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, it may include OTG operation
18 #include <linux/usb/otg.h>
19 #include <linux/usb/gadget.h>
20 #include <linux/usb/chipidea.h>
27 * ci_otg_role - pick role based on ID pin state
30 enum ci_role ci_otg_role(struct ci_hdrc *ci)
32 u32 sts = hw_read(ci, OP_OTGSC, ~0);
33 enum ci_role role = sts & OTGSC_ID
40 void ci_handle_vbus_change(struct ci_hdrc *ci)
47 otgsc = hw_read(ci, OP_OTGSC, ~0);
49 if (otgsc & OTGSC_BSV)
50 usb_gadget_vbus_connect(&ci->gadget);
52 usb_gadget_vbus_disconnect(&ci->gadget);
55 #define CI_VBUS_STABLE_TIMEOUT_MS 5000
56 static void ci_handle_id_switch(struct ci_hdrc *ci)
58 enum ci_role role = ci_otg_role(ci);
60 if (role != ci->role) {
61 dev_dbg(ci->dev, "switching from %s to %s\n",
62 ci_role(ci)->name, ci->roles[role]->name);
65 /* wait vbus lower than OTGSC_BSV */
66 hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0,
67 CI_VBUS_STABLE_TIMEOUT_MS);
68 ci_role_start(ci, role);
72 * ci_otg_work - perform otg (vbus/id) event handle
75 static void ci_otg_work(struct work_struct *work)
77 struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work);
81 ci_handle_id_switch(ci);
82 } else if (ci->b_sess_valid_event) {
83 ci->b_sess_valid_event = false;
84 ci_handle_vbus_change(ci);
86 dev_err(ci->dev, "unexpected event occurs at %s\n", __func__);
93 * ci_hdrc_otg_init - initialize otg struct
96 int ci_hdrc_otg_init(struct ci_hdrc *ci)
98 INIT_WORK(&ci->work, ci_otg_work);
99 ci->wq = create_singlethread_workqueue("ci_otg");
101 dev_err(ci->dev, "can't create workqueue\n");
109 * ci_hdrc_otg_destroy - destroy otg struct
112 void ci_hdrc_otg_destroy(struct ci_hdrc *ci)
115 flush_workqueue(ci->wq);
116 destroy_workqueue(ci->wq);
118 ci_disable_otg_interrupt(ci, OTGSC_INT_EN_BITS);
119 ci_clear_otg_interrupt(ci, OTGSC_INT_STATUS_BITS);