- * device_control
- - Used by client drivers to control and configure the channel it
- has a handle on.
- - Called with a command and an argument
- + The command is one of the values listed by the enum
- dma_ctrl_cmd. The valid commands are:
- + DMA_PAUSE
- + Pauses a transfer on the channel
- + This command should operate synchronously on the channel,
- pausing right away the work of the given channel
- + DMA_RESUME
- + Restarts a transfer on the channel
- + This command should operate synchronously on the channel,
- resuming right away the work of the given channel
- + DMA_TERMINATE_ALL
- + Aborts all the pending and ongoing transfers on the
- channel
- + This command should operate synchronously on the channel,
- terminating right away all the channels
- + DMA_SLAVE_CONFIG
- + Reconfigures the channel with passed configuration
- + This command should NOT perform synchronously, or on any
- currently queued transfers, but only on subsequent ones
- + In this case, the function will receive a
- dma_slave_config structure pointer as an argument, that
- will detail which configuration to use.
- + Even though that structure contains a direction field,
- this field is deprecated in favor of the direction
- argument given to the prep_* functions
- + FSLDMA_EXTERNAL_START
- + TODO: Why does that even exist?
- + The argument is an opaque unsigned long. This actually is a
- pointer to a struct dma_slave_config that should be used only
- in the DMA_SLAVE_CONFIG.
-
- * device_slave_caps
- - Called through the framework by client drivers in order to have
- an idea of what are the properties of the channel allocated to
- them.
- - Such properties are the buswidth, available directions, etc.
- - Required for every generic layer doing DMA transfers, such as
- ASoC.
+ * device_config
+ - Reconfigures the channel with the configuration given as
+ argument
+ - This command should NOT perform synchronously, or on any
+ currently queued transfers, but only on subsequent ones
+ - In this case, the function will receive a dma_slave_config
+ structure pointer as an argument, that will detail which
+ configuration to use.
+ - Even though that structure contains a direction field, this
+ field is deprecated in favor of the direction argument given to
+ the prep_* functions
+ - This call is mandatory for slave operations only. This should NOT be
+ set or expected to be set for memcpy operations.
+ If a driver support both, it should use this call for slave
+ operations only and not for memcpy ones.
+
+ * device_pause
+ - Pauses a transfer on the channel
+ - This command should operate synchronously on the channel,
+ pausing right away the work of the given channel
+
+ * device_resume
+ - Resumes a transfer on the channel
+ - This command should operate synchronously on the channel,
+ pausing right away the work of the given channel
+
+ * device_terminate_all
+ - Aborts all the pending and ongoing transfers on the channel
+ - This command should operate synchronously on the channel,
+ terminating right away all the channels