2 files changed, 49 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index ec4faffe6b05..2462dc30b39b 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -233,6 +233,29 @@ config THINKPAD_ACPI
 
           If you have an IBM or Lenovo ThinkPad laptop, say Y or M here.
 
+config THINKPAD_ACPI_ALSA_SUPPORT
+        bool "Console audio control ALSA interface"
+        depends on THINKPAD_ACPI
+        depends on SND
+        depends on SND = y || THINKPAD_ACPI = SND
+        default y
+        ---help---
+          Enables monitoring of the built-in console audio output control
+          (headphone and speakers), which is operated by the mute and (in
+          some ThinkPad models) volume hotkeys.
+
+          If this option is enabled, ThinkPad-ACPI will export an ALSA card
+          with a single read-only mixer control, which should be used for
+          on-screen-display feedback purposes by the Desktop Environment.
+
+          Optionally, the driver will also allow software control (the
+          ALSA mixer will be made read-write).  Please refer to the driver
+          documentation for details.
+
+          All IBM models have both volume and mute control.  Newer Lenovo
+          models only have mute control (the volume hotkeys are just normal
+          keys and volume control is done through the main HDA mixer).
+
 config THINKPAD_ACPI_DEBUGFACILITIES
         bool "Maintainer debug facilities"
         depends on THINKPAD_ACPI
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 9b7da9c96e76..e67e4feb35cb 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6384,6 +6384,8 @@ static struct ibm_struct brightness_driver_data = {
  * and we leave them unchanged.
  */
 
+#ifdef CONFIG_THINKPAD_ACPI_ALSA_SUPPORT
+
 #define TPACPI_ALSA_DRVNAME  "ThinkPad EC"
 #define TPACPI_ALSA_SHRTNAME "ThinkPad Console Audio Control"
 #define TPACPI_ALSA_MIXERNAME TPACPI_ALSA_SHRTNAME
@@ -7021,6 +7023,28 @@ static struct ibm_struct volume_driver_data = {
         .shutdown = volume_shutdown,
 };
 
+#else /* !CONFIG_THINKPAD_ACPI_ALSA_SUPPORT */
+
+#define alsa_card NULL
+
+static void inline volume_alsa_notify_change(void)
+{
+}
+
+static int __init volume_init(struct ibm_init_struct *iibm)
+{
+        printk(TPACPI_INFO
+                "volume: disabled as there is no ALSA support in this kernel\n");
+
+        return 1;
+}
+
+static struct ibm_struct volume_driver_data = {
+        .name = "volume",
+};
+
+#endif /* CONFIG_THINKPAD_ACPI_ALSA_SUPPORT */
+
 /*************************************************************************
  * Fan subdriver
  */
@@ -8743,6 +8767,7 @@ MODULE_PARM_DESC(hotkey_report_mode,
                  "used for backwards compatibility with userspace, "
                  "see documentation");
 
+#ifdef CONFIG_THINKPAD_ACPI_ALSA_SUPPORT
 module_param_named(volume_mode, volume_mode, uint, 0444);
 MODULE_PARM_DESC(volume_mode,
                  "Selects volume control strategy: "
@@ -8765,6 +8790,7 @@ module_param_named(id, alsa_id, charp, 0444);
 MODULE_PARM_DESC(id, "ALSA id for the ACPI EC Mixer");
 module_param_named(enable, alsa_enable, bool, 0444);
 MODULE_PARM_DESC(enable, "Enable the ALSA interface for the ACPI EC Mixer");
+#endif /* CONFIG_THINKPAD_ACPI_ALSA_SUPPORT */
 
 #define TPACPI_PARAM(feature) \
         module_param_call(feature, set_ibm_param, NULL, NULL, 0); \