xref: /openbmc/linux/drivers/usb/dwc2/core_intr.c (revision 8a10bc9d)
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_mode_mismatch_intr() - Logs a mode mismatch warning message
76  *
77  * @hsotg: Programming view of DWC_otg controller
78  */
79 static void dwc2_handle_mode_mismatch_intr(struct dwc2_hsotg *hsotg)
80 {
81 	dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
82 		 dwc2_is_host_mode(hsotg) ? "Host" : "Device");
83 
84 	/* Clear interrupt */
85 	writel(GINTSTS_MODEMIS, hsotg->regs + GINTSTS);
86 }
87 
88 /**
89  * dwc2_handle_otg_intr() - Handles the OTG Interrupts. It reads the OTG
90  * Interrupt Register (GOTGINT) to determine what interrupt has occurred.
91  *
92  * @hsotg: Programming view of DWC_otg controller
93  */
94 static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg)
95 {
96 	u32 gotgint;
97 	u32 gotgctl;
98 	u32 gintmsk;
99 
100 	gotgint = readl(hsotg->regs + GOTGINT);
101 	gotgctl = readl(hsotg->regs + GOTGCTL);
102 	dev_dbg(hsotg->dev, "++OTG Interrupt gotgint=%0x [%s]\n", gotgint,
103 		dwc2_op_state_str(hsotg));
104 
105 	if (gotgint & GOTGINT_SES_END_DET) {
106 		dev_dbg(hsotg->dev,
107 			" ++OTG Interrupt: Session End Detected++ (%s)\n",
108 			dwc2_op_state_str(hsotg));
109 		gotgctl = readl(hsotg->regs + GOTGCTL);
110 
111 		if (hsotg->op_state == OTG_STATE_B_HOST) {
112 			hsotg->op_state = OTG_STATE_B_PERIPHERAL;
113 		} else {
114 			/*
115 			 * If not B_HOST and Device HNP still set, HNP did
116 			 * not succeed!
117 			 */
118 			if (gotgctl & GOTGCTL_DEVHNPEN) {
119 				dev_dbg(hsotg->dev, "Session End Detected\n");
120 				dev_err(hsotg->dev,
121 					"Device Not Connected/Responding!\n");
122 			}
123 
124 			/*
125 			 * If Session End Detected the B-Cable has been
126 			 * disconnected
127 			 */
128 			/* Reset to a clean state */
129 			hsotg->lx_state = DWC2_L0;
130 		}
131 
132 		gotgctl = readl(hsotg->regs + GOTGCTL);
133 		gotgctl &= ~GOTGCTL_DEVHNPEN;
134 		writel(gotgctl, hsotg->regs + GOTGCTL);
135 	}
136 
137 	if (gotgint & GOTGINT_SES_REQ_SUC_STS_CHNG) {
138 		dev_dbg(hsotg->dev,
139 			" ++OTG Interrupt: Session Request Success Status Change++\n");
140 		gotgctl = readl(hsotg->regs + GOTGCTL);
141 		if (gotgctl & GOTGCTL_SESREQSCS) {
142 			if (hsotg->core_params->phy_type ==
143 					DWC2_PHY_TYPE_PARAM_FS
144 			    && hsotg->core_params->i2c_enable > 0) {
145 				hsotg->srp_success = 1;
146 			} else {
147 				/* Clear Session Request */
148 				gotgctl = readl(hsotg->regs + GOTGCTL);
149 				gotgctl &= ~GOTGCTL_SESREQ;
150 				writel(gotgctl, hsotg->regs + GOTGCTL);
151 			}
152 		}
153 	}
154 
155 	if (gotgint & GOTGINT_HST_NEG_SUC_STS_CHNG) {
156 		/*
157 		 * Print statements during the HNP interrupt handling
158 		 * can cause it to fail
159 		 */
160 		gotgctl = readl(hsotg->regs + GOTGCTL);
161 		/*
162 		 * WA for 3.00a- HW is not setting cur_mode, even sometimes
163 		 * this does not help
164 		 */
165 		if (hsotg->hw_params.snpsid >= DWC2_CORE_REV_3_00a)
166 			udelay(100);
167 		if (gotgctl & GOTGCTL_HSTNEGSCS) {
168 			if (dwc2_is_host_mode(hsotg)) {
169 				hsotg->op_state = OTG_STATE_B_HOST;
170 				/*
171 				 * Need to disable SOF interrupt immediately.
172 				 * When switching from device to host, the PCD
173 				 * interrupt handler won't handle the interrupt
174 				 * if host mode is already set. The HCD
175 				 * interrupt handler won't get called if the
176 				 * HCD state is HALT. This means that the
177 				 * interrupt does not get handled and Linux
178 				 * complains loudly.
179 				 */
180 				gintmsk = readl(hsotg->regs + GINTMSK);
181 				gintmsk &= ~GINTSTS_SOF;
182 				writel(gintmsk, hsotg->regs + GINTMSK);
183 
184 				/*
185 				 * Call callback function with spin lock
186 				 * released
187 				 */
188 				spin_unlock(&hsotg->lock);
189 
190 				/* Initialize the Core for Host mode */
191 				dwc2_hcd_start(hsotg);
192 				spin_lock(&hsotg->lock);
193 				hsotg->op_state = OTG_STATE_B_HOST;
194 			}
195 		} else {
196 			gotgctl = readl(hsotg->regs + GOTGCTL);
197 			gotgctl &= ~(GOTGCTL_HNPREQ | GOTGCTL_DEVHNPEN);
198 			writel(gotgctl, hsotg->regs + GOTGCTL);
199 			dev_dbg(hsotg->dev, "HNP Failed\n");
200 			dev_err(hsotg->dev,
201 				"Device Not Connected/Responding\n");
202 		}
203 	}
204 
205 	if (gotgint & GOTGINT_HST_NEG_DET) {
206 		/*
207 		 * The disconnect interrupt is set at the same time as
208 		 * Host Negotiation Detected. During the mode switch all
209 		 * interrupts are cleared so the disconnect interrupt
210 		 * handler will not get executed.
211 		 */
212 		dev_dbg(hsotg->dev,
213 			" ++OTG Interrupt: Host Negotiation Detected++ (%s)\n",
214 			(dwc2_is_host_mode(hsotg) ? "Host" : "Device"));
215 		if (dwc2_is_device_mode(hsotg)) {
216 			dev_dbg(hsotg->dev, "a_suspend->a_peripheral (%d)\n",
217 				hsotg->op_state);
218 			spin_unlock(&hsotg->lock);
219 			dwc2_hcd_disconnect(hsotg);
220 			spin_lock(&hsotg->lock);
221 			hsotg->op_state = OTG_STATE_A_PERIPHERAL;
222 		} else {
223 			/* Need to disable SOF interrupt immediately */
224 			gintmsk = readl(hsotg->regs + GINTMSK);
225 			gintmsk &= ~GINTSTS_SOF;
226 			writel(gintmsk, hsotg->regs + GINTMSK);
227 			spin_unlock(&hsotg->lock);
228 			dwc2_hcd_start(hsotg);
229 			spin_lock(&hsotg->lock);
230 			hsotg->op_state = OTG_STATE_A_HOST;
231 		}
232 	}
233 
234 	if (gotgint & GOTGINT_A_DEV_TOUT_CHG)
235 		dev_dbg(hsotg->dev,
236 			" ++OTG Interrupt: A-Device Timeout Change++\n");
237 	if (gotgint & GOTGINT_DBNCE_DONE)
238 		dev_dbg(hsotg->dev, " ++OTG Interrupt: Debounce Done++\n");
239 
240 	/* Clear GOTGINT */
241 	writel(gotgint, hsotg->regs + GOTGINT);
242 }
243 
244 /**
245  * dwc2_handle_conn_id_status_change_intr() - Handles the Connector ID Status
246  * Change Interrupt
247  *
248  * @hsotg: Programming view of DWC_otg controller
249  *
250  * Reads the OTG Interrupt Register (GOTCTL) to determine whether this is a
251  * Device to Host Mode transition or a Host to Device Mode transition. This only
252  * occurs when the cable is connected/removed from the PHY connector.
253  */
254 static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
255 {
256 	u32 gintmsk = readl(hsotg->regs + GINTMSK);
257 
258 	/* Need to disable SOF interrupt immediately */
259 	gintmsk &= ~GINTSTS_SOF;
260 	writel(gintmsk, hsotg->regs + GINTMSK);
261 
262 	dev_dbg(hsotg->dev, " ++Connector ID Status Change Interrupt++  (%s)\n",
263 		dwc2_is_host_mode(hsotg) ? "Host" : "Device");
264 
265 	/*
266 	 * Need to schedule a work, as there are possible DELAY function calls.
267 	 * Release lock before scheduling workq as it holds spinlock during
268 	 * scheduling.
269 	 */
270 	spin_unlock(&hsotg->lock);
271 	queue_work(hsotg->wq_otg, &hsotg->wf_otg);
272 	spin_lock(&hsotg->lock);
273 
274 	/* Clear interrupt */
275 	writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
276 }
277 
278 /**
279  * dwc2_handle_session_req_intr() - This interrupt indicates that a device is
280  * initiating the Session Request Protocol to request the host to turn on bus
281  * power so a new session can begin
282  *
283  * @hsotg: Programming view of DWC_otg controller
284  *
285  * This handler responds by turning on bus power. If the DWC_otg controller is
286  * in low power mode, this handler brings the controller out of low power mode
287  * before turning on bus power.
288  */
289 static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
290 {
291 	dev_dbg(hsotg->dev, "++Session Request Interrupt++\n");
292 
293 	/* Clear interrupt */
294 	writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);
295 }
296 
297 /*
298  * This interrupt indicates that the DWC_otg controller has detected a
299  * resume or remote wakeup sequence. If the DWC_otg controller is in
300  * low power mode, the handler must brings the controller out of low
301  * power mode. The controller automatically begins resume signaling.
302  * The handler schedules a time to stop resume signaling.
303  */
304 static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
305 {
306 	dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
307 	dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
308 
309 	if (dwc2_is_device_mode(hsotg)) {
310 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", readl(hsotg->regs + DSTS));
311 		if (hsotg->lx_state == DWC2_L2) {
312 			u32 dctl = readl(hsotg->regs + DCTL);
313 
314 			/* Clear Remote Wakeup Signaling */
315 			dctl &= ~DCTL_RMTWKUPSIG;
316 			writel(dctl, hsotg->regs + DCTL);
317 		}
318 		/* Change to L0 state */
319 		hsotg->lx_state = DWC2_L0;
320 	} else {
321 		if (hsotg->lx_state != DWC2_L1) {
322 			u32 pcgcctl = readl(hsotg->regs + PCGCTL);
323 
324 			/* Restart the Phy Clock */
325 			pcgcctl &= ~PCGCTL_STOPPCLK;
326 			writel(pcgcctl, hsotg->regs + PCGCTL);
327 			mod_timer(&hsotg->wkp_timer,
328 				  jiffies + msecs_to_jiffies(71));
329 		} else {
330 			/* Change to L0 state */
331 			hsotg->lx_state = DWC2_L0;
332 		}
333 	}
334 
335 	/* Clear interrupt */
336 	writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
337 }
338 
339 /*
340  * This interrupt indicates that a device has been disconnected from the
341  * root port
342  */
343 static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
344 {
345 	dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
346 		dwc2_is_host_mode(hsotg) ? "Host" : "Device",
347 		dwc2_op_state_str(hsotg));
348 
349 	/* Change to L3 (OFF) state */
350 	hsotg->lx_state = DWC2_L3;
351 
352 	writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
353 }
354 
355 /*
356  * This interrupt indicates that SUSPEND state has been detected on the USB.
357  *
358  * For HNP the USB Suspend interrupt signals the change from "a_peripheral"
359  * to "a_host".
360  *
361  * When power management is enabled the core will be put in low power mode.
362  */
363 static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
364 {
365 	u32 dsts;
366 
367 	dev_dbg(hsotg->dev, "USB SUSPEND\n");
368 
369 	if (dwc2_is_device_mode(hsotg)) {
370 		/*
371 		 * Check the Device status register to determine if the Suspend
372 		 * state is active
373 		 */
374 		dsts = readl(hsotg->regs + DSTS);
375 		dev_dbg(hsotg->dev, "DSTS=0x%0x\n", dsts);
376 		dev_dbg(hsotg->dev,
377 			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
378 			!!(dsts & DSTS_SUSPSTS),
379 			hsotg->hw_params.power_optimized);
380 	} else {
381 		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
382 			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
383 
384 			/* Clear the a_peripheral flag, back to a_host */
385 			spin_unlock(&hsotg->lock);
386 			dwc2_hcd_start(hsotg);
387 			spin_lock(&hsotg->lock);
388 			hsotg->op_state = OTG_STATE_A_HOST;
389 		}
390 	}
391 
392 	/* Change to L2 (suspend) state */
393 	hsotg->lx_state = DWC2_L2;
394 
395 	/* Clear interrupt */
396 	writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
397 }
398 
399 #define GINTMSK_COMMON	(GINTSTS_WKUPINT | GINTSTS_SESSREQINT |		\
400 			 GINTSTS_CONIDSTSCHNG | GINTSTS_OTGINT |	\
401 			 GINTSTS_MODEMIS | GINTSTS_DISCONNINT |		\
402 			 GINTSTS_USBSUSP | GINTSTS_PRTINT)
403 
404 /*
405  * This function returns the Core Interrupt register
406  */
407 static u32 dwc2_read_common_intr(struct dwc2_hsotg *hsotg)
408 {
409 	u32 gintsts;
410 	u32 gintmsk;
411 	u32 gahbcfg;
412 	u32 gintmsk_common = GINTMSK_COMMON;
413 
414 	gintsts = readl(hsotg->regs + GINTSTS);
415 	gintmsk = readl(hsotg->regs + GINTMSK);
416 	gahbcfg = readl(hsotg->regs + GAHBCFG);
417 
418 	/* If any common interrupts set */
419 	if (gintsts & gintmsk_common)
420 		dev_dbg(hsotg->dev, "gintsts=%08x  gintmsk=%08x\n",
421 			gintsts, gintmsk);
422 
423 	if (gahbcfg & GAHBCFG_GLBL_INTR_EN)
424 		return gintsts & gintmsk & gintmsk_common;
425 	else
426 		return 0;
427 }
428 
429 /*
430  * Common interrupt handler
431  *
432  * The common interrupts are those that occur in both Host and Device mode.
433  * This handler handles the following interrupts:
434  * - Mode Mismatch Interrupt
435  * - OTG Interrupt
436  * - Connector ID Status Change Interrupt
437  * - Disconnect Interrupt
438  * - Session Request Interrupt
439  * - Resume / Remote Wakeup Detected Interrupt
440  * - Suspend Interrupt
441  */
442 irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
443 {
444 	struct dwc2_hsotg *hsotg = dev;
445 	u32 gintsts;
446 	irqreturn_t retval = IRQ_NONE;
447 
448 	if (!dwc2_is_controller_alive(hsotg)) {
449 		dev_warn(hsotg->dev, "Controller is dead\n");
450 		goto out;
451 	}
452 
453 	spin_lock(&hsotg->lock);
454 
455 	gintsts = dwc2_read_common_intr(hsotg);
456 	if (gintsts & ~GINTSTS_PRTINT)
457 		retval = IRQ_HANDLED;
458 
459 	if (gintsts & GINTSTS_MODEMIS)
460 		dwc2_handle_mode_mismatch_intr(hsotg);
461 	if (gintsts & GINTSTS_OTGINT)
462 		dwc2_handle_otg_intr(hsotg);
463 	if (gintsts & GINTSTS_CONIDSTSCHNG)
464 		dwc2_handle_conn_id_status_change_intr(hsotg);
465 	if (gintsts & GINTSTS_DISCONNINT)
466 		dwc2_handle_disconnect_intr(hsotg);
467 	if (gintsts & GINTSTS_SESSREQINT)
468 		dwc2_handle_session_req_intr(hsotg);
469 	if (gintsts & GINTSTS_WKUPINT)
470 		dwc2_handle_wakeup_detected_intr(hsotg);
471 	if (gintsts & GINTSTS_USBSUSP)
472 		dwc2_handle_usb_suspend_intr(hsotg);
473 
474 	if (gintsts & GINTSTS_PRTINT) {
475 		/*
476 		 * The port interrupt occurs while in device mode with HPRT0
477 		 * Port Enable/Disable
478 		 */
479 		if (dwc2_is_device_mode(hsotg)) {
480 			dev_dbg(hsotg->dev,
481 				" --Port interrupt received in Device mode--\n");
482 			gintsts = GINTSTS_PRTINT;
483 			writel(gintsts, hsotg->regs + GINTSTS);
484 			retval = 1;
485 		}
486 	}
487 
488 	spin_unlock(&hsotg->lock);
489 out:
490 	return retval;
491 }
492 EXPORT_SYMBOL_GPL(dwc2_handle_common_intr);
493