1 How to port a serial driver to driver model
2 ===========================================
4 About 16 of 33 serial drivers have been converted as at September 2015. It
5 is time for maintainers to start converting over the remaining serial drivers:
22 You should complete this by the end of January 2016.
24 Here is a suggested approach for converting your serial driver over to driver
25 model. Please feel free to update this file with your ideas and suggestions.
27 - #ifdef out all your own serial driver code (#ifndef CONFIG_DM_SERIAL)
28 - Define CONFIG_DM_SERIAL for your board, vendor or architecture
29 - If the board does not already use driver model, you need CONFIG_DM also
30 - Your board should then build, but will not boot since there will be no serial
32 - Add the U_BOOT_DRIVER piece at the end (e.g. copy serial_s5p.c for example)
33 - Add a private struct for the driver data - avoid using static variables
34 - Implement each of the driver methods, perhaps by calling your old methods
35 - You may need to adjust the function parameters so that the old and new
36 implementations can share most of the existing code
37 - If you convert all existing users of the driver, remove the pre-driver-model
40 In terms of patches a conversion series typically has these patches:
41 - clean up / prepare the driver for conversion
42 - add driver model code
43 - convert at least one existing board to use driver model serial
44 - (if no boards remain that don't use driver model) remove the old code
46 This may be a good time to move your board to use device tree also. Mostly
47 this involves these steps:
49 - define CONFIG_OF_CONTROL and CONFIG_OF_SEPARATE
50 - add your device tree files to arch/<arch>/dts
51 - update the Makefile there
52 - Add stdout-path to your /chosen device tree node if it is not already there
53 - build and get u-boot-dtb.bin so you can test it
54 - Your drivers can now use device tree
55 - For device tree in SPL, define CONFIG_SPL_OF_CONTROL