kernel: backport MT7530 IRQ support

Support MT7530 PHY link change interrupts, and enable for MT7621.

For external MT7530, a GPIO IRQ line is required, which is
board-specific, so it should be added to each DTS. In case the
interrupt-controller property is missing, it will fall back to
polling mode.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>

2 files changed, 428 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.10/772-v5.14-net-dsa-mt7530-add-interrupt-support.patch b/target/linux/generic/backport-5.10/772-v5.14-net-dsa-mt7530-add-interrupt-support.patch
new file mode 100644
index 0000000000..9890015301
--- /dev/null
+++ b/target/linux/generic/backport-5.10/772-v5.14-net-dsa-mt7530-add-interrupt-support.patch
@@ -0,0 +1,425 @@
+From ba751e28d44255744a30190faad0ca09b455c44d Mon Sep 17 00:00:00 2001
+From: DENG Qingfang <dqfext@gmail.com>
+Date: Wed, 19 May 2021 11:32:00 +0800
+Subject: [PATCH] net: dsa: mt7530: add interrupt support
+
+Add support for MT7530 interrupt controller to handle internal PHYs.
+In order to assign an IRQ number to each PHY, the registration of MDIO bus
+is also done in this driver.
+
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
+Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/dsa/mt7530.c | 264 +++++++++++++++++++++++++++++++++++----
+ drivers/net/dsa/mt7530.h |  20 ++-
+ 2 files changed, 256 insertions(+), 28 deletions(-)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -10,6 +10,7 @@
+ #include <linux/mfd/syscon.h>
+ #include <linux/module.h>
+ #include <linux/netdevice.h>
++#include <linux/of_irq.h>
+ #include <linux/of_mdio.h>
+ #include <linux/of_net.h>
+ #include <linux/of_platform.h>
+@@ -602,18 +603,14 @@ mt7530_mib_reset(struct dsa_switch *ds)
+ 	mt7530_write(priv, MT7530_MIB_CCR, CCR_MIB_ACTIVATE);
+ }
+ 
+-static int mt7530_phy_read(struct dsa_switch *ds, int port, int regnum)
++static int mt7530_phy_read(struct mt7530_priv *priv, int port, int regnum)
+ {
+-	struct mt7530_priv *priv = ds->priv;
+-
+ 	return mdiobus_read_nested(priv->bus, port, regnum);
+ }
+ 
+-static int mt7530_phy_write(struct dsa_switch *ds, int port, int regnum,
++static int mt7530_phy_write(struct mt7530_priv *priv, int port, int regnum,
+ 			    u16 val)
+ {
+-	struct mt7530_priv *priv = ds->priv;
+-
+ 	return mdiobus_write_nested(priv->bus, port, regnum, val);
+ }
+ 
+@@ -791,9 +788,8 @@ out:
+ }
+ 
+ static int
+-mt7531_ind_phy_read(struct dsa_switch *ds, int port, int regnum)
++mt7531_ind_phy_read(struct mt7530_priv *priv, int port, int regnum)
+ {
+-	struct mt7530_priv *priv = ds->priv;
+ 	int devad;
+ 	int ret;
+ 
+@@ -809,10 +805,9 @@ mt7531_ind_phy_read(struct dsa_switch *d
+ }
+ 
+ static int
+-mt7531_ind_phy_write(struct dsa_switch *ds, int port, int regnum,
++mt7531_ind_phy_write(struct mt7530_priv *priv, int port, int regnum,
+ 		     u16 data)
+ {
+-	struct mt7530_priv *priv = ds->priv;
+ 	int devad;
+ 	int ret;
+ 
+@@ -828,6 +823,22 @@ mt7531_ind_phy_write(struct dsa_switch *
+ 	return ret;
+ }
+ 
++static int
++mt753x_phy_read(struct mii_bus *bus, int port, int regnum)
++{
++	struct mt7530_priv *priv = bus->priv;
++
++	return priv->info->phy_read(priv, port, regnum);
++}
++
++static int
++mt753x_phy_write(struct mii_bus *bus, int port, int regnum, u16 val)
++{
++	struct mt7530_priv *priv = bus->priv;
++
++	return priv->info->phy_write(priv, port, regnum, val);
++}
++
+ static void
+ mt7530_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+ 		   uint8_t *data)
+@@ -1824,6 +1835,210 @@ mt7530_setup_gpio(struct mt7530_priv *pr
+ 	return devm_gpiochip_add_data(dev, gc, priv);
+ }
+ 
++static irqreturn_t
++mt7530_irq_thread_fn(int irq, void *dev_id)
++{
++	struct mt7530_priv *priv = dev_id;
++	bool handled = false;
++	u32 val;
++	int p;
++
++	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
++	val = mt7530_mii_read(priv, MT7530_SYS_INT_STS);
++	mt7530_mii_write(priv, MT7530_SYS_INT_STS, val);
++	mutex_unlock(&priv->bus->mdio_lock);
++
++	for (p = 0; p < MT7530_NUM_PHYS; p++) {
++		if (BIT(p) & val) {
++			unsigned int irq;
++
++			irq = irq_find_mapping(priv->irq_domain, p);
++			handle_nested_irq(irq);
++			handled = true;
++		}
++	}
++
++	return IRQ_RETVAL(handled);
++}
++
++static void
++mt7530_irq_mask(struct irq_data *d)
++{
++	struct mt7530_priv *priv = irq_data_get_irq_chip_data(d);
++
++	priv->irq_enable &= ~BIT(d->hwirq);
++}
++
++static void
++mt7530_irq_unmask(struct irq_data *d)
++{
++	struct mt7530_priv *priv = irq_data_get_irq_chip_data(d);
++
++	priv->irq_enable |= BIT(d->hwirq);
++}
++
++static void
++mt7530_irq_bus_lock(struct irq_data *d)
++{
++	struct mt7530_priv *priv = irq_data_get_irq_chip_data(d);
++
++	mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
++}
++
++static void
++mt7530_irq_bus_sync_unlock(struct irq_data *d)
++{
++	struct mt7530_priv *priv = irq_data_get_irq_chip_data(d);
++
++	mt7530_mii_write(priv, MT7530_SYS_INT_EN, priv->irq_enable);
++	mutex_unlock(&priv->bus->mdio_lock);
++}
++
++static struct irq_chip mt7530_irq_chip = {
++	.name = KBUILD_MODNAME,
++	.irq_mask = mt7530_irq_mask,
++	.irq_unmask = mt7530_irq_unmask,
++	.irq_bus_lock = mt7530_irq_bus_lock,
++	.irq_bus_sync_unlock = mt7530_irq_bus_sync_unlock,
++};
++
++static int
++mt7530_irq_map(struct irq_domain *domain, unsigned int irq,
++	       irq_hw_number_t hwirq)
++{
++	irq_set_chip_data(irq, domain->host_data);
++	irq_set_chip_and_handler(irq, &mt7530_irq_chip, handle_simple_irq);
++	irq_set_nested_thread(irq, true);
++	irq_set_noprobe(irq);
++
++	return 0;
++}
++
++static const struct irq_domain_ops mt7530_irq_domain_ops = {
++	.map = mt7530_irq_map,
++	.xlate = irq_domain_xlate_onecell,
++};
++
++static void
++mt7530_setup_mdio_irq(struct mt7530_priv *priv)
++{
++	struct dsa_switch *ds = priv->ds;
++	int p;
++
++	for (p = 0; p < MT7530_NUM_PHYS; p++) {
++		if (BIT(p) & ds->phys_mii_mask) {
++			unsigned int irq;
++
++			irq = irq_create_mapping(priv->irq_domain, p);
++			ds->slave_mii_bus->irq[p] = irq;
++		}
++	}
++}
++
++static int
++mt7530_setup_irq(struct mt7530_priv *priv)
++{
++	struct device *dev = priv->dev;
++	struct device_node *np = dev->of_node;
++	int ret;
++
++	if (!of_property_read_bool(np, "interrupt-controller")) {
++		dev_info(dev, "no interrupt support\n");
++		return 0;
++	}
++
++	priv->irq = of_irq_get(np, 0);
++	if (priv->irq <= 0) {
++		dev_err(dev, "failed to get parent IRQ: %d\n", priv->irq);
++		return priv->irq ? : -EINVAL;
++	}
++
++	priv->irq_domain = irq_domain_add_linear(np, MT7530_NUM_PHYS,
++						 &mt7530_irq_domain_ops, priv);
++	if (!priv->irq_domain) {
++		dev_err(dev, "failed to create IRQ domain\n");
++		return -ENOMEM;
++	}
++
++	/* This register must be set for MT7530 to properly fire interrupts */
++	if (priv->id != ID_MT7531)
++		mt7530_set(priv, MT7530_TOP_SIG_CTRL, TOP_SIG_CTRL_NORMAL);
++
++	ret = request_threaded_irq(priv->irq, NULL, mt7530_irq_thread_fn,
++				   IRQF_ONESHOT, KBUILD_MODNAME, priv);
++	if (ret) {
++		irq_domain_remove(priv->irq_domain);
++		dev_err(dev, "failed to request IRQ: %d\n", ret);
++		return ret;
++	}
++
++	return 0;
++}
++
++static void
++mt7530_free_mdio_irq(struct mt7530_priv *priv)
++{
++	int p;
++
++	for (p = 0; p < MT7530_NUM_PHYS; p++) {
++		if (BIT(p) & priv->ds->phys_mii_mask) {
++			unsigned int irq;
++
++			irq = irq_find_mapping(priv->irq_domain, p);
++			irq_dispose_mapping(irq);
++		}
++	}
++}
++
++static void
++mt7530_free_irq_common(struct mt7530_priv *priv)
++{
++	free_irq(priv->irq, priv);
++	irq_domain_remove(priv->irq_domain);
++}
++
++static void
++mt7530_free_irq(struct mt7530_priv *priv)
++{
++	mt7530_free_mdio_irq(priv);
++	mt7530_free_irq_common(priv);
++}
++
++static int
++mt7530_setup_mdio(struct mt7530_priv *priv)
++{
++	struct dsa_switch *ds = priv->ds;
++	struct device *dev = priv->dev;
++	struct mii_bus *bus;
++	static int idx;
++	int ret;
++
++	bus = devm_mdiobus_alloc(dev);
++	if (!bus)
++		return -ENOMEM;
++
++	ds->slave_mii_bus = bus;
++	bus->priv = priv;
++	bus->name = KBUILD_MODNAME "-mii";
++	snprintf(bus->id, MII_BUS_ID_SIZE, KBUILD_MODNAME "-%d", idx++);
++	bus->read = mt753x_phy_read;
++	bus->write = mt753x_phy_write;
++	bus->parent = dev;
++	bus->phy_mask = ~ds->phys_mii_mask;
++
++	if (priv->irq)
++		mt7530_setup_mdio_irq(priv);
++
++	ret = devm_mdiobus_register(dev, bus);
++	if (ret) {
++		dev_err(dev, "failed to register MDIO bus: %d\n", ret);
++		if (priv->irq)
++			mt7530_free_mdio_irq(priv);
++	}
++
++	return ret;
++}
++
+ static int
+ mt7530_setup(struct dsa_switch *ds)
+ {
+@@ -2798,24 +3013,20 @@ static int
+ mt753x_setup(struct dsa_switch *ds)
+ {
+ 	struct mt7530_priv *priv = ds->priv;
++	int ret = priv->info->sw_setup(ds);
+ 
+-	return priv->info->sw_setup(ds);
+-}
+-
+-static int
+-mt753x_phy_read(struct dsa_switch *ds, int port, int regnum)
+-{
+-	struct mt7530_priv *priv = ds->priv;
++	if (ret)
++		return ret;
+ 
+-	return priv->info->phy_read(ds, port, regnum);
+-}
++	ret = mt7530_setup_irq(priv);
++	if (ret)
++		return ret;
+ 
+-static int
+-mt753x_phy_write(struct dsa_switch *ds, int port, int regnum, u16 val)
+-{
+-	struct mt7530_priv *priv = ds->priv;
++	ret = mt7530_setup_mdio(priv);
++	if (ret && priv->irq)
++		mt7530_free_irq_common(priv);
+ 
+-	return priv->info->phy_write(ds, port, regnum, val);
++	return ret;
+ }
+ 
+ static int mt753x_get_mac_eee(struct dsa_switch *ds, int port,
+@@ -2852,8 +3063,6 @@ static const struct dsa_switch_ops mt753
+ 	.get_tag_protocol	= mtk_get_tag_protocol,
+ 	.setup			= mt753x_setup,
+ 	.get_strings		= mt7530_get_strings,
+-	.phy_read		= mt753x_phy_read,
+-	.phy_write		= mt753x_phy_write,
+ 	.get_ethtool_stats	= mt7530_get_ethtool_stats,
+ 	.get_sset_count		= mt7530_get_sset_count,
+ 	.set_ageing_time	= mt7530_set_ageing_time,
+@@ -3036,6 +3245,9 @@ mt7530_remove(struct mdio_device *mdiode
+ 		dev_err(priv->dev, "Failed to disable io pwr: %d\n",
+ 			ret);
+ 
++	if (priv->irq)
++		mt7530_free_irq(priv);
++
+ 	dsa_unregister_switch(priv->ds);
+ 	mutex_destroy(&priv->reg_mutex);
+ }
+--- a/drivers/net/dsa/mt7530.h
++++ b/drivers/net/dsa/mt7530.h
+@@ -7,6 +7,7 @@
+ #define __MT7530_H
+ 
+ #define MT7530_NUM_PORTS		7
++#define MT7530_NUM_PHYS			5
+ #define MT7530_CPU_PORT			6
+ #define MT7530_NUM_FDB_RECORDS		2048
+ #define MT7530_ALL_MEMBERS		0xff
+@@ -401,6 +402,12 @@ enum mt7531_sgmii_force_duplex {
+ #define  SYS_CTRL_SW_RST		BIT(1)
+ #define  SYS_CTRL_REG_RST		BIT(0)
+ 
++/* Register for system interrupt */
++#define MT7530_SYS_INT_EN		0x7008
++
++/* Register for system interrupt status */
++#define MT7530_SYS_INT_STS		0x700c
++
+ /* Register for PHY Indirect Access Control */
+ #define MT7531_PHY_IAC			0x701C
+ #define  MT7531_PHY_ACS_ST		BIT(31)
+@@ -722,6 +729,8 @@ static const char *p5_intf_modes(unsigne
+ 	}
+ }
+ 
++struct mt7530_priv;
++
+ /* struct mt753x_info -	This is the main data structure for holding the specific
+  *			part for each supported device
+  * @sw_setup:		Holding the handler to a device initialization
+@@ -746,8 +755,8 @@ struct mt753x_info {
+ 	enum mt753x_id id;
+ 
+ 	int (*sw_setup)(struct dsa_switch *ds);
+-	int (*phy_read)(struct dsa_switch *ds, int port, int regnum);
+-	int (*phy_write)(struct dsa_switch *ds, int port, int regnum, u16 val);
++	int (*phy_read)(struct mt7530_priv *priv, int port, int regnum);
++	int (*phy_write)(struct mt7530_priv *priv, int port, int regnum, u16 val);
+ 	int (*pad_setup)(struct dsa_switch *ds, phy_interface_t interface);
+ 	int (*cpu_port_config)(struct dsa_switch *ds, int port);
+ 	bool (*phy_mode_supported)(struct dsa_switch *ds, int port,
+@@ -781,6 +790,10 @@ struct mt753x_info {
+  *			registers
+  * @p6_interface	Holding the current port 6 interface
+  * @p5_intf_sel:	Holding the current port 5 interface select
++ *
++ * @irq:		IRQ number of the switch
++ * @irq_domain:		IRQ domain of the switch irq_chip
++ * @irq_enable:		IRQ enable bits, synced to SYS_INT_EN
+  */
+ struct mt7530_priv {
+ 	struct device		*dev;
+@@ -802,6 +815,9 @@ struct mt7530_priv {
+ 	struct mt7530_port	ports[MT7530_NUM_PORTS];
+ 	/* protect among processes for registers access*/
+ 	struct mutex reg_mutex;
++	int irq;
++	struct irq_domain *irq_domain;
++	u32 irq_enable;
+ };
+ 
+ struct mt7530_hw_vlan_entry {
diff --git a/target/linux/ramips/dts/mt7621.dtsi b/target/linux/ramips/dts/mt7621.dtsi
index 4a3327a364..b784a9d60c 100644
--- a/target/linux/ramips/dts/mt7621.dtsi
+++ b/target/linux/ramips/dts/mt7621.dtsi
@@ -487,6 +487,9 @@
 				mediatek,mcm;
 				resets = <&rstctrl 2>;
 				reset-names = "mcm";
+				interrupt-controller;
+				#interrupt-cells = <1>;
+				interrupts = <GIC_SHARED 23 IRQ_TYPE_LEVEL_HIGH>;
 
 				ports {
 					#address-cells = <1>;