firmware: introduce sysfs driver for QEMU's fw_cfg device
authorGabriel Somlo <somlo@cmu.edu>
Thu, 28 Jan 2016 14:23:11 +0000 (09:23 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 10 Feb 2016 01:37:39 +0000 (17:37 -0800)
commit75f3e8e47f381074801d0034874d20c638d9e3d9
treeb6d6e20113c38b04c126747144a162055f7e7a69
parent2fe829aca9d7bed5fd6b49c6a1452e5e486b6cc3
firmware: introduce sysfs driver for QEMU's fw_cfg device

Make fw_cfg entries of type "file" available via sysfs. Entries
are listed under /sys/firmware/qemu_fw_cfg/by_key, in folders
named after each entry's selector key. Filename, selector value,
and size read-only attributes are included for each entry. Also,
a "raw" attribute allows retrieval of the full binary content of
each entry.

The fw_cfg device can be instantiated automatically from ACPI or
the Device Tree, or manually by using a kernel module (or command
line) parameter, with a syntax outlined in the documentation file.

Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/ABI/testing/sysfs-firmware-qemu_fw_cfg [new file with mode: 0644]
drivers/firmware/Kconfig
drivers/firmware/Makefile
drivers/firmware/qemu_fw_cfg.c [new file with mode: 0644]