Merge tag 'dmaengine-4.21-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:
 "This includes a new driver, removes R-Mobile APE6 as it is no longer
  used, sprd cyclic dma support, last batch of dma_slave_config
  direction removal and random updates to bunch of drivers.

  Summary:
   - New driver for UniPhier MIO DMA controller
   - Remove R-Mobile APE6 support
   - Sprd driver updates and support for cyclic link-list
   - Remove dma_slave_config direction usage from rest of drivers
   - Minor updates to dmatest, dw-dmac, zynqmp and bcm dma drivers"

* tag 'dmaengine-4.21-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (48 commits)
  dmaengine: qcom_hidma: convert to DEFINE_SHOW_ATTRIBUTE
  dmaengine: pxa: remove DBGFS_FUNC_DECL()
  dmaengine: mic_x100_dma: convert to DEFINE_SHOW_ATTRIBUTE
  dmaengine: amba-pl08x: convert to DEFINE_SHOW_ATTRIBUTE
  dmaengine: Documentation: Add documentation for multi chan testing
  dmaengine: dmatest: Add transfer_size parameter
  dmaengine: dmatest: Add alignment parameter
  dmaengine: dmatest: Use fixed point div to calculate iops
  dmaengine: dmatest: Add support for multi channel testing
  dmaengine: rcar-dmac: Document R8A774C0 bindings
  dt-bindings: dmaengine: usb-dmac: Add binding for r8a774c0
  dmaengine: zynqmp_dma: replace spin_lock_bh with spin_lock_irqsave
  dmaengine: sprd: Add me as one of the module authors
  dmaengine: sprd: Support DMA 2-stage transfer mode
  dmaengine: sprd: Support DMA link-list cyclic callback
  dmaengine: sprd: Set cur_desc as NULL when free or terminate one dma channel
  dmaengine: sprd: Fix the last link-list configuration
  dmaengine: sprd: Get transfer residue depending on the transfer direction
  dmaengine: sprd: Remove direction usage from struct dma_slave_config
  dmaengine: dmatest: fix a small memory leak in dmatest_func()
  ...

1 files changed, 103 insertions, 6 deletions

diff --git a/Documentation/driver-api/dmaengine/dmatest.rst b/Documentation/driver-api/dmaengine/dmatest.rst
index 49efebd2c043..8d81f1a7169b 100644
--- a/Documentation/driver-api/dmaengine/dmatest.rst
+++ b/Documentation/driver-api/dmaengine/dmatest.rst
@@ -30,28 +30,43 @@ Part 2 - When dmatest is built as a module
 
 Example of usage::
 
-    % modprobe dmatest channel=dma0chan0 timeout=2000 iterations=1 run=1
+    % modprobe dmatest timeout=2000 iterations=1 channel=dma0chan0 run=1
 
 ...or::
 
     % modprobe dmatest
-    % echo dma0chan0 > /sys/module/dmatest/parameters/channel
     % echo 2000 > /sys/module/dmatest/parameters/timeout
     % echo 1 > /sys/module/dmatest/parameters/iterations
+    % echo dma0chan0 > /sys/module/dmatest/parameters/channel
     % echo 1 > /sys/module/dmatest/parameters/run
 
 ...or on the kernel command line::
 
-    dmatest.channel=dma0chan0 dmatest.timeout=2000 dmatest.iterations=1 dmatest.run=1
+    dmatest.timeout=2000 dmatest.iterations=1 dmatest.channel=dma0chan0 dmatest.run=1
+
+Example of multi-channel test usage:
+    % modprobe dmatest
+    % echo 2000 > /sys/module/dmatest/parameters/timeout
+    % echo 1 > /sys/module/dmatest/parameters/iterations
+    % echo dma0chan0 > /sys/module/dmatest/parameters/channel
+    % echo dma0chan1 > /sys/module/dmatest/parameters/channel
+    % echo dma0chan2 > /sys/module/dmatest/parameters/channel
+    % echo 1 > /sys/module/dmatest/parameters/run
 
+Note: the channel parameter should always be the last parameter set prior to
+running the test (setting run=1), this is because upon setting the channel
+parameter, that specific channel is requested using the dmaengine and a thread
+is created with the existing parameters. This thread is set as pending
+and will be executed once run is set to 1. Any parameters set after the thread
+is created are not applied.
 .. hint::
   available channel list could be extracted by running the following command::
 
     % ls -1 /sys/class/dma/
 
-Once started a message like "dmatest: Started 1 threads using dma0chan0" is
-emitted. After that only test failure messages are reported until the test
-stops.
+Once started a message like " dmatest: Added 1 threads using dma0chan0" is
+emitted. A thread for that specific channel is created and is now pending, the
+pending thread is started once run is to 1.
 
 Note that running a new test will not stop any in progress test.
 
@@ -116,3 +131,85 @@ Example::
 
 The details of a data miscompare error are also emitted, but do not follow the
 above format.
+
+Part 5 - Handling channel allocation
+====================================
+
+Allocating Channels
+-------------------
+
+Channels are required to be configured prior to starting the test run.
+Attempting to run the test without configuring the channels will fail.
+
+Example::
+
+    % echo 1 > /sys/module/dmatest/parameters/run
+    dmatest: Could not start test, no channels configured
+
+Channels are registered using the "channel" parameter. Channels can be requested by their
+name, once requested, the channel is registered and a pending thread is added to the test list.
+
+Example::
+
+    % echo dma0chan2 > /sys/module/dmatest/parameters/channel
+    dmatest: Added 1 threads using dma0chan2
+
+More channels can be added by repeating the example above.
+Reading back the channel parameter will return the name of last channel that was added successfully.
+
+Example::
+
+    % echo dma0chan1 > /sys/module/dmatest/parameters/channel
+    dmatest: Added 1 threads using dma0chan1
+    % echo dma0chan2 > /sys/module/dmatest/parameters/channel
+    dmatest: Added 1 threads using dma0chan2
+    % cat /sys/module/dmatest/parameters/channel
+    dma0chan2
+
+Another method of requesting channels is to request a channel with an empty string, Doing so
+will request all channels available to be tested:
+
+Example::
+
+    % echo "" > /sys/module/dmatest/parameters/channel
+    dmatest: Added 1 threads using dma0chan0
+    dmatest: Added 1 threads using dma0chan3
+    dmatest: Added 1 threads using dma0chan4
+    dmatest: Added 1 threads using dma0chan5
+    dmatest: Added 1 threads using dma0chan6
+    dmatest: Added 1 threads using dma0chan7
+    dmatest: Added 1 threads using dma0chan8
+
+At any point during the test configuration, reading the "test_list" parameter will
+print the list of currently pending tests.
+
+Example::
+
+    % cat /sys/module/dmatest/parameters/test_list
+    dmatest: 1 threads using dma0chan0
+    dmatest: 1 threads using dma0chan3
+    dmatest: 1 threads using dma0chan4
+    dmatest: 1 threads using dma0chan5
+    dmatest: 1 threads using dma0chan6
+    dmatest: 1 threads using dma0chan7
+    dmatest: 1 threads using dma0chan8
+
+Note: Channels will have to be configured for each test run as channel configurations do not
+carry across to the next test run.
+
+Releasing Channels
+-------------------
+
+Channels can be freed by setting run to 0.
+
+Example::
+    % echo dma0chan1 > /sys/module/dmatest/parameters/channel
+    dmatest: Added 1 threads using dma0chan1
+    % cat /sys/class/dma/dma0chan1/in_use
+    1
+    % echo 0 > /sys/module/dmatest/parameters/run
+    % cat /sys/class/dma/dma0chan1/in_use
+    0
+
+Channels allocated by previous test runs are automatically freed when a new
+channel is requested after completing a successful test run.