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linux-zen-desktop/drivers/usb/common/usb-otg-fsm.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* OTG Finite State Machine from OTG spec
*
* Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
*
* Author: Li Yang <LeoLi@freescale.com>
* Jerry Huang <Chang-Ming.Huang@freescale.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/usb.h>
#include <linux/usb/gadget.h>
#include <linux/usb/otg.h>
#include <linux/usb/otg-fsm.h>
#ifdef VERBOSE
#define VDBG(fmt, args...) pr_debug("[%s] " fmt, \
__func__, ## args)
#else
#define VDBG(stuff...) do {} while (0)
#endif
/* Change USB protocol when there is a protocol change */
static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
{
int ret = 0;
if (fsm->protocol != protocol) {
VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
fsm->protocol, protocol);
/* stop old protocol */
if (fsm->protocol == PROTO_HOST)
ret = otg_start_host(fsm, 0);
else if (fsm->protocol == PROTO_GADGET)
ret = otg_start_gadget(fsm, 0);
if (ret)
return ret;
/* start new protocol */
if (protocol == PROTO_HOST)
ret = otg_start_host(fsm, 1);
else if (protocol == PROTO_GADGET)
ret = otg_start_gadget(fsm, 1);
if (ret)
return ret;
fsm->protocol = protocol;
return 0;
}
return 0;
}
/* Called when leaving a state. Do state clean up jobs here */
static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
{
switch (old_state) {
case OTG_STATE_B_IDLE:
otg_del_timer(fsm, B_SE0_SRP);
fsm->b_se0_srp = 0;
fsm->adp_sns = 0;
fsm->adp_prb = 0;
break;
case OTG_STATE_B_SRP_INIT:
fsm->data_pulse = 0;
fsm->b_srp_done = 0;
break;
case OTG_STATE_B_PERIPHERAL:
if (fsm->otg->gadget)
fsm->otg->gadget->host_request_flag = 0;
break;
case OTG_STATE_B_WAIT_ACON:
otg_del_timer(fsm, B_ASE0_BRST);
fsm->b_ase0_brst_tmout = 0;
break;
case OTG_STATE_B_HOST:
break;
case OTG_STATE_A_IDLE:
fsm->adp_prb = 0;
break;
case OTG_STATE_A_WAIT_VRISE:
otg_del_timer(fsm, A_WAIT_VRISE);
fsm->a_wait_vrise_tmout = 0;
break;
case OTG_STATE_A_WAIT_BCON:
otg_del_timer(fsm, A_WAIT_BCON);
fsm->a_wait_bcon_tmout = 0;
break;
case OTG_STATE_A_HOST:
otg_del_timer(fsm, A_WAIT_ENUM);
break;
case OTG_STATE_A_SUSPEND:
otg_del_timer(fsm, A_AIDL_BDIS);
fsm->a_aidl_bdis_tmout = 0;
fsm->a_suspend_req_inf = 0;
break;
case OTG_STATE_A_PERIPHERAL:
otg_del_timer(fsm, A_BIDL_ADIS);
fsm->a_bidl_adis_tmout = 0;
if (fsm->otg->gadget)
fsm->otg->gadget->host_request_flag = 0;
break;
case OTG_STATE_A_WAIT_VFALL:
otg_del_timer(fsm, A_WAIT_VFALL);
fsm->a_wait_vfall_tmout = 0;
otg_del_timer(fsm, A_WAIT_VRISE);
break;
case OTG_STATE_A_VBUS_ERR:
break;
default:
break;
}
}
static void otg_hnp_polling_work(struct work_struct *work)
{
struct otg_fsm *fsm = container_of(to_delayed_work(work),
struct otg_fsm, hnp_polling_work);
struct usb_device *udev;
enum usb_otg_state state = fsm->otg->state;
u8 flag;
int retval;
if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
return;
udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
if (!udev) {
dev_err(fsm->otg->host->controller,
"no usb dev connected, can't start HNP polling\n");
return;
}
*fsm->host_req_flag = 0;
/* Get host request flag from connected USB device */
retval = usb_control_msg(udev,
usb_rcvctrlpipe(udev, 0),
USB_REQ_GET_STATUS,
USB_DIR_IN | USB_RECIP_DEVICE,
0,
OTG_STS_SELECTOR,
fsm->host_req_flag,
1,
USB_CTRL_GET_TIMEOUT);
if (retval != 1) {
dev_err(&udev->dev, "Get one byte OTG status failed\n");
return;
}
flag = *fsm->host_req_flag;
if (flag == 0) {
/* Continue HNP polling */
schedule_delayed_work(&fsm->hnp_polling_work,
msecs_to_jiffies(T_HOST_REQ_POLL));
return;
} else if (flag != HOST_REQUEST_FLAG) {
dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
return;
}
/* Host request flag is set */
if (state == OTG_STATE_A_HOST) {
/* Set b_hnp_enable */
if (!fsm->otg->host->b_hnp_enable) {
retval = usb_control_msg(udev,
usb_sndctrlpipe(udev, 0),
USB_REQ_SET_FEATURE, 0,
USB_DEVICE_B_HNP_ENABLE,
0, NULL, 0,
USB_CTRL_SET_TIMEOUT);
if (retval >= 0)
fsm->otg->host->b_hnp_enable = 1;
}
fsm->a_bus_req = 0;
} else if (state == OTG_STATE_B_HOST) {
fsm->b_bus_req = 0;
}
otg_statemachine(fsm);
}
static void otg_start_hnp_polling(struct otg_fsm *fsm)
{
/*
* The memory of host_req_flag should be allocated by
* controller driver, otherwise, hnp polling is not started.
*/
if (!fsm->host_req_flag)
return;
if (!fsm->hnp_work_inited) {
INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
fsm->hnp_work_inited = true;
}
schedule_delayed_work(&fsm->hnp_polling_work,
msecs_to_jiffies(T_HOST_REQ_POLL));
}
/* Called when entering a state */
static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
{
if (fsm->otg->state == new_state)
return 0;
VDBG("Set state: %s\n", usb_otg_state_string(new_state));
otg_leave_state(fsm, fsm->otg->state);
switch (new_state) {
case OTG_STATE_B_IDLE:
otg_drv_vbus(fsm, 0);
otg_chrg_vbus(fsm, 0);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
/*
* Driver is responsible for starting ADP probing
* if ADP sensing times out.
*/
otg_start_adp_sns(fsm);
otg_set_protocol(fsm, PROTO_UNDEF);
otg_add_timer(fsm, B_SE0_SRP);
break;
case OTG_STATE_B_SRP_INIT:
otg_start_pulse(fsm);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_UNDEF);
otg_add_timer(fsm, B_SRP_FAIL);
break;
case OTG_STATE_B_PERIPHERAL:
otg_chrg_vbus(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_GADGET);
otg_loc_conn(fsm, 1);
break;
case OTG_STATE_B_WAIT_ACON:
otg_chrg_vbus(fsm, 0);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_HOST);
otg_add_timer(fsm, B_ASE0_BRST);
fsm->a_bus_suspend = 0;
break;
case OTG_STATE_B_HOST:
otg_chrg_vbus(fsm, 0);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 1);
otg_set_protocol(fsm, PROTO_HOST);
usb_bus_start_enum(fsm->otg->host,
fsm->otg->host->otg_port);
otg_start_hnp_polling(fsm);
break;
case OTG_STATE_A_IDLE:
otg_drv_vbus(fsm, 0);
otg_chrg_vbus(fsm, 0);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_start_adp_prb(fsm);
otg_set_protocol(fsm, PROTO_HOST);
break;
case OTG_STATE_A_WAIT_VRISE:
otg_drv_vbus(fsm, 1);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_HOST);
otg_add_timer(fsm, A_WAIT_VRISE);
break;
case OTG_STATE_A_WAIT_BCON:
otg_drv_vbus(fsm, 1);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_HOST);
otg_add_timer(fsm, A_WAIT_BCON);
break;
case OTG_STATE_A_HOST:
otg_drv_vbus(fsm, 1);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 1);
otg_set_protocol(fsm, PROTO_HOST);
/*
* When HNP is triggered while a_bus_req = 0, a_host will
* suspend too fast to complete a_set_b_hnp_en
*/
if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
otg_add_timer(fsm, A_WAIT_ENUM);
otg_start_hnp_polling(fsm);
break;
case OTG_STATE_A_SUSPEND:
otg_drv_vbus(fsm, 1);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_HOST);
otg_add_timer(fsm, A_AIDL_BDIS);
break;
case OTG_STATE_A_PERIPHERAL:
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_GADGET);
otg_drv_vbus(fsm, 1);
otg_loc_conn(fsm, 1);
otg_add_timer(fsm, A_BIDL_ADIS);
break;
case OTG_STATE_A_WAIT_VFALL:
otg_drv_vbus(fsm, 0);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_HOST);
otg_add_timer(fsm, A_WAIT_VFALL);
break;
case OTG_STATE_A_VBUS_ERR:
otg_drv_vbus(fsm, 0);
otg_loc_conn(fsm, 0);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_UNDEF);
break;
default:
break;
}
fsm->otg->state = new_state;
fsm->state_changed = 1;
return 0;
}
/* State change judgement */
int otg_statemachine(struct otg_fsm *fsm)
{
enum usb_otg_state state;
mutex_lock(&fsm->lock);
state = fsm->otg->state;
fsm->state_changed = 0;
/* State machine state change judgement */
switch (state) {
case OTG_STATE_UNDEFINED:
VDBG("fsm->id = %d\n", fsm->id);
if (fsm->id)
otg_set_state(fsm, OTG_STATE_B_IDLE);
else
otg_set_state(fsm, OTG_STATE_A_IDLE);
break;
case OTG_STATE_B_IDLE:
if (!fsm->id)
otg_set_state(fsm, OTG_STATE_A_IDLE);
else if (fsm->b_sess_vld && fsm->otg->gadget)
otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
fsm->b_ssend_srp && fsm->b_se0_srp)
otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
break;
case OTG_STATE_B_SRP_INIT:
if (!fsm->id || fsm->b_srp_done)
otg_set_state(fsm, OTG_STATE_B_IDLE);
break;
case OTG_STATE_B_PERIPHERAL:
if (!fsm->id || !fsm->b_sess_vld)
otg_set_state(fsm, OTG_STATE_B_IDLE);
else if (fsm->b_bus_req && fsm->otg->
gadget->b_hnp_enable && fsm->a_bus_suspend)
otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
break;
case OTG_STATE_B_WAIT_ACON:
if (fsm->a_conn)
otg_set_state(fsm, OTG_STATE_B_HOST);
else if (!fsm->id || !fsm->b_sess_vld)
otg_set_state(fsm, OTG_STATE_B_IDLE);
else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
fsm->b_ase0_brst_tmout = 0;
otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
}
break;
case OTG_STATE_B_HOST:
if (!fsm->id || !fsm->b_sess_vld)
otg_set_state(fsm, OTG_STATE_B_IDLE);
else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
break;
case OTG_STATE_A_IDLE:
if (fsm->id)
otg_set_state(fsm, OTG_STATE_B_IDLE);
else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
fsm->a_srp_det || fsm->adp_change || fsm->power_up))
otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
break;
case OTG_STATE_A_WAIT_VRISE:
if (fsm->a_vbus_vld)
otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
else if (fsm->id || fsm->a_bus_drop ||
fsm->a_wait_vrise_tmout)
otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
break;
case OTG_STATE_A_WAIT_BCON:
if (!fsm->a_vbus_vld)
otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
else if (fsm->b_conn)
otg_set_state(fsm, OTG_STATE_A_HOST);
else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
break;
case OTG_STATE_A_HOST:
if (fsm->id || fsm->a_bus_drop)
otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
fsm->otg->host->b_hnp_enable)
otg_set_state(fsm, OTG_STATE_A_SUSPEND);
else if (!fsm->b_conn)
otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
else if (!fsm->a_vbus_vld)
otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
break;
case OTG_STATE_A_SUSPEND:
if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
else if (fsm->a_bus_req || fsm->b_bus_resume)
otg_set_state(fsm, OTG_STATE_A_HOST);
else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
else if (!fsm->a_vbus_vld)
otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
break;
case OTG_STATE_A_PERIPHERAL:
if (fsm->id || fsm->a_bus_drop)
otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
else if (!fsm->a_vbus_vld)
otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
break;
case OTG_STATE_A_WAIT_VFALL:
if (fsm->a_wait_vfall_tmout)
otg_set_state(fsm, OTG_STATE_A_IDLE);
break;
case OTG_STATE_A_VBUS_ERR:
if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
break;
default:
break;
}
mutex_unlock(&fsm->lock);
VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
return fsm->state_changed;
}
EXPORT_SYMBOL_GPL(otg_statemachine);
MODULE_LICENSE("GPL");
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