1*4882a593SmuzhiyunHow to port a serial driver to driver model 2*4882a593Smuzhiyun=========================================== 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunAlmost all of the serial drivers have been converted as at January 2016. These 5*4882a593Smuzhiyunones remain: 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun serial_bfin.c 8*4882a593Smuzhiyun serial_pxa.c 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunThe deadline for this work was the end of January 2016. If no one steps 11*4882a593Smuzhiyunforward to convert these, at some point there may come a patch to remove them! 12*4882a593Smuzhiyun 13*4882a593SmuzhiyunHere is a suggested approach for converting your serial driver over to driver 14*4882a593Smuzhiyunmodel. Please feel free to update this file with your ideas and suggestions. 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun- #ifdef out all your own serial driver code (#ifndef CONFIG_DM_SERIAL) 17*4882a593Smuzhiyun- Define CONFIG_DM_SERIAL for your board, vendor or architecture 18*4882a593Smuzhiyun- If the board does not already use driver model, you need CONFIG_DM also 19*4882a593Smuzhiyun- Your board should then build, but will not boot since there will be no serial 20*4882a593Smuzhiyun driver 21*4882a593Smuzhiyun- Add the U_BOOT_DRIVER piece at the end (e.g. copy serial_s5p.c for example) 22*4882a593Smuzhiyun- Add a private struct for the driver data - avoid using static variables 23*4882a593Smuzhiyun- Implement each of the driver methods, perhaps by calling your old methods 24*4882a593Smuzhiyun- You may need to adjust the function parameters so that the old and new 25*4882a593Smuzhiyun implementations can share most of the existing code 26*4882a593Smuzhiyun- If you convert all existing users of the driver, remove the pre-driver-model 27*4882a593Smuzhiyun code 28*4882a593Smuzhiyun 29*4882a593SmuzhiyunIn terms of patches a conversion series typically has these patches: 30*4882a593Smuzhiyun- clean up / prepare the driver for conversion 31*4882a593Smuzhiyun- add driver model code 32*4882a593Smuzhiyun- convert at least one existing board to use driver model serial 33*4882a593Smuzhiyun- (if no boards remain that don't use driver model) remove the old code 34*4882a593Smuzhiyun 35*4882a593SmuzhiyunThis may be a good time to move your board to use device tree also. Mostly 36*4882a593Smuzhiyunthis involves these steps: 37*4882a593Smuzhiyun 38*4882a593Smuzhiyun- define CONFIG_OF_CONTROL and CONFIG_OF_SEPARATE 39*4882a593Smuzhiyun- add your device tree files to arch/<arch>/dts 40*4882a593Smuzhiyun- update the Makefile there 41*4882a593Smuzhiyun- Add stdout-path to your /chosen device tree node if it is not already there 42*4882a593Smuzhiyun- build and get u-boot-dtb.bin so you can test it 43*4882a593Smuzhiyun- Your drivers can now use device tree 44*4882a593Smuzhiyun- For device tree in SPL, define CONFIG_SPL_OF_CONTROL 45