drivers: add fpga bridge framework

Import the fpga bridge framework from linux v4.10-rc2.

Description from the initial commit adding this to linux:
21aeda950c5f84a8351b862816d832120b217a9b

    fpga: add fpga bridge framework

    This framework adds API functions for enabling/
    disabling FPGA bridges under kernel control.

    This allows the Linux kernel to disable FPGA bridges
    during FPGA reprogramming and to enable FPGA bridges
    when FPGA reprogramming is done.  This framework is
    be manufacturer-agnostic, allowing it to be used in
    interfaces that use the FPGA Manager Framework to
    reprogram FPGA's.

    The functions are:
    * of_fpga_bridge_get
    * fpga_bridge_put
       Get/put an exclusive reference to a FPGA bridge.

    * fpga_bridge_enable
    * fpga_bridge_disable
       Enable/Disable traffic through a bridge.

    * fpga_bridge_register
    * fpga_bridge_unregister
       Register/unregister a device-specific low level FPGA
       Bridge driver.

    Get an exclusive reference to a bridge and add it to a list:
    * fpga_bridge_get_to_list

    To enable/disable/put a set of bridges that are on a list:
    * fpga_bridges_enable
    * fpga_bridges_disable
    * fpga_bridges_put

    Signed-off-by: Alan Tull <atull@opensource.altera.com>

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Link: https://lore.barebox.org/20210616063246.14900-2-s.trumtrar@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 787d366933..670e0a9f4c 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -37,6 +37,7 @@ source "drivers/reset/Kconfig"
 source "drivers/pci/Kconfig"
 source "drivers/rtc/Kconfig"
 source "drivers/firmware/Kconfig"
+source "drivers/fpga/Kconfig"
 source "drivers/phy/Kconfig"
 source "drivers/crypto/Kconfig"
 source "drivers/memory/Kconfig"