2 * otg.c - ChipIdea USB IP core OTG driver
4 * Copyright (C) 2013 Freescale Semiconductor, Inc.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP
18 #include <linux/usb/otg.h>
19 #include <linux/usb/gadget.h>
20 #include <linux/usb/chipidea.h>
28 * hw_read_otgsc returns otgsc register bits value.
29 * @mask: bitfield mask
31 u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
33 struct ci_hdrc_cable *cable;
34 u32 val = hw_read(ci, OP_OTGSC, mask);
37 * If using extcon framework for VBUS and/or ID signal
38 * detection overwrite OTGSC register value
40 cable = &ci->platdata->vbus_extcon;
41 if (!IS_ERR(cable->edev)) {
58 cable = &ci->platdata->id_extcon;
59 if (!IS_ERR(cable->edev)) {
80 * hw_write_otgsc updates target bits of OTGSC register.
81 * @mask: bitfield mask
82 * @data: to be written
84 void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
86 struct ci_hdrc_cable *cable;
88 cable = &ci->platdata->vbus_extcon;
89 if (!IS_ERR(cable->edev)) {
90 if (data & mask & OTGSC_BSVIS)
91 cable->changed = false;
93 /* Don't enable vbus interrupt if using external notifier */
94 if (data & mask & OTGSC_BSVIE) {
95 cable->enabled = true;
97 } else if (mask & OTGSC_BSVIE) {
98 cable->enabled = false;
102 cable = &ci->platdata->id_extcon;
103 if (!IS_ERR(cable->edev)) {
104 if (data & mask & OTGSC_IDIS)
105 cable->changed = false;
107 /* Don't enable id interrupt if using external notifier */
108 if (data & mask & OTGSC_IDIE) {
109 cable->enabled = true;
111 } else if (mask & OTGSC_IDIE) {
112 cable->enabled = false;
116 hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
120 * ci_otg_role - pick role based on ID pin state
121 * @ci: the controller
123 enum ci_role ci_otg_role(struct ci_hdrc *ci)
125 enum ci_role role = hw_read_otgsc(ci, OTGSC_ID)
132 void ci_handle_vbus_change(struct ci_hdrc *ci)
137 if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active)
138 usb_gadget_vbus_connect(&ci->gadget);
139 else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active)
140 usb_gadget_vbus_disconnect(&ci->gadget);
144 * When we switch to device mode, the vbus value should be lower
145 * than OTGSC_BSV before connecting to host.
147 * @ci: the controller
149 * This function returns an error code if timeout
151 static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci)
153 unsigned long elapse = jiffies + msecs_to_jiffies(5000);
154 u32 mask = OTGSC_BSV;
156 while (hw_read_otgsc(ci, mask)) {
157 if (time_after(jiffies, elapse)) {
158 dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n",
168 static void ci_handle_id_switch(struct ci_hdrc *ci)
170 enum ci_role role = ci_otg_role(ci);
172 if (role != ci->role) {
173 dev_dbg(ci->dev, "switching from %s to %s\n",
174 ci_role(ci)->name, ci->roles[role]->name);
178 if (role == CI_ROLE_GADGET &&
179 IS_ERR(ci->platdata->vbus_extcon.edev))
181 * Wait vbus lower than OTGSC_BSV before connecting
182 * to host. If connecting status is from an external
183 * connector instead of register, we don't need to
184 * care vbus on the board, since it will not affect
185 * external connector status.
187 hw_wait_vbus_lower_bsv(ci);
189 ci_role_start(ci, role);
190 /* vbus change may have already occurred */
191 if (role == CI_ROLE_GADGET)
192 ci_handle_vbus_change(ci);
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);