[PATCH net-next 1/4] net: phylink: support for link gpio interrupt

[Russell King]

Add support for using GPIO interrupts with a fixed-link GPIO rather than
polling the GPIO every second and invoking the phylink resolution.  This
avoids unnecessary calls to mac_config().

Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
---
 drivers/net/phy/phylink.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 74983593834b..bdee5f307a7f 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -52,6 +52,7 @@ struct phylink {
        /* The link configuration settings */
        struct phylink_link_state link_config;
        struct gpio_desc *link_gpio;
+       unsigned int link_irq;
        struct timer_list link_poll;
        void (*get_fixed_state)(struct net_device *dev,
                                struct phylink_link_state *s);
@@ -608,7 +609,7 @@ void phylink_destroy(struct phylink *pl)
 {
        if (pl->sfp_bus)
                sfp_unregister_upstream(pl->sfp_bus);
-       if (!IS_ERR_OR_NULL(pl->link_gpio))
+       if (pl->link_gpio)
                gpiod_put(pl->link_gpio);
 
        cancel_work_sync(&pl->resolve);
@@ -871,6 +872,15 @@ void phylink_mac_change(struct phylink *pl, bool up)
 }
 EXPORT_SYMBOL_GPL(phylink_mac_change);
 
+static irqreturn_t phylink_link_handler(int irq, void *data)
+{
+       struct phylink *pl = data;
+
+       phylink_run_resolve(pl);
+
+       return IRQ_HANDLED;
+}
+
 /**
  * phylink_start() - start a phylink instance
  * @pl: a pointer to a &struct phylink returned from phylink_create()
@@ -906,7 +916,22 @@ void phylink_start(struct phylink *pl)
        clear_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state);
        phylink_run_resolve(pl);
 
-       if (pl->link_an_mode == MLO_AN_FIXED && !IS_ERR(pl->link_gpio))
+       if (pl->link_an_mode == MLO_AN_FIXED && pl->link_gpio) {
+               int irq = gpiod_to_irq(pl->link_gpio);
+
+               if (irq > 0) {
+                       if (!request_irq(irq, phylink_link_handler,
+                                        IRQF_TRIGGER_RISING |
+                                        IRQF_TRIGGER_FALLING,
+                                        "netdev link", pl))
+                               pl->link_irq = irq;
+                       else
+                               irq = 0;
+               }
+               if (irq <= 0)
+                       mod_timer(&pl->link_poll, jiffies + HZ);
+       }
+       if (pl->link_an_mode == MLO_AN_FIXED && pl->get_fixed_state)
                mod_timer(&pl->link_poll, jiffies + HZ);
        if (pl->sfp_bus)
                sfp_upstream_start(pl->sfp_bus);
@@ -932,8 +957,11 @@ void phylink_stop(struct phylink *pl)
                phy_stop(pl->phydev);
        if (pl->sfp_bus)
                sfp_upstream_stop(pl->sfp_bus);
-       if (pl->link_an_mode == MLO_AN_FIXED && !IS_ERR(pl->link_gpio))
-               del_timer_sync(&pl->link_poll);
+       del_timer_sync(&pl->link_poll);
+       if (pl->link_irq) {
+               free_irq(pl->link_irq, pl);
+               pl->link_irq = 0;
+       }
 
        phylink_run_resolve_and_disable(pl, PHYLINK_DISABLE_STOPPED);
 }
-- 
2.7.4