projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 041cadca MS |
1 | External Memory Interface |
| 2 | ------------------------- | |
| 3 | ||
| 4 | The emifa node describes a simple external bus controller found on some C6X | |
| 5 | SoCs. This interface provides external busses with a number of chip selects. | |
| 6 | ||
| 7 | Required properties: | |
| 8 | ||
| 9 | - compatible: must be "ti,c64x+emifa", "simple-bus" | |
| 10 | - reg: register area base and size | |
| 11 | - #address-cells: must be 2 (chip-select + offset) | |
| 12 | - #size-cells: must be 1 | |
| 13 | - ranges: mapping from EMIFA space to parent space | |
| 14 | ||
| 15 | ||
| 16 | Optional properties: | |
| 17 | ||
| 18 | - ti,dscr-dev-enable: Device ID if EMIF is enabled/disabled from DSCR | |
| 19 | ||
| 20 | - ti,emifa-burst-priority: | |
| 21 | Number of memory transfers after which the EMIF will elevate the priority | |
| 22 | of the oldest command in the command FIFO. Setting this field to 255 | |
| 23 | disables this feature, thereby allowing old commands to stay in the FIFO | |
| 24 | indefinitely. | |
| 25 | ||
| 26 | - ti,emifa-ce-config: | |
| 27 | Configuration values for each of the supported chip selects. | |
| 28 | ||
| 29 | Example: | |
| 30 | ||
| 31 | emifa@70000000 { | |
| 32 | compatible = "ti,c64x+emifa", "simple-bus"; | |
| 33 | #address-cells = <2>; | |
| 34 | #size-cells = <1>; | |
| 35 | reg = <0x70000000 0x100>; | |
| 36 | ranges = <0x2 0x0 0xa0000000 0x00000008 | |
| 37 | 0x3 0x0 0xb0000000 0x00400000 | |
| 38 | 0x4 0x0 0xc0000000 0x10000000 | |
| 39 | 0x5 0x0 0xD0000000 0x10000000>; | |
| 40 | ||
| 41 | ti,dscr-dev-enable = <13>; | |
| 42 | ti,emifa-burst-priority = <255>; | |
| 43 | ti,emifa-ce-config = <0x00240120 | |
| 44 | 0x00240120 | |
| 45 | 0x00240122 | |
| 46 | 0x00240122>; | |
| 47 | ||
| 48 | flash@3,0 { | |
| 49 | #address-cells = <1>; | |
| 50 | #size-cells = <1>; | |
| 51 | compatible = "cfi-flash"; | |
| 52 | reg = <0x3 0x0 0x400000>; | |
| 53 | bank-width = <1>; | |
| 54 | device-width = <1>; | |
| 55 | partition@0 { | |
| 56 | reg = <0x0 0x400000>; | |
| 57 | label = "NOR"; | |
| 58 | }; | |
| 59 | }; | |
| 60 | }; | |
| 61 | ||
| 62 | This shows a flash chip attached to chip select 3. |