kernel/linux.git/drivers/mfd/mfd-core.c, branch v6.6.131

mfd: core: Add locking around 'mfd_of_node_list'

2026-03-04T12:21:11+00:00

[ Upstream commit 20117c92bcf9c11afd64d7481d8f94fdf410726e ] Manipulating a list in the kernel isn't safe without some sort of mutual exclusion. Add a mutex any time we access / modify 'mfd_of_node_list' to prevent possible crashes. Cc: stable@vger.kernel.org Fixes: 466a62d7642f ("mfd: core: Make a best effort attempt to match devices with the correct of_nodes") Signed-off-by: Douglas Anderson Link: https://patch.msgid.link/20251210113002.1.I6ceaca2cfb7eb25737012b166671f516696be4fd@changeid Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

mfd: core: Ensure disabled devices are skipped without aborting

2023-11-20T10:59:24+00:00

[ Upstream commit 7ba7bdef4d14e3722e2842da3b48cbadb73e52d6 ] The loop searching for a matching device based on its compatible string is aborted when a matching disabled device is found. This abort prevents to add devices as soon as one disabled device is found. Continue searching for an other device instead of aborting on the first disabled one fixes the issue. Fixes: 22380b65dc70 ("mfd: mfd-core: Ensure disabled devices are ignored without error") Signed-off-by: Herve Codina Reviewed-by: Christophe Leroy Signed-off-by: Christophe Leroy Link: https://lore.kernel.org/r/528425d6472176bb1d02d79596b51f8c28a551cc.1692376361.git.christophe.leroy@csgroup.eu Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

mfd: core: Use of_property_read_reg() to parse "reg"

2023-06-15T15:22:54+00:00

Use the recently added of_property_read_reg() helper to get the untranslated "reg" address value. Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20230609183159.1766429-1-robh@kernel.org Signed-off-by: Lee Jones

mfd: core: Remove .enable() and .disable() callbacks

2023-04-26T10:40:29+00:00

With commit dd77f5fa97d3 ("mfd: Remove toshiba tmio drivers") the last mfd driver that implements these callbacks is gone and since commit 652719b1003a ("w1: remove ds1wm driver") the last user is gone. The corresponding functions mfd_cell_enable() and mfd_cell_disable() are also unused (since commit 0ca222c81977 ("leds: Remove asic3 driver")). Signed-off-by: Uwe Kleine-König Acked-by: Arnd Bergmann Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20230308091257.2404932-1-u.kleine-koenig@pengutronix.de

mfd: Move from strlcpy with unused retval to strscpy

2022-09-28T15:17:39+00:00

Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20220818210030.7012-1-wsa+renesas@sang-engineering.com

mfd: core: Delete corresponding OF node entries from list on MFD removal

2022-09-28T15:09:50+00:00

When we consider MFD which implements hotplug (e.g. USB hotplug driver based on product and vendor IDs) functionality it turns out that its sub-devices are correctly matched with corresponding device tree nodes only at the first time. When physical device reboots or is replugged (and MFD driver is disconnected and probed back again) all sub-devices fails in mfd_add_device() with error 'Failed to locate of_node'. The reason of that behavior is that when any MFD sub-device is created for the first time (and matched with device tree node) it is added to the mfd_of_node_list. It looks like this list is never cleaned even if devices added there are intentionally removed from the system. So when MFD device is replugged and all sub-devices are matched with their device tree nodes again they fail as matched nodes already exist in mfd_of_node_list. In other words current implementation does not support MFD with hotplug feature. This commit extends MFD core for hotplugging support by removing appropriate OF node entry from mfd_of_node_list when corresponding device is removed from the system. Thanks to that when device is added once again it can be matched with its device tree node successfully. Signed-off-by: Michal Oleszczyk Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20220809060336.31892-1-m.oleszczyk@grinn-global.com

mfd: core: Use acpi_dev_for_each_child()

2022-06-27T11:22:06+00:00

Instead of walking the list of children of an ACPI device directly, use acpi_dev_for_each_child() to carry out an action for all of the given ACPI device's children. This will help to eliminate the children list head from struct acpi_device as it is redundant and it is used in questionable ways in some places (in particular, locking is needed for walking the list pointed to it safely, but it is often missing). Signed-off-by: Rafael J. Wysocki Reviewed-by: Andy Shevchenko Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/2726954.BEx9A2HvPv@kreacher

mfd: core: Add missing of_node_put for loop iteration

2021-11-05T14:40:25+00:00

Early exits from for_each_child_of_node() should decrement the node reference counter. Reported by Coccinelle: drivers/mfd/mfd-core.c:197:2-24: WARNING: Function "for_each_child_of_node" should have of_node_put() before goto around lines 209. Fixes: c94bb233a9fe ("mfd: Make MFD core code Device Tree and IRQ domain aware") Signed-off-by: Krzysztof Kozlowski Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20210528115126.18370-1-krzysztof.kozlowski@canonical.com

mfd: Remove software node conditionally and locate at right place

2021-06-02T09:50:00+00:00

Currently the software node is removed in error case and at ->remove() stage unconditionally, that ruins the symmetry. Besides, in some cases, when mfd_add_device() fails, the device_remove_software_node() call may lead to NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 00000000 ... EIP: strlen+0x12/0x20 ... kernfs_name_hash+0x13/0x70 kernfs_find_ns+0x32/0xc0 kernfs_remove_by_name_ns+0x2a/0x90 sysfs_remove_link+0x16/0x30 software_node_notify.cold+0x34/0x6b device_remove_software_node+0x5a/0x90 mfd_add_device.cold+0x30a/0x427 Fix all these by guarding device_remove_software_node() with a conditional and locating it at the right place. Fixes: 42e59982917a ("mfd: core: Add support for software nodes") Signed-off-by: Andy Shevchenko Signed-off-by: Lee Jones

mfd: core: Use acpi_find_child_device() for child devices lookup

2021-04-14T15:06:36+00:00

Use acpi_find_child_device() for child devices lookup in mfd_acpi_add_device() instead of open coded approach. No functional change intended. While at it, amend a note comment, since usage of _ADR is found on other platforms and tables than Intel Galileo Gen 2, in particular USB wired devices are using it, according to Microsoft specifications for embedded platforms. Signed-off-by: Andy Shevchenko Signed-off-by: Lee Jones