According to the DW DMA controller Databook 2.18b (page 40 "3.5 Memory
Peripherals") memory peripherals don't have handshaking interface
connected to the controller, therefore they can never be a flow
controller. Since the CTLx.SRC_MSIZE and CTLx.DEST_MSIZE are properties
valid only for peripherals with a handshaking interface, we can freely
zero these fields out if the memory peripheral is selected to be the
source or the destination of the DMA transfers.
Note according to the databook, length of burst transfers to memory is
always equal to the number of data items available in a channel FIFO or
data items required to complete the block transfer, whichever is smaller;
length of burst transfers from memory is always equal to the space
available in a channel FIFO or number of data items required to complete
the block transfer, whichever is smaller.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200731200826.9292-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Intel iDMA 32-bit doesn't have a concept of bus masters and thus
there is no need to setup any kind of masters in the CTL_LO register.
Moreover, the burst size for memory-to-memory transfer is not what is says,
we need to have a corrected list of possible sizes. Note, that
the size of 8 items, each of that up to 4 bytes, is chosen because of
maximum of 1/2 FIFO, which is 64 bytes on Intel Merrifield.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
For Intel iDMA 32-bit the channel can be drained on a suspend.
We need to reset the bit on the resume to return a status quo.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Here is a kinda big refactoring that should have been done
in the first place, when Intel iDMA 32-bit support appeared.
It splits operations which are different to Synopsys DesignWare and
Intel iDMA 32-bit controllers.
No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
