From: Guomin Chen <Guomin.Chen@cixtech.com>

The Cixtech mailbox controller, used in the Cixtech Sky1 SoC,
is used for message transmission between multiple processors
within the SoC, such as the AP, PM, audio DSP, SensorHub MCU,
and others.

The Cixtech mailbox is unidirectional, so it typically operates in
pairs—one for reading and one for writing.

Each Cixtech mailbox supports 11 channels with different transmission
modes:
 channel 0-7 - Fast channel with 32bit transmit register and IRQ support
 channel 8   - Doorbell mode,using the mailbox as an interrupt-generating
                mechanism.
 channel 9   - Fifo based channel with 32*32bit depth fifo and IRQ support
 channel 10  - Reg based channel with 32*32bit transmit register and
                Doorbell+transmit acknowledgment IRQ support

Changes for v2:
- Update the Subject title.
- Rename the bindings file to be based on compatible: cix,sky1-mbox

---
Guomin Chen (2):
  dt-bindings: mailbox: add cix,sky1-mbox
  mailbox: add Cixtech mailbox driver

 .../bindings/mailbox/cix,sky1-mbox.yaml       |  80 +++
 drivers/mailbox/Kconfig                       |  10 +
 drivers/mailbox/Makefile                      |   2 +
 drivers/mailbox/cixtech-mailbox.c             | 633 ++++++++++++++++++
 4 files changed, 725 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/cix,sky1-mbox.yaml
 create mode 100644 drivers/mailbox/cixtech-mailbox.c

-- 
2.34.1