Commit 114294d2 authored by Charles Keepax's avatar Charles Keepax Committed by Lee Jones
Browse files

mfd: mfd-core: Add mechanism for removal of a subset of children 

Currently, the only way to remove MFD children is with a call to
mfd_remove_devices, which will remove all the children. Under
some circumstances it is useful to remove only a subset of the
child devices. For example if some additional clean up is required
between removal of certain child devices.

To accomplish this a level field is added to mfd_cell, the normal
mfd_remove_devices is modified to not remove devices that are set
to a higher level and a corresponding mfd_remove_devices_late
function is added to remove those children.

See further discussion at:
https://lore.kernel.org/lkml/20200616075834.GF2608702@dell/



Suggested-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 4ee1d9dc

drivers/mfd/mfd-core.c

+15 −1
Original line number Diff line number Diff line
@@ -356,6 +356,7 @@ static int mfd_remove_devices_fn(struct device *dev, void *data) 
{

	struct platform_device *pdev;

	const struct mfd_cell *cell;

	int *level = data;



	if (dev->type != &mfd_dev_type)

		return 0;
@@ -363,6 +364,9 @@ static int mfd_remove_devices_fn(struct device *dev, void *data) 
	pdev = to_platform_device(dev);

	cell = mfd_get_cell(pdev);



	if (level && cell->level > *level)

		return 0;



	regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,

					       cell->num_parent_supplies);
@@ -372,9 +376,19 @@ static int mfd_remove_devices_fn(struct device *dev, void *data) 
	return 0;

}



void mfd_remove_devices_late(struct device *parent)

{

	int level = MFD_DEP_LEVEL_HIGH;



	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);

}

EXPORT_SYMBOL(mfd_remove_devices_late);



void mfd_remove_devices(struct device *parent)

{

	device_for_each_child_reverse(parent, NULL, mfd_remove_devices_fn);

	int level = MFD_DEP_LEVEL_NORMAL;



	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);

}

EXPORT_SYMBOL(mfd_remove_devices);

include/linux/mfd/core.h

+5 −0
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ 
#define MFD_CELL_NAME(_name) \

	MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, 0, false, NULL)



#define MFD_DEP_LEVEL_NORMAL 0

#define MFD_DEP_LEVEL_HIGH 1



struct irq_domain;

struct property_entry;
@@ -63,6 +66,7 @@ struct mfd_cell_acpi_match { 
struct mfd_cell {

	const char		*name;

	int			id;

	int			level;



	int			(*enable)(struct platform_device *dev);

	int			(*disable)(struct platform_device *dev);
@@ -150,6 +154,7 @@ static inline int mfd_add_hotplug_devices(struct device *parent, 
}



extern void mfd_remove_devices(struct device *parent);

extern void mfd_remove_devices_late(struct device *parent);



extern int devm_mfd_add_devices(struct device *dev, int id,

				const struct mfd_cell *cells, int n_devs,

CRA Git | Maintained and supported by SUSTech CRA and CCSE