ALSA: mpu401: clean up interrupt specification
The semantics of snd_mpu401_uart_new()'s interrupt parameters are
somewhat counterintuitive: To prevent the function from allocating its
own interrupt, either the irq number must be invalid, or the irq_flags
parameter must be zero. At the same time, the irq parameter being
invalid specifies that the mpu401 code has to work without an interrupt
allocated by the caller. This implies that, if there is an interrupt
and it is allocated by the caller, the irq parameter must be set to
a valid-looking number which then isn't actually used.
With the removal of IRQF_DISABLED, zero becomes a valid irq_flags value,
which forces us to handle the parameters differently.
This patch introduces a new flag MPU401_INFO_IRQ_HOOK for when the
device interrupt is handled by the caller, and makes the allocation of
the interrupt to depend only on the irq parameter. As suggested by
Takashi, the irq_flags parameter was dropped because, when used, it had
the constant value IRQF_DISABLED.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/mpu401.h b/include/sound/mpu401.h
index 1f1d53f..20230db 100644
--- a/include/sound/mpu401.h
+++ b/include/sound/mpu401.h
@@ -50,7 +50,10 @@
#define MPU401_INFO_INTEGRATED (1 << 2) /* integrated h/w port */
#define MPU401_INFO_MMIO (1 << 3) /* MMIO access */
#define MPU401_INFO_TX_IRQ (1 << 4) /* independent TX irq */
+#define MPU401_INFO_IRQ_HOOK (1 << 5) /* mpu401 irq handler is called
+ from driver irq handler */
#define MPU401_INFO_NO_ACK (1 << 6) /* No ACK cmd needed */
+#define MPU401_INFO_USE_TIMER (1 << 15) /* internal */
#define MPU401_MODE_BIT_INPUT 0
#define MPU401_MODE_BIT_OUTPUT 1
@@ -73,8 +76,7 @@
unsigned long port; /* base port of MPU-401 chip */
unsigned long cport; /* port + 1 (usually) */
struct resource *res; /* port resource */
- int irq; /* IRQ number of MPU-401 chip (-1 = poll) */
- int irq_flags;
+ int irq; /* IRQ number of MPU-401 chip */
unsigned long mode; /* MPU401_MODE_XXXX */
int timer_invoked;
@@ -131,7 +133,6 @@
unsigned long port,
unsigned int info_flags,
int irq,
- int irq_flags,
struct snd_rawmidi ** rrawmidi);
#endif /* __SOUND_MPU401_H */