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path: root/drivers/extcon/extcon-usb-gpio.c
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Diffstat (limited to 'drivers/extcon/extcon-usb-gpio.c')
-rw-r--r--drivers/extcon/extcon-usb-gpio.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
new file mode 100644
index 0000000000..40d967a11e
--- /dev/null
+++ b/drivers/extcon/extcon-usb-gpio.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
+ *
+ * Copyright (C) 2015 Texas Instruments Incorporated - https://www.ti.com
+ * Author: Roger Quadros <rogerq@ti.com>
+ */
+
+#include <linux/extcon-provider.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/mod_devicetable.h>
+
+#define USB_GPIO_DEBOUNCE_MS 20 /* ms */
+
+struct usb_extcon_info {
+ struct device *dev;
+ struct extcon_dev *edev;
+
+ struct gpio_desc *id_gpiod;
+ struct gpio_desc *vbus_gpiod;
+ int id_irq;
+ int vbus_irq;
+
+ unsigned long debounce_jiffies;
+ struct delayed_work wq_detcable;
+};
+
+static const unsigned int usb_extcon_cable[] = {
+ EXTCON_USB,
+ EXTCON_USB_HOST,
+ EXTCON_NONE,
+};
+
+/*
+ * "USB" = VBUS and "USB-HOST" = !ID, so we have:
+ * Both "USB" and "USB-HOST" can't be set as active at the
+ * same time so if "USB-HOST" is active (i.e. ID is 0) we keep "USB" inactive
+ * even if VBUS is on.
+ *
+ * State | ID | VBUS
+ * ----------------------------------------
+ * [1] USB | H | H
+ * [2] none | H | L
+ * [3] USB-HOST | L | H
+ * [4] USB-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_extcon_detect_cable(struct work_struct *work)
+{
+ int id, vbus;
+ struct usb_extcon_info *info = container_of(to_delayed_work(work),
+ struct usb_extcon_info,
+ wq_detcable);
+
+ /* check ID and VBUS and update cable state */
+ id = info->id_gpiod ?
+ gpiod_get_value_cansleep(info->id_gpiod) : 1;
+ vbus = info->vbus_gpiod ?
+ gpiod_get_value_cansleep(info->vbus_gpiod) : id;
+
+ /* at first we clean states which are no longer active */
+ if (id)
+ extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
+ if (!vbus)
+ extcon_set_state_sync(info->edev, EXTCON_USB, false);
+
+ if (!id) {
+ extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
+ } else {
+ if (vbus)
+ extcon_set_state_sync(info->edev, EXTCON_USB, true);
+ }
+}
+
+static irqreturn_t usb_irq_handler(int irq, void *dev_id)
+{
+ struct usb_extcon_info *info = dev_id;
+
+ queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
+ info->debounce_jiffies);
+
+ return IRQ_HANDLED;
+}
+
+static int usb_extcon_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct usb_extcon_info *info;
+ int ret;
+
+ if (!np)
+ return -EINVAL;
+
+ info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->dev = dev;
+ info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
+ info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
+ GPIOD_IN);
+
+ if (!info->id_gpiod && !info->vbus_gpiod) {
+ dev_err(dev, "failed to get gpios\n");
+ return -ENODEV;
+ }
+
+ if (IS_ERR(info->id_gpiod))
+ return PTR_ERR(info->id_gpiod);
+
+ if (IS_ERR(info->vbus_gpiod))
+ return PTR_ERR(info->vbus_gpiod);
+
+ info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
+ if (IS_ERR(info->edev)) {
+ dev_err(dev, "failed to allocate extcon device\n");
+ return -ENOMEM;
+ }
+
+ ret = devm_extcon_dev_register(dev, info->edev);
+ if (ret < 0) {
+ dev_err(dev, "failed to register extcon device\n");
+ return ret;
+ }
+
+ if (info->id_gpiod)
+ ret = gpiod_set_debounce(info->id_gpiod,
+ USB_GPIO_DEBOUNCE_MS * 1000);
+ if (!ret && info->vbus_gpiod)
+ ret = gpiod_set_debounce(info->vbus_gpiod,
+ USB_GPIO_DEBOUNCE_MS * 1000);
+
+ if (ret < 0)
+ info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);
+
+ INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);
+
+ 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_irq_handler,
+ IRQF_TRIGGER_RISING |
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ pdev->name, info);
+ if (ret < 0) {
+ dev_err(dev, "failed to request handler for 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_irq_handler,
+ IRQF_TRIGGER_RISING |
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ pdev->name, info);
+ if (ret < 0) {
+ dev_err(dev, "failed to request handler for VBUS IRQ\n");
+ return ret;
+ }
+ }
+
+ platform_set_drvdata(pdev, info);
+ device_set_wakeup_capable(&pdev->dev, true);
+
+ /* Perform initial detection */
+ usb_extcon_detect_cable(&info->wq_detcable.work);
+
+ return 0;
+}
+
+static int usb_extcon_remove(struct platform_device *pdev)
+{
+ struct usb_extcon_info *info = platform_get_drvdata(pdev);
+
+ cancel_delayed_work_sync(&info->wq_detcable);
+ device_init_wakeup(&pdev->dev, false);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int usb_extcon_suspend(struct device *dev)
+{
+ struct usb_extcon_info *info = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (device_may_wakeup(dev)) {
+ if (info->id_gpiod) {
+ ret = enable_irq_wake(info->id_irq);
+ if (ret)
+ return ret;
+ }
+ if (info->vbus_gpiod) {
+ ret = enable_irq_wake(info->vbus_irq);
+ if (ret) {
+ if (info->id_gpiod)
+ disable_irq_wake(info->id_irq);
+
+ return ret;
+ }
+ }
+ }
+
+ if (!device_may_wakeup(dev))
+ pinctrl_pm_select_sleep_state(dev);
+
+ return ret;
+}
+
+static int usb_extcon_resume(struct device *dev)
+{
+ struct usb_extcon_info *info = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (!device_may_wakeup(dev))
+ pinctrl_pm_select_default_state(dev);
+
+ if (device_may_wakeup(dev)) {
+ if (info->id_gpiod) {
+ ret = disable_irq_wake(info->id_irq);
+ if (ret)
+ return ret;
+ }
+ if (info->vbus_gpiod) {
+ ret = disable_irq_wake(info->vbus_irq);
+ if (ret) {
+ if (info->id_gpiod)
+ enable_irq_wake(info->id_irq);
+
+ return ret;
+ }
+ }
+ }
+
+ queue_delayed_work(system_power_efficient_wq,
+ &info->wq_detcable, 0);
+
+ return ret;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
+ usb_extcon_suspend, usb_extcon_resume);
+
+static const struct of_device_id usb_extcon_dt_match[] = {
+ { .compatible = "linux,extcon-usb-gpio", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
+
+static const struct platform_device_id usb_extcon_platform_ids[] = {
+ { .name = "extcon-usb-gpio", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);
+
+static struct platform_driver usb_extcon_driver = {
+ .probe = usb_extcon_probe,
+ .remove = usb_extcon_remove,
+ .driver = {
+ .name = "extcon-usb-gpio",
+ .pm = &usb_extcon_pm_ops,
+ .of_match_table = usb_extcon_dt_match,
+ },
+ .id_table = usb_extcon_platform_ids,
+};
+
+module_platform_driver(usb_extcon_driver);
+
+MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
+MODULE_DESCRIPTION("USB GPIO extcon driver");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 06:16:04 +0000