Kumar, On Tuesday 26 November 2013 11:27 AM, Grygorii Strashko wrote: > On 11/22/2013 11:04 PM, Kumar Gala wrote: >> >> On Nov 20, 2013, at 9:46 AM, Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxx> wrote: >> >>> Add bindings for AEMIF controller drivers/memory/ti-aemif.c >>> >> >> Binding shouldn’t normally refer to code. >> >> Just saying something like: >> >> Adding binging for TI Async External Memory Interface (AEMIF) controller. >> >> >>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxx> >>> --- >>> .../bindings/memory-controllers/ti-aemif.txt | 198 ++++++++++++++++++++ >>> 1 file changed, 198 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..be0c0cb >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/memory-controllers/ti-aemif.txt >>> @@ -0,0 +1,198 @@ >>> +* Device tree bindings for Texas instruments AEMIF controller >>> + >>> +Th Async External Memory Interface (EMIF16/AEMIF) controller is intended to >> >> The? >> >>> +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 - 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,omap-L138-aemif" >>> + >>> +- #address-cells: Must be 2. The first cell is the memory partition >>> + number. The 0 partition is for chip selects. And the >>> + second cell is the offset into the partition, for the 0 >>> + partition it corresponds to chip select offset. >>> + >> >> Is the first cell just the chip select number? > > No. It's rather memory range/partition number. Now there are 2 partitions: > - control partition which is common for all CS interfaces > - CS-specific partition/range > (this one can be splitted according to specific SoC requirement) > > As per Keystone TCI6638K2K > Datasheet http://www.ti.com/lit/ds/sprs836d/sprs836d.pdf: > > 1) the memory range 0 will be from 0x30000000 size 0x10000000: > 00 3000 0000 - 00 33FF FFFF 64M EMIF16 CE0 > 00 3400 0000 - 00 37FF FFFF 64M EMIF16 CE1 > 00 3800 0000 - 00 3BFF FFFF 64M EMIF16 CE2 > 00 3C00 0000 - 00 3FFF FFFF 64M EMIF16 CE3 > > 2) the memory range 1: > 00 2100 0A00 - 00 2100 0AFF 256 AEMIF Config > > And AEMIF node contains definition: > ranges = <0 0 0x30000000 0x10000000 > 1 0 0x21000A00 0x0000100>; > > > Child node has (nand): > reg = <0 0 0x4000000 (cs0) > - or - 0 0x4000000 0x4000000 (cs1) > - or - 0 0x8000000 0x4000000 (cs2) > - or - 0 0xC000000 0x4000000 (cs3) > - and - > 1 0 0x0000100>; (for all cs) > > For example for cs2 child node the resulting mem range 0 will be calculated as > > from: 0x30000000 + (0 0x8000000 - 0 0) > size: 0x4000000 > > We don't encode CS number in reg/ranges, because it will allow simply change > AEMIF DT definitions depending on each SoC > (AEMIF CS memory range can be continuous as above or not, if not - additional > range/partition can be added and child device can select the proper one). > >> >> I’m wondering if this is similar to FSL Localbus controller, see the binding: >> >> bindings/powerpc/fsl/lbc.txt > > Don't think so :) it looks similar just because of using standard bindings > (gpmc-nand.c mvebu-devbus.txt ti-gpmc.txt and etc.) > >> >>> +- #size-cells: Must be set to 1. >>> + >>> +- reg: contains offset/length value for AEMIF control registers >>> + space. >>> + >>> +- ranges: Must be set up to reflect the memory layout for 4 >>> + chipselects and for AEMIF control range. >>> + >>> +- clocks: phandle reference to the controller clock. Required only >>> + if clock tree data present in device tree. >>> + See clock-bindings.txt Are you ok with above description on why cs property is needed. We will need your ack ;-) to take these patches forward. Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
