xref: /linux/drivers/usb/dwc2/core_intr.c (revision f898c16a0624e7f2dcb0b1cda6916c9be6489197)
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  *
338  * @hsotg: Programming view of DWC_otg controller
339  *
340  */
341 void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg, bool remotewakeup)
342 {
343 	u32 glpmcfg;
344 	u32 pcgctl;
345 	u32 dctl;
346 
347 	if (hsotg->lx_state != DWC2_L1) {
348 		dev_err(hsotg->dev, "Core isn't in DWC2_L1 state\n");
349 		return;
350 	}
351 
352 	glpmcfg = dwc2_readl(hsotg, GLPMCFG);
353 	if (dwc2_is_device_mode(hsotg)) {
354 		dev_dbg(hsotg->dev, "Exit from L1 state, remotewakeup=%d\n", remotewakeup);
355 		glpmcfg &= ~GLPMCFG_ENBLSLPM;
356 		glpmcfg &= ~GLPMCFG_HIRD_THRES_MASK;
357 		dwc2_writel(hsotg, glpmcfg, GLPMCFG);
358 
359 		pcgctl = dwc2_readl(hsotg, PCGCTL);
360 		pcgctl &= ~PCGCTL_ENBL_SLEEP_GATING;
361 		dwc2_writel(hsotg, pcgctl, PCGCTL);
362 
363 		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
364 		if (glpmcfg & GLPMCFG_ENBESL) {
365 			glpmcfg |= GLPMCFG_RSTRSLPSTS;
366 			dwc2_writel(hsotg, glpmcfg, GLPMCFG);
367 		}
368 
369 		if (remotewakeup) {
370 			if (dwc2_hsotg_wait_bit_set(hsotg, GLPMCFG, GLPMCFG_L1RESUMEOK, 1000)) {
371 				dev_warn(hsotg->dev, "%s: timeout GLPMCFG_L1RESUMEOK\n", __func__);
372 				goto fail;
373 				return;
374 			}
375 
376 			dctl = dwc2_readl(hsotg, DCTL);
377 			dctl |= DCTL_RMTWKUPSIG;
378 			dwc2_writel(hsotg, dctl, DCTL);
379 
380 			if (dwc2_hsotg_wait_bit_set(hsotg, GINTSTS, GINTSTS_WKUPINT, 1000)) {
381 				dev_warn(hsotg->dev, "%s: timeout GINTSTS_WKUPINT\n", __func__);
382 				goto fail;
383 				return;
384 			}
385 		}
386 
387 		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
388 		if (glpmcfg & GLPMCFG_COREL1RES_MASK || glpmcfg & GLPMCFG_SLPSTS ||
389 		    glpmcfg & GLPMCFG_L1RESUMEOK) {
390 			goto fail;
391 			return;
392 		}
393 
394 		/* Inform gadget to exit from L1 */
395 		call_gadget(hsotg, resume);
396 		/* Change to L0 state */
397 		hsotg->lx_state = DWC2_L0;
398 		hsotg->bus_suspended = false;
399 fail:		dwc2_gadget_init_lpm(hsotg);
400 	} else {
401 		/* TODO */
402 		dev_err(hsotg->dev, "Host side LPM is not supported.\n");
403 		return;
404 	}
405 }
406 
407 /*
408  * This interrupt indicates that the DWC_otg controller has detected a
409  * resume or remote wakeup sequence. If the DWC_otg controller is in
410  * low power mode, the handler must brings the controller out of low
411  * power mode. The controller automatically begins resume signaling.
412  * The handler schedules a time to stop resume signaling.
413  */
414 static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
415 {
416 	int ret;
417 
418 	/* Clear interrupt */
419 	dwc2_writel(hsotg, GINTSTS_WKUPINT, GINTSTS);
420 
421 	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
422 	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
423 
424 	if (hsotg->lx_state == DWC2_L1) {
425 		dwc2_wakeup_from_lpm_l1(hsotg, false);
426 		return;
427 	}
428 
429 	if (dwc2_is_device_mode(hsotg)) {
430 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n",
431 			dwc2_readl(hsotg, DSTS));
432 		if (hsotg->lx_state == DWC2_L2) {
433 			if (hsotg->in_ppd) {
434 				u32 dctl = dwc2_readl(hsotg, DCTL);
435 				/* Clear Remote Wakeup Signaling */
436 				dctl &= ~DCTL_RMTWKUPSIG;
437 				dwc2_writel(hsotg, dctl, DCTL);
438 				ret = dwc2_exit_partial_power_down(hsotg, 1,
439 								   true);
440 				if (ret)
441 					dev_err(hsotg->dev,
442 						"exit partial_power_down failed\n");
443 				call_gadget(hsotg, resume);
444 			}
445 
446 			/* Exit gadget mode clock gating. */
447 			if (hsotg->params.power_down ==
448 			    DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended &&
449 			    !hsotg->params.no_clock_gating)
450 				dwc2_gadget_exit_clock_gating(hsotg, 0);
451 		} else {
452 			/* Change to L0 state */
453 			hsotg->lx_state = DWC2_L0;
454 		}
455 	} else {
456 		if (hsotg->lx_state == DWC2_L2) {
457 			if (hsotg->in_ppd) {
458 				ret = dwc2_exit_partial_power_down(hsotg, 1,
459 								   true);
460 				if (ret)
461 					dev_err(hsotg->dev,
462 						"exit partial_power_down failed\n");
463 			}
464 
465 			if (hsotg->params.power_down ==
466 			    DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended &&
467 			    !hsotg->params.no_clock_gating)
468 				dwc2_host_exit_clock_gating(hsotg, 1);
469 
470 			/*
471 			 * If we've got this quirk then the PHY is stuck upon
472 			 * wakeup.  Assert reset.  This will propagate out and
473 			 * eventually we'll re-enumerate the device.  Not great
474 			 * but the best we can do.  We can't call phy_reset()
475 			 * at interrupt time but there's no hurry, so we'll
476 			 * schedule it for later.
477 			 */
478 			if (hsotg->reset_phy_on_wake)
479 				dwc2_host_schedule_phy_reset(hsotg);
480 
481 			mod_timer(&hsotg->wkp_timer,
482 				  jiffies + msecs_to_jiffies(71));
483 		} else {
484 			/* Change to L0 state */
485 			hsotg->lx_state = DWC2_L0;
486 		}
487 	}
488 }
489 
490 /*
491  * This interrupt indicates that a device has been disconnected from the
492  * root port
493  */
494 static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
495 {
496 	dwc2_writel(hsotg, GINTSTS_DISCONNINT, GINTSTS);
497 
498 	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
499 		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
500 		dwc2_op_state_str(hsotg));
501 
502 	if (hsotg->op_state == OTG_STATE_A_HOST)
503 		dwc2_hcd_disconnect(hsotg, false);
504 }
505 
506 /*
507  * This interrupt indicates that SUSPEND state has been detected on the USB.
508  *
509  * For HNP the USB Suspend interrupt signals the change from "a_peripheral"
510  * to "a_host".
511  *
512  * When power management is enabled the core will be put in low power mode.
513  */
514 static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
515 {
516 	u32 dsts;
517 	int ret;
518 
519 	/* Clear interrupt */
520 	dwc2_writel(hsotg, GINTSTS_USBSUSP, GINTSTS);
521 
522 	dev_dbg(hsotg->dev, "USB SUSPEND\n");
523 
524 	if (dwc2_is_device_mode(hsotg)) {
525 		/*
526 		 * Check the Device status register to determine if the Suspend
527 		 * state is active
528 		 */
529 		dsts = dwc2_readl(hsotg, DSTS);
530 		dev_dbg(hsotg->dev, "%s: DSTS=0x%0x\n", __func__, dsts);
531 		dev_dbg(hsotg->dev,
532 			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d HWCFG4.Hibernation=%d\n",
533 			!!(dsts & DSTS_SUSPSTS),
534 			hsotg->hw_params.power_optimized,
535 			hsotg->hw_params.hibernation);
536 
537 		/* Ignore suspend request before enumeration */
538 		if (!dwc2_is_device_connected(hsotg)) {
539 			dev_dbg(hsotg->dev,
540 				"ignore suspend request before enumeration\n");
541 			return;
542 		}
543 		if (dsts & DSTS_SUSPSTS) {
544 			switch (hsotg->params.power_down) {
545 			case DWC2_POWER_DOWN_PARAM_PARTIAL:
546 				ret = dwc2_enter_partial_power_down(hsotg);
547 				if (ret)
548 					dev_err(hsotg->dev,
549 						"enter partial_power_down failed\n");
550 
551 				udelay(100);
552 
553 				/* Ask phy to be suspended */
554 				if (!IS_ERR_OR_NULL(hsotg->uphy))
555 					usb_phy_set_suspend(hsotg->uphy, true);
556 				break;
557 			case DWC2_POWER_DOWN_PARAM_HIBERNATION:
558 				ret = dwc2_enter_hibernation(hsotg, 0);
559 				if (ret)
560 					dev_err(hsotg->dev,
561 						"enter hibernation failed\n");
562 				break;
563 			case DWC2_POWER_DOWN_PARAM_NONE:
564 				/*
565 				 * If neither hibernation nor partial power down are supported,
566 				 * clock gating is used to save power.
567 				 */
568 				if (!hsotg->params.no_clock_gating)
569 					dwc2_gadget_enter_clock_gating(hsotg);
570 			}
571 
572 			/*
573 			 * Change to L2 (suspend) state before releasing
574 			 * spinlock
575 			 */
576 			hsotg->lx_state = DWC2_L2;
577 
578 			/* Call gadget suspend callback */
579 			call_gadget(hsotg, suspend);
580 		}
581 	} else {
582 		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
583 			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
584 
585 			/* Change to L2 (suspend) state */
586 			hsotg->lx_state = DWC2_L2;
587 			/* Clear the a_peripheral flag, back to a_host */
588 			spin_unlock(&hsotg->lock);
589 			dwc2_hcd_start(hsotg);
590 			spin_lock(&hsotg->lock);
591 			hsotg->op_state = OTG_STATE_A_HOST;
592 		}
593 	}
594 }
595 
596 /**
597  * dwc2_handle_lpm_intr - GINTSTS_LPMTRANRCVD Interrupt handler
598  *
599  * @hsotg: Programming view of DWC_otg controller
600  *
601  */
602 static void dwc2_handle_lpm_intr(struct dwc2_hsotg *hsotg)
603 {
604 	u32 glpmcfg;
605 	u32 pcgcctl;
606 	u32 hird;
607 	u32 hird_thres;
608 	u32 hird_thres_en;
609 	u32 enslpm;
610 
611 	/* Clear interrupt */
612 	dwc2_writel(hsotg, GINTSTS_LPMTRANRCVD, GINTSTS);
613 
614 	glpmcfg = dwc2_readl(hsotg, GLPMCFG);
615 
616 	if (!(glpmcfg & GLPMCFG_LPMCAP)) {
617 		dev_err(hsotg->dev, "Unexpected LPM interrupt\n");
618 		return;
619 	}
620 
621 	hird = (glpmcfg & GLPMCFG_HIRD_MASK) >> GLPMCFG_HIRD_SHIFT;
622 	hird_thres = (glpmcfg & GLPMCFG_HIRD_THRES_MASK &
623 			~GLPMCFG_HIRD_THRES_EN) >> GLPMCFG_HIRD_THRES_SHIFT;
624 	hird_thres_en = glpmcfg & GLPMCFG_HIRD_THRES_EN;
625 	enslpm = glpmcfg & GLPMCFG_ENBLSLPM;
626 
627 	if (dwc2_is_device_mode(hsotg)) {
628 		dev_dbg(hsotg->dev, "HIRD_THRES_EN = %d\n", hird_thres_en);
629 
630 		if (hird_thres_en && hird >= hird_thres) {
631 			dev_dbg(hsotg->dev, "L1 with utmi_l1_suspend_n\n");
632 		} else if (enslpm) {
633 			dev_dbg(hsotg->dev, "L1 with utmi_sleep_n\n");
634 		} else {
635 			dev_dbg(hsotg->dev, "Entering Sleep with L1 Gating\n");
636 
637 			pcgcctl = dwc2_readl(hsotg, PCGCTL);
638 			pcgcctl |= PCGCTL_ENBL_SLEEP_GATING;
639 			dwc2_writel(hsotg, pcgcctl, PCGCTL);
640 		}
641 		/**
642 		 * Examine prt_sleep_sts after TL1TokenTetry period max (10 us)
643 		 */
644 		udelay(10);
645 
646 		glpmcfg = dwc2_readl(hsotg, GLPMCFG);
647 
648 		if (glpmcfg & GLPMCFG_SLPSTS) {
649 			/* Save the current state */
650 			hsotg->lx_state = DWC2_L1;
651 			dev_dbg(hsotg->dev,
652 				"Core is in L1 sleep glpmcfg=%08x\n", glpmcfg);
653 
654 			/* Inform gadget that we are in L1 state */
655 			call_gadget(hsotg, suspend);
656 		}
657 	}
658 }
659 
660 #define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
661 			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
662 			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
663 			 GINTSTS_USBSUSP | GINTSTS_PRTINT |		\
664 			 GINTSTS_LPMTRANRCVD)
665 
666 /*
667  * This function returns the Core Interrupt register
668  */
669 static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
670 {
671 	u32 gintsts;
672 	u32 gintmsk;
673 	u32 gahbcfg;
674 	u32 gintmsk_common = GINTMSK_COMMON;
675 
676 	gintsts = dwc2_readl(hsotg, GINTSTS);
677 	gintmsk = dwc2_readl(hsotg, GINTMSK);
678 	gahbcfg = dwc2_readl(hsotg, GAHBCFG);
679 
680 	/* If any common interrupts set */
681 	if (gintsts & gintmsk_common)
682 		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
683 			gintsts, gintmsk);
684 
685 	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
686 		return gintsts & gintmsk & gintmsk_common;
687 	else
688 		return 0;
689 }
690 
691 /**
692  * dwc_handle_gpwrdn_disc_det() - Handles the gpwrdn disconnect detect.
693  * Exits hibernation without restoring registers.
694  *
695  * @hsotg: Programming view of DWC_otg controller
696  * @gpwrdn: GPWRDN register
697  */
698 static inline void dwc_handle_gpwrdn_disc_det(struct dwc2_hsotg *hsotg,
699 					      u32 gpwrdn)
700 {
701 	u32 gpwrdn_tmp;
702 
703 	/* Switch-on voltage to the core */
704 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
705 	gpwrdn_tmp &= ~GPWRDN_PWRDNSWTCH;
706 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
707 	udelay(5);
708 
709 	/* Reset core */
710 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
711 	gpwrdn_tmp &= ~GPWRDN_PWRDNRSTN;
712 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
713 	udelay(5);
714 
715 	/* Disable Power Down Clamp */
716 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
717 	gpwrdn_tmp &= ~GPWRDN_PWRDNCLMP;
718 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
719 	udelay(5);
720 
721 	/* Deassert reset core */
722 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
723 	gpwrdn_tmp |= GPWRDN_PWRDNRSTN;
724 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
725 	udelay(5);
726 
727 	/* Disable PMU interrupt */
728 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
729 	gpwrdn_tmp &= ~GPWRDN_PMUINTSEL;
730 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
731 
732 	/* Reset ULPI latch */
733 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
734 	gpwrdn &= ~GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
735 	dwc2_writel(hsotg, gpwrdn, GPWRDN);
736 
737 	/* De-assert Wakeup Logic */
738 	gpwrdn_tmp = dwc2_readl(hsotg, GPWRDN);
739 	gpwrdn_tmp &= ~GPWRDN_PMUACTV;
740 	dwc2_writel(hsotg, gpwrdn_tmp, GPWRDN);
741 
742 	hsotg->hibernated = 0;
743 	hsotg->bus_suspended = 0;
744 
745 	if (gpwrdn & GPWRDN_IDSTS) {
746 		hsotg->op_state = OTG_STATE_B_PERIPHERAL;
747 		dwc2_core_init(hsotg, false);
748 		dwc2_enable_global_interrupts(hsotg);
749 		dwc2_hsotg_core_init_disconnected(hsotg, false);
750 		dwc2_hsotg_core_connect(hsotg);
751 	} else {
752 		hsotg->op_state = OTG_STATE_A_HOST;
753 
754 		/* Initialize the Core for Host mode */
755 		dwc2_core_init(hsotg, false);
756 		dwc2_enable_global_interrupts(hsotg);
757 		dwc2_hcd_start(hsotg);
758 	}
759 }
760 
761 /*
762  * GPWRDN interrupt handler.
763  *
764  * The GPWRDN interrupts are those that occur in both Host and
765  * Device mode while core is in hibernated state.
766  */
767 static int dwc2_handle_gpwrdn_intr(struct dwc2_hsotg *hsotg)
768 {
769 	u32 gpwrdn;
770 	int linestate;
771 	int ret = 0;
772 
773 	gpwrdn = dwc2_readl(hsotg, GPWRDN);
774 	/* clear all interrupt */
775 	dwc2_writel(hsotg, gpwrdn, GPWRDN);
776 	linestate = (gpwrdn & GPWRDN_LINESTATE_MASK) >> GPWRDN_LINESTATE_SHIFT;
777 	dev_dbg(hsotg->dev,
778 		"%s: dwc2_handle_gpwrdwn_intr called gpwrdn= %08x\n", __func__,
779 		gpwrdn);
780 
781 	if ((gpwrdn & GPWRDN_DISCONN_DET) &&
782 	    (gpwrdn & GPWRDN_DISCONN_DET_MSK) && !linestate) {
783 		dev_dbg(hsotg->dev, "%s: GPWRDN_DISCONN_DET\n", __func__);
784 		/*
785 		 * Call disconnect detect function to exit from
786 		 * hibernation
787 		 */
788 		dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
789 	} else if ((gpwrdn & GPWRDN_LNSTSCHG) &&
790 		   (gpwrdn & GPWRDN_LNSTSCHG_MSK) && linestate) {
791 		dev_dbg(hsotg->dev, "%s: GPWRDN_LNSTSCHG\n", __func__);
792 		if (hsotg->hw_params.hibernation &&
793 		    hsotg->hibernated) {
794 			if (gpwrdn & GPWRDN_IDSTS) {
795 				ret = dwc2_exit_hibernation(hsotg, 0, 0, 0);
796 				if (ret)
797 					dev_err(hsotg->dev,
798 						"exit hibernation failed.\n");
799 				call_gadget(hsotg, resume);
800 			} else {
801 				ret = dwc2_exit_hibernation(hsotg, 1, 0, 1);
802 				if (ret)
803 					dev_err(hsotg->dev,
804 						"exit hibernation failed.\n");
805 			}
806 		}
807 	} else if ((gpwrdn & GPWRDN_RST_DET) &&
808 		   (gpwrdn & GPWRDN_RST_DET_MSK)) {
809 		dev_dbg(hsotg->dev, "%s: GPWRDN_RST_DET\n", __func__);
810 		if (!linestate) {
811 			ret = dwc2_exit_hibernation(hsotg, 0, 1, 0);
812 			if (ret)
813 				dev_err(hsotg->dev,
814 					"exit hibernation failed.\n");
815 		}
816 	} else if ((gpwrdn & GPWRDN_STS_CHGINT) &&
817 		   (gpwrdn & GPWRDN_STS_CHGINT_MSK)) {
818 		dev_dbg(hsotg->dev, "%s: GPWRDN_STS_CHGINT\n", __func__);
819 		/*
820 		 * As GPWRDN_STS_CHGINT exit from hibernation flow is
821 		 * the same as in GPWRDN_DISCONN_DET flow. Call
822 		 * disconnect detect helper function to exit from
823 		 * hibernation.
824 		 */
825 		dwc_handle_gpwrdn_disc_det(hsotg, gpwrdn);
826 	}
827 
828 	return ret;
829 }
830 
831 /*
832  * Common interrupt handler
833  *
834  * The common interrupts are those that occur in both Host and Device mode.
835  * This handler handles the following interrupts:
836  * - Mode Mismatch Interrupt
837  * - OTG Interrupt
838  * - Connector ID Status Change Interrupt
839  * - Disconnect Interrupt
840  * - Session Request Interrupt
841  * - Resume / Remote Wakeup Detected Interrupt
842  * - Suspend Interrupt
843  */
844 irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
845 {
846 	struct dwc2_hsotg *hsotg = dev;
847 	u32 gintsts;
848 	irqreturn_t retval = IRQ_NONE;
849 
850 	spin_lock(&hsotg->lock);
851 
852 	if (!dwc2_is_controller_alive(hsotg)) {
853 		dev_warn(hsotg->dev, "Controller is dead\n");
854 		goto out;
855 	}
856 
857 	/* Reading current frame number value in device or host modes. */
858 	if (dwc2_is_device_mode(hsotg))
859 		hsotg->frame_number = (dwc2_readl(hsotg, DSTS)
860 				       & DSTS_SOFFN_MASK) >> DSTS_SOFFN_SHIFT;
861 	else
862 		hsotg->frame_number = (dwc2_readl(hsotg, HFNUM)
863 				       & HFNUM_FRNUM_MASK) >> HFNUM_FRNUM_SHIFT;
864 
865 	gintsts = dwc2_read_common_intr(hsotg);
866 	if (gintsts & ~GINTSTS_PRTINT)
867 		retval = IRQ_HANDLED;
868 
869 	/* In case of hibernated state gintsts must not work */
870 	if (hsotg->hibernated) {
871 		dwc2_handle_gpwrdn_intr(hsotg);
872 		retval = IRQ_HANDLED;
873 		goto out;
874 	}
875 
876 	if (gintsts & GINTSTS_MODEMIS)
877 		dwc2_handle_mode_mismatch_intr(hsotg);
878 	if (gintsts & GINTSTS_OTGINT)
879 		dwc2_handle_otg_intr(hsotg);
880 	if (gintsts & GINTSTS_CONIDSTSCHNG)
881 		dwc2_handle_conn_id_status_change_intr(hsotg);
882 	if (gintsts & GINTSTS_DISCONNINT)
883 		dwc2_handle_disconnect_intr(hsotg);
884 	if (gintsts & GINTSTS_SESSREQINT)
885 		dwc2_handle_session_req_intr(hsotg);
886 	if (gintsts & GINTSTS_WKUPINT)
887 		dwc2_handle_wakeup_detected_intr(hsotg);
888 	if (gintsts & GINTSTS_USBSUSP)
889 		dwc2_handle_usb_suspend_intr(hsotg);
890 	if (gintsts & GINTSTS_LPMTRANRCVD)
891 		dwc2_handle_lpm_intr(hsotg);
892 
893 	if (gintsts & GINTSTS_PRTINT) {
894 		/*
895 		 * The port interrupt occurs while in device mode with HPRT0
896 		 * Port Enable/Disable
897 		 */
898 		if (dwc2_is_device_mode(hsotg)) {
899 			dev_dbg(hsotg->dev,
900 				" --Port interrupt received in Device mode--\n");
901 			dwc2_handle_usb_port_intr(hsotg);
902 			retval = IRQ_HANDLED;
903 		}
904 	}
905 
906 out:
907 	spin_unlock(&hsotg->lock);
908 	return retval;
909 }
910