6192ff7a44
The EBI2 NAND controller directly remaps register read buffer with
dma_map_sg and DMA address of this buffer will be passed to DMA
API’s. While, on QPIC NAND controller, which uses BAM DMA, we read
the controller registers by preparing a BAM command descriptor. This
command descriptor requires the
- controller register address
- the DMA address in which we want to store the value read
back from the controller register.
This command descriptor will be remapped with dma_map_sg
and its DMA address will be passed to DMA API’s. Therefore,
it's required that we also map our register read buffer for
DMA (using dma_map_single). We use the returned DMA address
for preparing entries in our command descriptor.
This patch adds the DMA mapping support for register read
buffer. This buffer will be DMA mapped during allocation
time. Before starting of any operation, this buffer will
be synced for device operation and after operation
completion, it will be synced again for CPU.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.