ALSA: Add a hook capability to vmaster controls (2ad787e9) · Commits · 戴 / test

include/sound/control.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -227,6 +227,11 @@ snd_ctl_add_slave_uncached(struct snd_kcontrol *master,
		return _snd_ctl_add_slave(master, slave, SND_CTL_SLAVE_NEED_UPDATE);
		}

		int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
		void (hook)(void private_data, int),
		void *private_data);
		void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kctl);

		/*
		* Helper functions for jack-detection controls
		*/

sound/core/vmaster.c

+45 −1

Original line number	Diff line number	Diff line
		@@ -37,6 +37,8 @@ struct link_master {
		struct link_ctl_info info;
		int val; /* the master value */
		unsigned int tlv[4];
		void (hook)(void private_data, int);
		void *hook_private_data;
		};

		/*
		@@ -126,7 +128,9 @@ static int master_init(struct link_master *master)
		master->info.count = 1; /* always mono */
		/* set full volume as default (= no attenuation) */
		master->val = master->info.max_val;
		return 0;
		if (master->hook)
		master->hook(master->hook_private_data, master->val);
		return 1;
		}
		return -ENOENT;
		}
		@@ -329,6 +333,8 @@ static int master_put(struct snd_kcontrol *kcontrol,
		slave_put_val(slave, uval);
		}
		kfree(uval);
		if (master->hook && !err)
		master->hook(master->hook_private_data, master->val);
		return 1;
		}

		@@ -408,3 +414,41 @@ struct snd_kcontrol snd_ctl_make_virtual_master(char name,
		return kctl;
		}
		EXPORT_SYMBOL(snd_ctl_make_virtual_master);

		/**
		* snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
		* @kcontrol: vmaster kctl element
		* @hook: the hook function
		*
		* Adds the given hook to the vmaster control element so that it's called
		* at each time when the value is changed.
		*/
		int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
		void (hook)(void private_data, int),
		void *private_data)
		{
		struct link_master *master = snd_kcontrol_chip(kcontrol);
		master->hook = hook;
		master->hook_private_data = private_data;
		return 0;
		}
		EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);

		/**
		* snd_ctl_sync_vmaster_hook - Sync the vmaster hook
		* @kcontrol: vmaster kctl element
		*
		* Call the hook function to synchronize with the current value of the given
		* vmaster element. NOP when NULL is passed to @kcontrol or the hook doesn't
		* exist.
		*/
		void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kcontrol)
		{
		struct link_master *master;
		if (!kcontrol)
		return;
		master = snd_kcontrol_chip(kcontrol);
		if (master->hook)
		master->hook(master->hook_private_data, master->val);
		}
		EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster_hook);

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