Kumar, On Wednesday 05 February 2014 02:46 PM, Ivan Khoronzhuk wrote: > Add bindings for TI Async External Memory Interface (AEMIF) controller. > > The Async External Memory Interface (EMIF16/AEMIF) controller is intended to > provide a glue-less interface to a variety of asynchronous memory devices like > ASRA M, NOR and NAND memory. A total of 256M bytes of any of these memories > can be accessed via 4 chip selects with 64M byte access per chip select. > > We are not encoding CS number in reg property, it's memory partition number. > The CS number is encoded for Davinci NAND node using standalone property > "ti,davinci-chipselect" and we need to provide two memory ranges to it, > as result we can't encode CS number in "reg" for AEMIF child devices > (NAND/NOR/etc), as it will break bindings compatibility. > > In this patch, NAND node is used just as an example of child node. > > Signed-off-by: Ivan Khoronzhuk <[email protected]> > --- Can you please have a look at the binding which we discussed in previous versions ? I want to queue these for 3.15 via Greg's tree but need your ack on DT part at least.
> .../bindings/memory-controllers/ti-aemif.txt | 210 > +++++++++++++++++++++ > 1 file changed, 210 insertions(+) > create mode 100644 > Documentation/devicetree/bindings/memory-controllers/ti-aemif.txt > > diff --git > a/Documentation/devicetree/bindings/memory-controllers/ti-aemif.txt > b/Documentation/devicetree/bindings/memory-controllers/ti-aemif.txt > new file mode 100644 > index 0000000..d1466dc > --- /dev/null > +++ b/Documentation/devicetree/bindings/memory-controllers/ti-aemif.txt > @@ -0,0 +1,210 @@ > +* Device tree bindings for Texas instruments AEMIF controller > + > +The Async External Memory Interface (EMIF16/AEMIF) controller is intended to > +provide a glue-less interface to a variety of asynchronous memory devices > like > +ASRA M, NOR and NAND memory. A total of 256M bytes of any of these memories > +can be accessed at any given time via four chip selects with 64M byte access > +per chip select. Synchronous memories such as DDR1 SD RAM, SDR SDRAM > +and Mobile SDR are not supported. > + > +Documentation: > +Davinci DM646x - http://www.ti.com/lit/ug/sprueq7c/sprueq7c.pdf > +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf > +Kestone - http://www.ti.com/lit/ug/sprugz3a/sprugz3a.pdf > + > +Required properties: > + > +- compatible: "ti,davinci-aemif" > + "ti,keystone-aemif" > + "ti,da850-aemif" > + > +- reg: contains offset/length value for AEMIF control > registers > + space. > + > +- #address-cells: Must be 2. The partition number has to be encoded in the > + first address cell and it may accept values 0..N-1 > + (N - total number of partitions). It's recommended to > + assign N-1 number for the control partition. The second > + cell is the offset into the partition. > + > +- #size-cells: Must be set to 1. > + > +- ranges: Contains memory regions. There are two types of > + ranges/partitions: > + - CS-specific partition/range. If continuous, must be > + set up to reflect the memory layout for 4 chipselects, > + if not then additional range/partition can be added and > + child device can select the proper one. > + - control partition which is common for all CS > + interfaces. > + > +- clocks: the clock feeding the controller clock. Required only > + if clock tree data present in device tree. > + See clock-bindings.txt > + > +- clock-names: clock name. It has to be "aemif". Required only > if clock > + tree data present in device tree, in another case don't > + use it. > + See clock-bindings.txt > + > +- clock-ranges: Empty property indicating that child nodes can > inherit > + named clocks. Required only if clock tree data present > + in device tree. > + See clock-bindings.txt > + > + > +Child chip-select (cs) nodes contain the memory devices nodes connected to > +such as NOR (e.g. cfi-flash) and NAND (ti,davinci-nand, see > davinci-nand.txt). > +There might be board specific devices like FPGAs. > + > +Required child cs node properties: > + > +- #address-cells: Must be 2. > + > +- #size-cells: Must be 1. > + > +- ranges: Empty property indicating that child nodes can inherit > + memory layout. > + > +- clock-ranges: Empty property indicating that child nodes can > inherit > + named clocks. Required only if clock tree data present > + in device tree. > + > +- ti,cs-chipselect: number of chipselect. Indicates on the aemif driver > + which chipselect is used for accessing the memory. For > + compatibles "ti,davinci-aemif" and "ti,keystone-aemif" > + it can be in range [0-3]. For compatible > + "ti,da850-aemif" range is [2-5]. > + > +Optional child cs node properties: > + > +- ti,bus-width: width of the asynchronous device's data > bus > + 8 or 16 if not preset 8 > + > +- ti,cs-ss: enable/disable select strobe mode > + In select strobe mode chip select behaves as > + the strobe and is active only during the strobe > + period. If present then enable. > + > +- ti,cs-ew: enable/disable extended wait mode > + if set, the controller monitors the EMIFWAIT pin > + mapped to that chip select to determine if the > + device wants to extend the strobe period. If > + present then enable. > + > +- ti,cs-ta: minimum turn around time, ns > + Time between the end of one asynchronous memory > + access and the start of another asynchronous > + memory access. This delay is not incurred > + between a read followed by read or a write > + followed by a write to same chip select. > + > +- ti,cs-rsetup: read setup width, ns > + Time between the beginning of a memory cycle > + and the activation of read strobe. > + Minimum value is 1 (0 treated as 1). > + > +- ti,cs-rstobe: read strobe width, ns > + Time between the activation and deactivation of > + the read strobe. > + Minimum value is 1 (0 treated as 1). > + > +- ti,cs-rhold: read hold width, ns > + Time between the deactivation of the read > + strobe and the end of the cycle (which may be > + either an address change or the deactivation of > + the chip select signal. > + Minimum value is 1 (0 treated as 1). > + > +- ti,cs-wsetup: write setup width, ns > + Time between the beginning of a memory cycle > + and the activation of write strobe. > + Minimum value is 1 (0 treated as 1). > + > +- ti,cs-wstrobe: write strobe width, ns > + Time between the activation and deactivation of > + the write strobe. > + Minimum value is 1 (0 treated as 1). > + > +- ti,cs-whold: write hold width, ns > + Time between the deactivation of the write > + strobe and the end of the cycle (which may be > + either an address change or the deactivation of > + the chip select signal. > + Minimum value is 1 (0 treated as 1). > + > +If any of the above parameters are absent, current parameter value will be > taken > +from the corresponding HW reg. > + > +Example for aemif, davinci nand and nor flash chip select shown below. > + > +memory-controller@21000A00 { > + compatible = "ti,davinci-aemif"; > + #address-cells = <2>; > + #size-cells = <1>; > + clocks = <&clkaemif 0>; > + clock-names = "aemif"; > + clock-ranges; > + reg = <0x2100A00 0x00000100>; > + ranges = <0 0 0x70000000 0x10000000 > + 1 0 0x21000A00 0x0000100>; > + /* > + * Partition0: CS-specific memory range which is > + * implemented as continuous physical memory region > + * Partition1: control memory range > + */ > + > + nand:cs2 { > + #address-cells = <2>; > + #size-cells = <1>; > + clock-ranges; > + ranges; > + > + ti,cs-chipselect = <2>; > + /* all timings in nanoseconds */ > + ti,cs-ta = <0>; > + ti,cs-rhold = <7>; > + ti,cs-rstrobe = <42>; > + ti,cs-rsetup = <14>; > + ti,cs-whold = <7>; > + ti,cs-wstrobe = <42>; > + ti,cs-wsetup = <14>; > + > + nand@0,0x8000000 { > + compatible = "ti,davinci-nand"; > + reg = <0 0x8000000 0x4000000 > + 1 0x0000000 0x0000100>; > + /* > + * Partition0, offset 0x8000000, size 0x4000000 > + * Partition1, offset 0x0000000, size 0x0000100 > + */ > + > + .. see davinci-nand.txt > + }; > + }; > + > + nor:cs0 { > + #address-cells = <2>; > + #size-cells = <1>; > + clock-ranges; > + ranges; > + > + ti,cs-chipselect = <0>; > + /* all timings in nanoseconds */ > + ti,cs-ta = <0>; > + ti,cs-rhold = <8>; > + ti,cs-rstrobe = <40>; > + ti,cs-rsetup = <14>; > + ti,cs-whold = <7>; > + ti,cs-wstrobe = <40>; > + ti,cs-wsetup = <14>; > + ti,cs-asize = <1>; > + > + flash@0,0x0000000 { > + compatible = "cfi-flash"; > + reg = <0 0x0000000 0x4000000>; > + > + ... > + }; > + }; > +}; > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
