net: phy: broadcom: Add support for Wake-on-LAN

Add support for WAKE_UCAST, WAKE_MCAST, WAKE_BCAST, WAKE_MAGIC and
WAKE_MAGICSECURE. This is only supported with the BCM54210E and
compatible Ethernet PHYs. Using the in-band interrupt or an out of band
GPIO interrupts are supported.

Broadcom PHYs will generate a Wake-on-LAN level low interrupt on LED4 as
soon as one of the supported patterns is being matched. That includes
generating such an interrupt even if the PHY is operated during normal
modes. If WAKE_UCAST is selected, this could lead to the LED4 interrupt
firing up for every packet being received which is absolutely
undesirable from a performance point of view.

Because the Wake-on-LAN configuration can be set long before the system
is actually put to sleep, we cannot have an interrupt service routine to
clear on read the interrupt status register and ensure that new packet
matches will be detected.

It is desirable to enable the Wake-on-LAN interrupt as late as possible
during the system suspend process such that we limit the number of
interrupts to be handled by the system, but also conversely feed into
the Linux's system suspend way of dealing with interrupts in and around
the points of no return.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 123 insertions, 3 deletions

diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c
index ad71c88c87e7..418e6bc0e998 100644
--- a/drivers/net/phy/broadcom.c
+++ b/drivers/net/phy/broadcom.c
@@ -14,8 +14,12 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/phy.h>
+#include <linux/pm_wakeup.h>
 #include <linux/brcmphy.h>
 #include <linux/of.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/gpio/consumer.h>
 
 #define BRCM_PHY_MODEL(phydev) \
 	((phydev)->drv->phy_id & (phydev)->drv->phy_id_mask)
@@ -30,8 +34,17 @@ MODULE_LICENSE("GPL");
 struct bcm54xx_phy_priv {
 	u64	*stats;
 	struct bcm_ptp_private *ptp;
+	int	wake_irq;
+	bool	wake_irq_enabled;
 };
 
+static bool bcm54xx_phy_can_wakeup(struct phy_device *phydev)
+{
+	struct bcm54xx_phy_priv *priv = phydev->priv;
+
+	return phy_interrupt_is_valid(phydev) || priv->wake_irq >= 0;
+}
+
 static int bcm54xx_config_clock_delay(struct phy_device *phydev)
 {
 	int rc, val;
@@ -413,6 +426,16 @@ static int bcm54xx_config_init(struct phy_device *phydev)
 
 	bcm54xx_ptp_config_init(phydev);
 
+	/* Acknowledge any left over interrupt and charge the device for
+	 * wake-up.
+	 */
+	err = bcm_phy_read_exp(phydev, BCM54XX_WOL_INT_STATUS);
+	if (err < 0)
+		return err;
+
+	if (err)
+		pm_wakeup_event(&phydev->mdio.dev, 0);
+
 	return 0;
 }
 
@@ -437,12 +460,39 @@ out:
 	return ret;
 }
 
+static int bcm54xx_set_wakeup_irq(struct phy_device *phydev, bool state)
+{
+	struct bcm54xx_phy_priv *priv = phydev->priv;
+	int ret = 0;
+
+	if (!bcm54xx_phy_can_wakeup(phydev))
+		return ret;
+
+	if (priv->wake_irq_enabled != state) {
+		if (state)
+			ret = enable_irq_wake(priv->wake_irq);
+		else
+			ret = disable_irq_wake(priv->wake_irq);
+		priv->wake_irq_enabled = state;
+	}
+
+	return ret;
+}
+
 static int bcm54xx_suspend(struct phy_device *phydev)
 {
-	int ret;
+	int ret = 0;
 
 	bcm54xx_ptp_stop(phydev);
 
+	/* Acknowledge any Wake-on-LAN interrupt prior to suspend */
+	ret = bcm_phy_read_exp(phydev, BCM54XX_WOL_INT_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if (phydev->wol_enabled)
+		return bcm54xx_set_wakeup_irq(phydev, true);
+
 	/* We cannot use a read/modify/write here otherwise the PHY gets into
 	 * a bad state where its LEDs keep flashing, thus defeating the purpose
 	 * of low power mode.
@@ -456,7 +506,13 @@ static int bcm54xx_suspend(struct phy_device *phydev)
 
 static int bcm54xx_resume(struct phy_device *phydev)
 {
-	int ret;
+	int ret = 0;
+
+	if (phydev->wol_enabled) {
+		ret = bcm54xx_set_wakeup_irq(phydev, false);
+		if (ret)
+			return ret;
+	}
 
 	ret = bcm54xx_iddq_set(phydev, false);
 	if (ret < 0)
@@ -801,14 +857,54 @@ static int brcm_fet_suspend(struct phy_device *phydev)
 	return err;
 }
 
+static void bcm54xx_phy_get_wol(struct phy_device *phydev,
+				struct ethtool_wolinfo *wol)
+{
+	/* We cannot wake-up if we do not have a dedicated PHY interrupt line
+	 * or an out of band GPIO descriptor for wake-up. Zeroing
+	 * wol->supported allows the caller (MAC driver) to play through and
+	 * offer its own Wake-on-LAN scheme if available.
+	 */
+	if (!bcm54xx_phy_can_wakeup(phydev)) {
+		wol->supported = 0;
+		return;
+	}
+
+	bcm_phy_get_wol(phydev, wol);
+}
+
+static int bcm54xx_phy_set_wol(struct phy_device *phydev,
+			       struct ethtool_wolinfo *wol)
+{
+	int ret;
+
+	/* We cannot wake-up if we do not have a dedicated PHY interrupt line
+	 * or an out of band GPIO descriptor for wake-up. Returning -EOPNOTSUPP
+	 * allows the caller (MAC driver) to play through and offer its own
+	 * Wake-on-LAN scheme if available.
+	 */
+	if (!bcm54xx_phy_can_wakeup(phydev))
+		return -EOPNOTSUPP;
+
+	ret = bcm_phy_set_wol(phydev, wol);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 static int bcm54xx_phy_probe(struct phy_device *phydev)
 {
 	struct bcm54xx_phy_priv *priv;
+	struct gpio_desc *wakeup_gpio;
+	int ret = 0;
 
 	priv = devm_kzalloc(&phydev->mdio.dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
+	priv->wake_irq = -ENXIO;
+
 	phydev->priv = priv;
 
 	priv->stats = devm_kcalloc(&phydev->mdio.dev,
@@ -821,7 +917,28 @@ static int bcm54xx_phy_probe(struct phy_device *phydev)
 	if (IS_ERR(priv->ptp))
 		return PTR_ERR(priv->ptp);
 
-	return 0;
+	/* We cannot utilize the _optional variant here since we want to know
+	 * whether the GPIO descriptor exists or not to advertise Wake-on-LAN
+	 * support or not.
+	 */
+	wakeup_gpio = devm_gpiod_get(&phydev->mdio.dev, "wakeup", GPIOD_IN);
+	if (PTR_ERR(wakeup_gpio) == -EPROBE_DEFER)
+		return PTR_ERR(wakeup_gpio);
+
+	if (!IS_ERR(wakeup_gpio)) {
+		priv->wake_irq = gpiod_to_irq(wakeup_gpio);
+		ret = irq_set_irq_type(priv->wake_irq, IRQ_TYPE_LEVEL_LOW);
+		if (ret)
+			return ret;
+	}
+
+	/* If we do not have a main interrupt or a side-band wake-up interrupt,
+	 * then the device cannot be marked as wake-up capable.
+	 */
+	if (!bcm54xx_phy_can_wakeup(phydev))
+		return 0;
+
+	return device_init_wakeup(&phydev->mdio.dev, true);
 }
 
 static void bcm54xx_get_stats(struct phy_device *phydev,
@@ -894,6 +1011,7 @@ static struct phy_driver broadcom_drivers[] = {
 	.phy_id_mask	= 0xfffffff0,
 	.name		= "Broadcom BCM54210E",
 	/* PHY_GBIT_FEATURES */
+	.flags		= PHY_ALWAYS_CALL_SUSPEND,
 	.get_sset_count	= bcm_phy_get_sset_count,
 	.get_strings	= bcm_phy_get_strings,
 	.get_stats	= bcm54xx_get_stats,
@@ -904,6 +1022,8 @@ static struct phy_driver broadcom_drivers[] = {
 	.link_change_notify	= bcm54xx_link_change_notify,
 	.suspend	= bcm54xx_suspend,
 	.resume		= bcm54xx_resume,
+	.get_wol	= bcm54xx_phy_get_wol,
+	.set_wol	= bcm54xx_phy_set_wol,
 }, {
 	.phy_id		= PHY_ID_BCM5461,
 	.phy_id_mask	= 0xfffffff0,