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>
diff --git a/sound/pci/hda/Makefile b/sound/pci/hda/Makefile
index 6daf5fd..50f9d09 100644
--- a/sound/pci/hda/Makefile
+++ b/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