usb: common: add USB GPIO based connection detection driver
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 USB GPIO based connection detection driver, used to support Type-B connector which typically uses an input GPIO to detect USB ID pin, and try to replace the function provided by the extcon-usb-gpio driver Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Tested-by: Nagarjuna Kristam <nkristam@nvidia.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/1567070558-29417-11-git-send-email-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chunfeng Yun
Greg Kroah-Hartman
parent
12b591bccc
commit
4602f3bff2
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@ -36,3 +36,16 @@ config USB_ULPI_BUS
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To compile this driver as a module, choose M here: the module will
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be called ulpi.
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config USB_CONN_GPIO
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tristate "USB GPIO Based Connection Detection Driver"
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depends on GPIOLIB
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select USB_ROLE_SWITCH
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help
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The driver supports USB role switch between host and device via GPIO
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based USB cable detection, used typically if an input GPIO is used
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to detect USB ID pin, and another input GPIO may be also used to detect
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Vbus pin at the same time, it also can be used to enable/disable
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device if an input GPIO is only used to detect Vbus pin.
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To compile the driver as a module, choose M here: the module will
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be called usb-conn-gpio.ko
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@ -8,5 +8,6 @@ usb-common-y += common.o
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usb-common-$(CONFIG_TRACING) += debug.o
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usb-common-$(CONFIG_USB_LED_TRIG) += led.o
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obj-$(CONFIG_USB_CONN_GPIO) += usb-conn-gpio.o
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obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o
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obj-$(CONFIG_USB_ULPI_BUS) += ulpi.o
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@ -0,0 +1,284 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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* USB GPIO Based Connection Detection Driver
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*
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* Copyright (C) 2019 MediaTek Inc.
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*
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* Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
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*
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* Some code borrowed from drivers/extcon/extcon-usb-gpio.c
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*/
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#include <linux/device.h>
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#include <linux/gpio/consumer.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#include <linux/usb/role.h>
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#define USB_GPIO_DEB_MS 20 /* ms */
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#define USB_GPIO_DEB_US ((USB_GPIO_DEB_MS) * 1000) /* us */
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#define USB_CONN_IRQF \
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(IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT)
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struct usb_conn_info {
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struct device *dev;
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struct usb_role_switch *role_sw;
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enum usb_role last_role;
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struct regulator *vbus;
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struct delayed_work dw_det;
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unsigned long debounce_jiffies;
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struct gpio_desc *id_gpiod;
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struct gpio_desc *vbus_gpiod;
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int id_irq;
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int vbus_irq;
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};
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/**
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* "DEVICE" = VBUS and "HOST" = !ID, so we have:
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* Both "DEVICE" and "HOST" can't be set as active at the same time
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* so if "HOST" is active (i.e. ID is 0) we keep "DEVICE" inactive
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* even if VBUS is on.
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*
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* Role | ID | VBUS
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* ------------------------------------
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* [1] DEVICE | H | H
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* [2] NONE | H | L
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* [3] HOST | L | H
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* [4] HOST | L | L
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*
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* In case we have only one of these signals:
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* - VBUS only - we want to distinguish between [1] and [2], so ID is always 1
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* - ID only - we want to distinguish between [1] and [4], so VBUS = ID
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*/
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static void usb_conn_detect_cable(struct work_struct *work)
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{
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struct usb_conn_info *info;
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enum usb_role role;
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int id, vbus, ret;
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info = container_of(to_delayed_work(work),
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struct usb_conn_info, dw_det);
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/* check ID and VBUS */
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id = info->id_gpiod ?
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gpiod_get_value_cansleep(info->id_gpiod) : 1;
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vbus = info->vbus_gpiod ?
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gpiod_get_value_cansleep(info->vbus_gpiod) : id;
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if (!id)
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role = USB_ROLE_HOST;
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else if (vbus)
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role = USB_ROLE_DEVICE;
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else
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role = USB_ROLE_NONE;
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dev_dbg(info->dev, "role %d/%d, gpios: id %d, vbus %d\n",
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info->last_role, role, id, vbus);
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if (info->last_role == role) {
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dev_warn(info->dev, "repeated role: %d\n", role);
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return;
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}
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if (info->last_role == USB_ROLE_HOST)
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regulator_disable(info->vbus);
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ret = usb_role_switch_set_role(info->role_sw, role);
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if (ret)
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dev_err(info->dev, "failed to set role: %d\n", ret);
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if (role == USB_ROLE_HOST) {
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ret = regulator_enable(info->vbus);
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if (ret)
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dev_err(info->dev, "enable vbus regulator failed\n");
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}
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info->last_role = role;
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dev_dbg(info->dev, "vbus regulator is %s\n",
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regulator_is_enabled(info->vbus) ? "enabled" : "disabled");
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}
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static void usb_conn_queue_dwork(struct usb_conn_info *info,
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unsigned long delay)
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{
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queue_delayed_work(system_power_efficient_wq, &info->dw_det, delay);
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}
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static irqreturn_t usb_conn_isr(int irq, void *dev_id)
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{
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struct usb_conn_info *info = dev_id;
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usb_conn_queue_dwork(info, info->debounce_jiffies);
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return IRQ_HANDLED;
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}
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static int usb_conn_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct usb_conn_info *info;
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int ret = 0;
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info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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info->dev = dev;
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info->id_gpiod = devm_gpiod_get_optional(dev, "id", GPIOD_IN);
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if (IS_ERR(info->id_gpiod))
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return PTR_ERR(info->id_gpiod);
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info->vbus_gpiod = devm_gpiod_get_optional(dev, "vbus", GPIOD_IN);
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if (IS_ERR(info->vbus_gpiod))
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return PTR_ERR(info->vbus_gpiod);
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if (!info->id_gpiod && !info->vbus_gpiod) {
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dev_err(dev, "failed to get gpios\n");
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return -ENODEV;
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}
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if (info->id_gpiod)
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ret = gpiod_set_debounce(info->id_gpiod, USB_GPIO_DEB_US);
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if (!ret && info->vbus_gpiod)
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ret = gpiod_set_debounce(info->vbus_gpiod, USB_GPIO_DEB_US);
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if (ret < 0)
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info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS);
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INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable);
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info->vbus = devm_regulator_get(dev, "vbus");
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if (IS_ERR(info->vbus)) {
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dev_err(dev, "failed to get vbus\n");
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return PTR_ERR(info->vbus);
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}
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info->role_sw = usb_role_switch_get(dev);
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if (IS_ERR(info->role_sw)) {
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if (PTR_ERR(info->role_sw) != -EPROBE_DEFER)
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dev_err(dev, "failed to get role switch\n");
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return PTR_ERR(info->role_sw);
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}
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if (info->id_gpiod) {
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info->id_irq = gpiod_to_irq(info->id_gpiod);
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if (info->id_irq < 0) {
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dev_err(dev, "failed to get ID IRQ\n");
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ret = info->id_irq;
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goto put_role_sw;
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}
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ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
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usb_conn_isr, USB_CONN_IRQF,
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pdev->name, info);
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if (ret < 0) {
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dev_err(dev, "failed to request ID IRQ\n");
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goto put_role_sw;
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}
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}
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if (info->vbus_gpiod) {
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info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
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if (info->vbus_irq < 0) {
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dev_err(dev, "failed to get VBUS IRQ\n");
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ret = info->vbus_irq;
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goto put_role_sw;
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}
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ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
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usb_conn_isr, USB_CONN_IRQF,
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pdev->name, info);
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if (ret < 0) {
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dev_err(dev, "failed to request VBUS IRQ\n");
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goto put_role_sw;
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}
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}
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platform_set_drvdata(pdev, info);
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/* Perform initial detection */
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usb_conn_queue_dwork(info, 0);
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return 0;
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put_role_sw:
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usb_role_switch_put(info->role_sw);
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return ret;
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}
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static int usb_conn_remove(struct platform_device *pdev)
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{
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struct usb_conn_info *info = platform_get_drvdata(pdev);
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cancel_delayed_work_sync(&info->dw_det);
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if (info->last_role == USB_ROLE_HOST)
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regulator_disable(info->vbus);
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usb_role_switch_put(info->role_sw);
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return 0;
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}
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static int __maybe_unused usb_conn_suspend(struct device *dev)
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{
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struct usb_conn_info *info = dev_get_drvdata(dev);
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if (info->id_gpiod)
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disable_irq(info->id_irq);
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if (info->vbus_gpiod)
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disable_irq(info->vbus_irq);
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pinctrl_pm_select_sleep_state(dev);
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return 0;
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}
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static int __maybe_unused usb_conn_resume(struct device *dev)
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{
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struct usb_conn_info *info = dev_get_drvdata(dev);
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pinctrl_pm_select_default_state(dev);
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if (info->id_gpiod)
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enable_irq(info->id_irq);
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if (info->vbus_gpiod)
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enable_irq(info->vbus_irq);
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usb_conn_queue_dwork(info, 0);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops,
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usb_conn_suspend, usb_conn_resume);
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static const struct of_device_id usb_conn_dt_match[] = {
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{ .compatible = "gpio-usb-b-connector", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, usb_conn_dt_match);
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static struct platform_driver usb_conn_driver = {
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.probe = usb_conn_probe,
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.remove = usb_conn_remove,
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.driver = {
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.name = "usb-conn-gpio",
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.pm = &usb_conn_pm_ops,
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.of_match_table = usb_conn_dt_match,
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},
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};
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module_platform_driver(usb_conn_driver);
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MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>");
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MODULE_DESCRIPTION("USB GPIO based connection detection driver");
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MODULE_LICENSE("GPL v2");
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