linux/drivers/base
Hans de Goede e4c2c0ff00 firmware: Add new platform fallback mechanism and firmware_request_platform()
In some cases the platform's main firmware (e.g. the UEFI fw) may contain
an embedded copy of device firmware which needs to be (re)loaded into the
peripheral. Normally such firmware would be part of linux-firmware, but in
some cases this is not feasible, for 2 reasons:

1) The firmware is customized for a specific use-case of the chipset / use
with a specific hardware model, so we cannot have a single firmware file
for the chipset. E.g. touchscreen controller firmwares are compiled
specifically for the hardware model they are used with, as they are
calibrated for a specific model digitizer.

2) Despite repeated attempts we have failed to get permission to
redistribute the firmware. This is especially a problem with customized
firmwares, these get created by the chip vendor for a specific ODM and the
copyright may partially belong with the ODM, so the chip vendor cannot
give a blanket permission to distribute these.

This commit adds a new platform fallback mechanism to the firmware loader
which will try to lookup a device fw copy embedded in the platform's main
firmware if direct filesystem lookup fails.

Drivers which need such embedded fw copies can enable this fallback
mechanism by using the new firmware_request_platform() function.

Note that for now this is only supported on EFI platforms and even on
these platforms firmware_fallback_platform() only works if
CONFIG_EFI_EMBEDDED_FIRMWARE is enabled (this gets selected by drivers
which need this), in all other cases firmware_fallback_platform() simply
always returns -ENOENT.

Reported-by: Dave Olsthoorn <dave@bewaar.me>
Suggested-by: Peter Jones <pjones@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200115163554.101315-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-20 14:54:04 +01:00
..
firmware_loader firmware: Add new platform fallback mechanism and firmware_request_platform() 2020-03-20 14:54:04 +01:00
power Revert "drivers: base: power: wakeup.c: Use built-in RCU list checking" 2020-03-19 10:20:27 +01:00
regmap regmap: fix writes to non incrementing registers 2020-01-21 17:16:26 +00:00
test Driver core changes for 5.6-rc1 2020-01-29 10:18:20 -08:00
arch_topology.c arch_topology: Fix putting invalid cpu clk 2020-03-18 11:41:54 +01:00
attribute_container.c scsi: drivers: base: Support atomic version of attribute_container_device_trigger 2020-01-15 22:55:36 -05:00
base.h device.h: move devtmpfs prototypes out of the file 2019-12-16 10:10:18 +01:00
bus.c device.h: move 'struct bus' stuff out to device/bus.h 2019-12-16 10:11:12 +01:00
cacheinfo.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
class.c device.h: move 'struct class' stuff out to device/class.h 2019-12-16 10:11:14 +01:00
component.c component: allow missing unbind callback 2020-03-18 14:13:33 +01:00
container.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
core.c Merge 5.6-rc5 into driver-core-next 2020-03-09 08:41:53 +01:00
cpu.c drivers/base/cpu: Simplify s*nprintf() usages 2020-03-11 09:08:44 +01:00
dd.c driver core: Rename deferred_probe_timeout and make it global 2020-03-04 18:11:44 +01:00
devcon.c Merge generic_lookup_helpers into usb-next 2019-09-03 17:11:07 +02:00
devcoredump.c devcoredump: fix typo in comment 2019-08-15 17:38:11 +02:00
devres.c drivers/base/devres: introduce devm_release_action() 2019-06-13 17:34:56 -10:00
devtmpfs.c Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
driver.c device.h: move 'struct driver' stuff out to device/driver.h 2019-12-16 10:11:16 +01:00
firmware.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
hypervisor.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
init.c base: fix order of OF initialization 2018-07-07 17:54:29 +02:00
isa.c Merge 4.15-rc3 into driver-core-next 2017-12-11 08:50:05 +01:00
Kconfig kunit: building kunit as a module breaks allmodconfig 2020-01-10 14:36:37 -07:00
Makefile drivers: base: Introducing software nodes to the firmware node framework 2018-11-26 18:19:11 +01:00
map.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
memory.c mm/memory_hotplug: drop valid_start/valid_end from test_pages_in_a_zone() 2020-02-04 03:05:23 +00:00
module.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
node.c mm/vmstat: add helpers to get vmstat item names for each enum type 2019-12-04 19:44:11 -08:00
pinctrl.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
platform-msi.c platform-msi: Free descriptors in platform_msi_domain_free() 2018-12-13 09:35:31 +00:00
platform.c driver core: platform: fix u32 greater or equal to zero comparison 2020-01-22 15:27:11 +01:00
property.c device property: Add a function to obtain a node's prefix 2019-10-11 11:26:55 +02:00
soc.c base: soc: Handle custom soc information sysfs entries 2019-10-10 14:35:32 +02:00
swnode.c Revert "software node: Simplify software_node_release() function" 2020-03-04 22:31:44 +01:00
syscore.c treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively 2019-04-09 14:19:06 +02:00
topology.c topology: Create core_cpus and die_cpus sysfs attributes 2019-05-23 10:08:34 +02:00
transport_class.c scsi: drivers: base: Propagate errors through the transport component 2020-01-15 22:55:37 -05:00