aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/musb/musbhsdma.c
blob: c1be687e00ec722524f8807ff8d628ec7a5d0798 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
/*
 * MUSB OTG driver - support for Mentor's DMA controller
 *
 * Copyright 2005 Mentor Graphics Corporation
 * Copyright (C) 2005-2007 by Texas Instruments
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "musb_core.h"
#include "musbhsdma.h"

static int dma_controller_start(struct dma_controller *c)
{
	/* nothing to do */
	return 0;
}

static void dma_channel_release(struct dma_channel *channel);

static int dma_controller_stop(struct dma_controller *c)
{
	struct musb_dma_controller *controller = container_of(c,
			struct musb_dma_controller, controller);
	struct musb *musb = controller->private_data;
	struct dma_channel *channel;
	u8 bit;

	if (controller->used_channels != 0) {
		dev_err(musb->controller,
			"Stopping DMA controller while channel active\n");

		for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
			if (controller->used_channels & (1 << bit)) {
				channel = &controller->channel[bit].channel;
				dma_channel_release(channel);

				if (!controller->used_channels)
					break;
			}
		}
	}

	return 0;
}

static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
				struct musb_hw_ep *hw_ep, u8 transmit)
{
	struct musb_dma_controller *controller = container_of(c,
			struct musb_dma_controller, controller);
	struct musb_dma_channel *musb_channel = NULL;
	struct dma_channel *channel = NULL;
	u8 bit;

	for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
		if (!(controller->used_channels & (1 << bit))) {
			controller->used_channels |= (1 << bit);
			musb_channel = &(controller->channel[bit]);
			musb_channel->controller = controller;
			musb_channel->idx = bit;
			musb_channel->epnum = hw_ep->epnum;
			musb_channel->transmit = transmit;
			channel = &(musb_channel->channel);
			channel->private_data = musb_channel;
			channel->status = MUSB_DMA_STATUS_FREE;
			channel->max_len = 0x100000;
			/* Tx => mode 1; Rx => mode 0 */
			channel->desired_mode = transmit;
			channel->actual_len = 0;
			break;
		}
	}

	return channel;
}

static void dma_channel_release(struct dma_channel *channel)
{
	struct musb_dma_channel *musb_channel = channel->private_data;

	channel->actual_len = 0;
	musb_channel->start_addr = 0;
	musb_channel->len = 0;

	musb_channel->controller->used_channels &=
		~(1 << musb_channel->idx);

	channel->status = MUSB_DMA_STATUS_UNKNOWN;
}

static void configure_channel(struct dma_channel *channel,
				u16 packet_sz, u8 mode,
				dma_addr_t dma_addr, u32 len)
{
	struct musb_dma_channel *musb_channel = channel->private_data;
	struct musb_dma_controller *controller = musb_channel->controller;
	struct musb *musb = controller->private_data;
	void __iomem *mbase = controller->base;
	u8 bchannel = musb_channel->idx;
	u16 csr = 0;

	dev_dbg(musb->controller, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
			channel, packet_sz, dma_addr, len, mode);

	if (mode) {
		csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
		BUG_ON(len < packet_sz);
	}
	csr |= MUSB_HSDMA_BURSTMODE_INCR16
				<< MUSB_HSDMA_BURSTMODE_SHIFT;

	csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
		| (1 << MUSB_HSDMA_ENABLE_SHIFT)
		| (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
		| (musb_channel->transmit
				? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
				: 0);

	/* address/count */
	musb_write_hsdma_addr(mbase, bchannel, dma_addr);
	musb_write_hsdma_count(mbase, bchannel, len);

	/* control (this should start things) */
	musb_writew(mbase,
		MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
		csr);
}

static int dma_channel_program(struct dma_channel *channel,
				u16 packet_sz, u8 mode,
				dma_addr_t dma_addr, u32 len)
{
	struct musb_dma_channel *musb_channel = channel->private_data;
	struct musb_dma_controller *controller = musb_channel->controller;
	struct musb *musb = controller->private_data;

	dev_dbg(musb->controller, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
		musb_channel->epnum,
		musb_channel->transmit ? "Tx" : "Rx",
		packet_sz, dma_addr, len, mode);

	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
		channel->status == MUSB_DMA_STATUS_BUSY);

	/* Let targets check/tweak the arguments */
	if (musb->ops->adjust_channel_params) {
		int ret = musb->ops->adjust_channel_params(channel,
			packet_sz, &mode, &dma_addr, &len);
		if (ret)
			return ret;
	}

	/*
	 * The DMA engine in RTL1.8 and above cannot handle
	 * DMA addresses that are not aligned to a 4 byte boundary.
	 * It ends up masking the last two bits of the address
	 * programmed in DMA_ADDR.
	 *
	 * Fail such DMA transfers, so that the backup PIO mode
	 * can carry out the transfer
	 */
	if ((musb->hwvers >= MUSB_HWVERS_1800) && (dma_addr % 4))
		return false;

	channel->actual_len = 0;
	musb_channel->start_addr = dma_addr;
	musb_channel->len = len;
	musb_channel->max_packet_sz = packet_sz;
	channel->status = MUSB_DMA_STATUS_BUSY;

	configure_channel(channel, packet_sz, mode, dma_addr, len);

	return true;
}

static int dma_channel_abort(struct dma_channel *channel)
{
	struct musb_dma_channel *musb_channel = channel->private_data;
	void __iomem *mbase = musb_channel->controller->base;

	u8 bchannel = musb_channel->idx;
	int offset;
	u16 csr;

	if (channel->status == MUSB_DMA_STATUS_BUSY) {
		if (musb_channel->transmit) {
			offset = MUSB_EP_OFFSET(musb_channel->epnum,
						MUSB_TXCSR);

			/*
			 * The programming guide says that we must clear
			 * the DMAENAB bit before the DMAMODE bit...
			 */
			csr = musb_readw(mbase, offset);
			csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
			musb_writew(mbase, offset, csr);
			csr &= ~MUSB_TXCSR_DMAMODE;
			musb_writew(mbase, offset, csr);
		} else {
			offset = MUSB_EP_OFFSET(musb_channel->epnum,
						MUSB_RXCSR);

			csr = musb_readw(mbase, offset);
			csr &= ~(MUSB_RXCSR_AUTOCLEAR |
				 MUSB_RXCSR_DMAENAB |
				 MUSB_RXCSR_DMAMODE);
			musb_writew(mbase, offset, csr);
		}

		musb_writew(mbase,
			MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
			0);
		musb_write_hsdma_addr(mbase, bchannel, 0);
		musb_write_hsdma_count(mbase, bchannel, 0);
		channel->status = MUSB_DMA_STATUS_FREE;
	}

	return 0;
}

static irqreturn_t dma_controller_irq(int irq, void *private_data)
{
	struct musb_dma_controller *controller = private_data;
	struct musb *musb = controller->private_data;
	struct musb_dma_channel *musb_channel;
	struct dma_channel *channel;

	void __iomem *mbase = controller->base;

	irqreturn_t retval = IRQ_NONE;

	unsigned long flags;

	u8 bchannel;
	u8 int_hsdma;

	u32 addr, count;
	u16 csr;

	spin_lock_irqsave(&musb->lock, flags);

	int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);

#ifdef CONFIG_BLACKFIN
	/* Clear DMA interrupt flags */
	musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
#endif

	if (!int_hsdma) {
		dev_dbg(musb->controller, "spurious DMA irq\n");

		for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
			musb_channel = (struct musb_dma_channel *)
					&(controller->channel[bchannel]);
			channel = &musb_channel->channel;
			if (channel->status == MUSB_DMA_STATUS_BUSY) {
				count = musb_read_hsdma_count(mbase, bchannel);

				if (count == 0)
					int_hsdma |= (1 << bchannel);
			}
		}

		dev_dbg(musb->controller, "int_hsdma = 0x%x\n", int_hsdma);

		if (!int_hsdma)
			goto done;
	}

	for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
		if (int_hsdma & (1 << bchannel)) {
			musb_channel = (struct musb_dma_channel *)
					&(controller->channel[bchannel]);
			channel = &musb_channel->channel;

			csr = musb_readw(mbase,
					MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
							MUSB_HSDMA_CONTROL));

			if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
				musb_channel->channel.status =
					MUSB_DMA_STATUS_BUS_ABORT;
			} else {
				u8 devctl;

				addr = musb_read_hsdma_addr(mbase,
						bchannel);
				channel->actual_len = addr
					- musb_channel->start_addr;

				dev_dbg(musb->controller, "ch %p, 0x%x -> 0x%x (%zu / %d) %s\n",
					channel, musb_channel->start_addr,
					addr, channel->actual_len,
					musb_channel->len,
					(channel->actual_len
						< musb_channel->len) ?
					"=> reconfig 0" : "=> complete");

				devctl = musb_readb(mbase, MUSB_DEVCTL);

				channel->status = MUSB_DMA_STATUS_FREE;

				/* completed */
				if ((devctl & MUSB_DEVCTL_HM)
					&& (musb_channel->transmit)
					&& ((channel->desired_mode == 0)
					    || (channel->actual_len &
					    (musb_channel->max_packet_sz - 1)))
				    ) {
					u8  epnum  = musb_channel->epnum;
					int offset = MUSB_EP_OFFSET(epnum,
								    MUSB_TXCSR);
					u16 txcsr;

					/*
					 * The programming guide says that we
					 * must clear DMAENAB before DMAMODE.
					 */
					musb_ep_select(mbase, epnum);
					txcsr = musb_readw(mbase, offset);
					txcsr &= ~(MUSB_TXCSR_DMAENAB
							| MUSB_TXCSR_AUTOSET);
					musb_writew(mbase, offset, txcsr);
					/* Send out the packet */
					txcsr &= ~MUSB_TXCSR_DMAMODE;
					txcsr |=  MUSB_TXCSR_TXPKTRDY;
					musb_writew(mbase, offset, txcsr);
				}
				musb_dma_completion(musb, musb_channel->epnum,
						    musb_channel->transmit);
			}
		}
	}

	retval = IRQ_HANDLED;
done:
	spin_unlock_irqrestore(&musb->lock, flags);
	return retval;
}

void dma_controller_destroy(struct dma_controller *c)
{
	struct musb_dma_controller *controller = container_of(c,
			struct musb_dma_controller, controller);

	if (!controller)
		return;

	if (controller->irq)
		free_irq(controller->irq, c);

	kfree(controller);
}

struct dma_controller *__init
dma_controller_create(struct musb *musb, void __iomem *base)
{
	struct musb_dma_controller *controller;
	struct device *dev = musb->controller;
	struct platform_device *pdev = to_platform_device(dev);
	int irq = platform_get_irq_byname(pdev, "dma");

	if (irq <= 0) {
		dev_err(dev, "No DMA interrupt line!\n");
		return NULL;
	}

	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
	if (!controller)
		return NULL;

	controller->channel_count = MUSB_HSDMA_CHANNELS;
	controller->private_data = musb;
	controller->base = base;

	controller->controller.start = dma_controller_start;
	controller->controller.stop = dma_controller_stop;
	controller->controller.channel_alloc = dma_channel_allocate;
	controller->controller.channel_release = dma_channel_release;
	controller->controller.channel_program = dma_channel_program;
	controller->controller.channel_abort = dma_channel_abort;

	if (request_irq(irq, dma_controller_irq, 0,
			dev_name(musb->controller), &controller->controller)) {
		dev_err(dev, "request_irq %d failed!\n", irq);
		dma_controller_destroy(&controller->controller);

		return NULL;
	}

	controller->irq = irq;

	return &controller->controller;
}