[PATCH v2 0/5] ALSA: control - add generic LED API

[PATCH v2 0/5] ALSA: control - add generic LED API

[Jaroslav Kysela]

This patchset tries to resolve the diversity in the audio LED
control among the ALSA drivers. A new control layer registration
is introduced which allows to run additional operations on
top of the elementary ALSA sound controls.

A new control access group (three bits in the access flags)
was introduced to carry the LED group information for
the sound controls. The low-level sound drivers can just
mark those controls using this access group. This information
is exported to the user space and eventually the user space
can create sound controls which can belong to a LED group.

The actual state ('route') evaluation is really easy
(the minimal value check for all channels / controls / cards).
If there's more complicated logic for a given hardware,
the card driver may eventually export a new read-only
sound control for the LED group and do the logic itself.

The new LED trigger control code is completely separated
and possibly optional (there's no symbol dependency).
The full code separation allows eventually to move this
LED trigger control to the user space in future.
Actually it replaces the already present functionality
in the kernel space (HDA drivers) and allows a quick adoption
for the recent hardware (SoundWire / ASoC codecs).

# lsmod | grep snd_ctl_led
snd_ctl_led            16384  0

The sound driver implementation is really easy:

1) call snd_ctl_led_request() when control LED layer should be
   automatically activated
   / it calls module_request("snd-ctl-led") on demand /
2) mark all related kcontrols with
	SNDRV_CTL_ELEM_ACCESS_SPK_LED or
	SNDRV_CTL_ELEM_ACCESS_MIC_LED

v2 changes:
  - fix the locking - remove the controls_rwsem read lock
    in the element get (the consistency is already protected
    with the global snd_ctl_led_mutex and possible partial
    value writes are catched with the next value change
    notification callback)
  - rename state to brightness and show the brightness
    unsigned integer value instead the text on/off string
    (sync with the LED core routines)
  - remove snd_ctl_led_hello() function (CI warning)
  - make snd_ctl_led_get_by_access() function static (CI warning)
  - move snd_ctl_layer_rwsem lock before the registraction
    callback call in snd_ctl_register_layer() - optimization
v1:
  - https://lore.kernel.org/alsa-devel/20210211111400.1131020-1-perex@perex.cz/
Original RFC:
  - https://lore.kernel.org/alsa-devel/20210207201157.869972-1-perex@perex.cz/

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Perry Yuan <Perry.Yuan@dell.com>

Jaroslav Kysela (5):
  ALSA: control - introduce snd_ctl_notify_one() helper
  ALSA: control - add layer registration routines
  ALSA: control - add generic LED trigger module as the new control
    layer
  ALSA: HDA - remove the custom implementation for the audio LED trigger
  ALSA: control - add sysfs support to the LED trigger module

 include/sound/control.h         |  27 ++-
 include/uapi/sound/asound.h     |   6 +-
 sound/core/Kconfig              |   6 +
 sound/core/Makefile             |   2 +
 sound/core/control.c            | 173 ++++++++++++---
 sound/core/control_led.c        | 378 ++++++++++++++++++++++++++++++++
 sound/pci/hda/Kconfig           |   4 +-
 sound/pci/hda/hda_codec.c       |  69 +-----
 sound/pci/hda/hda_generic.c     | 162 +++-----------
 sound/pci/hda/hda_generic.h     |  15 +-
 sound/pci/hda/hda_local.h       |  16 +-
 sound/pci/hda/patch_ca0132.c    |   4 +-
 sound/pci/hda/patch_realtek.c   |   2 +-
 sound/pci/hda/patch_sigmatel.c  |   6 +-
 sound/pci/hda/thinkpad_helper.c |   2 +-
 15 files changed, 609 insertions(+), 263 deletions(-)
 create mode 100644 sound/core/control_led.c

-- 
2.29.2

[PATCH v2 1/5] ALSA: control - introduce snd_ctl_notify_one() helper

[Jaroslav Kysela]

This helper is required for the following generic LED mute
patch. The helper also simplifies some other functions.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 include/sound/control.h |  4 +--
 sound/core/control.c    | 68 +++++++++++++++++++++++++++--------------
 2 files changed, 47 insertions(+), 25 deletions(-)

diff --git a/include/sound/control.h b/include/sound/control.h
index 77d9fa10812d..22f3d48163ff 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -115,6 +115,7 @@ typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
 				      unsigned int cmd, unsigned long arg);
 
 void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
+void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kcontrol * kctl, unsigned int ioff);
 
 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
 void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
@@ -123,8 +124,7 @@ int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
 int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
-int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
-			int active);
+int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active);
 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
 struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 
diff --git a/sound/core/control.c b/sound/core/control.c
index 5165741a8400..8a5cedb0a4be 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -181,6 +181,27 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 }
 EXPORT_SYMBOL(snd_ctl_notify);
 
+/**
+ * snd_ctl_notify_one - Send notification to user-space for a control change
+ * @card: the card to send notification
+ * @mask: the event mask, SNDRV_CTL_EVENT_*
+ * @kctl: the pointer with the control instance
+ * @ioff: the additional offset to the control index
+ *
+ * This function calls snd_ctl_notify() and does additional jobs
+ * like LED state changes.
+ */
+void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
+			struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct snd_ctl_elem_id id = kctl->id;
+
+	id.index += ioff;
+	id.numid += ioff;
+	snd_ctl_notify(card, mask, &id);
+}
+EXPORT_SYMBOL(snd_ctl_notify_one);
+
 /**
  * snd_ctl_new - create a new control instance with some elements
  * @kctl: the pointer to store new control instance
@@ -342,7 +363,6 @@ static int __snd_ctl_add_replace(struct snd_card *card,
 {
 	struct snd_ctl_elem_id id;
 	unsigned int idx;
-	unsigned int count;
 	struct snd_kcontrol *old;
 	int err;
 
@@ -376,10 +396,8 @@ static int __snd_ctl_add_replace(struct snd_card *card,
 	kcontrol->id.numid = card->last_numid + 1;
 	card->last_numid += kcontrol->count;
 
-	id = kcontrol->id;
-	count = kcontrol->count;
-	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
-		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
+	for (idx = 0; idx < kcontrol->count; idx++)
+		snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
 
 	return 0;
 }
@@ -462,16 +480,14 @@ EXPORT_SYMBOL(snd_ctl_replace);
  */
 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 {
-	struct snd_ctl_elem_id id;
 	unsigned int idx;
 
 	if (snd_BUG_ON(!card || !kcontrol))
 		return -EINVAL;
 	list_del(&kcontrol->list);
 	card->controls_count -= kcontrol->count;
-	id = kcontrol->id;
-	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
-		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
+	for (idx = 0; idx < kcontrol->count; idx++)
+		snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx);
 	snd_ctl_free_one(kcontrol);
 	return 0;
 }
@@ -584,11 +600,13 @@ int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 	}
 	snd_ctl_build_ioff(id, kctl, index_offset);
-	ret = 1;
+	downgrade_write(&card->controls_rwsem);
+	snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset);
+	up_read(&card->controls_rwsem);
+	return 1;
+
  unlock:
 	up_write(&card->controls_rwsem);
-	if (ret > 0)
-		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
@@ -1110,25 +1128,34 @@ static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 	unsigned int index_offset;
 	int result;
 
+	down_write(&card->controls_rwsem);
 	kctl = snd_ctl_find_id(card, &control->id);
-	if (kctl == NULL)
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
 		return -ENOENT;
+	}
 
 	index_offset = snd_ctl_get_ioff(kctl, &control->id);
 	vd = &kctl->vd[index_offset];
 	if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
 	    (file && vd->owner && vd->owner != file)) {
+		up_write(&card->controls_rwsem);
 		return -EPERM;
 	}
 
 	snd_ctl_build_ioff(&control->id, kctl, index_offset);
 	result = kctl->put(kctl, control);
-	if (result < 0)
+	if (result < 0) {
+		up_write(&card->controls_rwsem);
 		return result;
+	}
 
 	if (result > 0) {
-		struct snd_ctl_elem_id id = control->id;
-		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
+		downgrade_write(&card->controls_rwsem);
+		snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
+		up_read(&card->controls_rwsem);
+	} else {
+		up_write(&card->controls_rwsem);
 	}
 
 	return 0;
@@ -1150,9 +1177,7 @@ static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 	if (result < 0)
 		goto error;
 
-	down_write(&card->controls_rwsem);
 	result = snd_ctl_elem_write(card, file, control);
-	up_write(&card->controls_rwsem);
 	if (result < 0)
 		goto error;
 
@@ -1301,7 +1326,6 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
 {
 	struct user_element *ue = kctl->private_data;
 	unsigned int *container;
-	struct snd_ctl_elem_id id;
 	unsigned int mask = 0;
 	int i;
 	int change;
@@ -1333,10 +1357,8 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
 	ue->tlv_data_size = size;
 
 	mask |= SNDRV_CTL_EVENT_MASK_TLV;
-	for (i = 0; i < kctl->count; ++i) {
-		snd_ctl_build_ioff(&id, kctl, i);
-		snd_ctl_notify(ue->card, mask, &id);
-	}
+	for (i = 0; i < kctl->count; ++i)
+		snd_ctl_notify_one(ue->card, mask, kctl, i);
 
 	return change;
 }
-- 
2.29.2

[PATCH v2 2/5] ALSA: control - add layer registration routines

[Jaroslav Kysela]

The layer registration allows to handle an extra functionality
on top of the control API. It can be used for the audio
LED control for example.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 include/sound/control.h |  12 +++++
 sound/core/control.c    | 104 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 114 insertions(+), 2 deletions(-)

diff --git a/include/sound/control.h b/include/sound/control.h
index 22f3d48163ff..175610bfa8c8 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -108,6 +108,14 @@ struct snd_ctl_file {
 	struct list_head events;	/* waiting events for read */
 };
 
+struct snd_ctl_layer_ops {
+	struct snd_ctl_layer_ops *next;
+	const char *module_name;
+	void (*lregister)(struct snd_card *card);
+	void (*ldisconnect)(struct snd_card *card);
+	void (*lnotify)(struct snd_card *card, unsigned int mask, struct snd_kcontrol *kctl, unsigned int ioff);
+};
+
 #define snd_ctl_file(n) list_entry(n, struct snd_ctl_file, list)
 
 typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
@@ -140,6 +148,10 @@ int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 #define snd_ctl_unregister_ioctl_compat(fcn)
 #endif
 
+int snd_ctl_request_layer(const char *module_name);
+void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
+void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);
+
 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
 
 static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
diff --git a/sound/core/control.c b/sound/core/control.c
index 8a5cedb0a4be..c0a0725ff492 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -28,10 +28,12 @@ struct snd_kctl_ioctl {
 };
 
 static DECLARE_RWSEM(snd_ioctl_rwsem);
+static DECLARE_RWSEM(snd_ctl_layer_rwsem);
 static LIST_HEAD(snd_control_ioctls);
 #ifdef CONFIG_COMPAT
 static LIST_HEAD(snd_control_compat_ioctls);
 #endif
+static struct snd_ctl_layer_ops *snd_ctl_layer;
 
 static int snd_ctl_open(struct inode *inode, struct file *file)
 {
@@ -195,10 +197,15 @@ void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
 			struct snd_kcontrol *kctl, unsigned int ioff)
 {
 	struct snd_ctl_elem_id id = kctl->id;
+	struct snd_ctl_layer_ops *lops;
 
 	id.index += ioff;
 	id.numid += ioff;
 	snd_ctl_notify(card, mask, &id);
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		lops->lnotify(card, mask, kctl, ioff);
+	up_read(&snd_ctl_layer_rwsem);
 }
 EXPORT_SYMBOL(snd_ctl_notify_one);
 
@@ -1997,6 +2004,84 @@ EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
 #define snd_ctl_ioctl_compat	NULL
 #endif
 
+/*
+ * control layers (audio LED etc.)
+ */
+
+/**
+ * snd_ctl_request_layer - request to use the layer
+ * @module_name: Name of the kernel module (NULL == build-in)
+ *
+ * Return an error code when the module cannot be loaded.
+ */
+int snd_ctl_request_layer(const char *module_name)
+{
+	struct snd_ctl_layer_ops *lops;
+
+	if (module_name == NULL)
+		return 0;
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		if (strcmp(lops->module_name, module_name) == 0)
+			break;
+	up_read(&snd_ctl_layer_rwsem);
+	if (lops)
+		return 0;
+	return request_module(module_name);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_request_layer);
+
+/**
+ * snd_ctl_register_layer - register new control layer
+ * @lops: operation structure
+ *
+ * The new layer can track all control elements and do additional
+ * operations on top (like audio LED handling).
+ */
+void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
+{
+	struct snd_card *card;
+	int card_number;
+
+	down_write(&snd_ctl_layer_rwsem);
+	lops->next = snd_ctl_layer;
+	snd_ctl_layer = lops;
+	up_write(&snd_ctl_layer_rwsem);
+	for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
+		card = snd_card_ref(card_number);
+		if (card) {
+			lops->lregister(card);
+			snd_card_unref(card);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(snd_ctl_register_layer);
+
+/**
+ * snd_ctl_disconnect_layer - disconnect control layer
+ * @lops: operation structure
+ *
+ * It is expected that the information about tracked cards
+ * is freed before this call (the disconnect callback is
+ * not called here).
+ */
+void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
+{
+	struct snd_ctl_layer_ops *lops2, *prev_lops2;
+
+	down_write(&snd_ctl_layer_rwsem);
+	for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next)
+		if (lops2 == lops) {
+			if (!prev_lops2)
+				snd_ctl_layer = lops->next;
+			else
+				prev_lops2->next = lops->next;
+			break;
+		}
+	up_write(&snd_ctl_layer_rwsem);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
+
 /*
  *  INIT PART
  */
@@ -2020,9 +2105,18 @@ static const struct file_operations snd_ctl_f_ops =
 static int snd_ctl_dev_register(struct snd_device *device)
 {
 	struct snd_card *card = device->device_data;
+	struct snd_ctl_layer_ops *lops;
+	int err;
 
-	return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
-				   &snd_ctl_f_ops, card, &card->ctl_dev);
+	err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
+				  &snd_ctl_f_ops, card, &card->ctl_dev);
+	if (err < 0)
+		return err;
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		lops->lregister(card);
+	up_read(&snd_ctl_layer_rwsem);
+	return 0;
 }
 
 /*
@@ -2032,6 +2126,7 @@ static int snd_ctl_dev_disconnect(struct snd_device *device)
 {
 	struct snd_card *card = device->device_data;
 	struct snd_ctl_file *ctl;
+	struct snd_ctl_layer_ops *lops;
 	unsigned long flags;
 
 	read_lock_irqsave(&card->ctl_files_rwlock, flags);
@@ -2041,6 +2136,11 @@ static int snd_ctl_dev_disconnect(struct snd_device *device)
 	}
 	read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 
+	down_read(&snd_ctl_layer_rwsem);
+	for (lops = snd_ctl_layer; lops; lops = lops->next)
+		lops->ldisconnect(card);
+	up_read(&snd_ctl_layer_rwsem);
+
 	return snd_unregister_device(&card->ctl_dev);
 }
 
-- 
2.29.2

[PATCH v2 3/5] ALSA: control - add generic LED trigger module as the new control layer

[Jaroslav Kysela]

The recent laptops have usually two LEDs assigned to reflect
the speaker and microphone mute state. This implementation
adds a tiny layer on top of the control API which calculates
the state for those LEDs using the driver callbacks.

Two new access flags are introduced to describe the controls
which affects the audio path settings (an easy code change
for drivers).

The LED resource can be shared with multiple sound cards with
this code. The user space controls may be added to the state
chain on demand, too.

This code should replace the LED code in the HDA driver and
add a possibility to easy extend the other drivers (ASoC
codecs etc.).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 include/sound/control.h     |  11 ++
 include/uapi/sound/asound.h |   6 +-
 sound/core/Kconfig          |   6 +
 sound/core/Makefile         |   2 +
 sound/core/control.c        |   1 +
 sound/core/control_led.c    | 255 ++++++++++++++++++++++++++++++++++++
 6 files changed, 280 insertions(+), 1 deletion(-)
 create mode 100644 sound/core/control_led.c

diff --git a/include/sound/control.h b/include/sound/control.h
index 175610bfa8c8..e88f2651fee0 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -265,6 +265,17 @@ int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
 						void *arg),
 				    void *arg);
 
+/*
+ * Control LED trigger layer
+ */
+#define SND_CTL_LAYER_MODULE_LED	"snd-ctl-led"
+
+#if IS_MODULE(CONFIG_SND_CTL_LED)
+static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
+#else
+static inline int snd_ctl_led_request(void) { return 0; }
+#endif
+
 /*
  * Helper functions for jack-detection controls
  */
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index 535a7229e1d9..a1aff0a8ec31 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -936,7 +936,7 @@ struct snd_timer_tread {
  *                                                                          *
  ****************************************************************************/
 
-#define SNDRV_CTL_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 8)
+#define SNDRV_CTL_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 9)
 
 struct snd_ctl_card_info {
 	int card;			/* card number */
@@ -982,6 +982,10 @@ typedef int __bitwise snd_ctl_elem_iface_t;
 #define SNDRV_CTL_ELEM_ACCESS_INACTIVE		(1<<8)	/* control does actually nothing, but may be updated */
 #define SNDRV_CTL_ELEM_ACCESS_LOCK		(1<<9)	/* write lock */
 #define SNDRV_CTL_ELEM_ACCESS_OWNER		(1<<10)	/* write lock owner */
+#define SNDRV_CTL_ELEM_ACCESS_LED_SHIFT		11
+#define SNDRV_CTL_ELEM_ACCESS_LED_MASK		(7<<11)	/* three bits - LED group */
+#define SNDRV_CTL_ELEM_ACCESS_SPK_LED		(1<<11)	/* speaker (output) LED flag */
+#define SNDRV_CTL_ELEM_ACCESS_MIC_LED		(2<<11)	/* microphone (input) LED flag */
 #define SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK	(1<<28)	/* kernel use a TLV callback */
 #define SNDRV_CTL_ELEM_ACCESS_USER		(1<<29) /* user space element */
 /* bits 30 and 31 are obsoleted (for indirect access) */
diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index a4050f87f230..db2e3c63ff41 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -203,4 +203,10 @@ config SND_DMA_SGBUF
 	def_bool y
 	depends on X86
 
+config SND_CTL_LED
+	tristate
+	select NEW_LEDS if SND_CTL_LED
+	select LEDS_TRIGGERS if SND_CTL_LED
+	select LEDS_TRIGGER_AUDIO if SND_CTL_LED
+
 source "sound/core/seq/Kconfig"
diff --git a/sound/core/Makefile b/sound/core/Makefile
index ee4a4a6b99ba..d774792850f3 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile
@@ -27,6 +27,7 @@ CFLAGS_pcm_native.o := -I$(src)
 
 snd-pcm-dmaengine-objs := pcm_dmaengine.o
 
+snd-ctl-led-objs  := control_led.o
 snd-rawmidi-objs  := rawmidi.o
 snd-timer-objs    := timer.o
 snd-hrtimer-objs  := hrtimer.o
@@ -37,6 +38,7 @@ snd-seq-device-objs := seq_device.o
 snd-compress-objs := compress_offload.o
 
 obj-$(CONFIG_SND) 		+= snd.o
+obj-$(CONFIG_SND_CTL_LED)	+= snd-ctl-led.o
 obj-$(CONFIG_SND_HWDEP)		+= snd-hwdep.o
 obj-$(CONFIG_SND_TIMER)		+= snd-timer.o
 obj-$(CONFIG_SND_HRTIMER)	+= snd-hrtimer.o
diff --git a/sound/core/control.c b/sound/core/control.c
index c0a0725ff492..c9f062fada0a 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -278,6 +278,7 @@ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 		   SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
 		   SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
 		   SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK |
+		   SNDRV_CTL_ELEM_ACCESS_LED_MASK |
 		   SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
 
 	err = snd_ctl_new(&kctl, count, access, NULL);
diff --git a/sound/core/control_led.c b/sound/core/control_led.c
new file mode 100644
index 000000000000..47dfa48253f2
--- /dev/null
+++ b/sound/core/control_led.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  LED state routines for driver control interface
+ *  Copyright (c) 2021 by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/leds.h>
+#include <sound/core.h>
+#include <sound/control.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("ALSA control interface to LED trigger code.");
+MODULE_LICENSE("GPL");
+
+#define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \
+			>> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1)
+
+struct snd_ctl_led {
+	struct list_head list;
+	struct snd_card *card;
+	struct snd_kcontrol *kctl;
+	unsigned int index_offset;
+};
+
+static DEFINE_MUTEX(snd_ctl_led_mutex);
+static struct list_head snd_ctl_led_controls[MAX_LED];
+static bool snd_ctl_led_card_valid[SNDRV_CARDS];
+
+#define UPDATE_ROUTE(route, cb) \
+	do { \
+		int route2 = (cb); \
+		if (route2 >= 0) \
+			route = route < 0 ? route2 : (route | route2); \
+	} while (0)
+
+static inline unsigned int access_to_group(unsigned int access)
+{
+	return ((access & SNDRV_CTL_ELEM_ACCESS_LED_MASK) >>
+				SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1;
+}
+
+static inline unsigned int group_to_access(unsigned int group)
+{
+	return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
+}
+
+static struct list_head *snd_ctl_led_controls_by_access(unsigned int access)
+{
+	unsigned int group = access_to_group(access);
+	if (group >= MAX_LED)
+		return NULL;
+	return &snd_ctl_led_controls[group];
+}
+
+static int snd_ctl_led_get(struct snd_ctl_led *lctl)
+{
+	struct snd_kcontrol *kctl = lctl->kctl;
+	struct snd_ctl_elem_info info;
+	struct snd_ctl_elem_value value;
+	unsigned int i;
+	int result;
+
+	memset(&info, 0, sizeof(info));
+	info.id = kctl->id;
+	info.id.index += lctl->index_offset;
+	info.id.numid += lctl->index_offset;
+	result = kctl->info(kctl, &info);
+	if (result < 0)
+		return -1;
+	memset(&value, 0, sizeof(value));
+	value.id = info.id;
+	result = kctl->get(kctl, &value);
+	if (result < 0)
+		return -1;
+	if (info.type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
+	    info.type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
+		for (i = 0; i < info.count; i++)
+			if (value.value.integer.value[i] != info.value.integer.min)
+				return 1;
+	} else if (info.type == SNDRV_CTL_ELEM_TYPE_INTEGER64) {
+		for (i = 0; i < info.count; i++)
+			if (value.value.integer64.value[i] != info.value.integer64.min)
+				return 1;
+	}
+	return 0;
+}
+
+static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
+				  struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct list_head *controls;
+	struct snd_ctl_led *lctl;
+	enum led_audio led_trigger_type;
+	int route;
+	bool found;
+
+	controls = snd_ctl_led_controls_by_access(access);
+	if (!controls)
+		return;
+	if (access == SNDRV_CTL_ELEM_ACCESS_SPK_LED) {
+		led_trigger_type = LED_AUDIO_MUTE;
+	} else if (access == SNDRV_CTL_ELEM_ACCESS_MIC_LED) {
+		led_trigger_type = LED_AUDIO_MICMUTE;
+	} else {
+		return;
+	}
+	route = -1;
+	found = false;
+	mutex_lock(&snd_ctl_led_mutex);
+	/* the card may not be registered (active) at this point */
+	if (card && !snd_ctl_led_card_valid[card->number]) {
+		mutex_unlock(&snd_ctl_led_mutex);
+		return;
+	}
+	list_for_each_entry(lctl, controls, list) {
+		if (lctl->kctl == kctl && lctl->index_offset == ioff)
+			found = true;
+		UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
+	}
+	if (!found && kctl && card) {
+		lctl = kzalloc(sizeof(*lctl), GFP_KERNEL);
+		if (lctl) {
+			lctl->card = card;
+			lctl->kctl = kctl;
+			lctl->index_offset = ioff;
+			list_add(&lctl->list, controls);
+			UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
+		}
+	}
+	mutex_unlock(&snd_ctl_led_mutex);
+	if (route >= 0)
+		ledtrig_audio_set(led_trigger_type, route ? LED_OFF : LED_ON);
+}
+
+static void snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	struct snd_kcontrol_volatile *vd;
+	struct list_head *controls;
+	struct snd_ctl_led *lctl;
+
+	vd = &kctl->vd[ioff];
+	controls = snd_ctl_led_controls_by_access(vd->access);
+	if (!controls)
+		return;
+	mutex_lock(&snd_ctl_led_mutex);
+	list_for_each_entry(lctl, controls, list)
+		if (lctl->kctl == kctl && lctl->index_offset == ioff) {
+			list_del(&lctl->list);
+			kfree(lctl);
+			break;
+		}
+	mutex_unlock(&snd_ctl_led_mutex);
+}
+
+static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask,
+			       struct snd_kcontrol *kctl, unsigned int ioff)
+{
+	if (mask == SNDRV_CTL_EVENT_MASK_REMOVE) {
+		snd_ctl_led_remove(kctl, ioff);
+	} else if ((mask & (SNDRV_CTL_EVENT_MASK_INFO |
+			    SNDRV_CTL_EVENT_MASK_ADD |
+			    SNDRV_CTL_EVENT_MASK_VALUE)) != 0) {
+		struct snd_kcontrol_volatile *vd = &kctl->vd[ioff];
+		unsigned int access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
+		if (access)
+			snd_ctl_led_set_state(card, access, kctl, ioff);
+		else if ((mask & SNDRV_CTL_EVENT_MASK_INFO) != 0)
+			snd_ctl_led_remove(kctl, ioff);
+	}
+}
+
+static void snd_ctl_led_refresh(void)
+{
+	unsigned int group;
+
+	for (group = 0; group < MAX_LED; group++)
+		snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
+}
+
+static void snd_ctl_led_clean(struct snd_card *card)
+{
+	unsigned int group;
+	struct list_head *controls;
+	struct snd_ctl_led *lctl;
+
+	for (group = 0; group < MAX_LED; group++) {
+		controls = &snd_ctl_led_controls[group];
+repeat:
+		list_for_each_entry(lctl, controls, list)
+			if (!card || lctl->card == card) {
+				list_del(&lctl->list);
+				kfree(lctl);
+				goto repeat;
+			}
+	}
+}
+
+static void snd_ctl_led_register(struct snd_card *card)
+{
+	struct snd_kcontrol *kctl;
+	unsigned int ioff;
+
+	if (snd_BUG_ON(card->number < 0 ||
+		       card->number >= ARRAY_SIZE(snd_ctl_led_card_valid)))
+		return;
+	mutex_lock(&snd_ctl_led_mutex);
+	snd_ctl_led_card_valid[card->number] = true;
+	mutex_unlock(&snd_ctl_led_mutex);
+	down_read(&card->controls_rwsem);
+	list_for_each_entry(kctl, &card->controls, list)
+		for (ioff = 0; ioff < kctl->count; ioff++)
+			snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
+	up_read(&card->controls_rwsem);
+	snd_ctl_led_refresh();
+}
+
+static void snd_ctl_led_disconnect(struct snd_card *card)
+{
+	mutex_lock(&snd_ctl_led_mutex);
+	snd_ctl_led_card_valid[card->number] = false;
+	snd_ctl_led_clean(card);
+	mutex_unlock(&snd_ctl_led_mutex);
+	snd_ctl_led_refresh();
+}
+
+/*
+ * Control layer registration
+ */
+static struct snd_ctl_layer_ops snd_ctl_led_lops = {
+	.module_name = SND_CTL_LAYER_MODULE_LED,
+	.lregister = snd_ctl_led_register,
+	.ldisconnect = snd_ctl_led_disconnect,
+	.lnotify = snd_ctl_led_notify,
+};
+
+static int __init snd_ctl_led_init(void)
+{
+	unsigned int group;
+
+	for (group = 0; group < MAX_LED; group++)
+		INIT_LIST_HEAD(&snd_ctl_led_controls[group]);
+	snd_ctl_register_layer(&snd_ctl_led_lops);
+	return 0;
+}
+
+static void __exit snd_ctl_led_exit(void)
+{
+	snd_ctl_disconnect_layer(&snd_ctl_led_lops);
+	snd_ctl_led_clean(NULL);
+}
+
+module_init(snd_ctl_led_init)
+module_exit(snd_ctl_led_exit)
-- 
2.29.2

[PATCH v2 4/5] ALSA: HDA - remove the custom implementation for the audio LED trigger

[Jaroslav Kysela]

With the new snd-ctl-led module, we have a generic way
to trigger audio LEDs based on the sound control changes.

Remove the custom implementation from the HDA driver.

Move the LED initialization before snd_hda_gen_parse_auto_config()
call in all drivers to create marked controls there.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/pci/hda/Kconfig           |   4 +-
 sound/pci/hda/hda_codec.c       |  69 ++------------
 sound/pci/hda/hda_generic.c     | 162 +++++---------------------------
 sound/pci/hda/hda_generic.h     |  15 +--
 sound/pci/hda/hda_local.h       |  16 +---
 sound/pci/hda/patch_ca0132.c    |   4 +-
 sound/pci/hda/patch_realtek.c   |   2 +-
 sound/pci/hda/patch_sigmatel.c  |   6 +-
 sound/pci/hda/thinkpad_helper.c |   2 +-
 9 files changed, 45 insertions(+), 235 deletions(-)

diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
index 90759391cbac..c4360cdbc728 100644
--- a/sound/pci/hda/Kconfig
+++ b/sound/pci/hda/Kconfig
@@ -221,10 +221,8 @@ comment "Set to Y if you want auto-loading the codec driver"
 
 config SND_HDA_GENERIC
 	tristate "Enable generic HD-audio codec parser"
-	select NEW_LEDS if SND_HDA_GENERIC_LEDS
+	select SND_CTL_LED if SND_HDA_GENERIC_LEDS
 	select LEDS_CLASS if SND_HDA_GENERIC_LEDS
-	select LEDS_TRIGGERS if SND_HDA_GENERIC_LEDS
-	select LEDS_TRIGGER_AUDIO if SND_HDA_GENERIC_LEDS
 	help
 	  Say Y or M here to enable the generic HD-audio codec parser
 	  in snd-hda-intel driver.
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 9b755062d841..961750b4d56f 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1952,7 +1952,7 @@ static int add_follower(struct hda_codec *codec,
 int __snd_hda_add_vmaster(struct hda_codec *codec, char *name,
 			  unsigned int *tlv, const char * const *followers,
 			  const char *suffix, bool init_follower_vol,
-			  struct snd_kcontrol **ctl_ret)
+			  unsigned int access, struct snd_kcontrol **ctl_ret)
 {
 	struct snd_kcontrol *kctl;
 	int err;
@@ -1968,6 +1968,7 @@ int __snd_hda_add_vmaster(struct hda_codec *codec, char *name,
 	kctl = snd_ctl_make_virtual_master(name, tlv);
 	if (!kctl)
 		return -ENOMEM;
+	kctl->vd[0].access |= access;
 	err = snd_hda_ctl_add(codec, 0, kctl);
 	if (err < 0)
 		return err;
@@ -1994,87 +1995,29 @@ int __snd_hda_add_vmaster(struct hda_codec *codec, char *name,
 }
 EXPORT_SYMBOL_GPL(__snd_hda_add_vmaster);
 
-/*
- * mute-LED control using vmaster
- */
-static int vmaster_mute_mode_info(struct snd_kcontrol *kcontrol,
-				  struct snd_ctl_elem_info *uinfo)
-{
-	static const char * const texts[] = {
-		"On", "Off", "Follow Master"
-	};
-
-	return snd_ctl_enum_info(uinfo, 1, 3, texts);
-}
-
-static int vmaster_mute_mode_get(struct snd_kcontrol *kcontrol,
-				 struct snd_ctl_elem_value *ucontrol)
-{
-	struct hda_vmaster_mute_hook *hook = snd_kcontrol_chip(kcontrol);
-	ucontrol->value.enumerated.item[0] = hook->mute_mode;
-	return 0;
-}
-
-static int vmaster_mute_mode_put(struct snd_kcontrol *kcontrol,
-				 struct snd_ctl_elem_value *ucontrol)
-{
-	struct hda_vmaster_mute_hook *hook = snd_kcontrol_chip(kcontrol);
-	unsigned int old_mode = hook->mute_mode;
-
-	hook->mute_mode = ucontrol->value.enumerated.item[0];
-	if (hook->mute_mode > HDA_VMUTE_FOLLOW_MASTER)
-		hook->mute_mode = HDA_VMUTE_FOLLOW_MASTER;
-	if (old_mode == hook->mute_mode)
-		return 0;
-	snd_hda_sync_vmaster_hook(hook);
-	return 1;
-}
-
-static const struct snd_kcontrol_new vmaster_mute_mode = {
-	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
-	.name = "Mute-LED Mode",
-	.info = vmaster_mute_mode_info,
-	.get = vmaster_mute_mode_get,
-	.put = vmaster_mute_mode_put,
-};
-
 /* meta hook to call each driver's vmaster hook */
 static void vmaster_hook(void *private_data, int enabled)
 {
 	struct hda_vmaster_mute_hook *hook = private_data;
 
-	if (hook->mute_mode != HDA_VMUTE_FOLLOW_MASTER)
-		enabled = hook->mute_mode;
 	hook->hook(hook->codec, enabled);
 }
 
 /**
- * snd_hda_add_vmaster_hook - Add a vmaster hook for mute-LED
+ * snd_hda_add_vmaster_hook - Add a vmaster hw specific hook
  * @codec: the HDA codec
  * @hook: the vmaster hook object
- * @expose_enum_ctl: flag to create an enum ctl
  *
- * Add a mute-LED hook with the given vmaster switch kctl.
- * When @expose_enum_ctl is set, "Mute-LED Mode" control is automatically
- * created and associated with the given hook.
+ * Add a hw specific hook (like EAPD) with the given vmaster switch kctl.
  */
 int snd_hda_add_vmaster_hook(struct hda_codec *codec,
-			     struct hda_vmaster_mute_hook *hook,
-			     bool expose_enum_ctl)
+			     struct hda_vmaster_mute_hook *hook)
 {
-	struct snd_kcontrol *kctl;
-
 	if (!hook->hook || !hook->sw_kctl)
 		return 0;
 	hook->codec = codec;
-	hook->mute_mode = HDA_VMUTE_FOLLOW_MASTER;
 	snd_ctl_add_vmaster_hook(hook->sw_kctl, vmaster_hook, hook);
-	if (!expose_enum_ctl)
-		return 0;
-	kctl = snd_ctl_new1(&vmaster_mute_mode, hook);
-	if (!kctl)
-		return -ENOMEM;
-	return snd_hda_ctl_add(codec, 0, kctl);
+	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_hda_add_vmaster_hook);
 
diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
index 5e40944e7342..d1979ec39d3e 100644
--- a/sound/pci/hda/hda_generic.c
+++ b/sound/pci/hda/hda_generic.c
@@ -981,6 +981,8 @@ add_control(struct hda_gen_spec *spec, int type, const char *name,
 	knew->index = cidx;
 	if (get_amp_nid_(val))
 		knew->subdevice = HDA_SUBDEV_AMP_FLAG;
+	if (knew->access == 0)
+		knew->access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
 	knew->private_value = val;
 	return knew;
 }
@@ -3618,8 +3620,11 @@ static int add_single_cap_ctl(struct hda_codec *codec, const char *label,
 			   amp_val_replace_channels(ctl, chs));
 	if (!knew)
 		return -ENOMEM;
-	if (is_switch)
+	if (is_switch) {
 		knew->put = cap_single_sw_put;
+		if (spec->mic_mute_led)
+			knew->access |= SNDRV_CTL_ELEM_ACCESS_MIC_LED;
+	}
 	if (!inv_dmic)
 		return 0;
 
@@ -3634,8 +3639,11 @@ static int add_single_cap_ctl(struct hda_codec *codec, const char *label,
 			   amp_val_replace_channels(ctl, 2));
 	if (!knew)
 		return -ENOMEM;
-	if (is_switch)
+	if (is_switch) {
 		knew->put = cap_single_sw_put;
+		if (spec->mic_mute_led)
+			knew->access |= SNDRV_CTL_ELEM_ACCESS_MIC_LED;
+	}
 	return 0;
 }
 
@@ -3676,6 +3684,8 @@ static int create_bind_cap_vol_ctl(struct hda_codec *codec, int idx,
 		knew->index = idx;
 		knew->private_value = sw_ctl;
 		knew->subdevice = HDA_SUBDEV_AMP_FLAG;
+		if (spec->mic_mute_led)
+			knew->access |= SNDRV_CTL_ELEM_ACCESS_MIC_LED;
 	}
 	return 0;
 }
@@ -3917,11 +3927,6 @@ static int create_mute_led_cdev(struct hda_codec *codec,
 	return devm_led_classdev_register(&codec->core.dev, cdev);
 }
 
-static void vmaster_update_mute_led(void *private_data, int enabled)
-{
-	ledtrig_audio_set(LED_AUDIO_MUTE, enabled ? LED_OFF : LED_ON);
-}
-
 /**
  * snd_dha_gen_add_mute_led_cdev - Create a LED classdev and enable as vmaster mute LED
  * @codec: the HDA codec
@@ -3945,134 +3950,11 @@ int snd_hda_gen_add_mute_led_cdev(struct hda_codec *codec,
 	if (spec->vmaster_mute.hook)
 		codec_err(codec, "vmaster hook already present before cdev!\n");
 
-	spec->vmaster_mute.hook = vmaster_update_mute_led;
-	spec->vmaster_mute_enum = 1;
+	spec->vmaster_mute_led = 1;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_hda_gen_add_mute_led_cdev);
 
-/*
- * mic mute LED hook helpers
- */
-enum {
-	MICMUTE_LED_ON,
-	MICMUTE_LED_OFF,
-	MICMUTE_LED_FOLLOW_CAPTURE,
-	MICMUTE_LED_FOLLOW_MUTE,
-};
-
-static void call_micmute_led_update(struct hda_codec *codec)
-{
-	struct hda_gen_spec *spec = codec->spec;
-	unsigned int val;
-
-	switch (spec->micmute_led.led_mode) {
-	case MICMUTE_LED_ON:
-		val = 1;
-		break;
-	case MICMUTE_LED_OFF:
-		val = 0;
-		break;
-	case MICMUTE_LED_FOLLOW_CAPTURE:
-		val = !!spec->micmute_led.capture;
-		break;
-	case MICMUTE_LED_FOLLOW_MUTE:
-	default:
-		val = !spec->micmute_led.capture;
-		break;
-	}
-
-	if (val == spec->micmute_led.led_value)
-		return;
-	spec->micmute_led.led_value = val;
-	ledtrig_audio_set(LED_AUDIO_MICMUTE,
-			  spec->micmute_led.led_value ? LED_ON : LED_OFF);
-}
-
-static void update_micmute_led(struct hda_codec *codec,
-			       struct snd_kcontrol *kcontrol,
-			       struct snd_ctl_elem_value *ucontrol)
-{
-	struct hda_gen_spec *spec = codec->spec;
-	unsigned int mask;
-
-	if (spec->micmute_led.old_hook)
-		spec->micmute_led.old_hook(codec, kcontrol, ucontrol);
-
-	if (!ucontrol)
-		return;
-	mask = 1U << snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
-	if (!strcmp("Capture Switch", ucontrol->id.name)) {
-		/* TODO: How do I verify if it's a mono or stereo here? */
-		if (ucontrol->value.integer.value[0] ||
-		    ucontrol->value.integer.value[1])
-			spec->micmute_led.capture |= mask;
-		else
-			spec->micmute_led.capture &= ~mask;
-		call_micmute_led_update(codec);
-	}
-}
-
-static int micmute_led_mode_info(struct snd_kcontrol *kcontrol,
-				 struct snd_ctl_elem_info *uinfo)
-{
-	static const char * const texts[] = {
-		"On", "Off", "Follow Capture", "Follow Mute",
-	};
-
-	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
-}
-
-static int micmute_led_mode_get(struct snd_kcontrol *kcontrol,
-				struct snd_ctl_elem_value *ucontrol)
-{
-	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
-	struct hda_gen_spec *spec = codec->spec;
-
-	ucontrol->value.enumerated.item[0] = spec->micmute_led.led_mode;
-	return 0;
-}
-
-static int micmute_led_mode_put(struct snd_kcontrol *kcontrol,
-				struct snd_ctl_elem_value *ucontrol)
-{
-	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
-	struct hda_gen_spec *spec = codec->spec;
-	unsigned int mode;
-
-	mode = ucontrol->value.enumerated.item[0];
-	if (mode > MICMUTE_LED_FOLLOW_MUTE)
-		mode = MICMUTE_LED_FOLLOW_MUTE;
-	if (mode == spec->micmute_led.led_mode)
-		return 0;
-	spec->micmute_led.led_mode = mode;
-	call_micmute_led_update(codec);
-	return 1;
-}
-
-static const struct snd_kcontrol_new micmute_led_mode_ctl = {
-	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
-	.name = "Mic Mute-LED Mode",
-	.info = micmute_led_mode_info,
-	.get = micmute_led_mode_get,
-	.put = micmute_led_mode_put,
-};
-
-/* Set up the capture sync hook for controlling the mic-mute LED */
-static int add_micmute_led_hook(struct hda_codec *codec)
-{
-	struct hda_gen_spec *spec = codec->spec;
-
-	spec->micmute_led.led_mode = MICMUTE_LED_FOLLOW_MUTE;
-	spec->micmute_led.capture = 0;
-	spec->micmute_led.led_value = 0;
-	spec->micmute_led.old_hook = spec->cap_sync_hook;
-	spec->cap_sync_hook = update_micmute_led;
-	if (!snd_hda_gen_add_kctl(spec, NULL, &micmute_led_mode_ctl))
-		return -ENOMEM;
-	return 0;
-}
-
 /**
  * snd_dha_gen_add_micmute_led_cdev - Create a LED classdev and enable as mic-mute LED
  * @codec: the HDA codec
@@ -4091,6 +3973,7 @@ int snd_hda_gen_add_micmute_led_cdev(struct hda_codec *codec,
 				     int (*callback)(struct led_classdev *,
 						     enum led_brightness))
 {
+	struct hda_gen_spec *spec = codec->spec;
 	int err;
 
 	if (callback) {
@@ -4101,7 +3984,8 @@ int snd_hda_gen_add_micmute_led_cdev(struct hda_codec *codec,
 		}
 	}
 
-	return add_micmute_led_hook(codec);
+	spec->mic_mute_led = 1;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_hda_gen_add_micmute_led_cdev);
 #endif /* CONFIG_SND_HDA_GENERIC_LEDS */
@@ -5060,6 +4944,9 @@ int snd_hda_gen_parse_auto_config(struct hda_codec *codec,
 
 	parse_user_hints(codec);
 
+	if (spec->vmaster_mute_led || spec->mic_mute_led)
+		snd_ctl_led_request();
+
 	if (spec->mixer_nid && !spec->mixer_merge_nid)
 		spec->mixer_merge_nid = spec->mixer_nid;
 
@@ -5291,7 +5178,7 @@ int snd_hda_gen_build_controls(struct hda_codec *codec)
 	    !snd_hda_find_mixer_ctl(codec, "Master Playback Volume")) {
 		err = snd_hda_add_vmaster(codec, "Master Playback Volume",
 					  spec->vmaster_tlv, follower_pfxs,
-					  "Playback Volume");
+					  "Playback Volume", 0);
 		if (err < 0)
 			return err;
 	}
@@ -5299,13 +5186,14 @@ int snd_hda_gen_build_controls(struct hda_codec *codec)
 	    !snd_hda_find_mixer_ctl(codec, "Master Playback Switch")) {
 		err = __snd_hda_add_vmaster(codec, "Master Playback Switch",
 					    NULL, follower_pfxs,
-					    "Playback Switch",
-					    true, &spec->vmaster_mute.sw_kctl);
+					    "Playback Switch", true,
+					    spec->vmaster_mute_led ?
+						SNDRV_CTL_ELEM_ACCESS_SPK_LED : 0,
+					    &spec->vmaster_mute.sw_kctl);
 		if (err < 0)
 			return err;
 		if (spec->vmaster_mute.hook) {
-			snd_hda_add_vmaster_hook(codec, &spec->vmaster_mute,
-						 spec->vmaster_mute_enum);
+			snd_hda_add_vmaster_hook(codec, &spec->vmaster_mute);
 			snd_hda_sync_vmaster_hook(&spec->vmaster_mute);
 		}
 	}
diff --git a/sound/pci/hda/hda_generic.h b/sound/pci/hda/hda_generic.h
index 0886bc81f40b..d4dd1b8a2e7e 100644
--- a/sound/pci/hda/hda_generic.h
+++ b/sound/pci/hda/hda_generic.h
@@ -84,15 +84,6 @@ struct badness_table {
 extern const struct badness_table hda_main_out_badness;
 extern const struct badness_table hda_extra_out_badness;
 
-struct hda_micmute_hook {
-	unsigned int led_mode;
-	unsigned int capture;
-	unsigned int led_value;
-	void (*old_hook)(struct hda_codec *codec,
-			 struct snd_kcontrol *kcontrol,
-			 struct snd_ctl_elem_value *ucontrol);
-};
-
 struct hda_gen_spec {
 	char stream_name_analog[32];	/* analog PCM stream */
 	const struct hda_pcm_stream *stream_analog_playback;
@@ -229,7 +220,8 @@ struct hda_gen_spec {
 	unsigned int inv_dmic_split:1; /* inverted dmic w/a for conexant */
 	unsigned int own_eapd_ctl:1; /* set EAPD by own function */
 	unsigned int keep_eapd_on:1; /* don't turn off EAPD automatically */
-	unsigned int vmaster_mute_enum:1; /* add vmaster mute mode enum */
+	unsigned int vmaster_mute_led:1; /* add SPK-LED flag to vmaster mute switch */
+	unsigned int mic_mute_led:1; /* add MIC-LED flag to capture mute switch */
 	unsigned int indep_hp:1; /* independent HP supported */
 	unsigned int prefer_hp_amp:1; /* enable HP amp for speaker if any */
 	unsigned int add_stereo_mix_input:2; /* add aamix as a capture src */
@@ -285,9 +277,6 @@ struct hda_gen_spec {
 			      struct snd_kcontrol *kcontrol,
 			      struct snd_ctl_elem_value *ucontrol);
 
-	/* mic mute LED hook; called via cap_sync_hook */
-	struct hda_micmute_hook micmute_led;
-
 	/* PCM hooks */
 	void (*pcm_playback_hook)(struct hda_pcm_stream *hinfo,
 				  struct hda_codec *codec,
diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index 5beb8aa44ecd..06d4486a4961 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -131,21 +131,15 @@ struct snd_kcontrol *snd_hda_find_mixer_ctl(struct hda_codec *codec,
 int __snd_hda_add_vmaster(struct hda_codec *codec, char *name,
 			  unsigned int *tlv, const char * const *followers,
 			  const char *suffix, bool init_follower_vol,
-			  struct snd_kcontrol **ctl_ret);
-#define snd_hda_add_vmaster(codec, name, tlv, followers, suffix) \
-	__snd_hda_add_vmaster(codec, name, tlv, followers, suffix, true, NULL)
+			  unsigned int access, struct snd_kcontrol **ctl_ret);
+#define snd_hda_add_vmaster(codec, name, tlv, followers, suffix, access) \
+	__snd_hda_add_vmaster(codec, name, tlv, followers, suffix, true, access, NULL)
 int snd_hda_codec_reset(struct hda_codec *codec);
 void snd_hda_codec_register(struct hda_codec *codec);
 void snd_hda_codec_cleanup_for_unbind(struct hda_codec *codec);
 
 #define snd_hda_regmap_sync(codec)	snd_hdac_regmap_sync(&(codec)->core)
 
-enum {
-	HDA_VMUTE_OFF,
-	HDA_VMUTE_ON,
-	HDA_VMUTE_FOLLOW_MASTER,
-};
-
 struct hda_vmaster_mute_hook {
 	/* below two fields must be filled by the caller of
 	 * snd_hda_add_vmaster_hook() beforehand
@@ -153,13 +147,11 @@ struct hda_vmaster_mute_hook {
 	struct snd_kcontrol *sw_kctl;
 	void (*hook)(void *, int);
 	/* below are initialized automatically */
-	unsigned int mute_mode; /* HDA_VMUTE_XXX */
 	struct hda_codec *codec;
 };
 
 int snd_hda_add_vmaster_hook(struct hda_codec *codec,
-			     struct hda_vmaster_mute_hook *hook,
-			     bool expose_enum_ctl);
+			     struct hda_vmaster_mute_hook *hook);
 void snd_hda_sync_vmaster_hook(struct hda_vmaster_mute_hook *hook);
 
 /* amp value bits */
diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 7e62aed172a9..bbcef0869a59 100644
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -7041,11 +7041,11 @@ static int ca0132_build_controls(struct hda_codec *codec)
 					spec->tlv);
 		snd_hda_add_vmaster(codec, "Master Playback Volume",
 					spec->tlv, ca0132_alt_follower_pfxs,
-					"Playback Volume");
+					"Playback Volume", 0);
 		err = __snd_hda_add_vmaster(codec, "Master Playback Switch",
 					    NULL, ca0132_alt_follower_pfxs,
 					    "Playback Switch",
-					    true, &spec->vmaster_mute.sw_kctl);
+					    true, 0, &spec->vmaster_mute.sw_kctl);
 		if (err < 0)
 			return err;
 	}
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 52907506e16e..bc1b268a5289 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -292,7 +292,7 @@ static void alc_fixup_gpio4(struct hda_codec *codec,
 static void alc_fixup_micmute_led(struct hda_codec *codec,
 				  const struct hda_fixup *fix, int action)
 {
-	if (action == HDA_FIXUP_ACT_PROBE)
+	if (action == HDA_FIXUP_ACT_PRE_PROBE)
 		snd_hda_gen_add_micmute_led_cdev(codec, NULL);
 }
 
diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
index c662431bf13a..3bd592e126a3 100644
--- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -4277,6 +4277,9 @@ static int stac_parse_auto_config(struct hda_codec *codec)
 
 	spec->gen.automute_hook = stac_update_outputs;
 
+	if (spec->gpio_led)
+		snd_hda_gen_add_mute_led_cdev(codec, stac_vmaster_hook);
+
 	err = snd_hda_gen_parse_auto_config(codec, &spec->gen.autocfg);
 	if (err < 0)
 		return err;
@@ -4318,9 +4321,6 @@ static int stac_parse_auto_config(struct hda_codec *codec)
 	}
 #endif
 
-	if (spec->gpio_led)
-		snd_hda_gen_add_mute_led_cdev(codec, stac_vmaster_hook);
-
 	if (spec->aloopback_ctl &&
 	    snd_hda_get_bool_hint(codec, "loopback") == 1) {
 		unsigned int wr_verb =
diff --git a/sound/pci/hda/thinkpad_helper.c b/sound/pci/hda/thinkpad_helper.c
index 6698ae241efc..de4d8deed102 100644
--- a/sound/pci/hda/thinkpad_helper.c
+++ b/sound/pci/hda/thinkpad_helper.c
@@ -18,7 +18,7 @@ static bool is_thinkpad(struct hda_codec *codec)
 static void hda_fixup_thinkpad_acpi(struct hda_codec *codec,
 				    const struct hda_fixup *fix, int action)
 {
-	if (action == HDA_FIXUP_ACT_PROBE) {
+	if (action == HDA_FIXUP_ACT_PRE_PROBE) {
 		if (!is_thinkpad(codec))
 			return;
 		snd_hda_gen_add_mute_led_cdev(codec, NULL);
-- 
2.29.2

[PATCH v2 5/5] ALSA: control - add sysfs support to the LED trigger module

[Jaroslav Kysela]

Create SYSFS/devices/virtual/sound/ctl-led tree
(with SYSFS/class/sound/ctl-led symlink).

  speaker/
    +-- mode
    +-- brightness
  mic/
    +-- mode
    +-- brightness

Copy the idea from the HDA driver and allow to set the audio
LEDs based on the various modes:

- follow mute
- follow moute (inverted to follow mute)
- off
- on

Also, the actual LED state is exposed.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 sound/core/control_led.c | 183 ++++++++++++++++++++++++++++++++-------
 1 file changed, 153 insertions(+), 30 deletions(-)

diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index 47dfa48253f2..cafe4c82ca35 100644
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -17,7 +17,23 @@ MODULE_LICENSE("GPL");
 #define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \
 			>> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1)
 
+enum snd_ctl_led_mode {
+	 MODE_FOLLOW_MUTE = 0,
+	 MODE_FOLLOW_ROUTE,
+	 MODE_OFF,
+	 MODE_ON,
+};
+
 struct snd_ctl_led {
+	struct device dev;
+	struct list_head controls;
+	const char *name;
+	unsigned int group;
+	enum led_audio trigger_type;
+	enum snd_ctl_led_mode mode;
+};
+
+struct snd_ctl_led_ctl {
 	struct list_head list;
 	struct snd_card *card;
 	struct snd_kcontrol *kctl;
@@ -25,8 +41,21 @@ struct snd_ctl_led {
 };
 
 static DEFINE_MUTEX(snd_ctl_led_mutex);
-static struct list_head snd_ctl_led_controls[MAX_LED];
 static bool snd_ctl_led_card_valid[SNDRV_CARDS];
+static struct snd_ctl_led snd_ctl_leds[MAX_LED] = {
+	{
+		.name = "speaker",
+		.group = (SNDRV_CTL_ELEM_ACCESS_SPK_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
+		.trigger_type = LED_AUDIO_MUTE,
+		.mode = MODE_FOLLOW_MUTE,
+	},
+	{
+		.name = "mic",
+		.group = (SNDRV_CTL_ELEM_ACCESS_MIC_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
+		.trigger_type = LED_AUDIO_MICMUTE,
+		.mode = MODE_FOLLOW_MUTE,
+	},
+};
 
 #define UPDATE_ROUTE(route, cb) \
 	do { \
@@ -46,15 +75,15 @@ static inline unsigned int group_to_access(unsigned int group)
 	return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
 }
 
-static struct list_head *snd_ctl_led_controls_by_access(unsigned int access)
+static struct snd_ctl_led *snd_ctl_led_get_by_access(unsigned int access)
 {
 	unsigned int group = access_to_group(access);
 	if (group >= MAX_LED)
 		return NULL;
-	return &snd_ctl_led_controls[group];
+	return &snd_ctl_leds[group];
 }
 
-static int snd_ctl_led_get(struct snd_ctl_led *lctl)
+static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
 {
 	struct snd_kcontrol *kctl = lctl->kctl;
 	struct snd_ctl_elem_info info;
@@ -90,22 +119,14 @@ static int snd_ctl_led_get(struct snd_ctl_led *lctl)
 static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
 				  struct snd_kcontrol *kctl, unsigned int ioff)
 {
-	struct list_head *controls;
-	struct snd_ctl_led *lctl;
-	enum led_audio led_trigger_type;
+	struct snd_ctl_led *led;
+	struct snd_ctl_led_ctl *lctl;
 	int route;
 	bool found;
 
-	controls = snd_ctl_led_controls_by_access(access);
-	if (!controls)
+	led = snd_ctl_led_get_by_access(access);
+	if (!led)
 		return;
-	if (access == SNDRV_CTL_ELEM_ACCESS_SPK_LED) {
-		led_trigger_type = LED_AUDIO_MUTE;
-	} else if (access == SNDRV_CTL_ELEM_ACCESS_MIC_LED) {
-		led_trigger_type = LED_AUDIO_MICMUTE;
-	} else {
-		return;
-	}
 	route = -1;
 	found = false;
 	mutex_lock(&snd_ctl_led_mutex);
@@ -114,7 +135,7 @@ static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
 		mutex_unlock(&snd_ctl_led_mutex);
 		return;
 	}
-	list_for_each_entry(lctl, controls, list) {
+	list_for_each_entry(lctl, &led->controls, list) {
 		if (lctl->kctl == kctl && lctl->index_offset == ioff)
 			found = true;
 		UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
@@ -125,27 +146,33 @@ static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
 			lctl->card = card;
 			lctl->kctl = kctl;
 			lctl->index_offset = ioff;
-			list_add(&lctl->list, controls);
+			list_add(&lctl->list, &led->controls);
 			UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
 		}
 	}
 	mutex_unlock(&snd_ctl_led_mutex);
+	switch (led->mode) {
+	case MODE_OFF:		route = 1; break;
+	case MODE_ON:		route = 0; break;
+	case MODE_FOLLOW_ROUTE:	if (route >= 0) route ^= 1; break;
+	case MODE_FOLLOW_MUTE:	/* noop */ break;
+	}
 	if (route >= 0)
-		ledtrig_audio_set(led_trigger_type, route ? LED_OFF : LED_ON);
+		ledtrig_audio_set(led->trigger_type, route ? LED_OFF : LED_ON);
 }
 
 static void snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff)
 {
 	struct snd_kcontrol_volatile *vd;
-	struct list_head *controls;
-	struct snd_ctl_led *lctl;
+	struct snd_ctl_led *led;
+	struct snd_ctl_led_ctl *lctl;
 
 	vd = &kctl->vd[ioff];
-	controls = snd_ctl_led_controls_by_access(vd->access);
-	if (!controls)
+	led = snd_ctl_led_get_by_access(vd->access);
+	if (!led)
 		return;
 	mutex_lock(&snd_ctl_led_mutex);
-	list_for_each_entry(lctl, controls, list)
+	list_for_each_entry(lctl, &led->controls, list)
 		if (lctl->kctl == kctl && lctl->index_offset == ioff) {
 			list_del(&lctl->list);
 			kfree(lctl);
@@ -182,13 +209,13 @@ static void snd_ctl_led_refresh(void)
 static void snd_ctl_led_clean(struct snd_card *card)
 {
 	unsigned int group;
-	struct list_head *controls;
-	struct snd_ctl_led *lctl;
+	struct snd_ctl_led *led;
+	struct snd_ctl_led_ctl *lctl;
 
 	for (group = 0; group < MAX_LED; group++) {
-		controls = &snd_ctl_led_controls[group];
+		led = &snd_ctl_leds[group];
 repeat:
-		list_for_each_entry(lctl, controls, list)
+		list_for_each_entry(lctl, &led->controls, list)
 			if (!card || lctl->card == card) {
 				list_del(&lctl->list);
 				kfree(lctl);
@@ -225,6 +252,82 @@ static void snd_ctl_led_disconnect(struct snd_card *card)
 	snd_ctl_led_refresh();
 }
 
+/*
+ * sysfs
+ */
+
+static ssize_t show_mode(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+	const char *str;
+
+	switch (led->mode) {
+	case MODE_FOLLOW_MUTE:	str = "follow-mute"; break;
+	case MODE_FOLLOW_ROUTE:	str = "follow-route"; break;
+	case MODE_ON:		str = "on"; break;
+	case MODE_OFF:		str = "off"; break;
+	}
+	return sprintf(buf, "%s\n", str);
+}
+
+static ssize_t store_mode(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+	char _buf[16];
+	size_t l = min(count, sizeof(_buf) - 1) + 1;
+	enum snd_ctl_led_mode mode;
+
+	memcpy(_buf, buf, l);
+	_buf[l] = '\0';
+	if (strstr(_buf, "mute"))
+		mode = MODE_FOLLOW_MUTE;
+	else if (strstr(_buf, "route"))
+		mode = MODE_FOLLOW_ROUTE;
+	else if (strncmp(_buf, "off", 3) == 0 || strncmp(_buf, "0", 1) == 0)
+		mode = MODE_OFF;
+	else if (strncmp(_buf, "on", 2) == 0 || strncmp(_buf, "1", 1) == 0)
+		mode = MODE_ON;
+	else
+		return count;
+
+	mutex_lock(&snd_ctl_led_mutex);
+	led->mode = mode;
+	mutex_unlock(&snd_ctl_led_mutex);
+
+	snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
+	return count;
+}
+
+static ssize_t show_brightness(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+
+	return sprintf(buf, "%u\n", ledtrig_audio_get(led->trigger_type));
+}
+
+static DEVICE_ATTR(mode, 0644, show_mode, store_mode);
+static DEVICE_ATTR(brightness, 0444, show_brightness, NULL);
+
+static struct attribute *snd_ctl_led_dev_attrs[] = {
+	&dev_attr_mode.attr,
+	&dev_attr_brightness.attr,
+	NULL,
+};
+
+static const struct attribute_group snd_ctl_led_dev_attr_group = {
+	.attrs = snd_ctl_led_dev_attrs,
+};
+
+static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = {
+	&snd_ctl_led_dev_attr_group,
+	NULL,
+};
+
+static struct device snd_ctl_led_dev;
+
 /*
  * Control layer registration
  */
@@ -237,16 +340,36 @@ static struct snd_ctl_layer_ops snd_ctl_led_lops = {
 
 static int __init snd_ctl_led_init(void)
 {
+	struct snd_ctl_led *led;
 	unsigned int group;
 
-	for (group = 0; group < MAX_LED; group++)
-		INIT_LIST_HEAD(&snd_ctl_led_controls[group]);
+	device_initialize(&snd_ctl_led_dev);
+	snd_ctl_led_dev.class = sound_class;
+	dev_set_name(&snd_ctl_led_dev, "ctl-led");
+	if (device_add(&snd_ctl_led_dev)) {
+		put_device(&snd_ctl_led_dev);
+		return -ENOMEM;
+	}
+	for (group = 0; group < MAX_LED; group++) {
+		led = &snd_ctl_leds[group];
+		INIT_LIST_HEAD(&led->controls);
+		device_initialize(&led->dev);
+		led->dev.parent = &snd_ctl_led_dev;
+		led->dev.groups = snd_ctl_led_dev_attr_groups;
+		dev_set_name(&led->dev, led->name);
+		if (device_add(&led->dev)) {
+			put_device(&led->dev);
+			device_del(&snd_ctl_led_dev);
+			return -ENOMEM;
+		}
+	}
 	snd_ctl_register_layer(&snd_ctl_led_lops);
 	return 0;
 }
 
 static void __exit snd_ctl_led_exit(void)
 {
+	device_del(&snd_ctl_led_dev);
 	snd_ctl_disconnect_layer(&snd_ctl_led_lops);
 	snd_ctl_led_clean(NULL);
 }
-- 
2.29.2

Re: [PATCH v2 0/5] ALSA: control - add generic LED API

[Hans de Goede]

Hi,

On 2/15/21 6:24 PM, Jaroslav Kysela wrote:
> This patchset tries to resolve the diversity in the audio LED
> control among the ALSA drivers. A new control layer registration
> is introduced which allows to run additional operations on
> top of the elementary ALSA sound controls.
> 
> A new control access group (three bits in the access flags)
> was introduced to carry the LED group information for
> the sound controls. The low-level sound drivers can just
> mark those controls using this access group. This information
> is exported to the user space and eventually the user space
> can create sound controls which can belong to a LED group.
> 
> The actual state ('route') evaluation is really easy
> (the minimal value check for all channels / controls / cards).
> If there's more complicated logic for a given hardware,
> the card driver may eventually export a new read-only
> sound control for the LED group and do the logic itself.
> 
> The new LED trigger control code is completely separated
> and possibly optional (there's no symbol dependency).
> The full code separation allows eventually to move this
> LED trigger control to the user space in future.
> Actually it replaces the already present functionality
> in the kernel space (HDA drivers) and allows a quick adoption
> for the recent hardware (SoundWire / ASoC codecs).
> 
> # lsmod | grep snd_ctl_led
> snd_ctl_led            16384  0
> 
> The sound driver implementation is really easy:
> 
> 1) call snd_ctl_led_request() when control LED layer should be
>    automatically activated
>    / it calls module_request("snd-ctl-led") on demand /
> 2) mark all related kcontrols with
> 	SNDRV_CTL_ELEM_ACCESS_SPK_LED or
> 	SNDRV_CTL_ELEM_ACCESS_MIC_LED
> 
> v2 changes:
>   - fix the locking - remove the controls_rwsem read lock
>     in the element get (the consistency is already protected
>     with the global snd_ctl_led_mutex and possible partial
>     value writes are catched with the next value change
>     notification callback)

I'm afraid that lockdep still is unhappy. With v2 there is a new
(different) lockdep warning.

In case you don't know, lockdep disables itself after catching
the first problem, to avoid spamming the logs too much.
So the previous issue was masking this one (or it could be new):

[   22.213898] ======================================================
[   22.213903] WARNING: possible circular locking dependency detected
[   22.213909] 5.11.0+ #255 Tainted: G            E
[   22.213914] ------------------------------------------------------
[   22.213918] systemd-udevd/390 is trying to acquire lock:
[   22.213923] ffff8a7f03d5a720 (&card->controls_rwsem){++++}-{3:3}, at: 0xffffffffc0861896
[   22.213948] 
               but task is already holding lock:
[   22.213952] ffffffffc07772b0 (snd_ctl_layer_rwsem){++++}-{3:3}, at: snd_ctl_register_layer+0x16b/0x360 [snd]
[   22.213977] 
               which lock already depends on the new lock.

[   22.213981] 
               the existing dependency chain (in reverse order) is:
[   22.213985] 
               -> #1 (snd_ctl_layer_rwsem){++++}-{3:3}:
[   22.213998]        down_read+0x40/0x50
[   22.214009]        snd_ctl_notify_one+0x8d/0x150 [snd]
[   22.214022]        snd_ctl_find_id+0x24e/0x350 [snd]
[   22.214034]        snd_ctl_find_id+0x2f3/0x350 [snd]
[   22.214047]        init_module+0x5bbab/0x5da91 [snd_hdmi_lpe_audio]
[   22.214057]        platform_probe+0x3f/0x90
[   22.214065]        really_probe+0xf2/0x440
[   22.214073]        driver_probe_device+0xe1/0x150
[   22.214080]        device_driver_attach+0xa8/0xb0
[   22.214087]        __driver_attach+0x8c/0x150
[   22.214095]        bus_for_each_dev+0x78/0xa0
[   22.214102]        bus_add_driver+0x12e/0x1f0
[   22.214109]        driver_register+0x8f/0xe0
[   22.214116]        do_one_initcall+0x6e/0x2e0
[   22.214125]        do_init_module+0x5c/0x260
[   22.214135]        load_module+0x2570/0x27e0
[   22.214143]        __do_sys_init_module+0x130/0x190
[   22.214151]        do_syscall_64+0x33/0x40
[   22.214158]        entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   22.214166]
               -> #0 (&card->controls_rwsem){++++}-{3:3}:
[   22.214179]        __lock_acquire+0x113d/0x1e10
[   22.214187]        lock_acquire+0xe4/0x390
[   22.214194]        down_read+0x40/0x50
[   22.214200]        0xffffffffc0861896
[   22.214207]        snd_ctl_register_layer+0x183/0x360 [snd]
[   22.214220]        snd_device_register_all+0x4c/0x60 [snd]
[   22.214232]        snd_card_register+0x74/0x1d0 [snd]
[   22.214244]        init_module+0x5bccb/0x5da91 [snd_hdmi_lpe_audio]
[   22.214253]        platform_probe+0x3f/0x90
[   22.214259]        really_probe+0xf2/0x440
[   22.214266]        driver_probe_device+0xe1/0x150
[   22.214273]        device_driver_attach+0xa8/0xb0
[   22.214281]        __driver_attach+0x8c/0x150
[   22.214288]        bus_for_each_dev+0x78/0xa0
[   22.214295]        bus_add_driver+0x12e/0x1f0
[   22.214302]        driver_register+0x8f/0xe0
[   22.214309]        do_one_initcall+0x6e/0x2e0
[   22.214316]        do_init_module+0x5c/0x260
[   22.214324]        load_module+0x2570/0x27e0
[   22.214332]        __do_sys_init_module+0x130/0x190
[   22.214339]        do_syscall_64+0x33/0x40
[   22.214346]        entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   22.214354] 
               other info that might help us debug this:

[   22.214357]  Possible unsafe locking scenario:

[   22.214361]        CPU0                    CPU1
[   22.214365]        ----                    ----
[   22.214368]   lock(snd_ctl_layer_rwsem);
[   22.214376]                                lock(&card->controls_rwsem);
[   22.214383]                                lock(snd_ctl_layer_rwsem);
[   22.214390]   lock(&card->controls_rwsem);
[   22.214397] 
                *** DEADLOCK ***
[   22.214401] 2 locks held by systemd-udevd/390:
[   22.214406]  #0: ffff8a7f0768f188 (&dev->mutex){....}-{3:3}, at: device_driver_attach+0x3b/0xb0
[   22.214426]  #1: ffffffffc07772b0 (snd_ctl_layer_rwsem){++++}-{3:3}, at: snd_ctl_register_layer+0x16b/0x360 [snd]
[   22.214450] 
               stack backtrace:
[   22.214455] CPU: 0 PID: 390 Comm: systemd-udevd Tainted: G            E     5.11.0+ #255
[   22.214463] Hardware name: HP HP x2 Detachable 10-p0XX/827C, BIOS F.11 09/30/2016
[   22.214468] Call Trace:
[   22.214477]  dump_stack+0x8b/0xb0
[   22.214491]  check_noncircular+0xfb/0x110
[   22.214505]  __lock_acquire+0x113d/0x1e10
[   22.214518]  lock_acquire+0xe4/0x390
[   22.214527]  ? 0xffffffffc0861896
[   22.214539]  down_read+0x40/0x50
[   22.214547]  ? 0xffffffffc0861896
[   22.214554]  0xffffffffc0861896
[   22.214562]  snd_ctl_register_layer+0x183/0x360 [snd]
[   22.214578]  snd_device_register_all+0x4c/0x60 [snd]
[   22.214593]  snd_card_register+0x74/0x1d0 [snd]
[   22.214608]  init_module+0x5bccb/0x5da91 [snd_hdmi_lpe_audio]
[   22.214624]  platform_probe+0x3f/0x90
[   22.214633]  really_probe+0xf2/0x440
[   22.214643]  driver_probe_device+0xe1/0x150
[   22.214652]  device_driver_attach+0xa8/0xb0
[   22.214662]  __driver_attach+0x8c/0x150
[   22.214670]  ? device_driver_attach+0xb0/0xb0
[   22.214678]  ? device_driver_attach+0xb0/0xb0
[   22.214687]  bus_for_each_dev+0x78/0xa0
[   22.214696]  bus_add_driver+0x12e/0x1f0
[   22.214706]  driver_register+0x8f/0xe0
[   22.214715]  ? 0xffffffffc06f5000
[   22.214721]  do_one_initcall+0x6e/0x2e0
[   22.214735]  do_init_module+0x5c/0x260
[   22.214745]  load_module+0x2570/0x27e0
[   22.214768]  ? __do_sys_init_module+0x130/0x190
[   22.214776]  __do_sys_init_module+0x130/0x190
[   22.214791]  do_syscall_64+0x33/0x40
[   22.214799]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   22.214809] RIP: 0033:0x7fbdcf3cc6be
[   22.214817] Code: 48 8b 0d bd 27 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8a 27
[   22.214825] RSP: 002b:00007ffea888abe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
[   22.214835] RAX: ffffffffffffffda RBX: 000055bdd044d9f0 RCX: 00007fbdcf3cc6be
[   22.214841] RDX: 00007fbdcf50235a RSI: 000000000000b1f8 RDI: 000055bdd0c549a0
[   22.214846] RBP: 000055bdd0c549a0 R08: 000055bdd0c549a0 R09: 00007ffea8887c88
[   22.214852] R10: 000055bdd0143010 R11: 0000000000000246 R12: 00007fbdcf50235a
[   22.214857] R13: 000055bdd042af40 R14: 0000000000000007 R15: 000055bdd0430bf0

I did not get around to testing your fixup-diff before you send
out v2 last time.

If you can send me another fixup-diff then I'll make sure to
test this before you do a v3, so that we can be sure that
all cases which my setup catches are resolved before sending
out v3.

Regards,

Hans

Re: [PATCH v2 0/5] ALSA: control - add generic LED API

[Jaroslav Kysela]

Dne 21. 02. 21 v 14:14 Hans de Goede napsal(a):

>> v2 changes:
>>   - fix the locking - remove the controls_rwsem read lock
>>     in the element get (the consistency is already protected
>>     with the global snd_ctl_led_mutex and possible partial
>>     value writes are catched with the next value change
>>     notification callback)
> 
> I'm afraid that lockdep still is unhappy. With v2 there is a new
> (different) lockdep warning.

> If you can send me another fixup-diff then I'll make sure to
> test this before you do a v3, so that we can be sure that
> all cases which my setup catches are resolved before sending
> out v3.

Thank you for your test. This change (on top of v2) should resolve this
remaining lockdep:

diff --git a/sound/core/control.c b/sound/core/control.c
index c9f062fada0a..494f0154e8be 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -2051,7 +2051,9 @@ void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
 	for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
 		card = snd_card_ref(card_number);
 		if (card) {
+			down_read(&card->controls_rwsem);
 			lops->lregister(card);
+			up_read(&card->controls_rwsem);
 			snd_card_unref(card);
 		}
 	}
@@ -2113,10 +2115,12 @@ static int snd_ctl_dev_register(struct snd_device *device)
 				  &snd_ctl_f_ops, card, &card->ctl_dev);
 	if (err < 0)
 		return err;
+	down_read(&card->controls_rwsem);
 	down_read(&snd_ctl_layer_rwsem);
 	for (lops = snd_ctl_layer; lops; lops = lops->next)
 		lops->lregister(card);
 	up_read(&snd_ctl_layer_rwsem);
+	up_read(&card->controls_rwsem);
 	return 0;
 }

@@ -2137,10 +2141,12 @@ static int snd_ctl_dev_disconnect(struct snd_device
*device)
 	}
 	read_unlock_irqrestore(&card->ctl_files_rwlock, flags);

+	down_read(&card->controls_rwsem);
 	down_read(&snd_ctl_layer_rwsem);
 	for (lops = snd_ctl_layer; lops; lops = lops->next)
 		lops->ldisconnect(card);
 	up_read(&snd_ctl_layer_rwsem);
+	up_read(&card->controls_rwsem);

 	return snd_unregister_device(&card->ctl_dev);
 }
diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index cafe4c82ca35..b8bb8fd46686 100644
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -235,11 +235,10 @@ static void snd_ctl_led_register(struct snd_card *card)
 	mutex_lock(&snd_ctl_led_mutex);
 	snd_ctl_led_card_valid[card->number] = true;
 	mutex_unlock(&snd_ctl_led_mutex);
-	down_read(&card->controls_rwsem);
+	/* the register callback is already called with held card->controls_rwsem */
 	list_for_each_entry(kctl, &card->controls, list)
 		for (ioff = 0; ioff < kctl->count; ioff++)
 			snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
-	up_read(&card->controls_rwsem);
 	snd_ctl_led_refresh();
 }


					Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.

Re: [PATCH v2 0/5] ALSA: control - add generic LED API

[Hans de Goede]

Hi,

On 2/21/21 7:01 PM, Jaroslav Kysela wrote:
> Dne 21. 02. 21 v 14:14 Hans de Goede napsal(a):
> 
>>> v2 changes:
>>>   - fix the locking - remove the controls_rwsem read lock
>>>     in the element get (the consistency is already protected
>>>     with the global snd_ctl_led_mutex and possible partial
>>>     value writes are catched with the next value change
>>>     notification callback)
>>
>> I'm afraid that lockdep still is unhappy. With v2 there is a new
>> (different) lockdep warning.
> 
>> If you can send me another fixup-diff then I'll make sure to
>> test this before you do a v3, so that we can be sure that
>> all cases which my setup catches are resolved before sending
>> out v3.
> 
> Thank you for your test. This change (on top of v2) should resolve this
> remaining lockdep:

I can confirm that I'm not seeing any more lockdeps warning after
applying this on top of v2 of the series.

Regards,

Hans



> diff --git a/sound/core/control.c b/sound/core/control.c
> index c9f062fada0a..494f0154e8be 100644
> --- a/sound/core/control.c
> +++ b/sound/core/control.c
> @@ -2051,7 +2051,9 @@ void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
>  	for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
>  		card = snd_card_ref(card_number);
>  		if (card) {
> +			down_read(&card->controls_rwsem);
>  			lops->lregister(card);
> +			up_read(&card->controls_rwsem);
>  			snd_card_unref(card);
>  		}
>  	}
> @@ -2113,10 +2115,12 @@ static int snd_ctl_dev_register(struct snd_device *device)
>  				  &snd_ctl_f_ops, card, &card->ctl_dev);
>  	if (err < 0)
>  		return err;
> +	down_read(&card->controls_rwsem);
>  	down_read(&snd_ctl_layer_rwsem);
>  	for (lops = snd_ctl_layer; lops; lops = lops->next)
>  		lops->lregister(card);
>  	up_read(&snd_ctl_layer_rwsem);
> +	up_read(&card->controls_rwsem);
>  	return 0;
>  }
> 
> @@ -2137,10 +2141,12 @@ static int snd_ctl_dev_disconnect(struct snd_device
> *device)
>  	}
>  	read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
> 
> +	down_read(&card->controls_rwsem);
>  	down_read(&snd_ctl_layer_rwsem);
>  	for (lops = snd_ctl_layer; lops; lops = lops->next)
>  		lops->ldisconnect(card);
>  	up_read(&snd_ctl_layer_rwsem);
> +	up_read(&card->controls_rwsem);
> 
>  	return snd_unregister_device(&card->ctl_dev);
>  }
> diff --git a/sound/core/control_led.c b/sound/core/control_led.c
> index cafe4c82ca35..b8bb8fd46686 100644
> --- a/sound/core/control_led.c
> +++ b/sound/core/control_led.c
> @@ -235,11 +235,10 @@ static void snd_ctl_led_register(struct snd_card *card)
>  	mutex_lock(&snd_ctl_led_mutex);
>  	snd_ctl_led_card_valid[card->number] = true;
>  	mutex_unlock(&snd_ctl_led_mutex);
> -	down_read(&card->controls_rwsem);
> +	/* the register callback is already called with held card->controls_rwsem */
>  	list_for_each_entry(kctl, &card->controls, list)
>  		for (ioff = 0; ioff < kctl->count; ioff++)
>  			snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
> -	up_read(&card->controls_rwsem);
>  	snd_ctl_led_refresh();
>  }
> 
> 
> 					Jaroslav
>