| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * otg.c - ChipIdea USB IP core OTG driver |
| * |
| * Copyright (C) 2013-2016 Freescale Semiconductor, Inc. |
| * Copyright 2017 NXP |
| * |
| * 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" |
| #include "host.h" |
| |
| /** |
| * hw_read_otgsc returns otgsc register bits value. |
| * @mask: bitfield mask |
| */ |
| u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask) |
| { |
| struct ci_hdrc_cable *cable; |
| u32 val = hw_read(ci, OP_OTGSC, mask); |
| |
| /* |
| * If using extcon framework for VBUS and/or ID signal |
| * detection overwrite OTGSC register value |
| */ |
| cable = &ci->platdata->vbus_extcon; |
| if (!IS_ERR(cable->edev)) { |
| if (cable->changed) |
| val |= OTGSC_BSVIS; |
| else |
| val &= ~OTGSC_BSVIS; |
| |
| if (cable->connected) |
| val |= OTGSC_BSV; |
| else |
| val &= ~OTGSC_BSV; |
| |
| if (cable->enabled) |
| val |= OTGSC_BSVIE; |
| else |
| val &= ~OTGSC_BSVIE; |
| } |
| |
| cable = &ci->platdata->id_extcon; |
| if (!IS_ERR(cable->edev)) { |
| if (cable->changed) |
| val |= OTGSC_IDIS; |
| else |
| val &= ~OTGSC_IDIS; |
| |
| if (cable->connected) |
| val &= ~OTGSC_ID; /* host */ |
| else |
| val |= OTGSC_ID; /* device */ |
| |
| if (cable->enabled) |
| val |= OTGSC_IDIE; |
| else |
| val &= ~OTGSC_IDIE; |
| } |
| |
| return val & 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) |
| { |
| struct ci_hdrc_cable *cable; |
| |
| cable = &ci->platdata->vbus_extcon; |
| if (!IS_ERR(cable->edev)) { |
| if (data & mask & OTGSC_BSVIS) |
| cable->changed = false; |
| |
| /* Don't enable vbus interrupt if using external notifier */ |
| if (data & mask & OTGSC_BSVIE) { |
| cable->enabled = true; |
| data &= ~OTGSC_BSVIE; |
| } else if (mask & OTGSC_BSVIE) { |
| cable->enabled = false; |
| } |
| } |
| |
| cable = &ci->platdata->id_extcon; |
| if (!IS_ERR(cable->edev)) { |
| if (data & mask & OTGSC_IDIS) |
| cable->changed = false; |
| |
| /* Don't enable id interrupt if using external notifier */ |
| if (data & mask & OTGSC_IDIE) { |
| cable->enabled = true; |
| data &= ~OTGSC_IDIE; |
| } else if (mask & OTGSC_IDIE) { |
| cable->enabled = false; |
| } |
| } |
| |
| 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; |
| } |
| |
| /* |
| * Handling vbus glitch |
| * We only need to consider glitch for without usb connection, |
| * With usb connection, we consider it as real disconnection. |
| * |
| * If the vbus can't be kept above B session valid for timeout value, |
| * we think it is a vbus glitch, otherwise it's a valid vbus. |
| */ |
| #define CI_VBUS_CONNECT_TIMEOUT_MS 300 |
| static int ci_is_vbus_glitch(struct ci_hdrc *ci) |
| { |
| int i; |
| |
| for (i = 0; i < CI_VBUS_CONNECT_TIMEOUT_MS/20; i++) { |
| if (hw_read_otgsc(ci, OTGSC_AVV)) { |
| return 0; |
| } else if (!hw_read_otgsc(ci, OTGSC_BSV)) { |
| dev_warn(ci->dev, "there is a vbus glitch\n"); |
| return 1; |
| } |
| msleep(20); |
| } |
| |
| return 0; |
| } |
| |
| void ci_handle_vbus_connected(struct ci_hdrc *ci) |
| { |
| /* |
| * TODO: if the platform does not supply 5v to udc, or use other way |
| * to supply 5v, it needs to use other conditions to call |
| * usb_gadget_vbus_connect. |
| */ |
| if (!ci->is_otg) |
| return; |
| |
| if (hw_read_otgsc(ci, OTGSC_BSV) && !ci_is_vbus_glitch(ci)) |
| usb_gadget_vbus_connect(&ci->gadget); |
| } |
| |
| void ci_handle_vbus_change(struct ci_hdrc *ci) |
| { |
| if (!ci->is_otg) |
| return; |
| |
| if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active) |
| usb_gadget_vbus_connect(&ci->gadget); |
| else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active) |
| usb_gadget_vbus_disconnect(&ci->gadget); |
| } |
| |
| /** |
| * When we switch to device mode, the vbus value should be lower |
| * than OTGSC_BSV before connecting to host. |
| * |
| * @ci: the controller |
| * |
| * This function returns an error code if timeout |
| */ |
| static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci) |
| { |
| unsigned long elapse = jiffies + msecs_to_jiffies(5000); |
| u32 mask = OTGSC_BSV; |
| |
| while (hw_read_otgsc(ci, mask)) { |
| if (time_after(jiffies, elapse)) { |
| dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n", |
| mask); |
| return -ETIMEDOUT; |
| } |
| msleep(20); |
| } |
| |
| return 0; |
| } |
| |
| void ci_handle_id_switch(struct ci_hdrc *ci) |
| { |
| enum ci_role role; |
| int ret = 0; |
| |
| mutex_lock(&ci->mutex); |
| 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); |
| |
| if (role == CI_ROLE_GADGET && |
| IS_ERR(ci->platdata->vbus_extcon.edev)) |
| /* |
| * Wait vbus lower than OTGSC_BSV before connecting |
| * to host. If connecting status is from an external |
| * connector instead of register, we don't need to |
| * care vbus on the board, since it will not affect |
| * external connector status. |
| */ |
| ret = hw_wait_vbus_lower_bsv(ci); |
| else if (ci->vbus_active) |
| /* |
| * If the role switch happens(e.g. during |
| * system sleep), and we lose vbus drop |
| * event, disconnect gadget for it before |
| * start host. |
| */ |
| usb_gadget_vbus_disconnect(&ci->gadget); |
| |
| ci_role_start(ci, role); |
| /* vbus change may have already occurred */ |
| if (role == CI_ROLE_GADGET) |
| ci_handle_vbus_change(ci); |
| |
| /* |
| * If the role switch happens(e.g. during system |
| * sleep) and vbus keeps on afterwards, we connect |
| * gadget as vbus connect event lost. |
| */ |
| if (ret == -ETIMEDOUT) |
| usb_gadget_vbus_connect(&ci->gadget); |
| } |
| mutex_unlock(&ci->mutex); |
| } |
| |
| static void ci_handle_vbus_glitch(struct ci_hdrc *ci) |
| { |
| bool valid_vbus_change = false; |
| |
| if (hw_read_otgsc(ci, OTGSC_BSV)) { |
| if (!ci_is_vbus_glitch(ci)) { |
| if (ci_otg_is_fsm_mode(ci)) { |
| ci->fsm.b_sess_vld = 1; |
| ci->fsm.b_ssend_srp = 0; |
| otg_del_timer(&ci->fsm, B_SSEND_SRP); |
| otg_del_timer(&ci->fsm, B_SRP_FAIL); |
| } |
| valid_vbus_change = true; |
| } |
| } else { |
| if (ci->vbus_active && !ci_otg_is_fsm_mode(ci)) |
| valid_vbus_change = true; |
| } |
| |
| if (valid_vbus_change) { |
| ci->b_sess_valid_event = true; |
| ci_otg_queue_work(ci); |
| } |
| } |
| |
| /** |
| * 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->vbus_glitch_check_event) { |
| ci->vbus_glitch_check_event = false; |
| pm_runtime_get_sync(ci->dev); |
| ci_handle_vbus_glitch(ci); |
| pm_runtime_put_sync(ci->dev); |
| enable_irq(ci->irq); |
| return; |
| } |
| |
| if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) { |
| enable_irq(ci->irq); |
| return; |
| } |
| |
| pm_runtime_get_sync(ci->dev); |
| 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__); |
| pm_runtime_put_sync(ci->dev); |
| |
| 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_freezable_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) |
| { |
| /* 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->wq) { |
| flush_workqueue(ci->wq); |
| destroy_workqueue(ci->wq); |
| ci->wq = NULL; |
| } |
| if (ci_otg_is_fsm_mode(ci)) |
| ci_hdrc_otg_fsm_remove(ci); |
| } |