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[00/20] dm: Enhance of-platdata to support parent devices

Message ID 20201003173142.3213123-1-sjg@chromium.org
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Series dm: Enhance of-platdata to support parent devices | expand


Simon Glass Oct. 3, 2020, 5:31 p.m. UTC
At present dev_get_parent() always returns the root device with
of-platdata. This means that it is not possible to find the I2C bus for an
I2C device easily. In many cases this does not cause problems as there is
only a single I2C bus, but it is still inconsistent with U-Boot proper.

Worse is that because devices are not bound to the correct parent, they
will not have parent_platdata allocated correctly. Manual fix-ups are
required in the code.

This series adds support for parent devices with of-platdata.

Recent improvements to of-platadata have provided a function to obtain a
device based on its driver_info struct. This requires in generated C code
in dm_populate_phandle_data() which writes the udevice pointer into each
phandle value, since this cannot be known at build time.

This works well and fixes a big hole in of-platdata. But the
implementation has a few drawbacks: the need for generated code adds (very
slightly) to code size and it means that the SPL must sit in writable
memory. The latter can be considered a security risk and is not actually
supported on Intel Apollo Lake.

Another point is that in future of-platadata may support instantiation of
devices at build time. Pointer fix-ups could become quite taxing.

So this series adjusts the approach, storing an index (idx) to the
driver_info struct in the linker list instead. That index can be figured
out in dtoc and the value placed directly in the phandle struct. For
64-bit machines it is also smaller than a pointer. It requires a new table
(driver_rt) to be set up at runtime.

This series adds more SPL tests written in C, using the infrastructure in
the previous series (u-boot-dm/tes-working). A few clean-ups and a bug fix
resulting from these are included.

Finally, x86 is updated to use the parent support. For now, parent support
is behind a Kconfig option, but I expect this will become the default,
assuming that no major problems are found.

SPL size impact is fairly neural, slightly positive on chromebook_jerry
(Thumb-2) and slightly negative on rock64-rk3328 (aarch64):

  aarch64: spl/u-boot-spl:all +39.0 spl/u-boot-spl:rodata -5.0
           spl/u-boot-spl:text +44.0
      arm: spl/u-boot-spl:all -49.0 spl/u-boot-spl:data -80.0
           spl/u-boot-spl:text +36.0 spl/u-boot-spl:rodata -5.0

The increase in code size is due to lists_bind_drivers() having to do
multiple passes to ensure that parents are processed before children. This
could possible be reduced with a more complex linker list ordering
mechanism, but it would be a bit messy and that idea is not explored in
this series.

Simon Glass (20):
  sandbox: Drop ad-hoc device declarations in SPL
  dtoc: Document the return value of scan_structs()
  dtoc: Order the structures internally by name
  dm: core: Allow dm_warn() to be used in SPL
  dtoc: Fix widening of int to bytes
  dm: Add a C test for of-platdata properties
  sandbox: Allow selection of SPL unit tests
  dm: test: Drop of-platdata pytest
  dm: test: Add a check that all devices have a dev value
  dm: test: Add a test for of-platdata phandles
  dm: Use an allocated array for run-time device info
  sandbox: Fix up building for of-platdata
  dm: Support parent devices with of-platdata
  dm: Add a test for of-platdata parent information
  dm: core: Convert #ifdef to if() in root.c
  x86: apl: Enable SPI flash in TPL with APL_SPI_FLASH_BOOT
  x86: apl: Take advantage of the of-platdata parent support
  dm: Use driver_info index instead of pointer
  dm: Don't allow U_BOOT_DEVICE() when of-platdata is used
  dm: doc: Update the of-platadata documentation

 arch/sandbox/cpu/spl.c              |  14 +-
 arch/sandbox/cpu/start.c            |  16 +--
 arch/sandbox/dts/sandbox.dts        |   1 +
 arch/sandbox/dts/sandbox.dtsi       |  27 ++++
 arch/sandbox/include/asm/state.h    |   2 +-
 arch/x86/cpu/apollolake/Kconfig     |   2 +
 arch/x86/cpu/apollolake/spl.c       |   3 +-
 board/sandbox/sandbox.c             |   2 +
 configs/sandbox_spl_defconfig       |   5 +-
 doc/driver-model/of-plat.rst        |  42 +++---
 drivers/clk/clk-uclass.c            |   3 +-
 drivers/clk/clk_fixed_rate.c        |   4 +-
 drivers/clk/clk_sandbox.c           |   4 +-
 drivers/core/Kconfig                |  18 ++-
 drivers/core/device.c               |  23 +++-
 drivers/core/lists.c                |  70 +++++++++-
 drivers/core/root.c                 |  29 ++--
 drivers/core/util.c                 |   2 +-
 drivers/i2c/Makefile                |   2 +-
 drivers/i2c/i2c-emul-uclass.c       |   2 +
 drivers/i2c/sandbox_i2c.c           |   4 +-
 drivers/misc/irq-uclass.c           |   2 +-
 drivers/misc/p2sb-uclass.c          |  27 ++--
 drivers/misc/spltest_sandbox.c      |  35 -----
 drivers/mmc/fsl_esdhc_imx.c         |   7 +-
 drivers/rtc/rtc-uclass.c            |   2 +
 drivers/rtc/sandbox_rtc.c           |   4 +-
 drivers/serial/sandbox.c            |   3 +
 drivers/spi/ich.c                   |   4 +-
 drivers/sysreset/sysreset_sandbox.c |   2 +
 dts/Kconfig                         |  18 +++
 include/asm-generic/global_data.h   |  13 ++
 include/config_uncmd_spl.h          |   1 -
 include/dm/device-internal.h        |   2 +-
 include/dm/device.h                 |  14 ++
 include/dm/platdata.h               |  32 ++++-
 include/dm/util.h                   |   2 +-
 include/dt-structs.h                |   6 +-
 test/dm/of_platdata.c               | 203 ++++++++++++++++++++++++++++
 test/dm/test-main.c                 |  24 +++-
 test/py/tests/test_ofplatdata.py    |  47 -------
 test/py/tests/test_spl.py           |   5 +-
 tools/dtoc/dtb_platdata.py          |  63 +++++----
 tools/dtoc/dtoc_test_simple.dts     |   1 +
 tools/dtoc/fdt.py                   |   9 ++
 tools/dtoc/test_dtoc.py             | 178 ++++++++++++++++--------
 tools/dtoc/test_fdt.py              |  10 ++
 47 files changed, 705 insertions(+), 284 deletions(-)