1 // SPDX-License-Identifier: GPL-2.0
3 * otg.c - ChipIdea USB IP core OTG driver
5 * Copyright (C) 2013 Freescale Semiconductor, Inc.
11 * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP
15 #include <linux/usb/otg.h>
16 #include <linux/usb/gadget.h>
17 #include <linux/usb/chipidea.h>
25 * hw_read_otgsc returns otgsc register bits value.
26 * @mask: bitfield mask
28 u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
30 struct ci_hdrc_cable *cable;
31 u32 val = hw_read(ci, OP_OTGSC, mask);
34 * If using extcon framework for VBUS and/or ID signal
35 * detection overwrite OTGSC register value
37 cable = &ci->platdata->vbus_extcon;
38 if (!IS_ERR(cable->edev)) {
55 cable = &ci->platdata->id_extcon;
56 if (!IS_ERR(cable->edev)) {
63 val &= ~OTGSC_ID; /* host */
65 val |= OTGSC_ID; /* device */
77 * hw_write_otgsc updates target bits of OTGSC register.
78 * @mask: bitfield mask
79 * @data: to be written
81 void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
83 struct ci_hdrc_cable *cable;
85 cable = &ci->platdata->vbus_extcon;
86 if (!IS_ERR(cable->edev)) {
87 if (data & mask & OTGSC_BSVIS)
88 cable->changed = false;
90 /* Don't enable vbus interrupt if using external notifier */
91 if (data & mask & OTGSC_BSVIE) {
92 cable->enabled = true;
94 } else if (mask & OTGSC_BSVIE) {
95 cable->enabled = false;
99 cable = &ci->platdata->id_extcon;
100 if (!IS_ERR(cable->edev)) {
101 if (data & mask & OTGSC_IDIS)
102 cable->changed = false;
104 /* Don't enable id interrupt if using external notifier */
105 if (data & mask & OTGSC_IDIE) {
106 cable->enabled = true;
108 } else if (mask & OTGSC_IDIE) {
109 cable->enabled = false;
113 hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
117 * ci_otg_role - pick role based on ID pin state
118 * @ci: the controller
120 enum ci_role ci_otg_role(struct ci_hdrc *ci)
122 enum ci_role role = hw_read_otgsc(ci, OTGSC_ID)
129 void ci_handle_vbus_change(struct ci_hdrc *ci)
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);
141 * When we switch to device mode, the vbus value should be lower
142 * than OTGSC_BSV before connecting to host.
144 * @ci: the controller
146 * This function returns an error code if timeout
148 static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
150 unsigned long elapse = jiffies + msecs_to_jiffies(5000);
151 u32 mask = OTGSC_BSV;
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",
165 static void ci_handle_id_switch(struct ci_hdrc *ci)
169 mutex_lock(&ci->mutex);
170 role = ci_otg_role(ci);
171 if (role != ci->role) {
172 dev_dbg(ci->dev, "switching from %s to %s\n",
173 ci_role(ci)->name, ci->roles[role]->name);
177 if (role == CI_ROLE_GADGET &&
178 IS_ERR(ci->platdata->vbus_extcon.edev))
180 * Wait vbus lower than OTGSC_BSV before connecting
181 * to host. If connecting status is from an external
182 * connector instead of register, we don't need to
183 * care vbus on the board, since it will not affect
184 * external connector status.
186 hw_wait_vbus_lower_bsv(ci);
188 ci_role_start(ci, role);
189 /* vbus change may have already occurred */
190 if (role == CI_ROLE_GADGET)
191 ci_handle_vbus_change(ci);
193 mutex_unlock(&ci->mutex);
196 * ci_otg_work - perform otg (vbus/id) event handle
199 static void ci_otg_work(struct work_struct *work)
201 struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work);
203 if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) {
208 pm_runtime_get_sync(ci->dev);
211 ci->id_event = false;
212 ci_handle_id_switch(ci);
215 if (ci->b_sess_valid_event) {
216 ci->b_sess_valid_event = false;
217 ci_handle_vbus_change(ci);
220 pm_runtime_put_sync(ci->dev);
227 * ci_hdrc_otg_init - initialize otg struct
230 int ci_hdrc_otg_init(struct ci_hdrc *ci)
232 INIT_WORK(&ci->work, ci_otg_work);
233 ci->wq = create_freezable_workqueue("ci_otg");
235 dev_err(ci->dev, "can't create workqueue\n");
239 if (ci_otg_is_fsm_mode(ci))
240 return ci_hdrc_otg_fsm_init(ci);
246 * ci_hdrc_otg_destroy - destroy otg struct
249 void ci_hdrc_otg_destroy(struct ci_hdrc *ci)
252 flush_workqueue(ci->wq);
253 destroy_workqueue(ci->wq);
255 /* Disable all OTG irq and clear status */
256 hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS,
257 OTGSC_INT_STATUS_BITS);
258 if (ci_otg_is_fsm_mode(ci))
259 ci_hdrc_otg_fsm_remove(ci);