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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * mtu3_gadget_ep0.c - MediaTek USB3 DRD peripheral driver ep0 handling
  4 *
  5 * Copyright (c) 2016 MediaTek Inc.
  6 *
  7 * Author:  Chunfeng.Yun <chunfeng.yun@mediatek.com>
  8 */
  9
 10#include <linux/usb/composite.h>
 11
 12#include "mtu3.h"
 13
 14/* ep0 is always mtu3->in_eps[0] */
 15#define	next_ep0_request(mtu)	next_request((mtu)->ep0)
 16
 17/* for high speed test mode; see USB 2.0 spec 7.1.20 */
 18static const u8 mtu3_test_packet[53] = {
 19	/* implicit SYNC then DATA0 to start */
 20
 21	/* JKJKJKJK x9 */
 22	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 23	/* JJKKJJKK x8 */
 24	0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
 25	/* JJJJKKKK x8 */
 26	0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee,
 27	/* JJJJJJJKKKKKKK x8 */
 28	0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 29	/* JJJJJJJK x8 */
 30	0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd,
 31	/* JKKKKKKK x10, JK */
 32	0xfc, 0x7e, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0x7e,
 33	/* implicit CRC16 then EOP to end */
 34};
 35
 36static char *decode_ep0_state(struct mtu3 *mtu)
 37{
 38	switch (mtu->ep0_state) {
 39	case MU3D_EP0_STATE_SETUP:
 40		return "SETUP";
 41	case MU3D_EP0_STATE_TX:
 42		return "IN";
 43	case MU3D_EP0_STATE_RX:
 44		return "OUT";
 45	case MU3D_EP0_STATE_TX_END:
 46		return "TX-END";
 47	case MU3D_EP0_STATE_STALL:
 48		return "STALL";
 49	default:
 50		return "??";
 51	}
 52}
 53
 54static void ep0_req_giveback(struct mtu3 *mtu, struct usb_request *req)
 55{
 56	mtu3_req_complete(mtu->ep0, req, 0);
 57}
 58
 59static int
 60forward_to_driver(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
 61__releases(mtu->lock)
 62__acquires(mtu->lock)
 63{
 64	int ret;
 65
 66	if (!mtu->gadget_driver)
 67		return -EOPNOTSUPP;
 68
 69	spin_unlock(&mtu->lock);
 70	ret = mtu->gadget_driver->setup(&mtu->g, setup);
 71	spin_lock(&mtu->lock);
 72
 73	dev_dbg(mtu->dev, "%s ret %d\n", __func__, ret);
 74	return ret;
 75}
 76
 77static void ep0_write_fifo(struct mtu3_ep *mep, const u8 *src, u16 len)
 78{
 79	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
 80	u16 index = 0;
 81
 82	dev_dbg(mep->mtu->dev, "%s: ep%din, len=%d, buf=%p\n",
 83		__func__, mep->epnum, len, src);
 84
 85	if (len >= 4) {
 86		iowrite32_rep(fifo, src, len >> 2);
 87		index = len & ~0x03;
 88	}
 89	if (len & 0x02) {
 90		writew(*(u16 *)&src[index], fifo);
 91		index += 2;
 92	}
 93	if (len & 0x01)
 94		writeb(src[index], fifo);
 95}
 96
 97static void ep0_read_fifo(struct mtu3_ep *mep, u8 *dst, u16 len)
 98{
 99	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
100	u32 value;
101	u16 index = 0;
102
103	dev_dbg(mep->mtu->dev, "%s: ep%dout len=%d buf=%p\n",
104		 __func__, mep->epnum, len, dst);
105
106	if (len >= 4) {
107		ioread32_rep(fifo, dst, len >> 2);
108		index = len & ~0x03;
109	}
110	if (len & 0x3) {
111		value = readl(fifo);
112		memcpy(&dst[index], &value, len & 0x3);
113	}
114
115}
116
117static void ep0_load_test_packet(struct mtu3 *mtu)
118{
119	/*
120	 * because the length of test packet is less than max packet of HS ep0,
121	 * write it into fifo directly.
122	 */
123	ep0_write_fifo(mtu->ep0, mtu3_test_packet, sizeof(mtu3_test_packet));
124}
125
126/*
127 * A. send STALL for setup transfer without data stage:
128 *		set SENDSTALL and SETUPPKTRDY at the same time;
129 * B. send STALL for other cases:
130 *		set SENDSTALL only.
131 */
132static void ep0_stall_set(struct mtu3_ep *mep0, bool set, u32 pktrdy)
133{
134	struct mtu3 *mtu = mep0->mtu;
135	void __iomem *mbase = mtu->mac_base;
136	u32 csr;
137
138	/* EP0_SENTSTALL is W1C */
139	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
140	if (set)
141		csr |= EP0_SENDSTALL | pktrdy;
142	else
143		csr = (csr & ~EP0_SENDSTALL) | EP0_SENTSTALL;
144	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
145
146	mtu->delayed_status = false;
147	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
148
149	dev_dbg(mtu->dev, "ep0: %s STALL, ep0_state: %s\n",
150		set ? "SEND" : "CLEAR", decode_ep0_state(mtu));
151}
152
153static int ep0_queue(struct mtu3_ep *mep0, struct mtu3_request *mreq);
154
155static void ep0_dummy_complete(struct usb_ep *ep, struct usb_request *req)
156{}
157
158static void ep0_set_sel_complete(struct usb_ep *ep, struct usb_request *req)
159{
160	struct mtu3_request *mreq;
161	struct mtu3 *mtu;
162	struct usb_set_sel_req sel;
163
164	memcpy(&sel, req->buf, sizeof(sel));
165
166	mreq = to_mtu3_request(req);
167	mtu = mreq->mtu;
168	dev_dbg(mtu->dev, "u1sel:%d, u1pel:%d, u2sel:%d, u2pel:%d\n",
169		sel.u1_sel, sel.u1_pel, sel.u2_sel, sel.u2_pel);
170}
171
172/* queue data stage to handle 6 byte SET_SEL request */
173static int ep0_set_sel(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
174{
175	int ret;
176	u16 length = le16_to_cpu(setup->wLength);
177
178	if (unlikely(length != 6)) {
179		dev_err(mtu->dev, "%s wrong wLength:%d\n",
180			__func__, length);
181		return -EINVAL;
182	}
183
184	mtu->ep0_req.mep = mtu->ep0;
185	mtu->ep0_req.request.length = 6;
186	mtu->ep0_req.request.buf = mtu->setup_buf;
187	mtu->ep0_req.request.complete = ep0_set_sel_complete;
188	ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
189
190	return ret < 0 ? ret : 1;
191}
192
193static int
194ep0_get_status(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
195{
196	struct mtu3_ep *mep = NULL;
197	int handled = 1;
198	u8 result[2] = {0, 0};
199	u8 epnum = 0;
200	int is_in;
201
202	switch (setup->bRequestType & USB_RECIP_MASK) {
203	case USB_RECIP_DEVICE:
204		result[0] = mtu->is_self_powered << USB_DEVICE_SELF_POWERED;
205		result[0] |= mtu->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
206
207		if (mtu->g.speed >= USB_SPEED_SUPER) {
208			result[0] |= mtu->u1_enable << USB_DEV_STAT_U1_ENABLED;
209			result[0] |= mtu->u2_enable << USB_DEV_STAT_U2_ENABLED;
210		}
211
212		dev_dbg(mtu->dev, "%s result=%x, U1=%x, U2=%x\n", __func__,
213			result[0], mtu->u1_enable, mtu->u2_enable);
214
215		break;
216	case USB_RECIP_INTERFACE:
217		break;
218	case USB_RECIP_ENDPOINT:
219		epnum = (u8) le16_to_cpu(setup->wIndex);
220		is_in = epnum & USB_DIR_IN;
221		epnum &= USB_ENDPOINT_NUMBER_MASK;
222
223		if (epnum >= mtu->num_eps) {
224			handled = -EINVAL;
225			break;
226		}
227		if (!epnum)
228			break;
229
230		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
231		if (!mep->desc) {
232			handled = -EINVAL;
233			break;
234		}
235		if (mep->flags & MTU3_EP_STALL)
236			result[0] |= 1 << USB_ENDPOINT_HALT;
237
238		break;
239	default:
240		/* class, vendor, etc ... delegate */
241		handled = 0;
242		break;
243	}
244
245	if (handled > 0) {
246		int ret;
247
248		/* prepare a data stage for GET_STATUS */
249		dev_dbg(mtu->dev, "get_status=%x\n", *(u16 *)result);
250		memcpy(mtu->setup_buf, result, sizeof(result));
251		mtu->ep0_req.mep = mtu->ep0;
252		mtu->ep0_req.request.length = 2;
253		mtu->ep0_req.request.buf = &mtu->setup_buf;
254		mtu->ep0_req.request.complete = ep0_dummy_complete;
255		ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
256		if (ret < 0)
257			handled = ret;
258	}
259	return handled;
260}
261
262static int handle_test_mode(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
263{
264	void __iomem *mbase = mtu->mac_base;
265	int handled = 1;
266
267	switch (le16_to_cpu(setup->wIndex) >> 8) {
268	case TEST_J:
269		dev_dbg(mtu->dev, "TEST_J\n");
270		mtu->test_mode_nr = TEST_J_MODE;
271		break;
272	case TEST_K:
273		dev_dbg(mtu->dev, "TEST_K\n");
274		mtu->test_mode_nr = TEST_K_MODE;
275		break;
276	case TEST_SE0_NAK:
277		dev_dbg(mtu->dev, "TEST_SE0_NAK\n");
278		mtu->test_mode_nr = TEST_SE0_NAK_MODE;
279		break;
280	case TEST_PACKET:
281		dev_dbg(mtu->dev, "TEST_PACKET\n");
282		mtu->test_mode_nr = TEST_PACKET_MODE;
283		break;
284	default:
285		handled = -EINVAL;
286		goto out;
287	}
288
289	mtu->test_mode = true;
290
291	/* no TX completion interrupt, and need restart platform after test */
292	if (mtu->test_mode_nr == TEST_PACKET_MODE)
293		ep0_load_test_packet(mtu);
294
295	mtu3_writel(mbase, U3D_USB2_TEST_MODE, mtu->test_mode_nr);
296
297	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
298
299out:
300	return handled;
301}
302
303static int ep0_handle_feature_dev(struct mtu3 *mtu,
304		struct usb_ctrlrequest *setup, bool set)
305{
306	void __iomem *mbase = mtu->mac_base;
307	int handled = -EINVAL;
308	u32 lpc;
309
310	switch (le16_to_cpu(setup->wValue)) {
311	case USB_DEVICE_REMOTE_WAKEUP:
312		mtu->may_wakeup = !!set;
313		handled = 1;
314		break;
315	case USB_DEVICE_TEST_MODE:
316		if (!set || (mtu->g.speed != USB_SPEED_HIGH) ||
317			(le16_to_cpu(setup->wIndex) & 0xff))
318			break;
319
320		handled = handle_test_mode(mtu, setup);
321		break;
322	case USB_DEVICE_U1_ENABLE:
323		if (mtu->g.speed < USB_SPEED_SUPER ||
324		    mtu->g.state != USB_STATE_CONFIGURED)
325			break;
326
327		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
328		if (set)
329			lpc |= SW_U1_ACCEPT_ENABLE;
330		else
331			lpc &= ~SW_U1_ACCEPT_ENABLE;
332		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
333
334		mtu->u1_enable = !!set;
335		handled = 1;
336		break;
337	case USB_DEVICE_U2_ENABLE:
338		if (mtu->g.speed < USB_SPEED_SUPER ||
339		    mtu->g.state != USB_STATE_CONFIGURED)
340			break;
341
342		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
343		if (set)
344			lpc |= SW_U2_ACCEPT_ENABLE;
345		else
346			lpc &= ~SW_U2_ACCEPT_ENABLE;
347		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
348
349		mtu->u2_enable = !!set;
350		handled = 1;
351		break;
352	default:
353		handled = -EINVAL;
354		break;
355	}
356	return handled;
357}
358
359static int ep0_handle_feature(struct mtu3 *mtu,
360		struct usb_ctrlrequest *setup, bool set)
361{
362	struct mtu3_ep *mep;
363	int handled = -EINVAL;
364	int is_in;
365	u16 value;
366	u16 index;
367	u8 epnum;
368
369	value = le16_to_cpu(setup->wValue);
370	index = le16_to_cpu(setup->wIndex);
371
372	switch (setup->bRequestType & USB_RECIP_MASK) {
373	case USB_RECIP_DEVICE:
374		handled = ep0_handle_feature_dev(mtu, setup, set);
375		break;
376	case USB_RECIP_INTERFACE:
377		/* superspeed only */
378		if (value == USB_INTRF_FUNC_SUSPEND &&
379		    mtu->g.speed >= USB_SPEED_SUPER) {
380			/*
381			 * forward the request because function drivers
382			 * should handle it
383			 */
384			handled = 0;
385		}
386		break;
387	case USB_RECIP_ENDPOINT:
388		epnum = index & USB_ENDPOINT_NUMBER_MASK;
389		if (epnum == 0 || epnum >= mtu->num_eps ||
390			value != USB_ENDPOINT_HALT)
391			break;
392
393		is_in = index & USB_DIR_IN;
394		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
395		if (!mep->desc)
396			break;
397
398		handled = 1;
399		/* ignore request if endpoint is wedged */
400		if (mep->wedged)
401			break;
402
403		mtu3_ep_stall_set(mep, set);
404		break;
405	default:
406		/* class, vendor, etc ... delegate */
407		handled = 0;
408		break;
409	}
410	return handled;
411}
412
413/*
414 * handle all control requests can be handled
415 * returns:
416 *	negative errno - error happened
417 *	zero - need delegate SETUP to gadget driver
418 *	positive - already handled
419 */
420static int handle_standard_request(struct mtu3 *mtu,
421			  struct usb_ctrlrequest *setup)
422{
423	void __iomem *mbase = mtu->mac_base;
424	enum usb_device_state state = mtu->g.state;
425	int handled = -EINVAL;
426	u32 dev_conf;
427	u16 value;
428
429	value = le16_to_cpu(setup->wValue);
430
431	/* the gadget driver handles everything except what we must handle */
432	switch (setup->bRequest) {
433	case USB_REQ_SET_ADDRESS:
434		/* change it after the status stage */
435		mtu->address = (u8) (value & 0x7f);
436		dev_dbg(mtu->dev, "set address to 0x%x\n", mtu->address);
437
438		dev_conf = mtu3_readl(mbase, U3D_DEVICE_CONF);
439		dev_conf &= ~DEV_ADDR_MSK;
440		dev_conf |= DEV_ADDR(mtu->address);
441		mtu3_writel(mbase, U3D_DEVICE_CONF, dev_conf);
442
443		if (mtu->address)
444			usb_gadget_set_state(&mtu->g, USB_STATE_ADDRESS);
445		else
446			usb_gadget_set_state(&mtu->g, USB_STATE_DEFAULT);
447
448		handled = 1;
449		break;
450	case USB_REQ_SET_CONFIGURATION:
451		if (state == USB_STATE_ADDRESS) {
452			usb_gadget_set_state(&mtu->g,
453					USB_STATE_CONFIGURED);
454		} else if (state == USB_STATE_CONFIGURED) {
455			/*
456			 * USB2 spec sec 9.4.7, if wValue is 0 then dev
457			 * is moved to addressed state
458			 */
459			if (!value)
460				usb_gadget_set_state(&mtu->g,
461						USB_STATE_ADDRESS);
462		}
463		handled = 0;
464		break;
465	case USB_REQ_CLEAR_FEATURE:
466		handled = ep0_handle_feature(mtu, setup, 0);
467		break;
468	case USB_REQ_SET_FEATURE:
469		handled = ep0_handle_feature(mtu, setup, 1);
470		break;
471	case USB_REQ_GET_STATUS:
472		handled = ep0_get_status(mtu, setup);
473		break;
474	case USB_REQ_SET_SEL:
475		handled = ep0_set_sel(mtu, setup);
476		break;
477	case USB_REQ_SET_ISOCH_DELAY:
478		handled = 1;
479		break;
480	default:
481		/* delegate SET_CONFIGURATION, etc */
482		handled = 0;
483	}
484
485	return handled;
486}
487
488/* receive an data packet (OUT) */
489static void ep0_rx_state(struct mtu3 *mtu)
490{
491	struct mtu3_request *mreq;
492	struct usb_request *req;
493	void __iomem *mbase = mtu->mac_base;
494	u32 maxp;
495	u32 csr;
496	u16 count = 0;
497
498	dev_dbg(mtu->dev, "%s\n", __func__);
499
500	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
501	mreq = next_ep0_request(mtu);
502	req = &mreq->request;
503
504	/* read packet and ack; or stall because of gadget driver bug */
505	if (req) {
506		void *buf = req->buf + req->actual;
507		unsigned int len = req->length - req->actual;
508
509		/* read the buffer */
510		count = mtu3_readl(mbase, U3D_RXCOUNT0);
511		if (count > len) {
512			req->status = -EOVERFLOW;
513			count = len;
514		}
515		ep0_read_fifo(mtu->ep0, buf, count);
516		req->actual += count;
517		csr |= EP0_RXPKTRDY;
518
519		maxp = mtu->g.ep0->maxpacket;
520		if (count < maxp || req->actual == req->length) {
521			mtu->ep0_state = MU3D_EP0_STATE_SETUP;
522			dev_dbg(mtu->dev, "ep0 state: %s\n",
523				decode_ep0_state(mtu));
524
525			csr |= EP0_DATAEND;
526		} else {
527			req = NULL;
528		}
529	} else {
530		csr |= EP0_RXPKTRDY | EP0_SENDSTALL;
531		dev_dbg(mtu->dev, "%s: SENDSTALL\n", __func__);
532	}
533
534	mtu3_writel(mbase, U3D_EP0CSR, csr);
535
536	/* give back the request if have received all data */
537	if (req)
538		ep0_req_giveback(mtu, req);
539
540}
541
542/* transmitting to the host (IN) */
543static void ep0_tx_state(struct mtu3 *mtu)
544{
545	struct mtu3_request *mreq = next_ep0_request(mtu);
546	struct usb_request *req;
547	u32 csr;
548	u8 *src;
549	u8 count;
550	u32 maxp;
551
552	dev_dbg(mtu->dev, "%s\n", __func__);
553
554	if (!mreq)
555		return;
556
557	maxp = mtu->g.ep0->maxpacket;
558	req = &mreq->request;
559
560	/* load the data */
561	src = (u8 *)req->buf + req->actual;
562	count = min(maxp, req->length - req->actual);
563	if (count)
564		ep0_write_fifo(mtu->ep0, src, count);
565
566	dev_dbg(mtu->dev, "%s act=%d, len=%d, cnt=%d, maxp=%d zero=%d\n",
567		 __func__, req->actual, req->length, count, maxp, req->zero);
568
569	req->actual += count;
570
571	if ((count < maxp)
572		|| ((req->actual == req->length) && !req->zero))
573		mtu->ep0_state = MU3D_EP0_STATE_TX_END;
574
575	/* send it out, triggering a "txpktrdy cleared" irq */
576	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
577	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr | EP0_TXPKTRDY);
578
579	dev_dbg(mtu->dev, "%s ep0csr=0x%x\n", __func__,
580		mtu3_readl(mtu->mac_base, U3D_EP0CSR));
581}
582
583static void ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
584{
585	struct mtu3_request *mreq;
586	u32 count;
587	u32 csr;
588
589	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
590	count = mtu3_readl(mtu->mac_base, U3D_RXCOUNT0);
591
592	ep0_read_fifo(mtu->ep0, (u8 *)setup, count);
593
594	dev_dbg(mtu->dev, "SETUP req%02x.%02x v%04x i%04x l%04x\n",
595		 setup->bRequestType, setup->bRequest,
596		 le16_to_cpu(setup->wValue), le16_to_cpu(setup->wIndex),
597		 le16_to_cpu(setup->wLength));
598
599	/* clean up any leftover transfers */
600	mreq = next_ep0_request(mtu);
601	if (mreq)
602		ep0_req_giveback(mtu, &mreq->request);
603
604	if (le16_to_cpu(setup->wLength) == 0) {
605		;	/* no data stage, nothing to do */
606	} else if (setup->bRequestType & USB_DIR_IN) {
607		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
608			csr | EP0_SETUPPKTRDY | EP0_DPHTX);
609		mtu->ep0_state = MU3D_EP0_STATE_TX;
610	} else {
611		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
612			(csr | EP0_SETUPPKTRDY) & (~EP0_DPHTX));
613		mtu->ep0_state = MU3D_EP0_STATE_RX;
614	}
615}
616
617static int ep0_handle_setup(struct mtu3 *mtu)
618__releases(mtu->lock)
619__acquires(mtu->lock)
620{
621	struct usb_ctrlrequest setup;
622	struct mtu3_request *mreq;
623	void __iomem *mbase = mtu->mac_base;
624	int handled = 0;
625
626	ep0_read_setup(mtu, &setup);
627
628	if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
629		handled = handle_standard_request(mtu, &setup);
630
631	dev_dbg(mtu->dev, "handled %d, ep0_state: %s\n",
632		 handled, decode_ep0_state(mtu));
633
634	if (handled < 0)
635		goto stall;
636	else if (handled > 0)
637		goto finish;
638
639	handled = forward_to_driver(mtu, &setup);
640	if (handled < 0) {
641stall:
642		dev_dbg(mtu->dev, "%s stall (%d)\n", __func__, handled);
643
644		ep0_stall_set(mtu->ep0, true,
645			le16_to_cpu(setup.wLength) ? 0 : EP0_SETUPPKTRDY);
646
647		return 0;
648	}
649
650finish:
651	if (mtu->test_mode) {
652		;	/* nothing to do */
653	} else if (handled == USB_GADGET_DELAYED_STATUS) {
654		/* handle the delay STATUS phase till receive ep_queue on ep0 */
655		mtu->delayed_status = true;
656	} else if (le16_to_cpu(setup.wLength) == 0) { /* no data stage */
657
658		mtu3_writel(mbase, U3D_EP0CSR,
659			(mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS)
660			| EP0_SETUPPKTRDY | EP0_DATAEND);
661
662		/* complete zlp request directly */
663		mreq = next_ep0_request(mtu);
664		if (mreq && !mreq->request.length)
665			ep0_req_giveback(mtu, &mreq->request);
666	}
667
668	return 0;
669}
670
671irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu)
672{
673	void __iomem *mbase = mtu->mac_base;
674	struct mtu3_request *mreq;
675	u32 int_status;
676	irqreturn_t ret = IRQ_NONE;
677	u32 csr;
678	u32 len;
679
680	int_status = mtu3_readl(mbase, U3D_EPISR);
681	int_status &= mtu3_readl(mbase, U3D_EPIER);
682	mtu3_writel(mbase, U3D_EPISR, int_status); /* W1C */
683
684	/* only handle ep0's */
685	if (!(int_status & EP0ISR))
686		return IRQ_NONE;
687
688	csr = mtu3_readl(mbase, U3D_EP0CSR);
689
690	dev_dbg(mtu->dev, "%s csr=0x%x\n", __func__, csr);
691
692	/* we sent a stall.. need to clear it now.. */
693	if (csr & EP0_SENTSTALL) {
694		ep0_stall_set(mtu->ep0, false, 0);
695		csr = mtu3_readl(mbase, U3D_EP0CSR);
696		ret = IRQ_HANDLED;
697	}
698	dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
699
700	switch (mtu->ep0_state) {
701	case MU3D_EP0_STATE_TX:
702		/* irq on clearing txpktrdy */
703		if ((csr & EP0_FIFOFULL) == 0) {
704			ep0_tx_state(mtu);
705			ret = IRQ_HANDLED;
706		}
707		break;
708	case MU3D_EP0_STATE_RX:
709		/* irq on set rxpktrdy */
710		if (csr & EP0_RXPKTRDY) {
711			ep0_rx_state(mtu);
712			ret = IRQ_HANDLED;
713		}
714		break;
715	case MU3D_EP0_STATE_TX_END:
716		mtu3_writel(mbase, U3D_EP0CSR,
717			(csr & EP0_W1C_BITS) | EP0_DATAEND);
718
719		mreq = next_ep0_request(mtu);
720		if (mreq)
721			ep0_req_giveback(mtu, &mreq->request);
722
723		mtu->ep0_state = MU3D_EP0_STATE_SETUP;
724		ret = IRQ_HANDLED;
725		dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
726		break;
727	case MU3D_EP0_STATE_SETUP:
728		if (!(csr & EP0_SETUPPKTRDY))
729			break;
730
731		len = mtu3_readl(mbase, U3D_RXCOUNT0);
732		if (len != 8) {
733			dev_err(mtu->dev, "SETUP packet len %d != 8 ?\n", len);
734			break;
735		}
736
737		ep0_handle_setup(mtu);
738		ret = IRQ_HANDLED;
739		break;
740	default:
741		/* can't happen */
742		ep0_stall_set(mtu->ep0, true, 0);
743		WARN_ON(1);
744		break;
745	}
746
747	return ret;
748}
749
750
751static int mtu3_ep0_enable(struct usb_ep *ep,
752	const struct usb_endpoint_descriptor *desc)
753{
754	/* always enabled */
755	return -EINVAL;
756}
757
758static int mtu3_ep0_disable(struct usb_ep *ep)
759{
760	/* always enabled */
761	return -EINVAL;
762}
763
764static int ep0_queue(struct mtu3_ep *mep, struct mtu3_request *mreq)
765{
766	struct mtu3 *mtu = mep->mtu;
767
768	mreq->mtu = mtu;
769	mreq->request.actual = 0;
770	mreq->request.status = -EINPROGRESS;
771
772	dev_dbg(mtu->dev, "%s %s (ep0_state: %s), len#%d\n", __func__,
773		mep->name, decode_ep0_state(mtu), mreq->request.length);
774
775	switch (mtu->ep0_state) {
776	case MU3D_EP0_STATE_SETUP:
777	case MU3D_EP0_STATE_RX:	/* control-OUT data */
778	case MU3D_EP0_STATE_TX:	/* control-IN data */
779		break;
780	default:
781		dev_err(mtu->dev, "%s, error in ep0 state %s\n", __func__,
782			decode_ep0_state(mtu));
783		return -EINVAL;
784	}
785
786	if (mtu->delayed_status) {
787		u32 csr;
788
789		mtu->delayed_status = false;
790		csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
791		csr |= EP0_SETUPPKTRDY | EP0_DATAEND;
792		mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
793		/* needn't giveback the request for handling delay STATUS */
794		return 0;
795	}
796
797	if (!list_empty(&mep->req_list))
798		return -EBUSY;
799
800	list_add_tail(&mreq->list, &mep->req_list);
801
802	/* sequence #1, IN ... start writing the data */
803	if (mtu->ep0_state == MU3D_EP0_STATE_TX)
804		ep0_tx_state(mtu);
805
806	return 0;
807}
808
809static int mtu3_ep0_queue(struct usb_ep *ep,
810	struct usb_request *req, gfp_t gfp)
811{
812	struct mtu3_ep *mep;
813	struct mtu3_request *mreq;
814	struct mtu3 *mtu;
815	unsigned long flags;
816	int ret = 0;
817
818	if (!ep || !req)
819		return -EINVAL;
820
821	mep = to_mtu3_ep(ep);
822	mtu = mep->mtu;
823	mreq = to_mtu3_request(req);
824
825	spin_lock_irqsave(&mtu->lock, flags);
826	ret = ep0_queue(mep, mreq);
827	spin_unlock_irqrestore(&mtu->lock, flags);
828	return ret;
829}
830
831static int mtu3_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
832{
833	/* we just won't support this */
834	return -EINVAL;
835}
836
837static int mtu3_ep0_halt(struct usb_ep *ep, int value)
838{
839	struct mtu3_ep *mep;
840	struct mtu3 *mtu;
841	unsigned long flags;
842	int ret = 0;
843
844	if (!ep || !value)
845		return -EINVAL;
846
847	mep = to_mtu3_ep(ep);
848	mtu = mep->mtu;
849
850	dev_dbg(mtu->dev, "%s\n", __func__);
851
852	spin_lock_irqsave(&mtu->lock, flags);
853
854	if (!list_empty(&mep->req_list)) {
855		ret = -EBUSY;
856		goto cleanup;
857	}
858
859	switch (mtu->ep0_state) {
860	/*
861	 * stalls are usually issued after parsing SETUP packet, either
862	 * directly in irq context from setup() or else later.
863	 */
864	case MU3D_EP0_STATE_TX:
865	case MU3D_EP0_STATE_TX_END:
866	case MU3D_EP0_STATE_RX:
867	case MU3D_EP0_STATE_SETUP:
868		ep0_stall_set(mtu->ep0, true, 0);
869		break;
870	default:
871		dev_dbg(mtu->dev, "ep0 can't halt in state %s\n",
872			decode_ep0_state(mtu));
873		ret = -EINVAL;
874	}
875
876cleanup:
877	spin_unlock_irqrestore(&mtu->lock, flags);
878	return ret;
879}
880
881const struct usb_ep_ops mtu3_ep0_ops = {
882	.enable = mtu3_ep0_enable,
883	.disable = mtu3_ep0_disable,
884	.alloc_request = mtu3_alloc_request,
885	.free_request = mtu3_free_request,
886	.queue = mtu3_ep0_queue,
887	.dequeue = mtu3_ep0_dequeue,
888	.set_halt = mtu3_ep0_halt,
889};