Re: [PATCH net-next 2/4] net: dsa: mt7530: add interrupt support

Vladimir Oltean
2021-05-06T11:42:32Z

On Thu, Apr 29, 2021 at 02:21:28PM +0800, DENG Qingfang wrote:
> 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>
> ---
> RFC v4 -> PATCH v1:
> - Cosmetic fixes.
>
> drivers/net/dsa/Kconfig | 1 +
> drivers/net/dsa/mt7530.c | 264 +++++++++++++++++++++++++++++++++++----
> drivers/net/dsa/mt7530.h | 20 ++-
> 3 files changed, 257 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
> index a5f1aa911fe2..264384449f09 100644
> --- a/drivers/net/dsa/Kconfig
> +++ b/drivers/net/dsa/Kconfig
> @@ -36,6 +36,7 @@ config NET_DSA_LANTIQ_GSWIP
> config NET_DSA_MT7530
> tristate "MediaTek MT753x and MT7621 Ethernet switch support"
> select NET_DSA_TAG_MTK
> + select MEDIATEK_PHY

I'm pretty much the last person you'd want to ask for Kconfig advice,
but I think that you should only select the Kconfig options which have
no dependencies of their own, and MEDIATEK_PHY isn't like that. Do you
ensure through some other way that its dependencies are always satisfied?

> help
> This enables support for the MediaTek MT7530, MT7531, and MT7621
> Ethernet switch chips.
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index 96f7c9eede35..db838343fb05 100644
> --- 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>
> @@ -596,18 +597,14 @@ 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);
> }
>
> @@ -785,9 +782,8 @@ mt7531_ind_c22_phy_write(struct mt7530_priv *priv, int port, int regnum,
> }
>
> 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;
>
> @@ -803,10 +799,9 @@ mt7531_ind_phy_read(struct dsa_switch *ds, int port, int regnum)
> }
>
> 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;
>
> @@ -822,6 +817,22 @@ mt7531_ind_phy_write(struct dsa_switch *ds, int port, int regnum,
> 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)
> @@ -1828,6 +1839,210 @@ mt7530_setup_gpio(struct mt7530_priv *priv)
> }
> #endif /* CONFIG_GPIOLIB */
>
> +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;

Interesting use of "static".

> + 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 = mdiobus_register(bus);
> + if (ret) {
> + dev_err(dev, "failed to register MDIO bus: %d\n", ret);
> + if (priv->irq)
> + mt7530_free_mdio_irq(priv);
> + }
> +
> + return ret;
> +}
> +

Looks good.

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>