its level up and down at every change.
-Volume control
---------------
+Volume control (Console Audio control)
+--------------------------------------
procfs: /proc/acpi/ibm/volume
ALSA: "ThinkPad Console Audio Control", default ID: "ThinkPadEC"
Software volume control should be done only in the main AC97/HDA
mixer.
-This feature allows volume control on ThinkPad models with a digital
-volume knob (when available, not all models have it), as well as
-mute/unmute control. The available commands are:
+
+About the ThinkPad Console Audio control:
+
+ThinkPads have a built-in amplifier and muting circuit that drives the
+console headphone and speakers. This circuit is after the main AC97
+or HDA mixer in the audio path, and under exclusive control of the
+firmware.
+
+ThinkPads have three special hotkeys to interact with the console
+audio control: volume up, volume down and mute.
+
+It is worth noting that the normal way the mute function works (on
+ThinkPads that do not have a "mute LED") is:
+
+1. Press mute to mute. It will *always* mute, you can press it as
+ many times as you want, and the sound will remain mute.
+
+2. Press either volume key to unmute the ThinkPad (it will _not_
+ change the volume, it will just unmute).
+
+This is a very superior design when compared to the cheap software-only
+mute-toggle solution found on normal consumer laptops: you can be
+absolutely sure the ThinkPad will not make noise if you press the mute
+button, no matter the previous state.
+
+The IBM ThinkPads, and the earlier Lenovo ThinkPads have variable-gain
+amplifiers driving the speakers and headphone output, and the firmware
+also handles volume control for the headphone and speakers on these
+ThinkPads without any help from the operating system (this volume
+control stage exists after the main AC97 or HDA mixer in the audio
+path).
+
+The newer Lenovo models only have firmware mute control, and depend on
+the main HDA mixer to do volume control (which is done by the operating
+system). In this case, the volume keys are filtered out for unmute
+key press (there are some firmware bugs in this area) and delivered as
+normal key presses to the operating system (thinkpad-acpi is not
+involved).
+
+
+The ThinkPad-ACPI volume control:
+
+The preferred way to interact with the Console Audio control is the
+ALSA interface.
+
+The legacy procfs interface allows one to read the current state,
+and if volume control is enabled, accepts the following commands:
echo up >/proc/acpi/ibm/volume
echo down >/proc/acpi/ibm/volume
echo 'level <level>' >/proc/acpi/ibm/volume
The <level> number range is 0 to 14 although not all of them may be
-distinct. The unmute the volume after the mute command, use either the
+distinct. To unmute the volume after the mute command, use either the
up or down command (the level command will not unmute the volume), or
the unmute command.
-The current volume level and mute state is shown in the file.
-
You can use the volume_capabilities parameter to tell the driver
whether your thinkpad has volume control or mute-only control:
volume_capabilities=1 for mixers with mute and volume control,
This driver was formerly known as ibm-acpi.
+ Extra functionality will be available if the rfkill (CONFIG_RFKILL)
+ and/or ALSA (CONFIG_SND) subsystems are available in the kernel.
+ Note that if you want ThinkPad-ACPI to be built-in instead of
+ modular, ALSA and rfkill will also have to be built-in.
+
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
* 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
-static int alsa_index = SNDRV_DEFAULT_IDX1;
+static int alsa_index = ~((1 << (SNDRV_CARDS - 3)) - 1); /* last three slots */
static char *alsa_id = "ThinkPadEC";
static int alsa_enable = SNDRV_DEFAULT_ENABLE1;
rc = snd_card_create(alsa_index, alsa_id, THIS_MODULE,
sizeof(struct tpacpi_alsa_data), &card);
- if (rc < 0)
- return rc;
- if (!card)
- return -ENOMEM;
+ if (rc < 0 || !card) {
+ printk(TPACPI_ERR
+ "Failed to create ALSA card structures: %d\n", rc);
+ return 1;
+ }
BUG_ON(!card->private_data);
data = card->private_data;
rc = snd_ctl_add(card, ctl_vol);
if (rc < 0) {
printk(TPACPI_ERR
- "Failed to create ALSA volume control\n");
- goto err_out;
+ "Failed to create ALSA volume control: %d\n",
+ rc);
+ goto err_exit;
}
data->ctl_vol_id = &ctl_vol->id;
}
ctl_mute = snd_ctl_new1(&volume_alsa_control_mute, NULL);
rc = snd_ctl_add(card, ctl_mute);
if (rc < 0) {
- printk(TPACPI_ERR "Failed to create ALSA mute control\n");
- goto err_out;
+ printk(TPACPI_ERR "Failed to create ALSA mute control: %d\n",
+ rc);
+ goto err_exit;
}
data->ctl_mute_id = &ctl_mute->id;
snd_card_set_dev(card, &tpacpi_pdev->dev);
rc = snd_card_register(card);
-
-err_out:
if (rc < 0) {
- snd_card_free(card);
- card = NULL;
+ printk(TPACPI_ERR "Failed to register ALSA card: %d\n", rc);
+ goto err_exit;
}
alsa_card = card;
- return rc;
+ return 0;
+
+err_exit:
+ snd_card_free(card);
+ return 1;
}
#define TPACPI_VOL_Q_MUTEONLY 0x0001 /* Mute-only control available */
.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
*/
"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: "
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); \
git://bbs.cooldavid.org / net-next-2.6.git / commitdiff