xref: /openbmc/linux/drivers/usb/musb/tusb6010_omap.c (revision 4e1a33b1)
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 	void __iomem			*tbase;
60 
61 	int				ch;
62 	s8				dmareq;
63 	s8				sync_dev;
64 	unsigned			multichannel:1;
65 };
66 
67 /*
68  * Allocate dmareq0 to the current channel unless it's already taken
69  */
70 static inline int tusb_omap_use_shared_dmareq(struct tusb_omap_dma_ch *chdat)
71 {
72 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
73 
74 	if (reg != 0) {
75 		dev_dbg(chdat->musb->controller, "ep%i dmareq0 is busy for ep%i\n",
76 			chdat->epnum, reg & 0xf);
77 		return -EAGAIN;
78 	}
79 
80 	if (chdat->tx)
81 		reg = (1 << 4) | chdat->epnum;
82 	else
83 		reg = chdat->epnum;
84 
85 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
86 
87 	return 0;
88 }
89 
90 static inline void tusb_omap_free_shared_dmareq(struct tusb_omap_dma_ch *chdat)
91 {
92 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
93 
94 	if ((reg & 0xf) != chdat->epnum) {
95 		printk(KERN_ERR "ep%i trying to release dmareq0 for ep%i\n",
96 			chdat->epnum, reg & 0xf);
97 		return;
98 	}
99 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, 0);
100 }
101 
102 /*
103  * See also musb_dma_completion in plat_uds.c and musb_g_[tx|rx]() in
104  * musb_gadget.c.
105  */
106 static void tusb_omap_dma_cb(int lch, u16 ch_status, void *data)
107 {
108 	struct dma_channel	*channel = (struct dma_channel *)data;
109 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
110 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
111 	struct musb		*musb = chdat->musb;
112 	struct device		*dev = musb->controller;
113 	struct musb_hw_ep	*hw_ep = chdat->hw_ep;
114 	void __iomem		*ep_conf = hw_ep->conf;
115 	void __iomem		*mbase = musb->mregs;
116 	unsigned long		remaining, flags, pio;
117 	int			ch;
118 
119 	spin_lock_irqsave(&musb->lock, flags);
120 
121 	if (tusb_dma->multichannel)
122 		ch = chdat->ch;
123 	else
124 		ch = tusb_dma->ch;
125 
126 	if (ch_status != OMAP_DMA_BLOCK_IRQ)
127 		printk(KERN_ERR "TUSB DMA error status: %i\n", ch_status);
128 
129 	dev_dbg(musb->controller, "ep%i %s dma callback ch: %i status: %x\n",
130 		chdat->epnum, chdat->tx ? "tx" : "rx",
131 		ch, ch_status);
132 
133 	if (chdat->tx)
134 		remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
135 	else
136 		remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
137 
138 	remaining = TUSB_EP_CONFIG_XFR_SIZE(remaining);
139 
140 	/* HW issue #10: XFR_SIZE may get corrupt on DMA (both async & sync) */
141 	if (unlikely(remaining > chdat->transfer_len)) {
142 		dev_dbg(musb->controller, "Corrupt %s dma ch%i XFR_SIZE: 0x%08lx\n",
143 			chdat->tx ? "tx" : "rx", chdat->ch,
144 			remaining);
145 		remaining = 0;
146 	}
147 
148 	channel->actual_len = chdat->transfer_len - remaining;
149 	pio = chdat->len - channel->actual_len;
150 
151 	dev_dbg(musb->controller, "DMA remaining %lu/%u\n", remaining, chdat->transfer_len);
152 
153 	/* Transfer remaining 1 - 31 bytes */
154 	if (pio > 0 && pio < 32) {
155 		u8	*buf;
156 
157 		dev_dbg(musb->controller, "Using PIO for remaining %lu bytes\n", pio);
158 		buf = phys_to_virt((u32)chdat->dma_addr) + chdat->transfer_len;
159 		if (chdat->tx) {
160 			dma_unmap_single(dev, chdat->dma_addr,
161 						chdat->transfer_len,
162 						DMA_TO_DEVICE);
163 			musb_write_fifo(hw_ep, pio, buf);
164 		} else {
165 			dma_unmap_single(dev, chdat->dma_addr,
166 						chdat->transfer_len,
167 						DMA_FROM_DEVICE);
168 			musb_read_fifo(hw_ep, pio, buf);
169 		}
170 		channel->actual_len += pio;
171 	}
172 
173 	if (!tusb_dma->multichannel)
174 		tusb_omap_free_shared_dmareq(chdat);
175 
176 	channel->status = MUSB_DMA_STATUS_FREE;
177 
178 	/* Handle only RX callbacks here. TX callbacks must be handled based
179 	 * on the TUSB DMA status interrupt.
180 	 * REVISIT: Use both TUSB DMA status interrupt and OMAP DMA callback
181 	 * interrupt for RX and TX.
182 	 */
183 	if (!chdat->tx)
184 		musb_dma_completion(musb, chdat->epnum, chdat->tx);
185 
186 	/* We must terminate short tx transfers manually by setting TXPKTRDY.
187 	 * REVISIT: This same problem may occur with other MUSB dma as well.
188 	 * Easy to test with g_ether by pinging the MUSB board with ping -s54.
189 	 */
190 	if ((chdat->transfer_len < chdat->packet_sz)
191 			|| (chdat->transfer_len % chdat->packet_sz != 0)) {
192 		u16	csr;
193 
194 		if (chdat->tx) {
195 			dev_dbg(musb->controller, "terminating short tx packet\n");
196 			musb_ep_select(mbase, chdat->epnum);
197 			csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
198 			csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY
199 				| MUSB_TXCSR_P_WZC_BITS;
200 			musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
201 		}
202 	}
203 
204 	spin_unlock_irqrestore(&musb->lock, flags);
205 }
206 
207 static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
208 				u8 rndis_mode, dma_addr_t dma_addr, u32 len)
209 {
210 	struct tusb_omap_dma_ch		*chdat = to_chdat(channel);
211 	struct tusb_omap_dma		*tusb_dma = chdat->tusb_dma;
212 	struct musb			*musb = chdat->musb;
213 	struct device			*dev = musb->controller;
214 	struct musb_hw_ep		*hw_ep = chdat->hw_ep;
215 	void __iomem			*mbase = musb->mregs;
216 	void __iomem			*ep_conf = hw_ep->conf;
217 	dma_addr_t			fifo = hw_ep->fifo_sync;
218 	struct omap_dma_channel_params	dma_params;
219 	u32				dma_remaining;
220 	int				src_burst, dst_burst;
221 	u16				csr;
222 	int				ch;
223 	s8				dmareq;
224 	s8				sync_dev;
225 
226 	if (unlikely(dma_addr & 0x1) || (len < 32) || (len > packet_sz))
227 		return false;
228 
229 	/*
230 	 * HW issue #10: Async dma will eventually corrupt the XFR_SIZE
231 	 * register which will cause missed DMA interrupt. We could try to
232 	 * use a timer for the callback, but it is unsafe as the XFR_SIZE
233 	 * register is corrupt, and we won't know if the DMA worked.
234 	 */
235 	if (dma_addr & 0x2)
236 		return false;
237 
238 	/*
239 	 * Because of HW issue #10, it seems like mixing sync DMA and async
240 	 * PIO access can confuse the DMA. Make sure XFR_SIZE is reset before
241 	 * using the channel for DMA.
242 	 */
243 	if (chdat->tx)
244 		dma_remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
245 	else
246 		dma_remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
247 
248 	dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
249 	if (dma_remaining) {
250 		dev_dbg(musb->controller, "Busy %s dma ch%i, not using: %08x\n",
251 			chdat->tx ? "tx" : "rx", chdat->ch,
252 			dma_remaining);
253 		return false;
254 	}
255 
256 	chdat->transfer_len = len & ~0x1f;
257 
258 	if (len < packet_sz)
259 		chdat->transfer_packet_sz = chdat->transfer_len;
260 	else
261 		chdat->transfer_packet_sz = packet_sz;
262 
263 	if (tusb_dma->multichannel) {
264 		ch = chdat->ch;
265 		dmareq = chdat->dmareq;
266 		sync_dev = chdat->sync_dev;
267 	} else {
268 		if (tusb_omap_use_shared_dmareq(chdat) != 0) {
269 			dev_dbg(musb->controller, "could not get dma for ep%i\n", chdat->epnum);
270 			return false;
271 		}
272 		if (tusb_dma->ch < 0) {
273 			/* REVISIT: This should get blocked earlier, happens
274 			 * with MSC ErrorRecoveryTest
275 			 */
276 			WARN_ON(1);
277 			return false;
278 		}
279 
280 		ch = tusb_dma->ch;
281 		dmareq = tusb_dma->dmareq;
282 		sync_dev = tusb_dma->sync_dev;
283 		omap_set_dma_callback(ch, tusb_omap_dma_cb, channel);
284 	}
285 
286 	chdat->packet_sz = packet_sz;
287 	chdat->len = len;
288 	channel->actual_len = 0;
289 	chdat->dma_addr = dma_addr;
290 	channel->status = MUSB_DMA_STATUS_BUSY;
291 
292 	/* Since we're recycling dma areas, we need to clean or invalidate */
293 	if (chdat->tx)
294 		dma_map_single(dev, phys_to_virt(dma_addr), len,
295 				DMA_TO_DEVICE);
296 	else
297 		dma_map_single(dev, phys_to_virt(dma_addr), len,
298 				DMA_FROM_DEVICE);
299 
300 	/* Use 16-bit transfer if dma_addr is not 32-bit aligned */
301 	if ((dma_addr & 0x3) == 0) {
302 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S32;
303 		dma_params.elem_count = 8;		/* Elements in frame */
304 	} else {
305 		dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
306 		dma_params.elem_count = 16;		/* Elements in frame */
307 		fifo = hw_ep->fifo_async;
308 	}
309 
310 	dma_params.frame_count	= chdat->transfer_len / 32; /* Burst sz frame */
311 
312 	dev_dbg(musb->controller, "ep%i %s dma ch%i dma: %pad len: %u(%u) packet_sz: %i(%i)\n",
313 		chdat->epnum, chdat->tx ? "tx" : "rx",
314 		ch, &dma_addr, chdat->transfer_len, len,
315 		chdat->transfer_packet_sz, packet_sz);
316 
317 	/*
318 	 * Prepare omap DMA for transfer
319 	 */
320 	if (chdat->tx) {
321 		dma_params.src_amode	= OMAP_DMA_AMODE_POST_INC;
322 		dma_params.src_start	= (unsigned long)dma_addr;
323 		dma_params.src_ei	= 0;
324 		dma_params.src_fi	= 0;
325 
326 		dma_params.dst_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
327 		dma_params.dst_start	= (unsigned long)fifo;
328 		dma_params.dst_ei	= 1;
329 		dma_params.dst_fi	= -31;	/* Loop 32 byte window */
330 
331 		dma_params.trigger	= sync_dev;
332 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
333 		dma_params.src_or_dst_synch	= 0;	/* Dest sync */
334 
335 		src_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 read */
336 		dst_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 write */
337 	} else {
338 		dma_params.src_amode	= OMAP_DMA_AMODE_DOUBLE_IDX;
339 		dma_params.src_start	= (unsigned long)fifo;
340 		dma_params.src_ei	= 1;
341 		dma_params.src_fi	= -31;	/* Loop 32 byte window */
342 
343 		dma_params.dst_amode	= OMAP_DMA_AMODE_POST_INC;
344 		dma_params.dst_start	= (unsigned long)dma_addr;
345 		dma_params.dst_ei	= 0;
346 		dma_params.dst_fi	= 0;
347 
348 		dma_params.trigger	= sync_dev;
349 		dma_params.sync_mode	= OMAP_DMA_SYNC_FRAME;
350 		dma_params.src_or_dst_synch	= 1;	/* Source sync */
351 
352 		src_burst = OMAP_DMA_DATA_BURST_8;	/* 8x32 read */
353 		dst_burst = OMAP_DMA_DATA_BURST_16;	/* 16x32 write */
354 	}
355 
356 	dev_dbg(musb->controller, "ep%i %s using %i-bit %s dma from 0x%08lx to 0x%08lx\n",
357 		chdat->epnum, chdat->tx ? "tx" : "rx",
358 		(dma_params.data_type == OMAP_DMA_DATA_TYPE_S32) ? 32 : 16,
359 		((dma_addr & 0x3) == 0) ? "sync" : "async",
360 		dma_params.src_start, dma_params.dst_start);
361 
362 	omap_set_dma_params(ch, &dma_params);
363 	omap_set_dma_src_burst_mode(ch, src_burst);
364 	omap_set_dma_dest_burst_mode(ch, dst_burst);
365 	omap_set_dma_write_mode(ch, OMAP_DMA_WRITE_LAST_NON_POSTED);
366 
367 	/*
368 	 * Prepare MUSB for DMA transfer
369 	 */
370 	if (chdat->tx) {
371 		musb_ep_select(mbase, chdat->epnum);
372 		csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
373 		csr |= (MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB
374 			| MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
375 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
376 		musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
377 	} else {
378 		musb_ep_select(mbase, chdat->epnum);
379 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
380 		csr |= MUSB_RXCSR_DMAENAB;
381 		csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAMODE);
382 		musb_writew(hw_ep->regs, MUSB_RXCSR,
383 			csr | MUSB_RXCSR_P_WZC_BITS);
384 	}
385 
386 	/*
387 	 * Start DMA transfer
388 	 */
389 	omap_start_dma(ch);
390 
391 	if (chdat->tx) {
392 		/* Send transfer_packet_sz packets at a time */
393 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
394 			chdat->transfer_packet_sz);
395 
396 		musb_writel(ep_conf, TUSB_EP_TX_OFFSET,
397 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
398 	} else {
399 		/* Receive transfer_packet_sz packets at a time */
400 		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
401 			chdat->transfer_packet_sz << 16);
402 
403 		musb_writel(ep_conf, TUSB_EP_RX_OFFSET,
404 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
405 	}
406 
407 	return true;
408 }
409 
410 static int tusb_omap_dma_abort(struct dma_channel *channel)
411 {
412 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
413 	struct tusb_omap_dma	*tusb_dma = chdat->tusb_dma;
414 
415 	if (!tusb_dma->multichannel) {
416 		if (tusb_dma->ch >= 0) {
417 			omap_stop_dma(tusb_dma->ch);
418 			omap_free_dma(tusb_dma->ch);
419 			tusb_dma->ch = -1;
420 		}
421 
422 		tusb_dma->dmareq = -1;
423 		tusb_dma->sync_dev = -1;
424 	}
425 
426 	channel->status = MUSB_DMA_STATUS_FREE;
427 
428 	return 0;
429 }
430 
431 static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
432 {
433 	u32		reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
434 	int		i, dmareq_nr = -1;
435 
436 	const int sync_dev[6] = {
437 		OMAP24XX_DMA_EXT_DMAREQ0,
438 		OMAP24XX_DMA_EXT_DMAREQ1,
439 		OMAP242X_DMA_EXT_DMAREQ2,
440 		OMAP242X_DMA_EXT_DMAREQ3,
441 		OMAP242X_DMA_EXT_DMAREQ4,
442 		OMAP242X_DMA_EXT_DMAREQ5,
443 	};
444 
445 	for (i = 0; i < MAX_DMAREQ; i++) {
446 		int cur = (reg & (0xf << (i * 5))) >> (i * 5);
447 		if (cur == 0) {
448 			dmareq_nr = i;
449 			break;
450 		}
451 	}
452 
453 	if (dmareq_nr == -1)
454 		return -EAGAIN;
455 
456 	reg |= (chdat->epnum << (dmareq_nr * 5));
457 	if (chdat->tx)
458 		reg |= ((1 << 4) << (dmareq_nr * 5));
459 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
460 
461 	chdat->dmareq = dmareq_nr;
462 	chdat->sync_dev = sync_dev[chdat->dmareq];
463 
464 	return 0;
465 }
466 
467 static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
468 {
469 	u32 reg;
470 
471 	if (!chdat || chdat->dmareq < 0)
472 		return;
473 
474 	reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
475 	reg &= ~(0x1f << (chdat->dmareq * 5));
476 	musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
477 
478 	chdat->dmareq = -1;
479 	chdat->sync_dev = -1;
480 }
481 
482 static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
483 
484 static struct dma_channel *
485 tusb_omap_dma_allocate(struct dma_controller *c,
486 		struct musb_hw_ep *hw_ep,
487 		u8 tx)
488 {
489 	int ret, i;
490 	const char		*dev_name;
491 	struct tusb_omap_dma	*tusb_dma;
492 	struct musb		*musb;
493 	void __iomem		*tbase;
494 	struct dma_channel	*channel = NULL;
495 	struct tusb_omap_dma_ch	*chdat = NULL;
496 	u32			reg;
497 
498 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
499 	musb = tusb_dma->controller.musb;
500 	tbase = musb->ctrl_base;
501 
502 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
503 	if (tx)
504 		reg &= ~(1 << hw_ep->epnum);
505 	else
506 		reg &= ~(1 << (hw_ep->epnum + 15));
507 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
508 
509 	/* REVISIT: Why does dmareq5 not work? */
510 	if (hw_ep->epnum == 0) {
511 		dev_dbg(musb->controller, "Not allowing DMA for ep0 %s\n", tx ? "tx" : "rx");
512 		return NULL;
513 	}
514 
515 	for (i = 0; i < MAX_DMAREQ; i++) {
516 		struct dma_channel *ch = dma_channel_pool[i];
517 		if (ch->status == MUSB_DMA_STATUS_UNKNOWN) {
518 			ch->status = MUSB_DMA_STATUS_FREE;
519 			channel = ch;
520 			chdat = ch->private_data;
521 			break;
522 		}
523 	}
524 
525 	if (!channel)
526 		return NULL;
527 
528 	if (tx) {
529 		chdat->tx = 1;
530 		dev_name = "TUSB transmit";
531 	} else {
532 		chdat->tx = 0;
533 		dev_name = "TUSB receive";
534 	}
535 
536 	chdat->musb = tusb_dma->controller.musb;
537 	chdat->tbase = tusb_dma->tbase;
538 	chdat->hw_ep = hw_ep;
539 	chdat->epnum = hw_ep->epnum;
540 	chdat->dmareq = -1;
541 	chdat->completed_len = 0;
542 	chdat->tusb_dma = tusb_dma;
543 
544 	channel->max_len = 0x7fffffff;
545 	channel->desired_mode = 0;
546 	channel->actual_len = 0;
547 
548 	if (tusb_dma->multichannel) {
549 		ret = tusb_omap_dma_allocate_dmareq(chdat);
550 		if (ret != 0)
551 			goto free_dmareq;
552 
553 		ret = omap_request_dma(chdat->sync_dev, dev_name,
554 				tusb_omap_dma_cb, channel, &chdat->ch);
555 		if (ret != 0)
556 			goto free_dmareq;
557 	} else if (tusb_dma->ch == -1) {
558 		tusb_dma->dmareq = 0;
559 		tusb_dma->sync_dev = OMAP24XX_DMA_EXT_DMAREQ0;
560 
561 		/* Callback data gets set later in the shared dmareq case */
562 		ret = omap_request_dma(tusb_dma->sync_dev, "TUSB shared",
563 				tusb_omap_dma_cb, NULL, &tusb_dma->ch);
564 		if (ret != 0)
565 			goto free_dmareq;
566 
567 		chdat->dmareq = -1;
568 		chdat->ch = -1;
569 	}
570 
571 	dev_dbg(musb->controller, "ep%i %s dma: %s dma%i dmareq%i sync%i\n",
572 		chdat->epnum,
573 		chdat->tx ? "tx" : "rx",
574 		chdat->ch >= 0 ? "dedicated" : "shared",
575 		chdat->ch >= 0 ? chdat->ch : tusb_dma->ch,
576 		chdat->dmareq >= 0 ? chdat->dmareq : tusb_dma->dmareq,
577 		chdat->sync_dev >= 0 ? chdat->sync_dev : tusb_dma->sync_dev);
578 
579 	return channel;
580 
581 free_dmareq:
582 	tusb_omap_dma_free_dmareq(chdat);
583 
584 	dev_dbg(musb->controller, "ep%i: Could not get a DMA channel\n", chdat->epnum);
585 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
586 
587 	return NULL;
588 }
589 
590 static void tusb_omap_dma_release(struct dma_channel *channel)
591 {
592 	struct tusb_omap_dma_ch	*chdat = to_chdat(channel);
593 	struct musb		*musb = chdat->musb;
594 	void __iomem		*tbase = musb->ctrl_base;
595 	u32			reg;
596 
597 	dev_dbg(musb->controller, "ep%i ch%i\n", chdat->epnum, chdat->ch);
598 
599 	reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
600 	if (chdat->tx)
601 		reg |= (1 << chdat->epnum);
602 	else
603 		reg |= (1 << (chdat->epnum + 15));
604 	musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
605 
606 	reg = musb_readl(tbase, TUSB_DMA_INT_CLEAR);
607 	if (chdat->tx)
608 		reg |= (1 << chdat->epnum);
609 	else
610 		reg |= (1 << (chdat->epnum + 15));
611 	musb_writel(tbase, TUSB_DMA_INT_CLEAR, reg);
612 
613 	channel->status = MUSB_DMA_STATUS_UNKNOWN;
614 
615 	if (chdat->ch >= 0) {
616 		omap_stop_dma(chdat->ch);
617 		omap_free_dma(chdat->ch);
618 		chdat->ch = -1;
619 	}
620 
621 	if (chdat->dmareq >= 0)
622 		tusb_omap_dma_free_dmareq(chdat);
623 
624 	channel = NULL;
625 }
626 
627 void tusb_dma_controller_destroy(struct dma_controller *c)
628 {
629 	struct tusb_omap_dma	*tusb_dma;
630 	int			i;
631 
632 	tusb_dma = container_of(c, struct tusb_omap_dma, controller);
633 	for (i = 0; i < MAX_DMAREQ; i++) {
634 		struct dma_channel *ch = dma_channel_pool[i];
635 		if (ch) {
636 			kfree(ch->private_data);
637 			kfree(ch);
638 		}
639 	}
640 
641 	if (tusb_dma && !tusb_dma->multichannel && tusb_dma->ch >= 0)
642 		omap_free_dma(tusb_dma->ch);
643 
644 	kfree(tusb_dma);
645 }
646 EXPORT_SYMBOL_GPL(tusb_dma_controller_destroy);
647 
648 struct dma_controller *
649 tusb_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->controller.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 (musb->tusb_revision >= 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 	musb_dma_controller_destroy(&tusb_dma->controller);
706 out:
707 	return NULL;
708 }
709 EXPORT_SYMBOL_GPL(tusb_dma_controller_create);
710