net: dsa: microchip: lan937x: add interrupt support for port phy link

This patch enables the interrupts for internal phy link detection for
LAN937x. The interrupt enable bits are active low. There is global
interrupt mask for each port. And each port has the individual interrupt
mask for TAS. QCI, SGMII, PTP, PHY and ACL.
The first level of interrupt domain is registered for global port
interrupt and second level of interrupt domain for the individual port
interrupts. The phy interrupt is enabled in the lan937x_mdio_register
function. Interrupt from which port is raised will be detected based on
the interrupt host data.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 360 insertions, 4 deletions

diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
index 0466c4d0b10c..4867aa62dd4c 100644
--- a/drivers/net/dsa/microchip/lan937x_main.c
+++ b/drivers/net/dsa/microchip/lan937x_main.c
@@ -10,6 +10,8 @@
 #include <linux/of_mdio.h>
 #include <linux/if_bridge.h>
 #include <linux/if_vlan.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/math.h>
 #include <net/dsa.h>
 #include <net/switchdev.h>
@@ -18,6 +20,8 @@
 #include "ksz_common.h"
 #include "lan937x.h"
 
+#define LAN937x_PNIRQS 6
+
 static int lan937x_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
 {
 	return regmap_update_bits(dev->regmap[0], addr, bits, set ? bits : 0);
@@ -165,6 +169,45 @@ static int lan937x_sw_mdio_write(struct mii_bus *bus, int addr, int regnum,
 	return lan937x_internal_phy_write(dev, addr, regnum, val);
 }
 
+static int lan937x_irq_phy_setup(struct ksz_device *dev)
+{
+	struct dsa_switch *ds = dev->ds;
+	int phy, err_phy;
+	int irq;
+	int ret;
+
+	for (phy = 0; phy < KSZ_MAX_NUM_PORTS; phy++) {
+		if (BIT(phy) & ds->phys_mii_mask) {
+			irq = irq_find_mapping(dev->ports[phy].pirq.domain,
+					       PORT_SRC_PHY_INT);
+			if (irq < 0) {
+				ret = irq;
+				goto out;
+			}
+			ds->slave_mii_bus->irq[phy] = irq;
+		}
+	}
+	return 0;
+out:
+	err_phy = phy;
+
+	for (phy = 0; phy < err_phy; phy++)
+		if (BIT(phy) & ds->phys_mii_mask)
+			irq_dispose_mapping(ds->slave_mii_bus->irq[phy]);
+
+	return ret;
+}
+
+static void lan937x_irq_phy_free(struct ksz_device *dev)
+{
+	struct dsa_switch *ds = dev->ds;
+	int phy;
+
+	for (phy = 0; phy < KSZ_MAX_NUM_PORTS; phy++)
+		if (BIT(phy) & ds->phys_mii_mask)
+			irq_dispose_mapping(ds->slave_mii_bus->irq[phy]);
+}
+
 static int lan937x_mdio_register(struct ksz_device *dev)
 {
 	struct dsa_switch *ds = dev->ds;
@@ -194,10 +237,15 @@ static int lan937x_mdio_register(struct ksz_device *dev)
 
 	ds->slave_mii_bus = bus;
 
+	ret = lan937x_irq_phy_setup(dev);
+	if (ret)
+		return ret;
+
 	ret = devm_of_mdiobus_register(ds->dev, bus, mdio_np);
 	if (ret) {
 		dev_err(ds->dev, "unable to register MDIO bus %s\n",
 			bus->id);
+		lan937x_irq_phy_free(dev);
 	}
 
 	of_node_put(mdio_np);
@@ -387,9 +435,289 @@ void lan937x_setup_rgmii_delay(struct ksz_device *dev, int port)
 	}
 }
 
+int lan937x_switch_init(struct ksz_device *dev)
+{
+	dev->port_mask = (1 << dev->info->port_cnt) - 1;
+
+	return 0;
+}
+
+static void lan937x_girq_mask(struct irq_data *d)
+{
+	struct ksz_device *dev = irq_data_get_irq_chip_data(d);
+	unsigned int n = d->hwirq;
+
+	dev->girq.masked |= (1 << n);
+}
+
+static void lan937x_girq_unmask(struct irq_data *d)
+{
+	struct ksz_device *dev = irq_data_get_irq_chip_data(d);
+	unsigned int n = d->hwirq;
+
+	dev->girq.masked &= ~(1 << n);
+}
+
+static void lan937x_girq_bus_lock(struct irq_data *d)
+{
+	struct ksz_device *dev = irq_data_get_irq_chip_data(d);
+
+	mutex_lock(&dev->lock_irq);
+}
+
+static void lan937x_girq_bus_sync_unlock(struct irq_data *d)
+{
+	struct ksz_device *dev = irq_data_get_irq_chip_data(d);
+	int ret;
+
+	ret = ksz_write32(dev, REG_SW_PORT_INT_MASK__4, dev->girq.masked);
+	if (ret)
+		dev_err(dev->dev, "failed to change IRQ mask\n");
+
+	mutex_unlock(&dev->lock_irq);
+}
+
+static const struct irq_chip lan937x_girq_chip = {
+	.name			= "lan937x-global",
+	.irq_mask		= lan937x_girq_mask,
+	.irq_unmask		= lan937x_girq_unmask,
+	.irq_bus_lock		= lan937x_girq_bus_lock,
+	.irq_bus_sync_unlock	= lan937x_girq_bus_sync_unlock,
+};
+
+static int lan937x_girq_domain_map(struct irq_domain *d,
+				   unsigned int irq, irq_hw_number_t hwirq)
+{
+	struct ksz_device *dev = d->host_data;
+
+	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_and_handler(irq, &dev->girq.chip, handle_level_irq);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops lan937x_girq_domain_ops = {
+	.map	= lan937x_girq_domain_map,
+	.xlate	= irq_domain_xlate_twocell,
+};
+
+static void lan937x_girq_free(struct ksz_device *dev)
+{
+	int irq, virq;
+
+	free_irq(dev->irq, dev);
+
+	for (irq = 0; irq < dev->girq.nirqs; irq++) {
+		virq = irq_find_mapping(dev->girq.domain, irq);
+		irq_dispose_mapping(virq);
+	}
+
+	irq_domain_remove(dev->girq.domain);
+}
+
+static irqreturn_t lan937x_girq_thread_fn(int irq, void *dev_id)
+{
+	struct ksz_device *dev = dev_id;
+	unsigned int nhandled = 0;
+	unsigned int sub_irq;
+	unsigned int n;
+	u32 data;
+	int ret;
+
+	/* Read global interrupt status register */
+	ret = ksz_read32(dev, REG_SW_PORT_INT_STATUS__4, &data);
+	if (ret)
+		goto out;
+
+	for (n = 0; n < dev->girq.nirqs; ++n) {
+		if (data & (1 << n)) {
+			sub_irq = irq_find_mapping(dev->girq.domain, n);
+			handle_nested_irq(sub_irq);
+			++nhandled;
+		}
+	}
+out:
+	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
+}
+
+static int lan937x_girq_setup(struct ksz_device *dev)
+{
+	int ret, irq;
+
+	dev->girq.nirqs = dev->info->port_cnt;
+	dev->girq.domain = irq_domain_add_simple(NULL, dev->girq.nirqs, 0,
+						 &lan937x_girq_domain_ops, dev);
+	if (!dev->girq.domain)
+		return -ENOMEM;
+
+	for (irq = 0; irq < dev->girq.nirqs; irq++)
+		irq_create_mapping(dev->girq.domain, irq);
+
+	dev->girq.chip = lan937x_girq_chip;
+	dev->girq.masked = ~0;
+
+	ret = request_threaded_irq(dev->irq, NULL, lan937x_girq_thread_fn,
+				   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
+				   dev_name(dev->dev), dev);
+	if (ret)
+		goto out;
+
+	return 0;
+
+out:
+	lan937x_girq_free(dev);
+
+	return ret;
+}
+
+static void lan937x_pirq_mask(struct irq_data *d)
+{
+	struct ksz_port *port = irq_data_get_irq_chip_data(d);
+	unsigned int n = d->hwirq;
+
+	port->pirq.masked |= (1 << n);
+}
+
+static void lan937x_pirq_unmask(struct irq_data *d)
+{
+	struct ksz_port *port = irq_data_get_irq_chip_data(d);
+	unsigned int n = d->hwirq;
+
+	port->pirq.masked &= ~(1 << n);
+}
+
+static void lan937x_pirq_bus_lock(struct irq_data *d)
+{
+	struct ksz_port *port = irq_data_get_irq_chip_data(d);
+	struct ksz_device *dev = port->ksz_dev;
+
+	mutex_lock(&dev->lock_irq);
+}
+
+static void lan937x_pirq_bus_sync_unlock(struct irq_data *d)
+{
+	struct ksz_port *port = irq_data_get_irq_chip_data(d);
+	struct ksz_device *dev = port->ksz_dev;
+
+	ksz_pwrite8(dev, port->num, REG_PORT_INT_MASK, port->pirq.masked);
+	mutex_unlock(&dev->lock_irq);
+}
+
+static const struct irq_chip lan937x_pirq_chip = {
+	.name			= "lan937x-port",
+	.irq_mask		= lan937x_pirq_mask,
+	.irq_unmask		= lan937x_pirq_unmask,
+	.irq_bus_lock		= lan937x_pirq_bus_lock,
+	.irq_bus_sync_unlock	= lan937x_pirq_bus_sync_unlock,
+};
+
+static int lan937x_pirq_domain_map(struct irq_domain *d, unsigned int irq,
+				   irq_hw_number_t hwirq)
+{
+	struct ksz_port *port = d->host_data;
+
+	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_and_handler(irq, &port->pirq.chip, handle_level_irq);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops lan937x_pirq_domain_ops = {
+	.map	= lan937x_pirq_domain_map,
+	.xlate	= irq_domain_xlate_twocell,
+};
+
+static void lan937x_pirq_free(struct ksz_device *dev, u8 p)
+{
+	struct ksz_port *port = &dev->ports[p];
+	int irq, virq;
+	int irq_num;
+
+	irq_num = irq_find_mapping(dev->girq.domain, p);
+	if (irq_num < 0)
+		return;
+
+	free_irq(irq_num, port);
+
+	for (irq = 0; irq < port->pirq.nirqs; irq++) {
+		virq = irq_find_mapping(port->pirq.domain, irq);
+		irq_dispose_mapping(virq);
+	}
+
+	irq_domain_remove(port->pirq.domain);
+}
+
+static irqreturn_t lan937x_pirq_thread_fn(int irq, void *dev_id)
+{
+	struct ksz_port *port = dev_id;
+	unsigned int nhandled = 0;
+	struct ksz_device *dev;
+	unsigned int sub_irq;
+	unsigned int n;
+	u8 data;
+
+	dev = port->ksz_dev;
+
+	/* Read port interrupt status register */
+	ksz_pread8(dev, port->num, REG_PORT_INT_STATUS, &data);
+
+	for (n = 0; n < port->pirq.nirqs; ++n) {
+		if (data & (1 << n)) {
+			sub_irq = irq_find_mapping(port->pirq.domain, n);
+			handle_nested_irq(sub_irq);
+			++nhandled;
+		}
+	}
+
+	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
+}
+
+static int lan937x_pirq_setup(struct ksz_device *dev, u8 p)
+{
+	struct ksz_port *port = &dev->ports[p];
+	int ret, irq;
+	int irq_num;
+
+	port->pirq.nirqs = LAN937x_PNIRQS;
+	port->pirq.domain = irq_domain_add_simple(dev->dev->of_node,
+						  port->pirq.nirqs, 0,
+						  &lan937x_pirq_domain_ops,
+						  port);
+	if (!port->pirq.domain)
+		return -ENOMEM;
+
+	for (irq = 0; irq < port->pirq.nirqs; irq++)
+		irq_create_mapping(port->pirq.domain, irq);
+
+	port->pirq.chip = lan937x_pirq_chip;
+	port->pirq.masked = ~0;
+
+	irq_num = irq_find_mapping(dev->girq.domain, p);
+	if (irq_num < 0)
+		return irq_num;
+
+	snprintf(port->pirq.name, sizeof(port->pirq.name), "port_irq-%d", p);
+
+	ret = request_threaded_irq(irq_num, NULL, lan937x_pirq_thread_fn,
+				   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
+				   port->pirq.name, port);
+	if (ret)
+		goto out;
+
+	return 0;
+
+out:
+	lan937x_pirq_free(dev, p);
+
+	return ret;
+}
+
 int lan937x_setup(struct dsa_switch *ds)
 {
 	struct ksz_device *dev = ds->priv;
+	struct dsa_port *dp;
 	int ret;
 
 	/* enable Indirect Access from SPI to the VPHY registers */
@@ -399,10 +727,22 @@ int lan937x_setup(struct dsa_switch *ds)
 		return ret;
 	}
 
+	if (dev->irq > 0) {
+		ret = lan937x_girq_setup(dev);
+		if (ret)
+			return ret;
+
+		dsa_switch_for_each_user_port(dp, dev->ds) {
+			ret = lan937x_pirq_setup(dev, dp->index);
+			if (ret)
+				goto out_girq;
+		}
+	}
+
 	ret = lan937x_mdio_register(dev);
 	if (ret < 0) {
 		dev_err(dev->dev, "failed to register the mdio");
-		return ret;
+		goto out_pirq;
 	}
 
 	/* The VLAN aware is a global setting. Mixed vlan
@@ -428,13 +768,29 @@ int lan937x_setup(struct dsa_switch *ds)
 		    (SW_CLK125_ENB | SW_CLK25_ENB), true);
 
 	return 0;
+
+out_pirq:
+	if (dev->irq > 0)
+		dsa_switch_for_each_user_port(dp, dev->ds)
+			lan937x_pirq_free(dev, dp->index);
+out_girq:
+	if (dev->irq > 0)
+		lan937x_girq_free(dev);
+
+	return ret;
 }
 
-int lan937x_switch_init(struct ksz_device *dev)
+void lan937x_teardown(struct dsa_switch *ds)
 {
-	dev->port_mask = (1 << dev->info->port_cnt) - 1;
+	struct ksz_device *dev = ds->priv;
+	struct dsa_port *dp;
 
-	return 0;
+	if (dev->irq > 0) {
+		dsa_switch_for_each_user_port(dp, dev->ds)
+			lan937x_pirq_free(dev, dp->index);
+
+		lan937x_girq_free(dev);
+	}
 }
 
 void lan937x_switch_exit(struct ksz_device *dev)