linux: add SOF nocodec mode

The nocodec mode is required if there is no ACPI codec HID, otherwise
the kernel will throw an error such as

[    9.612127] sof-audio-pci 0000:00:0d.0: error: no matching ASoC
machine driver found - aborting probe
[    9.621634] sof-audio-pci 0000:00:0d.0: error: failed to get
machine info -19
[    9.629027] sof-audio-pci 0000:00:0d.0: error: failed to probe DSP
hardware!

Note that /lib/firmware/intel/sof/sof-byt.ri and
/lib/firmware/intel/sof-tplg/sof-byt.tplg files need to be present for
the probe to succeed, the nocodec mode depends on them

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

meta-intel-edison-bsp/recipes-kernel/linux/files/sof_nocodec.cfg

@@ -0,0 +1,40 @@
+# Disable legacy audio drivers
+# CONFIG_SND_SST_ATOM_HIFI2_PLATFORM_PCI is not set
+# CONFIG_SND_SST_ATOM_HIFI2_PLATFORM_ACPI is not set
+
+# Generic SOF selections
+CONFIG_SND_SOC_SOF_TOPLEVEL=y
+CONFIG_SND_SOC_SOF_PCI=m
+
+# Merrifield support
+CONFIG_SND_SOC_SOF_MERRIFIELD_SUPPORT=y
+
+# enable nocodec mode
+CONFIG_EXPERT=y
+CONFIG_SND_SOC_SOF_DEVELOPER_SUPPORT=y
+CONFIG_SND_SOC_SOF_NOCODEC_SUPPORT=y
+CONFIG_SND_SOC_SOF_HDA_LINK=n
+
+# Debug options disabled, but can be turned on at will
+# CONFIG_SND_SOC_SOF_DEBUG is not set
+# CONFIG_SND_SOC_SOF_STRICT_ABI_CHECKS is not set
+# CONFIG_SND_SOC_SOF_DEBUG_VERBOSE_IPC=y
+# CONFIG_SND_SOC_SOF_DEBUG_ENABLE_DEBUGFS_CACHE=y
+# CONFIG_SND_SOC_SOF_DEBUG_ENABLE_FIRMWARE_TRACE=y
+# CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST=y
+# CONFIG_SND_SOC_SOF_DEBUG_IPC_FLOOD_TEST_CLIENT=m
+# CONFIG_SND_SOC_SOF_DEBUG_PROBES_CLIENT=m
+# CONFIG_SND_SOC_SOF_DEBUG_RETAIN_DSP_CONTEXT=y
+
+# Disable options that aren't useful for Edison
+# CONFIG_SND_SOC_SOF_BROADWELL_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_APOLLOLAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_GEMINILAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_CANNONLAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_COFFEELAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_ICELAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_COMETLAKE_LP_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_COMETLAKE_H_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_TIGERLAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_ELKHARTLAKE_SUPPORT is not set
+# CONFIG_SND_SOC_SOF_JASPERLAKE_SUPPORT is not set

meta-intel-edison-bsp/recipes-kernel/linux/linux-yocto_5.6.0.bb

@@ -15,6 +15,7 @@ SRC_URI = "git://github.com/edison-fw/linux.git;protocol=https;branch=eds-acpi-$
         file://leds.cfg \
         file://bpf.cfg \
         file://btrfs.cfg \
+        file://sof_nocodec.cfg \
         "
 
 # kernel patches