From 7dac6f8df607929e51f4fd598d80bd009c45a9f8 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Thu, 12 Jun 2008 21:38:06 -0700 Subject: 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: David Brownell Signed-off-by: Claudio Lanconelli Signed-off-by: Jeff Garzik --- drivers/net/enc28j60.c | 82 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 58 insertions(+), 24 deletions(-) (limited to 'drivers') diff --git a/drivers/net/enc28j60.c b/drivers/net/enc28j60.c index 0f1581cbd101..c05cb159c772 100644 --- a/drivers/net/enc28j60.c +++ b/drivers/net/enc28j60.c @@ -400,26 +400,31 @@ enc28j60_packet_write(struct enc28j60_net *priv, int len, const u8 *data) mutex_unlock(&priv->lock); } -/* - * Wait until the PHY operation is complete. - */ -static int wait_phy_ready(struct enc28j60_net *priv) +static unsigned long msec20_to_jiffies; + +static int poll_ready(struct enc28j60_net *priv, u8 reg, u8 mask, u8 val) { - unsigned long timeout = jiffies + 20 * HZ / 1000; - int ret = 1; + unsigned long timeout = jiffies + msec20_to_jiffies; /* 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 (netif_msg_drv(priv)) - printk(KERN_DEBUG DRV_NAME - ": PHY ready timeout!\n"); - ret = 0; - break; + dev_dbg(&priv->spi->dev, + "reg %02x ready timeout!\n", reg); + return -ETIMEDOUT; } 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); } +/* + * 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) { u8 reg; @@ -612,8 +643,8 @@ static int enc28j60_hw_init(struct enc28j60_net *priv) priv->tx_retry_count = 0; priv->max_pk_counter = 0; priv->rxfilter = RXFILTER_NORMAL; - /* enable address auto increment */ - nolock_regb_write(priv, ECON2, ECON2_AUTOINC); + /* enable address auto increment and voltage regulator powersave */ + nolock_regb_write(priv, ECON2, ECON2_AUTOINC | ECON2_VRPS); nolock_rxfifo_init(priv, RXSTART_INIT, RXEND_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) { - /* enable interrutps */ + /* enable interrupts */ if (netif_msg_hw(priv)) printk(KERN_DEBUG DRV_NAME ": %s() enabling interrupts.\n", __FUNCTION__); @@ -726,15 +757,12 @@ enc28j60_setlink(struct net_device *ndev, u8 autoneg, u16 speed, u8 duplex) int ret = 0; 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); - if (!enc28j60_hw_init(priv)) { - if (netif_msg_drv(priv)) - dev_err(&ndev->dev, - "hw_reset() failed\n"); - ret = -EINVAL; - } - } else { + else { if (netif_msg_link(priv)) dev_warn(&ndev->dev, "unsupported link setting\n"); @@ -1307,7 +1335,8 @@ static int enc28j60_net_open(struct net_device *dev) } 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); if (!enc28j60_hw_init(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__); enc28j60_hw_disable(priv); + enc28j60_lowpower(priv, true); netif_stop_queue(dev); return 0; @@ -1537,6 +1567,8 @@ static int __devinit enc28j60_probe(struct spi_device *spi) dev->watchdog_timeo = TX_TIMEOUT; SET_ETHTOOL_OPS(dev, &enc28j60_ethtool_ops); + enc28j60_lowpower(priv, true); + ret = register_netdev(dev); if (ret) { if (netif_msg_probe(priv)) @@ -1581,6 +1613,8 @@ static struct spi_driver enc28j60_driver = { static int __init enc28j60_init(void) { + msec20_to_jiffies = msecs_to_jiffies(20); + return spi_register_driver(&enc28j60_driver); } -- cgit v1.2.3