Commit a5a38765 authored by Rob Herring's avatar Rob Herring
Browse files

bus: vexpress-config: simplify config bus probing 



The vexpress-config initialization is dependent on the vexpress-syscfg
driver probing. As vexpress-config was not a driver, deferred probe
could not be used and instead initcall ordering was relied upon. This is
fragile and doesn't work for modules.

Let's move the config bus init into the vexpress-syscfg probe. This
eliminates the initcall ordering requirement and the need to create a
struct device and the "vexpress-config" class.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Acked-by: default avatarLiviu Dudau <liviu.dudau@arm.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent d06cfe3f

drivers/bus/vexpress-config.c

+21 −97
Original line number Diff line number Diff line
@@ -56,7 +56,6 @@ struct vexpress_config_bridge { 




static DEFINE_MUTEX(vexpress_config_mutex);

static struct class *vexpress_config_class;

static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
@@ -121,9 +120,6 @@ struct regmap *devm_regmap_init_vexpress_config(struct device *dev) 
	struct regmap *regmap;

	struct regmap **res;



	if (WARN_ON(dev->parent->class != vexpress_config_class))

		return ERR_PTR(-ENODEV);



	bridge = dev_get_drvdata(dev->parent);

	if (WARN_ON(!bridge))

		return ERR_PTR(-EINVAL);
@@ -146,94 +142,6 @@ struct regmap *devm_regmap_init_vexpress_config(struct device *dev) 
}

EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);



static struct device *vexpress_config_bridge_register(struct device *parent,

		struct vexpress_config_bridge_ops *ops, void *context)

{

	struct device *dev;

	struct vexpress_config_bridge *bridge;



	if (!vexpress_config_class) {

		vexpress_config_class = class_create(THIS_MODULE,

				"vexpress-config");

		if (IS_ERR(vexpress_config_class))

			return (void *)vexpress_config_class;

	}



	dev = device_create(vexpress_config_class, parent, 0,

			NULL, "%s.bridge", dev_name(parent));



	if (IS_ERR(dev))

		return dev;



	bridge = devm_kmalloc(dev, sizeof(*bridge), GFP_KERNEL);

	if (!bridge) {

		put_device(dev);

		device_unregister(dev);

		return ERR_PTR(-ENOMEM);

	}

	bridge->ops = ops;

	bridge->context = context;



	dev_set_drvdata(dev, bridge);



	dev_dbg(parent, "Registered bridge '%s', parent node %p\n",

			dev_name(dev), parent->of_node);



	return dev;

}





static int vexpress_config_node_match(struct device *dev, const void *data)

{

	const struct device_node *node = data;



	dev_dbg(dev, "Parent node %p, looking for %p\n",

			dev->parent->of_node, node);



	return dev->parent->of_node == node;

}



static int vexpress_config_populate(struct device_node *node)

{

	struct device_node *bridge;

	struct device *parent;

	int ret;



	bridge = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);

	if (!bridge)

		return -EINVAL;



	parent = class_find_device(vexpress_config_class, NULL, bridge,

			vexpress_config_node_match);

	of_node_put(bridge);

	if (WARN_ON(!parent))

		return -ENODEV;



	ret = of_platform_populate(node, NULL, NULL, parent);



	put_device(parent);



	return ret;

}



static int __init vexpress_config_init(void)

{

	int err = 0;

	struct device_node *node;



	/* Need the config devices early, before the "normal" devices... */

	for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {

		err = vexpress_config_populate(node);

		if (err) {

			of_node_put(node);

			break;

		}

	}



	return err;

}

postcore_initcall(vexpress_config_init);



static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,

		int index, bool write, u32 *data)

{
@@ -430,7 +338,8 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) 
{

	struct vexpress_syscfg *syscfg;

	struct resource *res;

	struct device *bridge;

	struct vexpress_config_bridge *bridge;

	struct device_node *node;



	syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);

	if (!syscfg)
@@ -443,11 +352,26 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) 
	if (IS_ERR(syscfg->base))

		return PTR_ERR(syscfg->base);



	/* Must use dev.parent (MFD), as that's where DT phandle points at... */

	bridge = vexpress_config_bridge_register(pdev->dev.parent,

			&vexpress_syscfg_bridge_ops, syscfg);

	bridge = devm_kmalloc(&pdev->dev, sizeof(*bridge), GFP_KERNEL);

	if (!bridge)

		return -ENOMEM;



	bridge->ops = &vexpress_syscfg_bridge_ops;

	bridge->context = syscfg;



	return PTR_ERR_OR_ZERO(bridge);

	dev_set_drvdata(&pdev->dev, bridge);



	for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {

		struct device_node *bridge_np;



		bridge_np = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);

		if (bridge_np != pdev->dev.parent->of_node)

			continue;



		of_platform_populate(node, NULL, NULL, &pdev->dev);

	}



	return 0;

}



static const struct platform_device_id vexpress_syscfg_id_table[] = {

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