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From:   Silesh C V <svellattu@mvista.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-i2c@vger.kernel.org, linux-rdma@vger.kernel.org,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-spi@vger.kernel.org,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Wolfram Sang <wsa@the-dreams.de>,
        Lijun Ou <oulijun@huawei.com>,
        "Wei Hu(Xavier)" <xavier.huwei@huawei.com>,
        Yisen Zhuang <yisen.zhuang@huawei.com>,
        Salil Mehta <salil.mehta@huawei.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Silesh C V <svellattu@mvista.com>
Subject: [PATCH v3 1/2] Driver core: add bus_find_device_by_fwnode
Date:   Tue,  9 Oct 2018 15:47:24 +0530
Message-Id: <1539080245-25818-1-git-send-email-svellattu@mvista.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Some drivers need to find the device on a bus having a specific firmware
node. Currently, such drivers have their own implementations to do this.
Provide a helper similar to bus_find_device_by_name so that each driver
does not have to reinvent this.

Signed-off-by: Silesh C V <svellattu@mvista.com>
---
Changes since v2: 
	- make use of dev_fwnode in match_fwnode.

 drivers/base/bus.c     | 20 ++++++++++++++++++++
 include/linux/device.h |  3 +++
 2 files changed, 23 insertions(+)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 8bfd27e..a2f39db 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -17,6 +17,7 @@
 #include <linux/string.h>
 #include <linux/mutex.h>
 #include <linux/sysfs.h>
+#include <linux/property.h>
 #include "base.h"
 #include "power/power.h"
 
@@ -373,6 +374,25 @@ struct device *bus_find_device_by_name(struct bus_type *bus,
 }
 EXPORT_SYMBOL_GPL(bus_find_device_by_name);
 
+static int match_fwnode(struct device *dev, void *fwnode)
+{
+	return dev_fwnode(dev) == fwnode;
+}
+
+/**
+ * bus_find_device_by_fwnode - device iterator for locating a particular device
+ * having a specific firmware node
+ * @bus: bus type
+ * @start: Device to begin with
+ * @fwnode: firmware node of the device to match
+ */
+struct device *bus_find_device_by_fwnode(struct bus_type *bus, struct device *start,
+					struct fwnode_handle *fwnode)
+{
+	return bus_find_device(bus, start, (void *)fwnode, match_fwnode);
+}
+EXPORT_SYMBOL_GPL(bus_find_device_by_fwnode);
+
 /**
  * subsys_find_device_by_id - find a device with a specific enumeration number
  * @subsys: subsystem
diff --git a/include/linux/device.h b/include/linux/device.h
index 8f88254..09384f6 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -171,6 +171,9 @@ struct device *bus_find_device(struct bus_type *bus, struct device *start,
 struct device *bus_find_device_by_name(struct bus_type *bus,
 				       struct device *start,
 				       const char *name);
+struct device *bus_find_device_by_fwnode(struct bus_type *bus,
+				       struct device *start,
+				       struct fwnode_handle *fwnode);
 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,
-- 
1.9.1