thinkpad-acpi: support MUTE-only ThinkPads

Lenovo removed the extra mixer since the T61 and thereabouts.
Newer Lenovo models only have the mute gate function, and leave
the volume control to the HDA mixer.

Until a way to automatically query the firmware about its audio
control capabilities is discovered (there might not be any), use a
white/black list.

We will likely need to ask T60 (old and new model) and Z60/Z61 users
whether they have volume control to populate the black/white list.
Meanwhile, provide a volume_capabilities parameter that can be used to
override the defaults.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Lorne Applebaum <lorne.applebaum@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Documentation/laptops/thinkpad-acpi.txt

@@ -1098,18 +1098,31 @@ Volume control
 procfs: /proc/acpi/ibm/volume
 
 This feature allows volume control on ThinkPad models with a digital
-volume knob, as well as mute/unmute control.  The available commands are:
+volume knob (when available, not all models have it), as well as
+mute/unmute control.  The available commands are:
 
 	echo up   >/proc/acpi/ibm/volume
 	echo down >/proc/acpi/ibm/volume
 	echo mute >/proc/acpi/ibm/volume
+	echo unmute >/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
-up or down command (the level command will not unmute the volume).
+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,
+volume_capabilities=2 for mixers with only mute control.
+
+If the driver misdetects the capabilities for your ThinkPad model,
+please report this to ibm-acpi-devel@lists.sourceforge.net, so that we
+can update the driver.
+
 There are two strategies for volume control.  To select which one
 should be used, use the volume_mode module parameter: volume_mode=1
 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing
@@ -1450,3 +1463,5 @@ Sysfs interface changelog:
 		is deprecated and marked for removal.
 
 0x020600:	Marker for backlight change event support.
+
+0x020700:	Support for mute-only mixers.

drivers/platform/x86/thinkpad_acpi.c

@@ -22,7 +22,7 @@
  */
 
 #define TPACPI_VERSION "0.23"
-#define TPACPI_SYSFS_VERSION 0x020600
+#define TPACPI_SYSFS_VERSION 0x020700
 
 /*
  *  Changelog:
@@ -299,6 +299,7 @@ static struct {
 	u32 fan_ctrl_status_undef:1;
 	u32 second_fan:1;
 	u32 beep_needs_two_args:1;
+	u32 mixer_no_level_control:1;
 	u32 input_device_registered:1;
 	u32 platform_drv_registered:1;
 	u32 platform_drv_attrs_registered:1;
@@ -426,6 +427,12 @@ static void tpacpi_log_usertask(const char * const what)
 	  .ec = TPACPI_MATCH_ANY,		\
 	  .quirks = (__quirk) }
 
+#define TPACPI_QEC_LNV(__id1, __id2, __quirk)	\
+	{ .vendor = PCI_VENDOR_ID_LENOVO,	\
+	  .bios = TPACPI_MATCH_ANY,		\
+	  .ec = TPID(__id1, __id2),		\
+	  .quirks = (__quirk) }
+
 struct tpacpi_quirk {
 	unsigned int vendor;
 	u16 bios;
@@ -6416,9 +6423,17 @@ enum tpacpi_volume_access_mode {
 	TPACPI_VOL_MODE_MAX
 };
 
+enum tpacpi_volume_capabilities {
+	TPACPI_VOL_CAP_AUTO = 0,	/* Use white/blacklist */
+	TPACPI_VOL_CAP_VOLMUTE,		/* Output vol and mute */
+	TPACPI_VOL_CAP_MUTEONLY,	/* Output mute only */
+	TPACPI_VOL_CAP_MAX
+};
+
 static enum tpacpi_volume_access_mode volume_mode =
 	TPACPI_VOL_MODE_MAX;
 
+static enum tpacpi_volume_capabilities volume_capabilities;
 
 /*
  * Used to syncronize writers to TP_EC_AUDIO and
@@ -6430,7 +6445,7 @@ static void tpacpi_volume_checkpoint_nvram(void)
 {
 	u8 lec = 0;
 	u8 b_nvram;
-	const u8 ec_mask = TP_EC_AUDIO_LVL_MSK | TP_EC_AUDIO_MUTESW_MSK;
+	u8 ec_mask;
 
 	if (volume_mode != TPACPI_VOL_MODE_ECNVRAM)
 		return;
@@ -6438,6 +6453,11 @@ static void tpacpi_volume_checkpoint_nvram(void)
 	vdbg_printk(TPACPI_DBG_MIXER,
 		"trying to checkpoint mixer state to NVRAM...\n");
 
+	if (tp_features.mixer_no_level_control)
+		ec_mask = TP_EC_AUDIO_MUTESW_MSK;
+	else
+		ec_mask = TP_EC_AUDIO_MUTESW_MSK | TP_EC_AUDIO_LVL_MSK;
+
 	if (mutex_lock_killable(&volume_mutex) < 0)
 		return;
 
@@ -6575,8 +6595,36 @@ static void volume_exit(void)
 	tpacpi_volume_checkpoint_nvram();
 }
 
+#define TPACPI_VOL_Q_MUTEONLY	0x0001	/* Mute-only control available */
+#define TPACPI_VOL_Q_LEVEL	0x0002  /* Volume control available */
+
+static const struct tpacpi_quirk volume_quirk_table[] __initconst = {
+	/* Whitelist volume level on all IBM by default */
+	{ .vendor = PCI_VENDOR_ID_IBM,
+	  .bios   = TPACPI_MATCH_ANY,
+	  .ec     = TPACPI_MATCH_ANY,
+	  .quirks = TPACPI_VOL_Q_LEVEL },
+
+	/* Lenovo models with volume control (needs confirmation) */
+	TPACPI_QEC_LNV('7', 'C', TPACPI_VOL_Q_LEVEL), /* R60/i */
+	TPACPI_QEC_LNV('7', 'E', TPACPI_VOL_Q_LEVEL), /* R60e/i */
+	TPACPI_QEC_LNV('7', '9', TPACPI_VOL_Q_LEVEL), /* T60/p */
+	TPACPI_QEC_LNV('7', 'B', TPACPI_VOL_Q_LEVEL), /* X60/s */
+	TPACPI_QEC_LNV('7', 'J', TPACPI_VOL_Q_LEVEL), /* X60t */
+	TPACPI_QEC_LNV('7', '7', TPACPI_VOL_Q_LEVEL), /* Z60 */
+	TPACPI_QEC_LNV('7', 'F', TPACPI_VOL_Q_LEVEL), /* Z61 */
+
+	/* Whitelist mute-only on all Lenovo by default */
+	{ .vendor = PCI_VENDOR_ID_LENOVO,
+	  .bios   = TPACPI_MATCH_ANY,
+	  .ec	  = TPACPI_MATCH_ANY,
+	  .quirks = TPACPI_VOL_Q_MUTEONLY }
+};
+
 static int __init volume_init(struct ibm_init_struct *iibm)
 {
+	unsigned long quirks;
+
 	vdbg_printk(TPACPI_DBG_INIT, "initializing volume subdriver\n");
 
 	mutex_init(&volume_mutex);
@@ -6596,6 +6644,36 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 		return 1;
 	}
 
+	if (volume_capabilities >= TPACPI_VOL_CAP_MAX)
+		return -EINVAL;
+
+	quirks = tpacpi_check_quirks(volume_quirk_table,
+				     ARRAY_SIZE(volume_quirk_table));
+
+	switch (volume_capabilities) {
+	case TPACPI_VOL_CAP_AUTO:
+		if (quirks & TPACPI_VOL_Q_MUTEONLY)
+			tp_features.mixer_no_level_control = 1;
+		else if (quirks & TPACPI_VOL_Q_LEVEL)
+			tp_features.mixer_no_level_control = 0;
+		else
+			return 1; /* no mixer */
+		break;
+	case TPACPI_VOL_CAP_VOLMUTE:
+		tp_features.mixer_no_level_control = 0;
+		break;
+	case TPACPI_VOL_CAP_MUTEONLY:
+		tp_features.mixer_no_level_control = 1;
+		break;
+	default:
+		return 1;
+	}
+
+	if (volume_capabilities != TPACPI_VOL_CAP_AUTO)
+		dbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_MIXER,
+				"using user-supplied volume_capabilities=%d\n",
+				volume_capabilities);
+
 	if (volume_mode == TPACPI_VOL_MODE_AUTO ||
 	    volume_mode == TPACPI_VOL_MODE_MAX) {
 		volume_mode = TPACPI_VOL_MODE_ECNVRAM;
@@ -6610,7 +6688,8 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 	}
 
 	vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_MIXER,
-			"volume is supported\n");
+			"mute is supported, volume control is %s\n",
+			str_supported(!tp_features.mixer_no_level_control));
 
 	return 0;
 }
@@ -6623,14 +6702,22 @@ static int volume_read(char *p)
 	if (volume_get_status(&status) < 0) {
 		len += sprintf(p + len, "level:\t\tunreadable\n");
 	} else {
+		if (tp_features.mixer_no_level_control)
+			len += sprintf(p + len, "level:\t\tunsupported\n");
+		else
 			len += sprintf(p + len, "level:\t\t%d\n",
 					status & TP_EC_AUDIO_LVL_MSK);
+
 		len += sprintf(p + len, "mute:\t\t%s\n",
 				onoff(status, TP_EC_AUDIO_MUTESW));
-		len += sprintf(p + len, "commands:\tup, down, mute\n");
+
+		len += sprintf(p + len, "commands:\tunmute, mute\n");
+		if (!tp_features.mixer_no_level_control) {
+			len += sprintf(p + len, "commands:\tup, down\n");
 			len += sprintf(p + len, "commands:\tlevel <level>"
 			       " (<level> is 0-%d)\n", TP_EC_VOLUME_MAX);
 		}
+	}
 
 	return len;
 }
@@ -6651,30 +6738,43 @@ static int volume_write(char *buf)
 	new_mute  = s & TP_EC_AUDIO_MUTESW_MSK;
 
 	while ((cmd = next_cmd(&buf))) {
+		if (!tp_features.mixer_no_level_control) {
 			if (strlencmp(cmd, "up") == 0) {
 				if (new_mute)
 					new_mute = 0;
 				else if (new_level < TP_EC_VOLUME_MAX)
 					new_level++;
+				continue;
 			} else if (strlencmp(cmd, "down") == 0) {
 				if (new_mute)
 					new_mute = 0;
 				else if (new_level > 0)
 					new_level--;
+				continue;
 			} else if (sscanf(cmd, "level %u", &l) == 1 &&
 				   l >= 0 && l <= TP_EC_VOLUME_MAX) {
 					new_level = l;
-		} else if (strlencmp(cmd, "mute") == 0) {
+				continue;
+			}
+		}
+		if (strlencmp(cmd, "mute") == 0)
 			new_mute = TP_EC_AUDIO_MUTESW_MSK;
-		} else
+		else if (strlencmp(cmd, "unmute") == 0)
+			new_mute = 0;
+		else
 			return -EINVAL;
 	}
 
+	if (tp_features.mixer_no_level_control) {
+		tpacpi_disclose_usertask("procfs volume", "%smute\n",
+					new_mute ? "" : "un");
+		rc = volume_set_mute(!!new_mute);
+	} else {
 		tpacpi_disclose_usertask("procfs volume",
 					"%smute and set level to %d\n",
 					new_mute ? "" : "un", new_level);
-
 		rc = volume_set_status(new_mute | new_level);
+	}
 
 	return (rc == -EINTR) ? -ERESTARTSYS : rc;
 }
@@ -8410,6 +8510,11 @@ MODULE_PARM_DESC(volume_mode,
 		 "Selects volume control strategy: "
 		 "0=auto, 1=EC, 2=N/A, 3=EC+NVRAM");
 
+module_param_named(volume_capabilities, volume_capabilities, uint, 0444);
+MODULE_PARM_DESC(volume_capabilities,
+		 "Selects the mixer capabilites: "
+		 "0=auto, 1=volume and mute, 2=mute only");
+
 #define TPACPI_PARAM(feature) \
 	module_param_call(feature, set_ibm_param, NULL, NULL, 0); \
 	MODULE_PARM_DESC(feature, "Simulates thinkpad-acpi procfs command " \