DCMD_BT_ISOC_ENABLE

Enable Bluetooth connections for audio playback and capture

Synopsis:

#include <ado_pcm/dcmd_bluetooth.h>

#define DCMD_BT_ISOC_ENABLE   _IOW( 'Z', 0x01, struct _bt_isoch )

Arguments to devctl():

Argument Value
filedes A file descriptor that you obtained by opening the device
dcmd DCMD_BT_ISOC_ENABLE
dev_data_ptr A pointer to a bt_isoch_t structure
n_bytes sizeof(bt_isoch_t)
dev_info_ptr NULL

Description:

This command enables Bluetooth connections for audio playback and capture. It tells the audio driver when it's allowed to accept users' connections to the device handle for audio playback/capture. The usage is:

  1. The application codes establishes the Bluetooth connection.
  2. Once the connection is established, issue the DCMD_BT_ISOC_ENABLE command to enable the audio driver interface for client use.
  3. The client application can then successfully call snd_pcm_plugin_params() or snd_pcm_channel_params() against the audio device handle for the CSR BT USB-Audio device.
  4. When the Bluetooth connection is dropped (or about to be disconnected), the application should issue the DCMD_BT_ISOC_DISABLE command to cause the driver to fail any further requests to use the audio driver until the connection is reestablished and the DCMD_BT_ISOC_ENABLE command is sent.
Note:
  • If the audio interface is active when the DCDM_BT_ISOC_DISABLE command is issued, the driver makes the active stream fail with an error of SND_PCM_STATUS_ERROR (i.e., all further read/write calls to the audio interface will fail). The audio stream can't be recovered until the DCMD_BT_ISOC_ENABLE is sent.
  • Any attempt to call snd_pcm_plugin_param() or snd_pcm_channel_params() the audio interface while not in the enabled state fails with an error of EAGAIN, and the why_failed member of the snd_pcm_channel_params_t structure is set to SND_PCM_PARAMS_NO_CHANNEL.

Input:

A filled-in bt_isoch_t structure: 

typedef struct _bt_isoch {
        uint32_t                sco_hdl;
        uint32_t                rsvd[10];
} bt_isoch_t;

Set sco_hdl to the handle of the Bluetooth connection.

Output:

None.

See also:

snd_pcm_channel_params(), snd_pcm_channel_params_t, snd_pcm_plugin_params() in the Audio Developer's Guide

devctl() in the QNX Neutrino C Library Reference

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