[PATCH v7 0/3] Determine the number of DMA channels by 'dma-channels' property

From: Zong Li
Date: Mon Mar 07 2022 - 00:44:35 EST


The PDMA driver currently assumes there are four channels by default, it
might cause the error if there is actually less than four channels.
Change that by getting number of channel dynamically from device tree.
For backwards-compatible, it uses the default value (i.e. 4) when there
is no 'dma-channels' information in dts.

This patch set contains the dts and dt-bindings change.

Changed in v7:
- Rebase on tag v5.17-rc7
- Modify the subject of patch

Changed in v6:
- Rebase on tag v5.17-rc6
- Change sf_pdma.chans[] to a flexible array member.

Changed in v5:
- Rebase on tag v5.17-rc3
- Fix typo in dt-bindings and commit message
- Add PDMA versioning scheme for compatible

Changed in v4:
- Remove cflags of debug use reported-by: kernel test robot <lkp@xxxxxxxxx>

Changed in v3:
- Fix allocating wrong size
- Return error if 'dma-channels' is larger than maximum

Changed in v2:
- Rebase on tag v5.16
- Use 4 as default value of dma-channels

Zong Li (3):
dt-bindings: dma-engine: sifive,fu540: Add dma-channels property and
modify compatible
riscv: dts: Add dma-channels property and modify compatible
dmaengine: sf-pdma: Get number of channel by device tree

.../bindings/dma/sifive,fu540-c000-pdma.yaml | 19 +++++++++++++--
.../boot/dts/microchip/microchip-mpfs.dtsi | 3 ++-
arch/riscv/boot/dts/sifive/fu540-c000.dtsi | 3 ++-
drivers/dma/sf-pdma/sf-pdma.c | 24 ++++++++++++-------
drivers/dma/sf-pdma/sf-pdma.h | 8 ++-----
5 files changed, 39 insertions(+), 18 deletions(-)

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2.31.1