1// SPDX-License-Identifier: GPL-2.0
2/*
3 * otg_fsm.c - ChipIdea USB IP core OTG FSM driver
4 *
5 * Copyright (C) 2014 Freescale Semiconductor, Inc.
6 *
7 * Author: Jun Li
8 */
9
10/*
11 * This file mainly handles OTG fsm, it includes OTG fsm operations
12 * for HNP and SRP.
13 *
14 * TODO List
15 * - ADP
16 * - OTG test device
17 */
18
19#include <linux/usb/otg.h>
20#include <linux/usb/gadget.h>
21#include <linux/usb/hcd.h>
22#include <linux/usb/chipidea.h>
23#include <linux/regulator/consumer.h>
24
25#include "ci.h"
26#include "bits.h"
27#include "otg.h"
28#include "otg_fsm.h"
29
30/* Add for otg: interact with user space app */
31static ssize_t
32a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
33{
34 char *next;
35 unsigned size, t;
36 struct ci_hdrc *ci = dev_get_drvdata(dev);
37
38 next = buf;
39 size = PAGE_SIZE;
40 t = scnprintf(buf: next, size, fmt: "%d\n", ci->fsm.a_bus_req);
41 size -= t;
42 next += t;
43
44 return PAGE_SIZE - size;
45}
46
47static ssize_t
48a_bus_req_store(struct device *dev, struct device_attribute *attr,
49 const char *buf, size_t count)
50{
51 struct ci_hdrc *ci = dev_get_drvdata(dev);
52
53 if (count > 2)
54 return -1;
55
56 mutex_lock(&ci->fsm.lock);
57 if (buf[0] == '0') {
58 ci->fsm.a_bus_req = 0;
59 } else if (buf[0] == '1') {
60 /* If a_bus_drop is TRUE, a_bus_req can't be set */
61 if (ci->fsm.a_bus_drop) {
62 mutex_unlock(lock: &ci->fsm.lock);
63 return count;
64 }
65 ci->fsm.a_bus_req = 1;
66 if (ci->fsm.otg->state == OTG_STATE_A_PERIPHERAL) {
67 ci->gadget.host_request_flag = 1;
68 mutex_unlock(lock: &ci->fsm.lock);
69 return count;
70 }
71 }
72
73 ci_otg_queue_work(ci);
74 mutex_unlock(lock: &ci->fsm.lock);
75
76 return count;
77}
78static DEVICE_ATTR_RW(a_bus_req);
79
80static ssize_t
81a_bus_drop_show(struct device *dev, struct device_attribute *attr, char *buf)
82{
83 char *next;
84 unsigned size, t;
85 struct ci_hdrc *ci = dev_get_drvdata(dev);
86
87 next = buf;
88 size = PAGE_SIZE;
89 t = scnprintf(buf: next, size, fmt: "%d\n", ci->fsm.a_bus_drop);
90 size -= t;
91 next += t;
92
93 return PAGE_SIZE - size;
94}
95
96static ssize_t
97a_bus_drop_store(struct device *dev, struct device_attribute *attr,
98 const char *buf, size_t count)
99{
100 struct ci_hdrc *ci = dev_get_drvdata(dev);
101
102 if (count > 2)
103 return -1;
104
105 mutex_lock(&ci->fsm.lock);
106 if (buf[0] == '0') {
107 ci->fsm.a_bus_drop = 0;
108 } else if (buf[0] == '1') {
109 ci->fsm.a_bus_drop = 1;
110 ci->fsm.a_bus_req = 0;
111 }
112
113 ci_otg_queue_work(ci);
114 mutex_unlock(lock: &ci->fsm.lock);
115
116 return count;
117}
118static DEVICE_ATTR_RW(a_bus_drop);
119
120static ssize_t
121b_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
122{
123 char *next;
124 unsigned size, t;
125 struct ci_hdrc *ci = dev_get_drvdata(dev);
126
127 next = buf;
128 size = PAGE_SIZE;
129 t = scnprintf(buf: next, size, fmt: "%d\n", ci->fsm.b_bus_req);
130 size -= t;
131 next += t;
132
133 return PAGE_SIZE - size;
134}
135
136static ssize_t
137b_bus_req_store(struct device *dev, struct device_attribute *attr,
138 const char *buf, size_t count)
139{
140 struct ci_hdrc *ci = dev_get_drvdata(dev);
141
142 if (count > 2)
143 return -1;
144
145 mutex_lock(&ci->fsm.lock);
146 if (buf[0] == '0')
147 ci->fsm.b_bus_req = 0;
148 else if (buf[0] == '1') {
149 ci->fsm.b_bus_req = 1;
150 if (ci->fsm.otg->state == OTG_STATE_B_PERIPHERAL) {
151 ci->gadget.host_request_flag = 1;
152 mutex_unlock(lock: &ci->fsm.lock);
153 return count;
154 }
155 }
156
157 ci_otg_queue_work(ci);
158 mutex_unlock(lock: &ci->fsm.lock);
159
160 return count;
161}
162static DEVICE_ATTR_RW(b_bus_req);
163
164static ssize_t
165a_clr_err_store(struct device *dev, struct device_attribute *attr,
166 const char *buf, size_t count)
167{
168 struct ci_hdrc *ci = dev_get_drvdata(dev);
169
170 if (count > 2)
171 return -1;
172
173 mutex_lock(&ci->fsm.lock);
174 if (buf[0] == '1')
175 ci->fsm.a_clr_err = 1;
176
177 ci_otg_queue_work(ci);
178 mutex_unlock(lock: &ci->fsm.lock);
179
180 return count;
181}
182static DEVICE_ATTR_WO(a_clr_err);
183
184static struct attribute *inputs_attrs[] = {
185 &dev_attr_a_bus_req.attr,
186 &dev_attr_a_bus_drop.attr,
187 &dev_attr_b_bus_req.attr,
188 &dev_attr_a_clr_err.attr,
189 NULL,
190};
191
192static const struct attribute_group inputs_attr_group = {
193 .name = "inputs",
194 .attrs = inputs_attrs,
195};
196
197/*
198 * Keep this list in the same order as timers indexed
199 * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
200 */
201static unsigned otg_timer_ms[] = {
202 TA_WAIT_VRISE,
203 TA_WAIT_VFALL,
204 TA_WAIT_BCON,
205 TA_AIDL_BDIS,
206 TB_ASE0_BRST,
207 TA_BIDL_ADIS,
208 TB_AIDL_BDIS,
209 TB_SE0_SRP,
210 TB_SRP_FAIL,
211 0,
212 TB_DATA_PLS,
213 TB_SSEND_SRP,
214};
215
216/*
217 * Add timer to active timer list
218 */
219static void ci_otg_add_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
220{
221 unsigned long flags, timer_sec, timer_nsec;
222
223 if (t >= NUM_OTG_FSM_TIMERS)
224 return;
225
226 spin_lock_irqsave(&ci->lock, flags);
227 timer_sec = otg_timer_ms[t] / MSEC_PER_SEC;
228 timer_nsec = (otg_timer_ms[t] % MSEC_PER_SEC) * NSEC_PER_MSEC;
229 ci->hr_timeouts[t] = ktime_add(ktime_get(),
230 ktime_set(timer_sec, timer_nsec));
231 ci->enabled_otg_timer_bits |= (1 << t);
232 if ((ci->next_otg_timer == NUM_OTG_FSM_TIMERS) ||
233 ktime_after(cmp1: ci->hr_timeouts[ci->next_otg_timer],
234 cmp2: ci->hr_timeouts[t])) {
235 ci->next_otg_timer = t;
236 hrtimer_start_range_ns(timer: &ci->otg_fsm_hrtimer,
237 tim: ci->hr_timeouts[t], NSEC_PER_MSEC,
238 mode: HRTIMER_MODE_ABS);
239 }
240 spin_unlock_irqrestore(lock: &ci->lock, flags);
241}
242
243/*
244 * Remove timer from active timer list
245 */
246static void ci_otg_del_timer(struct ci_hdrc *ci, enum otg_fsm_timer t)
247{
248 unsigned long flags, enabled_timer_bits;
249 enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
250
251 if ((t >= NUM_OTG_FSM_TIMERS) ||
252 !(ci->enabled_otg_timer_bits & (1 << t)))
253 return;
254
255 spin_lock_irqsave(&ci->lock, flags);
256 ci->enabled_otg_timer_bits &= ~(1 << t);
257 if (ci->next_otg_timer == t) {
258 if (ci->enabled_otg_timer_bits == 0) {
259 spin_unlock_irqrestore(lock: &ci->lock, flags);
260 /* No enabled timers after delete it */
261 hrtimer_cancel(timer: &ci->otg_fsm_hrtimer);
262 spin_lock_irqsave(&ci->lock, flags);
263 ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
264 } else {
265 /* Find the next timer */
266 enabled_timer_bits = ci->enabled_otg_timer_bits;
267 for_each_set_bit(cur_timer, &enabled_timer_bits,
268 NUM_OTG_FSM_TIMERS) {
269 if ((next_timer == NUM_OTG_FSM_TIMERS) ||
270 ktime_before(cmp1: ci->hr_timeouts[next_timer],
271 cmp2: ci->hr_timeouts[cur_timer]))
272 next_timer = cur_timer;
273 }
274 }
275 }
276 if (next_timer != NUM_OTG_FSM_TIMERS) {
277 ci->next_otg_timer = next_timer;
278 hrtimer_start_range_ns(timer: &ci->otg_fsm_hrtimer,
279 tim: ci->hr_timeouts[next_timer], NSEC_PER_MSEC,
280 mode: HRTIMER_MODE_ABS);
281 }
282 spin_unlock_irqrestore(lock: &ci->lock, flags);
283}
284
285/* OTG FSM timer handlers */
286static int a_wait_vrise_tmout(struct ci_hdrc *ci)
287{
288 ci->fsm.a_wait_vrise_tmout = 1;
289 return 0;
290}
291
292static int a_wait_vfall_tmout(struct ci_hdrc *ci)
293{
294 ci->fsm.a_wait_vfall_tmout = 1;
295 return 0;
296}
297
298static int a_wait_bcon_tmout(struct ci_hdrc *ci)
299{
300 ci->fsm.a_wait_bcon_tmout = 1;
301 return 0;
302}
303
304static int a_aidl_bdis_tmout(struct ci_hdrc *ci)
305{
306 ci->fsm.a_aidl_bdis_tmout = 1;
307 return 0;
308}
309
310static int b_ase0_brst_tmout(struct ci_hdrc *ci)
311{
312 ci->fsm.b_ase0_brst_tmout = 1;
313 return 0;
314}
315
316static int a_bidl_adis_tmout(struct ci_hdrc *ci)
317{
318 ci->fsm.a_bidl_adis_tmout = 1;
319 return 0;
320}
321
322static int b_aidl_bdis_tmout(struct ci_hdrc *ci)
323{
324 ci->fsm.a_bus_suspend = 1;
325 return 0;
326}
327
328static int b_se0_srp_tmout(struct ci_hdrc *ci)
329{
330 ci->fsm.b_se0_srp = 1;
331 return 0;
332}
333
334static int b_srp_fail_tmout(struct ci_hdrc *ci)
335{
336 ci->fsm.b_srp_done = 1;
337 return 1;
338}
339
340static int b_data_pls_tmout(struct ci_hdrc *ci)
341{
342 ci->fsm.b_srp_done = 1;
343 ci->fsm.b_bus_req = 0;
344 if (ci->fsm.power_up)
345 ci->fsm.power_up = 0;
346 hw_write_otgsc(ci, OTGSC_HABA, data: 0);
347 pm_runtime_put(dev: ci->dev);
348 return 0;
349}
350
351static int b_ssend_srp_tmout(struct ci_hdrc *ci)
352{
353 ci->fsm.b_ssend_srp = 1;
354 /* only vbus fall below B_sess_vld in b_idle state */
355 if (ci->fsm.otg->state == OTG_STATE_B_IDLE)
356 return 0;
357 else
358 return 1;
359}
360
361/*
362 * Keep this list in the same order as timers indexed
363 * by enum otg_fsm_timer in include/linux/usb/otg-fsm.h
364 */
365static int (*otg_timer_handlers[])(struct ci_hdrc *) = {
366 a_wait_vrise_tmout, /* A_WAIT_VRISE */
367 a_wait_vfall_tmout, /* A_WAIT_VFALL */
368 a_wait_bcon_tmout, /* A_WAIT_BCON */
369 a_aidl_bdis_tmout, /* A_AIDL_BDIS */
370 b_ase0_brst_tmout, /* B_ASE0_BRST */
371 a_bidl_adis_tmout, /* A_BIDL_ADIS */
372 b_aidl_bdis_tmout, /* B_AIDL_BDIS */
373 b_se0_srp_tmout, /* B_SE0_SRP */
374 b_srp_fail_tmout, /* B_SRP_FAIL */
375 NULL, /* A_WAIT_ENUM */
376 b_data_pls_tmout, /* B_DATA_PLS */
377 b_ssend_srp_tmout, /* B_SSEND_SRP */
378};
379
380/*
381 * Enable the next nearest enabled timer if have
382 */
383static enum hrtimer_restart ci_otg_hrtimer_func(struct hrtimer *t)
384{
385 struct ci_hdrc *ci = container_of(t, struct ci_hdrc, otg_fsm_hrtimer);
386 ktime_t now, *timeout;
387 unsigned long enabled_timer_bits;
388 unsigned long flags;
389 enum otg_fsm_timer cur_timer, next_timer = NUM_OTG_FSM_TIMERS;
390 int ret = -EINVAL;
391
392 spin_lock_irqsave(&ci->lock, flags);
393 enabled_timer_bits = ci->enabled_otg_timer_bits;
394 ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
395
396 now = ktime_get();
397 for_each_set_bit(cur_timer, &enabled_timer_bits, NUM_OTG_FSM_TIMERS) {
398 if (ktime_compare(cmp1: now, cmp2: ci->hr_timeouts[cur_timer]) >= 0) {
399 ci->enabled_otg_timer_bits &= ~(1 << cur_timer);
400 if (otg_timer_handlers[cur_timer])
401 ret = otg_timer_handlers[cur_timer](ci);
402 } else {
403 if ((next_timer == NUM_OTG_FSM_TIMERS) ||
404 ktime_before(cmp1: ci->hr_timeouts[cur_timer],
405 cmp2: ci->hr_timeouts[next_timer]))
406 next_timer = cur_timer;
407 }
408 }
409 /* Enable the next nearest timer */
410 if (next_timer < NUM_OTG_FSM_TIMERS) {
411 timeout = &ci->hr_timeouts[next_timer];
412 hrtimer_start_range_ns(timer: &ci->otg_fsm_hrtimer, tim: *timeout,
413 NSEC_PER_MSEC, mode: HRTIMER_MODE_ABS);
414 ci->next_otg_timer = next_timer;
415 }
416 spin_unlock_irqrestore(lock: &ci->lock, flags);
417
418 if (!ret)
419 ci_otg_queue_work(ci);
420
421 return HRTIMER_NORESTART;
422}
423
424/* Initialize timers */
425static int ci_otg_init_timers(struct ci_hdrc *ci)
426{
427 hrtimer_init(timer: &ci->otg_fsm_hrtimer, CLOCK_MONOTONIC, mode: HRTIMER_MODE_ABS);
428 ci->otg_fsm_hrtimer.function = ci_otg_hrtimer_func;
429
430 return 0;
431}
432
433/* -------------------------------------------------------------*/
434/* Operations that will be called from OTG Finite State Machine */
435/* -------------------------------------------------------------*/
436static void ci_otg_fsm_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
437{
438 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
439
440 if (t < NUM_OTG_FSM_TIMERS)
441 ci_otg_add_timer(ci, t);
442 return;
443}
444
445static void ci_otg_fsm_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer t)
446{
447 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
448
449 if (t < NUM_OTG_FSM_TIMERS)
450 ci_otg_del_timer(ci, t);
451 return;
452}
453
454/*
455 * A-device drive vbus: turn on vbus regulator and enable port power
456 * Data pulse irq should be disabled while vbus is on.
457 */
458static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
459{
460 int ret;
461 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
462
463 if (on) {
464 /* Enable power */
465 hw_write(ci, reg: OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
466 PORTSC_PP);
467 if (ci->platdata->reg_vbus) {
468 ret = regulator_enable(regulator: ci->platdata->reg_vbus);
469 if (ret) {
470 dev_err(ci->dev,
471 "Failed to enable vbus regulator, ret=%d\n",
472 ret);
473 return;
474 }
475 }
476
477 if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
478 usb_phy_vbus_on(x: ci->usb_phy);
479
480 /* Disable data pulse irq */
481 hw_write_otgsc(ci, OTGSC_DPIE, data: 0);
482
483 fsm->a_srp_det = 0;
484 fsm->power_up = 0;
485 } else {
486 if (ci->platdata->reg_vbus)
487 regulator_disable(regulator: ci->platdata->reg_vbus);
488
489 if (ci->platdata->flags & CI_HDRC_PHY_VBUS_CONTROL)
490 usb_phy_vbus_off(x: ci->usb_phy);
491
492 fsm->a_bus_drop = 1;
493 fsm->a_bus_req = 0;
494 }
495}
496
497/*
498 * Control data line by Run Stop bit.
499 */
500static void ci_otg_loc_conn(struct otg_fsm *fsm, int on)
501{
502 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
503
504 if (on)
505 hw_write(ci, reg: OP_USBCMD, USBCMD_RS, USBCMD_RS);
506 else
507 hw_write(ci, reg: OP_USBCMD, USBCMD_RS, data: 0);
508}
509
510/*
511 * Generate SOF by host.
512 * In host mode, controller will automatically send SOF.
513 * Suspend will block the data on the port.
514 *
515 * This is controlled through usbcore by usb autosuspend,
516 * so the usb device class driver need support autosuspend,
517 * otherwise the bus suspend will not happen.
518 */
519static void ci_otg_loc_sof(struct otg_fsm *fsm, int on)
520{
521 struct usb_device *udev;
522
523 if (!fsm->otg->host)
524 return;
525
526 udev = usb_hub_find_child(hdev: fsm->otg->host->root_hub, port1: 1);
527 if (!udev)
528 return;
529
530 if (on) {
531 usb_disable_autosuspend(udev);
532 } else {
533 pm_runtime_set_autosuspend_delay(dev: &udev->dev, delay: 0);
534 usb_enable_autosuspend(udev);
535 }
536}
537
538/*
539 * Start SRP pulsing by data-line pulsing,
540 * no v-bus pulsing followed
541 */
542static void ci_otg_start_pulse(struct otg_fsm *fsm)
543{
544 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
545
546 /* Hardware Assistant Data pulse */
547 hw_write_otgsc(ci, OTGSC_HADP, OTGSC_HADP);
548
549 pm_runtime_get(dev: ci->dev);
550 ci_otg_add_timer(ci, t: B_DATA_PLS);
551}
552
553static int ci_otg_start_host(struct otg_fsm *fsm, int on)
554{
555 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
556
557 if (on) {
558 ci_role_stop(ci);
559 ci_role_start(ci, role: CI_ROLE_HOST);
560 } else {
561 ci_role_stop(ci);
562 ci_role_start(ci, role: CI_ROLE_GADGET);
563 }
564 return 0;
565}
566
567static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
568{
569 struct ci_hdrc *ci = container_of(fsm, struct ci_hdrc, fsm);
570
571 if (on)
572 usb_gadget_vbus_connect(gadget: &ci->gadget);
573 else
574 usb_gadget_vbus_disconnect(gadget: &ci->gadget);
575
576 return 0;
577}
578
579static struct otg_fsm_ops ci_otg_ops = {
580 .drv_vbus = ci_otg_drv_vbus,
581 .loc_conn = ci_otg_loc_conn,
582 .loc_sof = ci_otg_loc_sof,
583 .start_pulse = ci_otg_start_pulse,
584 .add_timer = ci_otg_fsm_add_timer,
585 .del_timer = ci_otg_fsm_del_timer,
586 .start_host = ci_otg_start_host,
587 .start_gadget = ci_otg_start_gadget,
588};
589
590int ci_otg_fsm_work(struct ci_hdrc *ci)
591{
592 /*
593 * Don't do fsm transition for B device
594 * when there is no gadget class driver
595 */
596 if (ci->fsm.id && !(ci->driver) &&
597 ci->fsm.otg->state < OTG_STATE_A_IDLE)
598 return 0;
599
600 pm_runtime_get_sync(dev: ci->dev);
601 if (otg_statemachine(fsm: &ci->fsm)) {
602 if (ci->fsm.otg->state == OTG_STATE_A_IDLE) {
603 /*
604 * Further state change for cases:
605 * a_idle to b_idle; or
606 * a_idle to a_wait_vrise due to ID change(1->0), so
607 * B-dev becomes A-dev can try to start new session
608 * consequently; or
609 * a_idle to a_wait_vrise when power up
610 */
611 if ((ci->fsm.id) || (ci->id_event) ||
612 (ci->fsm.power_up)) {
613 ci_otg_queue_work(ci);
614 } else {
615 /* Enable data pulse irq */
616 hw_write(ci, reg: OP_PORTSC, PORTSC_W1C_BITS |
617 PORTSC_PP, data: 0);
618 hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
619 hw_write_otgsc(ci, OTGSC_DPIE, OTGSC_DPIE);
620 }
621 if (ci->id_event)
622 ci->id_event = false;
623 } else if (ci->fsm.otg->state == OTG_STATE_B_IDLE) {
624 if (ci->fsm.b_sess_vld) {
625 ci->fsm.power_up = 0;
626 /*
627 * Further transite to b_periphearl state
628 * when register gadget driver with vbus on
629 */
630 ci_otg_queue_work(ci);
631 }
632 } else if (ci->fsm.otg->state == OTG_STATE_A_HOST) {
633 pm_runtime_mark_last_busy(dev: ci->dev);
634 pm_runtime_put_autosuspend(dev: ci->dev);
635 return 0;
636 }
637 }
638 pm_runtime_put_sync(dev: ci->dev);
639 return 0;
640}
641
642/*
643 * Update fsm variables in each state if catching expected interrupts,
644 * called by otg fsm isr.
645 */
646static void ci_otg_fsm_event(struct ci_hdrc *ci)
647{
648 u32 intr_sts, otg_bsess_vld, port_conn;
649 struct otg_fsm *fsm = &ci->fsm;
650
651 intr_sts = hw_read_intr_status(ci);
652 otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
653 port_conn = hw_read(ci, reg: OP_PORTSC, PORTSC_CCS);
654
655 switch (ci->fsm.otg->state) {
656 case OTG_STATE_A_WAIT_BCON:
657 if (port_conn) {
658 fsm->b_conn = 1;
659 fsm->a_bus_req = 1;
660 ci_otg_queue_work(ci);
661 }
662 break;
663 case OTG_STATE_B_IDLE:
664 if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
665 fsm->b_sess_vld = 1;
666 ci_otg_queue_work(ci);
667 }
668 break;
669 case OTG_STATE_B_PERIPHERAL:
670 if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
671 ci_otg_add_timer(ci, t: B_AIDL_BDIS);
672 } else if (intr_sts & USBi_PCI) {
673 ci_otg_del_timer(ci, t: B_AIDL_BDIS);
674 if (fsm->a_bus_suspend == 1)
675 fsm->a_bus_suspend = 0;
676 }
677 break;
678 case OTG_STATE_B_HOST:
679 if ((intr_sts & USBi_PCI) && !port_conn) {
680 fsm->a_conn = 0;
681 fsm->b_bus_req = 0;
682 ci_otg_queue_work(ci);
683 }
684 break;
685 case OTG_STATE_A_PERIPHERAL:
686 if (intr_sts & USBi_SLI) {
687 fsm->b_bus_suspend = 1;
688 /*
689 * Init a timer to know how long this suspend
690 * will continue, if time out, indicates B no longer
691 * wants to be host role
692 */
693 ci_otg_add_timer(ci, t: A_BIDL_ADIS);
694 }
695
696 if (intr_sts & USBi_URI)
697 ci_otg_del_timer(ci, t: A_BIDL_ADIS);
698
699 if (intr_sts & USBi_PCI) {
700 if (fsm->b_bus_suspend == 1) {
701 ci_otg_del_timer(ci, t: A_BIDL_ADIS);
702 fsm->b_bus_suspend = 0;
703 }
704 }
705 break;
706 case OTG_STATE_A_SUSPEND:
707 if ((intr_sts & USBi_PCI) && !port_conn) {
708 fsm->b_conn = 0;
709
710 /* if gadget driver is binded */
711 if (ci->driver) {
712 /* A device to be peripheral mode */
713 ci->gadget.is_a_peripheral = 1;
714 }
715 ci_otg_queue_work(ci);
716 }
717 break;
718 case OTG_STATE_A_HOST:
719 if ((intr_sts & USBi_PCI) && !port_conn) {
720 fsm->b_conn = 0;
721 ci_otg_queue_work(ci);
722 }
723 break;
724 case OTG_STATE_B_WAIT_ACON:
725 if ((intr_sts & USBi_PCI) && port_conn) {
726 fsm->a_conn = 1;
727 ci_otg_queue_work(ci);
728 }
729 break;
730 default:
731 break;
732 }
733}
734
735/*
736 * ci_otg_irq - otg fsm related irq handling
737 * and also update otg fsm variable by monitoring usb host and udc
738 * state change interrupts.
739 * @ci: ci_hdrc
740 */
741irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
742{
743 irqreturn_t retval = IRQ_NONE;
744 u32 otgsc, otg_int_src = 0;
745 struct otg_fsm *fsm = &ci->fsm;
746
747 otgsc = hw_read_otgsc(ci, mask: ~0);
748 otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
749 fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;
750
751 if (otg_int_src) {
752 if (otg_int_src & OTGSC_DPIS) {
753 hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
754 fsm->a_srp_det = 1;
755 fsm->a_bus_drop = 0;
756 } else if (otg_int_src & OTGSC_IDIS) {
757 hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
758 if (fsm->id == 0) {
759 fsm->a_bus_drop = 0;
760 fsm->a_bus_req = 1;
761 ci->id_event = true;
762 }
763 } else if (otg_int_src & OTGSC_BSVIS) {
764 hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
765 if (otgsc & OTGSC_BSV) {
766 fsm->b_sess_vld = 1;
767 ci_otg_del_timer(ci, t: B_SSEND_SRP);
768 ci_otg_del_timer(ci, t: B_SRP_FAIL);
769 fsm->b_ssend_srp = 0;
770 } else {
771 fsm->b_sess_vld = 0;
772 if (fsm->id)
773 ci_otg_add_timer(ci, t: B_SSEND_SRP);
774 }
775 } else if (otg_int_src & OTGSC_AVVIS) {
776 hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
777 if (otgsc & OTGSC_AVV) {
778 fsm->a_vbus_vld = 1;
779 } else {
780 fsm->a_vbus_vld = 0;
781 fsm->b_conn = 0;
782 }
783 }
784 ci_otg_queue_work(ci);
785 return IRQ_HANDLED;
786 }
787
788 ci_otg_fsm_event(ci);
789
790 return retval;
791}
792
793void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
794{
795 ci_otg_queue_work(ci);
796}
797
798int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
799{
800 int retval = 0;
801
802 if (ci->phy)
803 ci->otg.phy = ci->phy;
804 else
805 ci->otg.usb_phy = ci->usb_phy;
806
807 ci->otg.gadget = &ci->gadget;
808 ci->fsm.otg = &ci->otg;
809 ci->fsm.power_up = 1;
810 ci->fsm.id = hw_read_otgsc(ci, OTGSC_ID) ? 1 : 0;
811 ci->fsm.otg->state = OTG_STATE_UNDEFINED;
812 ci->fsm.ops = &ci_otg_ops;
813 ci->gadget.hnp_polling_support = 1;
814 ci->fsm.host_req_flag = devm_kzalloc(dev: ci->dev, size: 1, GFP_KERNEL);
815 if (!ci->fsm.host_req_flag)
816 return -ENOMEM;
817
818 mutex_init(&ci->fsm.lock);
819
820 retval = ci_otg_init_timers(ci);
821 if (retval) {
822 dev_err(ci->dev, "Couldn't init OTG timers\n");
823 return retval;
824 }
825 ci->enabled_otg_timer_bits = 0;
826 ci->next_otg_timer = NUM_OTG_FSM_TIMERS;
827
828 retval = sysfs_create_group(kobj: &ci->dev->kobj, grp: &inputs_attr_group);
829 if (retval < 0) {
830 dev_dbg(ci->dev,
831 "Can't register sysfs attr group: %d\n", retval);
832 return retval;
833 }
834
835 /* Enable A vbus valid irq */
836 hw_write_otgsc(ci, OTGSC_AVVIE, OTGSC_AVVIE);
837
838 if (ci->fsm.id) {
839 ci->fsm.b_ssend_srp =
840 hw_read_otgsc(ci, OTGSC_BSV) ? 0 : 1;
841 ci->fsm.b_sess_vld =
842 hw_read_otgsc(ci, OTGSC_BSV) ? 1 : 0;
843 /* Enable BSV irq */
844 hw_write_otgsc(ci, OTGSC_BSVIE, OTGSC_BSVIE);
845 }
846
847 return 0;
848}
849
850void ci_hdrc_otg_fsm_remove(struct ci_hdrc *ci)
851{
852 sysfs_remove_group(kobj: &ci->dev->kobj, grp: &inputs_attr_group);
853}
854

source code of linux/drivers/usb/chipidea/otg_fsm.c