diff options
Diffstat (limited to 'drivers/usb/common/usb-otg-fsm.c')
| -rw-r--r-- | drivers/usb/common/usb-otg-fsm.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c new file mode 100644 index 000000000..0697fde51 --- /dev/null +++ b/drivers/usb/common/usb-otg-fsm.c @@ -0,0 +1,452 @@ +// 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"); |