ALSA: seq: Allow the tristate build of OSS emulation

Currently OSS sequencer emulation is tied with ALSA sequencer core,
both are built in the same level; i.e. when CONFIG_SND_SEQUENCER=y,
the OSS sequencer emulation is also always built-in, even though the
functionality can be built as an individual module.

This patch changes the rule and allows users to build snd-seq-oss
module while others are built-in.  Essentially, it's just a few simple
changes in Kconfig and Makefile.  Some driver codes like opl3 need to
convert from the simple ifdef to IS_ENABLED().  But that's all.

You might wonder how about the dependency: right, it can be messy, but
it still works.  Since we rewrote the sequencer binding with the
standard bus, the driver can be bound at any time on demand.  So, the
synthesizer driver module can be loaded individually from the OSS
emulation core before/after it.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/emux_synth.h

@@ -25,9 +25,7 @@
 #include <sound/seq_device.h>
 #include <sound/soundfont.h>
 #include <sound/seq_midi_emul.h>
-#ifdef CONFIG_SND_SEQUENCER_OSS
 #include <sound/seq_oss.h>
-#endif
 #include <sound/emux_legacy.h>
 #include <sound/seq_virmidi.h>
 
@@ -66,7 +64,7 @@ struct snd_emux_operators {
 		       const void __user *data, long count);
 	void (*sysex)(struct snd_emux *emu, char *buf, int len, int parsed,
 		      struct snd_midi_channel_set *chset);
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	int (*oss_ioctl)(struct snd_emux *emu, int cmd, int p1, int p2);
 #endif
 };
@@ -129,7 +127,7 @@ struct snd_emux {
 	struct snd_info_entry *proc;
 #endif
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	struct snd_seq_device *oss_synth;
 #endif
 };
@@ -150,7 +148,7 @@ struct snd_emux_port {
 #ifdef SNDRV_EMUX_USE_RAW_EFFECT
 	struct snd_emux_effect_table *effect;
 #endif
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	struct snd_seq_oss_arg *oss_arg;
 #endif
 };

include/sound/opl3.h

@@ -55,10 +55,8 @@
 #include <sound/hwdep.h>
 #include <sound/timer.h>
 #include <sound/seq_midi_emul.h>
-#ifdef CONFIG_SND_SEQUENCER_OSS
 #include <sound/seq_oss.h>
 #include <sound/seq_oss_legacy.h>
-#endif
 #include <sound/seq_device.h>
 #include <sound/asound_fm.h>
 
@@ -330,7 +328,7 @@ struct snd_opl3 {
 	struct snd_seq_device *seq_dev;	/* sequencer device */
 	struct snd_midi_channel_set * chset;
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	struct snd_seq_device *oss_seq_dev;	/* OSS sequencer device */
 	struct snd_midi_channel_set * oss_chset;
 #endif

sound/core/Kconfig

@@ -110,7 +110,7 @@ config SND_PCM_TIMER
 	  footprint, about 20KB on x86_64 platform.
 
 config SND_SEQUENCER_OSS
-	bool "OSS Sequencer API"
+	tristate "OSS Sequencer API"
 	depends on SND_SEQUENCER
 	depends on SND_OSSEMUL
 	help

sound/core/seq/Makefile

@@ -15,10 +15,9 @@ snd-seq-dummy-objs := seq_dummy.o
 snd-seq-virmidi-objs := seq_virmidi.o
 
 obj-$(CONFIG_SND_SEQUENCER) += snd-seq.o snd-seq-device.o
-ifeq ($(CONFIG_SND_SEQUENCER_OSS),y)
-  obj-$(CONFIG_SND_SEQUENCER) += snd-seq-midi-event.o
-  obj-$(CONFIG_SND_SEQUENCER) += oss/
-endif
+obj-$(CONFIG_SND_SEQUENCER_OSS) += snd-seq-midi-event.o
+obj-$(CONFIG_SND_SEQUENCER_OSS) += oss/
+
 obj-$(CONFIG_SND_SEQ_DUMMY) += snd-seq-dummy.o
 
 # Toplevel Module Dependency

sound/core/seq/oss/Makefile

@@ -7,4 +7,4 @@ snd-seq-oss-objs  := seq_oss.o seq_oss_init.o seq_oss_timer.o seq_oss_ioctl.o \
 		     seq_oss_event.o seq_oss_rw.o seq_oss_synth.o \
 		     seq_oss_midi.o seq_oss_readq.o seq_oss_writeq.o
 
-obj-$(CONFIG_SND_SEQUENCER) += snd-seq-oss.o
+obj-$(CONFIG_SND_SEQUENCER_OSS) += snd-seq-oss.o

sound/drivers/opl3/opl3_seq.c

@@ -252,7 +252,7 @@ static int snd_opl3_seq_probe(struct device *_dev)
 	spin_lock_init(&opl3->sys_timer_lock);
 	opl3->sys_timer_status = 0;
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	snd_opl3_init_seq_oss(opl3, name);
 #endif
 	return 0;
@@ -267,7 +267,7 @@ static int snd_opl3_seq_remove(struct device *_dev)
 	if (opl3 == NULL)
 		return -EINVAL;
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	snd_opl3_free_seq_oss(opl3);
 #endif
 	if (opl3->seq_client >= 0) {

sound/drivers/opl3/opl3_voice.h

@@ -44,9 +44,12 @@ void snd_opl3_load_drums(struct snd_opl3 *opl3);
 void snd_opl3_drum_switch(struct snd_opl3 *opl3, int note, int on_off, int vel, struct snd_midi_channel *chan);
 
 /* Prototypes for opl3_oss.c */
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 void snd_opl3_init_seq_oss(struct snd_opl3 *opl3, char *name);
 void snd_opl3_free_seq_oss(struct snd_opl3 *opl3);
+#else
+#define snd_opl3_init_seq_oss(opl3, name) /* NOP */
+#define snd_opl3_free_seq_oss(opl3) /* NOP */
 #endif
 
 #endif

sound/isa/sb/emu8000_callback.c

@@ -36,7 +36,7 @@ static void reset_voice(struct snd_emux *emu, int ch);
 static void terminate_voice(struct snd_emux_voice *vp);
 static void sysex(struct snd_emux *emu, char *buf, int len, int parsed,
 		  struct snd_midi_channel_set *chset);
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 static int oss_ioctl(struct snd_emux *emu, int cmd, int p1, int p2);
 #endif
 static int load_fx(struct snd_emux *emu, int type, int mode,
@@ -76,7 +76,7 @@ static struct snd_emux_operators emu8000_ops = {
 	.sample_reset = snd_emu8000_sample_reset,
 	.load_fx =	load_fx,
 	.sysex =	sysex,
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	.oss_ioctl =	oss_ioctl,
 #endif
 };
@@ -477,7 +477,7 @@ sysex(struct snd_emux *emu, char *buf, int len, int parsed, struct snd_midi_chan
 }
 
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 /*
  * OSS ioctl callback
  */

sound/synth/emux/emux.c

@@ -47,7 +47,7 @@ int snd_emux_new(struct snd_emux **remu)
 	mutex_init(&emu->register_mutex);
 
 	emu->client = -1;
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	emu->oss_synth = NULL;
 #endif
 	emu->max_voices = 0;
@@ -123,7 +123,7 @@ int snd_emux_register(struct snd_emux *emu, struct snd_card *card, int index, ch
 	snd_emux_init_voices(emu);
 
 	snd_emux_init_seq(emu, card, index);
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	snd_emux_init_seq_oss(emu);
 #endif
 	snd_emux_init_virmidi(emu, card);
@@ -150,7 +150,7 @@ int snd_emux_free(struct snd_emux *emu)
 
 	snd_emux_proc_free(emu);
 	snd_emux_delete_virmidi(emu);
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 	snd_emux_detach_seq_oss(emu);
 #endif
 	snd_emux_detach_seq(emu);

sound/synth/emux/emux_effect.c

@@ -150,7 +150,7 @@ effect_get_offset(struct snd_midi_channel *chan, int lo, int hi, int mode)
 	return addr;
 }
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
+#if IS_ENABLED(CONFIG_SND_SEQUENCER_OSS)
 /* change effects - for OSS sequencer compatibility */
 void
 snd_emux_send_effect_oss(struct snd_emux_port *port,

sound/synth/emux/emux_oss.c

@@ -23,8 +23,6 @@
  */
 
 
-#ifdef CONFIG_SND_SEQUENCER_OSS
-
 #include <linux/export.h>
 #include <linux/uaccess.h>
 #include <sound/core.h>
@@ -505,5 +503,3 @@ fake_event(struct snd_emux *emu, struct snd_emux_port *port, int ch, int param,
 	ev.data.control.value = val;
 	snd_emux_event_input(&ev, 0, port, atomic, hop);
 }
-
-#endif /* CONFIG_SND_SEQUENCER_OSS */