1/*
2 * core_intr.c - DesignWare HS OTG Controller common interrupt handling
3 *
4 * Copyright (C) 2004-2013 Synopsys, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions, and the following disclaimer,
11 *    without modification.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The names of the above-listed copyright holders may not be used
16 *    to endorse or promote products derived from this software without
17 *    specific prior written permission.
18 *
19 * ALTERNATIVELY, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") as published by the Free Software
21 * Foundation; either version 2 of the License, or (at your option) any
22 * later version.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
25 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
26 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
28 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37/*
38 * This file contains the common interrupt handlers
39 */
40#include <linux/kernel.h>
41#include <linux/module.h>
42#include <linux/moduleparam.h>
43#include <linux/spinlock.h>
44#include <linux/interrupt.h>
45#include <linux/dma-mapping.h>
46#include <linux/io.h>
47#include <linux/slab.h>
48#include <linux/usb.h>
49
50#include <linux/usb/hcd.h>
51#include <linux/usb/ch11.h>
52
53#include "core.h"
54#include "hcd.h"
55
56static const char *dwc2_op_state_str(struct dwc2_hsotg *hsotg)
57{
58	switch (hsotg->op_state) {
59	case OTG_STATE_A_HOST:
60		return "a_host";
61	case OTG_STATE_A_SUSPEND:
62		return "a_suspend";
63	case OTG_STATE_A_PERIPHERAL:
64		return "a_peripheral";
65	case OTG_STATE_B_PERIPHERAL:
66		return "b_peripheral";
67	case OTG_STATE_B_HOST:
68		return "b_host";
69	default:
70		return "unknown";
71	}
72}
73
74/**
75 * dwc2_handle_usb_port_intr - handles OTG PRTINT interrupts.
76 * When the PRTINT interrupt fires, there are certain status bits in the Host
77 * Port that needs to get cleared.
78 *
79 * @hsotg: Programming view of DWC_otg controller
80 */
81static void dwc2_handle_usb_port_intr(struct dwc2_hsotg *hsotg)
82{
83	u32 hprt0 = dwc2_readl(hsotg->regs + HPRT0);
84
85	if (hprt0 & HPRT0_ENACHG) {
86		hprt0 &= ~HPRT0_ENA;
87		dwc2_writel(hprt0, hsotg->regs + HPRT0);
88	}
89
90	/* Clear interrupt */
91	dwc2_writel(GINTSTS_PRTINT, hsotg->regs + GINTSTS);
92}
93
94/**
95 * dwc2_handle_mode_mismatch_intr() - Logs a mode mismatch warning message
96 *
97 * @hsotg: Programming view of DWC_otg controller
98 */
99static void dwc2_handle_mode_mismatch_intr(struct dwc2_hsotg *hsotg)
100{
101	dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
102		 dwc2_is_host_mode(hsotg) ? "Host" : "Device");
103
104	/* Clear interrupt */
105	dwc2_writel(GINTSTS_MODEMIS, hsotg->regs + GINTSTS);
106}
107
108/**
109 * dwc2_handle_otg_intr() - Handles the OTG Interrupts. It reads the OTG
110 * Interrupt Register (GOTGINT) to determine what interrupt has occurred.
111 *
112 * @hsotg: Programming view of DWC_otg controller
113 */
114static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg)
115{
116	u32 gotgint;
117	u32 gotgctl;
118	u32 gintmsk;
119
120	gotgint = dwc2_readl(hsotg->regs + GOTGINT);
121	gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
122	dev_dbg(hsotg->dev, "++OTG Interrupt gotgint=%0x [%s]\n", gotgint,
123		dwc2_op_state_str(hsotg));
124
125	if (gotgint & GOTGINT_SES_END_DET) {
126		dev_dbg(hsotg->dev,
127			" ++OTG Interrupt: Session End Detected++ (%s)\n",
128			dwc2_op_state_str(hsotg));
129		gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
130
131		if (dwc2_is_device_mode(hsotg))
132			dwc2_hsotg_disconnect(hsotg);
133
134		if (hsotg->op_state == OTG_STATE_B_HOST) {
135			hsotg->op_state = OTG_STATE_B_PERIPHERAL;
136		} else {
137			/*
138			 * If not B_HOST and Device HNP still set, HNP did
139			 * not succeed!
140			 */
141			if (gotgctl & GOTGCTL_DEVHNPEN) {
142				dev_dbg(hsotg->dev, "Session End Detected\n");
143				dev_err(hsotg->dev,
144					"Device Not Connected/Responding!\n");
145			}
146
147			/*
148			 * If Session End Detected the B-Cable has been
149			 * disconnected
150			 */
151			/* Reset to a clean state */
152			hsotg->lx_state = DWC2_L0;
153		}
154
155		gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
156		gotgctl &= ~GOTGCTL_DEVHNPEN;
157		dwc2_writel(gotgctl, hsotg->regs + GOTGCTL);
158	}
159
160	if (gotgint & GOTGINT_SES_REQ_SUC_STS_CHNG) {
161		dev_dbg(hsotg->dev,
162			" ++OTG Interrupt: Session Request Success Status Change++\n");
163		gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
164		if (gotgctl & GOTGCTL_SESREQSCS) {
165			if (hsotg->core_params->phy_type ==
166					DWC2_PHY_TYPE_PARAM_FS
167			    && hsotg->core_params->i2c_enable > 0) {
168				hsotg->srp_success = 1;
169			} else {
170				/* Clear Session Request */
171				gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
172				gotgctl &= ~GOTGCTL_SESREQ;
173				dwc2_writel(gotgctl, hsotg->regs + GOTGCTL);
174			}
175		}
176	}
177
178	if (gotgint & GOTGINT_HST_NEG_SUC_STS_CHNG) {
179		/*
180		 * Print statements during the HNP interrupt handling
181		 * can cause it to fail
182		 */
183		gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
184		/*
185		 * WA for 3.00a- HW is not setting cur_mode, even sometimes
186		 * this does not help
187		 */
188		if (hsotg->hw_params.snpsid >= DWC2_CORE_REV_3_00a)
189			udelay(100);
190		if (gotgctl & GOTGCTL_HSTNEGSCS) {
191			if (dwc2_is_host_mode(hsotg)) {
192				hsotg->op_state = OTG_STATE_B_HOST;
193				/*
194				 * Need to disable SOF interrupt immediately.
195				 * When switching from device to host, the PCD
196				 * interrupt handler won't handle the interrupt
197				 * if host mode is already set. The HCD
198				 * interrupt handler won't get called if the
199				 * HCD state is HALT. This means that the
200				 * interrupt does not get handled and Linux
201				 * complains loudly.
202				 */
203				gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
204				gintmsk &= ~GINTSTS_SOF;
205				dwc2_writel(gintmsk, hsotg->regs + GINTMSK);
206
207				/*
208				 * Call callback function with spin lock
209				 * released
210				 */
211				spin_unlock(&hsotg->lock);
212
213				/* Initialize the Core for Host mode */
214				dwc2_hcd_start(hsotg);
215				spin_lock(&hsotg->lock);
216				hsotg->op_state = OTG_STATE_B_HOST;
217			}
218		} else {
219			gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
220			gotgctl &= ~(GOTGCTL_HNPREQ | GOTGCTL_DEVHNPEN);
221			dwc2_writel(gotgctl, hsotg->regs + GOTGCTL);
222			dev_dbg(hsotg->dev, "HNP Failed\n");
223			dev_err(hsotg->dev,
224				"Device Not Connected/Responding\n");
225		}
226	}
227
228	if (gotgint & GOTGINT_HST_NEG_DET) {
229		/*
230		 * The disconnect interrupt is set at the same time as
231		 * Host Negotiation Detected. During the mode switch all
232		 * interrupts are cleared so the disconnect interrupt
233		 * handler will not get executed.
234		 */
235		dev_dbg(hsotg->dev,
236			" ++OTG Interrupt: Host Negotiation Detected++ (%s)\n",
237			(dwc2_is_host_mode(hsotg) ? "Host" : "Device"));
238		if (dwc2_is_device_mode(hsotg)) {
239			dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n",
240				hsotg->op_state);
241			spin_unlock(&hsotg->lock);
242			dwc2_hcd_disconnect(hsotg);
243			spin_lock(&hsotg->lock);
244			hsotg->op_state = OTG_STATE_A_PERIPHERAL;
245		} else {
246			/* Need to disable SOF interrupt immediately */
247			gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
248			gintmsk &= ~GINTSTS_SOF;
249			dwc2_writel(gintmsk, hsotg->regs + GINTMSK);
250			spin_unlock(&hsotg->lock);
251			dwc2_hcd_start(hsotg);
252			spin_lock(&hsotg->lock);
253			hsotg->op_state = OTG_STATE_A_HOST;
254		}
255	}
256
257	if (gotgint & GOTGINT_A_DEV_TOUT_CHG)
258		dev_dbg(hsotg->dev,
259			" ++OTG Interrupt: A-Device Timeout Change++\n");
260	if (gotgint & GOTGINT_DBNCE_DONE)
261		dev_dbg(hsotg->dev, " ++OTG Interrupt: Debounce Done++\n");
262
263	/* Clear GOTGINT */
264	dwc2_writel(gotgint, hsotg->regs + GOTGINT);
265}
266
267/**
268 * dwc2_handle_conn_id_status_change_intr() - Handles the Connector ID Status
269 * Change Interrupt
270 *
271 * @hsotg: Programming view of DWC_otg controller
272 *
273 * Reads the OTG Interrupt Register (GOTCTL) to determine whether this is a
274 * Device to Host Mode transition or a Host to Device Mode transition. This only
275 * occurs when the cable is connected/removed from the PHY connector.
276 */
277static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
278{
279	u32 gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
280
281	/* Need to disable SOF interrupt immediately */
282	gintmsk &= ~GINTSTS_SOF;
283	dwc2_writel(gintmsk, hsotg->regs + GINTMSK);
284
285	dev_dbg(hsotg->dev, " ++Connector ID Status Change Interrupt++  (%s)\n",
286		dwc2_is_host_mode(hsotg) ? "Host" : "Device");
287
288	/*
289	 * Need to schedule a work, as there are possible DELAY function calls.
290	 * Release lock before scheduling workq as it holds spinlock during
291	 * scheduling.
292	 */
293	if (hsotg->wq_otg) {
294		spin_unlock(&hsotg->lock);
295		queue_work(hsotg->wq_otg, &hsotg->wf_otg);
296		spin_lock(&hsotg->lock);
297	}
298
299	/* Clear interrupt */
300	dwc2_writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
301}
302
303/**
304 * dwc2_handle_session_req_intr() - This interrupt indicates that a device is
305 * initiating the Session Request Protocol to request the host to turn on bus
306 * power so a new session can begin
307 *
308 * @hsotg: Programming view of DWC_otg controller
309 *
310 * This handler responds by turning on bus power. If the DWC_otg controller is
311 * in low power mode, this handler brings the controller out of low power mode
312 * before turning on bus power.
313 */
314static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
315{
316	int ret;
317
318	dev_dbg(hsotg->dev, "Session request interrupt - lx_state=%d\n",
319							hsotg->lx_state);
320
321	/* Clear interrupt */
322	dwc2_writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);
323
324	if (dwc2_is_device_mode(hsotg)) {
325		if (hsotg->lx_state == DWC2_L2) {
326			ret = dwc2_exit_hibernation(hsotg, true);
327			if (ret && (ret != -ENOTSUPP))
328				dev_err(hsotg->dev,
329					"exit hibernation failed\n");
330		}
331
332		/*
333		 * Report disconnect if there is any previous session
334		 * established
335		 */
336		dwc2_hsotg_disconnect(hsotg);
337	}
338}
339
340/*
341 * This interrupt indicates that the DWC_otg controller has detected a
342 * resume or remote wakeup sequence. If the DWC_otg controller is in
343 * low power mode, the handler must brings the controller out of low
344 * power mode. The controller automatically begins resume signaling.
345 * The handler schedules a time to stop resume signaling.
346 */
347static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
348{
349	int ret;
350	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
351	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
352
353	if (dwc2_is_device_mode(hsotg)) {
354		dev_dbg(hsotg->dev, "DSTS=0x%0x\n",
355			dwc2_readl(hsotg->regs + DSTS));
356		if (hsotg->lx_state == DWC2_L2) {
357			u32 dctl = dwc2_readl(hsotg->regs + DCTL);
358
359			/* Clear Remote Wakeup Signaling */
360			dctl &= ~DCTL_RMTWKUPSIG;
361			dwc2_writel(dctl, hsotg->regs + DCTL);
362			ret = dwc2_exit_hibernation(hsotg, true);
363			if (ret && (ret != -ENOTSUPP))
364				dev_err(hsotg->dev, "exit hibernation failed\n");
365
366			call_gadget(hsotg, resume);
367		}
368		/* Change to L0 state */
369		hsotg->lx_state = DWC2_L0;
370	} else {
371		if (hsotg->core_params->hibernation) {
372			dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
373			return;
374		}
375		if (hsotg->lx_state != DWC2_L1) {
376			u32 pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
377
378			/* Restart the Phy Clock */
379			pcgcctl &= ~PCGCTL_STOPPCLK;
380			dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
381			mod_timer(&hsotg->wkp_timer,
382				  jiffies + msecs_to_jiffies(71));
383		} else {
384			/* Change to L0 state */
385			hsotg->lx_state = DWC2_L0;
386		}
387	}
388
389	/* Clear interrupt */
390	dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
391}
392
393/*
394 * This interrupt indicates that a device has been disconnected from the
395 * root port
396 */
397static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
398{
399	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
400		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
401		dwc2_op_state_str(hsotg));
402
403	if (hsotg->op_state == OTG_STATE_A_HOST)
404		dwc2_hcd_disconnect(hsotg);
405
406	dwc2_writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
407}
408
409/*
410 * This interrupt indicates that SUSPEND state has been detected on the USB.
411 *
412 * For HNP the USB Suspend interrupt signals the change from "a_peripheral"
413 * to "a_host".
414 *
415 * When power management is enabled the core will be put in low power mode.
416 */
417static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
418{
419	u32 dsts;
420	int ret;
421
422	dev_dbg(hsotg->dev, "USB SUSPEND\n");
423
424	if (dwc2_is_device_mode(hsotg)) {
425		/*
426		 * Check the Device status register to determine if the Suspend
427		 * state is active
428		 */
429		dsts = dwc2_readl(hsotg->regs + DSTS);
430		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", dsts);
431		dev_dbg(hsotg->dev,
432			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
433			!!(dsts & DSTS_SUSPSTS),
434			hsotg->hw_params.power_optimized);
435		if ((dsts & DSTS_SUSPSTS) && hsotg->hw_params.power_optimized) {
436			/* Ignore suspend request before enumeration */
437			if (!dwc2_is_device_connected(hsotg)) {
438				dev_dbg(hsotg->dev,
439						"ignore suspend request before enumeration\n");
440				goto clear_int;
441			}
442
443			ret = dwc2_enter_hibernation(hsotg);
444			if (ret) {
445				if (ret != -ENOTSUPP)
446					dev_err(hsotg->dev,
447							"enter hibernation failed\n");
448				goto skip_power_saving;
449			}
450
451			udelay(100);
452
453			/* Ask phy to be suspended */
454			if (!IS_ERR_OR_NULL(hsotg->uphy))
455				usb_phy_set_suspend(hsotg->uphy, true);
456skip_power_saving:
457			/*
458			 * Change to L2 (suspend) state before releasing
459			 * spinlock
460			 */
461			hsotg->lx_state = DWC2_L2;
462
463			/* Call gadget suspend callback */
464			call_gadget(hsotg, suspend);
465		}
466	} else {
467		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
468			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
469
470			/* Change to L2 (suspend) state */
471			hsotg->lx_state = DWC2_L2;
472			/* Clear the a_peripheral flag, back to a_host */
473			spin_unlock(&hsotg->lock);
474			dwc2_hcd_start(hsotg);
475			spin_lock(&hsotg->lock);
476			hsotg->op_state = OTG_STATE_A_HOST;
477		}
478	}
479
480clear_int:
481	/* Clear interrupt */
482	dwc2_writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
483}
484
485#define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
486			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
487			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
488			 GINTSTS_USBSUSP | GINTSTS_PRTINT)
489
490/*
491 * This function returns the Core Interrupt register
492 */
493static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
494{
495	u32 gintsts;
496	u32 gintmsk;
497	u32 gahbcfg;
498	u32 gintmsk_common = GINTMSK_COMMON;
499
500	gintsts = dwc2_readl(hsotg->regs + GINTSTS);
501	gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
502	gahbcfg = dwc2_readl(hsotg->regs + GAHBCFG);
503
504	/* If any common interrupts set */
505	if (gintsts & gintmsk_common)
506		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
507			gintsts, gintmsk);
508
509	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
510		return gintsts & gintmsk & gintmsk_common;
511	else
512		return 0;
513}
514
515/*
516 * Common interrupt handler
517 *
518 * The common interrupts are those that occur in both Host and Device mode.
519 * This handler handles the following interrupts:
520 * - Mode Mismatch Interrupt
521 * - OTG Interrupt
522 * - Connector ID Status Change Interrupt
523 * - Disconnect Interrupt
524 * - Session Request Interrupt
525 * - Resume / Remote Wakeup Detected Interrupt
526 * - Suspend Interrupt
527 */
528irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
529{
530	struct dwc2_hsotg *hsotg = dev;
531	u32 gintsts;
532	irqreturn_t retval = IRQ_NONE;
533
534	spin_lock(&hsotg->lock);
535
536	if (!dwc2_is_controller_alive(hsotg)) {
537		dev_warn(hsotg->dev, "Controller is dead\n");
538		goto out;
539	}
540
541	gintsts = dwc2_read_common_intr(hsotg);
542	if (gintsts & ~GINTSTS_PRTINT)
543		retval = IRQ_HANDLED;
544
545	if (gintsts & GINTSTS_MODEMIS)
546		dwc2_handle_mode_mismatch_intr(hsotg);
547	if (gintsts & GINTSTS_OTGINT)
548		dwc2_handle_otg_intr(hsotg);
549	if (gintsts & GINTSTS_CONIDSTSCHNG)
550		dwc2_handle_conn_id_status_change_intr(hsotg);
551	if (gintsts & GINTSTS_DISCONNINT)
552		dwc2_handle_disconnect_intr(hsotg);
553	if (gintsts & GINTSTS_SESSREQINT)
554		dwc2_handle_session_req_intr(hsotg);
555	if (gintsts & GINTSTS_WKUPINT)
556		dwc2_handle_wakeup_detected_intr(hsotg);
557	if (gintsts & GINTSTS_USBSUSP)
558		dwc2_handle_usb_suspend_intr(hsotg);
559
560	if (gintsts & GINTSTS_PRTINT) {
561		/*
562		 * The port interrupt occurs while in device mode with HPRT0
563		 * Port Enable/Disable
564		 */
565		if (dwc2_is_device_mode(hsotg)) {
566			dev_dbg(hsotg->dev,
567				" --Port interrupt received in Device mode--\n");
568			dwc2_handle_usb_port_intr(hsotg);
569			retval = IRQ_HANDLED;
570		}
571	}
572
573out:
574	spin_unlock(&hsotg->lock);
575	return retval;
576}
577