ASoC: intel: Fix sst-dsp dependency on dw stuff

The recent commit [a92ea59b74e2: ASoC: Intel: sst: only select
sst-firmware when DW DMAC is built-in] introduced more strict kconfig
dependency (depends on DW_DMAC_CORE=y) for avoiding the build failures
due to dependency messes in intel-sst.  This makes, however, it
impossible to use this driver with the modularized systems,
i.e. typically on Linux distros.

The problem addressed in the commit above is that sst_dsp_new() and
sst_dsp_free() includes the firmware init / finish that call dw_*()
functions.  Thus building it as built-in with DW_DMAC_CORE module
results in the missing symbols.

However, these sst_dsp functions are basically called only from the
drivers that depend on DW_DMAC_CORE already.  That is, once when these
functions are split out, the rest can be independent from dw stuff.

This patch attempts to solve the issue by the following:
- Split sst-dsp stuff into two modules: snd-soc-sst-dsp and
  snd-soc-sst-firmware.
- Move sst_dsp_new() and sst_dsp_free() to the latter module so that
  the former module can be independent from DW_DMAC_CORE.
- Add a new kconfig SND_SOC_INTEL_SST_FIRMWARE to select the latter
  module by machine drivers.

One only remaining pitfall is that each machine driver has to select
SND_SOC_INTEL_SST_FIRMWARE carefully depending on DW_DMAC_CORE.
This can't be done cleanly due to the restriction of the current
kbuild.

Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=988117
Fixes: a92ea59b74e2 ('ASoC: Intel: sst: only select sst-firmware when DW DMAC is built-in')
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 14 insertions, 4 deletions

diff --git a/sound/soc/intel/Kconfig b/sound/soc/intel/Kconfig
index 9c86459d0fc3..a20c3dfbcb5d 100644
--- a/sound/soc/intel/Kconfig
+++ b/sound/soc/intel/Kconfig
@@ -32,6 +32,12 @@ config SND_SOC_INTEL_SST
 	select SND_SOC_INTEL_SST_MATCH if ACPI
 	depends on (X86 || COMPILE_TEST)
 
+# firmware stuff depends DW_DMAC_CORE; since there is no depends-on from
+# the reverse selection, each machine driver needs to select
+# SND_SOC_INTEL_SST_FIRMWARE carefully depending on DW_DMAC_CORE
+config SND_SOC_INTEL_SST_FIRMWARE
+	tristate
+
 config SND_SOC_INTEL_SST_ACPI
 	tristate
 
@@ -47,8 +53,9 @@ config SND_SOC_INTEL_BAYTRAIL
 config SND_SOC_INTEL_HASWELL_MACH
 	tristate "ASoC Audio DSP support for Intel Haswell Lynxpoint"
 	depends on X86_INTEL_LPSS && I2C && I2C_DESIGNWARE_PLATFORM
-	depends on DW_DMAC_CORE=y
+	depends on DW_DMAC_CORE
 	select SND_SOC_INTEL_SST
+	select SND_SOC_INTEL_SST_FIRMWARE
 	select SND_SOC_INTEL_HASWELL
 	select SND_SOC_RT5640
 	help
@@ -91,8 +98,9 @@ config SND_SOC_INTEL_BXT_RT298_MACH
 config SND_SOC_INTEL_BYT_RT5640_MACH
 	tristate "ASoC Audio driver for Intel Baytrail with RT5640 codec"
 	depends on X86_INTEL_LPSS && I2C
-	depends on DW_DMAC_CORE=y && (SND_SST_IPC_ACPI = n)
+	depends on DW_DMAC_CORE && (SND_SST_IPC_ACPI = n)
 	select SND_SOC_INTEL_SST
+	select SND_SOC_INTEL_SST_FIRMWARE
 	select SND_SOC_INTEL_BAYTRAIL
 	select SND_SOC_RT5640
 	help
@@ -103,8 +111,9 @@ config SND_SOC_INTEL_BYT_RT5640_MACH
 config SND_SOC_INTEL_BYT_MAX98090_MACH
 	tristate "ASoC Audio driver for Intel Baytrail with MAX98090 codec"
 	depends on X86_INTEL_LPSS && I2C
-	depends on DW_DMAC_CORE=y && (SND_SST_IPC_ACPI = n)
+	depends on DW_DMAC_CORE && (SND_SST_IPC_ACPI = n)
 	select SND_SOC_INTEL_SST
+	select SND_SOC_INTEL_SST_FIRMWARE
 	select SND_SOC_INTEL_BAYTRAIL
 	select SND_SOC_MAX98090
 	help
@@ -115,8 +124,9 @@ config SND_SOC_INTEL_BROADWELL_MACH
 	tristate "ASoC Audio DSP support for Intel Broadwell Wildcatpoint"
 	depends on X86_INTEL_LPSS && I2C && DW_DMAC && \
 		   I2C_DESIGNWARE_PLATFORM
-	depends on DW_DMAC_CORE=y
+	depends on DW_DMAC_CORE
 	select SND_SOC_INTEL_SST
+	select SND_SOC_INTEL_SST_FIRMWARE
 	select SND_SOC_INTEL_HASWELL
 	select SND_SOC_RT286
 	help