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