mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-25 06:00:43 +00:00
92d05e50d9
Update the README to reflect the current status. Signed-off-by: Simon Glass <sjg@chromium.org>
47 lines
2 KiB
Text
47 lines
2 KiB
Text
How to port a serial driver to driver model
|
|
===========================================
|
|
|
|
Almost all of the serial drivers have been converted as at January 2016. These
|
|
ones remain:
|
|
|
|
arm_dcc.c
|
|
mcfuart.c
|
|
serial_bfin.c
|
|
serial_pxa.c
|
|
serial_s3c24x0.c
|
|
|
|
The deadline for this work was the end of January 2016. If no one steps
|
|
forward to convert these, at some point there may come a patch to remove them!
|
|
|
|
Here is a suggested approach for converting your serial driver over to driver
|
|
model. Please feel free to update this file with your ideas and suggestions.
|
|
|
|
- #ifdef out all your own serial driver code (#ifndef CONFIG_DM_SERIAL)
|
|
- Define CONFIG_DM_SERIAL for your board, vendor or architecture
|
|
- If the board does not already use driver model, you need CONFIG_DM also
|
|
- Your board should then build, but will not boot since there will be no serial
|
|
driver
|
|
- Add the U_BOOT_DRIVER piece at the end (e.g. copy serial_s5p.c for example)
|
|
- Add a private struct for the driver data - avoid using static variables
|
|
- Implement each of the driver methods, perhaps by calling your old methods
|
|
- You may need to adjust the function parameters so that the old and new
|
|
implementations can share most of the existing code
|
|
- If you convert all existing users of the driver, remove the pre-driver-model
|
|
code
|
|
|
|
In terms of patches a conversion series typically has these patches:
|
|
- clean up / prepare the driver for conversion
|
|
- add driver model code
|
|
- convert at least one existing board to use driver model serial
|
|
- (if no boards remain that don't use driver model) remove the old code
|
|
|
|
This may be a good time to move your board to use device tree also. Mostly
|
|
this involves these steps:
|
|
|
|
- define CONFIG_OF_CONTROL and CONFIG_OF_SEPARATE
|
|
- add your device tree files to arch/<arch>/dts
|
|
- update the Makefile there
|
|
- Add stdout-path to your /chosen device tree node if it is not already there
|
|
- build and get u-boot-dtb.bin so you can test it
|
|
- Your drivers can now use device tree
|
|
- For device tree in SPL, define CONFIG_SPL_OF_CONTROL
|