arm: a37xx: Remap IO space to bus address 0x0

Remap PCI I/O space to the bus address 0x0 in the Armada 37xx device-tree
in order to support legacy I/O port based cards which have hardcoded I/O
ports in low address space.

Some legacy PCI I/O based cards do not support 32-bit I/O addressing.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/arch/arm/dts/armada-3720-turris-mox.dts b/arch/arm/dts/armada-3720-turris-mox.dts
index 1fc4a30..595b4b5 100644 (file)
--- a/arch/arm/dts/armada-3720-turris-mox.dts
+++ b/arch/arm/dts/armada-3720-turris-mox.dts
@@ -139,7 +139,9 @@
        /*
         * U-Boot port for Turris Mox has a bug which always expects that "ranges" DT property
         * contains exactly 2 ranges with 3 (child) address cells, 2 (parent) address cells and
-        * 2 size cells and also expects that the second range starts at 16 MB offset. If these
+        * 2 size cells and also expects that the second range starts at 16 MB offset. Also it
+        * expects that first range uses same address for PCI (child) and CPU (parent) cells (so
+        * no remapping) and that this address is the lowest from all specified ranges. If these
         * conditions are not met then U-Boot crashes during loading kernel DTB file. PCIe address
         * space is 128 MB long, so the best split between MEM and IO is to use fixed 16 MB window
         * for IO and the rest 112 MB (64+32+16) for MEM. Controller supports 32-bit IO mapping.
@@ -148,6 +150,9 @@
         * https://source.denx.de/u-boot/u-boot/-/commit/cb2ddb291ee6fcbddd6d8f4ff49089dfe580f5d7
         * https://source.denx.de/u-boot/u-boot/-/commit/c64ac3b3185aeb3846297ad7391fc6df8ecd73bf
         * https://source.denx.de/u-boot/u-boot/-/commit/4a82fca8e330157081fc132a591ebd99ba02ee33
+        * Bug related to requirement of same child and parent addresses for first range is fixed
+        * in U-Boot version 2022.04 by following commit:
+        * https://source.denx.de/u-boot/u-boot/-/commit/1fd54253bca7d43d046bba4853fe5fafd034bc17
         */
        #address-cells = <3>;
        #size-cells = <2>;

diff --git a/arch/arm/dts/armada-37xx.dtsi b/arch/arm/dts/armada-37xx.dtsi
index 9fa6457..0bb4f60 100644 (file)
--- a/arch/arm/dts/armada-37xx.dtsi
+++ b/arch/arm/dts/armada-37xx.dtsi
@@ -499,7 +499,7 @@
                         * (totaling 127 MiB) for MEM.
                         */
                        ranges = <0x82000000 0 0xe8000000   0 0xe8000000   0 0x07f00000   /* Port 0 MEM */
-                                 0x81000000 0 0xeff00000   0 0xeff00000   0 0x00100000>; /* Port 0 IO*/
+                                 0x81000000 0 0x00000000   0 0xeff00000   0 0x00100000>; /* Port 0 IO */
                        interrupt-map-mask = <0 0 0 7>;
                        interrupt-map = <0 0 0 1 &pcie_intc 0>,
                                        <0 0 0 2 &pcie_intc 1>,