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: Lee Jones <lee.jo...@linaro.org> Signed-off-by: Charles Keepax <ckee...@opensource.cirrus.com> --- Changes since v2: - Removed old tag system and now just have 2 levels, one removed by new mfd_remove_devices_late Thanks, Charles drivers/mfd/mfd-core.c | 16 +++++++++++++++- include/linux/mfd/core.h | 5 +++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index f5a73af60dd40..d1602a87db29b 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -287,6 +287,7 @@ 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; @@ -294,6 +295,9 @@ 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); @@ -301,9 +305,19 @@ 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); diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h index 7e5ac3c00891a..1ca2048eba22b 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -41,6 +41,9 @@ #define MFD_CELL_NAME(_name) \ MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, NULL) \ +#define MFD_DEP_LEVEL_NORMAL 0 +#define MFD_DEP_LEVEL_HIGH 1 + struct irq_domain; struct property_entry; @@ -58,6 +61,7 @@ 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); @@ -135,6 +139,7 @@ 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, -- 2.11.0
