xref: /linux/drivers/usb/dwc2/core.c (revision 5c35a02c545a7bbe77f3a1ae337d9e29beed079b)
1 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2 /*
3  * core.c - DesignWare HS OTG Controller common routines
4  *
5  * Copyright (C) 2004-2013 Synopsys, Inc.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The names of the above-listed copyright holders may not be used
17  *    to endorse or promote products derived from this software without
18  *    specific prior written permission.
19  *
20  * ALTERNATIVELY, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") as published by the Free Software
22  * Foundation; either version 2 of the License, or (at your option) any
23  * later version.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
26  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
27  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * The Core code provides basic services for accessing and managing the
40  * DWC_otg hardware. These services are used by both the Host Controller
41  * Driver and the Peripheral Controller Driver.
42  */
43 #include <linux/kernel.h>
44 #include <linux/module.h>
45 #include <linux/moduleparam.h>
46 #include <linux/spinlock.h>
47 #include <linux/interrupt.h>
48 #include <linux/dma-mapping.h>
49 #include <linux/delay.h>
50 #include <linux/io.h>
51 #include <linux/slab.h>
52 #include <linux/usb.h>
53 
54 #include <linux/usb/hcd.h>
55 #include <linux/usb/ch11.h>
56 
57 #include "core.h"
58 #include "hcd.h"
59 
60 /**
61  * dwc2_backup_global_registers() - Backup global controller registers.
62  * When suspending usb bus, registers needs to be backuped
63  * if controller power is disabled once suspended.
64  *
65  * @hsotg: Programming view of the DWC_otg controller
66  */
67 int dwc2_backup_global_registers(struct dwc2_hsotg *hsotg)
68 {
69 	struct dwc2_gregs_backup *gr;
70 
71 	dev_dbg(hsotg->dev, "%s\n", __func__);
72 
73 	/* Backup global regs */
74 	gr = &hsotg->gr_backup;
75 
76 	gr->gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
77 	gr->gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
78 	gr->gahbcfg = dwc2_readl(hsotg->regs + GAHBCFG);
79 	gr->gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
80 	gr->grxfsiz = dwc2_readl(hsotg->regs + GRXFSIZ);
81 	gr->gnptxfsiz = dwc2_readl(hsotg->regs + GNPTXFSIZ);
82 	gr->gdfifocfg = dwc2_readl(hsotg->regs + GDFIFOCFG);
83 	gr->pcgcctl1 = dwc2_readl(hsotg->regs + PCGCCTL1);
84 	gr->glpmcfg = dwc2_readl(hsotg->regs + GLPMCFG);
85 	gr->gi2cctl = dwc2_readl(hsotg->regs + GI2CCTL);
86 	gr->pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
87 
88 	gr->valid = true;
89 	return 0;
90 }
91 
92 /**
93  * dwc2_restore_global_registers() - Restore controller global registers.
94  * When resuming usb bus, device registers needs to be restored
95  * if controller power were disabled.
96  *
97  * @hsotg: Programming view of the DWC_otg controller
98  */
99 int dwc2_restore_global_registers(struct dwc2_hsotg *hsotg)
100 {
101 	struct dwc2_gregs_backup *gr;
102 
103 	dev_dbg(hsotg->dev, "%s\n", __func__);
104 
105 	/* Restore global regs */
106 	gr = &hsotg->gr_backup;
107 	if (!gr->valid) {
108 		dev_err(hsotg->dev, "%s: no global registers to restore\n",
109 			__func__);
110 		return -EINVAL;
111 	}
112 	gr->valid = false;
113 
114 	dwc2_writel(0xffffffff, hsotg->regs + GINTSTS);
115 	dwc2_writel(gr->gotgctl, hsotg->regs + GOTGCTL);
116 	dwc2_writel(gr->gintmsk, hsotg->regs + GINTMSK);
117 	dwc2_writel(gr->gusbcfg, hsotg->regs + GUSBCFG);
118 	dwc2_writel(gr->gahbcfg, hsotg->regs + GAHBCFG);
119 	dwc2_writel(gr->grxfsiz, hsotg->regs + GRXFSIZ);
120 	dwc2_writel(gr->gnptxfsiz, hsotg->regs + GNPTXFSIZ);
121 	dwc2_writel(gr->gdfifocfg, hsotg->regs + GDFIFOCFG);
122 	dwc2_writel(gr->pcgcctl1, hsotg->regs + PCGCCTL1);
123 	dwc2_writel(gr->glpmcfg, hsotg->regs + GLPMCFG);
124 	dwc2_writel(gr->pcgcctl, hsotg->regs + PCGCTL);
125 	dwc2_writel(gr->gi2cctl, hsotg->regs + GI2CCTL);
126 
127 	return 0;
128 }
129 
130 /**
131  * dwc2_exit_partial_power_down() - Exit controller from Partial Power Down.
132  *
133  * @hsotg: Programming view of the DWC_otg controller
134  * @restore: Controller registers need to be restored
135  */
136 int dwc2_exit_partial_power_down(struct dwc2_hsotg *hsotg, bool restore)
137 {
138 	u32 pcgcctl;
139 	int ret = 0;
140 
141 	if (hsotg->params.power_down != DWC2_POWER_DOWN_PARAM_PARTIAL)
142 		return -ENOTSUPP;
143 
144 	pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
145 	pcgcctl &= ~PCGCTL_STOPPCLK;
146 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
147 
148 	pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
149 	pcgcctl &= ~PCGCTL_PWRCLMP;
150 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
151 
152 	pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
153 	pcgcctl &= ~PCGCTL_RSTPDWNMODULE;
154 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
155 
156 	udelay(100);
157 	if (restore) {
158 		ret = dwc2_restore_global_registers(hsotg);
159 		if (ret) {
160 			dev_err(hsotg->dev, "%s: failed to restore registers\n",
161 				__func__);
162 			return ret;
163 		}
164 		if (dwc2_is_host_mode(hsotg)) {
165 			ret = dwc2_restore_host_registers(hsotg);
166 			if (ret) {
167 				dev_err(hsotg->dev, "%s: failed to restore host registers\n",
168 					__func__);
169 				return ret;
170 			}
171 		} else {
172 			ret = dwc2_restore_device_registers(hsotg, 0);
173 			if (ret) {
174 				dev_err(hsotg->dev, "%s: failed to restore device registers\n",
175 					__func__);
176 				return ret;
177 			}
178 		}
179 	}
180 
181 	return ret;
182 }
183 
184 /**
185  * dwc2_enter_partial_power_down() - Put controller in Partial Power Down.
186  *
187  * @hsotg: Programming view of the DWC_otg controller
188  */
189 int dwc2_enter_partial_power_down(struct dwc2_hsotg *hsotg)
190 {
191 	u32 pcgcctl;
192 	int ret = 0;
193 
194 	if (!hsotg->params.power_down)
195 		return -ENOTSUPP;
196 
197 	/* Backup all registers */
198 	ret = dwc2_backup_global_registers(hsotg);
199 	if (ret) {
200 		dev_err(hsotg->dev, "%s: failed to backup global registers\n",
201 			__func__);
202 		return ret;
203 	}
204 
205 	if (dwc2_is_host_mode(hsotg)) {
206 		ret = dwc2_backup_host_registers(hsotg);
207 		if (ret) {
208 			dev_err(hsotg->dev, "%s: failed to backup host registers\n",
209 				__func__);
210 			return ret;
211 		}
212 	} else {
213 		ret = dwc2_backup_device_registers(hsotg);
214 		if (ret) {
215 			dev_err(hsotg->dev, "%s: failed to backup device registers\n",
216 				__func__);
217 			return ret;
218 		}
219 	}
220 
221 	/*
222 	 * Clear any pending interrupts since dwc2 will not be able to
223 	 * clear them after entering partial_power_down.
224 	 */
225 	dwc2_writel(0xffffffff, hsotg->regs + GINTSTS);
226 
227 	/* Put the controller in low power state */
228 	pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
229 
230 	pcgcctl |= PCGCTL_PWRCLMP;
231 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
232 	ndelay(20);
233 
234 	pcgcctl |= PCGCTL_RSTPDWNMODULE;
235 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
236 	ndelay(20);
237 
238 	pcgcctl |= PCGCTL_STOPPCLK;
239 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
240 
241 	return ret;
242 }
243 
244 /**
245  * dwc2_restore_essential_regs() - Restore essiential regs of core.
246  *
247  * @hsotg: Programming view of the DWC_otg controller
248  * @rmode: Restore mode, enabled in case of remote-wakeup.
249  * @is_host: Host or device mode.
250  */
251 static void dwc2_restore_essential_regs(struct dwc2_hsotg *hsotg, int rmode,
252 					int is_host)
253 {
254 	u32 pcgcctl;
255 	struct dwc2_gregs_backup *gr;
256 	struct dwc2_dregs_backup *dr;
257 	struct dwc2_hregs_backup *hr;
258 
259 	gr = &hsotg->gr_backup;
260 	dr = &hsotg->dr_backup;
261 	hr = &hsotg->hr_backup;
262 
263 	dev_dbg(hsotg->dev, "%s: restoring essential regs\n", __func__);
264 
265 	/* Load restore values for [31:14] bits */
266 	pcgcctl = (gr->pcgcctl & 0xffffc000);
267 	/* If High Speed */
268 	if (is_host) {
269 		if (!(pcgcctl & PCGCTL_P2HD_PRT_SPD_MASK))
270 			pcgcctl |= BIT(17);
271 	} else {
272 		if (!(pcgcctl & PCGCTL_P2HD_DEV_ENUM_SPD_MASK))
273 			pcgcctl |= BIT(17);
274 	}
275 	dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
276 
277 	/* Umnask global Interrupt in GAHBCFG and restore it */
278 	dwc2_writel(gr->gahbcfg | GAHBCFG_GLBL_INTR_EN, hsotg->regs + GAHBCFG);
279 
280 	/* Clear all pending interupts */
281 	dwc2_writel(0xffffffff, hsotg->regs + GINTSTS);
282 
283 	/* Unmask restore done interrupt */
284 	dwc2_writel(GINTSTS_RESTOREDONE, hsotg->regs + GINTMSK);
285 
286 	/* Restore GUSBCFG and HCFG/DCFG */
287 	dwc2_writel(gr->gusbcfg, hsotg->regs + GUSBCFG);
288 
289 	if (is_host) {
290 		dwc2_writel(hr->hcfg, hsotg->regs + HCFG);
291 		if (rmode)
292 			pcgcctl |= PCGCTL_RESTOREMODE;
293 		dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
294 		udelay(10);
295 
296 		pcgcctl |= PCGCTL_ESS_REG_RESTORED;
297 		dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
298 		udelay(10);
299 	} else {
300 		dwc2_writel(dr->dcfg, hsotg->regs + DCFG);
301 		if (!rmode)
302 			pcgcctl |= PCGCTL_RESTOREMODE | PCGCTL_RSTPDWNMODULE;
303 		dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
304 		udelay(10);
305 
306 		pcgcctl |= PCGCTL_ESS_REG_RESTORED;
307 		dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
308 		udelay(10);
309 	}
310 }
311 
312 /**
313  * dwc2_hib_restore_common() - Common part of restore routine.
314  *
315  * @hsotg: Programming view of the DWC_otg controller
316  * @rem_wakeup: Remote-wakeup, enabled in case of remote-wakeup.
317  * @is_host: Host or device mode.
318  */
319 void dwc2_hib_restore_common(struct dwc2_hsotg *hsotg, int rem_wakeup,
320 			     int is_host)
321 {
322 	u32 gpwrdn;
323 
324 	/* Switch-on voltage to the core */
325 	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
326 	gpwrdn &= ~GPWRDN_PWRDNSWTCH;
327 	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
328 	udelay(10);
329 
330 	/* Reset core */
331 	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
332 	gpwrdn &= ~GPWRDN_PWRDNRSTN;
333 	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
334 	udelay(10);
335 
336 	/* Enable restore from PMU */
337 	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
338 	gpwrdn |= GPWRDN_RESTORE;
339 	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
340 	udelay(10);
341 
342 	/* Disable Power Down Clamp */
343 	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
344 	gpwrdn &= ~GPWRDN_PWRDNCLMP;
345 	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
346 	udelay(50);
347 
348 	if (!is_host && rem_wakeup)
349 		udelay(70);
350 
351 	/* Deassert reset core */
352 	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
353 	gpwrdn |= GPWRDN_PWRDNRSTN;
354 	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
355 	udelay(10);
356 
357 	/* Disable PMU interrupt */
358 	gpwrdn = dwc2_readl(hsotg->regs + GPWRDN);
359 	gpwrdn &= ~GPWRDN_PMUINTSEL;
360 	dwc2_writel(gpwrdn, hsotg->regs + GPWRDN);
361 	udelay(10);
362 
363 	/* Set Restore Essential Regs bit in PCGCCTL register */
364 	dwc2_restore_essential_regs(hsotg, rem_wakeup, is_host);
365 
366 	/*
367 	 * Wait For Restore_done Interrupt. This mechanism of polling the
368 	 * interrupt is introduced to avoid any possible race conditions
369 	 */
370 	if (dwc2_hsotg_wait_bit_set(hsotg, GINTSTS, GINTSTS_RESTOREDONE,
371 				    20000)) {
372 		dev_dbg(hsotg->dev,
373 			"%s: Restore Done wan't generated here\n",
374 			__func__);
375 	} else {
376 		dev_dbg(hsotg->dev, "restore done  generated here\n");
377 	}
378 }
379 
380 /**
381  * dwc2_wait_for_mode() - Waits for the controller mode.
382  * @hsotg:	Programming view of the DWC_otg controller.
383  * @host_mode:	If true, waits for host mode, otherwise device mode.
384  */
385 static void dwc2_wait_for_mode(struct dwc2_hsotg *hsotg,
386 			       bool host_mode)
387 {
388 	ktime_t start;
389 	ktime_t end;
390 	unsigned int timeout = 110;
391 
392 	dev_vdbg(hsotg->dev, "Waiting for %s mode\n",
393 		 host_mode ? "host" : "device");
394 
395 	start = ktime_get();
396 
397 	while (1) {
398 		s64 ms;
399 
400 		if (dwc2_is_host_mode(hsotg) == host_mode) {
401 			dev_vdbg(hsotg->dev, "%s mode set\n",
402 				 host_mode ? "Host" : "Device");
403 			break;
404 		}
405 
406 		end = ktime_get();
407 		ms = ktime_to_ms(ktime_sub(end, start));
408 
409 		if (ms >= (s64)timeout) {
410 			dev_warn(hsotg->dev, "%s: Couldn't set %s mode\n",
411 				 __func__, host_mode ? "host" : "device");
412 			break;
413 		}
414 
415 		usleep_range(1000, 2000);
416 	}
417 }
418 
419 /**
420  * dwc2_iddig_filter_enabled() - Returns true if the IDDIG debounce
421  * filter is enabled.
422  *
423  * @hsotg: Programming view of DWC_otg controller
424  */
425 static bool dwc2_iddig_filter_enabled(struct dwc2_hsotg *hsotg)
426 {
427 	u32 gsnpsid;
428 	u32 ghwcfg4;
429 
430 	if (!dwc2_hw_is_otg(hsotg))
431 		return false;
432 
433 	/* Check if core configuration includes the IDDIG filter. */
434 	ghwcfg4 = dwc2_readl(hsotg->regs + GHWCFG4);
435 	if (!(ghwcfg4 & GHWCFG4_IDDIG_FILT_EN))
436 		return false;
437 
438 	/*
439 	 * Check if the IDDIG debounce filter is bypassed. Available
440 	 * in core version >= 3.10a.
441 	 */
442 	gsnpsid = dwc2_readl(hsotg->regs + GSNPSID);
443 	if (gsnpsid >= DWC2_CORE_REV_3_10a) {
444 		u32 gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
445 
446 		if (gotgctl & GOTGCTL_DBNCE_FLTR_BYPASS)
447 			return false;
448 	}
449 
450 	return true;
451 }
452 
453 /*
454  * dwc2_enter_hibernation() - Common function to enter hibernation.
455  *
456  * @hsotg: Programming view of the DWC_otg controller
457  * @is_host: True if core is in host mode.
458  *
459  * Return: 0 if successful, negative error code otherwise
460  */
461 int dwc2_enter_hibernation(struct dwc2_hsotg *hsotg, int is_host)
462 {
463 	if (hsotg->params.power_down != DWC2_POWER_DOWN_PARAM_HIBERNATION)
464 		return -ENOTSUPP;
465 
466 	if (is_host)
467 		return dwc2_host_enter_hibernation(hsotg);
468 	else
469 		return dwc2_gadget_enter_hibernation(hsotg);
470 }
471 
472 /*
473  * dwc2_exit_hibernation() - Common function to exit from hibernation.
474  *
475  * @hsotg: Programming view of the DWC_otg controller
476  * @rem_wakeup: Remote-wakeup, enabled in case of remote-wakeup.
477  * @reset: Enabled in case of restore with reset.
478  * @is_host: True if core is in host mode.
479  *
480  * Return: 0 if successful, negative error code otherwise
481  */
482 int dwc2_exit_hibernation(struct dwc2_hsotg *hsotg, int rem_wakeup,
483 			  int reset, int is_host)
484 {
485 	if (is_host)
486 		return dwc2_host_exit_hibernation(hsotg, rem_wakeup, reset);
487 	else
488 		return dwc2_gadget_exit_hibernation(hsotg, rem_wakeup, reset);
489 }
490 
491 /*
492  * Do core a soft reset of the core.  Be careful with this because it
493  * resets all the internal state machines of the core.
494  */
495 int dwc2_core_reset(struct dwc2_hsotg *hsotg, bool skip_wait)
496 {
497 	u32 greset;
498 	bool wait_for_host_mode = false;
499 
500 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
501 
502 	/*
503 	 * If the current mode is host, either due to the force mode
504 	 * bit being set (which persists after core reset) or the
505 	 * connector id pin, a core soft reset will temporarily reset
506 	 * the mode to device. A delay from the IDDIG debounce filter
507 	 * will occur before going back to host mode.
508 	 *
509 	 * Determine whether we will go back into host mode after a
510 	 * reset and account for this delay after the reset.
511 	 */
512 	if (dwc2_iddig_filter_enabled(hsotg)) {
513 		u32 gotgctl = dwc2_readl(hsotg->regs + GOTGCTL);
514 		u32 gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
515 
516 		if (!(gotgctl & GOTGCTL_CONID_B) ||
517 		    (gusbcfg & GUSBCFG_FORCEHOSTMODE)) {
518 			wait_for_host_mode = true;
519 		}
520 	}
521 
522 	/* Core Soft Reset */
523 	greset = dwc2_readl(hsotg->regs + GRSTCTL);
524 	greset |= GRSTCTL_CSFTRST;
525 	dwc2_writel(greset, hsotg->regs + GRSTCTL);
526 
527 	if (dwc2_hsotg_wait_bit_clear(hsotg, GRSTCTL, GRSTCTL_CSFTRST, 50)) {
528 		dev_warn(hsotg->dev, "%s: HANG! Soft Reset timeout GRSTCTL GRSTCTL_CSFTRST\n",
529 			 __func__);
530 		return -EBUSY;
531 	}
532 
533 	/* Wait for AHB master IDLE state */
534 	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 50)) {
535 		dev_warn(hsotg->dev, "%s: HANG! AHB Idle timeout GRSTCTL GRSTCTL_AHBIDLE\n",
536 			 __func__);
537 		return -EBUSY;
538 	}
539 
540 	if (wait_for_host_mode && !skip_wait)
541 		dwc2_wait_for_mode(hsotg, true);
542 
543 	return 0;
544 }
545 
546 /**
547  * dwc2_force_mode() - Force the mode of the controller.
548  *
549  * Forcing the mode is needed for two cases:
550  *
551  * 1) If the dr_mode is set to either HOST or PERIPHERAL we force the
552  * controller to stay in a particular mode regardless of ID pin
553  * changes. We do this once during probe.
554  *
555  * 2) During probe we want to read reset values of the hw
556  * configuration registers that are only available in either host or
557  * device mode. We may need to force the mode if the current mode does
558  * not allow us to access the register in the mode that we want.
559  *
560  * In either case it only makes sense to force the mode if the
561  * controller hardware is OTG capable.
562  *
563  * Checks are done in this function to determine whether doing a force
564  * would be valid or not.
565  *
566  * If a force is done, it requires a IDDIG debounce filter delay if
567  * the filter is configured and enabled. We poll the current mode of
568  * the controller to account for this delay.
569  *
570  * @hsotg: Programming view of DWC_otg controller
571  * @host: Host mode flag
572  */
573 void dwc2_force_mode(struct dwc2_hsotg *hsotg, bool host)
574 {
575 	u32 gusbcfg;
576 	u32 set;
577 	u32 clear;
578 
579 	dev_dbg(hsotg->dev, "Forcing mode to %s\n", host ? "host" : "device");
580 
581 	/*
582 	 * Force mode has no effect if the hardware is not OTG.
583 	 */
584 	if (!dwc2_hw_is_otg(hsotg))
585 		return;
586 
587 	/*
588 	 * If dr_mode is either peripheral or host only, there is no
589 	 * need to ever force the mode to the opposite mode.
590 	 */
591 	if (WARN_ON(host && hsotg->dr_mode == USB_DR_MODE_PERIPHERAL))
592 		return;
593 
594 	if (WARN_ON(!host && hsotg->dr_mode == USB_DR_MODE_HOST))
595 		return;
596 
597 	gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
598 
599 	set = host ? GUSBCFG_FORCEHOSTMODE : GUSBCFG_FORCEDEVMODE;
600 	clear = host ? GUSBCFG_FORCEDEVMODE : GUSBCFG_FORCEHOSTMODE;
601 
602 	gusbcfg &= ~clear;
603 	gusbcfg |= set;
604 	dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
605 
606 	dwc2_wait_for_mode(hsotg, host);
607 	return;
608 }
609 
610 /**
611  * dwc2_clear_force_mode() - Clears the force mode bits.
612  *
613  * After clearing the bits, wait up to 100 ms to account for any
614  * potential IDDIG filter delay. We can't know if we expect this delay
615  * or not because the value of the connector ID status is affected by
616  * the force mode. We only need to call this once during probe if
617  * dr_mode == OTG.
618  *
619  * @hsotg: Programming view of DWC_otg controller
620  */
621 static void dwc2_clear_force_mode(struct dwc2_hsotg *hsotg)
622 {
623 	u32 gusbcfg;
624 
625 	if (!dwc2_hw_is_otg(hsotg))
626 		return;
627 
628 	dev_dbg(hsotg->dev, "Clearing force mode bits\n");
629 
630 	gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
631 	gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
632 	gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
633 	dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
634 
635 	if (dwc2_iddig_filter_enabled(hsotg))
636 		msleep(100);
637 }
638 
639 /*
640  * Sets or clears force mode based on the dr_mode parameter.
641  */
642 void dwc2_force_dr_mode(struct dwc2_hsotg *hsotg)
643 {
644 	switch (hsotg->dr_mode) {
645 	case USB_DR_MODE_HOST:
646 		/*
647 		 * NOTE: This is required for some rockchip soc based
648 		 * platforms on their host-only dwc2.
649 		 */
650 		if (!dwc2_hw_is_otg(hsotg))
651 			msleep(50);
652 
653 		break;
654 	case USB_DR_MODE_PERIPHERAL:
655 		dwc2_force_mode(hsotg, false);
656 		break;
657 	case USB_DR_MODE_OTG:
658 		dwc2_clear_force_mode(hsotg);
659 		break;
660 	default:
661 		dev_warn(hsotg->dev, "%s() Invalid dr_mode=%d\n",
662 			 __func__, hsotg->dr_mode);
663 		break;
664 	}
665 }
666 
667 /*
668  * dwc2_enable_acg - enable active clock gating feature
669  */
670 void dwc2_enable_acg(struct dwc2_hsotg *hsotg)
671 {
672 	if (hsotg->params.acg_enable) {
673 		u32 pcgcctl1 = dwc2_readl(hsotg->regs + PCGCCTL1);
674 
675 		dev_dbg(hsotg->dev, "Enabling Active Clock Gating\n");
676 		pcgcctl1 |= PCGCCTL1_GATEEN;
677 		dwc2_writel(pcgcctl1, hsotg->regs + PCGCCTL1);
678 	}
679 }
680 
681 /**
682  * dwc2_dump_host_registers() - Prints the host registers
683  *
684  * @hsotg: Programming view of DWC_otg controller
685  *
686  * NOTE: This function will be removed once the peripheral controller code
687  * is integrated and the driver is stable
688  */
689 void dwc2_dump_host_registers(struct dwc2_hsotg *hsotg)
690 {
691 #ifdef DEBUG
692 	u32 __iomem *addr;
693 	int i;
694 
695 	dev_dbg(hsotg->dev, "Host Global Registers\n");
696 	addr = hsotg->regs + HCFG;
697 	dev_dbg(hsotg->dev, "HCFG	 @0x%08lX : 0x%08X\n",
698 		(unsigned long)addr, dwc2_readl(addr));
699 	addr = hsotg->regs + HFIR;
700 	dev_dbg(hsotg->dev, "HFIR	 @0x%08lX : 0x%08X\n",
701 		(unsigned long)addr, dwc2_readl(addr));
702 	addr = hsotg->regs + HFNUM;
703 	dev_dbg(hsotg->dev, "HFNUM	 @0x%08lX : 0x%08X\n",
704 		(unsigned long)addr, dwc2_readl(addr));
705 	addr = hsotg->regs + HPTXSTS;
706 	dev_dbg(hsotg->dev, "HPTXSTS	 @0x%08lX : 0x%08X\n",
707 		(unsigned long)addr, dwc2_readl(addr));
708 	addr = hsotg->regs + HAINT;
709 	dev_dbg(hsotg->dev, "HAINT	 @0x%08lX : 0x%08X\n",
710 		(unsigned long)addr, dwc2_readl(addr));
711 	addr = hsotg->regs + HAINTMSK;
712 	dev_dbg(hsotg->dev, "HAINTMSK	 @0x%08lX : 0x%08X\n",
713 		(unsigned long)addr, dwc2_readl(addr));
714 	if (hsotg->params.dma_desc_enable) {
715 		addr = hsotg->regs + HFLBADDR;
716 		dev_dbg(hsotg->dev, "HFLBADDR @0x%08lX : 0x%08X\n",
717 			(unsigned long)addr, dwc2_readl(addr));
718 	}
719 
720 	addr = hsotg->regs + HPRT0;
721 	dev_dbg(hsotg->dev, "HPRT0	 @0x%08lX : 0x%08X\n",
722 		(unsigned long)addr, dwc2_readl(addr));
723 
724 	for (i = 0; i < hsotg->params.host_channels; i++) {
725 		dev_dbg(hsotg->dev, "Host Channel %d Specific Registers\n", i);
726 		addr = hsotg->regs + HCCHAR(i);
727 		dev_dbg(hsotg->dev, "HCCHAR	 @0x%08lX : 0x%08X\n",
728 			(unsigned long)addr, dwc2_readl(addr));
729 		addr = hsotg->regs + HCSPLT(i);
730 		dev_dbg(hsotg->dev, "HCSPLT	 @0x%08lX : 0x%08X\n",
731 			(unsigned long)addr, dwc2_readl(addr));
732 		addr = hsotg->regs + HCINT(i);
733 		dev_dbg(hsotg->dev, "HCINT	 @0x%08lX : 0x%08X\n",
734 			(unsigned long)addr, dwc2_readl(addr));
735 		addr = hsotg->regs + HCINTMSK(i);
736 		dev_dbg(hsotg->dev, "HCINTMSK	 @0x%08lX : 0x%08X\n",
737 			(unsigned long)addr, dwc2_readl(addr));
738 		addr = hsotg->regs + HCTSIZ(i);
739 		dev_dbg(hsotg->dev, "HCTSIZ	 @0x%08lX : 0x%08X\n",
740 			(unsigned long)addr, dwc2_readl(addr));
741 		addr = hsotg->regs + HCDMA(i);
742 		dev_dbg(hsotg->dev, "HCDMA	 @0x%08lX : 0x%08X\n",
743 			(unsigned long)addr, dwc2_readl(addr));
744 		if (hsotg->params.dma_desc_enable) {
745 			addr = hsotg->regs + HCDMAB(i);
746 			dev_dbg(hsotg->dev, "HCDMAB	 @0x%08lX : 0x%08X\n",
747 				(unsigned long)addr, dwc2_readl(addr));
748 		}
749 	}
750 #endif
751 }
752 
753 /**
754  * dwc2_dump_global_registers() - Prints the core global registers
755  *
756  * @hsotg: Programming view of DWC_otg controller
757  *
758  * NOTE: This function will be removed once the peripheral controller code
759  * is integrated and the driver is stable
760  */
761 void dwc2_dump_global_registers(struct dwc2_hsotg *hsotg)
762 {
763 #ifdef DEBUG
764 	u32 __iomem *addr;
765 
766 	dev_dbg(hsotg->dev, "Core Global Registers\n");
767 	addr = hsotg->regs + GOTGCTL;
768 	dev_dbg(hsotg->dev, "GOTGCTL	 @0x%08lX : 0x%08X\n",
769 		(unsigned long)addr, dwc2_readl(addr));
770 	addr = hsotg->regs + GOTGINT;
771 	dev_dbg(hsotg->dev, "GOTGINT	 @0x%08lX : 0x%08X\n",
772 		(unsigned long)addr, dwc2_readl(addr));
773 	addr = hsotg->regs + GAHBCFG;
774 	dev_dbg(hsotg->dev, "GAHBCFG	 @0x%08lX : 0x%08X\n",
775 		(unsigned long)addr, dwc2_readl(addr));
776 	addr = hsotg->regs + GUSBCFG;
777 	dev_dbg(hsotg->dev, "GUSBCFG	 @0x%08lX : 0x%08X\n",
778 		(unsigned long)addr, dwc2_readl(addr));
779 	addr = hsotg->regs + GRSTCTL;
780 	dev_dbg(hsotg->dev, "GRSTCTL	 @0x%08lX : 0x%08X\n",
781 		(unsigned long)addr, dwc2_readl(addr));
782 	addr = hsotg->regs + GINTSTS;
783 	dev_dbg(hsotg->dev, "GINTSTS	 @0x%08lX : 0x%08X\n",
784 		(unsigned long)addr, dwc2_readl(addr));
785 	addr = hsotg->regs + GINTMSK;
786 	dev_dbg(hsotg->dev, "GINTMSK	 @0x%08lX : 0x%08X\n",
787 		(unsigned long)addr, dwc2_readl(addr));
788 	addr = hsotg->regs + GRXSTSR;
789 	dev_dbg(hsotg->dev, "GRXSTSR	 @0x%08lX : 0x%08X\n",
790 		(unsigned long)addr, dwc2_readl(addr));
791 	addr = hsotg->regs + GRXFSIZ;
792 	dev_dbg(hsotg->dev, "GRXFSIZ	 @0x%08lX : 0x%08X\n",
793 		(unsigned long)addr, dwc2_readl(addr));
794 	addr = hsotg->regs + GNPTXFSIZ;
795 	dev_dbg(hsotg->dev, "GNPTXFSIZ	 @0x%08lX : 0x%08X\n",
796 		(unsigned long)addr, dwc2_readl(addr));
797 	addr = hsotg->regs + GNPTXSTS;
798 	dev_dbg(hsotg->dev, "GNPTXSTS	 @0x%08lX : 0x%08X\n",
799 		(unsigned long)addr, dwc2_readl(addr));
800 	addr = hsotg->regs + GI2CCTL;
801 	dev_dbg(hsotg->dev, "GI2CCTL	 @0x%08lX : 0x%08X\n",
802 		(unsigned long)addr, dwc2_readl(addr));
803 	addr = hsotg->regs + GPVNDCTL;
804 	dev_dbg(hsotg->dev, "GPVNDCTL	 @0x%08lX : 0x%08X\n",
805 		(unsigned long)addr, dwc2_readl(addr));
806 	addr = hsotg->regs + GGPIO;
807 	dev_dbg(hsotg->dev, "GGPIO	 @0x%08lX : 0x%08X\n",
808 		(unsigned long)addr, dwc2_readl(addr));
809 	addr = hsotg->regs + GUID;
810 	dev_dbg(hsotg->dev, "GUID	 @0x%08lX : 0x%08X\n",
811 		(unsigned long)addr, dwc2_readl(addr));
812 	addr = hsotg->regs + GSNPSID;
813 	dev_dbg(hsotg->dev, "GSNPSID	 @0x%08lX : 0x%08X\n",
814 		(unsigned long)addr, dwc2_readl(addr));
815 	addr = hsotg->regs + GHWCFG1;
816 	dev_dbg(hsotg->dev, "GHWCFG1	 @0x%08lX : 0x%08X\n",
817 		(unsigned long)addr, dwc2_readl(addr));
818 	addr = hsotg->regs + GHWCFG2;
819 	dev_dbg(hsotg->dev, "GHWCFG2	 @0x%08lX : 0x%08X\n",
820 		(unsigned long)addr, dwc2_readl(addr));
821 	addr = hsotg->regs + GHWCFG3;
822 	dev_dbg(hsotg->dev, "GHWCFG3	 @0x%08lX : 0x%08X\n",
823 		(unsigned long)addr, dwc2_readl(addr));
824 	addr = hsotg->regs + GHWCFG4;
825 	dev_dbg(hsotg->dev, "GHWCFG4	 @0x%08lX : 0x%08X\n",
826 		(unsigned long)addr, dwc2_readl(addr));
827 	addr = hsotg->regs + GLPMCFG;
828 	dev_dbg(hsotg->dev, "GLPMCFG	 @0x%08lX : 0x%08X\n",
829 		(unsigned long)addr, dwc2_readl(addr));
830 	addr = hsotg->regs + GPWRDN;
831 	dev_dbg(hsotg->dev, "GPWRDN	 @0x%08lX : 0x%08X\n",
832 		(unsigned long)addr, dwc2_readl(addr));
833 	addr = hsotg->regs + GDFIFOCFG;
834 	dev_dbg(hsotg->dev, "GDFIFOCFG	 @0x%08lX : 0x%08X\n",
835 		(unsigned long)addr, dwc2_readl(addr));
836 	addr = hsotg->regs + HPTXFSIZ;
837 	dev_dbg(hsotg->dev, "HPTXFSIZ	 @0x%08lX : 0x%08X\n",
838 		(unsigned long)addr, dwc2_readl(addr));
839 
840 	addr = hsotg->regs + PCGCTL;
841 	dev_dbg(hsotg->dev, "PCGCTL	 @0x%08lX : 0x%08X\n",
842 		(unsigned long)addr, dwc2_readl(addr));
843 #endif
844 }
845 
846 /**
847  * dwc2_flush_tx_fifo() - Flushes a Tx FIFO
848  *
849  * @hsotg: Programming view of DWC_otg controller
850  * @num:   Tx FIFO to flush
851  */
852 void dwc2_flush_tx_fifo(struct dwc2_hsotg *hsotg, const int num)
853 {
854 	u32 greset;
855 
856 	dev_vdbg(hsotg->dev, "Flush Tx FIFO %d\n", num);
857 
858 	/* Wait for AHB master IDLE state */
859 	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 10000))
860 		dev_warn(hsotg->dev, "%s:  HANG! AHB Idle GRSCTL\n",
861 			 __func__);
862 
863 	greset = GRSTCTL_TXFFLSH;
864 	greset |= num << GRSTCTL_TXFNUM_SHIFT & GRSTCTL_TXFNUM_MASK;
865 	dwc2_writel(greset, hsotg->regs + GRSTCTL);
866 
867 	if (dwc2_hsotg_wait_bit_clear(hsotg, GRSTCTL, GRSTCTL_TXFFLSH, 10000))
868 		dev_warn(hsotg->dev, "%s:  HANG! timeout GRSTCTL GRSTCTL_TXFFLSH\n",
869 			 __func__);
870 
871 	/* Wait for at least 3 PHY Clocks */
872 	udelay(1);
873 }
874 
875 /**
876  * dwc2_flush_rx_fifo() - Flushes the Rx FIFO
877  *
878  * @hsotg: Programming view of DWC_otg controller
879  */
880 void dwc2_flush_rx_fifo(struct dwc2_hsotg *hsotg)
881 {
882 	u32 greset;
883 
884 	dev_vdbg(hsotg->dev, "%s()\n", __func__);
885 
886 	/* Wait for AHB master IDLE state */
887 	if (dwc2_hsotg_wait_bit_set(hsotg, GRSTCTL, GRSTCTL_AHBIDLE, 10000))
888 		dev_warn(hsotg->dev, "%s:  HANG! AHB Idle GRSCTL\n",
889 			 __func__);
890 
891 	greset = GRSTCTL_RXFFLSH;
892 	dwc2_writel(greset, hsotg->regs + GRSTCTL);
893 
894 	/* Wait for RxFIFO flush done */
895 	if (dwc2_hsotg_wait_bit_clear(hsotg, GRSTCTL, GRSTCTL_RXFFLSH, 10000))
896 		dev_warn(hsotg->dev, "%s: HANG! timeout GRSTCTL GRSTCTL_RXFFLSH\n",
897 			 __func__);
898 
899 	/* Wait for at least 3 PHY Clocks */
900 	udelay(1);
901 }
902 
903 bool dwc2_is_controller_alive(struct dwc2_hsotg *hsotg)
904 {
905 	if (dwc2_readl(hsotg->regs + GSNPSID) == 0xffffffff)
906 		return false;
907 	else
908 		return true;
909 }
910 
911 /**
912  * dwc2_enable_global_interrupts() - Enables the controller's Global
913  * Interrupt in the AHB Config register
914  *
915  * @hsotg: Programming view of DWC_otg controller
916  */
917 void dwc2_enable_global_interrupts(struct dwc2_hsotg *hsotg)
918 {
919 	u32 ahbcfg = dwc2_readl(hsotg->regs + GAHBCFG);
920 
921 	ahbcfg |= GAHBCFG_GLBL_INTR_EN;
922 	dwc2_writel(ahbcfg, hsotg->regs + GAHBCFG);
923 }
924 
925 /**
926  * dwc2_disable_global_interrupts() - Disables the controller's Global
927  * Interrupt in the AHB Config register
928  *
929  * @hsotg: Programming view of DWC_otg controller
930  */
931 void dwc2_disable_global_interrupts(struct dwc2_hsotg *hsotg)
932 {
933 	u32 ahbcfg = dwc2_readl(hsotg->regs + GAHBCFG);
934 
935 	ahbcfg &= ~GAHBCFG_GLBL_INTR_EN;
936 	dwc2_writel(ahbcfg, hsotg->regs + GAHBCFG);
937 }
938 
939 /* Returns the controller's GHWCFG2.OTG_MODE. */
940 unsigned int dwc2_op_mode(struct dwc2_hsotg *hsotg)
941 {
942 	u32 ghwcfg2 = dwc2_readl(hsotg->regs + GHWCFG2);
943 
944 	return (ghwcfg2 & GHWCFG2_OP_MODE_MASK) >>
945 		GHWCFG2_OP_MODE_SHIFT;
946 }
947 
948 /* Returns true if the controller is capable of DRD. */
949 bool dwc2_hw_is_otg(struct dwc2_hsotg *hsotg)
950 {
951 	unsigned int op_mode = dwc2_op_mode(hsotg);
952 
953 	return (op_mode == GHWCFG2_OP_MODE_HNP_SRP_CAPABLE) ||
954 		(op_mode == GHWCFG2_OP_MODE_SRP_ONLY_CAPABLE) ||
955 		(op_mode == GHWCFG2_OP_MODE_NO_HNP_SRP_CAPABLE);
956 }
957 
958 /* Returns true if the controller is host-only. */
959 bool dwc2_hw_is_host(struct dwc2_hsotg *hsotg)
960 {
961 	unsigned int op_mode = dwc2_op_mode(hsotg);
962 
963 	return (op_mode == GHWCFG2_OP_MODE_SRP_CAPABLE_HOST) ||
964 		(op_mode == GHWCFG2_OP_MODE_NO_SRP_CAPABLE_HOST);
965 }
966 
967 /* Returns true if the controller is device-only. */
968 bool dwc2_hw_is_device(struct dwc2_hsotg *hsotg)
969 {
970 	unsigned int op_mode = dwc2_op_mode(hsotg);
971 
972 	return (op_mode == GHWCFG2_OP_MODE_SRP_CAPABLE_DEVICE) ||
973 		(op_mode == GHWCFG2_OP_MODE_NO_SRP_CAPABLE_DEVICE);
974 }
975 
976 /**
977  * dwc2_hsotg_wait_bit_set - Waits for bit to be set.
978  * @hsotg: Programming view of DWC_otg controller.
979  * @offset: Register's offset where bit/bits must be set.
980  * @mask: Mask of the bit/bits which must be set.
981  * @timeout: Timeout to wait.
982  *
983  * Return: 0 if bit/bits are set or -ETIMEDOUT in case of timeout.
984  */
985 int dwc2_hsotg_wait_bit_set(struct dwc2_hsotg *hsotg, u32 offset, u32 mask,
986 			    u32 timeout)
987 {
988 	u32 i;
989 
990 	for (i = 0; i < timeout; i++) {
991 		if (dwc2_readl(hsotg->regs + offset) & mask)
992 			return 0;
993 		udelay(1);
994 	}
995 
996 	return -ETIMEDOUT;
997 }
998 
999 /**
1000  * dwc2_hsotg_wait_bit_clear - Waits for bit to be clear.
1001  * @hsotg: Programming view of DWC_otg controller.
1002  * @offset: Register's offset where bit/bits must be set.
1003  * @mask: Mask of the bit/bits which must be set.
1004  * @timeout: Timeout to wait.
1005  *
1006  * Return: 0 if bit/bits are set or -ETIMEDOUT in case of timeout.
1007  */
1008 int dwc2_hsotg_wait_bit_clear(struct dwc2_hsotg *hsotg, u32 offset, u32 mask,
1009 			      u32 timeout)
1010 {
1011 	u32 i;
1012 
1013 	for (i = 0; i < timeout; i++) {
1014 		if (!(dwc2_readl(hsotg->regs + offset) & mask))
1015 			return 0;
1016 		udelay(1);
1017 	}
1018 
1019 	return -ETIMEDOUT;
1020 }
1021 
1022 MODULE_DESCRIPTION("DESIGNWARE HS OTG Core");
1023 MODULE_AUTHOR("Synopsys, Inc.");
1024 MODULE_LICENSE("Dual BSD/GPL");
1025