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-rw-r--r--drivers/extcon/Kconfig7
-rw-r--r--drivers/extcon/Makefile1
-rw-r--r--drivers/extcon/extcon-usb-gpio.c237
3 files changed, 245 insertions, 0 deletions
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 6a1f7de6fa54..e4c01ab046f7 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -93,4 +93,11 @@ config EXTCON_SM5502
Silicon Mitus SM5502. The SM5502 is a USB port accessory
detector and switch.
+config EXTCON_USB_GPIO
+ tristate "USB GPIO extcon support"
+ depends on GPIOLIB
+ help
+ Say Y here to enable GPIO based USB cable detection extcon support.
+ Used typically if GPIO is used for USB ID pin detection.
+
endif # MULTISTATE_SWITCH
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 0370b42e5a27..6a08a98dc069 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o
obj-$(CONFIG_EXTCON_PALMAS) += extcon-palmas.o
obj-$(CONFIG_EXTCON_RT8973A) += extcon-rt8973a.o
obj-$(CONFIG_EXTCON_SM5502) += extcon-sm5502.o
+obj-$(CONFIG_EXTCON_USB_GPIO) += extcon-usb-gpio.o
diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
new file mode 100644
index 000000000000..3f0bad3ce8aa
--- /dev/null
+++ b/drivers/extcon/extcon-usb-gpio.c
@@ -0,0 +1,237 @@
+/**
+ * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
+ *
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Roger Quadros <rogerq@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/extcon.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define USB_GPIO_DEBOUNCE_MS 20 /* ms */
+
+struct usb_extcon_info {
+ struct device *dev;
+ struct extcon_dev *edev;
+
+ struct gpio_desc *id_gpiod;
+ int id_irq;
+
+ unsigned long debounce_jiffies;
+ struct delayed_work wq_detcable;
+};
+
+/* List of detectable cables */
+enum {
+ EXTCON_CABLE_USB = 0,
+ EXTCON_CABLE_USB_HOST,
+
+ EXTCON_CABLE_END,
+};
+
+static const char *usb_extcon_cable[] = {
+ [EXTCON_CABLE_USB] = "USB",
+ [EXTCON_CABLE_USB_HOST] = "USB-HOST",
+ NULL,
+};
+
+static void usb_extcon_detect_cable(struct work_struct *work)
+{
+ int id;
+ struct usb_extcon_info *info = container_of(to_delayed_work(work),
+ struct usb_extcon_info,
+ wq_detcable);
+
+ /* check ID and update cable state */
+ id = gpiod_get_value_cansleep(info->id_gpiod);
+ if (id) {
+ /*
+ * ID = 1 means USB HOST cable detached.
+ * As we don't have event for USB peripheral cable attached,
+ * we simulate USB peripheral attach here.
+ */
+ extcon_set_cable_state(info->edev,
+ usb_extcon_cable[EXTCON_CABLE_USB_HOST],
+ false);
+ extcon_set_cable_state(info->edev,
+ usb_extcon_cable[EXTCON_CABLE_USB],
+ true);
+ } else {
+ /*
+ * ID = 0 means USB HOST cable attached.
+ * As we don't have event for USB peripheral cable detached,
+ * we simulate USB peripheral detach here.
+ */
+ extcon_set_cable_state(info->edev,
+ usb_extcon_cable[EXTCON_CABLE_USB],
+ false);
+ extcon_set_cable_state(info->edev,
+ usb_extcon_cable[EXTCON_CABLE_USB_HOST],
+ 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(&pdev->dev, "id");
+ if (IS_ERR(info->id_gpiod)) {
+ dev_err(dev, "failed to get ID GPIO\n");
+ return PTR_ERR(info->id_gpiod);
+ }
+
+ ret = gpiod_set_debounce(info->id_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);
+
+ 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;
+ }
+
+ 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;
+ }
+
+ platform_set_drvdata(pdev, info);
+ device_init_wakeup(dev, 1);
+
+ /* 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);
+
+ 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)) {
+ ret = enable_irq_wake(info->id_irq);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * We don't want to process any IRQs after this point
+ * as GPIOs used behind I2C subsystem might not be
+ * accessible until resume completes. So disable IRQ.
+ */
+ disable_irq(info->id_irq);
+
+ 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)) {
+ ret = disable_irq_wake(info->id_irq);
+ if (ret)
+ return ret;
+ }
+
+ enable_irq(info->id_irq);
+
+ return ret;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
+ usb_extcon_suspend, usb_extcon_resume);
+
+static struct of_device_id usb_extcon_dt_match[] = {
+ { .compatible = "linux,extcon-usb-gpio", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);
+
+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,
+ },
+};
+
+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 2.25.1) at 2024-12-03 17:44:11 +0000