ALSA: hda - Modularize HD-audio driver

Split the monolithc HD-audio driver into several pieces:
 - snd-hda-intel   HD-audio PCI controller driver; loaded via udev
 - snd-hda-codec   HD-audio codec bus driver
 - snd-hda-codec-* Specific HD-audio codec drivers

When built as modules, snd-hda-codec (that is invoked by snd-hda-intel)
looks up the codec vendor ID and loads the corresponding codec module
automatically via request_module().

When built in a kernel, each codec drivers are statically hooked up
before probing the PCI.

This patch adds appropriate EXPORT_SYMBOL_GPL()'s and the module
information for each driver, and driver-linking codes between
codec-bus and codec drivers.

TODO:
  - Avoid EXPORT_SYMBOL*() when built-in kernel
  - Restore __devinit appropriately depending on the condition

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/Kconfig

@@ -46,48 +46,83 @@ config SND_HDA_CODEC_REALTEK
 	  Say Y here to include Realtek HD-audio codec support in
 	  snd-hda-intel driver, such as ALC880.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-realtek.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_ANALOG
 	bool "Build Analog Device HD-audio codec support"
 	default y
 	help
 	  Say Y here to include Analog Device HD-audio codec support in
 	  snd-hda-intel driver, such as AD1986A.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-analog.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_SIGMATEL
 	bool "Build IDT/Sigmatel HD-audio codec support"
 	default y
 	help
 	  Say Y here to include IDT (Sigmatel) HD-audio codec support in
 	  snd-hda-intel driver, such as STAC9200.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-idt.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_VIA
 	bool "Build VIA HD-audio codec support"
 	default y
 	help
 	  Say Y here to include VIA HD-audio codec support in
 	  snd-hda-intel driver, such as VT1708.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-via.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_ATIHDMI
 	bool "Build ATI HDMI HD-audio codec support"
 	default y
 	help
 	  Say Y here to include ATI HDMI HD-audio codec support in
 	  snd-hda-intel driver, such as ATI RS600 HDMI.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-atihdmi.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_NVHDMI
 	bool "Build NVIDIA HDMI HD-audio codec support"
 	default y
 	help
 	  Say Y here to include NVIDIA HDMI HD-audio codec support in
 	  snd-hda-intel driver, such as NVIDIA MCP78 HDMI.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-nvhdmi.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_INTELHDMI
 	bool "Build INTEL HDMI HD-audio codec support"
 	default y
 	help
 	  Say Y here to include INTEL HDMI HD-audio codec support in
 	  snd-hda-intel driver, such as Eaglelake integrated HDMI.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-intelhdmi.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_ELD
 	def_bool y
 	depends on SND_HDA_CODEC_INTELHDMI
@@ -99,20 +134,35 @@ config SND_HDA_CODEC_CONEXANT
 	  Say Y here to include Conexant HD-audio codec support in
 	  snd-hda-intel driver, such as CX20549.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-conexant.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_CMEDIA
 	bool "Build C-Media HD-audio codec support"
 	default y
 	help
 	  Say Y here to include C-Media HD-audio codec support in
 	  snd-hda-intel driver, such as CMI9880.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-cmedia.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_CODEC_SI3054
 	bool "Build Silicon Labs 3054 HD-modem codec support"
 	default y
 	help
 	  Say Y here to include Silicon Labs 3054 HD-modem codec
 	  (and compatibles) support in snd-hda-intel driver.
 
+	  When the HD-audio driver is built as a module, the codec
+	  support code is also built as another module,
+	  snd-hda-codec-si3054.
+	  This module is automatically loaded at probing.
+
 config SND_HDA_GENERIC
 	bool "Enable generic HD-audio codec parser"
 	default y

sound/pci/hda/Makefile

@@ -1,22 +1,59 @@
-snd-hda-intel-y := hda_intel.o
-# since snd-hda-intel is the only driver using hda-codec,
-# merge it into a single module although it was originally
-# designed to be individual modules
-snd-hda-intel-y += hda_codec.o
-snd-hda-intel-$(CONFIG_PROC_FS) += hda_proc.o
-snd-hda-intel-$(CONFIG_SND_HDA_ELD) += hda_eld.o
-snd-hda-intel-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
-snd-hda-intel-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
-snd-hda-intel-$(CONFIG_SND_HDA_GENERIC) += hda_generic.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_REALTEK) += patch_realtek.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_CMEDIA) += patch_cmedia.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_ANALOG) += patch_analog.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_SIGMATEL) += patch_sigmatel.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_SI3054) += patch_si3054.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_ATIHDMI) += patch_atihdmi.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_CONEXANT) += patch_conexant.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_VIA) += patch_via.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_NVHDMI) += patch_nvhdmi.o
-snd-hda-intel-$(CONFIG_SND_HDA_CODEC_INTELHDMI) += patch_intelhdmi.o
+snd-hda-intel-objs := hda_intel.o
 
+snd-hda-codec-y := hda_codec.o
+snd-hda-codec-$(CONFIG_SND_HDA_GENERIC) += hda_generic.o
+snd-hda-codec-$(CONFIG_PROC_FS) += hda_proc.o
+# snd-hda-codec-$(CONFIG_SND_HDA_ELD) += hda_eld.o
+snd-hda-codec-$(CONFIG_SND_HDA_HWDEP) += hda_hwdep.o
+snd-hda-codec-$(CONFIG_SND_HDA_INPUT_BEEP) += hda_beep.o
+
+snd-hda-codec-realtek-objs :=	patch_realtek.o
+snd-hda-codec-cmedia-objs :=	patch_cmedia.o
+snd-hda-codec-analog-objs :=	patch_analog.o
+snd-hda-codec-idt-objs :=	patch_sigmatel.o
+snd-hda-codec-si3054-objs :=	patch_si3054.o
+snd-hda-codec-atihdmi-objs :=	patch_atihdmi.o
+snd-hda-codec-conexant-objs :=	patch_conexant.o
+snd-hda-codec-via-objs :=	patch_via.o
+snd-hda-codec-nvhdmi-objs :=	patch_nvhdmi.o
+snd-hda-codec-intelhdmi-objs :=	patch_intelhdmi.o hda_eld.o
+
+# common driver
+obj-$(CONFIG_SND_HDA_INTEL) := snd-hda-codec.o
+
+# codec drivers (note: CONFIG_SND_HDA_CODEC_XXX are booleans)
+ifdef CONFIG_SND_HDA_CODEC_REALTEK
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-realtek.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_CMEDIA
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-cmedia.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_ANALOG
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-analog.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_SIGMATEL
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-idt.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_SI3054
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-si3054.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_ATIHDMI
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-atihdmi.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_CONEXANT
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-conexant.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_VIA
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-via.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_NVHDMI
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-nvhdmi.o
+endif
+ifdef CONFIG_SND_HDA_CODEC_INTELHDMI
+obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-codec-intelhdmi.o
+endif
+
+# this must be the last entry after codec drivers;
+# otherwise the codec patches won't be hooked before the PCI probe
+# when built in kernel
 obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-intel.o

sound/pci/hda/hda_beep.c

@@ -128,6 +128,7 @@ int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
 	INIT_WORK(&beep->beep_work, &snd_hda_generate_beep);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(snd_hda_attach_beep_device);
 
 void snd_hda_detach_beep_device(struct hda_codec *codec)
 {
@@ -140,3 +141,4 @@ void snd_hda_detach_beep_device(struct hda_codec *codec)
 		kfree(beep);
 	}
 }
+EXPORT_SYMBOL_GPL(snd_hda_detach_beep_device);