xref: /openbmc/linux/drivers/usb/dwc2/core_intr.c (revision 206204a1)
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 
56 static 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  */
81 static 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  */
99 static 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  */
114 static 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 (hsotg->op_state == OTG_STATE_B_HOST) {
132 			hsotg->op_state = OTG_STATE_B_PERIPHERAL;
133 		} else {
134 			/*
135 			 * If not B_HOST and Device HNP still set, HNP did
136 			 * not succeed!
137 			 */
138 			if (gotgctl & GOTGCTL_DEVHNPEN) {
139 				dev_dbg(hsotg->dev, "Session End Detected\n");
140 				dev_err(hsotg->dev,
141 					"Device Not Connected/Responding!\n");
142 			}
143 
144 			/*
145 			 * If Session End Detected the B-Cable has been
146 			 * disconnected
147 			 */
148 			/* Reset to a clean state */
149 			hsotg->lx_state = DWC2_L0;
150 		}
151 
152 		gotgctl = readl(hsotg->regs + GOTGCTL);
153 		gotgctl &= ~GOTGCTL_DEVHNPEN;
154 		writel(gotgctl, hsotg->regs + GOTGCTL);
155 	}
156 
157 	if (gotgint & GOTGINT_SES_REQ_SUC_STS_CHNG) {
158 		dev_dbg(hsotg->dev,
159 			" ++OTG Interrupt: Session Request Success Status Change++\n");
160 		gotgctl = readl(hsotg->regs + GOTGCTL);
161 		if (gotgctl & GOTGCTL_SESREQSCS) {
162 			if (hsotg->core_params->phy_type ==
163 					DWC2_PHY_TYPE_PARAM_FS
164 			    && hsotg->core_params->i2c_enable > 0) {
165 				hsotg->srp_success = 1;
166 			} else {
167 				/* Clear Session Request */
168 				gotgctl = readl(hsotg->regs + GOTGCTL);
169 				gotgctl &= ~GOTGCTL_SESREQ;
170 				writel(gotgctl, hsotg->regs + GOTGCTL);
171 			}
172 		}
173 	}
174 
175 	if (gotgint & GOTGINT_HST_NEG_SUC_STS_CHNG) {
176 		/*
177 		 * Print statements during the HNP interrupt handling
178 		 * can cause it to fail
179 		 */
180 		gotgctl = readl(hsotg->regs + GOTGCTL);
181 		/*
182 		 * WA for 3.00a- HW is not setting cur_mode, even sometimes
183 		 * this does not help
184 		 */
185 		if (hsotg->hw_params.snpsid >= DWC2_CORE_REV_3_00a)
186 			udelay(100);
187 		if (gotgctl & GOTGCTL_HSTNEGSCS) {
188 			if (dwc2_is_host_mode(hsotg)) {
189 				hsotg->op_state = OTG_STATE_B_HOST;
190 				/*
191 				 * Need to disable SOF interrupt immediately.
192 				 * When switching from device to host, the PCD
193 				 * interrupt handler won't handle the interrupt
194 				 * if host mode is already set. The HCD
195 				 * interrupt handler won't get called if the
196 				 * HCD state is HALT. This means that the
197 				 * interrupt does not get handled and Linux
198 				 * complains loudly.
199 				 */
200 				gintmsk = readl(hsotg->regs + GINTMSK);
201 				gintmsk &= ~GINTSTS_SOF;
202 				writel(gintmsk, hsotg->regs + GINTMSK);
203 
204 				/*
205 				 * Call callback function with spin lock
206 				 * released
207 				 */
208 				spin_unlock(&hsotg->lock);
209 
210 				/* Initialize the Core for Host mode */
211 				dwc2_hcd_start(hsotg);
212 				spin_lock(&hsotg->lock);
213 				hsotg->op_state = OTG_STATE_B_HOST;
214 			}
215 		} else {
216 			gotgctl = readl(hsotg->regs + GOTGCTL);
217 			gotgctl &= ~(GOTGCTL_HNPREQ | GOTGCTL_DEVHNPEN);
218 			writel(gotgctl, hsotg->regs + GOTGCTL);
219 			dev_dbg(hsotg->dev, "HNP Failed\n");
220 			dev_err(hsotg->dev,
221 				"Device Not Connected/Responding\n");
222 		}
223 	}
224 
225 	if (gotgint & GOTGINT_HST_NEG_DET) {
226 		/*
227 		 * The disconnect interrupt is set at the same time as
228 		 * Host Negotiation Detected. During the mode switch all
229 		 * interrupts are cleared so the disconnect interrupt
230 		 * handler will not get executed.
231 		 */
232 		dev_dbg(hsotg->dev,
233 			" ++OTG Interrupt: Host Negotiation Detected++ (%s)\n",
234 			(dwc2_is_host_mode(hsotg) ? "Host" : "Device"));
235 		if (dwc2_is_device_mode(hsotg)) {
236 			dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n",
237 				hsotg->op_state);
238 			spin_unlock(&hsotg->lock);
239 			dwc2_hcd_disconnect(hsotg);
240 			spin_lock(&hsotg->lock);
241 			hsotg->op_state = OTG_STATE_A_PERIPHERAL;
242 		} else {
243 			/* Need to disable SOF interrupt immediately */
244 			gintmsk = readl(hsotg->regs + GINTMSK);
245 			gintmsk &= ~GINTSTS_SOF;
246 			writel(gintmsk, hsotg->regs + GINTMSK);
247 			spin_unlock(&hsotg->lock);
248 			dwc2_hcd_start(hsotg);
249 			spin_lock(&hsotg->lock);
250 			hsotg->op_state = OTG_STATE_A_HOST;
251 		}
252 	}
253 
254 	if (gotgint & GOTGINT_A_DEV_TOUT_CHG)
255 		dev_dbg(hsotg->dev,
256 			" ++OTG Interrupt: A-Device Timeout Change++\n");
257 	if (gotgint & GOTGINT_DBNCE_DONE)
258 		dev_dbg(hsotg->dev, " ++OTG Interrupt: Debounce Done++\n");
259 
260 	/* Clear GOTGINT */
261 	writel(gotgint, hsotg->regs + GOTGINT);
262 }
263 
264 /**
265  * dwc2_handle_conn_id_status_change_intr() - Handles the Connector ID Status
266  * Change Interrupt
267  *
268  * @hsotg: Programming view of DWC_otg controller
269  *
270  * Reads the OTG Interrupt Register (GOTCTL) to determine whether this is a
271  * Device to Host Mode transition or a Host to Device Mode transition. This only
272  * occurs when the cable is connected/removed from the PHY connector.
273  */
274 static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
275 {
276 	u32 gintmsk = readl(hsotg->regs + GINTMSK);
277 
278 	/* Need to disable SOF interrupt immediately */
279 	gintmsk &= ~GINTSTS_SOF;
280 	writel(gintmsk, hsotg->regs + GINTMSK);
281 
282 	dev_dbg(hsotg->dev, " ++Connector ID Status Change Interrupt++  (%s)\n",
283 		dwc2_is_host_mode(hsotg) ? "Host" : "Device");
284 
285 	/*
286 	 * Need to schedule a work, as there are possible DELAY function calls.
287 	 * Release lock before scheduling workq as it holds spinlock during
288 	 * scheduling.
289 	 */
290 	spin_unlock(&hsotg->lock);
291 	queue_work(hsotg->wq_otg, &hsotg->wf_otg);
292 	spin_lock(&hsotg->lock);
293 
294 	/* Clear interrupt */
295 	writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
296 }
297 
298 /**
299  * dwc2_handle_session_req_intr() - This interrupt indicates that a device is
300  * initiating the Session Request Protocol to request the host to turn on bus
301  * power so a new session can begin
302  *
303  * @hsotg: Programming view of DWC_otg controller
304  *
305  * This handler responds by turning on bus power. If the DWC_otg controller is
306  * in low power mode, this handler brings the controller out of low power mode
307  * before turning on bus power.
308  */
309 static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
310 {
311 	dev_dbg(hsotg->dev, "++Session Request Interrupt++\n");
312 
313 	/* Clear interrupt */
314 	writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);
315 }
316 
317 /*
318  * This interrupt indicates that the DWC_otg controller has detected a
319  * resume or remote wakeup sequence. If the DWC_otg controller is in
320  * low power mode, the handler must brings the controller out of low
321  * power mode. The controller automatically begins resume signaling.
322  * The handler schedules a time to stop resume signaling.
323  */
324 static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
325 {
326 	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
327 	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
328 
329 	if (dwc2_is_device_mode(hsotg)) {
330 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", readl(hsotg->regs + DSTS));
331 		if (hsotg->lx_state == DWC2_L2) {
332 			u32 dctl = readl(hsotg->regs + DCTL);
333 
334 			/* Clear Remote Wakeup Signaling */
335 			dctl &= ~DCTL_RMTWKUPSIG;
336 			writel(dctl, hsotg->regs + DCTL);
337 		}
338 		/* Change to L0 state */
339 		hsotg->lx_state = DWC2_L0;
340 	} else {
341 		if (hsotg->lx_state != DWC2_L1) {
342 			u32 pcgcctl = readl(hsotg->regs + PCGCTL);
343 
344 			/* Restart the Phy Clock */
345 			pcgcctl &= ~PCGCTL_STOPPCLK;
346 			writel(pcgcctl, hsotg->regs + PCGCTL);
347 			mod_timer(&hsotg->wkp_timer,
348 				  jiffies + msecs_to_jiffies(71));
349 		} else {
350 			/* Change to L0 state */
351 			hsotg->lx_state = DWC2_L0;
352 		}
353 	}
354 
355 	/* Clear interrupt */
356 	writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
357 }
358 
359 /*
360  * This interrupt indicates that a device has been disconnected from the
361  * root port
362  */
363 static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
364 {
365 	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
366 		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
367 		dwc2_op_state_str(hsotg));
368 
369 	/* Change to L3 (OFF) state */
370 	hsotg->lx_state = DWC2_L3;
371 
372 	writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
373 }
374 
375 /*
376  * This interrupt indicates that SUSPEND state has been detected on the USB.
377  *
378  * For HNP the USB Suspend interrupt signals the change from "a_peripheral"
379  * to "a_host".
380  *
381  * When power management is enabled the core will be put in low power mode.
382  */
383 static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
384 {
385 	u32 dsts;
386 
387 	dev_dbg(hsotg->dev, "USB SUSPEND\n");
388 
389 	if (dwc2_is_device_mode(hsotg)) {
390 		/*
391 		 * Check the Device status register to determine if the Suspend
392 		 * state is active
393 		 */
394 		dsts = readl(hsotg->regs + DSTS);
395 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", dsts);
396 		dev_dbg(hsotg->dev,
397 			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
398 			!!(dsts & DSTS_SUSPSTS),
399 			hsotg->hw_params.power_optimized);
400 	} else {
401 		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
402 			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
403 
404 			/* Clear the a_peripheral flag, back to a_host */
405 			spin_unlock(&hsotg->lock);
406 			dwc2_hcd_start(hsotg);
407 			spin_lock(&hsotg->lock);
408 			hsotg->op_state = OTG_STATE_A_HOST;
409 		}
410 	}
411 
412 	/* Change to L2 (suspend) state */
413 	hsotg->lx_state = DWC2_L2;
414 
415 	/* Clear interrupt */
416 	writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
417 }
418 
419 #define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
420 			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
421 			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
422 			 GINTSTS_USBSUSP | GINTSTS_PRTINT)
423 
424 /*
425  * This function returns the Core Interrupt register
426  */
427 static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
428 {
429 	u32 gintsts;
430 	u32 gintmsk;
431 	u32 gahbcfg;
432 	u32 gintmsk_common = GINTMSK_COMMON;
433 
434 	gintsts = readl(hsotg->regs + GINTSTS);
435 	gintmsk = readl(hsotg->regs + GINTMSK);
436 	gahbcfg = readl(hsotg->regs + GAHBCFG);
437 
438 	/* If any common interrupts set */
439 	if (gintsts & gintmsk_common)
440 		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
441 			gintsts, gintmsk);
442 
443 	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
444 		return gintsts & gintmsk & gintmsk_common;
445 	else
446 		return 0;
447 }
448 
449 /*
450  * Common interrupt handler
451  *
452  * The common interrupts are those that occur in both Host and Device mode.
453  * This handler handles the following interrupts:
454  * - Mode Mismatch Interrupt
455  * - OTG Interrupt
456  * - Connector ID Status Change Interrupt
457  * - Disconnect Interrupt
458  * - Session Request Interrupt
459  * - Resume / Remote Wakeup Detected Interrupt
460  * - Suspend Interrupt
461  */
462 irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
463 {
464 	struct dwc2_hsotg *hsotg = dev;
465 	u32 gintsts;
466 	irqreturn_t retval = IRQ_NONE;
467 
468 	if (!dwc2_is_controller_alive(hsotg)) {
469 		dev_warn(hsotg->dev, "Controller is dead\n");
470 		goto out;
471 	}
472 
473 	spin_lock(&hsotg->lock);
474 
475 	gintsts = dwc2_read_common_intr(hsotg);
476 	if (gintsts & ~GINTSTS_PRTINT)
477 		retval = IRQ_HANDLED;
478 
479 	if (gintsts & GINTSTS_MODEMIS)
480 		dwc2_handle_mode_mismatch_intr(hsotg);
481 	if (gintsts & GINTSTS_OTGINT)
482 		dwc2_handle_otg_intr(hsotg);
483 	if (gintsts & GINTSTS_CONIDSTSCHNG)
484 		dwc2_handle_conn_id_status_change_intr(hsotg);
485 	if (gintsts & GINTSTS_DISCONNINT)
486 		dwc2_handle_disconnect_intr(hsotg);
487 	if (gintsts & GINTSTS_SESSREQINT)
488 		dwc2_handle_session_req_intr(hsotg);
489 	if (gintsts & GINTSTS_WKUPINT)
490 		dwc2_handle_wakeup_detected_intr(hsotg);
491 	if (gintsts & GINTSTS_USBSUSP)
492 		dwc2_handle_usb_suspend_intr(hsotg);
493 
494 	if (gintsts & GINTSTS_PRTINT) {
495 		/*
496 		 * The port interrupt occurs while in device mode with HPRT0
497 		 * Port Enable/Disable
498 		 */
499 		if (dwc2_is_device_mode(hsotg)) {
500 			dev_dbg(hsotg->dev,
501 				" --Port interrupt received in Device mode--\n");
502 			dwc2_handle_usb_port_intr(hsotg);
503 			retval = IRQ_HANDLED;
504 		}
505 	}
506 
507 	spin_unlock(&hsotg->lock);
508 out:
509 	return retval;
510 }
511 EXPORT_SYMBOL_GPL(dwc2_handle_common_intr);
512