drivers: Introduce device lookup variants by of_node

Introduce wrappers for {bus/driver/class}_find_device() to
locate devices by its of_node.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: devicetree@vger.kernel.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-i2c@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-spi@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Alan Tull <atull@kernel.org>
Cc: linux-fpga@vger.kernel.org
Cc: Peter Rosin <peda@axentia.se>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C part
Acked-by: Moritz Fischer <mdf@kernel.org> # For FPGA part
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20190723221838.12024-3-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/device.h

@@ -186,6 +186,18 @@ static inline struct device *bus_find_device_by_name(struct bus_type *bus,
 	return bus_find_device(bus, start, name, device_match_name);
 }
 
+/**
+ * bus_find_device_by_of_node : device iterator for locating a particular device
+ * matching the of_node.
+ * @bus: bus type
+ * @np: of_node of the device to match.
+ */
+static inline struct device *
+bus_find_device_by_of_node(struct bus_type *bus, const struct device_node *np)
+{
+	return bus_find_device(bus, NULL, np, device_match_of_node);
+}
+
 struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
 					struct device *hint);
 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
@@ -366,6 +378,19 @@ static inline struct device *driver_find_device_by_name(struct device_driver *dr
 	return driver_find_device(drv, NULL, name, device_match_name);
 }
 
+/**
+ * driver_find_device_by_of_node- device iterator for locating a particular device
+ * by of_node pointer.
+ * @driver: the driver we're iterating
+ * @np: of_node pointer to match.
+ */
+static inline struct device *
+driver_find_device_by_of_node(struct device_driver *drv,
+			      const struct device_node *np)
+{
+	return driver_find_device(drv, NULL, np, device_match_of_node);
+}
+
 void driver_deferred_probe_add(struct device *dev);
 int driver_deferred_probe_check_state(struct device *dev);
 int driver_deferred_probe_check_state_continue(struct device *dev);
@@ -507,6 +532,18 @@ static inline struct device *class_find_device_by_name(struct class *class,
 	return class_find_device(class, NULL, name, device_match_name);
 }
 
+/**
+ * class_find_device_by_of_node : device iterator for locating a particular device
+ * matching the of_node.
+ * @class: class type
+ * @np: of_node of the device to match.
+ */
+static inline struct device *
+class_find_device_by_of_node(struct class *class, const struct device_node *np)
+{
+	return class_find_device(class, NULL, np, device_match_of_node);
+}
+
 struct class_attribute {
 	struct attribute attr;
 	ssize_t (*show)(struct class *class, struct class_attribute *attr,