From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Bresticker Subject: [PATCH V3 3/5] MIPS: Document Pistachio boot protocol and device-tree bindings Date: Mon, 16 Mar 2015 14:43:09 -0700 Message-ID: <1426542191-6883-4-git-send-email-abrestic@chromium.org> References: <1426542191-6883-1-git-send-email-abrestic@chromium.org> Return-path: In-Reply-To: <1426542191-6883-1-git-send-email-abrestic@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Ralf Baechle Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, Andrew Bresticker , Ezequiel Garcia , James Hartley , James Hogan , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala List-Id: devicetree@vger.kernel.org The Pistachio SoC boots only with device-tree. Document the required properties and nodes as well as the boot protocol between the bootlaoder and the kernel. Signed-off-by: Andrew Bresticker Cc: Rob Herring Cc: Pawel Moll Cc: Mark Rutland Cc: Ian Campbell Cc: Kumar Gala --- No changes from v2. Changes from v1: - switched to MIPS UHI hand-off protocol --- .../devicetree/bindings/mips/img/pistachio.txt | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/mips/img/pistachio.txt diff --git a/Documentation/devicetree/bindings/mips/img/pistachio.txt b/Documentation/devicetree/bindings/mips/img/pistachio.txt new file mode 100644 index 0000000..a736d88 --- /dev/null +++ b/Documentation/devicetree/bindings/mips/img/pistachio.txt @@ -0,0 +1,42 @@ +Imagination Pistachio SoC +========================= + +Required properties: +-------------------- + - compatible: Must include "img,pistachio". + +CPU nodes: +---------- +A "cpus" node is required. Required properties: + - #address-cells: Must be 1. + - #size-cells: Must be 0. +A CPU sub-node is also required for at least CPU 0. Since the topology may +be probed via CPS, it is not necessary to specify secondary CPUs. Required +propertis: + - device_type: Must be "cpu". + - compatible: Must be "mti,interaptiv". + - reg: CPU number. + - clocks: Must include the CPU clock. See ../../clock/clock-bindings.txt for + details on clock bindings. +Example: + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu0: cpu@0 { + device_type = "cpu"; + compatible = "mti,interaptiv"; + reg = <0>; + clocks = <&clk_core CLK_MIPS>; + }; + }; + + +Boot protocol: +-------------- +In accordance with the MIPS UHI specification[1], the bootloader must pass the +following arguments to the kernel: + - $a0: -2. + - $a1: KSEG0 address of the flattened device-tree blob. + +[1] http://prplfoundation.org/wiki/MIPS_documentation -- 2.2.0.rc0.207.ga3a616c