linux/drivers/usb/chipidea/otg.c
Li Jun 15f75defac usb: chipidea: add sys inputs for OTG fsm input
This patch adds sys input to control and show OTG fsm inputs by application,
user can do host and preipheral role switch by change these inputs.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <b47624@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 12:56:35 -07:00

147 lines
3.1 KiB
C

/*
* 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);
}