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