gpio: virtuser: stop using dev-sync-probe

dev-err-probe is an overengineered solution to a simple problem. Use a
combination of wait_for_probe() and device_is_bound() to synchronously
wait for the platform device to probe.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260327-gpio-kill-dev-sync-probe-v1-3-efac254f1a1d@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: Bartosz Golaszewski

drivers/gpio/Kconfig

@@ -2098,7 +2098,6 @@ config GPIO_VIRTUSER
 	select DEBUG_FS
 	select CONFIGFS_FS
 	select IRQ_WORK
-	select DEV_SYNC_PROBE
 	help
 	  Say Y here to enable the configurable, configfs-based virtual GPIO
 	  consumer testing driver.

drivers/gpio/gpio-virtuser.c

@@ -36,8 +36,6 @@
 #include <linux/string_helpers.h>
 #include <linux/types.h>
 
-#include "dev-sync-probe.h"
-
 #define GPIO_VIRTUSER_NAME_BUF_LEN 32
 
 static DEFINE_IDA(gpio_virtuser_ida);
@@ -978,7 +976,7 @@ static struct platform_driver gpio_virtuser_driver = {
 };
 
 struct gpio_virtuser_device {
-	struct dev_sync_probe_data probe_data;
+	struct platform_device *pdev;
 	struct config_group group;
 
 	int id;
@@ -1002,7 +1000,7 @@ gpio_virtuser_device_is_live(struct gpio_virtuser_device *dev)
 {
 	lockdep_assert_held(&dev->lock);
 
-	return !!dev->probe_data.pdev;
+	return !!dev->pdev;
 }
 
 struct gpio_virtuser_lookup {
@@ -1342,7 +1340,7 @@ gpio_virtuser_device_config_dev_name_show(struct config_item *item,
 
 	guard(mutex)(&dev->lock);
 
-	pdev = dev->probe_data.pdev;
+	pdev = dev->pdev;
 	if (pdev)
 		return sprintf(page, "%s\n", dev_name(&pdev->dev));
 
@@ -1450,6 +1448,7 @@ static int
 gpio_virtuser_device_activate(struct gpio_virtuser_device *dev)
 {
 	struct platform_device_info pdevinfo;
+	struct platform_device *pdev;
 	struct fwnode_handle *swnode;
 	int ret;
 
@@ -1471,12 +1470,23 @@ gpio_virtuser_device_activate(struct gpio_virtuser_device *dev)
 	if (ret)
 		goto err_remove_swnode;
 
-	ret = dev_sync_probe_register(&dev->probe_data, &pdevinfo);
-	if (ret)
+	pdev = platform_device_register_full(&pdevinfo);
+	if (IS_ERR(pdev)) {
+		ret = PTR_ERR(pdev);
 		goto err_remove_lookup_table;
+	}
+
+	wait_for_device_probe();
+	if (!device_is_bound(&pdev->dev)) {
+		ret = -ENXIO;
+		goto err_unregister_pdev;
+	}
 
+	dev->pdev = pdev;
 	return 0;
 
+err_unregister_pdev:
+	platform_device_unregister(pdev);
 err_remove_lookup_table:
 	gpio_virtuser_remove_lookup_table(dev);
 err_remove_swnode:
@@ -1492,8 +1502,9 @@ gpio_virtuser_device_deactivate(struct gpio_virtuser_device *dev)
 
 	lockdep_assert_held(&dev->lock);
 
-	swnode = dev_fwnode(&dev->probe_data.pdev->dev);
-	dev_sync_probe_unregister(&dev->probe_data);
+	swnode = dev_fwnode(&dev->pdev->dev);
+	platform_device_unregister(dev->pdev);
+	dev->pdev = NULL;
 	gpio_virtuser_remove_lookup_table(dev);
 	fwnode_remove_software_node(swnode);
 }
@@ -1723,7 +1734,6 @@ gpio_virtuser_config_make_device_group(struct config_group *group,
 				    &gpio_virtuser_device_config_group_type);
 	mutex_init(&dev->lock);
 	INIT_LIST_HEAD(&dev->lookup_list);
-	dev_sync_probe_init(&dev->probe_data);
 
 	return &no_free_ptr(dev)->group;
 }