path: root/arch/powerpc/boot
diff options
authorTimur Tabi <timur@freescale.com>2012-07-05 10:08:28 -0500
committerKumar Gala <galak@kernel.crashing.org>2012-07-10 07:07:21 -0500
commit6bd825f02966be8ba544047cab313d6032c23819 (patch)
tree8e294c6f66a1ac5ed02b41dab5e04fbed017a6e1 /arch/powerpc/boot
parentaeccf8983e002557aa7728c0678c1dd6d9027193 (diff)
powerpc/85xx: use the BRx registers to enable indirect mode on the P1022DS
In order to enable the DIU video controller on the P1022DS, the FPGA needs to be switched to "indirect mode", where the localbus is disabled and the FPGA is accessed via writes to localbus chip select signals CS0 and CS1. To obtain the address of CS0 and CS1, the platform driver uses an "indirect pixis mode" device tree node. This node assumes that the localbus 'ranges' property is sorted in chip-select order. That is, reg value 0 maps to CS0, reg value 1 maps to CS1, etc. This is how the 'ranges' property is supposed to be arranged. Unfortunately, the 'ranges' property is often mis-arranged, and not just on the P1022DS. Linux normally does not care, since it does not program the localbus. But the indirect-mode code on the P1022DS does care. The "proper" fix is to have U-Boot fix the 'ranges' property, but this would be too cumbersome. The names and 'reg' properties of all the localbus devices would also need to be updated, and determining which localbus device maps to which chip select is board-specific. Instead, we determine the CS0/CS1 base addresses the same way that U-boot does -- by reading the BRx registers directly and mapping them to physical addresses. This code is simpler and more reliable, and it does not require a U-boot or device tree change. Since the indirect pixis device tree node is no longer needed, the node is deleted from the DTS. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/boot')
1 files changed, 0 insertions, 16 deletions
diff --git a/arch/powerpc/boot/dts/p1022ds.dtsi b/arch/powerpc/boot/dts/p1022ds.dtsi
index 28c36377f9b..c3344b04d8f 100644
--- a/arch/powerpc/boot/dts/p1022ds.dtsi
+++ b/arch/powerpc/boot/dts/p1022ds.dtsi
@@ -33,22 +33,6 @@
&board_lbc {
- /*
- * This node is used to access the pixis via "indirect" mode,
- * which is done by writing the pixis register index to chip
- * select 0 and the value to/from chip select 1. Indirect
- * mode is the only way to access the pixis when DIU video
- * is enabled. Note that this assumes that the first column
- * of the 'ranges' property above is the chip select number.
- */
- board-control@0,0 {
- compatible = "fsl,p1022ds-indirect-pixis";
- reg = <0x0 0x0 1 /* CS0 */
- 0x1 0x0 1>; /* CS1 */
- interrupt-parent = <&mpic>;
- interrupts = <8 0 0 0>;
- };
nor@0,0 {
#address-cells = <1>;
#size-cells = <1>;