at91_ether.c

RT-Thread是发展中的下一代微内核嵌入式实时操作系统

/*
 * Ethernet driver for the Atmel AT91RM9200
 * Based on NetBSD AT91 EMAC driver
 */

#include <rthw.h>
#include <rtthread.h>

#include <AT9200.h>
#include <mii.h>
#include <ethtool.h>
#include <AT91RM9200_EMAC.h>
#include <pio.h>
#include <at91_ether.h>
#include <ethernetif.h>

#define barrier() __asm__ __volatile__("": : :"memory")
#define CONFIG_AT91_ETHER_RMII

/* Davicom specific registers */
#define MII_DSCSR_REG   17
#define MII_DSINTR_REG  21

AT91PS_SYS AT91_SYS = (AT91PS_SYS) AT91C_BASE_SYS;
AT91PS_EMAC AT91_EMAC = (AT91PS_EMAC) AT91C_BASE_EMAC;

#define MAX_ADDR_LEN 6
struct net_device_stats
{
	unsigned long rx_packets;		/* total packets received	*/
	unsigned long tx_packets;		/* total packets transmitted	*/
	unsigned long rx_errors;		/* receive bad packets */
	unsigned long tx_errors;		/* transmit bad packets */
};
#define	IFF_PROMISC		0x100		/* receive all packets		*/
#define	IFF_ALLMULTI	0x200		/* receive all multicast packets*/
#define PHY_IRQ			32
#define MAX_RBUFF_SZ	0x600		/* 1518 rounded up */
#define MAX_RX_DESCR	9			/* max number of receive buffers */

struct rbf_t
{
	rt_uint32_t addr;
	rt_uint32_t size;
};

struct net_device
{
	/* inherit from ethernet device */
	struct eth_device parent;

	int state ;
	rt_uint32_t current_rb_index;				/* current receive buffer index */

	/* interface address info. */
	rt_uint8_t  dev_addr[MAX_ADDR_LEN];			/* hw address	*/
	rt_uint8_t  phy_addr;

	struct rbf_t 	descriptors[MAX_RX_DESCR];			/* must be on sizeof (rbf_t) boundary */
	rt_uint8_t 		rx_buf[MAX_RX_DESCR][MAX_RBUFF_SZ];	/* must be on long boundary */
	rt_uint8_t 		tx_buf[MAX_RBUFF_SZ];				/* must be on long boundary */

	struct net_device_stats stats;
};

static struct net_device  at91_dev_entry;
static struct net_device *at91_dev =&at91_dev_entry;

/* ........................... PHY INTERFACE ........................... */

/*
 * Write value to the a PHY register
 * Note: MDI interface is assumed to already have been enabled.
 */
rt_inline void write_phy(rt_uint8_t phy_addr, rt_uint8_t address, rt_uint32_t value)
{
	AT91_EMAC->EMAC_MAN = (AT91C_EMAC_HIGH | AT91C_EMAC_CODE_802_3 | AT91C_EMAC_RW_W
					  |((phy_addr & 0x1f) << 23)| (address << 18)) + (value & 0xffff);

	/* Wait until IDLE bit in Network Status register is cleared */
	// TODO: Enforce some maximum loop-count?
	while (!(AT91_EMAC->EMAC_SR & AT91C_EMAC_IDLE))
	{
		barrier();
	}
}

/*
 * Read value stored in a PHY register.
 * Note: MDI interface is assumed to already have been enabled.
 */
rt_inline void read_phy(rt_uint8_t phy_addr, rt_uint8_t address, rt_uint32_t *value)
{
	AT91_EMAC->EMAC_MAN = AT91C_EMAC_HIGH | AT91C_EMAC_CODE_802_3 | AT91C_EMAC_RW_R
					 |((phy_addr & 0x1f) << 23)| (address << 18);

	/* Wait until IDLE bit in Network Status register is cleared */
	// TODO: Enforce some maximum loop-count?
	while (!(AT91_EMAC->EMAC_SR & AT91C_EMAC_IDLE))
	{
		barrier();
	}

	*value = (AT91_EMAC->EMAC_MAN & 0x0000ffff);
}

/* ........................... PHY MANAGEMENT .......................... */

/*
 * Access the PHY to determine the current Link speed and Mode, and update the
 * MAC accordingly.
 * If no link or auto-negotiation is busy, then no changes are made.
 * Returns:  0 : OK
 *          -1 : No link
 *          -2 : AutoNegotiation still in progress
 */
static int update_linkspeed(struct net_device *dev)
{
	rt_uint32_t bmsr, bmcr, lpa, mac_cfg;
	rt_uint32_t speed, duplex;

	/* Link up, or auto-negotiation still in progress */
	read_phy(dev->phy_addr ,MII_BMSR, &bmsr);
	read_phy(dev->phy_addr ,MII_BMSR, &bmsr);
	if (!(bmsr & BMSR_LSTATUS))
		return -1;			/* no link */

	read_phy(dev->phy_addr, MII_BMCR, &bmcr);

	if (bmcr & BMCR_ANENABLE)
	{				/* AutoNegotiation is enabled */
		if (!(bmsr & BMSR_ANEGCOMPLETE)) return -2;	/* auto-negotitation in progress */

		read_phy(dev->phy_addr, MII_LPA, &lpa);

		if ((lpa & LPA_100FULL) || (lpa & LPA_100HALF)) speed = SPEED_100;
		else speed = SPEED_10;
		if ((lpa & LPA_100FULL) || (lpa & LPA_10FULL)) duplex = DUPLEX_FULL;
		else duplex = DUPLEX_HALF;
	}
	else
	{
		speed = (bmcr & BMCR_SPEED100) ? SPEED_100 : SPEED_10;
		duplex = (bmcr & BMCR_FULLDPLX) ? DUPLEX_FULL : DUPLEX_HALF;
	}

	/* Update the MAC */
	mac_cfg = AT91_EMAC->EMAC_CFG & ~(AT91C_EMAC_SPD | AT91C_EMAC_FD);
	if (speed == SPEED_100)
	{
		if (duplex == DUPLEX_FULL)		/* 100 Full Duplex */
			AT91_EMAC->EMAC_CFG = mac_cfg | AT91C_EMAC_SPD | AT91C_EMAC_FD;
		else					/* 100 Half Duplex */
			AT91_EMAC->EMAC_CFG = mac_cfg | AT91C_EMAC_SPD;
	}
	else
	{
		if (duplex == DUPLEX_FULL)		/* 10 Full Duplex */
			AT91_EMAC->EMAC_CFG = mac_cfg | AT91C_EMAC_FD;
		else					/* 10 Half Duplex */
			AT91_EMAC->EMAC_CFG = mac_cfg;
	}

	return 0;
}

void netif_carrier_off(struct net_device *dev )
{
	dev->state = 0;
}

void netif_carrier_on(struct net_device *dev )
{
	dev->state = 1;
}

/*
 * Handle interrupts from the PHY
 */
void at91ether_phy_interrupt(int irq)
{
	int status;
	rt_uint32_t phy;

	AT91_EMAC->EMAC_CTL |= AT91C_EMAC_MPE;	/* enable management port */

	read_phy(at91_dev->phy_addr, MII_DSINTR_REG, &phy);	/* acknowledge interrupt in PHY */
	status = AT91_SYS->PIOC_ISR;		/* acknowledge interrupt in PIO */

	status = update_linkspeed(at91_dev);
	if (status == -1)
	{		/* link is down */
		netif_carrier_off(at91_dev);
	}
	else if (status == -2)
	{		/* auto-negotiation in progress */
		/* Do nothing - another interrupt generated when negotiation complete */
	}
	else
	{		/* link is operational */
		netif_carrier_on(at91_dev);
	}

	AT91_EMAC->EMAC_CTL &= ~AT91C_EMAC_MPE;	/* disable management port */
}

/*
 * Initialize and enable the PHY interrupt when link-state changes
 */
void enable_phyirq(struct net_device *dev)
{
	static int first_init = 0;

	if (first_init == 0)
	{
		// TODO: Check error code.  Really need a generic PIO (interrupt)
		// layer since we're really only interested in the PC4 line.
		rt_hw_interrupt_install(PHY_IRQ, at91ether_phy_interrupt, 0);
		rt_hw_interrupt_umask(PHY_IRQ);

		AT91_SYS->PIOC_ODR = AT91C_PIO_PC4;	/* Configure as input */

		first_init = 1;
	}
	else
	{
		rt_uint32_t dsintr, status;
		status = AT91_SYS->PIOC_ISR;		/* clear any pending PIO interrupts */
		AT91_SYS->PIOC_IER = AT91C_PIO_PC4;	/* Enable interrupt */

		AT91_EMAC->EMAC_CTL |= AT91C_EMAC_MPE;	/* enable management port */
		read_phy(dev->phy_addr, MII_DSINTR_REG, &dsintr);
		dsintr = dsintr & ~0xf00;		/* clear bits 8..11 */
		write_phy(dev->phy_addr,MII_DSINTR_REG, dsintr);
		AT91_EMAC->EMAC_CTL &= ~AT91C_EMAC_MPE;	/* disable management port */
	}
}

/*
 * Disable the PHY interrupt
 */
void disable_phyirq(struct net_device *dev)
{
	rt_uint32_t dsintr;
	rt_base_t level;

	level = rt_hw_interrupt_disable();
	AT91_EMAC->EMAC_CTL |= AT91C_EMAC_MPE;	/* enable management port */
	read_phy(dev->phy_addr, MII_DSINTR_REG, &dsintr);
	dsintr = dsintr | 0xf00;			/* set bits 8..11 */
	write_phy(dev->phy_addr, MII_DSINTR_REG, dsintr);
	AT91_EMAC->EMAC_CTL &= ~AT91C_EMAC_MPE;	/* disable management port */
	rt_hw_interrupt_enable(level);

	AT91_SYS->PIOC_IDR = AT91C_PIO_PC4;		/* Disable interrupt */
}

/**
 * is_valid_ether_addr - Determine if the given Ethernet address is valid
 * @addr: Pointer to a six-byte array containing the Ethernet address
 *
 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 * a multicast address, and is not FF:FF:FF:FF:FF:FF.  The multicast
 * and FF:FF:... tests are combined into the single test "!(addr[0]&1)".
 *
 * Return true if the address is valid.
 */
rt_inline int is_valid_ether_addr(rt_uint8_t *addr)
{
	const char zaddr[6] ={ 0, };

	return !(addr[0]&1) && rt_memcmp( addr, zaddr, 6);
}

/* ......................... ADDRESS MANAGEMENT ........................ */
/*
 * Set the ethernet MAC address in dev->dev_addr
 */
void get_mac_address(struct net_device *dev)
{
	static rt_uint8_t def_mac[] = {0x00,0xaa,0xbb,0xcc,0xdd,0x00};
	rt_uint8_t addr[6];
	rt_uint32_t hi, lo;

	/* Check if bootloader set address in Specific-Address 1 */
	hi = AT91_EMAC->EMAC_SA1H;
	lo = AT91_EMAC->EMAC_SA1L;
	addr[0] = (lo & 0xff);
	addr[1] = (lo & 0xff00) >> 8;
	addr[2] = (lo & 0xff0000) >> 16;
	addr[3] = (lo & 0xff000000) >> 24;
	addr[4] = (hi & 0xff);
	addr[5] = (hi & 0xff00) >> 8;

	if (is_valid_ether_addr(addr))
	{
		rt_memcpy(dev->dev_addr, &addr, 6);
		return;
	}

	/* Check if bootloader set address in Specific-Address 2 */
	hi = AT91_EMAC->EMAC_SA2H;
	lo = AT91_EMAC->EMAC_SA2L;
	addr[0] = (lo & 0xff);
	addr[1] = (lo & 0xff00) >> 8;
	addr[2] = (lo & 0xff0000) >> 16;
	addr[3] = (lo & 0xff000000) >> 24;
	addr[4] = (hi & 0xff);
	addr[5] = (hi & 0xff00) >> 8;

	if (is_valid_ether_addr(addr))
	{
		rt_memcpy(dev->dev_addr, &addr, 6);
		return;
	}

	rt_memcpy(dev->dev_addr,&def_mac,6);
	return;
}

/*