From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- Documentation/devicetree/bindings/arm/l2cc.txt | 82 ++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/l2cc.txt (limited to 'Documentation/devicetree/bindings/arm/l2cc.txt') diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt new file mode 100644 index 000000000..0dbabe9a6 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/l2cc.txt @@ -0,0 +1,82 @@ +* ARM L2 Cache Controller + +ARM cores often have a separate level 2 cache controller. There are various +implementations of the L2 cache controller with compatible programming models. +Some of the properties that are just prefixed "cache-*" are taken from section +3.7.3 of the ePAPR v1.1 specification which can be found at: +https://www.power.org/wp-content/uploads/2012/06/Power_ePAPR_APPROVED_v1.1.pdf + +The ARM L2 cache representation in the device tree should be done as follows: + +Required properties: + +- compatible : should be one of: + "arm,pl310-cache" + "arm,l220-cache" + "arm,l210-cache" + "bcm,bcm11351-a2-pl310-cache": DEPRECATED by "brcm,bcm11351-a2-pl310-cache" + "brcm,bcm11351-a2-pl310-cache": For Broadcom bcm11351 chipset where an + offset needs to be added to the address before passing down to the L2 + cache controller + "marvell,aurora-system-cache": Marvell Controller designed to be + compatible with the ARM one, with system cache mode (meaning + maintenance operations on L1 are broadcasted to the L2 and L2 + performs the same operation). + "marvell,aurora-outer-cache": Marvell Controller designed to be + compatible with the ARM one with outer cache mode. + "marvell,tauros3-cache": Marvell Tauros3 cache controller, compatible + with arm,pl310-cache controller. +- cache-unified : Specifies the cache is a unified cache. +- cache-level : Should be set to 2 for a level 2 cache. +- reg : Physical base address and size of cache controller's memory mapped + registers. + +Optional properties: + +- arm,data-latency : Cycles of latency for Data RAM accesses. Specifies 3 cells of + read, write and setup latencies. Minimum valid values are 1. Controllers + without setup latency control should use a value of 0. +- arm,tag-latency : Cycles of latency for Tag RAM accesses. Specifies 3 cells of + read, write and setup latencies. Controllers without setup latency control + should use 0. Controllers without separate read and write Tag RAM latency + values should only use the first cell. +- arm,dirty-latency : Cycles of latency for Dirty RAMs. This is a single cell. +- arm,filter-ranges : Starting address and length of window to + filter. Addresses in the filter window are directed to the M1 port. Other + addresses will go to the M0 port. +- arm,io-coherent : indicates that the system is operating in an hardware + I/O coherent mode. Valid only when the arm,pl310-cache compatible + string is used. +- interrupts : 1 combined interrupt. +- cache-size : specifies the size in bytes of the cache +- cache-sets : specifies the number of associativity sets of the cache +- cache-block-size : specifies the size in bytes of a cache block +- cache-line-size : specifies the size in bytes of a line in the cache, + if this is not specified, the line size is assumed to be equal to the + cache block size +- cache-id-part: cache id part number to be used if it is not present + on hardware +- wt-override: If present then L2 is forced to Write through mode +- arm,double-linefill : Override double linefill enable setting. Enable if + non-zero, disable if zero. +- arm,double-linefill-incr : Override double linefill on INCR read. Enable + if non-zero, disable if zero. +- arm,double-linefill-wrap : Override double linefill on WRAP read. Enable + if non-zero, disable if zero. +- arm,prefetch-drop : Override prefetch drop enable setting. Enable if non-zero, + disable if zero. +- arm,prefetch-offset : Override prefetch offset value. Valid values are + 0-7, 15, 23, and 31. + +Example: + +L2: cache-controller { + compatible = "arm,pl310-cache"; + reg = <0xfff12000 0x1000>; + arm,data-latency = <1 1 1>; + arm,tag-latency = <2 2 2>; + arm,filter-ranges = <0x80000000 0x8000000>; + cache-unified; + cache-level = <2>; + interrupts = <45>; +}; -- cgit v1.2.3-54-g00ecf