soundwire: sysfs: have the driver core handle the creation of the device groups

The driver core supports the ability to handle the creation and removal
of device-specific sysfs files in a race-free manner.  Take advantage of
that by converting this driver to use this by moving the sysfs
attributes into a group and assigning the dev_groups pointer to it.

Cc: Vinod Koul <vkoul@kernel.org>
Cc: Bard Liao <yung-chuan.liao@linux.intel.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Sanyog Kale <sanyog.r.kale@intel.com>
Cc: alsa-devel@alsa-project.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-By: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Link: https://lore.kernel.org/r/2024013030-worsening-rocket-a3cb@gregkhSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/bus_type.c

@@ -221,6 +221,7 @@ int __sdw_register_driver(struct sdw_driver *drv, struct module *owner)
 	drv->driver.probe = sdw_drv_probe;
 	drv->driver.remove = sdw_drv_remove;
 	drv->driver.shutdown = sdw_drv_shutdown;
+	drv->driver.dev_groups = sdw_attr_groups;
 
 	return driver_register(&drv->driver);
 }

drivers/soundwire/sysfs_local.h

@@ -11,6 +11,9 @@
 /* basic attributes to report status of Slave (attachment, dev_num) */
 extern const struct attribute_group *sdw_slave_status_attr_groups[];
 
+/* attributes for all soundwire devices */
+extern const struct attribute_group *sdw_attr_groups[];
+
 /* additional device-managed properties reported after driver probe */
 int sdw_slave_sysfs_init(struct sdw_slave *slave);
 int sdw_slave_sysfs_dpn_init(struct sdw_slave *slave);

drivers/soundwire/sysfs_slave.c

@@ -214,7 +214,7 @@ static const struct attribute_group dp0_group = {
 	.name = "dp0",
 };
 
-static const struct attribute_group *slave_groups[] = {
+const struct attribute_group *sdw_attr_groups[] = {
 	&slave_attr_group,
 	&sdw_slave_dev_attr_group,
 	&dp0_group,
@@ -225,10 +225,6 @@ int sdw_slave_sysfs_init(struct sdw_slave *slave)
 {
 	int ret;
 
-	ret = devm_device_add_groups(&slave->dev, slave_groups);
-	if (ret < 0)
-		return ret;
-
 	if (slave->prop.source_ports || slave->prop.sink_ports) {
 		ret = sdw_slave_sysfs_dpn_init(slave);
 		if (ret < 0)