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From: Robert Baldyga <r.baldyga@samsung.com>
To: cw00.choi@samsung.com
Cc: myungjoo.ham@samsung.com, rogerq@ti.com,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	m.szyprowski@samsung.com, Robert Baldyga <r.baldyga@samsung.com>
Subject: [PATCH 2/4] extcon: usb-gpio: add support for VBUS detection
Date: Tue, 31 Mar 2015 09:46:01 +0200	[thread overview]
Message-ID: <1427787963-23562-3-git-send-email-r.baldyga@samsung.com> (raw)
In-Reply-To: <1427787963-23562-1-git-send-email-r.baldyga@samsung.com>

This patch adds VBUS pin detection support to extcon-usb-gpio driver.
It allows to use this driver with boards which have both VBUS and ID
pins, or only one of them.

Following table of states presents relationship between this signals
and detected cable type:

 State        |    ID   |   VBUS
----------------------------------
 [1] USB      |    H    |    H
 [2] disconn. |    H    |    L
 [3] USB-HOST |    L    |    H
 [4] USB-HOST |    L    |    L

In case we have only one of these signals:
- ID pin only: we can distinguish between states [1] and [3].
- VBUS pin only: we can distinguish between states [1] and [2].

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
---
 drivers/extcon/extcon-usb-gpio.c | 159 +++++++++++++++++++++++++++++----------
 1 file changed, 118 insertions(+), 41 deletions(-)

diff --git a/drivers/extcon/extcon-usb-gpio.c b/drivers/extcon/extcon-usb-gpio.c
index f6aa99d..02ff40e 100644
--- a/drivers/extcon/extcon-usb-gpio.c
+++ b/drivers/extcon/extcon-usb-gpio.c
@@ -32,7 +32,9 @@ 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;
@@ -52,21 +54,50 @@ static const char *usb_extcon_cable[] = {
 	NULL,
 };
 
+/*
+ *  State        |    ID   |   VBUS
+ * ----------------------------------
+ *  [1] USB      |    H    |    H
+ *  [2] disconn. |    H    |    L
+ *  [3] USB-HOST |    L    |    H
+ *  [4] USB-HOST |    L    |    L
+ *
+ */
+
 static void usb_extcon_detect_cable(struct work_struct *work)
 {
 	int id;
+	int 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 */
+
+	/*
+	 * If we don't have id pin, we want to detect states [1] and [2],
+	 * so we set id to value 1.
+	 */
+	id = info->id_gpiod ?
+		gpiod_get_value_cansleep(info->id_gpiod) : 1;
+
+	/*
+	 * If we don't have vbus pin, we want to detect states [1] and [3],
+	 * so we set vbus to value 1.
+	 */
+	vbus = info->vbus_gpiod ?
+		gpiod_get_value_cansleep(info->vbus_gpiod) : 1;
+
+	if (id == 0) {
+		/* ID = 0 means USB HOST cable attached. */
+		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);
+	} else if (vbus) {
+		/* ID = 1 and VBUS = 1 means USB cable attached. */
 		extcon_set_cable_state(info->edev,
 				       usb_extcon_cable[EXTCON_CABLE_USB_HOST],
 				       false);
@@ -74,17 +105,13 @@ static void usb_extcon_detect_cable(struct work_struct *work)
 				       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.
-		 */
+		/* ID = 1 and VBUS = 0 means USB cable detached. */
 		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);
+				       false);
 	}
 }
 
@@ -113,10 +140,12 @@ static int usb_extcon_probe(struct platform_device *pdev)
 		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);
+	info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id");
+	info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus");
+
+	if (!info->id_gpiod && !info->vbus_gpiod) {
+		dev_err(dev, "failed to get gpios\n");
+		return -ENODEV;
 	}
 
 	info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
@@ -131,27 +160,51 @@ 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->id_gpiod)
+			gpiod_set_debounce(info->vbus_gpiod, 0);
+	}
 	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);
@@ -179,9 +232,18 @@ static int usb_extcon_suspend(struct device *dev)
 	int ret = 0;
 
 	if (device_may_wakeup(dev)) {
-		ret = enable_irq_wake(info->id_irq);
-		if (ret)
-			return ret;
+		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) {
+				disable_irq_wake(info->id_irq);
+				return ret;
+			}
+		}
 	}
 
 	/*
@@ -189,7 +251,10 @@ static int usb_extcon_suspend(struct device *dev)
 	 * 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;
 }
@@ -200,12 +265,24 @@ static int usb_extcon_resume(struct device *dev)
 	int ret = 0;
 
 	if (device_may_wakeup(dev)) {
-		ret = disable_irq_wake(info->id_irq);
-		if (ret)
-			return ret;
+		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) {
+				enable_irq_wake(info->id_irq);
+				return ret;
+			}
+		}
 	}
 
-	enable_irq(info->id_irq);
+	if (info->id_gpiod)
+		enable_irq(info->id_irq);
+	if (info->vbus_gpiod)
+		enable_irq(info->vbus_irq);
 
 	return ret;
 }
-- 
1.9.1


  parent reply	other threads:[~2015-03-31  7:47 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-31  7:45 [PATCH 0/4] extcon: usb-gpio: fixes and improvements Robert Baldyga
2015-03-31  7:46 ` [PATCH 1/4] extcon: usb-gpio: register extcon device before IRQ registration Robert Baldyga
2015-03-31  8:37   ` Roger Quadros
2015-03-31  7:46 ` Robert Baldyga [this message]
2015-03-31  9:22   ` [PATCH 2/4] extcon: usb-gpio: add support for VBUS detection Roger Quadros
2015-03-31  7:46 ` [PATCH 3/4] extcon: usb-gpio: make debounce value configurable in devicetree Robert Baldyga
2015-03-31  9:30   ` Roger Quadros
2015-03-31 12:16     ` Robert Baldyga
2015-03-31  7:46 ` [PATCH 4/4] Documentation: extcon: usb-gpio: update usb-gpio binding description Robert Baldyga
2015-03-31 10:20   ` Roger Quadros
2015-03-31 12:04     ` Robert Baldyga

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