[RFC PATCH net-next v4 0/3] Add DWMAC glue driver for Motorcomm YT6801

Yao Zi
2025-12-16T18:11:08Z

This series adds glue driver for Motorcomm YT6801 PCIe ethernet
controller, which is considered mostly compatible with DWMAC-4 IP by
inspecting the register layout[1]. It integrates a Motorcomm YT8531S PHY
(confirmed by reading PHY ID) and GMII is used to connect the PHY to
MAC[2].

The initialization logic of the MAC is mostly based on previous upstream
effort for the controller[3] and the Deepin-maintained downstream Linux
driver[4] licensed under GPL-2.0 according to its SPDX headers. However,
this series is a completely re-write of the previous patch series,
utilizing the existing DWMAC4 driver and introducing a glue driver only.

This series only aims to add basic networking functions for the
controller, features like WoL, RSS and LED control are omitted for now.
Testing is done on Loongson 3A5000 machine. Through a local GbE switch,
it reaches 872Mbps (TX)/942Mbps (RX) on average,

YT6801 TX

Connecting to host 172.16.70.12, port 5201
[ 5] local 172.16.70.230 port 53658 connected to 172.16.70.12 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 104 MBytes 869 Mbits/sec 0 533 KBytes
[ 5] 1.00-2.00 sec 104 MBytes 875 Mbits/sec 0 533 KBytes
[ 5] 2.00-3.00 sec 104 MBytes 874 Mbits/sec 0 533 KBytes
[ 5] 3.00-4.00 sec 104 MBytes 870 Mbits/sec 0 533 KBytes
[ 5] 4.00-5.00 sec 104 MBytes 874 Mbits/sec 0 533 KBytes
[ 5] 5.00-6.00 sec 104 MBytes 874 Mbits/sec 0 533 KBytes
[ 5] 6.00-7.00 sec 104 MBytes 870 Mbits/sec 0 533 KBytes
[ 5] 7.00-8.00 sec 103 MBytes 866 Mbits/sec 0 533 KBytes
[ 5] 8.00-9.00 sec 104 MBytes 872 Mbits/sec 0 533 KBytes
[ 5] 9.00-10.00 sec 104 MBytes 871 Mbits/sec 0 533 KBytes

YT6801 RX

Connecting to host 172.16.70.230, port 5201
[ 5] local 172.16.70.12 port 45596 connected to 172.16.70.230 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 114 MBytes 955 Mbits/sec 0 427 KBytes
[ 5] 1.00-2.00 sec 112 MBytes 942 Mbits/sec 0 427 KBytes
[ 5] 2.00-3.00 sec 112 MBytes 937 Mbits/sec 0 427 KBytes
[ 5] 3.00-4.00 sec 112 MBytes 940 Mbits/sec 0 427 KBytes
[ 5] 4.00-5.00 sec 113 MBytes 945 Mbits/sec 0 427 KBytes
[ 5] 5.00-6.00 sec 112 MBytes 940 Mbits/sec 0 427 KBytes
[ 5] 6.00-7.00 sec 113 MBytes 947 Mbits/sec 0 427 KBytes
[ 5] 7.00-8.00 sec 112 MBytes 935 Mbits/sec 0 427 KBytes
[ 5] 8.00-9.00 sec 113 MBytes 945 Mbits/sec 0 427 KBytes
[ 5] 9.00-10.00 sec 112 MBytes 938 Mbits/sec 0 427 KBytes

Thanks for your time and review.

[1]: https://lore.kernel.org/all/Z_T6vv013jraCzSD@shell.armlinux.org.uk/
[2]: https://lore.kernel.org/all/a48d76ac-db08-46d5-9528-f046a7b541dc@motor-comm.com/
[3]: https://lore.kernel.org/all/a48d76ac-db08-46d5-9528-f046a7b541dc@motor-comm.com/
[4]: https://github.com/deepin-community/kernel/tree/dc61248a0e21/drivers/net/ethernet/motorcomm/yt6801

Changed from v3
- Manually register a devres action to call pci_free_irq_vectors(),
instead of relying on the obsolete behavior of
pci_alloc_irq_vectors().
- Remove redundant call to pci_free_irq_vectors() in remove callback.
- Use my new mail address me@ziyao.cc for Sign-off-by and commit author.
- Link to v3: https://lore.kernel.org/netdev/20251124163211.54994-1-ziyao@disroot.org/

Changed from v2
- Rebase on top of next-20251124
- Switch to stmmac_plat_dat_alloc() then drop now redundant parameters
from motorcomm_default_plat_data()
- Set STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP
- Add a comment indicating the possible source of CSR clock
- Link to v2: https://lore.kernel.org/netdev/20251111105252.53487-1-ziyao@disroot.org/

Changed from v1
- Drop (original) PATCH 1, add no vendor ID entry to linux/pci_ids.h
- Use PHY_INTERFACE_MODE_GMII instead of PHY_INTERFACE_MODE_INTERNAL
- Drop extra register read in motorcomm_efuse_read_byte()
- Rename EPHY_RESET to EPHY_MDIO_PHY_RESET, add a comment to reflect its
function better
- Use the newly-introduced generic PCI suspend/resume routines
- Generate a random MAC address instead of failing to probe when no MAC
address is programmed in eFuse (seen on some OEM EVBs).
- Collect Tested-by tags
- Link to v1: https://lore.kernel.org/netdev/20251014164746.50696-2-ziyao@disroot.org/

Yao Zi (3):
net: phy: motorcomm: Support YT8531S PHY in YT6801 Ethernet controller
net: stmmac: Add glue driver for Motorcomm YT6801 ethernet controller
MAINTAINERS: Assign myself as maintainer of Motorcomm DWMAC glue
driver

MAINTAINERS | 6 +
drivers/net/ethernet/stmicro/stmmac/Kconfig | 9 +
drivers/net/ethernet/stmicro/stmmac/Makefile | 1 +
.../ethernet/stmicro/stmmac/dwmac-motorcomm.c | 383 ++++++++++++++++++
drivers/net/phy/motorcomm.c | 4 +
5 files changed, 403 insertions(+)
create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-motorcomm.c

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2.51.2