lan78xx: Use irq_domain for phy interrupt from USB Int. EP

To utilize phylib with interrupt fully than handling some of phy stuff in the MAC driver,
create irq_domain for USB interrupt EP of phy interrupt and
pass the irq number to phy_connect_direct() instead of PHY_IGNORE_INTERRUPT.

Idea comes from drivers/gpio/gpio-dl2.c
Signed-off-by: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/lan78xx.c

@@ -30,13 +30,17 @@
 #include <linux/ipv6.h>
 #include <linux/mdio.h>
 #include <net/ip6_checksum.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/microchipphy.h>
 #include "lan78xx.h"
 
 #define DRIVER_AUTHOR	"WOOJUNG HUH <woojung.huh@microchip.com>"
 #define DRIVER_DESC	"LAN78XX USB 3.0 Gigabit Ethernet Devices"
 #define DRIVER_NAME	"lan78xx"
-#define DRIVER_VERSION	"1.0.4"
+#define DRIVER_VERSION	"1.0.5"
 
 #define TX_TIMEOUT_JIFFIES		(5 * HZ)
 #define THROTTLE_JIFFIES		(HZ / 8)
@@ -89,6 +93,38 @@
 /* statistic update interval (mSec) */
 #define STAT_UPDATE_TIMER		(1 * 1000)
 
+/* defines interrupts from interrupt EP */
+#define MAX_INT_EP			(32)
+#define INT_EP_INTEP			(31)
+#define INT_EP_OTP_WR_DONE		(28)
+#define INT_EP_EEE_TX_LPI_START		(26)
+#define INT_EP_EEE_TX_LPI_STOP		(25)
+#define INT_EP_EEE_RX_LPI		(24)
+#define INT_EP_MAC_RESET_TIMEOUT	(23)
+#define INT_EP_RDFO			(22)
+#define INT_EP_TXE			(21)
+#define INT_EP_USB_STATUS		(20)
+#define INT_EP_TX_DIS			(19)
+#define INT_EP_RX_DIS			(18)
+#define INT_EP_PHY			(17)
+#define INT_EP_DP			(16)
+#define INT_EP_MAC_ERR			(15)
+#define INT_EP_TDFU			(14)
+#define INT_EP_TDFO			(13)
+#define INT_EP_UTX			(12)
+#define INT_EP_GPIO_11			(11)
+#define INT_EP_GPIO_10			(10)
+#define INT_EP_GPIO_9			(9)
+#define INT_EP_GPIO_8			(8)
+#define INT_EP_GPIO_7			(7)
+#define INT_EP_GPIO_6			(6)
+#define INT_EP_GPIO_5			(5)
+#define INT_EP_GPIO_4			(4)
+#define INT_EP_GPIO_3			(3)
+#define INT_EP_GPIO_2			(2)
+#define INT_EP_GPIO_1			(1)
+#define INT_EP_GPIO_0			(0)
+
 static const char lan78xx_gstrings[][ETH_GSTRING_LEN] = {
 	"RX FCS Errors",
 	"RX Alignment Errors",
@@ -296,6 +332,15 @@ struct statstage {
 	struct lan78xx_statstage64	curr_stat;
 };
 
+struct irq_domain_data {
+	struct irq_domain	*irqdomain;
+	unsigned int		phyirq;
+	struct irq_chip		*irqchip;
+	irq_flow_handler_t	irq_handler;
+	u32			irqenable;
+	struct mutex		irq_lock;		/* for irq bus access */
+};
+
 struct lan78xx_net {
 	struct net_device	*net;
 	struct usb_device	*udev;
@@ -351,6 +396,8 @@ struct lan78xx_net {
 
 	int			delta;
 	struct statstage	stats;
+
+	struct irq_domain_data	domain_data;
 };
 
 /* use ethtool to change the level for any given device */
@@ -1096,11 +1143,6 @@ static int lan78xx_link_reset(struct lan78xx_net *dev)
 	int ladv, radv, ret;
 	u32 buf;
 
-	/* clear PHY interrupt status */
-	ret = phy_read(phydev, LAN88XX_INT_STS);
-	if (unlikely(ret < 0))
-		return -EIO;
-
 	/* clear LAN78xx interrupt status */
 	ret = lan78xx_write_reg(dev, INT_STS, INT_STS_PHY_INT_);
 	if (unlikely(ret < 0))
@@ -1120,16 +1162,12 @@ static int lan78xx_link_reset(struct lan78xx_net *dev)
 		if (unlikely(ret < 0))
 			return -EIO;
 
-		phy_mac_interrupt(phydev, 0);
-
 		del_timer(&dev->stat_monitor);
 	} else if (phydev->link && !dev->link_on) {
 		dev->link_on = true;
 
 		phy_ethtool_ksettings_get(phydev, &ecmd);
 
-		ret = phy_read(phydev, LAN88XX_INT_STS);
-
 		if (dev->udev->speed == USB_SPEED_SUPER) {
 			if (ecmd.base.speed == 1000) {
 				/* disable U2 */
@@ -1163,7 +1201,6 @@ static int lan78xx_link_reset(struct lan78xx_net *dev)
 
 		ret = lan78xx_update_flowcontrol(dev, ecmd.base.duplex, ladv,
 						 radv);
-		phy_mac_interrupt(phydev, 1);
 
 		if (!timer_pending(&dev->stat_monitor)) {
 			dev->delta = 1;
@@ -1203,6 +1240,9 @@ static void lan78xx_status(struct lan78xx_net *dev, struct urb *urb)
 	if (intdata & INT_ENP_PHY_INT) {
 		netif_dbg(dev, link, dev->net, "PHY INTR: 0x%08x\n", intdata);
 		lan78xx_defer_kevent(dev, EVENT_LINK_RESET);
+
+		if (dev->domain_data.phyirq > 0)
+			generic_handle_irq(dev->domain_data.phyirq);
 	} else
 		netdev_warn(dev->net,
 			    "unexpected interrupt: 0x%08x\n", intdata);
@@ -1844,6 +1884,127 @@ static void lan78xx_link_status_change(struct net_device *net)
 	}
 }
 
+static int irq_map(struct irq_domain *d, unsigned int irq,
+		   irq_hw_number_t hwirq)
+{
+	struct irq_domain_data *data = d->host_data;
+
+	irq_set_chip_data(irq, data);
+	irq_set_chip_and_handler(irq, data->irqchip, data->irq_handler);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static void irq_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+}
+
+static const struct irq_domain_ops chip_domain_ops = {
+	.map	= irq_map,
+	.unmap	= irq_unmap,
+};
+
+static void lan78xx_irq_mask(struct irq_data *irqd)
+{
+	struct irq_domain_data *data = irq_data_get_irq_chip_data(irqd);
+
+	data->irqenable &= ~BIT(irqd_to_hwirq(irqd));
+}
+
+static void lan78xx_irq_unmask(struct irq_data *irqd)
+{
+	struct irq_domain_data *data = irq_data_get_irq_chip_data(irqd);
+
+	data->irqenable |= BIT(irqd_to_hwirq(irqd));
+}
+
+static void lan78xx_irq_bus_lock(struct irq_data *irqd)
+{
+	struct irq_domain_data *data = irq_data_get_irq_chip_data(irqd);
+
+	mutex_lock(&data->irq_lock);
+}
+
+static void lan78xx_irq_bus_sync_unlock(struct irq_data *irqd)
+{
+	struct irq_domain_data *data = irq_data_get_irq_chip_data(irqd);
+	struct lan78xx_net *dev =
+			container_of(data, struct lan78xx_net, domain_data);
+	u32 buf;
+	int ret;
+
+	/* call register access here because irq_bus_lock & irq_bus_sync_unlock
+	 * are only two callbacks executed in non-atomic contex.
+	 */
+	ret = lan78xx_read_reg(dev, INT_EP_CTL, &buf);
+	if (buf != data->irqenable)
+		ret = lan78xx_write_reg(dev, INT_EP_CTL, data->irqenable);
+
+	mutex_unlock(&data->irq_lock);
+}
+
+static struct irq_chip lan78xx_irqchip = {
+	.name			= "lan78xx-irqs",
+	.irq_mask		= lan78xx_irq_mask,
+	.irq_unmask		= lan78xx_irq_unmask,
+	.irq_bus_lock		= lan78xx_irq_bus_lock,
+	.irq_bus_sync_unlock	= lan78xx_irq_bus_sync_unlock,
+};
+
+static int lan78xx_setup_irq_domain(struct lan78xx_net *dev)
+{
+	struct device_node *of_node;
+	struct irq_domain *irqdomain;
+	unsigned int irqmap = 0;
+	u32 buf;
+	int ret = 0;
+
+	of_node = dev->udev->dev.parent->of_node;
+
+	mutex_init(&dev->domain_data.irq_lock);
+
+	lan78xx_read_reg(dev, INT_EP_CTL, &buf);
+	dev->domain_data.irqenable = buf;
+
+	dev->domain_data.irqchip = &lan78xx_irqchip;
+	dev->domain_data.irq_handler = handle_simple_irq;
+
+	irqdomain = irq_domain_add_simple(of_node, MAX_INT_EP, 0,
+					  &chip_domain_ops, &dev->domain_data);
+	if (irqdomain) {
+		/* create mapping for PHY interrupt */
+		irqmap = irq_create_mapping(irqdomain, INT_EP_PHY);
+		if (!irqmap) {
+			irq_domain_remove(irqdomain);
+
+			irqdomain = NULL;
+			ret = -EINVAL;
+		}
+	} else {
+		ret = -EINVAL;
+	}
+
+	dev->domain_data.irqdomain = irqdomain;
+	dev->domain_data.phyirq = irqmap;
+
+	return ret;
+}
+
+static void lan78xx_remove_irq_domain(struct lan78xx_net *dev)
+{
+	if (dev->domain_data.phyirq > 0) {
+		irq_dispose_mapping(dev->domain_data.phyirq);
+
+		if (dev->domain_data.irqdomain)
+			irq_domain_remove(dev->domain_data.irqdomain);
+	}
+	dev->domain_data.phyirq = 0;
+	dev->domain_data.irqdomain = NULL;
+}
+
 static int lan78xx_phy_init(struct lan78xx_net *dev)
 {
 	int ret;
@@ -1856,15 +2017,12 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
 		return -EIO;
 	}
 
-	/* Enable PHY interrupts.
-	 * We handle our own interrupt
-	 */
-	ret = phy_read(phydev, LAN88XX_INT_STS);
-	ret = phy_write(phydev, LAN88XX_INT_MASK,
-			LAN88XX_INT_MASK_MDINTPIN_EN_ |
-			LAN88XX_INT_MASK_LINK_CHANGE_);
-
-	phydev->irq = PHY_IGNORE_INTERRUPT;
+	/* if phyirq is not set, use polling mode in phylib */
+	if (dev->domain_data.phyirq > 0)
+		phydev->irq = dev->domain_data.phyirq;
+	else
+		phydev->irq = 0;
+	netdev_dbg(dev->net, "phydev->irq = %d\n", phydev->irq);
 
 	ret = phy_connect_direct(dev->net, phydev,
 				 lan78xx_link_status_change,
@@ -2255,11 +2413,6 @@ static int lan78xx_reset(struct lan78xx_net *dev)
 	buf |= MAC_CR_AUTO_DUPLEX_ | MAC_CR_AUTO_SPEED_;
 	ret = lan78xx_write_reg(dev, MAC_CR, buf);
 
-	/* enable PHY interrupts */
-	ret = lan78xx_read_reg(dev, INT_EP_CTL, &buf);
-	buf |= INT_ENP_PHY_INT;
-	ret = lan78xx_write_reg(dev, INT_EP_CTL, buf);
-
 	ret = lan78xx_read_reg(dev, MAC_TX, &buf);
 	buf |= MAC_TX_TXEN_;
 	ret = lan78xx_write_reg(dev, MAC_TX, buf);
@@ -2668,6 +2821,14 @@ static int lan78xx_bind(struct lan78xx_net *dev, struct usb_interface *intf)
 
 	dev->net->hw_features = dev->net->features;
 
+	ret = lan78xx_setup_irq_domain(dev);
+	if (ret < 0) {
+		netdev_warn(dev->net,
+			    "lan78xx_setup_irq_domain() failed : %d", ret);
+		kfree(pdata);
+		return ret;
+	}
+
 	/* Init all registers */
 	ret = lan78xx_reset(dev);
 
@@ -2684,6 +2845,8 @@ static void lan78xx_unbind(struct lan78xx_net *dev, struct usb_interface *intf)
 {
 	struct lan78xx_priv *pdata = (struct lan78xx_priv *)(dev->data[0]);
 
+	lan78xx_remove_irq_domain(dev);
+
 	lan78xx_remove_mdio(dev);
 
 	if (pdata) {