summaryrefslogtreecommitdiffstats
path: root/drivers/usb/musb/ux500_dma.c
blob: 97cb45916c4351110e3a21fb2613c2954855ee9b (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
/*
 * drivers/usb/musb/ux500_dma.c
 *
 * U8500 and U5500 DMA support code
 *
 * Copyright (C) 2009 STMicroelectronics
 * Copyright (C) 2011 ST-Ericsson SA
 * Authors:
 *	Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
 *	Praveena Nadahally <praveen.nadahally@stericsson.com>
 *	Rajaram Regupathy <ragupathy.rajaram@stericsson.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/pfn.h>
#include <mach/usb.h>
#include "musb_core.h"

struct ux500_dma_channel {
	struct dma_channel channel;
	struct ux500_dma_controller *controller;
	struct musb_hw_ep *hw_ep;
	struct dma_chan *dma_chan;
	unsigned int cur_len;
	dma_cookie_t cookie;
	u8 ch_num;
	u8 is_tx;
	u8 is_allocated;
};

struct ux500_dma_controller {
	struct dma_controller controller;
	struct ux500_dma_channel rx_channel[UX500_MUSB_DMA_NUM_RX_CHANNELS];
	struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_TX_CHANNELS];
	u32	num_rx_channels;
	u32	num_tx_channels;
	void *private_data;
	dma_addr_t phy_base;
};

/* Work function invoked from DMA callback to handle rx transfers. */
void ux500_dma_callback(void *private_data)
{
	struct dma_channel *channel = private_data;
	struct ux500_dma_channel *ux500_channel = channel->private_data;
	struct musb_hw_ep       *hw_ep = ux500_channel->hw_ep;
	struct musb *musb = hw_ep->musb;
	unsigned long flags;

	dev_dbg(musb->controller, "DMA rx transfer done on hw_ep=%d\n",
		hw_ep->epnum);

	spin_lock_irqsave(&musb->lock, flags);
	ux500_channel->channel.actual_len = ux500_channel->cur_len;
	ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
	musb_dma_completion(musb, hw_ep->epnum,
		ux500_channel->is_tx);
	spin_unlock_irqrestore(&musb->lock, flags);

}

static bool ux500_configure_channel(struct dma_channel *channel,
				u16 packet_sz, u8 mode,
				dma_addr_t dma_addr, u32 len)
{
	struct ux500_dma_channel *ux500_channel = channel->private_data;
	struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
	struct dma_chan *dma_chan = ux500_channel->dma_chan;
	struct dma_async_tx_descriptor *dma_desc;
	enum dma_transfer_direction direction;
	struct scatterlist sg;
	struct dma_slave_config slave_conf;
	enum dma_slave_buswidth addr_width;
	dma_addr_t usb_fifo_addr = (MUSB_FIFO_OFFSET(hw_ep->epnum) +
					ux500_channel->controller->phy_base);
	struct musb *musb = ux500_channel->controller->private_data;

	dev_dbg(musb->controller,
		"packet_sz=%d, mode=%d, dma_addr=0x%x, len=%d is_tx=%d\n",
		packet_sz, mode, dma_addr, len, ux500_channel->is_tx);

	ux500_channel->cur_len = len;

	sg_init_table(&sg, 1);
	sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_addr)), len,
					    offset_in_page(dma_addr));
	sg_dma_address(&sg) = dma_addr;
	sg_dma_len(&sg) = len;

	direction = ux500_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
	addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
					DMA_SLAVE_BUSWIDTH_4_BYTES;

	slave_conf.direction = direction;
	slave_conf.src_addr = usb_fifo_addr;
	slave_conf.src_addr_width = addr_width;
	slave_conf.src_maxburst = 16;
	slave_conf.dst_addr = usb_fifo_addr;
	slave_conf.dst_addr_width = addr_width;
	slave_conf.dst_maxburst = 16;

	dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
					     (unsigned long) &slave_conf);

	dma_desc = dma_chan->device->
			device_prep_slave_sg(dma_chan, &sg, 1, direction,
					     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!dma_desc)
		return false;

	dma_desc->callback = ux500_dma_callback;
	dma_desc->callback_param = channel;
	ux500_channel->cookie = dma_desc->tx_submit(dma_desc);

	dma_async_issue_pending(dma_chan);

	return true;
}

static struct dma_channel *ux500_dma_channel_allocate(struct dma_controller *c,
				struct musb_hw_ep *hw_ep, u8 is_tx)
{
	struct ux500_dma_controller *controller = container_of(c,
			struct ux500_dma_controller, controller);
	struct ux500_dma_channel *ux500_channel = NULL;
	struct musb *musb = controller->private_data;
	u8 ch_num = hw_ep->epnum - 1;
	u32 max_ch;

	/* Max 8 DMA channels (0 - 7). Each DMA channel can only be allocated
	 * to specified hw_ep. For example DMA channel 0 can only be allocated
	 * to hw_ep 1 and 9.
	 */
	if (ch_num > 7)
		ch_num -= 8;

	max_ch = is_tx ? controller->num_tx_channels :
			controller->num_rx_channels;

	if (ch_num >= max_ch)
		return NULL;

	ux500_channel = is_tx ? &(controller->tx_channel[ch_num]) :
				&(controller->rx_channel[ch_num]) ;

	/* Check if channel is already used. */
	if (ux500_channel->is_allocated)
		return NULL;

	ux500_channel->hw_ep = hw_ep;
	ux500_channel->is_allocated = 1;

	dev_dbg(musb->controller, "hw_ep=%d, is_tx=0x%x, channel=%d\n",
		hw_ep->epnum, is_tx, ch_num);

	return &(ux500_channel->channel);
}

static void ux500_dma_channel_release(struct dma_channel *channel)
{
	struct ux500_dma_channel *ux500_channel = channel->private_data;
	struct musb *musb = ux500_channel->controller->private_data;

	dev_dbg(musb->controller, "channel=%d\n", ux500_channel->ch_num);

	if (ux500_channel->is_allocated) {
		ux500_channel->is_allocated = 0;
		channel->status = MUSB_DMA_STATUS_FREE;
		channel->actual_len = 0;
	}
}

static int ux500_dma_is_compatible(struct dma_channel *channel,
		u16 maxpacket, void *buf, u32 length)
{
	if ((maxpacket & 0x3)		||
		((int)buf & 0x3)	||
		(length < 512)		||
		(length & 0x3))
		return false;
	else
		return true;
}

static int ux500_dma_channel_program(struct dma_channel *channel,
				u16 packet_sz, u8 mode,
				dma_addr_t dma_addr, u32 len)
{
	int ret;

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

	if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
		return false;

	channel->status = MUSB_DMA_STATUS_BUSY;
	channel->actual_len = 0;
	ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
	if (!ret)
		channel->status = MUSB_DMA_STATUS_FREE;

	return ret;
}

static int ux500_dma_channel_abort(struct dma_channel *channel)
{
	struct ux500_dma_channel *ux500_channel = channel->private_data;
	struct ux500_dma_controller *controller = ux500_channel->controller;
	struct musb *musb = controller->private_data;
	void __iomem *epio = musb->endpoints[ux500_channel->hw_ep->epnum].regs;
	u16 csr;

	dev_dbg(musb->controller, "channel=%d, is_tx=%d\n",
		ux500_channel->ch_num, ux500_channel->is_tx);

	if (channel->status == MUSB_DMA_STATUS_BUSY) {
		if (ux500_channel->is_tx) {
			csr = musb_readw(epio, MUSB_TXCSR);
			csr &= ~(MUSB_TXCSR_AUTOSET |
				 MUSB_TXCSR_DMAENAB |
				 MUSB_TXCSR_DMAMODE);
			musb_writew(epio, MUSB_TXCSR, csr);
		} else {
			csr = musb_readw(epio, MUSB_RXCSR);
			csr &= ~(MUSB_RXCSR_AUTOCLEAR |
				 MUSB_RXCSR_DMAENAB |
				 MUSB_RXCSR_DMAMODE);
			musb_writew(epio, MUSB_RXCSR, csr);
		}

		ux500_channel->dma_chan->device->
				device_control(ux500_channel->dma_chan,
					DMA_TERMINATE_ALL, 0);
		channel->status = MUSB_DMA_STATUS_FREE;
	}
	return 0;
}

static int ux500_dma_controller_stop(struct dma_controller *c)
{
	struct ux500_dma_controller *controller = container_of(c,
			struct ux500_dma_controller, controller);
	struct ux500_dma_channel *ux500_channel;
	struct dma_channel *channel;
	u8 ch_num;

	for (ch_num = 0; ch_num < controller->num_rx_channels; ch_num++) {
		channel = &controller->rx_channel[ch_num].channel;
		ux500_channel = channel->private_data;

		ux500_dma_channel_release(channel);

		if (ux500_channel->dma_chan)
			dma_release_channel(ux500_channel->dma_chan);
	}

	for (ch_num = 0; ch_num < controller->num_tx_channels; ch_num++) {
		channel = &controller->tx_channel[ch_num].channel;
		ux500_channel = channel->private_data;

		ux500_dma_channel_release(channel);

		if (ux500_channel->dma_chan)
			dma_release_channel(ux500_channel->dma_chan);
	}

	return 0;
}

static int ux500_dma_controller_start(struct dma_controller *c)
{
	struct ux500_dma_controller *controller = container_of(c,
			struct ux500_dma_controller, controller);
	struct ux500_dma_channel *ux500_channel = NULL;
	struct musb *musb = controller->private_data;
	struct device *dev = musb->controller;
	struct musb_hdrc_platform_data *plat = dev->platform_data;
	struct ux500_musb_board_data *data = plat->board_data;
	struct dma_channel *dma_channel = NULL;
	u32 ch_num;
	u8 dir;
	u8 is_tx = 0;

	void **param_array;
	struct ux500_dma_channel *channel_array;
	u32 ch_count;
	dma_cap_mask_t mask;

	if ((data->num_rx_channels > UX500_MUSB_DMA_NUM_RX_CHANNELS) ||
		(data->num_tx_channels > UX500_MUSB_DMA_NUM_TX_CHANNELS))
		return -EINVAL;

	controller->num_rx_channels = data->num_rx_channels;
	controller->num_tx_channels = data->num_tx_channels;

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	/* Prepare the loop for RX channels */
	channel_array = controller->rx_channel;
	ch_count = data->num_rx_channels;
	param_array = data->dma_rx_param_array;

	for (dir = 0; dir < 2; dir++) {
		for (ch_num = 0; ch_num < ch_count; ch_num++) {
			ux500_channel = &channel_array[ch_num];
			ux500_channel->controller = controller;
			ux500_channel->ch_num = ch_num;
			ux500_channel->is_tx = is_tx;

			dma_channel = &(ux500_channel->channel);
			dma_channel->private_data = ux500_channel;
			dma_channel->status = MUSB_DMA_STATUS_FREE;
			dma_channel->max_len = SZ_16M;

			ux500_channel->dma_chan = dma_request_channel(mask,
							data->dma_filter,
							param_array[ch_num]);
			if (!ux500_channel->dma_chan) {
				ERR("Dma pipe allocation error dir=%d ch=%d\n",
					dir, ch_num);

				/* Release already allocated channels */
				ux500_dma_controller_stop(c);

				return -EBUSY;
			}

		}

		/* Prepare the loop for TX channels */
		channel_array = controller->tx_channel;
		ch_count = data->num_tx_channels;
		param_array = data->dma_tx_param_array;
		is_tx = 1;
	}

	return 0;
}

void dma_controller_destroy(struct dma_controller *c)
{
	struct ux500_dma_controller *controller = container_of(c,
			struct ux500_dma_controller, controller);

	kfree(controller);
}

struct dma_controller *__init
dma_controller_create(struct musb *musb, void __iomem *base)
{
	struct ux500_dma_controller *controller;
	struct platform_device *pdev = to_platform_device(musb->controller);
	struct resource	*iomem;

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

	controller->private_data = musb;

	/* Save physical address for DMA controller. */
	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	controller->phy_base = (dma_addr_t) iomem->start;

	controller->controller.start = ux500_dma_controller_start;
	controller->controller.stop = ux500_dma_controller_stop;
	controller->controller.channel_alloc = ux500_dma_channel_allocate;
	controller->controller.channel_release = ux500_dma_channel_release;
	controller->controller.channel_program = ux500_dma_channel_program;
	controller->controller.channel_abort = ux500_dma_channel_abort;
	controller->controller.is_compatible = ux500_dma_is_compatible;

	return &controller->controller;
}
OpenPOWER on IntegriCloud