diff options
author | Chunfeng Yun <chunfeng.yun@mediatek.com> | 2019-08-29 12:22:37 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-03 20:01:04 +0300 |
commit | 4602f3bff2669012c1147eecfe74c121765f5c56 (patch) | |
tree | 0b7ef76b9b00c6b95d5f003f3c454b4eb3423c24 /drivers | |
parent | 12b591bccc463307a21d925c19e7f61982902e08 (diff) | |
download | linux-4602f3bff2669012c1147eecfe74c121765f5c56.tar.xz |
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/usb/common/Kconfig | 13 | ||||
-rw-r--r-- | drivers/usb/common/Makefile | 1 | ||||
-rw-r--r-- | drivers/usb/common/usb-conn-gpio.c | 284 |
3 files changed, 298 insertions, 0 deletions
diff --git a/drivers/usb/common/Kconfig b/drivers/usb/common/Kconfig index 848545b099cf..d611477aae41 100644 --- a/drivers/usb/common/Kconfig +++ b/drivers/usb/common/Kconfig @@ -36,3 +36,16 @@ config USB_ULPI_BUS To compile this driver as a module, choose M here: the module will be called ulpi. +config USB_CONN_GPIO + tristate "USB GPIO Based Connection Detection Driver" + depends on GPIOLIB + select USB_ROLE_SWITCH + 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, and another input GPIO may be also used to detect + Vbus pin at the same time, it also can be used to enable/disable + device if an input GPIO is only used to detect Vbus pin. + + To compile the driver as a module, choose M here: the module will + be called usb-conn-gpio.ko diff --git a/drivers/usb/common/Makefile b/drivers/usb/common/Makefile index 76f3e80623db..8ac4d21ef5c8 100644 --- a/drivers/usb/common/Makefile +++ b/drivers/usb/common/Makefile @@ -8,5 +8,6 @@ usb-common-y += common.o usb-common-$(CONFIG_TRACING) += debug.o usb-common-$(CONFIG_USB_LED_TRIG) += led.o +obj-$(CONFIG_USB_CONN_GPIO) += usb-conn-gpio.o obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o obj-$(CONFIG_USB_ULPI_BUS) += ulpi.o diff --git a/drivers/usb/common/usb-conn-gpio.c b/drivers/usb/common/usb-conn-gpio.c new file mode 100644 index 000000000000..87338f9eb5be --- /dev/null +++ b/drivers/usb/common/usb-conn-gpio.c @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * USB GPIO Based Connection Detection 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/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 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(dev, "vbus"); + if (IS_ERR(info->vbus)) { + dev_err(dev, "failed to get vbus\n"); + return PTR_ERR(info->vbus); + } + + info->role_sw = usb_role_switch_get(dev); + if (IS_ERR(info->role_sw)) { + if (PTR_ERR(info->role_sw) != -EPROBE_DEFER) + 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"); + 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); + + /* Perform initial detection */ + usb_conn_queue_dwork(info, 0); + + return 0; + +put_role_sw: + usb_role_switch_put(info->role_sw); + return ret; +} + +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); + +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"); |