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 = readl(hsotg->regs + HPRT0);
84
85	if (hprt0 & HPRT0_ENACHG) {
86		hprt0 &= ~HPRT0_ENA;
87		writel(hprt0, hsotg->regs + HPRT0);
88	}
89
90	/* Clear interrupt */
91	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	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 = readl(hsotg->regs + GOTGINT);
121	gotgctl = 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 = readl(hsotg->regs + GOTGCTL);
130
131		if (dwc2_is_device_mode(hsotg))
132			s3c_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 = readl(hsotg->regs + GOTGCTL);
156		gotgctl &= ~GOTGCTL_DEVHNPEN;
157		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 = 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 = readl(hsotg->regs + GOTGCTL);
172				gotgctl &= ~GOTGCTL_SESREQ;
173				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 = 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 = readl(hsotg->regs + GINTMSK);
204				gintmsk &= ~GINTSTS_SOF;
205				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 = readl(hsotg->regs + GOTGCTL);
220			gotgctl &= ~(GOTGCTL_HNPREQ | GOTGCTL_DEVHNPEN);
221			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 = readl(hsotg->regs + GINTMSK);
248			gintmsk &= ~GINTSTS_SOF;
249			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	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 = readl(hsotg->regs + GINTMSK);
280
281	/* Need to disable SOF interrupt immediately */
282	gintmsk &= ~GINTSTS_SOF;
283	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	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	dev_dbg(hsotg->dev, "++Session Request Interrupt++\n");
317
318	/* Clear interrupt */
319	writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);
320
321	/*
322	 * Report disconnect if there is any previous session established
323	 */
324	if (dwc2_is_device_mode(hsotg))
325		s3c_hsotg_disconnect(hsotg);
326}
327
328/*
329 * This interrupt indicates that the DWC_otg controller has detected a
330 * resume or remote wakeup sequence. If the DWC_otg controller is in
331 * low power mode, the handler must brings the controller out of low
332 * power mode. The controller automatically begins resume signaling.
333 * The handler schedules a time to stop resume signaling.
334 */
335static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
336{
337	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
338	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
339
340	if (dwc2_is_device_mode(hsotg)) {
341		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", readl(hsotg->regs + DSTS));
342		if (hsotg->lx_state == DWC2_L2) {
343			u32 dctl = readl(hsotg->regs + DCTL);
344
345			/* Clear Remote Wakeup Signaling */
346			dctl &= ~DCTL_RMTWKUPSIG;
347			writel(dctl, hsotg->regs + DCTL);
348		}
349		/* Change to L0 state */
350		hsotg->lx_state = DWC2_L0;
351	} else {
352		if (hsotg->lx_state != DWC2_L1) {
353			u32 pcgcctl = readl(hsotg->regs + PCGCTL);
354
355			/* Restart the Phy Clock */
356			pcgcctl &= ~PCGCTL_STOPPCLK;
357			writel(pcgcctl, hsotg->regs + PCGCTL);
358			mod_timer(&hsotg->wkp_timer,
359				  jiffies + msecs_to_jiffies(71));
360		} else {
361			/* Change to L0 state */
362			hsotg->lx_state = DWC2_L0;
363		}
364	}
365
366	/* Clear interrupt */
367	writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
368}
369
370/*
371 * This interrupt indicates that a device has been disconnected from the
372 * root port
373 */
374static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
375{
376	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
377		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
378		dwc2_op_state_str(hsotg));
379
380	if (hsotg->op_state == OTG_STATE_A_HOST)
381		dwc2_hcd_disconnect(hsotg);
382
383	/* Change to L3 (OFF) state */
384	hsotg->lx_state = DWC2_L3;
385
386	writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
387}
388
389/*
390 * This interrupt indicates that SUSPEND state has been detected on the USB.
391 *
392 * For HNP the USB Suspend interrupt signals the change from "a_peripheral"
393 * to "a_host".
394 *
395 * When power management is enabled the core will be put in low power mode.
396 */
397static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
398{
399	u32 dsts;
400
401	dev_dbg(hsotg->dev, "USB SUSPEND\n");
402
403	if (dwc2_is_device_mode(hsotg)) {
404		/*
405		 * Check the Device status register to determine if the Suspend
406		 * state is active
407		 */
408		dsts = readl(hsotg->regs + DSTS);
409		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", dsts);
410		dev_dbg(hsotg->dev,
411			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
412			!!(dsts & DSTS_SUSPSTS),
413			hsotg->hw_params.power_optimized);
414	} else {
415		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
416			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
417
418			/* Clear the a_peripheral flag, back to a_host */
419			spin_unlock(&hsotg->lock);
420			dwc2_hcd_start(hsotg);
421			spin_lock(&hsotg->lock);
422			hsotg->op_state = OTG_STATE_A_HOST;
423		}
424	}
425
426	/* Change to L2 (suspend) state */
427	hsotg->lx_state = DWC2_L2;
428
429	/* Clear interrupt */
430	writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
431}
432
433#define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
434			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
435			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
436			 GINTSTS_USBSUSP | GINTSTS_PRTINT)
437
438/*
439 * This function returns the Core Interrupt register
440 */
441static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
442{
443	u32 gintsts;
444	u32 gintmsk;
445	u32 gahbcfg;
446	u32 gintmsk_common = GINTMSK_COMMON;
447
448	gintsts = readl(hsotg->regs + GINTSTS);
449	gintmsk = readl(hsotg->regs + GINTMSK);
450	gahbcfg = readl(hsotg->regs + GAHBCFG);
451
452	/* If any common interrupts set */
453	if (gintsts & gintmsk_common)
454		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
455			gintsts, gintmsk);
456
457	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
458		return gintsts & gintmsk & gintmsk_common;
459	else
460		return 0;
461}
462
463/*
464 * Common interrupt handler
465 *
466 * The common interrupts are those that occur in both Host and Device mode.
467 * This handler handles the following interrupts:
468 * - Mode Mismatch Interrupt
469 * - OTG Interrupt
470 * - Connector ID Status Change Interrupt
471 * - Disconnect Interrupt
472 * - Session Request Interrupt
473 * - Resume / Remote Wakeup Detected Interrupt
474 * - Suspend Interrupt
475 */
476irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
477{
478	struct dwc2_hsotg *hsotg = dev;
479	u32 gintsts;
480	irqreturn_t retval = IRQ_NONE;
481
482	spin_lock(&hsotg->lock);
483
484	if (!dwc2_is_controller_alive(hsotg)) {
485		dev_warn(hsotg->dev, "Controller is dead\n");
486		goto out;
487	}
488
489	gintsts = dwc2_read_common_intr(hsotg);
490	if (gintsts & ~GINTSTS_PRTINT)
491		retval = IRQ_HANDLED;
492
493	if (gintsts & GINTSTS_MODEMIS)
494		dwc2_handle_mode_mismatch_intr(hsotg);
495	if (gintsts & GINTSTS_OTGINT)
496		dwc2_handle_otg_intr(hsotg);
497	if (gintsts & GINTSTS_CONIDSTSCHNG)
498		dwc2_handle_conn_id_status_change_intr(hsotg);
499	if (gintsts & GINTSTS_DISCONNINT)
500		dwc2_handle_disconnect_intr(hsotg);
501	if (gintsts & GINTSTS_SESSREQINT)
502		dwc2_handle_session_req_intr(hsotg);
503	if (gintsts & GINTSTS_WKUPINT)
504		dwc2_handle_wakeup_detected_intr(hsotg);
505	if (gintsts & GINTSTS_USBSUSP)
506		dwc2_handle_usb_suspend_intr(hsotg);
507
508	if (gintsts & GINTSTS_PRTINT) {
509		/*
510		 * The port interrupt occurs while in device mode with HPRT0
511		 * Port Enable/Disable
512		 */
513		if (dwc2_is_device_mode(hsotg)) {
514			dev_dbg(hsotg->dev,
515				" --Port interrupt received in Device mode--\n");
516			dwc2_handle_usb_port_intr(hsotg);
517			retval = IRQ_HANDLED;
518		}
519	}
520
521out:
522	spin_unlock(&hsotg->lock);
523	return retval;
524}
525EXPORT_SYMBOL_GPL(dwc2_handle_common_intr);
526