Add a README with a brief guide to porting serial drivers over to use driver model. Add a timeline also. All serial drivers should be converted by the end of January 2016. Signed-off-by: Simon Glass <sjg@chromium.org>master
parent
bff1a71ede
commit
1d149eddcc
@ -0,0 +1,58 @@ |
|||||||
|
How to port a serial driver to driver model |
||||||
|
=========================================== |
||||||
|
|
||||||
|
About 16 of 33 serial drivers have been converted as at September 2015. It |
||||||
|
is time for maintainers to start converting over the remaining serial drivers: |
||||||
|
|
||||||
|
altera_jtag_uart.c |
||||||
|
altera_uart.c |
||||||
|
arm_dcc.c |
||||||
|
lpc32xx_hsuart.c |
||||||
|
mcfuart.c |
||||||
|
mxs_auart.c |
||||||
|
opencores_yanu.c |
||||||
|
serial_bfin.c |
||||||
|
serial_imx.c |
||||||
|
serial_lpuart.c |
||||||
|
serial_max3100.c |
||||||
|
serial_pxa.c |
||||||
|
serial_s3c24x0.c |
||||||
|
serial_sa1100.c |
||||||
|
serial_stm32.c |
||||||
|
serial_xuartlite.c |
||||||
|
usbtty.c |
||||||
|
|
||||||
|
You should complete this by the end of January 2016. |
||||||
|
|
||||||
|
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 |
Loading…
Reference in new issue