Low-level Ethernet driver interface for the LPC1768 EMAC. More...

Detailed Description

Low-level Ethernet driver interface for the LPC1768 EMAC.

Author: Bas Stottelaar basst.nosp@m.otte.nosp@m.laar@.nosp@m.gmai.nosp@m.l.com

Definition in file eth.h.

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "iolist.h"

Include dependency graph for eth.h:

int	lpc1768_eth_init (const uint8_t *mac)
	Initialize the EMAC peripheral and PHY.

int	lpc1768_eth_send (const iolist_t *iolist)
	Submit a frame for transmission.

int	lpc1768_eth_recv (void *buf, size_t max_len)
	Receive a frame from the RX ring.

void	lpc1768_eth_get_mac (uint8_t out[6])
	Read the currently programmed MAC address.

void	lpc1768_eth_set_mac (const uint8_t mac[6])
	Program a new MAC address.

bool	lpc1768_eth_link_up (void)
	Read the PHY link status (BMSR.LINK)

bool	lpc1768_eth_rx_pending (void)
	Return true if the RX ring contains at least one unconsumed frame.

int	lpc1768_eth_tx_status (void)
	Query the completion status of the most recent transmission.

void	lpc1768_eth_set_promiscuous (bool enable)
	Enable or disable promiscuous mode.

bool	lpc1768_eth_get_promiscuous (void)
	Return the current promiscuous mode setting.

void	lpc1768_eth_set_link_speed (uint16_t speed)
	Configure the MAC for a given link speed and duplex.

int	lpc1768_eth_start_auto_negotiation (void)
	Start PHY auto-negotiation.

void	lpc1768_eth_complete_auto_negotiation (void)
	Complete auto-negotiation and apply speed/duplex to the MAC.

Function Documentation

◆ lpc1768_eth_complete_auto_negotiation()

void lpc1768_eth_complete_auto_negotiation ( void )

Complete auto-negotiation and apply speed/duplex to the MAC.

Waits until the PHY reports auto-negotiation complete, then derives the negotiated speed and duplex from the advertised and link-partner capability registers and programs SUPP, MAC2, Command and IPGT accordingly.

◆ lpc1768_eth_get_mac()

void lpc1768_eth_get_mac ( uint8_t out[6] )

Read the currently programmed MAC address.

Parameters

[out] out Destination buffer of at least 6 bytes

◆ lpc1768_eth_get_promiscuous()

bool lpc1768_eth_get_promiscuous ( void )

Return the current promiscuous mode setting.

Return values

true	if promiscuous mode is enabled
false	if promiscuous mode is disabled

◆ lpc1768_eth_init()

int lpc1768_eth_init ( const uint8_t * mac )

Initialize the EMAC peripheral and PHY.

Parameters

[in] mac 6-byte MAC address to program into SA0/SA1/SA2

Return values

0	on success
-ENODEV	if the PHY could not be detected
-EIO	if the PHY could not be initialized

◆ lpc1768_eth_link_up()

bool lpc1768_eth_link_up ( void )

Read the PHY link status (BMSR.LINK)

Return values

true	if the link is up
false	if the link is down

◆ lpc1768_eth_recv()

int lpc1768_eth_recv	(	void *	buf,
		size_t	max_len )

Receive a frame from the RX ring.

Behaviour mirrors the netdev recv() contract:

buf == NULL && max_len == 0: return the length of the frame at head.
buf == NULL && max_len > 0 : drop the head frame, return its length.
buf != NULL : copy min(len, max_len) bytes into buf, advance the ring, return the number of bytes copied.

Parameters

[out]	buf	Destination buffer (may be NULL)
[in]	max_len	Capacity of `buf`

Return values

>0	number of bytes successfully received
-ENODATA	if the ring is empty

◆ lpc1768_eth_rx_pending()

bool lpc1768_eth_rx_pending ( void )

Return true if the RX ring contains at least one unconsumed frame.

Return values

true	if at least one frame is pending in the RX ring
false	if the RX ring is empty

◆ lpc1768_eth_send()

int lpc1768_eth_send ( const iolist_t * iolist )

Submit a frame for transmission.

The frame data is gathered from the iolist into the next available TX buffer in AHB SRAM.

Parameters

[in] iolist IO vector list to send

Return values

>0	number of bytes queued for transmission
-EBUSY	on TX descriptor timeout
-EOVERFLOW	if the gathered frame exceeds the MTU

◆ lpc1768_eth_set_link_speed()

void lpc1768_eth_set_link_speed ( uint16_t speed )

Configure the MAC for a given link speed and duplex.

Programs the SUPP, MAC2, Command and IPGT registers to match the requested speed and duplex. Used both to apply a statically configured link speed and to apply the result of auto-negotiation.

Parameters

[in] speed bitmask of MII BMCR speed/duplex bits (MII_BMCR_SPEED_100, MII_BMCR_FULL_DPLX)

◆ lpc1768_eth_set_mac()

void lpc1768_eth_set_mac ( const uint8_t mac[6] )

Program a new MAC address.

Parameters

[in] mac 6-byte MAC address to set

◆ lpc1768_eth_set_promiscuous()

void lpc1768_eth_set_promiscuous ( bool enable )

Enable or disable promiscuous mode.

Parameters

[in] enable true to enable promiscuous mode, false to disable

◆ lpc1768_eth_start_auto_negotiation()

int lpc1768_eth_start_auto_negotiation ( void )

Start PHY auto-negotiation.

Advertises all 10/100 Mbps half- and full-duplex capabilities and restarts auto-negotiation on the PHY. The negotiation runs asynchronously: call lpc1768_eth_complete_auto_negotiation once the link is up to apply the negotiated parameters to the MAC.

Return values

0	on success
-EOPNOTSUPP	if the PHY does not support auto-negotiation

◆ lpc1768_eth_tx_status()

int lpc1768_eth_tx_status ( void )

Query the completion status of the most recent transmission.

Checks whether the descriptor queued by the most recent lpc1768_eth_send has been consumed by the EMAC and, if so, inspects its transmit status word.

This method must only be called after a transmission was started by lpc1768_eth_send. The return value is only valid for the most recent transmission.

Return values

>0	number of bytes successfully transmitted
-EAGAIN	if the frame is still being transmitted
-EBUSY	if the frame was aborted due to a collision
-EIO	if the frame failed for any other reason