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>

1 files changed, 50 insertions, 0 deletions

diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
index 7c60f1a..717040a 100644
--- a/sound/pci/hda/Kconfig
+++ b/sound/pci/hda/Kconfig
@@ -46,6 +46,11 @@ 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
@@ -53,6 +58,11 @@ config SND_HDA_CODEC_ANALOG
 	  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
@@ -60,6 +70,11 @@ config SND_HDA_CODEC_SIGMATEL
 	  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
@@ -67,6 +82,11 @@ config SND_HDA_CODEC_VIA
 	  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
@@ -74,6 +94,11 @@ config SND_HDA_CODEC_ATIHDMI
 	  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
@@ -81,6 +106,11 @@ config SND_HDA_CODEC_NVHDMI
 	  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
@@ -88,6 +118,11 @@ config SND_HDA_CODEC_INTELHDMI
 	  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
@@ -99,6 +134,11 @@ 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
@@ -106,6 +146,11 @@ config SND_HDA_CODEC_CMEDIA
 	  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
@@ -113,6 +158,11 @@ config SND_HDA_CODEC_SI3054
 	  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