1 /*
2 * MUSB OTG driver - support for Mentor's DMA controller
3 *
4 * Copyright 2005 Mentor Graphics Corporation
5 * Copyright (C) 2005-2007 by Texas Instruments
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 *
21 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
24 * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
27 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
28 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 */
33 #include <linux/device.h>
34 #include <linux/interrupt.h>
35 #include <linux/platform_device.h>
36 #include "musb_core.h"
37 #include "musbhsdma.h"
38
39 static int dma_controller_start(struct dma_controller *c)
40 {
41 /* nothing to do */
42 return 0;
43 }
44
45 static void dma_channel_release(struct dma_channel *channel);
46
47 static int dma_controller_stop(struct dma_controller *c)
48 {
49 struct musb_dma_controller *controller = container_of(c,
50 struct musb_dma_controller, controller);
51 struct musb *musb = controller->private_data;
52 struct dma_channel *channel;
53 u8 bit;
54
55 if (controller->used_channels != 0) {
56 dev_err(musb->controller,
57 "Stopping DMA controller while channel active\n");
58
59 for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
60 if (controller->used_channels & (1 << bit)) {
61 channel = &controller->channel[bit].channel;
62 dma_channel_release(channel);
63
64 if (!controller->used_channels)
65 break;
66 }
67 }
68 }
69
70 return 0;
71 }
72
73 static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
74 struct musb_hw_ep *hw_ep, u8 transmit)
75 {
76 struct musb_dma_controller *controller = container_of(c,
77 struct musb_dma_controller, controller);
78 struct musb_dma_channel *musb_channel = NULL;
79 struct dma_channel *channel = NULL;
80 u8 bit;
81
82 for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) {
83 if (!(controller->used_channels & (1 << bit))) {
84 controller->used_channels |= (1 << bit);
85 musb_channel = &(controller->channel[bit]);
86 musb_channel->controller = controller;
87 musb_channel->idx = bit;
88 musb_channel->epnum = hw_ep->epnum;
89 musb_channel->transmit = transmit;
90 channel = &(musb_channel->channel);
91 channel->private_data = musb_channel;
92 channel->status = MUSB_DMA_STATUS_FREE;
93 channel->max_len = 0x10000;
94 /* Tx => mode 1; Rx => mode 0 */
95 channel->desired_mode = transmit;
96 channel->actual_len = 0;
97 break;
98 }
99 }
100
101 return channel;
102 }
103
104 static void dma_channel_release(struct dma_channel *channel)
105 {
106 struct musb_dma_channel *musb_channel = channel->private_data;
107
108 channel->actual_len = 0;
109 musb_channel->start_addr = 0;
110 musb_channel->len = 0;
111
112 musb_channel->controller->used_channels &=
113 ~(1 << musb_channel->idx);
114
115 channel->status = MUSB_DMA_STATUS_UNKNOWN;
116 }
117
118 static void configure_channel(struct dma_channel *channel,
119 u16 packet_sz, u8 mode,
120 dma_addr_t dma_addr, u32 len)
121 {
122 struct musb_dma_channel *musb_channel = channel->private_data;
123 struct musb_dma_controller *controller = musb_channel->controller;
124 void __iomem *mbase = controller->base;
125 u8 bchannel = musb_channel->idx;
126 u16 csr = 0;
127
128 DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
129 channel, packet_sz, dma_addr, len, mode);
130
131 if (mode) {
132 csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
133 BUG_ON(len < packet_sz);
134
135 if (packet_sz >= 64) {
136 csr |= MUSB_HSDMA_BURSTMODE_INCR16
137 << MUSB_HSDMA_BURSTMODE_SHIFT;
138 } else if (packet_sz >= 32) {
139 csr |= MUSB_HSDMA_BURSTMODE_INCR8
140 << MUSB_HSDMA_BURSTMODE_SHIFT;
141 } else if (packet_sz >= 16) {
142 csr |= MUSB_HSDMA_BURSTMODE_INCR4
143 << MUSB_HSDMA_BURSTMODE_SHIFT;
144 }
145 }
146
147 csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
148 | (1 << MUSB_HSDMA_ENABLE_SHIFT)
149 | (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
150 | (musb_channel->transmit
151 ? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
152 : 0);
153
154 /* address/count */
155 musb_write_hsdma_addr(mbase, bchannel, dma_addr);
156 musb_write_hsdma_count(mbase, bchannel, len);
157
158 /* control (this should start things) */
159 musb_writew(mbase,
160 MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
161 csr);
162 }
163
164 static int dma_channel_program(struct dma_channel *channel,
165 u16 packet_sz, u8 mode,
166 dma_addr_t dma_addr, u32 len)
167 {
168 struct musb_dma_channel *musb_channel = channel->private_data;
169
170 DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
171 musb_channel->epnum,
172 musb_channel->transmit ? "Tx" : "Rx",
173 packet_sz, dma_addr, len, mode);
174
175 BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
176 channel->status == MUSB_DMA_STATUS_BUSY);
177
178 channel->actual_len = 0;
179 musb_channel->start_addr = dma_addr;
180 musb_channel->len = len;
181 musb_channel->max_packet_sz = packet_sz;
182 channel->status = MUSB_DMA_STATUS_BUSY;
183
184 if ((mode == 1) && (len >= packet_sz))
185 configure_channel(channel, packet_sz, 1, dma_addr, len);
186 else
187 configure_channel(channel, packet_sz, 0, dma_addr, len);
188
189 return true;
190 }
191
192 static int dma_channel_abort(struct dma_channel *channel)
193 {
194 struct musb_dma_channel *musb_channel = channel->private_data;
195 void __iomem *mbase = musb_channel->controller->base;
196
197 u8 bchannel = musb_channel->idx;
198 int offset;
199 u16 csr;
200
201 if (channel->status == MUSB_DMA_STATUS_BUSY) {
202 if (musb_channel->transmit) {
203 offset = MUSB_EP_OFFSET(musb_channel->epnum,
204 MUSB_TXCSR);
205
206 /*
207 * The programming guide says that we must clear
208 * the DMAENAB bit before the DMAMODE bit...
209 */
210 csr = musb_readw(mbase, offset);
211 csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
212 musb_writew(mbase, offset, csr);
213 csr &= ~MUSB_TXCSR_DMAMODE;
214 musb_writew(mbase, offset, csr);
215 } else {
216 offset = MUSB_EP_OFFSET(musb_channel->epnum,
217 MUSB_RXCSR);
218
219 csr = musb_readw(mbase, offset);
220 csr &= ~(MUSB_RXCSR_AUTOCLEAR |
221 MUSB_RXCSR_DMAENAB |
222 MUSB_RXCSR_DMAMODE);
223 musb_writew(mbase, offset, csr);
224 }
225
226 musb_writew(mbase,
227 MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL),
228 0);
229 musb_write_hsdma_addr(mbase, bchannel, 0);
230 musb_write_hsdma_count(mbase, bchannel, 0);
231 channel->status = MUSB_DMA_STATUS_FREE;
232 }
233
234 return 0;
235 }
236
237 static irqreturn_t dma_controller_irq(int irq, void *private_data)
238 {
239 struct musb_dma_controller *controller = private_data;
240 struct musb *musb = controller->private_data;
241 struct musb_dma_channel *musb_channel;
242 struct dma_channel *channel;
243
244 void __iomem *mbase = controller->base;
245
246 irqreturn_t retval = IRQ_NONE;
247
248 unsigned long flags;
249
250 u8 bchannel;
251 u8 int_hsdma;
252
253 u32 addr;
254 u16 csr;
255
256 spin_lock_irqsave(&musb->lock, flags);
257
258 int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);
259 if (!int_hsdma)
260 goto done;
261
262 for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
263 if (int_hsdma & (1 << bchannel)) {
264 musb_channel = (struct musb_dma_channel *)
265 &(controller->channel[bchannel]);
266 channel = &musb_channel->channel;
267
268 csr = musb_readw(mbase,
269 MUSB_HSDMA_CHANNEL_OFFSET(bchannel,
270 MUSB_HSDMA_CONTROL));
271
272 if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) {
273 musb_channel->channel.status =
274 MUSB_DMA_STATUS_BUS_ABORT;
275 } else {
276 u8 devctl;
277
278 addr = musb_read_hsdma_addr(mbase,
279 bchannel);
280 channel->actual_len = addr
281 - musb_channel->start_addr;
282
283 DBG(2, "ch %p, 0x%x -> 0x%x (%d / %d) %s\n",
284 channel, musb_channel->start_addr,
285 addr, channel->actual_len,
286 musb_channel->len,
287 (channel->actual_len
288 < musb_channel->len) ?
289 "=> reconfig 0" : "=> complete");
290
291 devctl = musb_readb(mbase, MUSB_DEVCTL);
292
293 channel->status = MUSB_DMA_STATUS_FREE;
294
295 /* completed */
296 if ((devctl & MUSB_DEVCTL_HM)
297 && (musb_channel->transmit)
298 && ((channel->desired_mode == 0)
299 || (channel->actual_len &
300 (musb_channel->max_packet_sz - 1)))
301 ) {
302 u8 epnum = musb_channel->epnum;
303 int offset = MUSB_EP_OFFSET(epnum,
304 MUSB_TXCSR);
305 u16 txcsr;
306
307 /*
308 * The programming guide says that we
309 * must clear DMAENAB before DMAMODE.
310 */
311 musb_ep_select(mbase, epnum);
312 txcsr = musb_readw(mbase, offset);
313 txcsr &= ~(MUSB_TXCSR_DMAENAB
314 | MUSB_TXCSR_AUTOSET);
315 musb_writew(mbase, offset, txcsr);
316 /* Send out the packet */
317 txcsr &= ~MUSB_TXCSR_DMAMODE;
318 txcsr |= MUSB_TXCSR_TXPKTRDY;
319 musb_writew(mbase, offset, txcsr);
320 }
321 musb_dma_completion(musb, musb_channel->epnum,
322 musb_channel->transmit);
323 }
324 }
325 }
326
327 #ifdef CONFIG_BLACKFIN
328 /* Clear DMA interrup flags */
329 musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
330 #endif
331
332 retval = IRQ_HANDLED;
333 done:
334 spin_unlock_irqrestore(&musb->lock, flags);
335 return retval;
336 }
337
338 void dma_controller_destroy(struct dma_controller *c)
339 {
340 struct musb_dma_controller *controller = container_of(c,
341 struct musb_dma_controller, controller);
342
343 if (!controller)
344 return;
345
346 if (controller->irq)
347 free_irq(controller->irq, c);
348
349 kfree(controller);
350 }
351
352 struct dma_controller *__init
353 dma_controller_create(struct musb *musb, void __iomem *base)
354 {
355 struct musb_dma_controller *controller;
356 struct device *dev = musb->controller;
357 struct platform_device *pdev = to_platform_device(dev);
358 int irq = platform_get_irq(pdev, 1);
359
360 if (irq == 0) {
361 dev_err(dev, "No DMA interrupt line!\n");
362 return NULL;
363 }
364
365 controller = kzalloc(sizeof(*controller), GFP_KERNEL);
366 if (!controller)
367 return NULL;
368
369 controller->channel_count = MUSB_HSDMA_CHANNELS;
370 controller->private_data = musb;
371 controller->base = base;
372
373 controller->controller.start = dma_controller_start;
374 controller->controller.stop = dma_controller_stop;
375 controller->controller.channel_alloc = dma_channel_allocate;
376 controller->controller.channel_release = dma_channel_release;
377 controller->controller.channel_program = dma_channel_program;
378 controller->controller.channel_abort = dma_channel_abort;
379
380 if (request_irq(irq, dma_controller_irq, IRQF_DISABLED,
381 dev_name(musb->controller), &controller->controller)) {
382 dev_err(dev, "request_irq %d failed!\n", irq);
383 dma_controller_destroy(&controller->controller);
384
385 return NULL;
386 }
387
388 controller->irq = irq;
389
390 return &controller->controller;
391 }
392
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