mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-07-22 01:08:13 -04:00
c0a207898f
Some peripherals on RZ/G3E SoCs (SSIU, SPDIF, SCU/SRC, DVC, PFC) require
explicit ACK signal routing through the ICU for level-based DMA handshaking.
Rather than extending the DT binding with an optional second #dma-cells
(which would require all DMA consumers to supply two cells even when ACK
routing is not needed), derive the ACK signal number directly from the
MID/RID request number using the linear mapping defined in RZ/G3E hardware
manual Table 4.6-28:
PFC external DMA pins (DREQ0..DREQ4):
req_no 0x000-0x004 -> ACK No. 84-88
SSIU BUSIFs (ssip00..ssip93):
req_no 0x161-0x198 -> ACK No. 28-83
SPDIF (CH0..CH2) + SCU SRC (sr0..sr9) + DVC (cmd0..cmd1):
req_no 0x199-0x1b4 -> ACK No. 0-27
ACK routing is programmed when a channel is prepared for transfer and
cleared when the channel is released or the transfer times out, following
the same pattern as MID/RID request routing.
Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
Link: https://patch.msgid.link/20260525110750.4020112-3-john.madieu.xa@bp.renesas.com
[fixes subsystem name tag]
Signed-off-by: Vinod Koul <vkoul@kernel.org>