 	}
548 
549 	if (!channel)
550 		return NULL;
551 
552 	if (tx) {
553 		chdat->tx = 1;
554 		dev_name = "TUSB transmit";
555 	} else {
556 		chdat->tx = 0;
557 		dev_name = "TUSB receive";
558 	}
559 
560 	chdat->musb = tusb_dma->musb;
561 	chdat->tbase = tusb_dma->tbase;
562 	chdat->hw_ep = hw_ep;
563 	chdat->epnum = hw_ep->epnum;
564 	chdat->dmareq = -1;
565 	chdat->completed_len = 0;
566 	chdat->tusb_dma = tusb_dma;
567 
568 	channel->max_len = 0x7fffffff;
569 	channel->desired_mode = 0;
570 	channel->actual_len = 0;
571 
572 	if (tusb_dma->multichannel) {
573 		ret = tusb_omap_dma_allocate_dmareq(chdat);
574 		if (ret != 0)
575 			goto free_dmareq;
576 
577 		ret = omap_request_dma(chdat->sync_dev, dev_name,
578 				tusb_omap_dma_cb, channel, &chdat->ch);
579 		if (ret != 0)
580 			goto free_dmareq;
581 	} else if (tusb_dma->ch == -1) {
582 		tusb_dma->dmareq = 0;
583 		tusb_dma->sync_dev = OMAP24XX_DMA_EXT_DMAREQ0;
584 
585 		/* Callback data gets set later in the shared dmareq case */
586 		ret = omap_request_dma(tusb_dma->sync_dev, "TUSB shared",
587 				tusb_omap_dma_cb, NULL, &tusb_dma->ch);
588 		if (ret != 0)
589 			goto free_dmareq;
590 
591 		chdat->dmareq = -1;
592 		chdat->ch = -1;
593 	}
594 
595 	dev_dbg(musb->controller, "ep%i %s dma: %s dma%i dmareq%i sync%i\n",
596 		chdat->epnum,
597 		chdat->tx ? "tx" : "rx",
598 		chdat->ch >= 0 ? "dedicated" : "shared",
599 		chdat->ch >= 0 ? chdat->ch : tusb_dma->ch,
600 		chdat->dmareq >= 0 ? chdat->dmareq : tusb_dma->dmareq,
601 		chdat->sync_dev >= 0 ? chdat->sync_dev : tusb_dma->sync_dev);
602 
603 	return channel;
604 
605 free_dmareq:
606 	tusb_omap_dma_free_dmareq(chdat);
607 
608 	dev_dbg(musb->controller, "ep%i: Could not get a DMA channel\n", chdat->epnum);
609 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
610 
611 	return NULL;
612 }
613 
614 static void tusb_omap_dma_release(struct dma_channel *channel)
615 {
616 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
617 	struct musb		*musb = chdat->musb;
618 	void __iomem		*tbase = musb->ctrl_base;
619 	u32			reg;
620 
621 	dev_dbg(musb->controller, "ep%i ch%i\n", chdat->epnum, chdat->ch);
622 
623 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
624 	if (chdat->tx)
625 		reg |= (1 << chdat->epnum);
626 	else
627 		reg |= (1 << (chdat->epnum + 15));
628 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
629 
630 	reg = musb_readl(tbase, TUSB_DMA_INT_CLEAR);
631 	if (chdat->tx)
632 		reg |= (1 << chdat->epnum);
633 	else
634 		reg |= (1 << (chdat->epnum + 15));
635 	musb_writel(tbase, TUSB_DMA_INT_CLEAR, reg);
636 
637 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
638 
639 	if (chdat->ch >= 0) {
640 		omap_stop_dma(chdat->ch);
641 		omap_free_dma(chdat->ch);
642 		chdat->ch = -1;
643 	}
644 
645 	if (chdat->dmareq >= 0)
646 		tusb_omap_dma_free_dmareq(chdat);
647 
648 	channel = NULL;
649 }
650 
651 void dma_controller_destroy(struct dma_controller *c)
652 {
653 	struct tusb_omap_dma	*tusb_dma;
654 	int			i;
655 
656 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
657 	for (i = 0; i < MAX_DMAREQ; i++) {
658 		struct dma_channel *ch = dma_channel_pool[i];
659 		if (ch) {
660 			kfree(ch->private_data);
661 			kfree(ch);
662 		}
663 	}
664 
665 	if (tusb_dma && !tusb_dma->multichannel && tusb_dma->ch >= 0)
666 		omap_free_dma(tusb_dma->ch);
667 
668 	kfree(tusb_dma);
669 }
670 
671 struct dma_controller *dma_controller_create(struct musb *musb, void __iomem *base)
672 {
673 	void __iomem		*tbase = musb->ctrl_base;
674 	struct tusb_omap_dma	*tusb_dma;
675 	int			i;
676 
677 	/* REVISIT: Get dmareq lines used from board-*.c */
678 
679 	musb_writel(musb->ctrl_base, TUSB_DMA_INT_MASK, 0x7fffffff);
680 	musb_writel(musb->ctrl_base, TUSB_DMA_EP_MAP, 0);
681 
682 	musb_writel(tbase, TUSB_DMA_REQ_CONF,
683 		TUSB_DMA_REQ_CONF_BURST_SIZE(2)
684 		| TUSB_DMA_REQ_CONF_DMA_REQ_EN(0x3f)
685 		| TUSB_DMA_REQ_CONF_DMA_REQ_ASSER(2));
686 
687 	tusb_dma = kzalloc(sizeof(struct tusb_omap_dma), GFP_KERNEL);
688 	if (!tusb_dma)
689 		goto out;
690 
691 	tusb_dma->musb = musb;
692 	tusb_dma->tbase = musb->ctrl_base;
693 
694 	tusb_dma->ch = -1;
695 	tusb_dma->dmareq = -1;
696 	tusb_dma->sync_dev = -1;
697 
698 	tusb_dma->controller.start = tusb_omap_dma_start;
699 	tusb_dma->controller.stop = tusb_omap_dma_stop;
700 	tusb_dma->controller.channel_alloc = tusb_omap_dma_allocate;
701 	tusb_dma->controller.channel_release = tusb_omap_dma_release;
702 	tusb_dma->controller.channel_program = tusb_omap_dma_program;
703 	tusb_dma->controller.channel_abort = tusb_omap_dma_abort;
704 
705 	if (tusb_get_revision(musb) >= TUSB_REV_30)
706 		tusb_dma->multichannel = 1;
707 
708 	for (i = 0; i < MAX_DMAREQ; i++) {
709 		struct dma_channel	*ch;
710 		struct tusb_omap_dma_ch	*chdat;
711 
712 		ch = kzalloc(sizeof(struct dma_channel), GFP_KERNEL);
713 		if (!ch)
714 			goto cleanup;
715 
716 		dma_channel_pool[i] = ch;
717 
718 		chdat = kzalloc(sizeof(struct tusb_omap_dma_ch), GFP_KERNEL);
719 		if (!chdat)
720 			goto cleanup;
721 
722 		ch->status = MUSB_DMA_STATUS_UNKNOWN;
723 		ch->private_data = chdat;
724 	}
725 
726 	return &tusb_dma->controller;
727 
728 cleanup:
729 	dma_controller_destroy(&tusb_dma->controller);
730 out:
731 	return NULL;
732 }
733