xref: /openbmc/linux/drivers/usb/musb/musbhsdma.c (revision 384740dc)
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 
38 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3430)
39 #include "omap2430.h"
40 #endif
41 
42 #define MUSB_HSDMA_BASE		0x200
43 #define MUSB_HSDMA_INTR		(MUSB_HSDMA_BASE + 0)
44 #define MUSB_HSDMA_CONTROL		0x4
45 #define MUSB_HSDMA_ADDRESS		0x8
46 #define MUSB_HSDMA_COUNT		0xc
47 
48 #define MUSB_HSDMA_CHANNEL_OFFSET(_bChannel, _offset)		\
49 		(MUSB_HSDMA_BASE + (_bChannel << 4) + _offset)
50 
51 /* control register (16-bit): */
52 #define MUSB_HSDMA_ENABLE_SHIFT		0
53 #define MUSB_HSDMA_TRANSMIT_SHIFT		1
54 #define MUSB_HSDMA_MODE1_SHIFT		2
55 #define MUSB_HSDMA_IRQENABLE_SHIFT		3
56 #define MUSB_HSDMA_ENDPOINT_SHIFT		4
57 #define MUSB_HSDMA_BUSERROR_SHIFT		8
58 #define MUSB_HSDMA_BURSTMODE_SHIFT		9
59 #define MUSB_HSDMA_BURSTMODE		(3 << MUSB_HSDMA_BURSTMODE_SHIFT)
60 #define MUSB_HSDMA_BURSTMODE_UNSPEC	0
61 #define MUSB_HSDMA_BURSTMODE_INCR4	1
62 #define MUSB_HSDMA_BURSTMODE_INCR8	2
63 #define MUSB_HSDMA_BURSTMODE_INCR16	3
64 
65 #define MUSB_HSDMA_CHANNELS		8
66 
67 struct musb_dma_controller;
68 
69 struct musb_dma_channel {
70 	struct dma_channel		Channel;
71 	struct musb_dma_controller	*controller;
72 	u32				dwStartAddress;
73 	u32				len;
74 	u16				wMaxPacketSize;
75 	u8				bIndex;
76 	u8				epnum;
77 	u8				transmit;
78 };
79 
80 struct musb_dma_controller {
81 	struct dma_controller		Controller;
82 	struct musb_dma_channel		aChannel[MUSB_HSDMA_CHANNELS];
83 	void				*pDmaPrivate;
84 	void __iomem			*pCoreBase;
85 	u8				bChannelCount;
86 	u8				bmUsedChannels;
87 	u8				irq;
88 };
89 
90 static int dma_controller_start(struct dma_controller *c)
91 {
92 	/* nothing to do */
93 	return 0;
94 }
95 
96 static void dma_channel_release(struct dma_channel *pChannel);
97 
98 static int dma_controller_stop(struct dma_controller *c)
99 {
100 	struct musb_dma_controller *controller =
101 		container_of(c, struct musb_dma_controller, Controller);
102 	struct musb *musb = (struct musb *) controller->pDmaPrivate;
103 	struct dma_channel *pChannel;
104 	u8 bBit;
105 
106 	if (controller->bmUsedChannels != 0) {
107 		dev_err(musb->controller,
108 			"Stopping DMA controller while channel active\n");
109 
110 		for (bBit = 0; bBit < MUSB_HSDMA_CHANNELS; bBit++) {
111 			if (controller->bmUsedChannels & (1 << bBit)) {
112 				pChannel = &controller->aChannel[bBit].Channel;
113 				dma_channel_release(pChannel);
114 
115 				if (!controller->bmUsedChannels)
116 					break;
117 			}
118 		}
119 	}
120 	return 0;
121 }
122 
123 static struct dma_channel *dma_channel_allocate(struct dma_controller *c,
124 				struct musb_hw_ep *hw_ep, u8 transmit)
125 {
126 	u8 bBit;
127 	struct dma_channel *pChannel = NULL;
128 	struct musb_dma_channel *pImplChannel = NULL;
129 	struct musb_dma_controller *controller =
130 			container_of(c, struct musb_dma_controller, Controller);
131 
132 	for (bBit = 0; bBit < MUSB_HSDMA_CHANNELS; bBit++) {
133 		if (!(controller->bmUsedChannels & (1 << bBit))) {
134 			controller->bmUsedChannels |= (1 << bBit);
135 			pImplChannel = &(controller->aChannel[bBit]);
136 			pImplChannel->controller = controller;
137 			pImplChannel->bIndex = bBit;
138 			pImplChannel->epnum = hw_ep->epnum;
139 			pImplChannel->transmit = transmit;
140 			pChannel = &(pImplChannel->Channel);
141 			pChannel->private_data = pImplChannel;
142 			pChannel->status = MUSB_DMA_STATUS_FREE;
143 			pChannel->max_len = 0x10000;
144 			/* Tx => mode 1; Rx => mode 0 */
145 			pChannel->desired_mode = transmit;
146 			pChannel->actual_len = 0;
147 			break;
148 		}
149 	}
150 	return pChannel;
151 }
152 
153 static void dma_channel_release(struct dma_channel *pChannel)
154 {
155 	struct musb_dma_channel *pImplChannel =
156 		(struct musb_dma_channel *) pChannel->private_data;
157 
158 	pChannel->actual_len = 0;
159 	pImplChannel->dwStartAddress = 0;
160 	pImplChannel->len = 0;
161 
162 	pImplChannel->controller->bmUsedChannels &=
163 		~(1 << pImplChannel->bIndex);
164 
165 	pChannel->status = MUSB_DMA_STATUS_UNKNOWN;
166 }
167 
168 static void configure_channel(struct dma_channel *pChannel,
169 				u16 packet_sz, u8 mode,
170 				dma_addr_t dma_addr, u32 len)
171 {
172 	struct musb_dma_channel *pImplChannel =
173 		(struct musb_dma_channel *) pChannel->private_data;
174 	struct musb_dma_controller *controller = pImplChannel->controller;
175 	void __iomem *mbase = controller->pCoreBase;
176 	u8 bChannel = pImplChannel->bIndex;
177 	u16 csr = 0;
178 
179 	DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n",
180 			pChannel, packet_sz, dma_addr, len, mode);
181 
182 	if (mode) {
183 		csr |= 1 << MUSB_HSDMA_MODE1_SHIFT;
184 		BUG_ON(len < packet_sz);
185 
186 		if (packet_sz >= 64) {
187 			csr |= MUSB_HSDMA_BURSTMODE_INCR16
188 					<< MUSB_HSDMA_BURSTMODE_SHIFT;
189 		} else if (packet_sz >= 32) {
190 			csr |= MUSB_HSDMA_BURSTMODE_INCR8
191 					<< MUSB_HSDMA_BURSTMODE_SHIFT;
192 		} else if (packet_sz >= 16) {
193 			csr |= MUSB_HSDMA_BURSTMODE_INCR4
194 					<< MUSB_HSDMA_BURSTMODE_SHIFT;
195 		}
196 	}
197 
198 	csr |= (pImplChannel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT)
199 		| (1 << MUSB_HSDMA_ENABLE_SHIFT)
200 		| (1 << MUSB_HSDMA_IRQENABLE_SHIFT)
201 		| (pImplChannel->transmit
202 				? (1 << MUSB_HSDMA_TRANSMIT_SHIFT)
203 				: 0);
204 
205 	/* address/count */
206 	musb_writel(mbase,
207 		MUSB_HSDMA_CHANNEL_OFFSET(bChannel, MUSB_HSDMA_ADDRESS),
208 		dma_addr);
209 	musb_writel(mbase,
210 		MUSB_HSDMA_CHANNEL_OFFSET(bChannel, MUSB_HSDMA_COUNT),
211 		len);
212 
213 	/* control (this should start things) */
214 	musb_writew(mbase,
215 		MUSB_HSDMA_CHANNEL_OFFSET(bChannel, MUSB_HSDMA_CONTROL),
216 		csr);
217 }
218 
219 static int dma_channel_program(struct dma_channel *pChannel,
220 				u16 packet_sz, u8 mode,
221 				dma_addr_t dma_addr, u32 len)
222 {
223 	struct musb_dma_channel *pImplChannel =
224 			(struct musb_dma_channel *) pChannel->private_data;
225 
226 	DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n",
227 		pImplChannel->epnum,
228 		pImplChannel->transmit ? "Tx" : "Rx",
229 		packet_sz, dma_addr, len, mode);
230 
231 	BUG_ON(pChannel->status == MUSB_DMA_STATUS_UNKNOWN ||
232 		pChannel->status == MUSB_DMA_STATUS_BUSY);
233 
234 	pChannel->actual_len = 0;
235 	pImplChannel->dwStartAddress = dma_addr;
236 	pImplChannel->len = len;
237 	pImplChannel->wMaxPacketSize = packet_sz;
238 	pChannel->status = MUSB_DMA_STATUS_BUSY;
239 
240 	if ((mode == 1) && (len >= packet_sz))
241 		configure_channel(pChannel, packet_sz, 1, dma_addr, len);
242 	else
243 		configure_channel(pChannel, packet_sz, 0, dma_addr, len);
244 
245 	return true;
246 }
247 
248 static int dma_channel_abort(struct dma_channel *pChannel)
249 {
250 	struct musb_dma_channel *pImplChannel =
251 		(struct musb_dma_channel *) pChannel->private_data;
252 	u8 bChannel = pImplChannel->bIndex;
253 	void __iomem *mbase = pImplChannel->controller->pCoreBase;
254 	u16 csr;
255 
256 	if (pChannel->status == MUSB_DMA_STATUS_BUSY) {
257 		if (pImplChannel->transmit) {
258 
259 			csr = musb_readw(mbase,
260 				MUSB_EP_OFFSET(pImplChannel->epnum,
261 						MUSB_TXCSR));
262 			csr &= ~(MUSB_TXCSR_AUTOSET |
263 				 MUSB_TXCSR_DMAENAB |
264 				 MUSB_TXCSR_DMAMODE);
265 			musb_writew(mbase,
266 				MUSB_EP_OFFSET(pImplChannel->epnum,
267 						MUSB_TXCSR),
268 				csr);
269 		} else {
270 			csr = musb_readw(mbase,
271 				MUSB_EP_OFFSET(pImplChannel->epnum,
272 						MUSB_RXCSR));
273 			csr &= ~(MUSB_RXCSR_AUTOCLEAR |
274 				 MUSB_RXCSR_DMAENAB |
275 				 MUSB_RXCSR_DMAMODE);
276 			musb_writew(mbase,
277 				MUSB_EP_OFFSET(pImplChannel->epnum,
278 						MUSB_RXCSR),
279 				csr);
280 		}
281 
282 		musb_writew(mbase,
283 			MUSB_HSDMA_CHANNEL_OFFSET(bChannel, MUSB_HSDMA_CONTROL),
284 			0);
285 		musb_writel(mbase,
286 			MUSB_HSDMA_CHANNEL_OFFSET(bChannel, MUSB_HSDMA_ADDRESS),
287 			0);
288 		musb_writel(mbase,
289 			MUSB_HSDMA_CHANNEL_OFFSET(bChannel, MUSB_HSDMA_COUNT),
290 			0);
291 
292 		pChannel->status = MUSB_DMA_STATUS_FREE;
293 	}
294 	return 0;
295 }
296 
297 static irqreturn_t dma_controller_irq(int irq, void *private_data)
298 {
299 	struct musb_dma_controller *controller =
300 		(struct musb_dma_controller *)private_data;
301 	struct musb_dma_channel *pImplChannel;
302 	struct musb *musb = controller->pDmaPrivate;
303 	void __iomem *mbase = controller->pCoreBase;
304 	struct dma_channel *pChannel;
305 	u8 bChannel;
306 	u16 csr;
307 	u32 dwAddress;
308 	u8 int_hsdma;
309 	irqreturn_t retval = IRQ_NONE;
310 	unsigned long flags;
311 
312 	spin_lock_irqsave(&musb->lock, flags);
313 
314 	int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR);
315 	if (!int_hsdma)
316 		goto done;
317 
318 	for (bChannel = 0; bChannel < MUSB_HSDMA_CHANNELS; bChannel++) {
319 		if (int_hsdma & (1 << bChannel)) {
320 			pImplChannel = (struct musb_dma_channel *)
321 					&(controller->aChannel[bChannel]);
322 			pChannel = &pImplChannel->Channel;
323 
324 			csr = musb_readw(mbase,
325 					MUSB_HSDMA_CHANNEL_OFFSET(bChannel,
326 							MUSB_HSDMA_CONTROL));
327 
328 			if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT))
329 				pImplChannel->Channel.status =
330 					MUSB_DMA_STATUS_BUS_ABORT;
331 			else {
332 				u8 devctl;
333 
334 				dwAddress = musb_readl(mbase,
335 						MUSB_HSDMA_CHANNEL_OFFSET(
336 							bChannel,
337 							MUSB_HSDMA_ADDRESS));
338 				pChannel->actual_len = dwAddress
339 					- pImplChannel->dwStartAddress;
340 
341 				DBG(2, "ch %p, 0x%x -> 0x%x (%d / %d) %s\n",
342 					pChannel, pImplChannel->dwStartAddress,
343 					dwAddress, pChannel->actual_len,
344 					pImplChannel->len,
345 					(pChannel->actual_len
346 						< pImplChannel->len) ?
347 					"=> reconfig 0" : "=> complete");
348 
349 				devctl = musb_readb(mbase, MUSB_DEVCTL);
350 
351 				pChannel->status = MUSB_DMA_STATUS_FREE;
352 
353 				/* completed */
354 				if ((devctl & MUSB_DEVCTL_HM)
355 					&& (pImplChannel->transmit)
356 					&& ((pChannel->desired_mode == 0)
357 					    || (pChannel->actual_len &
358 					    (pImplChannel->wMaxPacketSize - 1)))
359 					 ) {
360 					/* Send out the packet */
361 					musb_ep_select(mbase,
362 						pImplChannel->epnum);
363 					musb_writew(mbase, MUSB_EP_OFFSET(
364 							pImplChannel->epnum,
365 							MUSB_TXCSR),
366 						MUSB_TXCSR_TXPKTRDY);
367 				} else
368 					musb_dma_completion(
369 						musb,
370 						pImplChannel->epnum,
371 						pImplChannel->transmit);
372 			}
373 		}
374 	}
375 	retval = IRQ_HANDLED;
376 done:
377 	spin_unlock_irqrestore(&musb->lock, flags);
378 	return retval;
379 }
380 
381 void dma_controller_destroy(struct dma_controller *c)
382 {
383 	struct musb_dma_controller *controller;
384 
385 	controller = container_of(c, struct musb_dma_controller, Controller);
386 	if (!controller)
387 		return;
388 
389 	if (controller->irq)
390 		free_irq(controller->irq, c);
391 
392 	kfree(controller);
393 }
394 
395 struct dma_controller *__init
396 dma_controller_create(struct musb *musb, void __iomem *pCoreBase)
397 {
398 	struct musb_dma_controller *controller;
399 	struct device *dev = musb->controller;
400 	struct platform_device *pdev = to_platform_device(dev);
401 	int irq = platform_get_irq(pdev, 1);
402 
403 	if (irq == 0) {
404 		dev_err(dev, "No DMA interrupt line!\n");
405 		return NULL;
406 	}
407 
408 	controller = kzalloc(sizeof(struct musb_dma_controller), GFP_KERNEL);
409 	if (!controller)
410 		return NULL;
411 
412 	controller->bChannelCount = MUSB_HSDMA_CHANNELS;
413 	controller->pDmaPrivate = musb;
414 	controller->pCoreBase = pCoreBase;
415 
416 	controller->Controller.start = dma_controller_start;
417 	controller->Controller.stop = dma_controller_stop;
418 	controller->Controller.channel_alloc = dma_channel_allocate;
419 	controller->Controller.channel_release = dma_channel_release;
420 	controller->Controller.channel_program = dma_channel_program;
421 	controller->Controller.channel_abort = dma_channel_abort;
422 
423 	if (request_irq(irq, dma_controller_irq, IRQF_DISABLED,
424 			musb->controller->bus_id, &controller->Controller)) {
425 		dev_err(dev, "request_irq %d failed!\n", irq);
426 		dma_controller_destroy(&controller->Controller);
427 		return NULL;
428 	}
429 
430 	controller->irq = irq;
431 
432 	return &controller->Controller;
433 }
434