otg.rar_otg_usb otg

/* * otg.c - ChipIdea USB IP core OTG driver * * Copyright (C) 2013 Freescale Semiconductor, Inc. * * Author: Peter Chen * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ /* * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP * are also included. */ #include <linux/usb/otg.h> #include <linux/usb/gadget.h> #include <linux/usb/chipidea.h> #include "ci.h" #include "bits.h" #include "otg.h" #include "otg_fsm.h" /** * hw_read_otgsc returns otgsc register bits value. * @mask: bitfield mask */ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask) { return hw_read(ci, OP_OTGSC, mask); } /** * hw_write_otgsc updates target bits of OTGSC register. * @mask: bitfield mask * @data: to be written */ void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data) { hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data); } /** * ci_otg_role - pick role based on ID pin state * @ci: the controller */ enum ci_role ci_otg_role(struct ci_hdrc *ci) { enum ci_role role = hw_read_otgsc(ci, OTGSC_ID) ? CI_ROLE_GADGET : CI_ROLE_HOST; return role; } void ci_handle_vbus_change(struct ci_hdrc *ci) { if (!ci->is_otg) return; if (hw_read_otgsc(ci, OTGSC_BSV)) usb_gadget_vbus_connect(&ci->gadget); else usb_gadget_vbus_disconnect(&ci->gadget); } #define CI_VBUS_STABLE_TIMEOUT_MS 5000 static void ci_handle_id_switch(struct ci_hdrc *ci) { enum ci_role role = ci_otg_role(ci); if (role != ci->role) { dev_dbg(ci->dev, "switching from %s to %s\n", ci_role(ci)->name, ci->roles[role]->name); ci_role_stop(ci); /* wait vbus lower than OTGSC_BSV */ hw_wait_reg(ci, OP_OTGSC, OTGSC_BSV, 0, CI_VBUS_STABLE_TIMEOUT_MS); ci_role_start(ci, role); } } /** * ci_otg_work - perform otg (vbus/id) event handle * @work: work struct */ static void ci_otg_work(struct work_struct *work) { struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work); if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) { enable_irq(ci->irq); return; } if (ci->id_event) { ci->id_event = false; ci_handle_id_switch(ci); } else if (ci->b_sess_valid_event) { ci->b_sess_valid_event = false; ci_handle_vbus_change(ci); } else dev_err(ci->dev, "unexpected event occurs at %s\n", __func__); enable_irq(ci->irq); } /** * ci_hdrc_otg_init - initialize otg struct * ci: the controller */ int ci_hdrc_otg_init(struct ci_hdrc *ci) { INIT_WORK(&ci->work, ci_otg_work); ci->wq = create_singlethread_workqueue("ci_otg"); if (!ci->wq) { dev_err(ci->dev, "can't create workqueue\n"); return -ENODEV; } if (ci_otg_is_fsm_mode(ci)) return ci_hdrc_otg_fsm_init(ci); return 0; } /** * ci_hdrc_otg_destroy - destroy otg struct * ci: the controller */ void ci_hdrc_otg_destroy(struct ci_hdrc *ci) { if (ci->wq) { flush_workqueue(ci->wq); destroy_workqueue(ci->wq); } /* Disable all OTG irq and clear status */ hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS, OTGSC_INT_STATUS_BITS); if (ci_otg_is_fsm_mode(ci)) ci_hdrc_otg_fsm_remove(ci); }