// SPDX-License-Identifier: GPL-2.0
/*
* Cadence USBSS and USBSSP DRD Driver.
*
* Copyright (C) 2018-2019 Cadence.
* Copyright (C) 2017-2018 NXP
* Copyright (C) 2019 Texas Instruments
*
* Author: Peter Chen <[email protected]>
* Pawel Laszczak <[email protected]>
* Roger Quadros <[email protected]>
*/
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include "core.h"
#include "host-export.h"
#include "drd.h"
static int cdns_idle_init(struct cdns *cdns);
static int cdns_role_start(struct cdns *cdns, enum usb_role role)
{
int ret;
if (WARN_ON(role > USB_ROLE_DEVICE))
return 0;
mutex_lock(&cdns->mutex);
cdns->role = role;
mutex_unlock(&cdns->mutex);
if (!cdns->roles[role])
return -ENXIO;
if (cdns->roles[role]->state == CDNS_ROLE_STATE_ACTIVE)
return 0;
mutex_lock(&cdns->mutex);
ret = cdns->roles[role]->start(cdns);
if (!ret)
cdns->roles[role]->state = CDNS_ROLE_STATE_ACTIVE;
mutex_unlock(&cdns->mutex);
return ret;
}
static void cdns_role_stop(struct cdns *cdns)
{
enum usb_role role = cdns->role;
if (WARN_ON(role > USB_ROLE_DEVICE))
return;
if (cdns->roles[role]->state == CDNS_ROLE_STATE_INACTIVE)
return;
mutex_lock(&cdns->mutex);
cdns->roles[role]->stop(cdns);
cdns->roles[role]->state = CDNS_ROLE_STATE_INACTIVE;
mutex_unlock(&cdns->mutex);
}
static void cdns_exit_roles(struct cdns *cdns)
{
cdns_role_stop(cdns);
cdns_drd_exit(cdns);
}
/**
* cdns_core_init_role - initialize role of operation
* @cdns: Pointer to cdns structure
*
* Returns 0 on success otherwise negative errno
*/
static int cdns_core_init_role(struct cdns *cdns)
{
struct device *dev = cdns->dev;
enum usb_dr_mode best_dr_mode;
enum usb_dr_mode dr_mode;
int ret;
dr_mode = usb_get_dr_mode(dev);
cdns->role = USB_ROLE_NONE;
/*
* If driver can't read mode by means of usb_get_dr_mode function then
* chooses mode according with Kernel configuration. This setting
* can be restricted later depending on strap pin configuration.
*/
if (dr_mode == USB_DR_MODE_UNKNOWN) {
if (cdns->version == CDNSP_CONTROLLER_V2) {
if (IS_ENABLED(CONFIG_USB_CDNSP_HOST) &&
IS_ENABLED(CONFIG_USB_CDNSP_GADGET))
dr_mode = USB_DR_MODE_OTG;
else if (IS_ENABLED(CONFIG_USB_CDNSP_HOST))
dr_mode = USB_DR_MODE_HOST;
else if (IS_ENABLED(CONFIG_USB_CDNSP_GADGET))
dr_mode = USB_DR_MODE_PERIPHERAL;
} else {
if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
dr_mode = USB_DR_MODE_OTG;
else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
dr_mode = USB_DR_MODE_HOST;
else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
dr_mode = USB_DR_MODE_PERIPHERAL;
}
}
/*
* At this point cdns->dr_mode contains strap configuration.
* Driver try update this setting considering kernel configuration
*/
best_dr_mode = cdns->dr_mode;
ret = cdns_idle_init(cdns);
if (ret)
return ret;
if (dr_mode == USB_DR_MODE_OTG) {
best_dr_mode = cdns->dr_mode;
} else if (cdns->dr_mode == USB_DR_MODE_OTG) {
best_dr_mode = dr_mode;
} else if (cdns->dr_mode != dr_mode) {
dev_err(dev, "Incorrect DRD configuration\n");
return -EINVAL;
}
dr_mode = best_dr_mode;
if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
if ((cdns->version == CDNSP_CONTROLLER_V2 &&
IS_ENABLED(CONFIG_USB_CDNSP_HOST)) ||
(cdns->version < CDNSP_CONTROLLER_V2 &&
IS_ENABLED(CONFIG_USB_CDNS3_HOST)))
ret = cdns_host_init(cdns);
else
ret = -ENXIO;
if (ret) {
dev_err(dev, "Host initialization failed with %d\n",
ret);
goto err;
}
}
if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
if (cdns->gadget_init)
ret = cdns->gadget_init(cdns);
else
ret = -ENXIO;
if (ret) {
dev_err(dev, "Device initialization failed with %d\n",
ret);
goto err;
}
}
cdns->dr_mode = dr_mode;
ret = cdns_drd_update_mode(cdns);
if (ret)
goto err;
/* Initialize idle role to start with */
ret = cdns_role_start(cdns, USB_ROLE_NONE);
if (ret)
goto err;
switch (cdns->dr_mode) {
case USB_DR_MODE_OTG:
ret = cdns_hw_role_switch(cdns);
if (ret)
goto err;
break;
case USB_DR_MODE_PERIPHERAL:
ret = cdns_role_start(cdns, USB_ROLE_DEVICE);
if (ret)
goto err;
break;
case USB_DR_MODE_HOST:
ret = cdns_role_start(cdns, USB_ROLE_HOST);
if (ret)
goto err;
break;
default:
ret = -EINVAL;
goto err;
}
return 0;
err:
cdns_exit_roles(cdns);
return ret;
}
/**
* cdns_hw_role_state_machine - role switch state machine based on hw events.
* @cdns: Pointer to controller structure.
*
* Returns next role to be entered based on hw events.
*/
static enum usb_role cdns_hw_role_state_machine(struct cdns *cdns)
{
enum usb_role role = USB_ROLE_NONE;
int id, vbus;
if (cdns->dr_mode != USB_DR_MODE_OTG) {
if (cdns_is_host(cdns))
role = USB_ROLE_HOST;
if (cdns_is_device(cdns))
role = USB_ROLE_DEVICE;
return role;
}
id = cdns_get_id(cdns);
vbus = cdns_get_vbus(cdns);
/*
* Role change state machine
* Inputs: ID, VBUS
* Previous state: cdns->role
* Next state: role
*/
role = cdns->role;
switch (role) {
case USB_ROLE_NONE:
/*
* Driver treats USB_ROLE_NONE synonymous to IDLE state from
* controller specification.
*/
if (!id)
role = USB_ROLE_HOST;
else if (vbus)
role = USB_ROLE_DEVICE;
break;
case USB_ROLE_HOST: /* from HOST, we can only change to NONE */
if (id)
role = USB_ROLE_NONE;
break;
case USB_ROLE_DEVICE: /* from GADGET, we can only change to NONE*/
if (!vbus)
role = USB_ROLE_NONE;
break;
}
dev_dbg(cdns->dev, "role %d -> %d\n", cdns->role, role);
return role;
}
static int cdns_idle_role_start(struct cdns *cdns)
{
return 0;
}
static void cdns_idle_role_stop(struct cdns *cdns)
{
/* Program Lane swap and bring PHY out of RESET */
phy_reset(cdns->usb3_phy);
}
static int cdns_idle_init(struct cdns *cdns)
{
struct cdns_role_driver *rdrv;
rdrv = devm_kzalloc(cdns->dev, sizeof(*rdrv), GFP_KERNEL);
if (!rdrv)
return -ENOMEM;
rdrv->start = cdns_idle_role_start;
rdrv->stop = cdns_idle_role_stop;
rdrv->state = CDNS_ROLE_STATE_INACTIVE;
rdrv->suspend = NULL;
rdrv->resume = NULL;
rdrv->name = "idle";
cdns->roles[USB_ROLE_NONE] = rdrv;
return 0;
}
/**
* cdns_hw_role_switch - switch roles based on HW state
* @cdns: controller
*/
int cdns_hw_role_switch(struct cdns *cdns)
{
enum usb_role real_role, current_role;
int ret = 0;
/* Depends on role switch class */
if (cdns->role_sw)
return 0;
pm_runtime_get_sync(cdns->dev);
current_role = cdns->role;
real_role = cdns_hw_role_state_machine(cdns);
/* Do nothing if nothing changed */
if (current_role == real_role)
goto exit;
cdns_role_stop(cdns);
dev_dbg(cdns->dev, "Switching role %d -> %d", current_role, real_role);
ret = cdns_role_start(cdns, real_role);
if (ret) {
/* Back to current role */
dev_err(cdns->dev, "set %d has failed, back to %d\n",
real_role, current_role);
ret = cdns_role_start(cdns, current_role);
if (ret)
dev_err(cdns->dev, "back to %d failed too\n",
current_role);
}
exit:
pm_runtime_put_sync(cdns->dev);
return ret;
}
/**
* cdns_role_get - get current role of controller.
*
* @sw: pointer to USB role switch structure
*
* Returns role
*/
static enum usb_role cdns_role_get(struct usb_role_switch *sw)
{
struct cdns *cdns = usb_role_switch_get_drvdata(sw);
return cdns->role;
}
/**
* cdns_role_set - set current role of controller.
*
* @sw: pointer to USB role switch structure
* @role: the previous role
* Handles below events:
* - Role switch for dual-role devices
* - USB_ROLE_GADGET <--> USB_ROLE_NONE for peripheral-only devices
*/
static int cdns_role_set(struct usb_role_switch *sw, enum usb_role role)
{
struct cdns *cdns = usb_role_switch_get_drvdata(sw);
int ret = 0;
pm_runtime_get_sync(cdns->dev);
if (cdns->role == role)
goto pm_put;
if (cdns->dr_mode == USB_DR_MODE_HOST) {
switch (role) {
case USB_ROLE_NONE:
case USB_ROLE_HOST:
break;
default:
goto pm_put;
}
}
if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL) {
switch (role) {
case USB_ROLE_NONE:
case USB_ROLE_DEVICE:
break;
default:
goto pm_put;
}
}
cdns_role_stop(cdns);
ret = cdns_role_start(cdns, role);
if (ret)
dev_err(cdns->dev, "set role %d has failed\n", role);
pm_put:
pm_runtime_put_sync(cdns->dev);
return ret;
}
/**
* cdns_wakeup_irq - interrupt handler for wakeup events
* @irq: irq number for cdns3/cdnsp core device
* @data: structure of cdns
*
* Returns IRQ_HANDLED or IRQ_NONE
*/
static irqreturn_t cdns_wakeup_irq(int irq, void *data)
{
struct cdns *cdns = data;
if (cdns->in_lpm) {
disable_irq_nosync(irq);
cdns->wakeup_pending = true;
if ((cdns->role == USB_ROLE_HOST) && cdns->host_dev)
pm_request_resume(&cdns->host_dev->dev);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/**
* cdns_init - probe for cdns3/cdnsp core device
* @cdns: Pointer to cdns structure.
*
* Returns 0 on success otherwise negative errno
*/
int cdns_init(struct cdns *cdns)
{
struct device *dev = cdns->dev;
int ret;
ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (ret) {
dev_err(dev, "error setting dma mask: %d\n", ret);
return ret;
}
mutex_init(&cdns->mutex);
if (device_property_read_bool(dev, "usb-role-switch")) {
struct usb_role_switch_desc sw_desc = { };
sw_desc.set = cdns_role_set;
sw_desc.get = cdns_role_get;
sw_desc.allow_userspace_control = true;
sw_desc.driver_data = cdns;
sw_desc.fwnode = dev->fwnode;
cdns->role_sw = usb_role_switch_register(dev, &sw_desc);
if (IS_ERR(cdns->role_sw)) {
dev_warn(dev, "Unable to register Role Switch\n");
return PTR_ERR(cdns->role_sw);
}
}
if (cdns->wakeup_irq) {
ret = devm_request_irq(cdns->dev, cdns->wakeup_irq,
cdns_wakeup_irq,
IRQF_SHARED,
dev_name(cdns->dev), cdns);
if (ret) {
dev_err(cdns->dev, "couldn't register wakeup irq handler\n");
goto role_switch_unregister;
}
}
ret = cdns_drd_init(cdns);
if (ret)
goto init_failed;
ret = cdns_core_init_role(cdns);
if (ret)
goto init_failed;
spin_lock_init(&cdns->lock);
dev_dbg(dev, "Cadence USB3 core: probe succeed\n");
return 0;
init_failed:
cdns_drd_exit(cdns);
role_switch_unregister:
if (cdns->role_sw)
usb_role_switch_unregister(cdns->role_sw);
return ret;
}
EXPORT_SYMBOL_GPL(cdns_init);
/**
* cdns_remove - unbind drd driver and clean up
* @cdns: Pointer to cdns structure.
*
* Returns 0 on success otherwise negative errno
*/
int cdns_remove(struct cdns *cdns)
{
cdns_exit_roles(cdns);
usb_role_switch_unregister(cdns->role_sw);
return 0;
}
EXPORT_SYMBOL_GPL(cdns_remove);
#ifdef CONFIG_PM_SLEEP
int cdns_suspend(struct cdns *cdns)
{
struct device *dev = cdns->dev;
unsigned long flags;
if (pm_runtime_status_suspended(dev))
pm_runtime_resume(dev);
if (cdns->roles[cdns->role]->suspend) {
spin_lock_irqsave(&cdns->lock, flags);
cdns->roles[cdns->role]->suspend(cdns, false);
spin_unlock_irqrestore(&cdns->lock, flags);
}
return 0;
}
EXPORT_SYMBOL_GPL(cdns_suspend);
int cdns_resume(struct cdns *cdns)
{
enum usb_role real_role;
bool role_changed = false;
int ret = 0;
if (cdns_power_is_lost(cdns)) {
if (cdns->role_sw) {
cdns->role = cdns_role_get(cdns->role_sw);
} else {
real_role = cdns_hw_role_state_machine(cdns);
if (real_role != cdns->role) {
ret = cdns_hw_role_switch(cdns);
if (ret)
return ret;
role_changed = true;
}
}
if (!role_changed) {
if (cdns->role == USB_ROLE_HOST)
ret = cdns_drd_host_on(cdns);
else if (cdns->role == USB_ROLE_DEVICE)
ret = cdns_drd_gadget_on(cdns);
if (ret)
return ret;
}
}
if (cdns->roles[cdns->role]->resume)
cdns->roles[cdns->role]->resume(cdns, cdns_power_is_lost(cdns));
return 0;
}
EXPORT_SYMBOL_GPL(cdns_resume);
void cdns_set_active(struct cdns *cdns, u8 set_active)
{
struct device *dev = cdns->dev;
if (set_active) {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
}
return;
}
EXPORT_SYMBOL_GPL(cdns_set_active);
#endif /* CONFIG_PM_SLEEP */
MODULE_AUTHOR("Peter Chen <[email protected]>");
MODULE_AUTHOR("Pawel Laszczak <[email protected]>");
MODULE_AUTHOR("Roger Quadros <[email protected]>");
MODULE_DESCRIPTION("Cadence USBSS and USBSSP DRD Driver");
MODULE_LICENSE("GPL");
Codebase Browser
linux