ALSA: fireworks: Add command/response functionality into hwdep interface

This commit adds two functionality for hwdep interface, adds two parameters for
this driver, add a node for proc interface.

To receive responses from devices, this driver already allocate own callback
into initial memory space in host controller. This means no one can allocate
its own callback to the address. So this driver must give a way for user
applications to receive responses.

This commit adds a functionality to receive responses via hwdep interface. The
application can receive responses to read from this interface. To achieve this,
this commit adds a buffer to queue responses. The default size of this buffer is
1024 bytes. This size can be changed to give preferrable size to
'resp_buf_size' parameter for this driver. The application should notice rest
of space in this buffer because this driver don't push responses when this
buffer has no space.

Additionaly, this commit adds a functionality to transmit commands via hwdep
interface. The application can transmit commands to write into this interface.
I note that the application can transmit one command at once, but can receive
as many responses as possible untill the user-buffer is full.

When using these interfaces, the application must keep maximum number of
sequence number in command within the number in firewire.h because this driver
uses this number to distinguish the response is against the command by the
application or this driver.

Usually responses against commands which the application transmits are pushed
into this buffer. But to enable 'resp_buf_debug' parameter for this driver, all
responses are pushed into the buffer. When using this mode, I reccomend to
expand the size of buffer.

Finally this commit adds a new node into proc interface to output status of the
buffer.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/uapi/sound/firewire.h b/include/uapi/sound/firewire.h
index fc9afb261989..bfc0e23e47a2 100644
--- a/include/uapi/sound/firewire.h
+++ b/include/uapi/sound/firewire.h
@@ -2,11 +2,13 @@
 #define _UAPI_SOUND_FIREWIRE_H_INCLUDED
 
 #include <linux/ioctl.h>
+#include <linux/types.h>
 
 /* events can be read() from the hwdep device */
 
 #define SNDRV_FIREWIRE_EVENT_LOCK_STATUS	0x000010cc
 #define SNDRV_FIREWIRE_EVENT_DICE_NOTIFICATION	0xd1ce004e
+#define SNDRV_FIREWIRE_EVENT_EFW_RESPONSE	0x4e617475
 
 struct snd_firewire_event_common {
 	unsigned int type; /* SNDRV_FIREWIRE_EVENT_xxx */
@@ -22,10 +24,27 @@ struct snd_firewire_event_dice_notification {
 	unsigned int notification; /* DICE-specific bits */
 };
 
+#define SND_EFW_TRANSACTION_USER_SEQNUM_MAX	((__u32)((__u16)~0) - 1)
+/* each field should be in big endian */
+struct snd_efw_transaction {
+	__be32 length;
+	__be32 version;
+	__be32 seqnum;
+	__be32 category;
+	__be32 command;
+	__be32 status;
+	__be32 params[0];
+};
+struct snd_firewire_event_efw_response {
+	unsigned int type;
+	__be32 response[0];	/* some responses */
+};
+
 union snd_firewire_event {
 	struct snd_firewire_event_common            common;
 	struct snd_firewire_event_lock_status       lock_status;
 	struct snd_firewire_event_dice_notification dice_notification;
+	struct snd_firewire_event_efw_response      efw_response;
 };