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    Subject[PATCH v4 5/6] usb: roles: add USB Type-B GPIO connector driver
    Date
    Due to the requirement of usb-connector.txt binding, the old way
    using extcon to support USB Dual-Role switch is now deprecated
    when use Type-B connector.
    This patch introduces a driver of Type-B connector which typically
    uses an input GPIO to detect USB ID pin, and try to replace the
    function provided by extcon-usb-gpio driver

    Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
    ---
    v4 changes:
    1. remove linux/gpio.h suggested by Linus
    2. put node when error happens

    v3 changes:
    1. treat bype-B connector as a virtual device;
    2. change file name again

    v2 changes:
    1. file name is changed
    2. use new compatible
    ---
    drivers/usb/roles/Kconfig | 11 +
    drivers/usb/roles/Makefile | 1 +
    drivers/usb/roles/typeb-conn-gpio.c | 305 ++++++++++++++++++++++++++++
    3 files changed, 317 insertions(+)
    create mode 100644 drivers/usb/roles/typeb-conn-gpio.c

    diff --git a/drivers/usb/roles/Kconfig b/drivers/usb/roles/Kconfig
    index f8b31aa67526..d1156e18a81a 100644
    --- a/drivers/usb/roles/Kconfig
    +++ b/drivers/usb/roles/Kconfig
    @@ -26,4 +26,15 @@ config USB_ROLES_INTEL_XHCI
    To compile the driver as a module, choose M here: the module will
    be called intel-xhci-usb-role-switch.

    +config TYPEB_CONN_GPIO
    + tristate "USB Type-B GPIO Connector"
    + depends on GPIOLIB
    + help
    + The driver supports USB role switch between host and device via GPIO
    + based USB cable detection, used typically if an input GPIO is used
    + to detect USB ID pin.
    +
    + To compile the driver as a module, choose M here: the module will
    + be called typeb-conn-gpio.ko
    +
    endif # USB_ROLE_SWITCH
    diff --git a/drivers/usb/roles/Makefile b/drivers/usb/roles/Makefile
    index 757a7d2797eb..5d5620d9d113 100644
    --- a/drivers/usb/roles/Makefile
    +++ b/drivers/usb/roles/Makefile
    @@ -3,3 +3,4 @@
    obj-$(CONFIG_USB_ROLE_SWITCH) += roles.o
    roles-y := class.o
    obj-$(CONFIG_USB_ROLES_INTEL_XHCI) += intel-xhci-usb-role-switch.o
    +obj-$(CONFIG_TYPEB_CONN_GPIO) += typeb-conn-gpio.o
    diff --git a/drivers/usb/roles/typeb-conn-gpio.c b/drivers/usb/roles/typeb-conn-gpio.c
    new file mode 100644
    index 000000000000..097d2ca12a12
    --- /dev/null
    +++ b/drivers/usb/roles/typeb-conn-gpio.c
    @@ -0,0 +1,305 @@
    +// SPDX-License-Identifier: GPL-2.0
    +/*
    + * USB Type-B GPIO Connector Driver
    + *
    + * Copyright (C) 2019 MediaTek Inc.
    + *
    + * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
    + *
    + * Some code borrowed from drivers/extcon/extcon-usb-gpio.c
    + */
    +
    +#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/of_graph.h>
    +#include <linux/pinctrl/consumer.h>
    +#include <linux/platform_device.h>
    +#include <linux/regulator/consumer.h>
    +#include <linux/usb/role.h>
    +
    +#define USB_GPIO_DEB_MS 20 /* ms */
    +#define USB_GPIO_DEB_US ((USB_GPIO_DEB_MS) * 1000) /* us */
    +
    +#define USB_CONN_IRQF \
    + (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)
    +
    +struct usb_conn_info {
    + struct device *dev;
    + 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;
    +};
    +
    +/**
    + * "DEVICE" = VBUS and "HOST" = !ID, so we have:
    + * Both "DEVICE" and "HOST" can't be set as active at the same time
    + * so if "HOST" is active (i.e. ID is 0) we keep "DEVICE" inactive
    + * even if VBUS is on.
    + *
    + * Role | ID | VBUS
    + * ------------------------------------
    + * [1] DEVICE | H | H
    + * [2] NONE | H | L
    + * [3] HOST | L | H
    + * [4] HOST | L | L
    + *
    + * In case we have only one of these signals:
    + * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1
    + * - ID only - we want to distinguish between [1] and [4], so VBUS = ID
    + */
    +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);
    +
    + /* check ID and VBUS */
    + 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 %d/%d, gpios: id %d, vbus %d\n",
    + info->last_role, role, id, vbus);
    +
    + if (info->last_role == role) {
    + dev_warn(info->dev, "repeated role: %d\n", role);
    + return;
    + }
    +
    + if (info->last_role == USB_ROLE_HOST)
    + 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) {
    + ret = regulator_enable(info->vbus);
    + if (ret)
    + dev_err(info->dev, "enable vbus regulator failed\n");
    + }
    +
    + info->last_role = role;
    +
    + dev_dbg(info->dev, "vbus regulator is %s\n",
    + regulator_is_enabled(info->vbus) ? "enabled" : "disabled");
    +}
    +
    +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 int usb_conn_probe(struct platform_device *pdev)
    +{
    + struct device *dev = &pdev->dev;
    + struct device_node *np = dev->of_node;
    + struct device_node *parent;
    + struct device_node *child;
    + struct usb_conn_info *info;
    + int ret = 0;
    +
    + if (!np)
    + return -EINVAL;
    +
    + info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
    + if (!info)
    + return -ENOMEM;
    +
    + info->dev = dev;
    +
    + child = of_get_child_by_name(np, "connector");
    + if (!child) {
    + dev_err(dev, "failed to find connector node\n");
    + return -ENODEV;
    + }
    +
    + info->id_gpiod = devm_gpiod_get_from_of_node(
    + dev, child, "id-gpios", 0, GPIOD_IN, "idpin");
    + if (IS_ERR(info->id_gpiod)) {
    + of_node_put(child);
    + return PTR_ERR(info->id_gpiod);
    + }
    +
    + info->vbus_gpiod = devm_gpiod_get_from_of_node(
    + dev, child, "vbus-gpios", 0, GPIOD_IN,
    + "vbuspin");
    + if (IS_ERR(info->vbus_gpiod)) {
    + of_node_put(child);
    + return PTR_ERR(info->vbus_gpiod);
    + }
    +
    + if (!info->id_gpiod && !info->vbus_gpiod) {
    + dev_err(dev, "failed to get gpios\n");
    + return -ENODEV;
    + }
    +
    + of_node_put(child);
    +
    + 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(dev, "vbus");
    + if (IS_ERR(info->vbus)) {
    + dev_err(dev, "failed to get vbus\n");
    + return PTR_ERR(info->vbus);
    + }
    +
    + child = of_graph_get_endpoint_by_regs(np, -1, 0);
    + parent = of_graph_get_remote_port_parent(child);
    + info->role_sw = fwnode_usb_role_switch_get(of_fwnode_handle(parent));
    + of_node_put(child);
    + of_node_put(parent);
    + if (IS_ERR(info->role_sw)) {
    + dev_err(dev, "failed to get role switch\n");
    + return PTR_ERR(info->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");
    + return info->id_irq;
    + }
    +
    + 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");
    + return ret;
    + }
    + }
    +
    + 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");
    + return info->vbus_irq;
    + }
    +
    + 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");
    + return ret;
    + }
    + }
    +
    + platform_set_drvdata(pdev, info);
    +
    + /* Perform initial detection */
    + usb_conn_queue_dwork(info, 0);
    +
    + return 0;
    +}
    +
    +static int 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->last_role == USB_ROLE_HOST)
    + regulator_disable(info->vbus);
    +
    + usb_role_switch_put(info->role_sw);
    +
    + return 0;
    +}
    +
    +static int __maybe_unused usb_conn_suspend(struct device *dev)
    +{
    + struct usb_conn_info *info = dev_get_drvdata(dev);
    +
    + 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);
    +
    + 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);
    +
    +#define DEV_PMS_OPS (IS_ENABLED(CONFIG_PM_SLEEP) ? &usb_conn_pm_ops : NULL)
    +
    +static const struct of_device_id usb_conn_dt_match[] = {
    + { .compatible = "linux,typeb-conn-gpio", },
    + { }
    +};
    +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 = "typeb-conn-gpio",
    + .pm = DEV_PMS_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 Type-B GPIO connector driver");
    +MODULE_LICENSE("GPL v2");
    --
    2.21.0
    \
     
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      Last update: 2019-04-26 08:49    [W:6.252 / U:0.024 seconds]
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