From mboxrd@z Thu Jan 1 00:00:00 1970 From: f.fainelli@gmail.com (Florian Fainelli) Date: Tue, 15 Sep 2015 11:14:58 -0700 Subject: [PATCH v2 1/3] Documentation: bindings: brcmstb: Document write-pairing In-Reply-To: <1442340900-15320-1-git-send-email-f.fainelli@gmail.com> References: <1442340900-15320-1-git-send-email-f.fainelli@gmail.com> Message-ID: <1442340900-15320-2-git-send-email-f.fainelli@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Document the hif-cpubiuctrl node a bit more, and add a documentation entry for the optional "brcm,write-pairing" property. Signed-off-by: Florian Fainelli --- Changes in v2: - added a description of what the BIU stands for and what write pairing is - fixed the compatible string description .../devicetree/bindings/arm/bcm/brcm,brcmstb.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt index 430608ec09f0..8ac28eb4a5a1 100644 --- a/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt +++ b/Documentation/devicetree/bindings/arm/bcm/brcm,brcmstb.txt @@ -20,6 +20,25 @@ system control is required: - compatible: "brcm,bcm-hif-cpubiuctrl", "syscon" - compatible: "brcm,bcm-hif-continuation", "syscon" +hif-cpubiuctrl node +------------------- +SoCs with Broadcom Brahma15 ARM-based CPUs have a specific Bus Interface Unit +(BIU) block which controls and interfaces the CPU complex to the different +Memory Controller Ports (MCP), one per memory controller (MEMC). This BIU block +offers a feature called Write Pairing which consists in collapsing two adjacent +cache lines into a single (bursted) write transaction towards the memory +controller (MEMC) to maximize write bandwidth. + +Required properties: + + - compatible: must be "brcm,bcm7445-hif-cpubiuctrl", "syscon" + +Optional properties: + + - brcm,write-pairing: + Boolean property, which when present indicates that the chip + supports write-pairing. + example: rdb { #address-cells = <1>; @@ -35,6 +54,7 @@ example: hif_cpubiuctrl: syscon at 3e2400 { compatible = "brcm,bcm7445-hif-cpubiuctrl", "syscon"; reg = <0x3e2400 0x5b4>; + brcm,write-pairing; }; hif_continuation: syscon at 452000 { -- 2.1.0