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>
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 48dd417..474bada 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -14,6 +14,7 @@
obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o
obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o
obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
+obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o
obj-$(CONFIG_QCOM_SCM) += qcom_scm.o
obj-$(CONFIG_QCOM_SCM_64) += qcom_scm-64.o
obj-$(CONFIG_QCOM_SCM_32) += qcom_scm-32.o