Merge tag 'mfd-for-linus-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd

[pandora-kernel.git] / Documentation / dmaengine / provider.txt

diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt
index 766658c..05d2280 100644 (file)
--- a/Documentation/dmaengine/provider.txt
+++ b/Documentation/dmaengine/provider.txt
@@ -113,6 +113,31 @@ need to initialize a few fields in there:
   * channels:  should be initialized as a list using the
                INIT_LIST_HEAD macro for example
 
   * channels:  should be initialized as a list using the
                INIT_LIST_HEAD macro for example
 

+  * src_addr_widths:
+    - should contain a bitmask of the supported source transfer width
+
+  * dst_addr_widths:
+    - should contain a bitmask of the supported destination transfer
+      width
+
+  * directions:
+    - should contain a bitmask of the supported slave directions
+      (i.e. excluding mem2mem transfers)
+
+  * residue_granularity:
+    - Granularity of the transfer residue reported to dma_set_residue.
+    - This can be either:
+      + Descriptor
+        -> Your device doesn't support any kind of residue
+           reporting. The framework will only know that a particular
+           transaction descriptor is done.
+      + Segment
+        -> Your device is able to report which chunks have been
+           transferred
+      + Burst
+        -> Your device is able to report which burst have been
+           transferred
+

   * dev:       should hold the pointer to the struct device associated
                to your current driver instance.
 
   * dev:       should hold the pointer to the struct device associated
                to your current driver instance.
 


@@ -274,48 +299,36 @@ supported.
        account the current period.
      - This function can be called in an interrupt context.
 
        account the current period.
      - This function can be called in an interrupt context.
 

-   * 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

 
 Misc notes (stuff that should be documented, but don't really know
 where to put them)
 
 Misc notes (stuff that should be documented, but don't really know
 where to put them)