modem's pcm "two device" config

This defines two modem related pcm devices: "phoneline" is driver's pcm
reference, with "modem" the line will be "Hook-Off"ed automatically.

Signed-off-by: Sasha Khapyorsky <sashak@smlink.com>

src/conf/alsa.conf

@@ -251,6 +251,7 @@ pcm.surround71 cards.pcm.surround71
 pcm.iec958 cards.pcm.iec958
 pcm.spdif cards.pcm.iec958
 pcm.modem cards.pcm.modem
+pcm.phoneline cards.pcm.phoneline
 
 pcm.default cards.pcm.default
 pcm.dmix cards.pcm.dmix

src/conf/pcm/modem.conf

@@ -1,8 +1,8 @@
 #
-# Modem output
+# "raw" modem - phoneline
 #
 
-pcm.!modem {
+pcm.!phoneline {
 	@args [ CARD DEV ]
 	@args.CARD {
 		type string
@@ -45,3 +45,60 @@ pcm.!modem {
 		]
 	}
 }
+
+#
+#  "autohooked" modem
+#
+
+pcm.!modem {
+	@args [ CARD DEV ]
+	@args.CARD {
+		type string
+		default {
+			@func getenv
+			vars [
+				ALSA_MODEM_CARD
+				ALSA_PCM_CARD
+				ALSA_CARD
+			]
+			default {
+				@func refer
+				name defaults.pcm.modem.card
+			}
+		}
+	}
+	@args.DEV {
+		type integer
+		default {
+			@func igetenv
+			vars [
+				ALSA_MODEM_DEVICE
+			]
+			default {
+				@func refer
+				name defaults.pcm.modem.device
+			}
+		}
+	}
+	type hooks
+	slave {
+		pcm {
+			@func concat
+			strings [
+				"cards.pcm.phoneline:CARD=" $CARD ",DEV=" $DEV
+			]
+		}
+	}
+	hooks.0 {
+		type ctl_elems
+		hook_args [
+		{
+			name "Off-hook Switch"
+			preserve true
+			value "on"
+			lock false
+			optional true
+		}
+		]
+	}
+}