#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regulator/consumer.h>
#include <linux/string_choices.h>
#include <linux/usb/role.h>
#include <linux/idr.h>
static DEFINE_IDA(usb_conn_ida);
#define USB_GPIO_DEB_MS 20
#define USB_GPIO_DEB_US ((USB_GPIO_DEB_MS) * 1000)
#define USB_CONN_IRQF \
(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)
struct usb_conn_info {
struct device *dev;
int conn_id;
struct usb_role_switch *role_sw;
enum usb_role last_role;
struct regulator *vbus;
struct delayed_work dw_det;
unsigned long debounce_jiffies;
struct gpio_desc *id_gpiod;
struct gpio_desc *vbus_gpiod;
int id_irq;
int vbus_irq;
struct power_supply_desc desc;
struct power_supply *charger;
bool initial_detection;
};
static void usb_conn_detect_cable(struct work_struct *work)
{
struct usb_conn_info *info;
enum usb_role role;
int id, vbus, ret;
info = container_of(to_delayed_work(work),
struct usb_conn_info, dw_det);
id = info->id_gpiod ?
gpiod_get_value_cansleep(info->id_gpiod) : 1;
vbus = info->vbus_gpiod ?
gpiod_get_value_cansleep(info->vbus_gpiod) : id;
if (!id)
role = USB_ROLE_HOST;
else if (vbus)
role = USB_ROLE_DEVICE;
else
role = USB_ROLE_NONE;
dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n",
usb_role_string(info->last_role), usb_role_string(role), id, vbus);
if (!info->initial_detection && info->last_role == role) {
dev_warn(info->dev, "repeated role: %s\n", usb_role_string(role));
return;
}
info->initial_detection = false;
if (info->last_role == USB_ROLE_HOST && info->vbus)
regulator_disable(info->vbus);
ret = usb_role_switch_set_role(info->role_sw, role);
if (ret)
dev_err(info->dev, "failed to set role: %d\n", ret);
if (role == USB_ROLE_HOST && info->vbus) {
ret = regulator_enable(info->vbus);
if (ret)
dev_err(info->dev, "enable vbus regulator failed\n");
}
info->last_role = role;
if (info->vbus)
dev_dbg(info->dev, "vbus regulator is %s\n",
str_enabled_disabled(regulator_is_enabled(info->vbus)));
power_supply_changed(info->charger);
}
static void usb_conn_queue_dwork(struct usb_conn_info *info,
unsigned long delay)
{
queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
}
static irqreturn_t usb_conn_isr(int irq, void *dev_id)
{
struct usb_conn_info *info = dev_id;
usb_conn_queue_dwork(info, info->debounce_jiffies);
return IRQ_HANDLED;
}
static enum power_supply_property usb_charger_properties[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static int usb_charger_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct usb_conn_info *info = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = info->last_role == USB_ROLE_DEVICE;
break;
default:
return -EINVAL;
}
return 0;
}
static int usb_conn_psy_register(struct usb_conn_info *info)
{
struct device *dev = info->dev;
struct power_supply_desc *desc = &info->desc;
struct power_supply_config cfg = {
.fwnode = dev_fwnode(dev),
};
info->conn_id = ida_alloc(&usb_conn_ida, GFP_KERNEL);
if (info->conn_id < 0)
return info->conn_id;
desc->name = devm_kasprintf(dev, GFP_KERNEL, "usb-charger-%d",
info->conn_id);
if (!desc->name) {
ida_free(&usb_conn_ida, info->conn_id);
return -ENOMEM;
}
desc->properties = usb_charger_properties;
desc->num_properties = ARRAY_SIZE(usb_charger_properties);
desc->get_property = usb_charger_get_property;
desc->type = POWER_SUPPLY_TYPE_USB;
cfg.drv_data = info;
info->charger = devm_power_supply_register(dev, desc, &cfg);
if (IS_ERR(info->charger)) {
dev_err(dev, "Unable to register charger %d\n", info->conn_id);
ida_free(&usb_conn_ida, info->conn_id);
}
return PTR_ERR_OR_ZERO(info->charger);
}
static int usb_conn_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct usb_conn_info *info;
int ret = 0;
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->dev = dev;
info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
if (IS_ERR(info->id_gpiod))
return PTR_ERR(info->id_gpiod);
info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
if (IS_ERR(info->vbus_gpiod))
return PTR_ERR(info->vbus_gpiod);
if (!info->id_gpiod && !info->vbus_gpiod) {
dev_err(dev, "failed to get gpios\n");
return -ENODEV;
}
if (info->id_gpiod)
ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
if (!ret && info->vbus_gpiod)
ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
if (ret < 0)
info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
info->vbus = devm_regulator_get_optional(dev, "vbus");
if (PTR_ERR(info->vbus) == -ENODEV)
info->vbus = NULL;
if (IS_ERR(info->vbus))
return dev_err_probe(dev, PTR_ERR(info->vbus), "failed to get vbus\n");
info->role_sw = usb_role_switch_get(dev);
if (IS_ERR(info->role_sw))
return dev_err_probe(dev, PTR_ERR(info->role_sw),
"failed to get role switch\n");
ret = usb_conn_psy_register(info);
if (ret)
goto put_role_sw;
if (info->id_gpiod) {
info->id_irq = gpiod_to_irq(info->id_gpiod);
if (info->id_irq < 0) {
dev_err(dev, "failed to get ID IRQ\n");
ret = info->id_irq;
goto put_role_sw;
}
ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
usb_conn_isr, USB_CONN_IRQF,
pdev->name, info);
if (ret < 0) {
dev_err(dev, "failed to request ID IRQ\n");
goto put_role_sw;
}
}
if (info->vbus_gpiod) {
info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
if (info->vbus_irq < 0) {
dev_err(dev, "failed to get VBUS IRQ\n");
ret = info->vbus_irq;
goto put_role_sw;
}
ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
usb_conn_isr, USB_CONN_IRQF,
pdev->name, info);
if (ret < 0) {
dev_err(dev, "failed to request VBUS IRQ\n");
goto put_role_sw;
}
}
platform_set_drvdata(pdev, info);
device_set_wakeup_capable(&pdev->dev, true);
info->initial_detection = true;
usb_conn_queue_dwork(info, 0);
return 0;
put_role_sw:
usb_role_switch_put(info->role_sw);
return ret;
}
static void usb_conn_remove(struct platform_device *pdev)
{
struct usb_conn_info *info = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&info->dw_det);
if (info->charger)
ida_free(&usb_conn_ida, info->conn_id);
if (info->last_role == USB_ROLE_HOST && info->vbus)
regulator_disable(info->vbus);
usb_role_switch_put(info->role_sw);
}
static int __maybe_unused usb_conn_suspend(struct device *dev)
{
struct usb_conn_info *info = dev_get_drvdata(dev);
if (device_may_wakeup(dev)) {
if (info->id_gpiod)
enable_irq_wake(info->id_irq);
if (info->vbus_gpiod)
enable_irq_wake(info->vbus_irq);
return 0;
}
if (info->id_gpiod)
disable_irq(info->id_irq);
if (info->vbus_gpiod)
disable_irq(info->vbus_irq);
pinctrl_pm_select_sleep_state(dev);
return 0;
}
static int __maybe_unused usb_conn_resume(struct device *dev)
{
struct usb_conn_info *info = dev_get_drvdata(dev);
if (device_may_wakeup(dev)) {
if (info->id_gpiod)
disable_irq_wake(info->id_irq);
if (info->vbus_gpiod)
disable_irq_wake(info->vbus_irq);
return 0;
}
pinctrl_pm_select_default_state(dev);
if (info->id_gpiod)
enable_irq(info->id_irq);
if (info->vbus_gpiod)
enable_irq(info->vbus_irq);
usb_conn_queue_dwork(info, 0);
return 0;
}
static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
usb_conn_suspend, usb_conn_resume);
static const struct of_device_id usb_conn_dt_match[] = {
{ .compatible = "gpio-usb-b-connector", },
{ }
};
MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
static struct platform_driver usb_conn_driver = {
.probe = usb_conn_probe,
.remove = usb_conn_remove,
.driver = {
.name = "usb-conn-gpio",
.pm = &usb_conn_pm_ops,
.of_match_table = usb_conn_dt_match,
},
};
module_platform_driver(usb_conn_driver);
MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
MODULE_DESCRIPTION("USB GPIO based connection detection driver");
MODULE_LICENSE("GPL v2");
