net: dsa: mv88e6xxx: Implement interrupt support.

The switch can have up to two interrupt controllers. One of these
contains the interrupts from the integrated PHYs, so is useful to
export. The Marvell PHY driver can then be used in interrupt mode,
rather than polling, speeding up PHY handling and reducing load on the
MDIO bus.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/global2.c

@@ -1,5 +1,6 @@
 /*
- * Marvell 88E6xxx Switch Global 2 Registers support (device address 0x1C)
+ * Marvell 88E6xxx Switch Global 2 Registers support (device address
+ * 0x1C)
  *
  * Copyright (c) 2008 Marvell Semiconductor
  *
@@ -11,6 +12,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/irqdomain.h>
 #include "mv88e6xxx.h"
 #include "global2.h"
 
@@ -417,6 +419,141 @@ int mv88e6xxx_g2_smi_phy_write(struct mv88e6xxx_chip *chip, int addr, int reg,
 	return mv88e6xxx_g2_smi_phy_cmd(chip, cmd);
 }
 
+static void mv88e6xxx_g2_irq_mask(struct irq_data *d)
+{
+	struct mv88e6xxx_chip *chip = irq_data_get_irq_chip_data(d);
+	unsigned int n = d->hwirq;
+
+	chip->g2_irq.masked |= (1 << n);
+}
+
+static void mv88e6xxx_g2_irq_unmask(struct irq_data *d)
+{
+	struct mv88e6xxx_chip *chip = irq_data_get_irq_chip_data(d);
+	unsigned int n = d->hwirq;
+
+	chip->g2_irq.masked &= ~(1 << n);
+}
+
+static irqreturn_t mv88e6xxx_g2_irq_thread_fn(int irq, void *dev_id)
+{
+	struct mv88e6xxx_chip *chip = dev_id;
+	unsigned int nhandled = 0;
+	unsigned int sub_irq;
+	unsigned int n;
+	int err;
+	u16 reg;
+
+	mutex_lock(&chip->reg_lock);
+	err = mv88e6xxx_g2_read(chip, GLOBAL2_INT_SOURCE, &reg);
+	mutex_unlock(&chip->reg_lock);
+	if (err)
+		goto out;
+
+	for (n = 0; n < 16; ++n) {
+		if (reg & (1 << n)) {
+			sub_irq = irq_find_mapping(chip->g2_irq.domain, n);
+			handle_nested_irq(sub_irq);
+			++nhandled;
+		}
+	}
+out:
+	return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
+}
+
+static void mv88e6xxx_g2_irq_bus_lock(struct irq_data *d)
+{
+	struct mv88e6xxx_chip *chip = irq_data_get_irq_chip_data(d);
+
+	mutex_lock(&chip->reg_lock);
+}
+
+static void mv88e6xxx_g2_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct mv88e6xxx_chip *chip = irq_data_get_irq_chip_data(d);
+
+	mv88e6xxx_g2_write(chip, GLOBAL2_INT_MASK, ~chip->g2_irq.masked);
+
+	mutex_unlock(&chip->reg_lock);
+}
+
+static struct irq_chip mv88e6xxx_g2_irq_chip = {
+	.name			= "mv88e6xxx-g2",
+	.irq_mask		= mv88e6xxx_g2_irq_mask,
+	.irq_unmask		= mv88e6xxx_g2_irq_unmask,
+	.irq_bus_lock		= mv88e6xxx_g2_irq_bus_lock,
+	.irq_bus_sync_unlock	= mv88e6xxx_g2_irq_bus_sync_unlock,
+};
+
+static int mv88e6xxx_g2_irq_domain_map(struct irq_domain *d,
+				       unsigned int irq,
+				       irq_hw_number_t hwirq)
+{
+	struct mv88e6xxx_chip *chip = d->host_data;
+
+	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_and_handler(irq, &chip->g2_irq.chip, handle_level_irq);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops mv88e6xxx_g2_irq_domain_ops = {
+	.map	= mv88e6xxx_g2_irq_domain_map,
+	.xlate	= irq_domain_xlate_twocell,
+};
+
+void mv88e6xxx_g2_irq_free(struct mv88e6xxx_chip *chip)
+{
+	int irq, virq;
+
+	for (irq = 0; irq < 16; irq++) {
+		virq = irq_find_mapping(chip->g2_irq.domain, irq);
+		irq_dispose_mapping(virq);
+	}
+
+	irq_domain_remove(chip->g2_irq.domain);
+}
+
+int mv88e6xxx_g2_irq_setup(struct mv88e6xxx_chip *chip)
+{
+	int device_irq;
+	int err, irq;
+
+	if (!chip->dev->of_node)
+		return -EINVAL;
+
+	chip->g2_irq.domain = irq_domain_add_simple(
+		chip->dev->of_node, 16, 0, &mv88e6xxx_g2_irq_domain_ops, chip);
+	if (!chip->g2_irq.domain)
+		return -ENOMEM;
+
+	for (irq = 0; irq < 16; irq++)
+		irq_create_mapping(chip->g2_irq.domain, irq);
+
+	chip->g2_irq.chip = mv88e6xxx_g2_irq_chip;
+	chip->g2_irq.masked = ~0;
+
+	device_irq = irq_find_mapping(chip->g1_irq.domain,
+				      GLOBAL_STATUS_IRQ_DEVICE);
+	if (device_irq < 0) {
+		err = device_irq;
+		goto out;
+	}
+
+	err = devm_request_threaded_irq(chip->dev, device_irq, NULL,
+					mv88e6xxx_g2_irq_thread_fn,
+					IRQF_ONESHOT, "mv88e6xxx-g1", chip);
+	if (err)
+		goto out;
+
+	return 0;
+out:
+	mv88e6xxx_g2_irq_free(chip);
+
+	return err;
+}
+
 int mv88e6xxx_g2_setup(struct mv88e6xxx_chip *chip)
 {
 	u16 reg;