SMBIOS/SCONFIG: Allow devtree-defined Type 41 entries

Introduce the `smbios_dev_info` devicetree keyword to specify the
instance ID and RefDes (Reference Designation) of onboard devices.

Example syntax:

 device pci 1c.0 on	# PCIe Port #1
 	device pci 00.0 on
 		smbios_dev_info 6
 	end
 end
 device pci 1c.1 on	# PCIe Port #2
 	device pci 00.0 on
 		smbios_dev_info 42 "PCIe-PCI Time Machine"
 	end
 end

The `SMBIOS_TYPE41_PROVIDED_BY_DEVTREE` Kconfig option enables using
this syntax to control the generated Type 41 entries. When this option
is enabled, Type 41 entries are only autogenerated for devices with a
defined instance ID. This avoids having to keep track of which instance
IDs have been used for every device class.

Using `smbios_dev_info` when `SMBIOS_TYPE41_PROVIDED_BY_DEVTREE` is not
enabled will result in a build-time error, as the syntax is meaningless
in this case. This is done with preprocessor guards around the Type 41
members in `struct device` and the code which uses the guarded members.
Although the preprocessor usage isn't particularly elegant, adjusting
the devicetree syntax and/or grammar depending on a Kconfig option is
probably even worse.

Change-Id: Iecca9ada6ee1000674cb5dd7afd5c309d8e1a64b
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57370
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/include/device/device.h b/src/include/device/device.h
index 8610e0a4c6..237d836147 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -148,6 +148,17 @@ struct device {
 	u8 smbios_slot_data_width;
 	u8 smbios_slot_length;
 	const char *smbios_slot_designation;
+
+#if CONFIG(SMBIOS_TYPE41_PROVIDED_BY_DEVTREE)
+	/*
+	 * These fields are intentionally guarded so that attempts to use
+	 * the corresponding devicetree syntax without selecting the Kconfig
+	 * option result in build-time errors. Smaller size is a side effect.
+	 */
+	bool smbios_instance_id_valid;
+	u8 smbios_instance_id;
+	const char *smbios_refdes;
+#endif
 #endif
 #endif
 	DEVTREE_CONST void *chip_info;