[v3] 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>
---
 ...net-dsa-mt7530-add-interrupt-support.patch | 417 ++++++++++++++++++
 target/linux/ramips/dts/mt7621.dtsi           |   3 +
 2 files changed, 420 insertions(+)
 create mode 100644 target/linux/generic/backport-5.10/772-v5.14-net-dsa-mt7530-add-interrupt-support.patch

On Thu, Feb 10, 2022 at 12:00:25PM +0800, DENG Qingfang wrote:
> 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.

I've tried building this and it breaks. See comments inline:
> 
> Signed-off-by: DENG Qingfang <dqfext@gmail.com>
> ---
>  ...net-dsa-mt7530-add-interrupt-support.patch | 417 ++++++++++++++++++
>  target/linux/ramips/dts/mt7621.dtsi           |   3 +
>  2 files changed, 420 insertions(+)
>  create mode 100644 target/linux/generic/backport-5.10/772-v5.14-net-dsa-mt7530-add-interrupt-support.patch
> 
> 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..47ac779efa
> --- /dev/null
> +++ b/target/linux/generic/backport-5.10/772-v5.14-net-dsa-mt7530-add-interrupt-support.patch
> @@ -0,0 +1,417 @@
> +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 | 263 +++++++++++++++++++++++++++++++++++----
> + drivers/net/dsa/mt7530.h |  21 +++-
> + 2 files changed, 255 insertions(+), 29 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)
> +@@ -1991,6 +2002,211 @@ mt7530_setup(struct dsa_switch *ds)
> + 	return 0;
> + }
> + 
> ++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)

This function appears to be unused.

At top level:
drivers/net/dsa/mt7530.c:2169:1: warning: 'mt7530_free_irq' defined but not used [-Wunused-function]
 2169 | 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(bus);

Did you mean
mdiobus_register(bus);
?

Or
devm_mdiobus_register(dev, bus);
?

drivers/net/dsa/mt7530.c: In function 'mt7530_setup_mdio':
drivers/net/dsa/mt7530.c:2200:40: error: macro "devm_mdiobus_register" requires 2 arguments, but only 1 given
 2200 |         ret = devm_mdiobus_register(bus);
      |                                        ^
In file included from ./include/linux/of_mdio.h:12,
                 from drivers/net/dsa/mt7530.c:14:
./include/linux/phy.h:394: note: macro "devm_mdiobus_register" defined here
  394 | #define devm_mdiobus_register(dev, bus) \
      | 
drivers/net/dsa/mt7530.c:2200:15: error: 'devm_mdiobus_register' undeclared (first use in this function); did you mean 'devm_of_mdiobus_register'?
 2200 |         ret = devm_mdiobus_register(bus);
      |               ^~~~~~~~~~~~~~~~~~~~~
      |               devm_of_mdiobus_register
drivers/net/dsa/mt7530.c:2200:15: note: each undeclared identifier is reported only once for each function it appears in
At top level:

> ++	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
> + mt7531_setup(struct dsa_switch *ds)
> + {
> +@@ -2798,24 +3014,19 @@ static int
> + mt753x_setup(struct dsa_switch *ds)
> + {
> + 	struct mt7530_priv *priv = ds->priv;
> ++	int ret = priv->info->sw_setup(ds);
> ++	if (ret)
> ++		return ret;
> + 
> +-	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;
> +-
> +-	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,
> +--- 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 +729,9 @@ static const char *p5_intf_modes(unsigne
> + 	}
> + }
> + 
> ++/* Forward declaration */
> ++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 +756,8 @@ 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 +791,10 @@ 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 +816,9 @@ 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 7992f47993..7bd3b0f871 100644
> --- a/target/linux/ramips/dts/mt7621.dtsi
> +++ b/target/linux/ramips/dts/mt7621.dtsi
> @@ -514,6 +514,9 @@
>  				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>;
> -- 
> 2.25.1
>