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
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How to port a serial driver to driver model |
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About 16 of 33 serial drivers have been converted as at September 2015. It |
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is time for maintainers to start converting over the remaining serial drivers: |
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altera_jtag_uart.c |
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altera_uart.c |
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arm_dcc.c |
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lpc32xx_hsuart.c |
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mcfuart.c |
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mxs_auart.c |
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opencores_yanu.c |
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serial_bfin.c |
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serial_imx.c |
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serial_lpuart.c |
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serial_max3100.c |
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serial_pxa.c |
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serial_s3c24x0.c |
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serial_sa1100.c |
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serial_stm32.c |
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serial_xuartlite.c |
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usbtty.c |
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You should complete this by the end of January 2016. |
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Here is a suggested approach for converting your serial driver over to driver |
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model. Please feel free to update this file with your ideas and suggestions. |
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- #ifdef out all your own serial driver code (#ifndef CONFIG_DM_SERIAL) |
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- Define CONFIG_DM_SERIAL for your board, vendor or architecture |
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- If the board does not already use driver model, you need CONFIG_DM also |
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- Your board should then build, but will not boot since there will be no serial |
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driver |
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- Add the U_BOOT_DRIVER piece at the end (e.g. copy serial_s5p.c for example) |
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- Add a private struct for the driver data - avoid using static variables |
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- Implement each of the driver methods, perhaps by calling your old methods |
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- You may need to adjust the function parameters so that the old and new |
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implementations can share most of the existing code |
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- If you convert all existing users of the driver, remove the pre-driver-model |
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code |
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In terms of patches a conversion series typically has these patches: |
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- clean up / prepare the driver for conversion |
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- add driver model code |
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- convert at least one existing board to use driver model serial |
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- (if no boards remain that don't use driver model) remove the old code |
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This may be a good time to move your board to use device tree also. Mostly |
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this involves these steps: |
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- define CONFIG_OF_CONTROL and CONFIG_OF_SEPARATE |
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- add your device tree files to arch/<arch>/dts |
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- update the Makefile there |
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- Add stdout-path to your /chosen device tree node if it is not already there |
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- build and get u-boot-dtb.bin so you can test it |
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- Your drivers can now use device tree |
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- For device tree in SPL, define CONFIG_SPL_OF_CONTROL |
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