3 files changed, 61 insertions, 7 deletions

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index b4a71119a4b0..baf0153b7bca 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -1039,3 +1039,14 @@ void of_gpiochip_remove(struct gpio_chip *chip)
 {
 	of_node_put(chip->of_node);
 }
+
+void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev)
+{
+	/* If the gpiochip has an assigned OF node this takes precedence */
+	if (gc->of_node)
+		gdev->dev.of_node = gc->of_node;
+	else
+		gc->of_node = gdev->dev.of_node;
+	if (gdev->dev.of_node)
+		gdev->dev.fwnode = of_fwnode_handle(gdev->dev.of_node);
+}
diff --git a/drivers/gpio/gpiolib-of.h b/drivers/gpio/gpiolib-of.h
index ed26664f1537..8af2bc899aab 100644
--- a/drivers/gpio/gpiolib-of.h
+++ b/drivers/gpio/gpiolib-of.h
@@ -15,6 +15,7 @@ int of_gpiochip_add(struct gpio_chip *gc);
 void of_gpiochip_remove(struct gpio_chip *gc);
 int of_gpio_get_count(struct device *dev, const char *con_id);
 bool of_gpio_need_valid_mask(const struct gpio_chip *gc);
+void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev);
 #else
 static inline struct gpio_desc *of_find_gpio(struct device *dev,
 					     const char *con_id,
@@ -33,6 +34,10 @@ static inline bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
 {
 	return false;
 }
+static inline void of_gpio_dev_init(struct gpio_chip *gc,
+				    struct gpio_device *gdev)
+{
+}
 #endif /* CONFIG_OF_GPIO */
 
 extern struct notifier_block gpio_of_notifier;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 844198cb4e31..adf55db080d8 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -56,8 +56,10 @@
 static DEFINE_IDA(gpio_ida);
 static dev_t gpio_devt;
 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
+static int gpio_bus_match(struct device *dev, struct device_driver *drv);
 static struct bus_type gpio_bus_type = {
 	.name = "gpio",
+	.match = gpio_bus_match,
 };
 
 /*
@@ -590,13 +592,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 		gdev->dev.of_node = gc->parent->of_node;
 	}
 
-#ifdef CONFIG_OF_GPIO
-	/* If the gpiochip has an assigned OF node this takes precedence */
-	if (gc->of_node)
-		gdev->dev.of_node = gc->of_node;
-	else
-		gc->of_node = gdev->dev.of_node;
-#endif
+	of_gpio_dev_init(gc, gdev);
 
 	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
 	if (gdev->id < 0) {
@@ -4215,6 +4211,41 @@ void gpiod_put_array(struct gpio_descs *descs)
 }
 EXPORT_SYMBOL_GPL(gpiod_put_array);
 
+
+static int gpio_bus_match(struct device *dev, struct device_driver *drv)
+{
+	/*
+	 * Only match if the fwnode doesn't already have a proper struct device
+	 * created for it.
+	 */
+	if (dev->fwnode && dev->fwnode->dev != dev)
+		return 0;
+	return 1;
+}
+
+static int gpio_stub_drv_probe(struct device *dev)
+{
+	/*
+	 * The DT node of some GPIO chips have a "compatible" property, but
+	 * never have a struct device added and probed by a driver to register
+	 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
+	 * the consumers of the GPIO chip to get probe deferred forever because
+	 * they will be waiting for a device associated with the GPIO chip
+	 * firmware node to get added and bound to a driver.
+	 *
+	 * To allow these consumers to probe, we associate the struct
+	 * gpio_device of the GPIO chip with the firmware node and then simply
+	 * bind it to this stub driver.
+	 */
+	return 0;
+}
+
+static struct device_driver gpio_stub_drv = {
+	.name = "gpio_stub_drv",
+	.bus = &gpio_bus_type,
+	.probe = gpio_stub_drv_probe,
+};
+
 static int __init gpiolib_dev_init(void)
 {
 	int ret;
@@ -4226,9 +4257,16 @@ static int __init gpiolib_dev_init(void)
 		return ret;
 	}
 
+	if (driver_register(&gpio_stub_drv) < 0) {
+		pr_err("gpiolib: could not register GPIO stub driver\n");
+		bus_unregister(&gpio_bus_type);
+		return ret;
+	}
+
 	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
 	if (ret < 0) {
 		pr_err("gpiolib: failed to allocate char dev region\n");
+		driver_unregister(&gpio_stub_drv);
 		bus_unregister(&gpio_bus_type);
 		return ret;
 	}