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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * otg.c - ChipIdea USB IP core OTG driver
4 *
5 * Copyright (C) 2013 Freescale Semiconductor, Inc.
6 *
7 * Author: Peter Chen
8 */
9
10/*
11 * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP
12 * are also included.
13 */
14
15#include <linux/usb/otg.h>
16#include <linux/usb/gadget.h>
17#include <linux/usb/chipidea.h>
18
19#include "ci.h"
20#include "bits.h"
21#include "otg.h"
22#include "otg_fsm.h"
23
24/**
25 * hw_read_otgsc - returns otgsc register bits value.
26 * @ci: the controller
27 * @mask: bitfield mask
28 */
29u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
30{
31 struct ci_hdrc_cable *cable;
32 u32 val = hw_read(ci, OP_OTGSC, mask);
33
34 /*
35 * If using extcon framework for VBUS and/or ID signal
36 * detection overwrite OTGSC register value
37 */
38 cable = &ci->platdata->vbus_extcon;
39 if (!IS_ERR(cable->edev) || ci->role_switch) {
40 if (cable->changed)
41 val |= OTGSC_BSVIS;
42 else
43 val &= ~OTGSC_BSVIS;
44
45 if (cable->connected)
46 val |= OTGSC_BSV;
47 else
48 val &= ~OTGSC_BSV;
49
50 if (cable->enabled)
51 val |= OTGSC_BSVIE;
52 else
53 val &= ~OTGSC_BSVIE;
54 }
55
56 cable = &ci->platdata->id_extcon;
57 if (!IS_ERR(cable->edev) || ci->role_switch) {
58 if (cable->changed)
59 val |= OTGSC_IDIS;
60 else
61 val &= ~OTGSC_IDIS;
62
63 if (cable->connected)
64 val &= ~OTGSC_ID; /* host */
65 else
66 val |= OTGSC_ID; /* device */
67
68 if (cable->enabled)
69 val |= OTGSC_IDIE;
70 else
71 val &= ~OTGSC_IDIE;
72 }
73
74 return val & mask;
75}
76
77/**
78 * hw_write_otgsc - updates target bits of OTGSC register.
79 * @ci: the controller
80 * @mask: bitfield mask
81 * @data: to be written
82 */
83void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
84{
85 struct ci_hdrc_cable *cable;
86
87 cable = &ci->platdata->vbus_extcon;
88 if (!IS_ERR(cable->edev) || ci->role_switch) {
89 if (data & mask & OTGSC_BSVIS)
90 cable->changed = false;
91
92 /* Don't enable vbus interrupt if using external notifier */
93 if (data & mask & OTGSC_BSVIE) {
94 cable->enabled = true;
95 data &= ~OTGSC_BSVIE;
96 } else if (mask & OTGSC_BSVIE) {
97 cable->enabled = false;
98 }
99 }
100
101 cable = &ci->platdata->id_extcon;
102 if (!IS_ERR(cable->edev) || ci->role_switch) {
103 if (data & mask & OTGSC_IDIS)
104 cable->changed = false;
105
106 /* Don't enable id interrupt if using external notifier */
107 if (data & mask & OTGSC_IDIE) {
108 cable->enabled = true;
109 data &= ~OTGSC_IDIE;
110 } else if (mask & OTGSC_IDIE) {
111 cable->enabled = false;
112 }
113 }
114
115 hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
116}
117
118/**
119 * ci_otg_role - pick role based on ID pin state
120 * @ci: the controller
121 */
122enum ci_role ci_otg_role(struct ci_hdrc *ci)
123{
124 enum ci_role role = hw_read_otgsc(ci, OTGSC_ID)
125 ? CI_ROLE_GADGET
126 : CI_ROLE_HOST;
127
128 return role;
129}
130
131void ci_handle_vbus_change(struct ci_hdrc *ci)
132{
133 if (!ci->is_otg) {
134 if (ci->platdata->flags & CI_HDRC_FORCE_VBUS_ACTIVE_ALWAYS)
135 usb_gadget_vbus_connect(&ci->gadget);
136 return;
137 }
138
139 if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active)
140 usb_gadget_vbus_connect(&ci->gadget);
141 else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active)
142 usb_gadget_vbus_disconnect(&ci->gadget);
143}
144
145/**
146 * hw_wait_vbus_lower_bsv - When we switch to device mode, the vbus value
147 * should be lower than OTGSC_BSV before connecting
148 * to host.
149 *
150 * @ci: the controller
151 *
152 * This function returns an error code if timeout
153 */
154static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
155{
156 unsigned long elapse = jiffies + msecs_to_jiffies(5000);
157 u32 mask = OTGSC_BSV;
158
159 while (hw_read_otgsc(ci, mask)) {
160 if (time_after(jiffies, elapse)) {
161 dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n",
162 mask);
163 return -ETIMEDOUT;
164 }
165 msleep(20);
166 }
167
168 return 0;
169}
170
171void ci_handle_id_switch(struct ci_hdrc *ci)
172{
173 enum ci_role role;
174
175 mutex_lock(&ci->mutex);
176 role = ci_otg_role(ci);
177 if (role != ci->role) {
178 dev_dbg(ci->dev, "switching from %s to %s\n",
179 ci_role(ci)->name, ci->roles[role]->name);
180
181 if (ci->vbus_active && ci->role == CI_ROLE_GADGET)
182 /*
183 * vbus disconnect event is lost due to role
184 * switch occurs during system suspend.
185 */
186 usb_gadget_vbus_disconnect(&ci->gadget);
187
188 ci_role_stop(ci);
189
190 if (role == CI_ROLE_GADGET &&
191 IS_ERR(ci->platdata->vbus_extcon.edev))
192 /*
193 * Wait vbus lower than OTGSC_BSV before connecting
194 * to host. If connecting status is from an external
195 * connector instead of register, we don't need to
196 * care vbus on the board, since it will not affect
197 * external connector status.
198 */
199 hw_wait_vbus_lower_bsv(ci);
200
201 ci_role_start(ci, role);
202 /* vbus change may have already occurred */
203 if (role == CI_ROLE_GADGET)
204 ci_handle_vbus_change(ci);
205 }
206 mutex_unlock(&ci->mutex);
207}
208/**
209 * ci_otg_work - perform otg (vbus/id) event handle
210 * @work: work struct
211 */
212static void ci_otg_work(struct work_struct *work)
213{
214 struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work);
215
216 if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) {
217 enable_irq(ci->irq);
218 return;
219 }
220
221 pm_runtime_get_sync(ci->dev);
222
223 if (ci->id_event) {
224 ci->id_event = false;
225 ci_handle_id_switch(ci);
226 }
227
228 if (ci->b_sess_valid_event) {
229 ci->b_sess_valid_event = false;
230 ci_handle_vbus_change(ci);
231 }
232
233 pm_runtime_put_sync(ci->dev);
234
235 enable_irq(ci->irq);
236}
237
238
239/**
240 * ci_hdrc_otg_init - initialize otg struct
241 * @ci: the controller
242 */
243int ci_hdrc_otg_init(struct ci_hdrc *ci)
244{
245 INIT_WORK(&ci->work, ci_otg_work);
246 ci->wq = create_freezable_workqueue("ci_otg");
247 if (!ci->wq) {
248 dev_err(ci->dev, "can't create workqueue\n");
249 return -ENODEV;
250 }
251
252 if (ci_otg_is_fsm_mode(ci))
253 return ci_hdrc_otg_fsm_init(ci);
254
255 return 0;
256}
257
258/**
259 * ci_hdrc_otg_destroy - destroy otg struct
260 * @ci: the controller
261 */
262void ci_hdrc_otg_destroy(struct ci_hdrc *ci)
263{
264 if (ci->wq)
265 destroy_workqueue(ci->wq);
266
267 /* Disable all OTG irq and clear status */
268 hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS,
269 OTGSC_INT_STATUS_BITS);
270 if (ci_otg_is_fsm_mode(ci))
271 ci_hdrc_otg_fsm_remove(ci);
272}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * otg.c - ChipIdea USB IP core OTG driver
4 *
5 * Copyright (C) 2013 Freescale Semiconductor, Inc.
6 *
7 * Author: Peter Chen
8 */
9
10/*
11 * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP
12 * are also included.
13 */
14
15#include <linux/usb/otg.h>
16#include <linux/usb/gadget.h>
17#include <linux/usb/chipidea.h>
18
19#include "ci.h"
20#include "bits.h"
21#include "otg.h"
22#include "otg_fsm.h"
23
24/**
25 * hw_read_otgsc returns otgsc register bits value.
26 * @mask: bitfield mask
27 */
28u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
29{
30 struct ci_hdrc_cable *cable;
31 u32 val = hw_read(ci, OP_OTGSC, mask);
32
33 /*
34 * If using extcon framework for VBUS and/or ID signal
35 * detection overwrite OTGSC register value
36 */
37 cable = &ci->platdata->vbus_extcon;
38 if (!IS_ERR(cable->edev)) {
39 if (cable->changed)
40 val |= OTGSC_BSVIS;
41 else
42 val &= ~OTGSC_BSVIS;
43
44 if (cable->connected)
45 val |= OTGSC_BSV;
46 else
47 val &= ~OTGSC_BSV;
48
49 if (cable->enabled)
50 val |= OTGSC_BSVIE;
51 else
52 val &= ~OTGSC_BSVIE;
53 }
54
55 cable = &ci->platdata->id_extcon;
56 if (!IS_ERR(cable->edev)) {
57 if (cable->changed)
58 val |= OTGSC_IDIS;
59 else
60 val &= ~OTGSC_IDIS;
61
62 if (cable->connected)
63 val &= ~OTGSC_ID; /* host */
64 else
65 val |= OTGSC_ID; /* device */
66
67 if (cable->enabled)
68 val |= OTGSC_IDIE;
69 else
70 val &= ~OTGSC_IDIE;
71 }
72
73 return val & mask;
74}
75
76/**
77 * hw_write_otgsc updates target bits of OTGSC register.
78 * @mask: bitfield mask
79 * @data: to be written
80 */
81void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
82{
83 struct ci_hdrc_cable *cable;
84
85 cable = &ci->platdata->vbus_extcon;
86 if (!IS_ERR(cable->edev)) {
87 if (data & mask & OTGSC_BSVIS)
88 cable->changed = false;
89
90 /* Don't enable vbus interrupt if using external notifier */
91 if (data & mask & OTGSC_BSVIE) {
92 cable->enabled = true;
93 data &= ~OTGSC_BSVIE;
94 } else if (mask & OTGSC_BSVIE) {
95 cable->enabled = false;
96 }
97 }
98
99 cable = &ci->platdata->id_extcon;
100 if (!IS_ERR(cable->edev)) {
101 if (data & mask & OTGSC_IDIS)
102 cable->changed = false;
103
104 /* Don't enable id interrupt if using external notifier */
105 if (data & mask & OTGSC_IDIE) {
106 cable->enabled = true;
107 data &= ~OTGSC_IDIE;
108 } else if (mask & OTGSC_IDIE) {
109 cable->enabled = false;
110 }
111 }
112
113 hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
114}
115
116/**
117 * ci_otg_role - pick role based on ID pin state
118 * @ci: the controller
119 */
120enum ci_role ci_otg_role(struct ci_hdrc *ci)
121{
122 enum ci_role role = hw_read_otgsc(ci, OTGSC_ID)
123 ? CI_ROLE_GADGET
124 : CI_ROLE_HOST;
125
126 return role;
127}
128
129void ci_handle_vbus_change(struct ci_hdrc *ci)
130{
131 if (!ci->is_otg)
132 return;
133
134 if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active)
135 usb_gadget_vbus_connect(&ci->gadget);
136 else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active)
137 usb_gadget_vbus_disconnect(&ci->gadget);
138}
139
140/**
141 * When we switch to device mode, the vbus value should be lower
142 * than OTGSC_BSV before connecting to host.
143 *
144 * @ci: the controller
145 *
146 * This function returns an error code if timeout
147 */
148static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
149{
150 unsigned long elapse = jiffies + msecs_to_jiffies(5000);
151 u32 mask = OTGSC_BSV;
152
153 while (hw_read_otgsc(ci, mask)) {
154 if (time_after(jiffies, elapse)) {
155 dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n",
156 mask);
157 return -ETIMEDOUT;
158 }
159 msleep(20);
160 }
161
162 return 0;
163}
164
165static void ci_handle_id_switch(struct ci_hdrc *ci)
166{
167 enum ci_role role = ci_otg_role(ci);
168
169 if (role != ci->role) {
170 dev_dbg(ci->dev, "switching from %s to %s\n",
171 ci_role(ci)->name, ci->roles[role]->name);
172
173 ci_role_stop(ci);
174
175 if (role == CI_ROLE_GADGET &&
176 IS_ERR(ci->platdata->vbus_extcon.edev))
177 /*
178 * Wait vbus lower than OTGSC_BSV before connecting
179 * to host. If connecting status is from an external
180 * connector instead of register, we don't need to
181 * care vbus on the board, since it will not affect
182 * external connector status.
183 */
184 hw_wait_vbus_lower_bsv(ci);
185
186 ci_role_start(ci, role);
187 /* vbus change may have already occurred */
188 if (role == CI_ROLE_GADGET)
189 ci_handle_vbus_change(ci);
190 }
191}
192/**
193 * ci_otg_work - perform otg (vbus/id) event handle
194 * @work: work struct
195 */
196static void ci_otg_work(struct work_struct *work)
197{
198 struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work);
199
200 if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) {
201 enable_irq(ci->irq);
202 return;
203 }
204
205 pm_runtime_get_sync(ci->dev);
206 if (ci->id_event) {
207 ci->id_event = false;
208 ci_handle_id_switch(ci);
209 } else if (ci->b_sess_valid_event) {
210 ci->b_sess_valid_event = false;
211 ci_handle_vbus_change(ci);
212 } else
213 dev_err(ci->dev, "unexpected event occurs at %s\n", __func__);
214 pm_runtime_put_sync(ci->dev);
215
216 enable_irq(ci->irq);
217}
218
219
220/**
221 * ci_hdrc_otg_init - initialize otg struct
222 * ci: the controller
223 */
224int ci_hdrc_otg_init(struct ci_hdrc *ci)
225{
226 INIT_WORK(&ci->work, ci_otg_work);
227 ci->wq = create_freezable_workqueue("ci_otg");
228 if (!ci->wq) {
229 dev_err(ci->dev, "can't create workqueue\n");
230 return -ENODEV;
231 }
232
233 if (ci_otg_is_fsm_mode(ci))
234 return ci_hdrc_otg_fsm_init(ci);
235
236 return 0;
237}
238
239/**
240 * ci_hdrc_otg_destroy - destroy otg struct
241 * ci: the controller
242 */
243void ci_hdrc_otg_destroy(struct ci_hdrc *ci)
244{
245 if (ci->wq) {
246 flush_workqueue(ci->wq);
247 destroy_workqueue(ci->wq);
248 }
249 /* Disable all OTG irq and clear status */
250 hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS,
251 OTGSC_INT_STATUS_BITS);
252 if (ci_otg_is_fsm_mode(ci))
253 ci_hdrc_otg_fsm_remove(ci);
254}