dmaengine: ste_dma40: Fix V4B event group mapping

DMA40 physical resources are connected in pairs to event groups. The
mapping repeats after each complete set of groups.

D40_GROUP_SIZE and D40_PHYS_TO_GROUP() encode the four-group V4A layout.
On V4B, which has five groups, resources 8 and 9 are consequently offered
both to event groups 0 and 4. The GCC clock bookkeeping also treats these
resources as group 0 instead of group 4.

Derive the physical-resource stride and reverse mapping from the
variant-specific number of event groups. This preserves the V4A mapping
and gives V4B a ten-resource stride: resources 8 and 9 belong only to
group 4, while resources 10 and 11 repeat group 0.

Fixes: 3cb645dc85a0 ("dmaengine: ste_dma40: support more than 128 event lines")
Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260927-dma40-fixes-v7-21-89f595e8851d@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

0 files changed, 0 insertions, 0 deletions