Hi,
On 05-09-15 15:45, Simon Glass wrote:
Add a README with a brief guide to porting serial drivers over to use driver model.
Add a timeline also.
Signed-off-by: Simon Glass sjg@chromium.org
I assume that the purpose of the timeline is to retire the non dm serial drivers ?
What about SPL use ?
I do not see the SPL for sunxi move to dm / devicetree anytime soon, there simply does not seem to be enough space.
With the new nand SPL support we have already been hitting the 24k limit without bringing in dm + a dtb + a dtb parser ...
Which reminds me I still need to look at your version of the patch for only using malloc_simple.c in the SPL and not build in dl_malloc.c, that saves about 1k which we could use really well. I still have this on my todo list.
Regards,
Hans
I intend to cc the final patch to all U-Boot maintainers using something like this:
(for f in $(find . -name MAINTAINERS); do grep ^M: $f; done) | \ awk '{$1=""; print "Series-cc:" $0}' |sort | uniq
This is about 229 email address, of which 217 seem to be different people.
doc/driver-model/serial-howto.txt | 58 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 doc/driver-model/serial-howto.txt
diff --git a/doc/driver-model/serial-howto.txt b/doc/driver-model/serial-howto.txt new file mode 100644 index 0000000..76a75da --- /dev/null +++ b/doc/driver-model/serial-howto.txt @@ -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 Christmas 2015.
+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