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From:   Arun Ramadoss <arun.ramadoss@microchip.com>
To:     <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>
CC:     Woojung Huh <woojung.huh@microchip.com>,
        <UNGLinuxDriver@microchip.com>, Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "Russell King" <linux@armlinux.org.uk>,
        Tristram Ha <Tristram.Ha@microchip.com>
Subject: [RFC Patch net-next v3 3/3] net: dsa: microchip: lan937x: add interrupt support for port phy link
Date:   Tue, 30 Aug 2022 16:23:03 +0530
Message-ID: <20220830105303.22067-4-arun.ramadoss@microchip.com>
In-Reply-To: <20220830105303.22067-1-arun.ramadoss@microchip.com>
References: <20220830105303.22067-1-arun.ramadoss@microchip.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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Precedence: bulk

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>
---
 drivers/net/dsa/microchip/ksz_common.h   |  13 +
 drivers/net/dsa/microchip/ksz_spi.c      |   2 +
 drivers/net/dsa/microchip/lan937x_main.c | 332 ++++++++++++++++++++++-
 drivers/net/dsa/microchip/lan937x_reg.h  |  12 +
 4 files changed, 353 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index c675a58ef298..991c110a9cd8 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -13,6 +13,7 @@
 #include <linux/phy.h>
 #include <linux/regmap.h>
 #include <net/dsa.h>
+#include <linux/irq.h>
 
 #define KSZ_MAX_NUM_PORTS 8
 
@@ -65,6 +66,14 @@ struct ksz_chip_data {
 	bool internal_phy[KSZ_MAX_NUM_PORTS];
 };
 
+struct ksz_irq {
+	u16 masked;
+	struct irq_chip chip;
+	struct irq_domain *domain;
+	int nirqs;
+	char name[16];
+};
+
 struct ksz_port {
 	bool remove_tag;		/* Remove Tag flag set, for ksz8795 only */
 	bool learning;
@@ -85,6 +94,7 @@ struct ksz_port {
 	u32 rgmii_tx_val;
 	u32 rgmii_rx_val;
 	struct ksz_device *ksz_dev;
+	struct ksz_irq irq;
 	u8 num;
 };
 
@@ -103,6 +113,7 @@ struct ksz_device {
 	struct regmap *regmap[3];
 
 	void *priv;
+	int irq;
 
 	struct gpio_desc *reset_gpio;	/* Optional reset GPIO */
 
@@ -124,6 +135,8 @@ struct ksz_device {
 	u16 mirror_tx;
 	u32 features;			/* chip specific features */
 	u16 port_mask;
+	struct mutex lock_irq;		/* IRQ Access */
+	struct ksz_irq girq;
 };
 
 /* List of supported models */
diff --git a/drivers/net/dsa/microchip/ksz_spi.c b/drivers/net/dsa/microchip/ksz_spi.c
index 05bd089795f8..7ba897b6f950 100644
--- a/drivers/net/dsa/microchip/ksz_spi.c
+++ b/drivers/net/dsa/microchip/ksz_spi.c
@@ -85,6 +85,8 @@ static int ksz_spi_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	dev->irq = spi->irq;
+
 	ret = ksz_switch_register(dev);
 
 	/* Main DSA driver may not be started yet. */
diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
index daedd2bf20c1..3108f8b8c6fc 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);
@@ -171,6 +175,7 @@ static int lan937x_mdio_register(struct ksz_device *dev)
 	struct device_node *mdio_np;
 	struct mii_bus *bus;
 	int ret;
+	int p;
 
 	mdio_np = of_get_child_by_name(dev->dev->of_node, "mdio");
 	if (!mdio_np) {
@@ -194,6 +199,16 @@ static int lan937x_mdio_register(struct ksz_device *dev)
 
 	ds->slave_mii_bus = bus;
 
+	for (p = 0; p < KSZ_MAX_NUM_PORTS; p++) {
+		if (BIT(p) & ds->phys_mii_mask) {
+			unsigned int irq;
+
+			irq = irq_find_mapping(dev->ports[p].irq.domain,
+					       PORT_SRC_PHY_INT);
+			ds->slave_mii_bus->irq[p] = irq;
+		}
+	}
+
 	ret = devm_of_mdiobus_register(ds->dev, bus, mdio_np);
 	if (ret) {
 		dev_err(ds->dev, "unable to register MDIO bus %s\n",
@@ -383,9 +398,287 @@ 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;
+
+	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;
+
+	ret = ksz_read32(dev, REG_SW_INT_STATUS__4, &data);
+	if (ret)
+		goto out;
+
+	if (data & POR_READY_INT) {
+		ret = ksz_write32(dev, REG_SW_INT_STATUS__4, POR_READY_INT);
+		if (ret)
+			goto out;
+	}
+
+	/* 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->irq.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->irq.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->irq.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->irq.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_port *port, u8 p)
+{
+	int irq, virq;
+
+	for (irq = 0; irq < port->irq.nirqs; irq++) {
+		virq = irq_find_mapping(port->irq.domain, irq);
+		irq_dispose_mapping(virq);
+	}
+
+	irq_domain_remove(port->irq.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 global interrupt status register */
+	ksz_pread8(dev, port->num, REG_PORT_INT_STATUS, &data);
+
+	for (n = 0; n < port->irq.nirqs; ++n) {
+		if (data & (1 << n)) {
+			sub_irq = irq_find_mapping(port->irq.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->irq.nirqs = LAN937x_PNIRQS;
+	port->irq.domain = irq_domain_add_simple(dev->dev->of_node,
+						 port->irq.nirqs, 0,
+						 &lan937x_pirq_domain_ops,
+						 port);
+	if (!port->irq.domain)
+		return -ENOMEM;
+
+	for (irq = 0; irq < port->irq.nirqs; irq++)
+		irq_create_mapping(port->irq.domain, irq);
+
+	port->irq.chip = lan937x_pirq_chip;
+	port->irq.masked = ~0;
+
+	irq_num = irq_find_mapping(dev->girq.domain, p);
+
+	snprintf(port->irq.name, sizeof(port->irq.name), "port_irq-%d", p);
+
+	ret = request_threaded_irq(irq_num, NULL, lan937x_pirq_thread_fn,
+				   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
+				   port->irq.name, port);
+	if (ret)
+		goto out;
+
+	return 0;
+
+out:
+	lan937x_pirq_free(port, 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 */
@@ -395,10 +688,22 @@ 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
@@ -424,18 +729,33 @@ int lan937x_setup(struct dsa_switch *ds)
 		    (SW_CLK125_ENB | SW_CLK25_ENB), true);
 
 	return 0;
-}
 
-int lan937x_switch_init(struct ksz_device *dev)
-{
-	dev->port_mask = (1 << dev->info->port_cnt) - 1;
+out_pirq:
+	if (dev->irq > 0) {
+		dsa_switch_for_each_user_port(dp, dev->ds) {
+			lan937x_pirq_free(&dev->ports[dp->index], dp->index);
+		}
+	}
+out_girq:
+	if (dev->irq > 0)
+		lan937x_girq_free(dev);
 
-	return 0;
+	return ret;
 }
 
 void lan937x_switch_exit(struct ksz_device *dev)
 {
+	struct dsa_port *dp;
+
 	lan937x_reset_switch(dev);
+
+	if (dev->irq > 0) {
+		dsa_switch_for_each_user_port(dp, dev->ds) {
+			lan937x_pirq_free(&dev->ports[dp->index], dp->index);
+		}
+
+		lan937x_girq_free(dev);
+	}
 }
 
 MODULE_AUTHOR("Arun Ramadoss <arun.ramadoss@microchip.com>");
diff --git a/drivers/net/dsa/microchip/lan937x_reg.h b/drivers/net/dsa/microchip/lan937x_reg.h
index ba4adaddb3ec..a3c669d86e51 100644
--- a/drivers/net/dsa/microchip/lan937x_reg.h
+++ b/drivers/net/dsa/microchip/lan937x_reg.h
@@ -118,6 +118,18 @@
 /* Port Registers */
 
 /* 0 - Operation */
+#define REG_PORT_INT_STATUS		0x001B
+#define REG_PORT_INT_MASK		0x001F
+
+#define PORT_TAS_INT			BIT(5)
+#define PORT_QCI_INT			BIT(4)
+#define PORT_SGMII_INT			BIT(3)
+#define PORT_PTP_INT			BIT(2)
+#define PORT_PHY_INT			BIT(1)
+#define PORT_ACL_INT			BIT(0)
+
+#define PORT_SRC_PHY_INT		1
+
 #define REG_PORT_CTRL_0			0x0020
 
 #define PORT_MAC_LOOPBACK		BIT(7)
-- 
2.36.1