• Takashi Sakamoto's avatar
    ALSA: fireworks: Add command/response functionality into hwdep interface · 555e8a8f
    Takashi Sakamoto authored
    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: 's avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
    Signed-off-by: 's avatarTakashi Iwai <tiwai@suse.de>
    555e8a8f
fireworks_command.c 9.77 KB