[PATCH v3 1/7] drivers: Introduce device lookup variants by name

[PATCH v3 1/7] drivers: Introduce device lookup variants by name

[Suzuki K Poulose]

Add a helper to match the device name for device lookup. Also
reuse this generic exported helper for the existing bus_find_device_by_name().
and add similar variants for driver/class.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Murphy <dmurphy@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: linux-leds@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-wpan@vger.kernel.org
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Stefan Schmidt <stefan@datenfreihafen.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/base/bus.c               | 24 ------------------
 drivers/base/core.c              |  6 +++++
 drivers/hwtracing/stm/core.c     |  9 +------
 drivers/leds/led-class.c         |  9 +------
 drivers/rtc/interface.c          | 11 +--------
 drivers/s390/cio/ccwgroup.c      | 10 +-------
 drivers/s390/cio/device.c        | 15 +-----------
 drivers/s390/crypto/zcrypt_api.c | 11 +--------
 drivers/usb/roles/class.c        |  8 +-----
 drivers/usb/typec/class.c        |  8 +-----
 include/linux/device.h           | 42 +++++++++++++++++++++++++++++---
 net/ieee802154/core.c            |  7 +-----
 12 files changed, 54 insertions(+), 106 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index df3cac739813..a1d1e8256324 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -342,30 +342,6 @@ struct device *bus_find_device(struct bus_type *bus,
 }
 EXPORT_SYMBOL_GPL(bus_find_device);
 
-static int match_name(struct device *dev, const void *data)
-{
-	const char *name = data;
-
-	return sysfs_streq(name, dev_name(dev));
-}
-
-/**
- * bus_find_device_by_name - device iterator for locating a particular device of a specific name
- * @bus: bus type
- * @start: Device to begin with
- * @name: name of the device to match
- *
- * This is similar to the bus_find_device() function above, but it handles
- * searching by a name automatically, no need to write another strcmp matching
- * function.
- */
-struct device *bus_find_device_by_name(struct bus_type *bus,
-				       struct device *start, const char *name)
-{
-	return bus_find_device(bus, start, (void *)name, match_name);
-}
-EXPORT_SYMBOL_GPL(bus_find_device_by_name);
-
 /**
  * subsys_find_device_by_id - find a device with a specific enumeration number
  * @subsys: subsystem
diff --git a/drivers/base/core.c b/drivers/base/core.c
index da84a73f2ba6..fb83647d685a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3357,6 +3357,12 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
 }
 EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
 
+int device_match_name(struct device *dev, const void *name)
+{
+	return sysfs_streq(dev_name(dev), name);
+}
+EXPORT_SYMBOL_GPL(device_match_name);
+
 int device_match_of_node(struct device *dev, const void *np)
 {
 	return dev->of_node == np;
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index e55b902560de..2b6bd42632e8 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -89,13 +89,6 @@ static struct class stm_class = {
 	.dev_groups	= stm_groups,
 };
 
-static int stm_dev_match(struct device *dev, const void *data)
-{
-	const char *name = data;
-
-	return sysfs_streq(name, dev_name(dev));
-}
-
 /**
  * stm_find_device() - find stm device by name
  * @buf:	character buffer containing the name
@@ -116,7 +109,7 @@ struct stm_device *stm_find_device(const char *buf)
 	if (!stm_core_up)
 		return NULL;
 
-	dev = class_find_device(&stm_class, NULL, buf, stm_dev_match);
+	dev = class_find_device_by_name(&stm_class, buf);
 	if (!dev)
 		return NULL;
 
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 4793e77808e2..d54c8e4d8954 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -213,13 +213,6 @@ static int led_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
 
-static int match_name(struct device *dev, const void *data)
-{
-	if (!dev_name(dev))
-		return 0;
-	return !strcmp(dev_name(dev), (char *)data);
-}
-
 static int led_classdev_next_name(const char *init_name, char *name,
 				  size_t len)
 {
@@ -230,7 +223,7 @@ static int led_classdev_next_name(const char *init_name, char *name,
 	strlcpy(name, init_name, len);
 
 	while ((ret < len) &&
-	       (dev = class_find_device(leds_class, NULL, name, match_name))) {
+	       (dev = class_find_device_by_name(leds_class, name))) {
 		put_device(dev);
 		ret = snprintf(name, len, "%s_%u", init_name, ++i);
 	}
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 72b7ddc43116..c93ef33b01d3 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -663,21 +663,12 @@ void rtc_update_irq(struct rtc_device *rtc,
 }
 EXPORT_SYMBOL_GPL(rtc_update_irq);
 
-static int __rtc_match(struct device *dev, const void *data)
-{
-	const char *name = data;
-
-	if (strcmp(dev_name(dev), name) == 0)
-		return 1;
-	return 0;
-}
-
 struct rtc_device *rtc_class_open(const char *name)
 {
 	struct device *dev;
 	struct rtc_device *rtc = NULL;
 
-	dev = class_find_device(rtc_class, NULL, name, __rtc_match);
+	dev = class_find_device_by_name(rtc_class, name);
 	if (dev)
 		rtc = to_rtc_device(dev);
 
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index c522e9313c50..d843e362c167 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -608,13 +608,6 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
 }
 EXPORT_SYMBOL(ccwgroup_driver_unregister);
 
-static int __ccwgroupdev_check_busid(struct device *dev, const void *id)
-{
-	const char *bus_id = id;
-
-	return (strcmp(bus_id, dev_name(dev)) == 0);
-}
-
 /**
  * get_ccwgroupdev_by_busid() - obtain device from a bus id
  * @gdrv: driver the device is owned by
@@ -631,8 +624,7 @@ struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
 {
 	struct device *dev;
 
-	dev = driver_find_device(&gdrv->driver, NULL, bus_id,
-				 __ccwgroupdev_check_busid);
+	dev = driver_find_device_by_name(&gdrv->driver, bus_id);
 
 	return dev ? to_ccwgroupdev(dev) : NULL;
 }
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index c421899be20f..131430bd48d9 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1695,18 +1695,6 @@ int ccw_device_force_console(struct ccw_device *cdev)
 EXPORT_SYMBOL_GPL(ccw_device_force_console);
 #endif
 
-/*
- * get ccw_device matching the busid, but only if owned by cdrv
- */
-static int
-__ccwdev_check_busid(struct device *dev, const void *id)
-{
-	const char *bus_id = id;
-
-	return (strcmp(bus_id, dev_name(dev)) == 0);
-}
-
-
 /**
  * get_ccwdev_by_busid() - obtain device from a bus id
  * @cdrv: driver the device is owned by
@@ -1723,8 +1711,7 @@ struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
 {
 	struct device *dev;
 
-	dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
-				 __ccwdev_check_busid);
+	dev = driver_find_device_by_name(&cdrv->driver, bus_id);
 
 	return dev ? to_ccwdev(dev) : NULL;
 }
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 1058b4b5cc1e..38a5a47b8c9c 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -133,12 +133,6 @@ struct zcdn_device {
 static int zcdn_create(const char *name);
 static int zcdn_destroy(const char *name);
 
-/* helper function, matches the name for find_zcdndev_by_name() */
-static int __match_zcdn_name(struct device *dev, const void *data)
-{
-	return strcmp(dev_name(dev), (const char *)data) == 0;
-}
-
 /* helper function, matches the devt value for find_zcdndev_by_devt() */
 static int __match_zcdn_devt(struct device *dev, const void *data)
 {
@@ -152,10 +146,7 @@ static int __match_zcdn_devt(struct device *dev, const void *data)
  */
 static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
 {
-	struct device *dev =
-		class_find_device(zcrypt_class, NULL,
-				  (void *) name,
-				  __match_zcdn_name);
+	struct device *dev = class_find_device_by_name(zcrypt_class, name);
 
 	return dev ? to_zcdn_dev(dev) : NULL;
 }
diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index 86defca6623e..c8efe60e2465 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -90,11 +90,6 @@ static int switch_fwnode_match(struct device *dev, const void *fwnode)
 	return dev_fwnode(dev) == fwnode;
 }
 
-static int switch_name_match(struct device *dev, const void *name)
-{
-	return !strcmp((const char *)name, dev_name(dev));
-}
-
 static void *usb_role_switch_match(struct device_connection *con, int ep,
 				   void *data)
 {
@@ -107,8 +102,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
 		dev = class_find_device(role_class, NULL, con->fwnode,
 					switch_fwnode_match);
 	} else {
-		dev = class_find_device(role_class, NULL, con->endpoint[ep],
-					switch_name_match);
+		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
 	}
 
 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index a18285a990a8..9b0d15b487e5 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -210,11 +210,6 @@ static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
 	return dev_fwnode(dev) == fwnode;
 }
 
-static int typec_port_name_match(struct device *dev, const void *name)
-{
-	return !strcmp((const char *)name, dev_name(dev));
-}
-
 static void *typec_port_match(struct device_connection *con, int ep, void *data)
 {
 	struct device *dev;
@@ -227,8 +222,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
 		return class_find_device(typec_class, NULL, con->fwnode,
 					 typec_port_fwnode_match);
 
-	dev = class_find_device(typec_class, NULL, con->endpoint[ep],
-				typec_port_name_match);
+	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
 
 	return dev ? dev : ERR_PTR(-EPROBE_DEFER);
 }
diff --git a/include/linux/device.h b/include/linux/device.h
index c330b75c6c57..3ba376b8b456 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -164,6 +164,7 @@ void subsys_dev_iter_init(struct subsys_dev_iter *iter,
 struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
 void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
 
+int device_match_name(struct device *dev, const void *name);
 int device_match_of_node(struct device *dev, const void *np);
 
 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
@@ -171,9 +172,20 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
 struct device *bus_find_device(struct bus_type *bus, struct device *start,
 			       const void *data,
 			       int (*match)(struct device *dev, const void *data));
-struct device *bus_find_device_by_name(struct bus_type *bus,
-				       struct device *start,
-				       const char *name);
+/**
+ * bus_find_device_by_name - device iterator for locating a particular device
+ * of a specific name.
+ * @bus: bus type
+ * @start: Device to begin with
+ * @name: name of the device to match
+ */
+static inline struct device *bus_find_device_by_name(struct bus_type *bus,
+						     struct device *start,
+						     const char *name)
+{
+	return bus_find_device(bus, start, name, device_match_name);
+}
+
 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,
@@ -342,6 +354,18 @@ struct device *driver_find_device(struct device_driver *drv,
 				  struct device *start, const void *data,
 				  int (*match)(struct device *dev, const void *data));
 
+/**
+ * driver_find_device_by_name - device iterator for locating a particular device
+ * of a specific name.
+ * @driver: the driver we're iterating
+ * @name: name of the device to match
+ */
+static inline struct device *driver_find_device_by_name(struct device_driver *drv,
+							const char *name)
+{
+	return driver_find_device(drv, NULL, name, device_match_name);
+}
+
 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);
@@ -471,6 +495,18 @@ extern struct device *class_find_device(struct class *class,
 					struct device *start, const void *data,
 					int (*match)(struct device *, const void *));
 
+/**
+ * class_find_device_by_name - device iterator for locating a particular device
+ * of a specific name.
+ * @class: class type
+ * @name: name of the device to match
+ */
+static inline struct device *class_find_device_by_name(struct class *class,
+						       const char *name)
+{
+	return class_find_device(class, NULL, name, device_match_name);
+}
+
 struct class_attribute {
 	struct attribute attr;
 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
index 60b7ac56a1f5..de259b5170ab 100644
--- a/net/ieee802154/core.c
+++ b/net/ieee802154/core.c
@@ -23,11 +23,6 @@
 LIST_HEAD(cfg802154_rdev_list);
 int cfg802154_rdev_list_generation;
 
-static int wpan_phy_match(struct device *dev, const void *data)
-{
-	return !strcmp(dev_name(dev), (const char *)data);
-}
-
 struct wpan_phy *wpan_phy_find(const char *str)
 {
 	struct device *dev;
@@ -35,7 +30,7 @@ struct wpan_phy *wpan_phy_find(const char *str)
 	if (WARN_ON(!str))
 		return NULL;
 
-	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
+	dev = class_find_device_by_name(&wpan_phy_class, str);
 	if (!dev)
 		return NULL;
 
-- 
2.21.0

[PATCH v3 3/7] drivers: Introduce device lookup variants by fwnode

[Suzuki K Poulose]

Add a helper to match the firmware node handle of a device and provide
wrappers for {bus/class/driver}_find_device() APIs to avoid proliferation
of duplicate custom match functions.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-usb@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/base/core.c                           |  6 +++
 drivers/base/devcon.c                         |  8 +---
 .../hwtracing/coresight/coresight-platform.c  | 11 +-----
 drivers/hwtracing/coresight/coresight-priv.h  |  2 -
 drivers/hwtracing/coresight/coresight.c       |  4 +-
 drivers/infiniband/hw/hns/hns_roce_hw_v1.c    |  8 +---
 drivers/iommu/arm-smmu-v3.c                   |  9 +----
 drivers/iommu/arm-smmu.c                      |  9 +----
 .../ethernet/hisilicon/hns/hns_dsaf_misc.c    |  8 +---
 drivers/usb/roles/class.c                     |  8 +---
 drivers/usb/typec/class.c                     |  8 +---
 include/linux/device.h                        | 39 +++++++++++++++++++
 12 files changed, 57 insertions(+), 63 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index fb83647d685a..e8f81a667545 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3368,3 +3368,9 @@ int device_match_of_node(struct device *dev, const void *np)
 	return dev->of_node == np;
 }
 EXPORT_SYMBOL_GPL(device_match_of_node);
+
+int device_match_fwnode(struct device *dev, const void *fwnode)
+{
+	return dev_fwnode(dev) == fwnode;
+}
+EXPORT_SYMBOL_GPL(device_match_fwnode);
diff --git a/drivers/base/devcon.c b/drivers/base/devcon.c
index 09f28479b243..1d488dc5dd0c 100644
--- a/drivers/base/devcon.c
+++ b/drivers/base/devcon.c
@@ -133,19 +133,13 @@ static struct bus_type *generic_match_buses[] = {
 	NULL,
 };
 
-static int device_fwnode_match(struct device *dev, const void *fwnode)
-{
-	return dev_fwnode(dev) == fwnode;
-}
-
 static void *device_connection_fwnode_match(struct device_connection *con)
 {
 	struct bus_type *bus;
 	struct device *dev;
 
 	for (bus = generic_match_buses[0]; bus; bus++) {
-		dev = bus_find_device(bus, NULL, (void *)con->fwnode,
-				      device_fwnode_match);
+		dev = bus_find_device_by_fwnode(bus, con->fwnode);
 		if (dev && !strncmp(dev_name(dev), con->id, strlen(con->id)))
 			return dev;
 
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index dad7d96c5943..3c5bee429105 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -37,11 +37,6 @@ static int coresight_alloc_conns(struct device *dev,
 	return 0;
 }
 
-int coresight_device_fwnode_match(struct device *dev, const void *fwnode)
-{
-	return dev_fwnode(dev) == fwnode;
-}
-
 static struct device *
 coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
 {
@@ -51,8 +46,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
 	 * If we have a non-configurable replicator, it will be found on the
 	 * platform bus.
 	 */
-	dev = bus_find_device(&platform_bus_type, NULL,
-			      fwnode, coresight_device_fwnode_match);
+	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
 	if (dev)
 		return dev;
 
@@ -60,8 +54,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
 	 * We have a configurable component - circle through the AMBA bus
 	 * looking for the device that matches the endpoint node.
 	 */
-	return bus_find_device(&amba_bustype, NULL,
-			       fwnode, coresight_device_fwnode_match);
+	return bus_find_device_by_fwnode(&amba_bustype, fwnode);
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 7d401790dd7e..61d7f9ff054d 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -202,6 +202,4 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
 
 void coresight_release_platform_data(struct coresight_platform_data *pdata);
 
-int coresight_device_fwnode_match(struct device *dev, const void *fwnode);
-
 #endif
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 55db77f6410b..6453c67a4d01 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -1046,9 +1046,7 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)
 		struct coresight_connection *conn = &csdev->pdata->conns[i];
 		struct device *dev = NULL;
 
-		dev = bus_find_device(&coresight_bustype, NULL,
-				      (void *)conn->child_fwnode,
-				      coresight_device_fwnode_match);
+		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
 		if (dev) {
 			conn->child_dev = to_coresight_device(dev);
 			/* and put reference from 'bus_find_device()' */
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
index 81e6dedb1e02..fa05e943038a 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
@@ -4499,19 +4499,13 @@ static const struct acpi_device_id hns_roce_acpi_match[] = {
 };
 MODULE_DEVICE_TABLE(acpi, hns_roce_acpi_match);
 
-static int hns_roce_node_match(struct device *dev, const void *fwnode)
-{
-	return dev->fwnode == fwnode;
-}
-
 static struct
 platform_device *hns_roce_find_pdev(struct fwnode_handle *fwnode)
 {
 	struct device *dev;
 
 	/* get the 'device' corresponding to the matching 'fwnode' */
-	dev = bus_find_device(&platform_bus_type, NULL,
-			      fwnode, hns_roce_node_match);
+	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
 	/* get the platform device */
 	return dev ? to_platform_device(dev) : NULL;
 }
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index a9a9fabd3968..6f0e13fa5e1a 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2034,16 +2034,11 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
 
 static struct platform_driver arm_smmu_driver;
 
-static int arm_smmu_match_node(struct device *dev, const void *data)
-{
-	return dev->fwnode == data;
-}
-
 static
 struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
 {
-	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
-						fwnode, arm_smmu_match_node);
+	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
+							  fwnode);
 	put_device(dev);
 	return dev ? dev_get_drvdata(dev) : NULL;
 }
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 64977c131ee6..aa06498f291d 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1426,16 +1426,11 @@ static bool arm_smmu_capable(enum iommu_cap cap)
 	}
 }
 
-static int arm_smmu_match_node(struct device *dev, const void *data)
-{
-	return dev->fwnode == data;
-}
-
 static
 struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
 {
-	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
-						fwnode, arm_smmu_match_node);
+	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
+							  fwnode);
 	put_device(dev);
 	return dev ? dev_get_drvdata(dev) : NULL;
 }
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
index bb6586d0e5af..ed3829ae4ef1 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
@@ -754,17 +754,11 @@ struct dsaf_misc_op *hns_misc_op_get(struct dsaf_device *dsaf_dev)
 	return (void *)misc_op;
 }
 
-static int hns_dsaf_dev_match(struct device *dev, const void *fwnode)
-{
-	return dev->fwnode == fwnode;
-}
-
 struct
 platform_device *hns_dsaf_find_platform_device(struct fwnode_handle *fwnode)
 {
 	struct device *dev;
 
-	dev = bus_find_device(&platform_bus_type, NULL,
-			      fwnode, hns_dsaf_dev_match);
+	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
 	return dev ? to_platform_device(dev) : NULL;
 }
diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index c8efe60e2465..0526efbc4922 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -85,11 +85,6 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
 }
 EXPORT_SYMBOL_GPL(usb_role_switch_get_role);
 
-static int switch_fwnode_match(struct device *dev, const void *fwnode)
-{
-	return dev_fwnode(dev) == fwnode;
-}
-
 static void *usb_role_switch_match(struct device_connection *con, int ep,
 				   void *data)
 {
@@ -99,8 +94,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
 		if (con->id && !fwnode_property_present(con->fwnode, con->id))
 			return NULL;
 
-		dev = class_find_device(role_class, NULL, con->fwnode,
-					switch_fwnode_match);
+		dev = class_find_device_by_fwnode(role_class, con->fwnode);
 	} else {
 		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
 	}
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 9b0d15b487e5..94a3eda62add 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -205,11 +205,6 @@ static void typec_altmode_put_partner(struct altmode *altmode)
 	put_device(&adev->dev);
 }
 
-static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
-{
-	return dev_fwnode(dev) == fwnode;
-}
-
 static void *typec_port_match(struct device_connection *con, int ep, void *data)
 {
 	struct device *dev;
@@ -219,8 +214,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
 	 * we need to return ERR_PTR(-PROBE_DEFER) when there is no device.
 	 */
 	if (con->fwnode)
-		return class_find_device(typec_class, NULL, con->fwnode,
-					 typec_port_fwnode_match);
+		return class_find_device_by_fwnode(typec_class, con->fwnode);
 
 	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 29d8d7ad41e6..7133fc1c285d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -166,6 +166,7 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
 
 int device_match_name(struct device *dev, const void *name);
 int device_match_of_node(struct device *dev, const void *np);
+int device_match_fwnode(struct device *dev, const void *fwnode);
 
 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
 		     int (*fn)(struct device *dev, void *data));
@@ -198,6 +199,18 @@ 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);
 }
 
+/**
+ * bus_find_device_by_fwnode : device iterator for locating a particular device
+ * matching the fwnode.
+ * @bus: bus type
+ * @fwnode: fwnode of the device to match.
+ */
+static inline struct device *
+bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)
+{
+	return bus_find_device(bus, NULL, fwnode, device_match_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,
@@ -391,6 +404,19 @@ driver_find_device_by_of_node(struct device_driver *drv,
 	return driver_find_device(drv, NULL, np, device_match_of_node);
 }
 
+/**
+ * driver_find_device_by_fwnode- device iterator for locating a particular device
+ * by fwnode pointer.
+ * @driver: the driver we're iterating
+ * @fwnode: fwnode pointer to match.
+ */
+static inline struct device *
+driver_find_device_by_fwnode(struct device_driver *drv,
+			     const struct fwnode_handle *fwnode)
+{
+	return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
+}
+
 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);
@@ -544,6 +570,19 @@ 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);
 }
 
+/**
+ * class_find_device_by_fwnode : device iterator for locating a particular device
+ * matching the fwnode.
+ * @class: class type
+ * @fwnode: fwnode of the device to match.
+ */
+static inline struct device *
+class_find_device_by_fwnode(struct class *class,
+			    const struct fwnode_handle *fwnode)
+{
+	return class_find_device(class, NULL, fwnode, device_match_fwnode);
+}
+
 struct class_attribute {
 	struct attribute attr;
 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
-- 
2.21.0

[PATCH v3 4/7] drivers: Introduce device lookup variants by device type

[Suzuki K Poulose]

Add a helper to match a device by its type and provide wrappers
for {bus/class/driver}_find_device() APIs.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-usb@vger.kernel.org
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/base/core.c               | 15 ++++++-------
 drivers/hwtracing/intel_th/core.c | 10 +--------
 drivers/misc/mei/main.c           |  9 +-------
 drivers/s390/crypto/zcrypt_api.c  | 11 +--------
 drivers/tty/tty_io.c              |  8 +------
 drivers/usb/core/devio.c          |  8 +------
 include/linux/device.h            | 37 +++++++++++++++++++++++++++++++
 7 files changed, 49 insertions(+), 49 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index e8f81a667545..3abc32b60c0a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2867,13 +2867,6 @@ struct device *device_create_with_groups(struct class *class,
 }
 EXPORT_SYMBOL_GPL(device_create_with_groups);
 
-static int __match_devt(struct device *dev, const void *data)
-{
-	const dev_t *devt = data;
-
-	return dev->devt == *devt;
-}
-
 /**
  * device_destroy - removes a device that was created with device_create()
  * @class: pointer to the struct class that this device was registered with
@@ -2886,7 +2879,7 @@ void device_destroy(struct class *class, dev_t devt)
 {
 	struct device *dev;
 
-	dev = class_find_device(class, NULL, &devt, __match_devt);
+	dev = class_find_device_by_devt(class, devt);
 	if (dev) {
 		put_device(dev);
 		device_unregister(dev);
@@ -3374,3 +3367,9 @@ int device_match_fwnode(struct device *dev, const void *fwnode)
 	return dev_fwnode(dev) == fwnode;
 }
 EXPORT_SYMBOL_GPL(device_match_fwnode);
+
+int device_match_devt(struct device *dev, const void *pdevt)
+{
+	return dev->devt == *(dev_t *)pdevt;
+}
+EXPORT_SYMBOL_GPL(device_match_devt);
diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 55922896d862..d5c1821b31c6 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -789,12 +789,6 @@ static int intel_th_populate(struct intel_th *th)
 	return 0;
 }
 
-static int match_devt(struct device *dev, const void *data)
-{
-	dev_t devt = (dev_t)(unsigned long)(void *)data;
-	return dev->devt == devt;
-}
-
 static int intel_th_output_open(struct inode *inode, struct file *file)
 {
 	const struct file_operations *fops;
@@ -802,9 +796,7 @@ static int intel_th_output_open(struct inode *inode, struct file *file)
 	struct device *dev;
 	int err;
 
-	dev = bus_find_device(&intel_th_bus, NULL,
-			      (void *)(unsigned long)inode->i_rdev,
-			      match_devt);
+	dev = bus_find_device_by_devt(&intel_th_bus, inode->i_rdev);
 	if (!dev || !dev->driver)
 		return -ENODEV;
 
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index f894d1f8a53e..7310b476323c 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -858,13 +858,6 @@ static ssize_t dev_state_show(struct device *device,
 }
 static DEVICE_ATTR_RO(dev_state);
 
-static int match_devt(struct device *dev, const void *data)
-{
-	const dev_t *devt = data;
-
-	return dev->devt == *devt;
-}
-
 /**
  * dev_set_devstate: set to new device state and notify sysfs file.
  *
@@ -880,7 +873,7 @@ void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
 
 	dev->dev_state = state;
 
-	clsdev = class_find_device(mei_class, NULL, &dev->cdev.dev, match_devt);
+	clsdev = class_find_device_by_devt(mei_class, dev->cdev.dev);
 	if (clsdev) {
 		sysfs_notify(&clsdev->kobj, NULL, "dev_state");
 		put_device(clsdev);
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 38a5a47b8c9c..150f6236c9bb 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -133,12 +133,6 @@ struct zcdn_device {
 static int zcdn_create(const char *name);
 static int zcdn_destroy(const char *name);
 
-/* helper function, matches the devt value for find_zcdndev_by_devt() */
-static int __match_zcdn_devt(struct device *dev, const void *data)
-{
-	return dev->devt == *((dev_t *) data);
-}
-
 /*
  * Find zcdn device by name.
  * Returns reference to the zcdn device which needs to be released
@@ -158,10 +152,7 @@ static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
  */
 static inline struct zcdn_device *find_zcdndev_by_devt(dev_t devt)
 {
-	struct device *dev =
-		class_find_device(zcrypt_class, NULL,
-				  (void *) &devt,
-				  __match_zcdn_devt);
+	struct device *dev = class_find_device_by_devt(zcrypt_class, devt);
 
 	return dev ? to_zcdn_dev(dev) : NULL;
 }
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 566728fbaf3c..802c1210558f 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2952,17 +2952,11 @@ void do_SAK(struct tty_struct *tty)
 
 EXPORT_SYMBOL(do_SAK);
 
-static int dev_match_devt(struct device *dev, const void *data)
-{
-	const dev_t *devt = data;
-	return dev->devt == *devt;
-}
-
 /* Must put_device() after it's unused! */
 static struct device *tty_get_device(struct tty_struct *tty)
 {
 	dev_t devt = tty_devnum(tty);
-	return class_find_device(tty_class, NULL, &devt, dev_match_devt);
+	return class_find_device_by_devt(tty_class, devt);
 }
 
 
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index b265ab5405f9..60268aee93a8 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -942,17 +942,11 @@ static int parse_usbdevfs_streams(struct usb_dev_state *ps,
 	return ret;
 }
 
-static int match_devt(struct device *dev, const void *data)
-{
-	return dev->devt == (dev_t)(unsigned long)(void *)data;
-}
-
 static struct usb_device *usbdev_lookup_by_devt(dev_t devt)
 {
 	struct device *dev;
 
-	dev = bus_find_device(&usb_bus_type, NULL,
-			      (void *) (unsigned long) devt, match_devt);
+	dev = bus_find_device_by_devt(&usb_bus_type, devt);
 	if (!dev)
 		return NULL;
 	return to_usb_device(dev);
diff --git a/include/linux/device.h b/include/linux/device.h
index 7133fc1c285d..93b2f55ef44e 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -167,6 +167,7 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
 int device_match_name(struct device *dev, const void *name);
 int device_match_of_node(struct device *dev, const void *np);
 int device_match_fwnode(struct device *dev, const void *fwnode);
+int device_match_devt(struct device *dev, const void *pdevt);
 
 int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
 		     int (*fn)(struct device *dev, void *data));
@@ -211,6 +212,18 @@ bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwno
 	return bus_find_device(bus, NULL, fwnode, device_match_fwnode);
 }
 
+/**
+ * bus_find_device_by_devt : device iterator for locating a particular device
+ * matching the device type.
+ * @bus: bus type
+ * @devt: device type of the device to match.
+ */
+static inline struct device *bus_find_device_by_devt(struct bus_type *bus,
+						     dev_t devt)
+{
+	return bus_find_device(bus, NULL, &devt, device_match_devt);
+}
+
 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,
@@ -417,6 +430,18 @@ driver_find_device_by_fwnode(struct device_driver *drv,
 	return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
 }
 
+/**
+ * driver_find_device_by_devt- device iterator for locating a particular device
+ * by devt.
+ * @driver: the driver we're iterating
+ * @devt: devt pointer to match.
+ */
+static inline struct device *driver_find_device_by_devt(struct device_driver *drv,
+							dev_t devt)
+{
+	return driver_find_device(drv, NULL, &devt, device_match_devt);
+}
+
 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);
@@ -583,6 +608,18 @@ class_find_device_by_fwnode(struct class *class,
 	return class_find_device(class, NULL, fwnode, device_match_fwnode);
 }
 
+/**
+ * class_find_device_by_devt : device iterator for locating a particular device
+ * matching the device type.
+ * @class: class type
+ * @devt: device type of the device to match.
+ */
+static inline struct device *class_find_device_by_devt(struct class *class,
+						       dev_t devt)
+{
+	return class_find_device(class, NULL, &devt, device_match_devt);
+}
+
 struct class_attribute {
 	struct attribute attr;
 	ssize_t (*show)(struct class *class, struct class_attribute *attr,
-- 
2.21.0

Re: [PATCH v3 3/7] drivers: Introduce device lookup variants by fwnode

[Robin Murphy]

On 23/07/2019 23:18, Suzuki K Poulose wrote:
> Add a helper to match the firmware node handle of a device and provide
> wrappers for {bus/class/driver}_find_device() APIs to avoid proliferation
> of duplicate custom match functions.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Doug Ledford <dledford@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: linux-usb@vger.kernel.org
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Joe Perches <joe@perches.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
>   drivers/base/core.c                           |  6 +++
>   drivers/base/devcon.c                         |  8 +---
>   .../hwtracing/coresight/coresight-platform.c  | 11 +-----
>   drivers/hwtracing/coresight/coresight-priv.h  |  2 -
>   drivers/hwtracing/coresight/coresight.c       |  4 +-
>   drivers/infiniband/hw/hns/hns_roce_hw_v1.c    |  8 +---
>   drivers/iommu/arm-smmu-v3.c                   |  9 +----
>   drivers/iommu/arm-smmu.c                      |  9 +----

For the Arm SMMU drivers,

Acked-by: Robin Murphy <robin.murphy@arm.com>

>   .../ethernet/hisilicon/hns/hns_dsaf_misc.c    |  8 +---
>   drivers/usb/roles/class.c                     |  8 +---
>   drivers/usb/typec/class.c                     |  8 +---
>   include/linux/device.h                        | 39 +++++++++++++++++++
>   12 files changed, 57 insertions(+), 63 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index fb83647d685a..e8f81a667545 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3368,3 +3368,9 @@ int device_match_of_node(struct device *dev, const void *np)
>   	return dev->of_node == np;
>   }
>   EXPORT_SYMBOL_GPL(device_match_of_node);
> +
> +int device_match_fwnode(struct device *dev, const void *fwnode)
> +{
> +	return dev_fwnode(dev) == fwnode;
> +}
> +EXPORT_SYMBOL_GPL(device_match_fwnode);
> diff --git a/drivers/base/devcon.c b/drivers/base/devcon.c
> index 09f28479b243..1d488dc5dd0c 100644
> --- a/drivers/base/devcon.c
> +++ b/drivers/base/devcon.c
> @@ -133,19 +133,13 @@ static struct bus_type *generic_match_buses[] = {
>   	NULL,
>   };
>   
> -static int device_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>   static void *device_connection_fwnode_match(struct device_connection *con)
>   {
>   	struct bus_type *bus;
>   	struct device *dev;
>   
>   	for (bus = generic_match_buses[0]; bus; bus++) {
> -		dev = bus_find_device(bus, NULL, (void *)con->fwnode,
> -				      device_fwnode_match);
> +		dev = bus_find_device_by_fwnode(bus, con->fwnode);
>   		if (dev && !strncmp(dev_name(dev), con->id, strlen(con->id)))
>   			return dev;
>   
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index dad7d96c5943..3c5bee429105 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -37,11 +37,6 @@ static int coresight_alloc_conns(struct device *dev,
>   	return 0;
>   }
>   
> -int coresight_device_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>   static struct device *
>   coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>   {
> @@ -51,8 +46,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>   	 * If we have a non-configurable replicator, it will be found on the
>   	 * platform bus.
>   	 */
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, coresight_device_fwnode_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>   	if (dev)
>   		return dev;
>   
> @@ -60,8 +54,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>   	 * We have a configurable component - circle through the AMBA bus
>   	 * looking for the device that matches the endpoint node.
>   	 */
> -	return bus_find_device(&amba_bustype, NULL,
> -			       fwnode, coresight_device_fwnode_match);
> +	return bus_find_device_by_fwnode(&amba_bustype, fwnode);
>   }
>   
>   #ifdef CONFIG_OF
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 7d401790dd7e..61d7f9ff054d 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -202,6 +202,4 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
>   
>   void coresight_release_platform_data(struct coresight_platform_data *pdata);
>   
> -int coresight_device_fwnode_match(struct device *dev, const void *fwnode);
> -
>   #endif
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 55db77f6410b..6453c67a4d01 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -1046,9 +1046,7 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)
>   		struct coresight_connection *conn = &csdev->pdata->conns[i];
>   		struct device *dev = NULL;
>   
> -		dev = bus_find_device(&coresight_bustype, NULL,
> -				      (void *)conn->child_fwnode,
> -				      coresight_device_fwnode_match);
> +		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
>   		if (dev) {
>   			conn->child_dev = to_coresight_device(dev);
>   			/* and put reference from 'bus_find_device()' */
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> index 81e6dedb1e02..fa05e943038a 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> @@ -4499,19 +4499,13 @@ static const struct acpi_device_id hns_roce_acpi_match[] = {
>   };
>   MODULE_DEVICE_TABLE(acpi, hns_roce_acpi_match);
>   
> -static int hns_roce_node_match(struct device *dev, const void *fwnode)
> -{
> -	return dev->fwnode == fwnode;
> -}
> -
>   static struct
>   platform_device *hns_roce_find_pdev(struct fwnode_handle *fwnode)
>   {
>   	struct device *dev;
>   
>   	/* get the 'device' corresponding to the matching 'fwnode' */
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, hns_roce_node_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>   	/* get the platform device */
>   	return dev ? to_platform_device(dev) : NULL;
>   }
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index a9a9fabd3968..6f0e13fa5e1a 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2034,16 +2034,11 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
>   
>   static struct platform_driver arm_smmu_driver;
>   
> -static int arm_smmu_match_node(struct device *dev, const void *data)
> -{
> -	return dev->fwnode == data;
> -}
> -
>   static
>   struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>   {
> -	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
> -						fwnode, arm_smmu_match_node);
> +	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
> +							  fwnode);
>   	put_device(dev);
>   	return dev ? dev_get_drvdata(dev) : NULL;
>   }
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 64977c131ee6..aa06498f291d 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1426,16 +1426,11 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>   	}
>   }
>   
> -static int arm_smmu_match_node(struct device *dev, const void *data)
> -{
> -	return dev->fwnode == data;
> -}
> -
>   static
>   struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>   {
> -	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
> -						fwnode, arm_smmu_match_node);
> +	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
> +							  fwnode);
>   	put_device(dev);
>   	return dev ? dev_get_drvdata(dev) : NULL;
>   }
> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> index bb6586d0e5af..ed3829ae4ef1 100644
> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> @@ -754,17 +754,11 @@ struct dsaf_misc_op *hns_misc_op_get(struct dsaf_device *dsaf_dev)
>   	return (void *)misc_op;
>   }
>   
> -static int hns_dsaf_dev_match(struct device *dev, const void *fwnode)
> -{
> -	return dev->fwnode == fwnode;
> -}
> -
>   struct
>   platform_device *hns_dsaf_find_platform_device(struct fwnode_handle *fwnode)
>   {
>   	struct device *dev;
>   
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, hns_dsaf_dev_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>   	return dev ? to_platform_device(dev) : NULL;
>   }
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index c8efe60e2465..0526efbc4922 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -85,11 +85,6 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
>   }
>   EXPORT_SYMBOL_GPL(usb_role_switch_get_role);
>   
> -static int switch_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>   static void *usb_role_switch_match(struct device_connection *con, int ep,
>   				   void *data)
>   {
> @@ -99,8 +94,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
>   		if (con->id && !fwnode_property_present(con->fwnode, con->id))
>   			return NULL;
>   
> -		dev = class_find_device(role_class, NULL, con->fwnode,
> -					switch_fwnode_match);
> +		dev = class_find_device_by_fwnode(role_class, con->fwnode);
>   	} else {
>   		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
>   	}
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index 9b0d15b487e5..94a3eda62add 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -205,11 +205,6 @@ static void typec_altmode_put_partner(struct altmode *altmode)
>   	put_device(&adev->dev);
>   }
>   
> -static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>   static void *typec_port_match(struct device_connection *con, int ep, void *data)
>   {
>   	struct device *dev;
> @@ -219,8 +214,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
>   	 * we need to return ERR_PTR(-PROBE_DEFER) when there is no device.
>   	 */
>   	if (con->fwnode)
> -		return class_find_device(typec_class, NULL, con->fwnode,
> -					 typec_port_fwnode_match);
> +		return class_find_device_by_fwnode(typec_class, con->fwnode);
>   
>   	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
>   
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 29d8d7ad41e6..7133fc1c285d 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -166,6 +166,7 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
>   
>   int device_match_name(struct device *dev, const void *name);
>   int device_match_of_node(struct device *dev, const void *np);
> +int device_match_fwnode(struct device *dev, const void *fwnode);
>   
>   int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
>   		     int (*fn)(struct device *dev, void *data));
> @@ -198,6 +199,18 @@ 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);
>   }
>   
> +/**
> + * bus_find_device_by_fwnode : device iterator for locating a particular device
> + * matching the fwnode.
> + * @bus: bus type
> + * @fwnode: fwnode of the device to match.
> + */
> +static inline struct device *
> +bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)
> +{
> +	return bus_find_device(bus, NULL, fwnode, device_match_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,
> @@ -391,6 +404,19 @@ driver_find_device_by_of_node(struct device_driver *drv,
>   	return driver_find_device(drv, NULL, np, device_match_of_node);
>   }
>   
> +/**
> + * driver_find_device_by_fwnode- device iterator for locating a particular device
> + * by fwnode pointer.
> + * @driver: the driver we're iterating
> + * @fwnode: fwnode pointer to match.
> + */
> +static inline struct device *
> +driver_find_device_by_fwnode(struct device_driver *drv,
> +			     const struct fwnode_handle *fwnode)
> +{
> +	return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
> +}
> +
>   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);
> @@ -544,6 +570,19 @@ 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);
>   }
>   
> +/**
> + * class_find_device_by_fwnode : device iterator for locating a particular device
> + * matching the fwnode.
> + * @class: class type
> + * @fwnode: fwnode of the device to match.
> + */
> +static inline struct device *
> +class_find_device_by_fwnode(struct class *class,
> +			    const struct fwnode_handle *fwnode)
> +{
> +	return class_find_device(class, NULL, fwnode, device_match_fwnode);
> +}
> +
>   struct class_attribute {
>   	struct attribute attr;
>   	ssize_t (*show)(struct class *class, struct class_attribute *attr,
> 

Re: [PATCH v3 1/7] drivers: Introduce device lookup variants by name

[Alexandre Belloni]

On 23/07/2019 23:18:32+0100, Suzuki K Poulose wrote:
> Add a helper to match the device name for device lookup. Also
> reuse this generic exported helper for the existing bus_find_device_by_name().
> and add similar variants for driver/class.
> 
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Alexander Aring <alex.aring@gmail.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Dan Murphy <dmurphy@ti.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Harald Freudenberger <freude@linux.ibm.com>
> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: linux-leds@vger.kernel.org
> Cc: linux-rtc@vger.kernel.org
> Cc: linux-usb@vger.kernel.org
> Cc: linux-wpan@vger.kernel.org
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Stefan Schmidt <stefan@datenfreihafen.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
>  drivers/base/bus.c               | 24 ------------------
>  drivers/base/core.c              |  6 +++++
>  drivers/hwtracing/stm/core.c     |  9 +------
>  drivers/leds/led-class.c         |  9 +------
>  drivers/rtc/interface.c          | 11 +--------
>  drivers/s390/cio/ccwgroup.c      | 10 +-------
>  drivers/s390/cio/device.c        | 15 +-----------
>  drivers/s390/crypto/zcrypt_api.c | 11 +--------
>  drivers/usb/roles/class.c        |  8 +-----
>  drivers/usb/typec/class.c        |  8 +-----
>  include/linux/device.h           | 42 +++++++++++++++++++++++++++++---
>  net/ieee802154/core.c            |  7 +-----
>  12 files changed, 54 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> index df3cac739813..a1d1e8256324 100644
> --- a/drivers/base/bus.c
> +++ b/drivers/base/bus.c
> @@ -342,30 +342,6 @@ struct device *bus_find_device(struct bus_type *bus,
>  }
>  EXPORT_SYMBOL_GPL(bus_find_device);
>  
> -static int match_name(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	return sysfs_streq(name, dev_name(dev));
> -}
> -
> -/**
> - * bus_find_device_by_name - device iterator for locating a particular device of a specific name
> - * @bus: bus type
> - * @start: Device to begin with
> - * @name: name of the device to match
> - *
> - * This is similar to the bus_find_device() function above, but it handles
> - * searching by a name automatically, no need to write another strcmp matching
> - * function.
> - */
> -struct device *bus_find_device_by_name(struct bus_type *bus,
> -				       struct device *start, const char *name)
> -{
> -	return bus_find_device(bus, start, (void *)name, match_name);
> -}
> -EXPORT_SYMBOL_GPL(bus_find_device_by_name);
> -
>  /**
>   * subsys_find_device_by_id - find a device with a specific enumeration number
>   * @subsys: subsystem
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index da84a73f2ba6..fb83647d685a 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3357,6 +3357,12 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
>  }
>  EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
>  
> +int device_match_name(struct device *dev, const void *name)
> +{
> +	return sysfs_streq(dev_name(dev), name);
> +}
> +EXPORT_SYMBOL_GPL(device_match_name);
> +
>  int device_match_of_node(struct device *dev, const void *np)
>  {
>  	return dev->of_node == np;
> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
> index e55b902560de..2b6bd42632e8 100644
> --- a/drivers/hwtracing/stm/core.c
> +++ b/drivers/hwtracing/stm/core.c
> @@ -89,13 +89,6 @@ static struct class stm_class = {
>  	.dev_groups	= stm_groups,
>  };
>  
> -static int stm_dev_match(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	return sysfs_streq(name, dev_name(dev));
> -}
> -
>  /**
>   * stm_find_device() - find stm device by name
>   * @buf:	character buffer containing the name
> @@ -116,7 +109,7 @@ struct stm_device *stm_find_device(const char *buf)
>  	if (!stm_core_up)
>  		return NULL;
>  
> -	dev = class_find_device(&stm_class, NULL, buf, stm_dev_match);
> +	dev = class_find_device_by_name(&stm_class, buf);
>  	if (!dev)
>  		return NULL;
>  
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 4793e77808e2..d54c8e4d8954 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -213,13 +213,6 @@ static int led_resume(struct device *dev)
>  
>  static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
>  
> -static int match_name(struct device *dev, const void *data)
> -{
> -	if (!dev_name(dev))
> -		return 0;
> -	return !strcmp(dev_name(dev), (char *)data);
> -}
> -
>  static int led_classdev_next_name(const char *init_name, char *name,
>  				  size_t len)
>  {
> @@ -230,7 +223,7 @@ static int led_classdev_next_name(const char *init_name, char *name,
>  	strlcpy(name, init_name, len);
>  
>  	while ((ret < len) &&
> -	       (dev = class_find_device(leds_class, NULL, name, match_name))) {
> +	       (dev = class_find_device_by_name(leds_class, name))) {
>  		put_device(dev);
>  		ret = snprintf(name, len, "%s_%u", init_name, ++i);
>  	}
> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index 72b7ddc43116..c93ef33b01d3 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -663,21 +663,12 @@ void rtc_update_irq(struct rtc_device *rtc,
>  }
>  EXPORT_SYMBOL_GPL(rtc_update_irq);
>  
> -static int __rtc_match(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	if (strcmp(dev_name(dev), name) == 0)
> -		return 1;
> -	return 0;
> -}
> -
>  struct rtc_device *rtc_class_open(const char *name)
>  {
>  	struct device *dev;
>  	struct rtc_device *rtc = NULL;
>  
> -	dev = class_find_device(rtc_class, NULL, name, __rtc_match);
> +	dev = class_find_device_by_name(rtc_class, name);
>  	if (dev)
>  		rtc = to_rtc_device(dev);
>  
> diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
> index c522e9313c50..d843e362c167 100644
> --- a/drivers/s390/cio/ccwgroup.c
> +++ b/drivers/s390/cio/ccwgroup.c
> @@ -608,13 +608,6 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
>  }
>  EXPORT_SYMBOL(ccwgroup_driver_unregister);
>  
> -static int __ccwgroupdev_check_busid(struct device *dev, const void *id)
> -{
> -	const char *bus_id = id;
> -
> -	return (strcmp(bus_id, dev_name(dev)) == 0);
> -}
> -
>  /**
>   * get_ccwgroupdev_by_busid() - obtain device from a bus id
>   * @gdrv: driver the device is owned by
> @@ -631,8 +624,7 @@ struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
>  {
>  	struct device *dev;
>  
> -	dev = driver_find_device(&gdrv->driver, NULL, bus_id,
> -				 __ccwgroupdev_check_busid);
> +	dev = driver_find_device_by_name(&gdrv->driver, bus_id);
>  
>  	return dev ? to_ccwgroupdev(dev) : NULL;
>  }
> diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
> index c421899be20f..131430bd48d9 100644
> --- a/drivers/s390/cio/device.c
> +++ b/drivers/s390/cio/device.c
> @@ -1695,18 +1695,6 @@ int ccw_device_force_console(struct ccw_device *cdev)
>  EXPORT_SYMBOL_GPL(ccw_device_force_console);
>  #endif
>  
> -/*
> - * get ccw_device matching the busid, but only if owned by cdrv
> - */
> -static int
> -__ccwdev_check_busid(struct device *dev, const void *id)
> -{
> -	const char *bus_id = id;
> -
> -	return (strcmp(bus_id, dev_name(dev)) == 0);
> -}
> -
> -
>  /**
>   * get_ccwdev_by_busid() - obtain device from a bus id
>   * @cdrv: driver the device is owned by
> @@ -1723,8 +1711,7 @@ struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
>  {
>  	struct device *dev;
>  
> -	dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
> -				 __ccwdev_check_busid);
> +	dev = driver_find_device_by_name(&cdrv->driver, bus_id);
>  
>  	return dev ? to_ccwdev(dev) : NULL;
>  }
> diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
> index 1058b4b5cc1e..38a5a47b8c9c 100644
> --- a/drivers/s390/crypto/zcrypt_api.c
> +++ b/drivers/s390/crypto/zcrypt_api.c
> @@ -133,12 +133,6 @@ struct zcdn_device {
>  static int zcdn_create(const char *name);
>  static int zcdn_destroy(const char *name);
>  
> -/* helper function, matches the name for find_zcdndev_by_name() */
> -static int __match_zcdn_name(struct device *dev, const void *data)
> -{
> -	return strcmp(dev_name(dev), (const char *)data) == 0;
> -}
> -
>  /* helper function, matches the devt value for find_zcdndev_by_devt() */
>  static int __match_zcdn_devt(struct device *dev, const void *data)
>  {
> @@ -152,10 +146,7 @@ static int __match_zcdn_devt(struct device *dev, const void *data)
>   */
>  static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
>  {
> -	struct device *dev =
> -		class_find_device(zcrypt_class, NULL,
> -				  (void *) name,
> -				  __match_zcdn_name);
> +	struct device *dev = class_find_device_by_name(zcrypt_class, name);
>  
>  	return dev ? to_zcdn_dev(dev) : NULL;
>  }
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index 86defca6623e..c8efe60e2465 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -90,11 +90,6 @@ static int switch_fwnode_match(struct device *dev, const void *fwnode)
>  	return dev_fwnode(dev) == fwnode;
>  }
>  
> -static int switch_name_match(struct device *dev, const void *name)
> -{
> -	return !strcmp((const char *)name, dev_name(dev));
> -}
> -
>  static void *usb_role_switch_match(struct device_connection *con, int ep,
>  				   void *data)
>  {
> @@ -107,8 +102,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
>  		dev = class_find_device(role_class, NULL, con->fwnode,
>  					switch_fwnode_match);
>  	} else {
> -		dev = class_find_device(role_class, NULL, con->endpoint[ep],
> -					switch_name_match);
> +		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
>  	}
>  
>  	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index a18285a990a8..9b0d15b487e5 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -210,11 +210,6 @@ static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
>  	return dev_fwnode(dev) == fwnode;
>  }
>  
> -static int typec_port_name_match(struct device *dev, const void *name)
> -{
> -	return !strcmp((const char *)name, dev_name(dev));
> -}
> -
>  static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  {
>  	struct device *dev;
> @@ -227,8 +222,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  		return class_find_device(typec_class, NULL, con->fwnode,
>  					 typec_port_fwnode_match);
>  
> -	dev = class_find_device(typec_class, NULL, con->endpoint[ep],
> -				typec_port_name_match);
> +	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
>  
>  	return dev ? dev : ERR_PTR(-EPROBE_DEFER);
>  }
> diff --git a/include/linux/device.h b/include/linux/device.h
> index c330b75c6c57..3ba376b8b456 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -164,6 +164,7 @@ void subsys_dev_iter_init(struct subsys_dev_iter *iter,
>  struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
>  void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
>  
> +int device_match_name(struct device *dev, const void *name);
>  int device_match_of_node(struct device *dev, const void *np);
>  
>  int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
> @@ -171,9 +172,20 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
>  struct device *bus_find_device(struct bus_type *bus, struct device *start,
>  			       const void *data,
>  			       int (*match)(struct device *dev, const void *data));
> -struct device *bus_find_device_by_name(struct bus_type *bus,
> -				       struct device *start,
> -				       const char *name);
> +/**
> + * bus_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @bus: bus type
> + * @start: Device to begin with
> + * @name: name of the device to match
> + */
> +static inline struct device *bus_find_device_by_name(struct bus_type *bus,
> +						     struct device *start,
> +						     const char *name)
> +{
> +	return bus_find_device(bus, start, name, device_match_name);
> +}
> +
>  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,
> @@ -342,6 +354,18 @@ struct device *driver_find_device(struct device_driver *drv,
>  				  struct device *start, const void *data,
>  				  int (*match)(struct device *dev, const void *data));
>  
> +/**
> + * driver_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @driver: the driver we're iterating
> + * @name: name of the device to match
> + */
> +static inline struct device *driver_find_device_by_name(struct device_driver *drv,
> +							const char *name)
> +{
> +	return driver_find_device(drv, NULL, name, device_match_name);
> +}
> +
>  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);
> @@ -471,6 +495,18 @@ extern struct device *class_find_device(struct class *class,
>  					struct device *start, const void *data,
>  					int (*match)(struct device *, const void *));
>  
> +/**
> + * class_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @class: class type
> + * @name: name of the device to match
> + */
> +static inline struct device *class_find_device_by_name(struct class *class,
> +						       const char *name)
> +{
> +	return class_find_device(class, NULL, name, device_match_name);
> +}
> +
>  struct class_attribute {
>  	struct attribute attr;
>  	ssize_t (*show)(struct class *class, struct class_attribute *attr,
> diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
> index 60b7ac56a1f5..de259b5170ab 100644
> --- a/net/ieee802154/core.c
> +++ b/net/ieee802154/core.c
> @@ -23,11 +23,6 @@
>  LIST_HEAD(cfg802154_rdev_list);
>  int cfg802154_rdev_list_generation;
>  
> -static int wpan_phy_match(struct device *dev, const void *data)
> -{
> -	return !strcmp(dev_name(dev), (const char *)data);
> -}
> -
>  struct wpan_phy *wpan_phy_find(const char *str)
>  {
>  	struct device *dev;
> @@ -35,7 +30,7 @@ struct wpan_phy *wpan_phy_find(const char *str)
>  	if (WARN_ON(!str))
>  		return NULL;
>  
> -	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
> +	dev = class_find_device_by_name(&wpan_phy_class, str);
>  	if (!dev)
>  		return NULL;
>  
> -- 
> 2.21.0
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v3 3/7] drivers: Introduce device lookup variants by fwnode

[Mathieu Poirier]

On Tue, Jul 23, 2019 at 11:18:34PM +0100, Suzuki K Poulose wrote:
> Add a helper to match the firmware node handle of a device and provide
> wrappers for {bus/class/driver}_find_device() APIs to avoid proliferation
> of duplicate custom match functions.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Doug Ledford <dledford@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: linux-usb@vger.kernel.org
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Joe Perches <joe@perches.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
>  drivers/base/core.c                           |  6 +++
>  drivers/base/devcon.c                         |  8 +---

>  .../hwtracing/coresight/coresight-platform.c  | 11 +-----
>  drivers/hwtracing/coresight/coresight-priv.h  |  2 -
>  drivers/hwtracing/coresight/coresight.c       |  4 +-

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

>  drivers/infiniband/hw/hns/hns_roce_hw_v1.c    |  8 +---
>  drivers/iommu/arm-smmu-v3.c                   |  9 +----
>  drivers/iommu/arm-smmu.c                      |  9 +----
>  .../ethernet/hisilicon/hns/hns_dsaf_misc.c    |  8 +---
>  drivers/usb/roles/class.c                     |  8 +---
>  drivers/usb/typec/class.c                     |  8 +---
>  include/linux/device.h                        | 39 +++++++++++++++++++
>  12 files changed, 57 insertions(+), 63 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index fb83647d685a..e8f81a667545 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3368,3 +3368,9 @@ int device_match_of_node(struct device *dev, const void *np)
>  	return dev->of_node == np;
>  }
>  EXPORT_SYMBOL_GPL(device_match_of_node);
> +
> +int device_match_fwnode(struct device *dev, const void *fwnode)
> +{
> +	return dev_fwnode(dev) == fwnode;
> +}
> +EXPORT_SYMBOL_GPL(device_match_fwnode);
> diff --git a/drivers/base/devcon.c b/drivers/base/devcon.c
> index 09f28479b243..1d488dc5dd0c 100644
> --- a/drivers/base/devcon.c
> +++ b/drivers/base/devcon.c
> @@ -133,19 +133,13 @@ static struct bus_type *generic_match_buses[] = {
>  	NULL,
>  };
>  
> -static int device_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static void *device_connection_fwnode_match(struct device_connection *con)
>  {
>  	struct bus_type *bus;
>  	struct device *dev;
>  
>  	for (bus = generic_match_buses[0]; bus; bus++) {
> -		dev = bus_find_device(bus, NULL, (void *)con->fwnode,
> -				      device_fwnode_match);
> +		dev = bus_find_device_by_fwnode(bus, con->fwnode);
>  		if (dev && !strncmp(dev_name(dev), con->id, strlen(con->id)))
>  			return dev;
>  
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index dad7d96c5943..3c5bee429105 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -37,11 +37,6 @@ static int coresight_alloc_conns(struct device *dev,
>  	return 0;
>  }
>  
> -int coresight_device_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static struct device *
>  coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>  {
> @@ -51,8 +46,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>  	 * If we have a non-configurable replicator, it will be found on the
>  	 * platform bus.
>  	 */
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, coresight_device_fwnode_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>  	if (dev)
>  		return dev;
>  
> @@ -60,8 +54,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>  	 * We have a configurable component - circle through the AMBA bus
>  	 * looking for the device that matches the endpoint node.
>  	 */
> -	return bus_find_device(&amba_bustype, NULL,
> -			       fwnode, coresight_device_fwnode_match);
> +	return bus_find_device_by_fwnode(&amba_bustype, fwnode);
>  }
>  
>  #ifdef CONFIG_OF
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 7d401790dd7e..61d7f9ff054d 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -202,6 +202,4 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
>  
>  void coresight_release_platform_data(struct coresight_platform_data *pdata);
>  
> -int coresight_device_fwnode_match(struct device *dev, const void *fwnode);
> -
>  #endif
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 55db77f6410b..6453c67a4d01 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -1046,9 +1046,7 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)
>  		struct coresight_connection *conn = &csdev->pdata->conns[i];
>  		struct device *dev = NULL;
>  
> -		dev = bus_find_device(&coresight_bustype, NULL,
> -				      (void *)conn->child_fwnode,
> -				      coresight_device_fwnode_match);
> +		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
>  		if (dev) {
>  			conn->child_dev = to_coresight_device(dev);
>  			/* and put reference from 'bus_find_device()' */
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> index 81e6dedb1e02..fa05e943038a 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> @@ -4499,19 +4499,13 @@ static const struct acpi_device_id hns_roce_acpi_match[] = {
>  };
>  MODULE_DEVICE_TABLE(acpi, hns_roce_acpi_match);
>  
> -static int hns_roce_node_match(struct device *dev, const void *fwnode)
> -{
> -	return dev->fwnode == fwnode;
> -}
> -
>  static struct
>  platform_device *hns_roce_find_pdev(struct fwnode_handle *fwnode)
>  {
>  	struct device *dev;
>  
>  	/* get the 'device' corresponding to the matching 'fwnode' */
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, hns_roce_node_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>  	/* get the platform device */
>  	return dev ? to_platform_device(dev) : NULL;
>  }
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index a9a9fabd3968..6f0e13fa5e1a 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2034,16 +2034,11 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
>  
>  static struct platform_driver arm_smmu_driver;
>  
> -static int arm_smmu_match_node(struct device *dev, const void *data)
> -{
> -	return dev->fwnode == data;
> -}
> -
>  static
>  struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>  {
> -	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
> -						fwnode, arm_smmu_match_node);
> +	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
> +							  fwnode);
>  	put_device(dev);
>  	return dev ? dev_get_drvdata(dev) : NULL;
>  }
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 64977c131ee6..aa06498f291d 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1426,16 +1426,11 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>  	}
>  }
>  
> -static int arm_smmu_match_node(struct device *dev, const void *data)
> -{
> -	return dev->fwnode == data;
> -}
> -
>  static
>  struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>  {
> -	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
> -						fwnode, arm_smmu_match_node);
> +	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
> +							  fwnode);
>  	put_device(dev);
>  	return dev ? dev_get_drvdata(dev) : NULL;
>  }
> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> index bb6586d0e5af..ed3829ae4ef1 100644
> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> @@ -754,17 +754,11 @@ struct dsaf_misc_op *hns_misc_op_get(struct dsaf_device *dsaf_dev)
>  	return (void *)misc_op;
>  }
>  
> -static int hns_dsaf_dev_match(struct device *dev, const void *fwnode)
> -{
> -	return dev->fwnode == fwnode;
> -}
> -
>  struct
>  platform_device *hns_dsaf_find_platform_device(struct fwnode_handle *fwnode)
>  {
>  	struct device *dev;
>  
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, hns_dsaf_dev_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>  	return dev ? to_platform_device(dev) : NULL;
>  }
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index c8efe60e2465..0526efbc4922 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -85,11 +85,6 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
>  }
>  EXPORT_SYMBOL_GPL(usb_role_switch_get_role);
>  
> -static int switch_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static void *usb_role_switch_match(struct device_connection *con, int ep,
>  				   void *data)
>  {
> @@ -99,8 +94,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
>  		if (con->id && !fwnode_property_present(con->fwnode, con->id))
>  			return NULL;
>  
> -		dev = class_find_device(role_class, NULL, con->fwnode,
> -					switch_fwnode_match);
> +		dev = class_find_device_by_fwnode(role_class, con->fwnode);
>  	} else {
>  		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
>  	}
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index 9b0d15b487e5..94a3eda62add 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -205,11 +205,6 @@ static void typec_altmode_put_partner(struct altmode *altmode)
>  	put_device(&adev->dev);
>  }
>  
> -static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  {
>  	struct device *dev;
> @@ -219,8 +214,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  	 * we need to return ERR_PTR(-PROBE_DEFER) when there is no device.
>  	 */
>  	if (con->fwnode)
> -		return class_find_device(typec_class, NULL, con->fwnode,
> -					 typec_port_fwnode_match);
> +		return class_find_device_by_fwnode(typec_class, con->fwnode);
>  
>  	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
>  
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 29d8d7ad41e6..7133fc1c285d 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -166,6 +166,7 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
>  
>  int device_match_name(struct device *dev, const void *name);
>  int device_match_of_node(struct device *dev, const void *np);
> +int device_match_fwnode(struct device *dev, const void *fwnode);
>  
>  int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
>  		     int (*fn)(struct device *dev, void *data));
> @@ -198,6 +199,18 @@ 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);
>  }
>  
> +/**
> + * bus_find_device_by_fwnode : device iterator for locating a particular device
> + * matching the fwnode.
> + * @bus: bus type
> + * @fwnode: fwnode of the device to match.
> + */
> +static inline struct device *
> +bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)
> +{
> +	return bus_find_device(bus, NULL, fwnode, device_match_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,
> @@ -391,6 +404,19 @@ driver_find_device_by_of_node(struct device_driver *drv,
>  	return driver_find_device(drv, NULL, np, device_match_of_node);
>  }
>  
> +/**
> + * driver_find_device_by_fwnode- device iterator for locating a particular device
> + * by fwnode pointer.
> + * @driver: the driver we're iterating
> + * @fwnode: fwnode pointer to match.
> + */
> +static inline struct device *
> +driver_find_device_by_fwnode(struct device_driver *drv,
> +			     const struct fwnode_handle *fwnode)
> +{
> +	return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
> +}
> +
>  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);
> @@ -544,6 +570,19 @@ 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);
>  }
>  
> +/**
> + * class_find_device_by_fwnode : device iterator for locating a particular device
> + * matching the fwnode.
> + * @class: class type
> + * @fwnode: fwnode of the device to match.
> + */
> +static inline struct device *
> +class_find_device_by_fwnode(struct class *class,
> +			    const struct fwnode_handle *fwnode)
> +{
> +	return class_find_device(class, NULL, fwnode, device_match_fwnode);
> +}
> +
>  struct class_attribute {
>  	struct attribute attr;
>  	ssize_t (*show)(struct class *class, struct class_attribute *attr,
> -- 
> 2.21.0
> 

Re: [PATCH v3 3/7] drivers: Introduce device lookup variants by fwnode

[Heikki Krogerus]

On Tue, Jul 23, 2019 at 11:18:34PM +0100, Suzuki K Poulose wrote:
> Add a helper to match the firmware node handle of a device and provide
> wrappers for {bus/class/driver}_find_device() APIs to avoid proliferation
> of duplicate custom match functions.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Doug Ledford <dledford@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: linux-usb@vger.kernel.org
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Ulf Hansson <ulf.hansson@linaro.org>
> Cc: Joe Perches <joe@perches.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/base/core.c                           |  6 +++
>  drivers/base/devcon.c                         |  8 +---
>  .../hwtracing/coresight/coresight-platform.c  | 11 +-----
>  drivers/hwtracing/coresight/coresight-priv.h  |  2 -
>  drivers/hwtracing/coresight/coresight.c       |  4 +-
>  drivers/infiniband/hw/hns/hns_roce_hw_v1.c    |  8 +---
>  drivers/iommu/arm-smmu-v3.c                   |  9 +----
>  drivers/iommu/arm-smmu.c                      |  9 +----
>  .../ethernet/hisilicon/hns/hns_dsaf_misc.c    |  8 +---
>  drivers/usb/roles/class.c                     |  8 +---
>  drivers/usb/typec/class.c                     |  8 +---
>  include/linux/device.h                        | 39 +++++++++++++++++++
>  12 files changed, 57 insertions(+), 63 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index fb83647d685a..e8f81a667545 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3368,3 +3368,9 @@ int device_match_of_node(struct device *dev, const void *np)
>  	return dev->of_node == np;
>  }
>  EXPORT_SYMBOL_GPL(device_match_of_node);
> +
> +int device_match_fwnode(struct device *dev, const void *fwnode)
> +{
> +	return dev_fwnode(dev) == fwnode;
> +}
> +EXPORT_SYMBOL_GPL(device_match_fwnode);
> diff --git a/drivers/base/devcon.c b/drivers/base/devcon.c
> index 09f28479b243..1d488dc5dd0c 100644
> --- a/drivers/base/devcon.c
> +++ b/drivers/base/devcon.c
> @@ -133,19 +133,13 @@ static struct bus_type *generic_match_buses[] = {
>  	NULL,
>  };
>  
> -static int device_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static void *device_connection_fwnode_match(struct device_connection *con)
>  {
>  	struct bus_type *bus;
>  	struct device *dev;
>  
>  	for (bus = generic_match_buses[0]; bus; bus++) {
> -		dev = bus_find_device(bus, NULL, (void *)con->fwnode,
> -				      device_fwnode_match);
> +		dev = bus_find_device_by_fwnode(bus, con->fwnode);
>  		if (dev && !strncmp(dev_name(dev), con->id, strlen(con->id)))
>  			return dev;
>  
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index dad7d96c5943..3c5bee429105 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -37,11 +37,6 @@ static int coresight_alloc_conns(struct device *dev,
>  	return 0;
>  }
>  
> -int coresight_device_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static struct device *
>  coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>  {
> @@ -51,8 +46,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>  	 * If we have a non-configurable replicator, it will be found on the
>  	 * platform bus.
>  	 */
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, coresight_device_fwnode_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>  	if (dev)
>  		return dev;
>  
> @@ -60,8 +54,7 @@ coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
>  	 * We have a configurable component - circle through the AMBA bus
>  	 * looking for the device that matches the endpoint node.
>  	 */
> -	return bus_find_device(&amba_bustype, NULL,
> -			       fwnode, coresight_device_fwnode_match);
> +	return bus_find_device_by_fwnode(&amba_bustype, fwnode);
>  }
>  
>  #ifdef CONFIG_OF
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 7d401790dd7e..61d7f9ff054d 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -202,6 +202,4 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
>  
>  void coresight_release_platform_data(struct coresight_platform_data *pdata);
>  
> -int coresight_device_fwnode_match(struct device *dev, const void *fwnode);
> -
>  #endif
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 55db77f6410b..6453c67a4d01 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -1046,9 +1046,7 @@ static void coresight_fixup_device_conns(struct coresight_device *csdev)
>  		struct coresight_connection *conn = &csdev->pdata->conns[i];
>  		struct device *dev = NULL;
>  
> -		dev = bus_find_device(&coresight_bustype, NULL,
> -				      (void *)conn->child_fwnode,
> -				      coresight_device_fwnode_match);
> +		dev = bus_find_device_by_fwnode(&coresight_bustype, conn->child_fwnode);
>  		if (dev) {
>  			conn->child_dev = to_coresight_device(dev);
>  			/* and put reference from 'bus_find_device()' */
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> index 81e6dedb1e02..fa05e943038a 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> @@ -4499,19 +4499,13 @@ static const struct acpi_device_id hns_roce_acpi_match[] = {
>  };
>  MODULE_DEVICE_TABLE(acpi, hns_roce_acpi_match);
>  
> -static int hns_roce_node_match(struct device *dev, const void *fwnode)
> -{
> -	return dev->fwnode == fwnode;
> -}
> -
>  static struct
>  platform_device *hns_roce_find_pdev(struct fwnode_handle *fwnode)
>  {
>  	struct device *dev;
>  
>  	/* get the 'device' corresponding to the matching 'fwnode' */
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, hns_roce_node_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>  	/* get the platform device */
>  	return dev ? to_platform_device(dev) : NULL;
>  }
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index a9a9fabd3968..6f0e13fa5e1a 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2034,16 +2034,11 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
>  
>  static struct platform_driver arm_smmu_driver;
>  
> -static int arm_smmu_match_node(struct device *dev, const void *data)
> -{
> -	return dev->fwnode == data;
> -}
> -
>  static
>  struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>  {
> -	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
> -						fwnode, arm_smmu_match_node);
> +	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
> +							  fwnode);
>  	put_device(dev);
>  	return dev ? dev_get_drvdata(dev) : NULL;
>  }
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 64977c131ee6..aa06498f291d 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1426,16 +1426,11 @@ static bool arm_smmu_capable(enum iommu_cap cap)
>  	}
>  }
>  
> -static int arm_smmu_match_node(struct device *dev, const void *data)
> -{
> -	return dev->fwnode == data;
> -}
> -
>  static
>  struct arm_smmu_device *arm_smmu_get_by_fwnode(struct fwnode_handle *fwnode)
>  {
> -	struct device *dev = driver_find_device(&arm_smmu_driver.driver, NULL,
> -						fwnode, arm_smmu_match_node);
> +	struct device *dev = driver_find_device_by_fwnode(&arm_smmu_driver.driver,
> +							  fwnode);
>  	put_device(dev);
>  	return dev ? dev_get_drvdata(dev) : NULL;
>  }
> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> index bb6586d0e5af..ed3829ae4ef1 100644
> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_misc.c
> @@ -754,17 +754,11 @@ struct dsaf_misc_op *hns_misc_op_get(struct dsaf_device *dsaf_dev)
>  	return (void *)misc_op;
>  }
>  
> -static int hns_dsaf_dev_match(struct device *dev, const void *fwnode)
> -{
> -	return dev->fwnode == fwnode;
> -}
> -
>  struct
>  platform_device *hns_dsaf_find_platform_device(struct fwnode_handle *fwnode)
>  {
>  	struct device *dev;
>  
> -	dev = bus_find_device(&platform_bus_type, NULL,
> -			      fwnode, hns_dsaf_dev_match);
> +	dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
>  	return dev ? to_platform_device(dev) : NULL;
>  }
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index c8efe60e2465..0526efbc4922 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -85,11 +85,6 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
>  }
>  EXPORT_SYMBOL_GPL(usb_role_switch_get_role);
>  
> -static int switch_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static void *usb_role_switch_match(struct device_connection *con, int ep,
>  				   void *data)
>  {
> @@ -99,8 +94,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
>  		if (con->id && !fwnode_property_present(con->fwnode, con->id))
>  			return NULL;
>  
> -		dev = class_find_device(role_class, NULL, con->fwnode,
> -					switch_fwnode_match);
> +		dev = class_find_device_by_fwnode(role_class, con->fwnode);
>  	} else {
>  		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
>  	}
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index 9b0d15b487e5..94a3eda62add 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -205,11 +205,6 @@ static void typec_altmode_put_partner(struct altmode *altmode)
>  	put_device(&adev->dev);
>  }
>  
> -static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
> -{
> -	return dev_fwnode(dev) == fwnode;
> -}
> -
>  static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  {
>  	struct device *dev;
> @@ -219,8 +214,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  	 * we need to return ERR_PTR(-PROBE_DEFER) when there is no device.
>  	 */
>  	if (con->fwnode)
> -		return class_find_device(typec_class, NULL, con->fwnode,
> -					 typec_port_fwnode_match);
> +		return class_find_device_by_fwnode(typec_class, con->fwnode);
>  
>  	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
>  
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 29d8d7ad41e6..7133fc1c285d 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -166,6 +166,7 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
>  
>  int device_match_name(struct device *dev, const void *name);
>  int device_match_of_node(struct device *dev, const void *np);
> +int device_match_fwnode(struct device *dev, const void *fwnode);
>  
>  int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
>  		     int (*fn)(struct device *dev, void *data));
> @@ -198,6 +199,18 @@ 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);
>  }
>  
> +/**
> + * bus_find_device_by_fwnode : device iterator for locating a particular device
> + * matching the fwnode.
> + * @bus: bus type
> + * @fwnode: fwnode of the device to match.
> + */
> +static inline struct device *
> +bus_find_device_by_fwnode(struct bus_type *bus, const struct fwnode_handle *fwnode)
> +{
> +	return bus_find_device(bus, NULL, fwnode, device_match_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,
> @@ -391,6 +404,19 @@ driver_find_device_by_of_node(struct device_driver *drv,
>  	return driver_find_device(drv, NULL, np, device_match_of_node);
>  }
>  
> +/**
> + * driver_find_device_by_fwnode- device iterator for locating a particular device
> + * by fwnode pointer.
> + * @driver: the driver we're iterating
> + * @fwnode: fwnode pointer to match.
> + */
> +static inline struct device *
> +driver_find_device_by_fwnode(struct device_driver *drv,
> +			     const struct fwnode_handle *fwnode)
> +{
> +	return driver_find_device(drv, NULL, fwnode, device_match_fwnode);
> +}
> +
>  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);
> @@ -544,6 +570,19 @@ 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);
>  }
>  
> +/**
> + * class_find_device_by_fwnode : device iterator for locating a particular device
> + * matching the fwnode.
> + * @class: class type
> + * @fwnode: fwnode of the device to match.
> + */
> +static inline struct device *
> +class_find_device_by_fwnode(struct class *class,
> +			    const struct fwnode_handle *fwnode)
> +{
> +	return class_find_device(class, NULL, fwnode, device_match_fwnode);
> +}
> +
>  struct class_attribute {
>  	struct attribute attr;
>  	ssize_t (*show)(struct class *class, struct class_attribute *attr,
> -- 
> 2.21.0

thanks,

-- 
heikki

Re: [PATCH v3 1/7] drivers: Introduce device lookup variants by name

[Heikki Krogerus]

On Tue, Jul 23, 2019 at 11:18:32PM +0100, Suzuki K Poulose wrote:
> Add a helper to match the device name for device lookup. Also
> reuse this generic exported helper for the existing bus_find_device_by_name().
> and add similar variants for driver/class.
> 
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Alexander Aring <alex.aring@gmail.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Dan Murphy <dmurphy@ti.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Harald Freudenberger <freude@linux.ibm.com>
> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: linux-leds@vger.kernel.org
> Cc: linux-rtc@vger.kernel.org
> Cc: linux-usb@vger.kernel.org
> Cc: linux-wpan@vger.kernel.org
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Stefan Schmidt <stefan@datenfreihafen.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.coM>

> ---
>  drivers/base/bus.c               | 24 ------------------
>  drivers/base/core.c              |  6 +++++
>  drivers/hwtracing/stm/core.c     |  9 +------
>  drivers/leds/led-class.c         |  9 +------
>  drivers/rtc/interface.c          | 11 +--------
>  drivers/s390/cio/ccwgroup.c      | 10 +-------
>  drivers/s390/cio/device.c        | 15 +-----------
>  drivers/s390/crypto/zcrypt_api.c | 11 +--------
>  drivers/usb/roles/class.c        |  8 +-----
>  drivers/usb/typec/class.c        |  8 +-----
>  include/linux/device.h           | 42 +++++++++++++++++++++++++++++---
>  net/ieee802154/core.c            |  7 +-----
>  12 files changed, 54 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> index df3cac739813..a1d1e8256324 100644
> --- a/drivers/base/bus.c
> +++ b/drivers/base/bus.c
> @@ -342,30 +342,6 @@ struct device *bus_find_device(struct bus_type *bus,
>  }
>  EXPORT_SYMBOL_GPL(bus_find_device);
>  
> -static int match_name(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	return sysfs_streq(name, dev_name(dev));
> -}
> -
> -/**
> - * bus_find_device_by_name - device iterator for locating a particular device of a specific name
> - * @bus: bus type
> - * @start: Device to begin with
> - * @name: name of the device to match
> - *
> - * This is similar to the bus_find_device() function above, but it handles
> - * searching by a name automatically, no need to write another strcmp matching
> - * function.
> - */
> -struct device *bus_find_device_by_name(struct bus_type *bus,
> -				       struct device *start, const char *name)
> -{
> -	return bus_find_device(bus, start, (void *)name, match_name);
> -}
> -EXPORT_SYMBOL_GPL(bus_find_device_by_name);
> -
>  /**
>   * subsys_find_device_by_id - find a device with a specific enumeration number
>   * @subsys: subsystem
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index da84a73f2ba6..fb83647d685a 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3357,6 +3357,12 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
>  }
>  EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
>  
> +int device_match_name(struct device *dev, const void *name)
> +{
> +	return sysfs_streq(dev_name(dev), name);
> +}
> +EXPORT_SYMBOL_GPL(device_match_name);
> +
>  int device_match_of_node(struct device *dev, const void *np)
>  {
>  	return dev->of_node == np;
> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
> index e55b902560de..2b6bd42632e8 100644
> --- a/drivers/hwtracing/stm/core.c
> +++ b/drivers/hwtracing/stm/core.c
> @@ -89,13 +89,6 @@ static struct class stm_class = {
>  	.dev_groups	= stm_groups,
>  };
>  
> -static int stm_dev_match(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	return sysfs_streq(name, dev_name(dev));
> -}
> -
>  /**
>   * stm_find_device() - find stm device by name
>   * @buf:	character buffer containing the name
> @@ -116,7 +109,7 @@ struct stm_device *stm_find_device(const char *buf)
>  	if (!stm_core_up)
>  		return NULL;
>  
> -	dev = class_find_device(&stm_class, NULL, buf, stm_dev_match);
> +	dev = class_find_device_by_name(&stm_class, buf);
>  	if (!dev)
>  		return NULL;
>  
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 4793e77808e2..d54c8e4d8954 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -213,13 +213,6 @@ static int led_resume(struct device *dev)
>  
>  static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
>  
> -static int match_name(struct device *dev, const void *data)
> -{
> -	if (!dev_name(dev))
> -		return 0;
> -	return !strcmp(dev_name(dev), (char *)data);
> -}
> -
>  static int led_classdev_next_name(const char *init_name, char *name,
>  				  size_t len)
>  {
> @@ -230,7 +223,7 @@ static int led_classdev_next_name(const char *init_name, char *name,
>  	strlcpy(name, init_name, len);
>  
>  	while ((ret < len) &&
> -	       (dev = class_find_device(leds_class, NULL, name, match_name))) {
> +	       (dev = class_find_device_by_name(leds_class, name))) {
>  		put_device(dev);
>  		ret = snprintf(name, len, "%s_%u", init_name, ++i);
>  	}
> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index 72b7ddc43116..c93ef33b01d3 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -663,21 +663,12 @@ void rtc_update_irq(struct rtc_device *rtc,
>  }
>  EXPORT_SYMBOL_GPL(rtc_update_irq);
>  
> -static int __rtc_match(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	if (strcmp(dev_name(dev), name) == 0)
> -		return 1;
> -	return 0;
> -}
> -
>  struct rtc_device *rtc_class_open(const char *name)
>  {
>  	struct device *dev;
>  	struct rtc_device *rtc = NULL;
>  
> -	dev = class_find_device(rtc_class, NULL, name, __rtc_match);
> +	dev = class_find_device_by_name(rtc_class, name);
>  	if (dev)
>  		rtc = to_rtc_device(dev);
>  
> diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
> index c522e9313c50..d843e362c167 100644
> --- a/drivers/s390/cio/ccwgroup.c
> +++ b/drivers/s390/cio/ccwgroup.c
> @@ -608,13 +608,6 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
>  }
>  EXPORT_SYMBOL(ccwgroup_driver_unregister);
>  
> -static int __ccwgroupdev_check_busid(struct device *dev, const void *id)
> -{
> -	const char *bus_id = id;
> -
> -	return (strcmp(bus_id, dev_name(dev)) == 0);
> -}
> -
>  /**
>   * get_ccwgroupdev_by_busid() - obtain device from a bus id
>   * @gdrv: driver the device is owned by
> @@ -631,8 +624,7 @@ struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
>  {
>  	struct device *dev;
>  
> -	dev = driver_find_device(&gdrv->driver, NULL, bus_id,
> -				 __ccwgroupdev_check_busid);
> +	dev = driver_find_device_by_name(&gdrv->driver, bus_id);
>  
>  	return dev ? to_ccwgroupdev(dev) : NULL;
>  }
> diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
> index c421899be20f..131430bd48d9 100644
> --- a/drivers/s390/cio/device.c
> +++ b/drivers/s390/cio/device.c
> @@ -1695,18 +1695,6 @@ int ccw_device_force_console(struct ccw_device *cdev)
>  EXPORT_SYMBOL_GPL(ccw_device_force_console);
>  #endif
>  
> -/*
> - * get ccw_device matching the busid, but only if owned by cdrv
> - */
> -static int
> -__ccwdev_check_busid(struct device *dev, const void *id)
> -{
> -	const char *bus_id = id;
> -
> -	return (strcmp(bus_id, dev_name(dev)) == 0);
> -}
> -
> -
>  /**
>   * get_ccwdev_by_busid() - obtain device from a bus id
>   * @cdrv: driver the device is owned by
> @@ -1723,8 +1711,7 @@ struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
>  {
>  	struct device *dev;
>  
> -	dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
> -				 __ccwdev_check_busid);
> +	dev = driver_find_device_by_name(&cdrv->driver, bus_id);
>  
>  	return dev ? to_ccwdev(dev) : NULL;
>  }
> diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
> index 1058b4b5cc1e..38a5a47b8c9c 100644
> --- a/drivers/s390/crypto/zcrypt_api.c
> +++ b/drivers/s390/crypto/zcrypt_api.c
> @@ -133,12 +133,6 @@ struct zcdn_device {
>  static int zcdn_create(const char *name);
>  static int zcdn_destroy(const char *name);
>  
> -/* helper function, matches the name for find_zcdndev_by_name() */
> -static int __match_zcdn_name(struct device *dev, const void *data)
> -{
> -	return strcmp(dev_name(dev), (const char *)data) == 0;
> -}
> -
>  /* helper function, matches the devt value for find_zcdndev_by_devt() */
>  static int __match_zcdn_devt(struct device *dev, const void *data)
>  {
> @@ -152,10 +146,7 @@ static int __match_zcdn_devt(struct device *dev, const void *data)
>   */
>  static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
>  {
> -	struct device *dev =
> -		class_find_device(zcrypt_class, NULL,
> -				  (void *) name,
> -				  __match_zcdn_name);
> +	struct device *dev = class_find_device_by_name(zcrypt_class, name);
>  
>  	return dev ? to_zcdn_dev(dev) : NULL;
>  }
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index 86defca6623e..c8efe60e2465 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -90,11 +90,6 @@ static int switch_fwnode_match(struct device *dev, const void *fwnode)
>  	return dev_fwnode(dev) == fwnode;
>  }
>  
> -static int switch_name_match(struct device *dev, const void *name)
> -{
> -	return !strcmp((const char *)name, dev_name(dev));
> -}
> -
>  static void *usb_role_switch_match(struct device_connection *con, int ep,
>  				   void *data)
>  {
> @@ -107,8 +102,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
>  		dev = class_find_device(role_class, NULL, con->fwnode,
>  					switch_fwnode_match);
>  	} else {
> -		dev = class_find_device(role_class, NULL, con->endpoint[ep],
> -					switch_name_match);
> +		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
>  	}
>  
>  	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index a18285a990a8..9b0d15b487e5 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -210,11 +210,6 @@ static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
>  	return dev_fwnode(dev) == fwnode;
>  }
>  
> -static int typec_port_name_match(struct device *dev, const void *name)
> -{
> -	return !strcmp((const char *)name, dev_name(dev));
> -}
> -
>  static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  {
>  	struct device *dev;
> @@ -227,8 +222,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  		return class_find_device(typec_class, NULL, con->fwnode,
>  					 typec_port_fwnode_match);
>  
> -	dev = class_find_device(typec_class, NULL, con->endpoint[ep],
> -				typec_port_name_match);
> +	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
>  
>  	return dev ? dev : ERR_PTR(-EPROBE_DEFER);
>  }
> diff --git a/include/linux/device.h b/include/linux/device.h
> index c330b75c6c57..3ba376b8b456 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -164,6 +164,7 @@ void subsys_dev_iter_init(struct subsys_dev_iter *iter,
>  struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
>  void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
>  
> +int device_match_name(struct device *dev, const void *name);
>  int device_match_of_node(struct device *dev, const void *np);
>  
>  int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
> @@ -171,9 +172,20 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
>  struct device *bus_find_device(struct bus_type *bus, struct device *start,
>  			       const void *data,
>  			       int (*match)(struct device *dev, const void *data));
> -struct device *bus_find_device_by_name(struct bus_type *bus,
> -				       struct device *start,
> -				       const char *name);
> +/**
> + * bus_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @bus: bus type
> + * @start: Device to begin with
> + * @name: name of the device to match
> + */
> +static inline struct device *bus_find_device_by_name(struct bus_type *bus,
> +						     struct device *start,
> +						     const char *name)
> +{
> +	return bus_find_device(bus, start, name, device_match_name);
> +}
> +
>  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,
> @@ -342,6 +354,18 @@ struct device *driver_find_device(struct device_driver *drv,
>  				  struct device *start, const void *data,
>  				  int (*match)(struct device *dev, const void *data));
>  
> +/**
> + * driver_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @driver: the driver we're iterating
> + * @name: name of the device to match
> + */
> +static inline struct device *driver_find_device_by_name(struct device_driver *drv,
> +							const char *name)
> +{
> +	return driver_find_device(drv, NULL, name, device_match_name);
> +}
> +
>  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);
> @@ -471,6 +495,18 @@ extern struct device *class_find_device(struct class *class,
>  					struct device *start, const void *data,
>  					int (*match)(struct device *, const void *));
>  
> +/**
> + * class_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @class: class type
> + * @name: name of the device to match
> + */
> +static inline struct device *class_find_device_by_name(struct class *class,
> +						       const char *name)
> +{
> +	return class_find_device(class, NULL, name, device_match_name);
> +}
> +
>  struct class_attribute {
>  	struct attribute attr;
>  	ssize_t (*show)(struct class *class, struct class_attribute *attr,
> diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
> index 60b7ac56a1f5..de259b5170ab 100644
> --- a/net/ieee802154/core.c
> +++ b/net/ieee802154/core.c
> @@ -23,11 +23,6 @@
>  LIST_HEAD(cfg802154_rdev_list);
>  int cfg802154_rdev_list_generation;
>  
> -static int wpan_phy_match(struct device *dev, const void *data)
> -{
> -	return !strcmp(dev_name(dev), (const char *)data);
> -}
> -
>  struct wpan_phy *wpan_phy_find(const char *str)
>  {
>  	struct device *dev;
> @@ -35,7 +30,7 @@ struct wpan_phy *wpan_phy_find(const char *str)
>  	if (WARN_ON(!str))
>  		return NULL;
>  
> -	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
> +	dev = class_find_device_by_name(&wpan_phy_class, str);
>  	if (!dev)
>  		return NULL;
>  
> -- 
> 2.21.0

thanks,

-- 
heikki