xref: /linux/drivers/usb/dwc2/core_intr.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2 /*
3  * core_intr.c - DesignWare HS OTG Controller common interrupt handling
4  *
5  * Copyright (C) 2004-2013 Synopsys, Inc.
6  */
7 
8 /*
9  * This file contains the common interrupt handlers
10  */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/spinlock.h>
15 #include <linux/interrupt.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/io.h>
18 #include <linux/slab.h>
19 #include <linux/usb.h>
20 
21 #include <linux/usb/hcd.h>
22 #include <linux/usb/ch11.h>
23 
24 #include "core.h"
25 #include "hcd.h"
26 
27 static const char *dwc2_op_state_str(struct dwc2_hsotg *hsotg)
28 {
29 	switch (hsotg->op_state) {
30 	case OTG_STATE_A_HOST:
31 		return "a_host";
32 	case OTG_STATE_A_SUSPEND:
33 		return "a_suspend";
34 	case OTG_STATE_A_PERIPHERAL:
35 		return "a_peripheral";
36 	case OTG_STATE_B_PERIPHERAL:
37 		return "b_peripheral";
38 	case OTG_STATE_B_HOST:
39 		return "b_host";
40 	default:
41 		return "unknown";
42 	}
43 }
44 
45 /**
46  * dwc2_handle_usb_port_intr - handles OTG PRTINT interrupts.
47  * When the PRTINT interrupt fires, there are certain status bits in the Host
48  * Port that needs to get cleared.
49  *
50  * @hsotg: Programming view of DWC_otg controller
51  */
52 static void dwc2_handle_usb_port_intr(struct dwc2_hsotg *hsotg)
53 {
54 	u32 hprt0 = dwc2_readl(hsotg, HPRT0);
55 
56 	if (hprt0 & HPRT0_ENACHG) {
57 		hprt0 &= ~HPRT0_ENA;
58 		dwc2_writel(hsotg, hprt0, HPRT0);
59 	}
60 }
61 
62 /**
63  * dwc2_handle_mode_mismatch_intr() - Logs a mode mismatch warning message
64  *
65  * @hsotg: Programming view of DWC_otg controller
66  */
67 static void dwc2_handle_mode_mismatch_intr(struct dwc2_hsotg *hsotg)
68 {
69 	/* Clear interrupt */
70 	dwc2_writel(hsotg, GINTSTS_MODEMIS, GINTSTS);
71 
72 	dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
73 		 dwc2_is_host_mode(hsotg) ? "Host" : "Device");
74 }
75 
76 /**
77  * dwc2_handle_otg_intr() - Handles the OTG Interrupts. It reads the OTG
78  * Interrupt Register (GOTGINT) to determine what interrupt has occurred.
79  *
80  * @hsotg: Programming view of DWC_otg controller
81  */
82 static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg)
83 {
84 	u32 gotgint;
85 	u32 gotgctl;
86 	u32 gintmsk;
87 	u32 pcgctl;
88 
89 	gotgint = dwc2_readl(hsotg, GOTGINT);
90 	gotgctl = dwc2_readl(hsotg, GOTGCTL);
91 	dev_dbg(hsotg->dev, "++OTG Interrupt gotgint=%0x [%s]\n", gotgint,
92 		dwc2_op_state_str(hsotg));
93 
94 	if (gotgint & GOTGINT_SES_END_DET) {
95 		dev_dbg(hsotg->dev,
96 			" ++OTG Interrupt: Session End Detected++ (%s)\n",
97 			dwc2_op_state_str(hsotg));
98 		gotgctl = dwc2_readl(hsotg, GOTGCTL);
99 
100 		if (dwc2_is_device_mode(hsotg)) {
101 			if (hsotg->params.eusb2_disc) {
102 				/* Clear the Gate hclk. */
103 				pcgctl = dwc2_readl(hsotg, PCGCTL);
104 				pcgctl &= ~PCGCTL_GATEHCLK;
105 				dwc2_writel(hsotg, pcgctl, PCGCTL);
106 				udelay(5);
107 
108 				/* Clear Phy Clock bit. */
109 				pcgctl = dwc2_readl(hsotg, PCGCTL);
110 				pcgctl &= ~PCGCTL_STOPPCLK;
111 				dwc2_writel(hsotg, pcgctl, PCGCTL);
112 				udelay(5);
113 			}
114 			dwc2_hsotg_disconnect(hsotg);
115 		}
116 
117 		if (hsotg->op_state == OTG_STATE_B_HOST) {
118 			hsotg->op_state = OTG_STATE_B_PERIPHERAL;
119 		} else {
120 			/*
121 			 * If not B_HOST and Device HNP still set, HNP did
122 			 * not succeed!
123 			 */
124 			if (gotgctl & GOTGCTL_DEVHNPEN) {
125 				dev_dbg(hsotg->dev, "Session End Detected\n");
126 				dev_err(hsotg->dev,
127 					"Device Not Connected/Responding!\n");
128 			}
129 
130 			/*
131 			 * If Session End Detected the B-Cable has been
132 			 * disconnected
133 			 */
134 			/* Reset to a clean state */
135 			hsotg->lx_state = DWC2_L3;
136 		}
137 
138 		gotgctl = dwc2_readl(hsotg, GOTGCTL);
139 		gotgctl &= ~GOTGCTL_DEVHNPEN;
140 		dwc2_writel(hsotg, gotgctl, GOTGCTL);
141 	}
142 
143 	if (gotgint & GOTGINT_SES_REQ_SUC_STS_CHNG) {
144 		dev_dbg(hsotg->dev,
145 			" ++OTG Interrupt: Session Request Success Status Change++\n");
146 		gotgctl = dwc2_readl(hsotg, GOTGCTL);
147 		if (gotgctl & GOTGCTL_SESREQSCS) {
148 			if (hsotg->params.phy_type == DWC2_PHY_TYPE_PARAM_FS &&
149 			    hsotg->params.i2c_enable) {
150 				hsotg->srp_success = 1;
151 			} else {
152 				/* Clear Session Request */
153 				gotgctl = dwc2_readl(hsotg, GOTGCTL);
154 				gotgctl &= ~GOTGCTL_SESREQ;
155 				dwc2_writel(hsotg, gotgctl, GOTGCTL);
156 			}
157 		}
158 	}
159 
160 	if (gotgint & GOTGINT_HST_NEG_SUC_STS_CHNG) {
161 		/*
162 		 * Print statements during the HNP interrupt handling
163 		 * can cause it to fail
164 		 */
165 		gotgctl = dwc2_readl(hsotg, GOTGCTL);
166 		/*
167 		 * WA for 3.00a- HW is not setting cur_mode, even sometimes
168 		 * this does not help
169 		 */
170 		if (hsotg->hw_params.snpsid >= DWC2_CORE_REV_3_00a)
171 			udelay(100);
172 		if (gotgctl & GOTGCTL_HSTNEGSCS) {
173 			if (dwc2_is_host_mode(hsotg)) {
174 				hsotg->op_state = OTG_STATE_B_HOST;
175 				/*
176 				 * Need to disable SOF interrupt immediately.
177 				 * When switching from device to host, the PCD
178 				 * interrupt handler won't handle the interrupt
179 				 * if host mode is already set. The HCD
180 				 * interrupt handler won't get called if the
181 				 * HCD state is HALT. This means that the
182 				 * interrupt does not get handled and Linux
183 				 * complains loudly.
184 				 */
185 				gintmsk = dwc2_readl(hsotg, GINTMSK);
186 				gintmsk &= ~GINTSTS_SOF;
187 				dwc2_writel(hsotg, gintmsk, GINTMSK);
188 
189 				/*
190 				 * Call callback function with spin lock
191 				 * released
192 				 */
193 				spin_unlock(&hsotg->lock);
194 
195 				/* Initialize the Core for Host mode */
196 				dwc2_hcd_start(hsotg);
197 				spin_lock(&hsotg->lock);
198 				hsotg->op_state = OTG_STATE_B_HOST;
199 			}
200 		} else {
201 			gotgctl = dwc2_readl(hsotg, GOTGCTL);
202 			gotgctl &= ~(GOTGCTL_HNPREQ | GOTGCTL_DEVHNPEN);
203 			dwc2_writel(hsotg, gotgctl, GOTGCTL);
204 			dev_dbg(hsotg->dev, "HNP Failed\n");
205 			dev_err(hsotg->dev,
206 				"Device Not Connected/Responding\n");
207 		}
208 	}
209 
210 	if (gotgint & GOTGINT_HST_NEG_DET) {
211 		/*
212 		 * The disconnect interrupt is set at the same time as
213 		 * Host Negotiation Detected. During the mode switch all
214 		 * interrupts are cleared so the disconnect interrupt
215 		 * handler will not get executed.
216 		 */
217 		dev_dbg(hsotg->dev,
218 			" ++OTG Interrupt: Host Negotiation Detected++ (%s)\n",
219 			(dwc2_is_host_mode(hsotg) ? "Host" : "Device"));
220 		if (dwc2_is_device_mode(hsotg)) {
221 			dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n",
222 				hsotg->op_state);
223 			spin_unlock(&hsotg->lock);
224 			dwc2_hcd_disconnect(hsotg, false);
225 			spin_lock(&hsotg->lock);
226 			hsotg->op_state = OTG_STATE_A_PERIPHERAL;
227 		} else {
228 			/* Need to disable SOF interrupt immediately */
229 			gintmsk = dwc2_readl(hsotg, GINTMSK);
230 			gintmsk &= ~GINTSTS_SOF;
231 			dwc2_writel(hsotg, gintmsk, GINTMSK);
232 			spin_unlock(&hsotg->lock);
233 			dwc2_hcd_start(hsotg);
234 			spin_lock(&hsotg->lock);
235 			hsotg->op_state = OTG_STATE_A_HOST;
236 		}
237 	}
238 
239 	if (gotgint & GOTGINT_A_DEV_TOUT_CHG)
240 		dev_dbg(hsotg->dev,
241 			" ++OTG Interrupt: A-Device Timeout Change++\n");
242 	if (gotgint & GOTGINT_DBNCE_DONE)
243 		dev_dbg(hsotg->dev, " ++OTG Interrupt: Debounce Done++\n");
244 
245 	/* Clear GOTGINT */
246 	dwc2_writel(hsotg, gotgint, GOTGINT);
247 }
248 
249 /**
250  * dwc2_handle_conn_id_status_change_intr() - Handles the Connector ID Status
251  * Change Interrupt
252  *
253  * @hsotg: Programming view of DWC_otg controller
254  *
255  * Reads the OTG Interrupt Register (GOTCTL) to determine whether this is a
256  * Device to Host Mode transition or a Host to Device Mode transition. This only
257  * occurs when the cable is connected/removed from the PHY connector.
258  */
259 static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
260 {
261 	u32 gintmsk;
262 
263 	/* Clear interrupt */
264 	dwc2_writel(hsotg, GINTSTS_CONIDSTSCHNG, GINTSTS);
265 
266 	/* Need to disable SOF interrupt immediately */
267 	gintmsk = dwc2_readl(hsotg, GINTMSK);
268 	gintmsk &= ~GINTSTS_SOF;
269 	dwc2_writel(hsotg, gintmsk, GINTMSK);
270 
271 	dev_dbg(hsotg->dev, " ++Connector ID Status Change Interrupt++  (%s)\n",
272 		dwc2_is_host_mode(hsotg) ? "Host" : "Device");
273 
274 	/*
275 	 * Need to schedule a work, as there are possible DELAY function calls.
276 	 */
277 	if (hsotg->wq_otg)
278 		queue_work(hsotg->wq_otg, &hsotg->wf_otg);
279 }
280 
281 /**
282  * dwc2_handle_session_req_intr() - This interrupt indicates that a device is
283  * initiating the Session Request Protocol to request the host to turn on bus
284  * power so a new session can begin
285  *
286  * @hsotg: Programming view of DWC_otg controller
287  *
288  * This handler responds by turning on bus power. If the DWC_otg controller is
289  * in low power mode, this handler brings the controller out of low power mode
290  * before turning on bus power.
291  */
292 static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
293 {
294 	int ret;
295 	u32 hprt0;
296 
297 	/* Clear interrupt */
298 	dwc2_writel(hsotg, GINTSTS_SESSREQINT, GINTSTS);
299 
300 	dev_dbg(hsotg->dev, "Session request interrupt - lx_state=%d\n",
301 		hsotg->lx_state);
302 
303 	if (dwc2_is_device_mode(hsotg)) {
304 		if (hsotg->lx_state != DWC2_L0) {
305 			if (hsotg->in_ppd) {
306 				ret = dwc2_exit_partial_power_down(hsotg, 0,
307 								   true);
308 				if (ret)
309 					dev_err(hsotg->dev,
310 						"exit power_down failed\n");
311 			}
312 
313 			/* Exit gadget mode clock gating. */
314 			if (hsotg->params.power_down ==
315 			    DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended &&
316 			    !hsotg->params.no_clock_gating)
317 				dwc2_gadget_exit_clock_gating(hsotg, 0);
318 		}
319 
320 		/*
321 		 * Report disconnect if there is any previous session
322 		 * established
323 		 */
324 		dwc2_hsotg_disconnect(hsotg);
325 	} else {
326 		/* Turn on the port power bit. */
327 		hprt0 = dwc2_read_hprt0(hsotg);
328 		hprt0 |= HPRT0_PWR;
329 		dwc2_writel(hsotg, hprt0, HPRT0);
330 		/* Connect hcd after port power is set. */
331 		dwc2_hcd_connect(hsotg);
332 	}
333 }
334 
335 /**
336  * dwc2_wakeup_from_lpm_l1 - Exit the device from LPM L1 state
337  * @hsotg: Programming view of DWC_otg controller
338  * @remotewakeup: Whether this is a remote wakeup
339  */
340 void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg, bool remotewakeup)
341 {
342 	u32 glpmcfg;
343 	u32 pcgctl;
344 	u32 dctl;
345 
346 	if (hsotg->lx_state != DWC2_L1) {
347 		dev_err(hsotg->dev, "Core isn't in DWC2_L1 state\n");
348 		return;
349 	}
350 
351 	glpmcfg = dwc2_readl(hsotg, GLPMCFG);
352 	if (dwc2_is_device_mode(hsotg)) {
353 		dev_dbg(hsotg->dev, "Exit from L1 state, remotewakeup=%d\n", remotewakeup);
354 		glpmcfg &= ~GLPMCFG_ENBLSLPM;
355 		glpmcfg &= ~GLPMCFG_HIRD_THRES_MASK;
356 		dwc2_writel(hsotg, glpmcfg, GLPMCFG);
357 
358 		pcgctl = dwc2_readl(hsotg, PCGCTL);
359 		pcgctl &= ~PCGCTL_ENBL_SLEEP_GATING;
360 		dwc2_writel(hsotg, pcgctl, PCGCTL);
361 
362 		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
363 		if (glpmcfg & GLPMCFG_ENBESL) {
364 			glpmcfg |= GLPMCFG_RSTRSLPSTS;
365 			dwc2_writel(hsotg, glpmcfg, GLPMCFG);
366 		}
367 
368 		if (remotewakeup) {
369 			if (dwc2_hsotg_wait_bit_set(hsotg, GLPMCFG, GLPMCFG_L1RESUMEOK, 1000)) {
370 				dev_warn(hsotg->dev, "%s: timeout GLPMCFG_L1RESUMEOK\n", __func__);
371 				goto fail;
372 				return;
373 			}
374 
375 			dctl = dwc2_readl(hsotg, DCTL);
376 			dctl |= DCTL_RMTWKUPSIG;
377 			dwc2_writel(hsotg, dctl, DCTL);
378 
379 			if (dwc2_hsotg_wait_bit_set(hsotg, GINTSTS, GINTSTS_WKUPINT, 1000)) {
380 				dev_warn(hsotg->dev, "%s: timeout GINTSTS_WKUPINT\n", __func__);
381 				goto fail;
382 				return;
383 			}
384 		}
385 
386 		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
387 		if (glpmcfg & GLPMCFG_COREL1RES_MASK || glpmcfg & GLPMCFG_SLPSTS ||
388 		    glpmcfg & GLPMCFG_L1RESUMEOK) {
389 			goto fail;
390 			return;
391 		}
392 
393 		/* Inform gadget to exit from L1 */
394 		call_gadget(hsotg, resume);
395 		/* Change to L0 state */
396 		hsotg->lx_state = DWC2_L0;
397 		hsotg->bus_suspended = false;
398 fail:		dwc2_gadget_init_lpm(hsotg);
399 	} else {
400 		/* TODO */
401 		dev_err(hsotg->dev, "Host side LPM is not supported.\n");
402 		return;
403 	}
404 }
405 
406 /*
407  * This interrupt indicates that the DWC_otg controller has detected a
408  * resume or remote wakeup sequence. If the DWC_otg controller is in
409  * low power mode, the handler must brings the controller out of low
410  * power mode. The controller automatically begins resume signaling.
411  * The handler schedules a time to stop resume signaling.
412  */
413 static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
414 {
415 	int ret;
416 
417 	/* Clear interrupt */
418 	dwc2_writel(hsotg, GINTSTS_WKUPINT, GINTSTS);
419 
420 	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
421 	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
422 
423 	if (hsotg->lx_state == DWC2_L1) {
424 		dwc2_wakeup_from_lpm_l1(hsotg, false);
425 		return;
426 	}
427 
428 	if (dwc2_is_device_mode(hsotg)) {
429 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n",
430 			dwc2_readl(hsotg, DSTS));
431 		if (hsotg->lx_state == DWC2_L2) {
432 			if (hsotg->in_ppd) {
433 				u32 dctl = dwc2_readl(hsotg, DCTL);
434 				/* Clear Remote Wakeup Signaling */
435 				dctl &= ~DCTL_RMTWKUPSIG;
436 				dwc2_writel(hsotg, dctl, DCTL);
437 				ret = dwc2_exit_partial_power_down(hsotg, 1,
438 								   true);
439 				if (ret)
440 					dev_err(hsotg->dev,
441 						"exit partial_power_down failed\n");
442 				call_gadget(hsotg, resume);
443 			}
444 
445 			/* Exit gadget mode clock gating. */
446 			if (hsotg->params.power_down ==
447 			    DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended &&
448 			    !hsotg->params.no_clock_gating)
449 				dwc2_gadget_exit_clock_gating(hsotg, 0);
450 		} else {
451 			/* Change to L0 state */
452 			hsotg->lx_state = DWC2_L0;
453 		}
454 	} else {
455 		if (hsotg->lx_state == DWC2_L2) {
456 			if (hsotg->in_ppd) {
457 				ret = dwc2_exit_partial_power_down(hsotg, 1,
458 								   true);
459 				if (ret)
460 					dev_err(hsotg->dev,
461 						"exit partial_power_down failed\n");
462 			}
463 
464 			if (hsotg->params.power_down ==
465 			    DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended &&
466 			    !hsotg->params.no_clock_gating)
467 				dwc2_host_exit_clock_gating(hsotg, 1);
468 
469 			/*
470 			 * If we've got this quirk then the PHY is stuck upon
471 			 * wakeup.  Assert reset.  This will propagate out and
472 			 * eventually we'll re-enumerate the device.  Not great
473 			 * but the best we can do.  We can't call phy_reset()
474 			 * at interrupt time but there's no hurry, so we'll
475 			 * schedule it for later.
476 			 */
477 			if (hsotg->reset_phy_on_wake)
478 				dwc2_host_schedule_phy_reset(hsotg);
479 
480 			mod_timer(&hsotg->wkp_timer,
481 				  jiffies + msecs_to_jiffies(71));
482 		} else {
483 			/* Change to L0 state */
484 			hsotg->lx_state = DWC2_L0;
485 		}
486 	}
487 }
488 
489 /*
490  * This interrupt indicates that a device has been disconnected from the
491  * root port
492  */
493 static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
494 {
495 	dwc2_writel(hsotg, GINTSTS_DISCONNINT, GINTSTS);
496 
497 	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
498 		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
499 		dwc2_op_state_str(hsotg));
500 
501 	if (hsotg->op_state == OTG_STATE_A_HOST)
502 		dwc2_hcd_disconnect(hsotg, false);
503 }
504 
505 /*
506  * This interrupt indicates that SUSPEND state has been detected on the USB.
507  *
508  * For HNP the USB Suspend interrupt signals the change from "a_peripheral"
509  * to "a_host".
510  *
511  * When power management is enabled the core will be put in low power mode.
512  */
513 static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
514 {
515 	u32 dsts;
516 	int ret;
517 
518 	/* Clear interrupt */
519 	dwc2_writel(hsotg, GINTSTS_USBSUSP, GINTSTS);
520 
521 	dev_dbg(hsotg->dev, "USB SUSPEND\n");
522 
523 	if (dwc2_is_device_mode(hsotg)) {
524 		/*
525 		 * Check the Device status register to determine if the Suspend
526 		 * state is active
527 		 */
528 		dsts = dwc2_readl(hsotg, DSTS);
529 		dev_dbg(hsotg->dev, "%s: DSTS=0x%0x\n", __func__, dsts);
530 		dev_dbg(hsotg->dev,
531 			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d HWCFG4.Hibernation=%d\n",
532 			!!(dsts & DSTS_SUSPSTS),
533 			hsotg->hw_params.power_optimized,
534 			hsotg->hw_params.hibernation);
535 
536 		/* Ignore suspend request before enumeration */
537 		if (!dwc2_is_device_connected(hsotg)) {
538 			dev_dbg(hsotg->dev,
539 				"ignore suspend request before enumeration\n");
540 			return;
541 		}
542 		if (dsts & DSTS_SUSPSTS) {
543 			switch (hsotg->params.power_down) {
544 			case DWC2_POWER_DOWN_PARAM_PARTIAL:
545 				ret = dwc2_enter_partial_power_down(hsotg);
546 				if (ret)
547 					dev_err(hsotg->dev,
548 						"enter partial_power_down failed\n");
549 
550 				udelay(100);
551 
552 				/* Ask phy to be suspended */
553 				if (!IS_ERR_OR_NULL(hsotg->uphy))
554 					usb_phy_set_suspend(hsotg->uphy, true);
555 				break;
556 			case DWC2_POWER_DOWN_PARAM_HIBERNATION:
557 				ret = dwc2_enter_hibernation(hsotg, 0);
558 				if (ret)
559 					dev_err(hsotg->dev,
560 						"enter hibernation failed\n");
561 				break;
562 			case DWC2_POWER_DOWN_PARAM_NONE:
563 				/*
564 				 * If neither hibernation nor partial power down are supported,
565 				 * clock gating is used to save power.
566 				 */
567 				if (!hsotg->params.no_clock_gating)
568 					dwc2_gadget_enter_clock_gating(hsotg);
569 			}
570 
571 			/*
572 			 * Change to L2 (suspend) state before releasing
573 			 * spinlock
574 			 */
575 			hsotg->lx_state = DWC2_L2;
576 
577 			/* Call gadget suspend callback */
578 			call_gadget(hsotg, suspend);
579 		}
580 	} else {
581 		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
582 			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
583 
584 			/* Change to L2 (suspend) state */
585 			hsotg->lx_state = DWC2_L2;
586 			/* Clear the a_peripheral flag, back to a_host */
587 			spin_unlock(&hsotg->lock);
588 			dwc2_hcd_start(hsotg);
589 			spin_lock(&hsotg->lock);
590 			hsotg->op_state = OTG_STATE_A_HOST;
591 		}
592 	}
593 }
594 
595 /**
596  * dwc2_handle_lpm_intr - GINTSTS_LPMTRANRCVD Interrupt handler
597  *
598  * @hsotg: Programming view of DWC_otg controller
599  *
600  */
601 static void dwc2_handle_lpm_intr(struct dwc2_hsotg *hsotg)
602 {
603 	u32 glpmcfg;
604 	u32 pcgcctl;
605 	u32 hird;
606 	u32 hird_thres;
607 	u32 hird_thres_en;
608 	u32 enslpm;
609 
610 	/* Clear interrupt */
611 	dwc2_writel(hsotg, GINTSTS_LPMTRANRCVD, GINTSTS);
612 
613 	glpmcfg = dwc2_readl(hsotg, GLPMCFG);
614 
615 	if (!(glpmcfg & GLPMCFG_LPMCAP)) {
616 		dev_err(hsotg->dev, "Unexpected LPM interrupt\n");
617 		return;
618 	}
619 
620 	hird = (glpmcfg & GLPMCFG_HIRD_MASK) >> GLPMCFG_HIRD_SHIFT;
621 	hird_thres = (glpmcfg & GLPMCFG_HIRD_THRES_MASK &
622 			~GLPMCFG_HIRD_THRES_EN) >> GLPMCFG_HIRD_THRES_SHIFT;
623 	hird_thres_en = glpmcfg & GLPMCFG_HIRD_THRES_EN;
624 	enslpm = glpmcfg & GLPMCFG_ENBLSLPM;
625 
626 	if (dwc2_is_device_mode(hsotg)) {
627 		dev_dbg(hsotg->dev, "HIRD_THRES_EN = %d\n", hird_thres_en);
628 
629 		if (hird_thres_en && hird >= hird_thres) {
630 			dev_dbg(hsotg->dev, "L1 with utmi_l1_suspend_n\n");
631 		} else if (enslpm) {
632 			dev_dbg(hsotg->dev, "L1 with utmi_sleep_n\n");
633 		} else {
634 			dev_dbg(hsotg->dev, "Entering Sleep with L1 Gating\n");
635 
636 			pcgcctl = dwc2_readl(hsotg, PCGCTL);
637 			pcgcctl |= PCGCTL_ENBL_SLEEP_GATING;
638 			dwc2_writel(hsotg, pcgcctl, PCGCTL);
639 		}
640 		/**
641 		 * Examine prt_sleep_sts after TL1TokenTetry period max (10 us)
642 		 */
643 		udelay(10);
644 
645 		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
646 
647 		if (glpmcfg & GLPMCFG_SLPSTS) {
648 			/* Save the current state */
649 			hsotg->lx_state = DWC2_L1;
650 			dev_dbg(hsotg->dev,
651 				"Core is in L1 sleep glpmcfg=%08x\n", glpmcfg);
652 
653 			/* Inform gadget that we are in L1 state */
654 			call_gadget(hsotg, suspend);
655 		}
656 	}
657 }
658 
659 #define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
660 			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
661 			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
662 			 GINTSTS_USBSUSP | GINTSTS_PRTINT |		\
663 			 GINTSTS_LPMTRANRCVD)
664 
665 /*
666  * This function returns the Core Interrupt register
667  */
668 static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
669 {
670 	u32 gintsts;
671 	u32 gintmsk;
672 	u32 gahbcfg;
673 	u32 gintmsk_common = GINTMSK_COMMON;
674 
675 	gintsts = dwc2_readl(hsotg, GINTSTS);
676 	gintmsk = dwc2_readl(hsotg, GINTMSK);
677 	gahbcfg = dwc2_readl(hsotg, GAHBCFG);
678 
679 	/* If any common interrupts set */
680 	if (gintsts & gintmsk_common)
681 		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
682 			gintsts, gintmsk);
683 
684 	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
685 		return gintsts & gintmsk & gintmsk_common;
686 	else
687 		return 0;
688 }
689 
690 /**
691  * dwc_handle_gpwrdn_disc_det() - Handles the gpwrdn disconnect detect.
692  * Exits hibernation without restoring registers.
693  *
694  * @hsotg: Programming view of DWC_otg controller
695  * @gpwrdn: GPWRDN register
696  */
697 static inline void dwc_handle_gpwrdn_disc_det(struct dwc2_hsotg *hsotg,
698 					      u32 gpwrdn)
699 {
700 	u32 gpwrdn_tmp;
701 
702 	/* Switch-on voltage to the core */
703 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
704 	gpwrdn_tmp &= ~GPWRDN_PWRDNSWTCH;
705 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
706 	udelay(5);
707 
708 	/* Reset core */
709 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
710 	gpwrdn_tmp &= ~GPWRDN_PWRDNRSTN;
711 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
712 	udelay(5);
713 
714 	/* Disable Power Down Clamp */
715 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
716 	gpwrdn_tmp &= ~GPWRDN_PWRDNCLMP;
717 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
718 	udelay(5);
719 
720 	/* Deassert reset core */
721 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
722 	gpwrdn_tmp |= GPWRDN_PWRDNRSTN;
723 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
724 	udelay(5);
725 
726 	/* Disable PMU interrupt */
727 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
728 	gpwrdn_tmp &= ~GPWRDN_PMUINTSEL;
729 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
730 
731 	/* Reset ULPI latch */
732 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
733 	gpwrdn &= ~GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
734 	dwc2_writel(hsotg, gpwrdn, GPWRDN);
735 
736 	/* De-assert Wakeup Logic */
737 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
738 	gpwrdn_tmp &= ~GPWRDN_PMUACTV;
739 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
740 
741 	hsotg->hibernated = 0;
742 	hsotg->bus_suspended = 0;
743 
744 	if (gpwrdn & GPWRDN_IDSTS) {
745 		hsotg->op_state = OTG_STATE_B_PERIPHERAL;
746 		dwc2_core_init(hsotg, false);
747 		dwc2_enable_global_interrupts(hsotg);
748 		dwc2_hsotg_core_init_disconnected(hsotg, false);
749 		dwc2_hsotg_core_connect(hsotg);
750 	} else {
751 		hsotg->op_state = OTG_STATE_A_HOST;
752 
753 		/* Initialize the Core for Host mode */
754 		dwc2_core_init(hsotg, false);
755 		dwc2_enable_global_interrupts(hsotg);
756 		dwc2_hcd_start(hsotg);
757 	}
758 }
759 
760 /*
761  * GPWRDN interrupt handler.
762  *
763  * The GPWRDN interrupts are those that occur in both Host and
764  * Device mode while core is in hibernated state.
765  */
766 static int dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
767 {
768 	u32 gpwrdn;
769 	int linestate;
770 	int ret = 0;
771 
772 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
773 	/* clear all interrupt */
774 	dwc2_writel(hsotg, gpwrdn, GPWRDN);
775 	linestate = (gpwrdn & GPWRDN_LINESTATE_MASK) >> GPWRDN_LINESTATE_SHIFT;
776 	dev_dbg(hsotg->dev,
777 		"%s: dwc2_handle_gpwrdwn_intr called gpwrdn= %08x\n", __func__,
778 		gpwrdn);
779 
780 	if ((gpwrdn & GPWRDN_DISCONN_DET) &&
781 	    (gpwrdn & GPWRDN_DISCONN_DET_MSK) && !linestate) {
782 		dev_dbg(hsotg->dev, "%s: GPWRDN_DISCONN_DET\n", __func__);
783 		/*
784 		 * Call disconnect detect function to exit from
785 		 * hibernation
786 		 */
787 		dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
788 	} else if ((gpwrdn & GPWRDN_LNSTSCHG) &&
789 		   (gpwrdn & GPWRDN_LNSTSCHG_MSK) && linestate) {
790 		dev_dbg(hsotg->dev, "%s: GPWRDN_LNSTSCHG\n", __func__);
791 		if (hsotg->hw_params.hibernation &&
792 		    hsotg->hibernated) {
793 			if (gpwrdn & GPWRDN_IDSTS) {
794 				ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
795 				if (ret)
796 					dev_err(hsotg->dev,
797 						"exit hibernation failed.\n");
798 				call_gadget(hsotg, resume);
799 			} else {
800 				ret = dwc2_exit_hibernation(hsotg, 1, 0, 1);
801 				if (ret)
802 					dev_err(hsotg->dev,
803 						"exit hibernation failed.\n");
804 			}
805 		}
806 	} else if ((gpwrdn & GPWRDN_RST_DET) &&
807 		   (gpwrdn & GPWRDN_RST_DET_MSK)) {
808 		dev_dbg(hsotg->dev, "%s: GPWRDN_RST_DET\n", __func__);
809 		if (!linestate) {
810 			ret = dwc2_exit_hibernation(hsotg, 0, 1, 0);
811 			if (ret)
812 				dev_err(hsotg->dev,
813 					"exit hibernation failed.\n");
814 		}
815 	} else if ((gpwrdn & GPWRDN_STS_CHGINT) &&
816 		   (gpwrdn & GPWRDN_STS_CHGINT_MSK)) {
817 		dev_dbg(hsotg->dev, "%s: GPWRDN_STS_CHGINT\n", __func__);
818 		/*
819 		 * As GPWRDN_STS_CHGINT exit from hibernation flow is
820 		 * the same as in GPWRDN_DISCONN_DET flow. Call
821 		 * disconnect detect helper function to exit from
822 		 * hibernation.
823 		 */
824 		dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
825 	}
826 
827 	return ret;
828 }
829 
830 /*
831  * Common interrupt handler
832  *
833  * The common interrupts are those that occur in both Host and Device mode.
834  * This handler handles the following interrupts:
835  * - Mode Mismatch Interrupt
836  * - OTG Interrupt
837  * - Connector ID Status Change Interrupt
838  * - Disconnect Interrupt
839  * - Session Request Interrupt
840  * - Resume / Remote Wakeup Detected Interrupt
841  * - Suspend Interrupt
842  */
843 irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
844 {
845 	struct dwc2_hsotg *hsotg = dev;
846 	u32 gintsts;
847 	irqreturn_t retval = IRQ_NONE;
848 
849 	spin_lock(&hsotg->lock);
850 
851 	if (!dwc2_is_controller_alive(hsotg)) {
852 		dev_warn(hsotg->dev, "Controller is dead\n");
853 		goto out;
854 	}
855 
856 	/* Reading current frame number value in device or host modes. */
857 	if (dwc2_is_device_mode(hsotg))
858 		hsotg->frame_number = (dwc2_readl(hsotg, DSTS)
859 				       & DSTS_SOFFN_MASK) >> DSTS_SOFFN_SHIFT;
860 	else
861 		hsotg->frame_number = (dwc2_readl(hsotg, HFNUM)
862 				       & HFNUM_FRNUM_MASK) >> HFNUM_FRNUM_SHIFT;
863 
864 	gintsts = dwc2_read_common_intr(hsotg);
865 	if (gintsts & ~GINTSTS_PRTINT)
866 		retval = IRQ_HANDLED;
867 
868 	/* In case of hibernated state gintsts must not work */
869 	if (hsotg->hibernated) {
870 		dwc2_handle_gpwrdn_intr(hsotg);
871 		retval = IRQ_HANDLED;
872 		goto out;
873 	}
874 
875 	if (gintsts & GINTSTS_MODEMIS)
876 		dwc2_handle_mode_mismatch_intr(hsotg);
877 	if (gintsts & GINTSTS_OTGINT)
878 		dwc2_handle_otg_intr(hsotg);
879 	if (gintsts & GINTSTS_CONIDSTSCHNG)
880 		dwc2_handle_conn_id_status_change_intr(hsotg);
881 	if (gintsts & GINTSTS_DISCONNINT)
882 		dwc2_handle_disconnect_intr(hsotg);
883 	if (gintsts & GINTSTS_SESSREQINT)
884 		dwc2_handle_session_req_intr(hsotg);
885 	if (gintsts & GINTSTS_WKUPINT)
886 		dwc2_handle_wakeup_detected_intr(hsotg);
887 	if (gintsts & GINTSTS_USBSUSP)
888 		dwc2_handle_usb_suspend_intr(hsotg);
889 	if (gintsts & GINTSTS_LPMTRANRCVD)
890 		dwc2_handle_lpm_intr(hsotg);
891 
892 	if (gintsts & GINTSTS_PRTINT) {
893 		/*
894 		 * The port interrupt occurs while in device mode with HPRT0
895 		 * Port Enable/Disable
896 		 */
897 		if (dwc2_is_device_mode(hsotg)) {
898 			dev_dbg(hsotg->dev,
899 				" --Port interrupt received in Device mode--\n");
900 			dwc2_handle_usb_port_intr(hsotg);
901 			retval = IRQ_HANDLED;
902 		}
903 	}
904 
905 out:
906 	spin_unlock(&hsotg->lock);
907 	return retval;
908 }
909