[PATCH 7/7] [POWERPC] Xilinx: Update booting-without-of.
Grant Likely
grant.likely at secretlab.ca
Tue Dec 18 02:19:50 EST 2007
On 12/13/07, Stephen Neuendorffer <stephen.neuendorffer at xilinx.com> wrote:
> This now better describes what the UBoot device tree generator actually does. In particular:
>
> 1) Nodes have a label derived from the device name, and a node name
> derived from the device type.
> 2) Usage of compound nodes (representing more than one device in the same IP) which actually works. This requires having a valid compatible node, and all the other things that a bus normally has. I've chosen 'xlnx,compound' as the bus name to describe these compound nodes.
> 3) Uartlite requires a port-number property for the console to work.
>
> In addition, I've clarified some of the language relating to how mhs
> nodes should be represent in the device tree.
Thanks for the updates. Comments below.
> ---
> Documentation/powerpc/booting-without-of.txt | 61 +++++++++++++++-----------
> 1 files changed, 36 insertions(+), 25 deletions(-)
>
> diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
> index e9a3cb1..5e2b85a 100644
> --- a/Documentation/powerpc/booting-without-of.txt
> +++ b/Documentation/powerpc/booting-without-of.txt
> @@ -2276,7 +2276,7 @@ platforms are moved over to use the flattened-device-tree model.
> properties of the device node. In general, device nodes for IP-cores
> will take the following form:
>
> - (name)@(base-address) {
> + (name): (ip-core-name)@(base-address) {
(name): (generic-name)@(base-address) {
> compatible = "xlnx,(ip-core-name)-(HW_VER)"
> [, (list of compatible devices), ...];
> reg = <(baseaddr) (size)>;
> @@ -2294,9 +2294,9 @@ platforms are moved over to use the flattened-device-tree model.
> dropped from the parameter name, the name is converted
> to lowercase and all underscore '_' characters are
> converted to dashes '-'.
> - (baseaddr): the C_BASEADDR parameter.
> + (baseaddr): the baseaddr parameter value (often named C_BASEADDR).
> (HW_VER): from the HW_VER parameter.
> - (size): equals C_HIGHADDR - C_BASEADDR + 1
> + (size): the address range size (often C_HIGHADDR - C_BASEADDR + 1).
Ah, yes. Good clarification.
>
> Typically, the compatible list will include the exact IP core version
> followed by an older IP core version which implements the same
> @@ -2326,12 +2326,13 @@ platforms are moved over to use the flattened-device-tree model.
>
> becomes the following device tree node:
>
> - opb-uartlite-0 at ec100000 {
> + opb_uartlite_0: serial at ec100000 {
> device_type = "serial";
> compatible = "xlnx,opb-uartlite-1.00.b";
> reg = <ec100000 10000>;
> - interrupt-parent = <&opb-intc>;
> + interrupt-parent = <&opb_intc_0>;
> interrupts = <1 0>; // got this from the opb_intc parameters
> + port-number = <0>;
> current-speed = <d#115200>; // standard serial device prop
> clock-frequency = <d#50000000>; // standard serial device prop
> xlnx,data-bits = <8>;
> @@ -2339,16 +2340,19 @@ platforms are moved over to use the flattened-device-tree model.
> xlnx,use-parity = <0>;
> };
>
> - Some IP cores actually implement 2 or more logical devices. In this case,
> - the device should still describe the whole IP core with a single node
> - and add a child node for each logical device. The ranges property can
> - be used to translate from parent IP-core to the registers of each device.
> - (Note: this makes the assumption that both logical devices have the same
> - bus binding. If this is not true, then separate nodes should be used for
> - each logical device). The 'cell-index' property can be used to enumerate
> - logical devices within an IP core. For example, the following is the
> - system.mhs entry for the dual ps2 controller found on the ml403 reference
> - design.
> + Some IP cores actually implement 2 or more logical devices. In
> + this case, the device should still describe the whole IP core with
> + a single node and add a child node for each logical device. The
> + ranges property can be used to translate from parent IP-core to the
> + registers of each device. In addition, the parent node should be
> + compatible with the bus type 'xlnx,compound', and should contain
> + #address-cells and #size-cells, as with any other bus. (Note: this
> + makes the assumption that both logical devices have the same bus
> + binding. If this is not true, then separate nodes should be used
> + for each logical device). The 'cell-index' property can be used to
> + enumerate logical devices within an IP core. For example, the
> + following is the system.mhs entry for the dual ps2 controller found
> + on the ml403 reference design.
>
> BEGIN opb_ps2_dual_ref
> PARAMETER INSTANCE = opb_ps2_dual_ref_0
> @@ -2370,21 +2374,24 @@ platforms are moved over to use the flattened-device-tree model.
>
> It would result in the following device tree nodes:
>
> - opb_ps2_dual_ref_0 at a9000000 {
> + opb_ps2_dual_ref_0: opb-ps2-dual-ref at a9000000 {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "xlnx,compound";
> ranges = <0 a9000000 2000>;
> // If this device had extra parameters, then they would
> // go here.
> - ps2 at 0 {
> + opb-ps2-dual-ref at 0 {
According to the generic names recommendation, this should be either
"keyboard at 0" or "mouse at 0", but of course the two interfaces are
identical and EDK doesn't have any information about how they are
used. Perhaps the node name should be: "ps2 at 0". David, thoughts?
> compatible = "xlnx,opb-ps2-dual-ref-1.00.a";
> reg = <0 40>;
> - interrupt-parent = <&opb-intc>;
> + interrupt-parent = <&opb_intc_0>;
> interrupts = <3 0>;
> cell-index = <0>;
> };
> - ps2 at 1000 {
> + opb-ps2-dual-ref at 1000 {
> compatible = "xlnx,opb-ps2-dual-ref-1.00.a";
> reg = <1000 40>;
> - interrupt-parent = <&opb-intc>;
> + interrupt-parent = <&opb_intc_0>;
> interrupts = <3 0>;
> cell-index = <0>;
> };
> @@ -2447,17 +2454,18 @@ platforms are moved over to use the flattened-device-tree model.
>
> Gives this device tree (some properties removed for clarity):
>
> - plb-v34-0 {
> + plb_v34 {
Steve, when I wrote this I was lazy and I didn't add the bus address.
However, if we don't have the base address I think we'll end up with
name collisions (especially in the MPMC case). So, based on generic
names convention, this should probably simply be "plb@<baseaddr>".
> #address-cells = <1>;
> #size-cells = <1>;
> + compatible = "xlnx,plb-v34-1.02.a";
> device_type = "ibm,plb";
> ranges; // 1:1 translation
>
> - plb-bram-if-cntrl-0 at ffff0000 {
> + plb_bram_if_cntrl_0: plb-bram-if-cntrl at ffff0000 {
Node name should probably just be "bram at ffff0000" here.
> reg = <ffff0000 10000>;
> }
>
> - opb-v20-0 {
> + opb_v20 {
opb@<baseaddr>
> #address-cells = <1>;
> #size-cells = <1>;
> ranges = <20000000 20000000 20000000
> @@ -2465,11 +2473,11 @@ platforms are moved over to use the flattened-device-tree model.
> 80000000 80000000 40000000
> c0000000 c0000000 20000000>;
>
> - opb-uart16550-0 at a0000000 {
> + opb_uart16550_0: opb-uart16550 at a0000000 {
serial at a0000000
> reg = <a00000000 2000>;
> };
>
> - opb-intc-0 at d1000fc0 {
> + opb_intc_0: opb-intc at d1000fc0 {
interrupt-controller at d1000fc0
> reg = <d1000fc0 20>;
> };
> };
> @@ -2513,6 +2521,9 @@ platforms are moved over to use the flattened-device-tree model.
>
> Requred properties:
> - current-speed : Baud rate of uartlite
> + Optional properties:
> + - port-number : unique ordinal index of the device. This
> + property is required for a console on uartlite.
And has already been discussed, drop the port-number property. I'll
rework the uartlite driver to use aliases instead.
Cheers,
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely at secretlab.ca
(403) 399-0195
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