xref: /openbmc/linux/drivers/usb/dwc2/core_intr.c (revision 94cdda6b)
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 (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  */
277 static 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  */
314 static 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  */
335 static 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  */
374 static 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  */
397 static 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  */
441 static 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  */
476 irqreturn_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 
521 out:
522 	spin_unlock(&hsotg->lock);
523 	return retval;
524 }
525 EXPORT_SYMBOL_GPL(dwc2_handle_common_intr);
526