From 8ecd7f5970c52240d2847e45ce3eb278e7b0021c Mon Sep 17 00:00:00 2001 From: Dirk B Date: Wed, 16 Dec 2015 08:09:10 +0100 Subject: ARM: 8483/1: Documentation: l2c: Rename l2cc to l2c2x0 The documentation in the l2cc.txt is specific to the L2 cache controllers L2C210/L2C220/L2C310 (also known as PL210/PL220/PL310 and variants) and not generic as the file name implies. It's not valid for integrated L2 controllers as found in e.g. Cortex-A15/A7/A57/A53. Reflect this by adapting the file name accordingly. Signed-off-by: Dirk Behme Signed-off-by: Russell King --- Documentation/devicetree/bindings/arm/l2c2x0.txt | 93 ++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/l2c2x0.txt (limited to 'Documentation/devicetree/bindings/arm/l2c2x0.txt') diff --git a/Documentation/devicetree/bindings/arm/l2c2x0.txt b/Documentation/devicetree/bindings/arm/l2c2x0.txt new file mode 100644 index 000000000000..06c88a4d28ac --- /dev/null +++ b/Documentation/devicetree/bindings/arm/l2c2x0.txt @@ -0,0 +1,93 @@ +* 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. +- arm,shared-override : The default behavior of the pl310 cache controller with + respect to the shareable attribute is to transform "normal memory + non-cacheable transactions" into "cacheable no allocate" (for reads) or + "write through no write allocate" (for writes). + On systems where this may cause DMA buffer corruption, this property must be + specified to indicate that such transforms are precluded. +- prefetch-data : Data prefetch. Value: <0> (forcibly disable), <1> + (forcibly enable), property absent (retain settings set by firmware) +- prefetch-instr : Instruction prefetch. Value: <0> (forcibly disable), + <1> (forcibly enable), property absent (retain settings set by + firmware) + +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