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Commit 7dac6f8d authored by David Brownell's avatar David Brownell Committed by Jeff Garzik
Browse files

net/enc28j60: low power mode 



Keep enc28j60 chips in low-power mode when they're not in use.
At typically 120 mA, these chips run hot even when idle; this
low power mode cuts that power usage by a factor of around 100.

This version provides a generic routine to poll a register until
its masked value equals some value ... e.g. bit set or cleared.
It's basically what the previous wait_phy_ready() did, but this
version is generalized to support the handshaking needed to
enter and exit low power mode.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarClaudio Lanconelli <lanconelli.claudio@eptar.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 6fd65882

drivers/net/enc28j60.c

+58 −24
Original line number Original line Diff line number Diff line
@@ -400,26 +400,31 @@ enc28j60_packet_write(struct enc28j60_net *priv, int len, const u8 *data) 
	mutex_unlock(&priv->lock);

	mutex_unlock(&priv->lock);

}

}





/*

static unsigned long msec20_to_jiffies;

 * Wait until the PHY operation is complete.



 */

static int poll_ready(struct enc28j60_net *priv, u8 reg, u8 mask, u8 val)

static int wait_phy_ready(struct enc28j60_net *priv)

{

{

	unsigned long timeout = jiffies + 20 * HZ / 1000;

	unsigned long timeout = jiffies + msec20_to_jiffies;

	int ret = 1;





	/* 20 msec timeout read */

	/* 20 msec timeout read */

	while (nolock_regb_read(priv, MISTAT) & MISTAT_BUSY) {

	while ((nolock_regb_read(priv, reg) & mask) != val) {

		if (time_after(jiffies, timeout)) {

		if (time_after(jiffies, timeout)) {

			if (netif_msg_drv(priv))

			if (netif_msg_drv(priv))

				printk(KERN_DEBUG DRV_NAME

				dev_dbg(&priv->spi->dev,

					": PHY ready timeout!\n");

					"reg %02x ready timeout!\n", reg);

			ret = 0;

			return -ETIMEDOUT;

			break;

		}

		}

		cpu_relax();

		cpu_relax();

	}

	}

	return ret;

	return 0;

}



/*

 * Wait until the PHY operation is complete.

 */

static int wait_phy_ready(struct enc28j60_net *priv)

{

	return poll_ready(priv, MISTAT, MISTAT_BUSY, 0) ? 0 : 1;

}

}





/*

/*
@@ -594,6 +599,32 @@ static void nolock_txfifo_init(struct enc28j60_net *priv, u16 start, u16 end) 
	nolock_regw_write(priv, ETXNDL, end);

	nolock_regw_write(priv, ETXNDL, end);

}

}





/*

 * Low power mode shrinks power consumption about 100x, so we'd like

 * the chip to be in that mode whenever it's inactive.  (However, we

 * can't stay in lowpower mode during suspend with WOL active.)

 */

static void enc28j60_lowpower(struct enc28j60_net *priv, bool is_low)

{

	if (netif_msg_drv(priv))

		dev_dbg(&priv->spi->dev, "%s power...\n",

				is_low ? "low" : "high");



	mutex_lock(&priv->lock);

	if (is_low) {

		nolock_reg_bfclr(priv, ECON1, ECON1_RXEN);

		poll_ready(priv, ESTAT, ESTAT_RXBUSY, 0);

		poll_ready(priv, ECON1, ECON1_TXRTS, 0);

		/* ECON2_VRPS was set during initialization */

		nolock_reg_bfset(priv, ECON2, ECON2_PWRSV);

	} else {

		nolock_reg_bfclr(priv, ECON2, ECON2_PWRSV);

		poll_ready(priv, ESTAT, ESTAT_CLKRDY, ESTAT_CLKRDY);

		/* caller sets ECON1_RXEN */

	}

	mutex_unlock(&priv->lock);

}



static int enc28j60_hw_init(struct enc28j60_net *priv)

static int enc28j60_hw_init(struct enc28j60_net *priv)

{

{

	u8 reg;

	u8 reg;
@@ -612,8 +643,8 @@ static int enc28j60_hw_init(struct enc28j60_net *priv) 
	priv->tx_retry_count = 0;

	priv->tx_retry_count = 0;

	priv->max_pk_counter = 0;

	priv->max_pk_counter = 0;

	priv->rxfilter = RXFILTER_NORMAL;

	priv->rxfilter = RXFILTER_NORMAL;

	/* enable address auto increment */

	/* enable address auto increment and voltage regulator powersave */

	nolock_regb_write(priv, ECON2, ECON2_AUTOINC);

	nolock_regb_write(priv, ECON2, ECON2_AUTOINC | ECON2_VRPS);





	nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);

	nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);

	nolock_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);

	nolock_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);
@@ -690,7 +721,7 @@ static int enc28j60_hw_init(struct enc28j60_net *priv) 




static void enc28j60_hw_enable(struct enc28j60_net *priv)

static void enc28j60_hw_enable(struct enc28j60_net *priv)

{

{

	/* enable interrutps */

	/* enable interrupts */

	if (netif_msg_hw(priv))

	if (netif_msg_hw(priv))

		printk(KERN_DEBUG DRV_NAME ": %s() enabling interrupts.\n",

		printk(KERN_DEBUG DRV_NAME ": %s() enabling interrupts.\n",

			__FUNCTION__);

			__FUNCTION__);
@@ -726,15 +757,12 @@ enc28j60_setlink(struct net_device *ndev, u8 autoneg, u16 speed, u8 duplex) 
	int ret = 0;

	int ret = 0;





	if (!priv->hw_enable) {

	if (!priv->hw_enable) {

		if (autoneg == AUTONEG_DISABLE && speed == SPEED_10) {

		/* link is in low power mode now; duplex setting

		 * will take effect on next enc28j60_hw_init().

		 */

		if (autoneg == AUTONEG_DISABLE && speed == SPEED_10)

			priv->full_duplex = (duplex == DUPLEX_FULL);

			priv->full_duplex = (duplex == DUPLEX_FULL);

			if (!enc28j60_hw_init(priv)) {

		else {

				if (netif_msg_drv(priv))

					dev_err(&ndev->dev,

						"hw_reset() failed\n");

				ret = -EINVAL;

			}

		} else {

			if (netif_msg_link(priv))

			if (netif_msg_link(priv))

				dev_warn(&ndev->dev,

				dev_warn(&ndev->dev,

					"unsupported link setting\n");

					"unsupported link setting\n");
@@ -1307,7 +1335,8 @@ static int enc28j60_net_open(struct net_device *dev) 
		}

		}

		return -EADDRNOTAVAIL;

		return -EADDRNOTAVAIL;

	}

	}

	/* Reset the hardware here */

	/* Reset the hardware here (and take it out of low power mode) */

	enc28j60_lowpower(priv, false);

	enc28j60_hw_disable(priv);

	enc28j60_hw_disable(priv);

	if (!enc28j60_hw_init(priv)) {

	if (!enc28j60_hw_init(priv)) {

		if (netif_msg_ifup(priv))

		if (netif_msg_ifup(priv))
@@ -1337,6 +1366,7 @@ static int enc28j60_net_close(struct net_device *dev) 
		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);

		printk(KERN_DEBUG DRV_NAME ": %s() enter\n", __FUNCTION__);





	enc28j60_hw_disable(priv);

	enc28j60_hw_disable(priv);

	enc28j60_lowpower(priv, true);

	netif_stop_queue(dev);

	netif_stop_queue(dev);





	return 0;

	return 0;
@@ -1537,6 +1567,8 @@ static int __devinit enc28j60_probe(struct spi_device *spi) 
	dev->watchdog_timeo = TX_TIMEOUT;

	dev->watchdog_timeo = TX_TIMEOUT;

	SET_ETHTOOL_OPS(dev, &enc28j60_ethtool_ops);

	SET_ETHTOOL_OPS(dev, &enc28j60_ethtool_ops);





	enc28j60_lowpower(priv, true);



	ret = register_netdev(dev);

	ret = register_netdev(dev);

	if (ret) {

	if (ret) {

		if (netif_msg_probe(priv))

		if (netif_msg_probe(priv))
@@ -1581,6 +1613,8 @@ static struct spi_driver enc28j60_driver = { 




static int __init enc28j60_init(void)

static int __init enc28j60_init(void)

{

{

	msec20_to_jiffies = msecs_to_jiffies(20);



	return spi_register_driver(&enc28j60_driver);

	return spi_register_driver(&enc28j60_driver);

}

}