projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 275876e2 XL |
1 | Device-Tree binding for regmap |
| 2 | ||
| 3 | The endianness mode of CPU & Device scenarios: | |
| 4 | Index Device Endianness properties | |
| 5 | --------------------------------------------------- | |
| 6 | 1 BE 'big-endian' | |
| 7 | 2 LE 'little-endian' | |
| a06c488d | 8 | 3 Native 'native-endian' |
| 275876e2 XL |
9 | |
| 10 | For one device driver, which will run in different scenarios above | |
| 11 | on different SoCs using the devicetree, we need one way to simplify | |
| 12 | this. | |
| 13 | ||
| a06c488d MB |
14 | Optional properties: |
| 15 | - {big,little,native}-endian: these are boolean properties, if absent | |
| 16 | then the implementation will choose a default based on the device | |
| 17 | being controlled. These properties are for register values and all | |
| 18 | the buffers only. Native endian means that the CPU and device have | |
| 19 | the same endianness. | |
| 275876e2 XL |
20 | |
| 21 | Examples: | |
| 22 | Scenario 1 : CPU in LE mode & device in LE mode. | |
| 23 | dev: dev@40031000 { | |
| 24 | compatible = "name"; | |
| 25 | reg = <0x40031000 0x1000>; | |
| 26 | ... | |
| 27 | }; | |
| 28 | ||
| 29 | Scenario 2 : CPU in LE mode & device in BE mode. | |
| 30 | dev: dev@40031000 { | |
| 31 | compatible = "name"; | |
| 32 | reg = <0x40031000 0x1000>; | |
| 33 | ... | |
| 34 | big-endian; | |
| 35 | }; | |
| 36 | ||
| 37 | Scenario 3 : CPU in BE mode & device in BE mode. | |
| 38 | dev: dev@40031000 { | |
| 39 | compatible = "name"; | |
| 40 | reg = <0x40031000 0x1000>; | |
| 41 | ... | |
| 42 | }; | |
| 43 | ||
| 44 | Scenario 4 : CPU in BE mode & device in LE mode. | |
| 45 | dev: dev@40031000 { | |
| 46 | compatible = "name"; | |
| 47 | reg = <0x40031000 0x1000>; | |
| 48 | ... | |
| 49 | little-endian; | |
| 50 | }; |