extcon: usb-gpio: Add VBUS detection support

Driver can now work with both ID and VBUS pins or either one of
them.

There can be the following 3 cases

1) Both ID and VBUS GPIOs are available:

ID = LOW -> USB_HOST active, USB inactive
ID = HIGH -> USB_HOST inactive, USB state is same as VBUS.

2) Only ID GPIO is available:

ID = LOW -> USB_HOST active, USB inactive
ID = HIGH -> USB_HOST inactive, USB active

3) Only VBUS GPIO is available:

VBUS = LOW -> USB_HOST inactive, USB inactive
VBUS = HIGH -> USB_HOST inactive, USB active

Signed-off-by: Roger Quadros <rogerq@ti.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

diff --git a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
index af0b903..dfc14f7 100644 (file)
--- a/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
+++ b/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
@@ -5,7 +5,10 @@ connected to a GPIO pin.
 
 Required properties:
 - compatible: Should be "linux,extcon-usb-gpio"
+
+Either one of id-gpio or vbus-gpio must be present. Both can be present as well.
 - id-gpio: gpio for USB ID pin. See gpio binding.
+- vbus-gpio: gpio for USB VBUS pin.
 
 Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below:
        extcon_usb1 {

diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
index a27d350..d589c5f 100644 (file)
--- a/drivers/extcon/extcon-usb-gpio.c
+++ b/drivers/extcon/extcon-usb-gpio.c
@@ -24,7 +24,6 @@
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
-#include <linux/pm_wakeirq.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/acpi.h>
@@ -36,7 +35,9 @@ struct usb_extcon_info {
        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;
@@ -48,31 +49,47 @@ static const unsigned int usb_extcon_cable[] = {
        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;
+       int id, vbus;
        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.
-                */
+       /* 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);
-               extcon_set_state_sync(info->edev, EXTCON_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.
-                */
+       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);
        }
 }
 
@@ -101,12 +118,21 @@ static int usb_extcon_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        info->dev = dev;
-       info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
-       if (IS_ERR(info->id_gpiod)) {
-               dev_err(dev, "failed to get ID GPIO\n");
-               return PTR_ERR(info->id_gpiod);
+       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");
@@ -119,32 +145,56 @@ static int usb_extcon_probe(struct platform_device *pdev)
                return ret;
        }
 
-       ret = gpiod_set_debounce(info->id_gpiod,
-                                USB_GPIO_DEBOUNCE_MS * 1000);
+       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);
 
-       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;
+       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;
+               }
        }
 
-       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_init_wakeup(dev, true);
-       dev_pm_set_wake_irq(dev, info->id_irq);
 
        /* Perform initial detection */
        usb_extcon_detect_cable(&info->wq_detcable.work);
@@ -157,8 +207,6 @@ 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);
-
-       dev_pm_clear_wake_irq(&pdev->dev);
        device_init_wakeup(&pdev->dev, false);
 
        return 0;
@@ -170,12 +218,32 @@ 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;
+                       }
+               }
+       }
+
        /*
         * 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);
+       if (info->id_gpiod)
+               disable_irq(info->id_irq);
+       if (info->vbus_gpiod)
+               disable_irq(info->vbus_irq);
 
        return ret;
 }
@@ -185,7 +253,28 @@ static int usb_extcon_resume(struct device *dev)
        struct usb_extcon_info *info = dev_get_drvdata(dev);
        int ret = 0;
 
-       enable_irq(info->id_irq);
+       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;
+                       }
+               }
+       }
+
+       if (info->id_gpiod)
+               enable_irq(info->id_irq);
+       if (info->vbus_gpiod)
+               enable_irq(info->vbus_irq);
+
        if (!device_may_wakeup(dev))
                queue_delayed_work(system_power_efficient_wq,
                                   &info->wq_detcable, 0);