[ALSA] dynamic minors (4/6): dynamic minor number allocation

Modules: ALSA Core,ALSA Minor Numbers

Add an option to allocate device file minor numbers dynamically.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 25 insertions, 4 deletions

diff --git a/include/sound/minors.h b/include/sound/minors.h
index a17b5c9961bb..46bcd2023ed8 100644
--- a/include/sound/minors.h
+++ b/include/sound/minors.h
@@ -26,18 +26,20 @@
 #define SNDRV_MINOR_DEVICE(minor)       ((minor) & 0x001f)
 #define SNDRV_MINOR(card, dev)          (((card) << 5) | (dev))
 
-#define SNDRV_MINOR_CONTROL             0       /* 0 - 0 */
+/* these minors can still be used for autoloading devices (/dev/aload*) */
+#define SNDRV_MINOR_CONTROL             0       /* 0 */
 #define SNDRV_MINOR_GLOBAL              1       /* 1 */
 #define SNDRV_MINOR_SEQUENCER           (SNDRV_MINOR_GLOBAL + 0 * 32)
 #define SNDRV_MINOR_TIMER               (SNDRV_MINOR_GLOBAL + 1 * 32)
+
+#ifndef CONFIG_SND_DYNAMIC_MINORS
+                                                /* 2 - 3 (reserved) */
 #define SNDRV_MINOR_HWDEP               4       /* 4 - 7 */
-#define SNDRV_MINOR_HWDEPS              4
 #define SNDRV_MINOR_RAWMIDI             8       /* 8 - 15 */
-#define SNDRV_MINOR_RAWMIDIS            8
 #define SNDRV_MINOR_PCM_PLAYBACK        16      /* 16 - 23 */
 #define SNDRV_MINOR_PCM_CAPTURE         24      /* 24 - 31 */
-#define SNDRV_MINOR_PCMS                8
 
+/* same as first respective minor number to make minor allocation easier */
 #define SNDRV_DEVICE_TYPE_CONTROL       SNDRV_MINOR_CONTROL
 #define SNDRV_DEVICE_TYPE_HWDEP         SNDRV_MINOR_HWDEP
 #define SNDRV_DEVICE_TYPE_RAWMIDI       SNDRV_MINOR_RAWMIDI
@@ -46,6 +48,25 @@
 #define SNDRV_DEVICE_TYPE_SEQUENCER     SNDRV_MINOR_SEQUENCER
 #define SNDRV_DEVICE_TYPE_TIMER         SNDRV_MINOR_TIMER
 
+#else /* CONFIG_SND_DYNAMIC_MINORS */
+
+enum {
+        SNDRV_DEVICE_TYPE_CONTROL,
+        SNDRV_DEVICE_TYPE_SEQUENCER,
+        SNDRV_DEVICE_TYPE_TIMER,
+        SNDRV_DEVICE_TYPE_HWDEP,
+        SNDRV_DEVICE_TYPE_RAWMIDI,
+        SNDRV_DEVICE_TYPE_PCM_PLAYBACK,
+        SNDRV_DEVICE_TYPE_PCM_CAPTURE,
+};
+
+#endif /* CONFIG_SND_DYNAMIC_MINORS */
+
+#define SNDRV_MINOR_HWDEPS              4
+#define SNDRV_MINOR_RAWMIDIS            8
+#define SNDRV_MINOR_PCMS                8
+
+
 #ifdef CONFIG_SND_OSSEMUL
 
 #define SNDRV_MINOR_OSS_DEVICES         16