reset: gpio: convert the driver to using the auxiliary bus

As the reset-gpio devices are purely virtual and never instantiated from
real firmware nodes, let's convert the driver to using the - more
fitting - auxiliary bus.

Reviewed-by: Philipp Zabel <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Acked-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>
Signed-off-by: Philipp Zabel <[e-mail]>

drivers/reset/Kconfig

···
 config RESET_GPIO
 	tristate "GPIO reset controller"
 	depends on GPIOLIB
+	select AUXILIARY_BUS
 	help
 	  This enables a generic reset controller for resets attached via
 	  GPIOs.  Typically for OF platforms this driver expects "reset-gpios"

drivers/reset/core.c

···
 
 #include <linux/acpi.h>
 #include <linux/atomic.h>
+#include <linux/auxiliary_bus.h>
 #include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/err.h>
···
 #include <linux/kref.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/reset-controller.h>
 #include <linux/slab.h>
···
 	if (!lookup)
 		return -ENOMEM;
 
-	lookup->dev_id = kasprintf(GFP_KERNEL, "reset-gpio.%d", id);
+	lookup->dev_id = kasprintf(GFP_KERNEL, "reset.gpio.%d", id);
 	if (!lookup->dev_id)
 		return -ENOMEM;
 
···
 static int __reset_add_reset_gpio_device(const struct of_phandle_args *args)
 {
 	struct reset_gpio_lookup *rgpio_dev;
-	struct platform_device *pdev;
+	struct auxiliary_device *adev;
 	int id, ret;
 
 	/*
···
 	 * Hold reference as long as rgpio_dev memory is valid.
 	 */
 	of_node_get(rgpio_dev->of_args.np);
-	pdev = platform_device_register_data(gpio_device_to_device(gdev),
-					     "reset-gpio", id,
-					     &rgpio_dev->of_args,
-					     sizeof(rgpio_dev->of_args));
-	ret = PTR_ERR_OR_ZERO(pdev);
+	adev = auxiliary_device_create(gpio_device_to_device(gdev), "reset",
+				       "gpio", &rgpio_dev->of_args, id);
+	ret = PTR_ERR_OR_ZERO(adev);
 	if (ret)
 		goto err_put;
 

drivers/reset/reset-gpio.c

···
 // SPDX-License-Identifier: GPL-2.0
 
+#include <linux/auxiliary_bus.h>
 #include <linux/gpio/consumer.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/platform_device.h>
 #include <linux/reset-controller.h>
 
 struct reset_gpio_priv {
···
 	of_node_put(data);
 }
 
-static int reset_gpio_probe(struct platform_device *pdev)
+static int reset_gpio_probe(struct auxiliary_device *adev,
+			    const struct auxiliary_device_id *id)
 {
-	struct device *dev = &pdev->dev;
+	struct device *dev = &adev->dev;
 	struct of_phandle_args *platdata = dev_get_platdata(dev);
 	struct reset_gpio_priv *priv;
 	int ret;
···
 	if (!priv)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, &priv->rc);
+	auxiliary_set_drvdata(adev, &priv->rc);
 
 	priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(priv->reset))
···
 	return devm_reset_controller_register(dev, &priv->rc);
 }
 
-static const struct platform_device_id reset_gpio_ids[] = {
-	{ .name = "reset-gpio", },
+static const struct auxiliary_device_id reset_gpio_ids[] = {
+	{ .name = "reset.gpio" },
 	{}
 };
-MODULE_DEVICE_TABLE(platform, reset_gpio_ids);
+MODULE_DEVICE_TABLE(auxiliary, reset_gpio_ids);
 
-static struct platform_driver reset_gpio_driver = {
+static struct auxiliary_driver reset_gpio_driver = {
 	.probe		= reset_gpio_probe,
 	.id_table	= reset_gpio_ids,
 	.driver	= {
 		.name = "reset-gpio",
 	},
 };
-module_platform_driver(reset_gpio_driver);
+module_auxiliary_driver(reset_gpio_driver);
 
 MODULE_AUTHOR("Krzysztof Kozlowski <[e-mail]>");
 MODULE_DESCRIPTION("Generic GPIO reset driver");