soundwire: bus_type: introduce sdw_slave_type and sdw_master_type

this is a preparatory patch before the introduction of the
sdw_master_type. The SoundWire slave support is slightly modified with
the use of a sdw_slave_type, and the uevent handling move to
slave.c (since it's not necessary for the master).

No functionality change other than moving code around.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-3-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/bus_type.c

@@ -33,13 +33,21 @@ sdw_get_device_id(struct sdw_slave *slave, struct sdw_driver *drv)
 
 static int sdw_bus_match(struct device *dev, struct device_driver *ddrv)
 {
-	struct sdw_slave *slave = dev_to_sdw_dev(dev);
-	struct sdw_driver *drv = drv_to_sdw_driver(ddrv);
+	struct sdw_slave *slave;
+	struct sdw_driver *drv;
+	int ret = 0;
+
+	if (is_sdw_slave(dev)) {
+		slave = dev_to_sdw_dev(dev);
+		drv = drv_to_sdw_driver(ddrv);
 
-	return !!sdw_get_device_id(slave, drv);
+		ret = !!sdw_get_device_id(slave, drv);
+	}
+	return ret;
 }
 
-int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
+static int sdw_slave_modalias(const struct sdw_slave *slave, char *buf,
+			      size_t size)
 {
 	/* modalias is sdw:m<mfg_id>p<part_id> */
 
@@ -47,7 +55,7 @@ int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
 			slave->id.mfg_id, slave->id.part_id);
 }
 
-static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
+int sdw_slave_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
 	char modalias[32];
@@ -63,7 +71,6 @@ static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
 struct bus_type sdw_bus_type = {
 	.name = "soundwire",
 	.match = sdw_bus_match,
-	.uevent = sdw_uevent,
 };
 EXPORT_SYMBOL_GPL(sdw_bus_type);
 

drivers/soundwire/slave.c

@@ -14,6 +14,12 @@ static void sdw_slave_release(struct device *dev)
 	kfree(slave);
 }
 
+struct device_type sdw_slave_type = {
+	.name =		"sdw_slave",
+	.release =	sdw_slave_release,
+	.uevent =	sdw_slave_uevent,
+};
+
 static int sdw_slave_add(struct sdw_bus *bus,
 			 struct sdw_slave_id *id, struct fwnode_handle *fwnode)
 {
@@ -41,9 +47,9 @@ static int sdw_slave_add(struct sdw_bus *bus,
 			     id->class_id, id->unique_id);
 	}
 
-	slave->dev.release = sdw_slave_release;
 	slave->dev.bus = &sdw_bus_type;
 	slave->dev.of_node = of_node_get(to_of_node(fwnode));
+	slave->dev.type = &sdw_slave_type;
 	slave->bus = bus;
 	slave->status = SDW_SLAVE_UNATTACHED;
 	init_completion(&slave->enumeration_complete);

include/linux/soundwire/sdw_type.h

@@ -5,6 +5,13 @@
 #define __SOUNDWIRE_TYPES_H
 
 extern struct bus_type sdw_bus_type;
+extern struct device_type sdw_slave_type;
+extern struct device_type sdw_master_type;
+
+static inline int is_sdw_slave(const struct device *dev)
+{
+	return dev->type == &sdw_slave_type;
+}
 
 #define drv_to_sdw_driver(_drv) container_of(_drv, struct sdw_driver, driver)
 
@@ -14,7 +21,7 @@ extern struct bus_type sdw_bus_type;
 int __sdw_register_driver(struct sdw_driver *drv, struct module *owner);
 void sdw_unregister_driver(struct sdw_driver *drv);
 
-int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size);
+int sdw_slave_uevent(struct device *dev, struct kobj_uevent_env *env);
 
 /**
  * module_sdw_driver() - Helper macro for registering a Soundwire driver