[PATCH v2 0/2] net: add SpacemiT K1 EMAC support

[Zixian Zeng <sycamoremoon376@gmail.com>]

This series adds support for the Ethernet MACs integrated in
the SpacemiT K1 SoC, which includes adding a k1_emac driver with
MDIO and PHYLIB support for RGMII and RMII operation, enabling it
in the k1 defconfig.

The k1_emac driver in series draws upon Vivian Wang's work [1]. To make it
simple and working, driver which using small ring-buffers operates primarily
on polling and only implements basic functions.

Tested on both Banana Pi F3 Ethernet ports with RTL8211F PHYs
at 1000 Mbps full duplex, and tested command: dhcp, ping, tftp, etc.

[1]: https://lore.kernel.org/all/20250914-net-k1-emac-v12-0-65b31b398f44@iscas.ac.cn/

Signed-off-by: Zixian Zeng <sycamoremoon376@gmail.com>
---
Changes in v2:
- Patch 1: Validate the full DMA range, not only the start address, in
   k1_emac_dma32() (suggested by Dave Klotz)
- Patch 1: Add Tested-by from Dave Klotz
- Drop the MAINTAINERS patch, as the top-level "RISC-V SPACEMIT" entry
   already covers the driver via its N:/K: patterns (suggested by Yixun Lan)
- Link to v1: https://patch.msgid.link/20261002-b4-k1-emac-v1-0-e1b6806b018a@gmail.com

---
Zixian Zeng (2):
       net: k1: add Ethernet MAC driver
       configs: k1: enable Ethernet support

  configs/spacemit_k1_defconfig  |   6 +
  drivers/net/Kconfig            |   1 +
  drivers/net/Makefile           |   1 +
  drivers/net/spacemit/Kconfig   |  15 +
  drivers/net/spacemit/Makefile  |   3 +
  drivers/net/spacemit/k1_emac.c | 957 +++++++++++++++++++++++++++++++++++++++++
  6 files changed, 983 insertions(+)
---
base-commit: ed869863c7e2aca50d57a05d843830dd843138c4
change-id: 20260926-b4-k1-emac-fa5f2b146f38

Best regards,
--
Zixian Zeng <sycamoremoon376@gmail.com>