Add scan_bus operation to fast_spi device operations to enable
discovery of statically defined child devices.
This allows device drivers such as drivers/pc80/tpm that are
physically connected to the fast_spi bus to be properly
enumerated and initialized during device tree scanning.
Without this change, child devices defined in devicetree under
fast_spi would not be discovered, preventing proper driver
binding and initialization.
Example devicetree configuration:
```
device ref fast_spi on
chip drivers/pc80/tpm # SPI TPM header
device pnp 0c31.0 on end
end
end
```
Without a .scan_bus hook in fast_spi_dev_ops, coreboot's
BS_DEV_ENUMERATE phase never creates the pnp 0c31.0 device. As a
result, in BS_DEV_RESOURCES you see, that the device PNP 0c31.0
is missing its function "read_resources":
```
(in BS_DEV_ENUMERATE)
[DEBUG] scan_bus: bus PCI: 00:00:1f.4 finished in 11 msecs
[DEBUG] scan_bus: bus DOMAIN: 00000000 finished in 1510 msecs
[SPEW ] scan_static_bus for Root Device done
... (in BS_DEV_RESOURCES)
[SPEW ] PCI: 00:00:1f.5 read_resources segment group 0 bus 0
[ERROR] PNP: 0c31.0 missing read_resources
[SPEW ] PCI: 00:00:1f.5 read_resources segment group 0 bus 0 done
[SPEW ] DOMAIN: 00000000 read_resources segment group 0 bus 0 done
[SPEW ] Root Device read_resources segment group 0 bus 0 done
[INFO ] Done reading resources.
```
With the implementation of scan_bus, the log shows that the resources
are allocated correctly:
```
(in BS_DEV_ENUMERATE)
[DEBUG] scan_bus: bus PCI: 00:00:1f.4 finished in 11 msecs
[DEBUG] PCI: 00:00:1f.5 scanning...
[SPEW ] scan_static_bus for PCI: 00:00:1f.5
[DEBUG] PNP: 0c31.0 enabled
[SPEW ] scan_static_bus for PCI: 00:00:1f.5 done
[DEBUG] scan_bus: bus PCI: 00:00:1f.5 finished in 14 msecs
[DEBUG] scan_bus: bus DOMAIN: 00000000 finished in 1536 msecs
[SPEW ] scan_static_bus for Root Device done
... (in BS_DEV_RESOURCES)
[SPEW ] PCI: 00:00:1f.5 read_resources segment group 0 bus 0
[SPEW ] dev: PNP: 0c31.0, index: 0x0, base: 0xfed40000, size: 0x5000
[SPEW ] PCI: 00:00:1f.5 read_resources segment group 0 bus 0 done
[SPEW ] DOMAIN: 00000000 read_resources segment group 0 bus 0 done
[SPEW ] Root Device read_resources segment group 0 bus 0 done
[INFO ] Done reading resources.
```
TEST=Verified on Siemens mc_rpl1 mainboard. TPM device properly
enumerated with scan_bus implementation.
Change-Id: I4049d2d3cd5132362a7efd551dc9dd78cd24b9eb
Signed-off-by: Kilian Krause <kilian.krause@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88966
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
c71071397f