[v3,0/3] Determine the number of DMA channels by 'dma-channels' property

Message

Zong Li Jan. 14, 2022, 9:17 a.m. UTC

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 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):
  riscv: dts: Add dma-channels property in dma node
  dt-bindings: Add dma-channels for pdma device node
  dmaengine: sf-pdma: Get number of channel by device tree

 .../bindings/dma/sifive,fu540-c000-pdma.yaml  |  7 +++++++
 .../boot/dts/microchip/microchip-mpfs.dtsi    |  1 +
 arch/riscv/boot/dts/sifive/fu540-c000.dtsi    |  1 +
 drivers/dma/sf-pdma/Makefile                  |  2 ++
 drivers/dma/sf-pdma/sf-pdma.c                 | 20 ++++++++++++-------
 drivers/dma/sf-pdma/sf-pdma.h                 |  8 ++------
 6 files changed, 26 insertions(+), 13 deletions(-)