extcon: palmas: Add the support for VBUS detection by using GPIO

This patch support for VBUS detection by using GPIO pin.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>

drivers/extcon/extcon-palmas.c

@@ -216,11 +216,23 @@ static int palmas_usb_probe(struct platform_device *pdev)
 		return PTR_ERR(palmas_usb->id_gpiod);
 	}
 
+	palmas_usb->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
+							GPIOD_IN);
+	if (IS_ERR(palmas_usb->vbus_gpiod)) {
+		dev_err(&pdev->dev, "failed to get vbus gpio\n");
+		return PTR_ERR(palmas_usb->vbus_gpiod);
+	}
+
 	if (palmas_usb->enable_id_detection && palmas_usb->id_gpiod) {
 		palmas_usb->enable_id_detection = false;
 		palmas_usb->enable_gpio_id_detection = true;
 	}
 
+	if (palmas_usb->enable_vbus_detection && palmas_usb->vbus_gpiod) {
+		palmas_usb->enable_vbus_detection = false;
+		palmas_usb->enable_gpio_vbus_detection = true;
+	}
+
 	if (palmas_usb->enable_gpio_id_detection) {
 		u32 debounce;
 
@@ -311,6 +323,40 @@ static int palmas_usb_probe(struct platform_device *pdev)
 					palmas_usb->vbus_irq, status);
 			return status;
 		}
+	} else if (palmas_usb->enable_gpio_vbus_detection) {
+		/* remux GPIO_1 as VBUSDET */
+		status = palmas_update_bits(palmas,
+			PALMAS_PU_PD_OD_BASE,
+			PALMAS_PRIMARY_SECONDARY_PAD1,
+			PALMAS_PRIMARY_SECONDARY_PAD1_GPIO_1_MASK,
+			(1 << PALMAS_PRIMARY_SECONDARY_PAD1_GPIO_1_SHIFT));
+		if (status < 0) {
+			dev_err(&pdev->dev, "can't remux GPIO1\n");
+			return status;
+		}
+
+		palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+						       PALMAS_VBUS_OTG_IRQ);
+		palmas_usb->gpio_vbus_irq = gpiod_to_irq(palmas_usb->vbus_gpiod);
+		if (palmas_usb->gpio_vbus_irq < 0) {
+			dev_err(&pdev->dev, "failed to get vbus irq\n");
+			return palmas_usb->gpio_vbus_irq;
+		}
+		status = devm_request_threaded_irq(&pdev->dev,
+						palmas_usb->gpio_vbus_irq,
+						NULL,
+						palmas_vbus_irq_handler,
+						IRQF_TRIGGER_FALLING |
+						IRQF_TRIGGER_RISING |
+						IRQF_ONESHOT |
+						IRQF_EARLY_RESUME,
+						"palmas_usb_vbus",
+						palmas_usb);
+		if (status < 0) {
+			dev_err(&pdev->dev,
+				"failed to request handler for vbus irq\n");
+			return status;
+		}
 	}
 
 	palmas_enable_irq(palmas_usb);
@@ -337,6 +383,8 @@ static int palmas_usb_suspend(struct device *dev)
 	if (device_may_wakeup(dev)) {
 		if (palmas_usb->enable_vbus_detection)
 			enable_irq_wake(palmas_usb->vbus_irq);
+		if (palmas_usb->enable_gpio_vbus_detection)
+			enable_irq_wake(palmas_usb->gpio_vbus_irq);
 		if (palmas_usb->enable_id_detection)
 			enable_irq_wake(palmas_usb->id_irq);
 		if (palmas_usb->enable_gpio_id_detection)
@@ -352,6 +400,8 @@ static int palmas_usb_resume(struct device *dev)
 	if (device_may_wakeup(dev)) {
 		if (palmas_usb->enable_vbus_detection)
 			disable_irq_wake(palmas_usb->vbus_irq);
+		if (palmas_usb->enable_gpio_vbus_detection)
+			disable_irq_wake(palmas_usb->gpio_vbus_irq);
 		if (palmas_usb->enable_id_detection)
 			disable_irq_wake(palmas_usb->id_irq);
 		if (palmas_usb->enable_gpio_id_detection)

include/linux/mfd/palmas.h

@@ -580,7 +580,9 @@ struct palmas_usb {
 	int vbus_irq;
 
 	int gpio_id_irq;
+	int gpio_vbus_irq;
 	struct gpio_desc *id_gpiod;
+	struct gpio_desc *vbus_gpiod;
 	unsigned long sw_debounce_jiffies;
 	struct delayed_work wq_detectid;
 
@@ -589,6 +591,7 @@ struct palmas_usb {
 	bool enable_vbus_detection;
 	bool enable_id_detection;
 	bool enable_gpio_id_detection;
+	bool enable_gpio_vbus_detection;
 };
 
 #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)