ra8_eth_media.c File Reference

ESWM media mux: select a port's MII/RGMII mode and release its block. More...

#include "ra8_check.h"
#include "ra8_err.h"
#include "ra8_eth.h"
#include "ra8_ether_regs.h"
#include "ra8_log.h"

Include dependency graph for ra8_eth_media.c:

Go to the source code of this file.

Functions
ra8_err_t	ra8_eth_rgmii_select (ra8_eth_mii_port_t port)
	Select RGMII on a port's ESWM media-interface mux and enable it.

Detailed Description

ESWM media mux: select a port's MII/RGMII mode and release its block.

Tag

[Ring 2 / HAL] {World: S}

The media half of the Ethernet HAL, kept apart from the frame-level NIC API in ra8_eth.c. Choosing how a port talks to its PHY, and taking that port's interface block out of reset, happens once during bring-up and has nothing in common with opening a NIC or moving frames – and ra8_eth.c had grown to the 1000-line cap, which the file-size policy answers by splitting a responsibility rather than by granting a waiver.

Copyright

Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Definition in file ra8_eth_media.c.

Function Documentation

ra8_eth_rgmii_select()

ra8_err_t ra8_eth_rgmii_select ( ra8_eth_mii_port_t port )

nodiscard

Select RGMII on a port's ESWM media-interface mux and enable it.

The chip-generic ESWM RGMII media-select every RA8 RGMII board runs once during Ethernet bring-up. After power-on reset MIICRm.MIISEL reads 0 (GMII/MII) and MIIRR.RGRSTm reads 0 (RGMII block held in reset), so the RGMII data path is dead until the driver explicitly:

1. Sets MIICRm = MIISEL = RGMII (01b) | TXCIDE (on-chip TX clock delay), matching the FSP "RGMII + 2 ns TX skew" board profile.
2. Sets MIIRR.RGRSTm = 1. HUM Ch 29.2.1.2: RGRSTm is 1 = Enable, 0 = Reset – an ENABLE bit, not an active-high reset. Without it TXC is never generated and the RMAC RX state machine is unclocked, so every RMAC RX counter stays at 0.

It previously lived open-coded in the EK-RA8D2 board Ethernet bring-up; the accesses are chip-generic, so they belong here in the HAL. Which port is wired, and any board TX/RX skew choices in the PHY, remain board concerns.

Parameters

[in]

port

ESWM media-interface port to route to RGMII. Must be a valid ra8_eth_mii_port_t (< k_ra8_eth_mii_port_count).

Returns

ra8_err_t Result code.

Return values

k_ra8_ok	Port routed to RGMII and its block enabled.
k_ra8_err_invalid_arg	port is out of range.

Precondition

The ESWM module-stop gate (k_ra8_mstp_eswm) has been released.

COMA has been brought up (ra8_eth_coma_bringup) so the media window is accessible.

Postcondition

On success MIICRport = TXCIDE | RGMII and MIIRR.RGRSTport = 1.

On k_ra8_err_invalid_arg no register was written.

Note

Not thread-safe; call from a single-threaded init context.

eth is HW-blocked on silicon (issue #21); this path is host-tested and sim-modeled, not hardware-validated.

Example:

(void)ra8_eth_coma_bringup();
(void)ra8_eth_rgmii_select(k_ra8_eth_mii_port_1);  // EK-RA8D2 RJ45 = port 1

See also

ra8_eth_coma_bringup

Since

0.1.0

Log tag – block scope: this is the only function here that logs.

Definition at line 26 of file ra8_eth_media.c.

References k_ra8_err_invalid_arg, k_ra8_eswm_miicr_miisel_rgmii, k_ra8_eswm_miicr_txcide, k_ra8_eswm_miirr_rgrst0, k_ra8_eswm_miirr_rgrst1, k_ra8_eth_mii_port_0, k_ra8_eth_mii_port_1, k_ra8_ok, RA8_CHECK_RANGE_TAG, ra8_eswm_miicr0(), ra8_eswm_miicr1(), ra8_eswm_miirr(), and ra8_log_info.

Referenced by ehb_run_once(), and ra8_board_ethernet_init().