| Heinrich Schuchardt | 921e0a0 | 2023-06-21 21:24:55 +0200 | [diff] [blame] | 1 | .. SPDX-License-Identifier: GPL-2.0+: |
| 2 | |
| 3 | bind command |
| 4 | ============ |
| 5 | |
| 6 | Synopsis |
| 7 | -------- |
| 8 | |
| 9 | :: |
| 10 | |
| 11 | bind <node path> <driver> |
| 12 | bind <class> <index> <driver> |
| 13 | |
| 14 | Description |
| 15 | ----------- |
| 16 | |
| 17 | The bind command is used to bind a device to a driver. This makes the |
| 18 | device available in U-Boot. |
| 19 | |
| 20 | While binding to a *node path* typically provides a working device |
| 21 | binding by parent node and driver may lead to a device that is only |
| 22 | partially initialized. |
| 23 | |
| 24 | node path |
| 25 | path of the device's device-tree node |
| 26 | |
| 27 | class |
| 28 | device class name |
| 29 | |
| 30 | index |
| 31 | index of the parent device in the device class |
| 32 | |
| 33 | driver |
| 34 | device driver name |
| 35 | |
| 36 | Example |
| 37 | ------- |
| 38 | |
| 39 | Given a system with a real time clock device with device path */pl031@9010000* |
| 40 | and using driver rtc-pl031 unbinding and binding of the device is demonstrated |
| 41 | using the two alternative bind syntaxes. |
| 42 | |
| 43 | .. code-block:: |
| 44 | |
| 45 | => dm tree |
| 46 | Class Index Probed Driver Name |
| 47 | ----------------------------------------------------------- |
| 48 | root 0 [ + ] root_driver root_driver |
| 49 | ... |
| 50 | rtc 0 [ ] rtc-pl031 |-- pl031@9010000 |
| 51 | ... |
| 52 | => fdt addr $fdtcontroladdr |
| 53 | Working FDT set to 7ed7fdb0 |
| 54 | => fdt print |
| 55 | / { |
| 56 | interrupt-parent = <0x00008003>; |
| 57 | model = "linux,dummy-virt"; |
| 58 | #size-cells = <0x00000002>; |
| 59 | #address-cells = <0x00000002>; |
| 60 | compatible = "linux,dummy-virt"; |
| 61 | ... |
| 62 | pl031@9010000 { |
| 63 | clock-names = "apb_pclk"; |
| 64 | clocks = <0x00008000>; |
| 65 | interrupts = <0x00000000 0x00000002 0x00000004>; |
| 66 | reg = <0x00000000 0x09010000 0x00000000 0x00001000>; |
| 67 | compatible = "arm,pl031", "arm,primecell"; |
| 68 | }; |
| 69 | ... |
| 70 | } |
| 71 | => unbind /pl031@9010000 |
| 72 | => date |
| 73 | Cannot find RTC: err=-19 |
| 74 | => dm tree |
| 75 | Class Index Probed Driver Name |
| 76 | ----------------------------------------------------------- |
| 77 | root 0 [ + ] root_driver root_driver |
| 78 | ... |
| 79 | => bind /pl031@9010000 rtc-pl031 |
| 80 | => dm tree |
| 81 | Class Index Probed Driver Name |
| 82 | ----------------------------------------------------------- |
| 83 | root 0 [ + ] root_driver root_driver |
| 84 | ... |
| 85 | rtc 0 [ ] rtc-pl031 |-- pl031@9010000 |
| 86 | => date |
| 87 | Date: 2023-06-22 (Thursday) Time: 15:14:51 |
| 88 | => unbind rtc 0 rtc-pl031 |
| 89 | => bind root 0 rtc-pl031 |
| 90 | => date |
| 91 | Date: 1980-08-19 (Tuesday) Time: 14:45:30 |
| 92 | |
| 93 | Obviously the device is not initialized correctly by the last bind command. |
| 94 | |
| 95 | Configuration |
| 96 | ------------- |
| 97 | |
| 98 | The bind command is only available if CONFIG_CMD_BIND=y. |
| 99 | |
| 100 | Return code |
| 101 | ----------- |
| 102 | |
| 103 | The return code $? is 0 (true) on success and 1 (false) on failure. |