net: mdiobus: add reset-post-delay-us handling

Load new "reset-post-delay-us" value from MDIO properties,
and if configured to a greater then zero delay do a
flexible sleeping delay after MDIO bus reset deassert.
This allows devices to exit reset state before start
bus communication.

Signed-off-by: Bruno Thomsen <bruno.thomsen@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 5df3782b05b4c566a5ab274a69e19445a95c754d..0af20faad69df21781345727762a403317a2794b 100644 (file)
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -556,6 +556,8 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
                gpiod_set_value_cansleep(gpiod, 1);
                fsleep(bus->reset_delay_us);
                gpiod_set_value_cansleep(gpiod, 0);
+               if (bus->reset_post_delay_us > 0)
+                       fsleep(bus->reset_post_delay_us);
        }
 
        if (bus->reset) {

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index eb84507de28aebc9966434eac5a75136a5c18884..cb32d7ef49382f05d3e8065f9c5f316c8735ad3c 100644 (file)
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -268,6 +268,8 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
        /* Get bus level PHY reset GPIO details */
        mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY;
        of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us);
+       mdio->reset_post_delay_us = 0;
+       of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
 
        /* Register the MDIO bus */
        rc = mdiobus_register(mdio);

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 0403eb7999132b4a92459583971d1763543f212e..3a09d2bf69ea48f7ccfcc17226fcae354d08ca88 100644 (file)
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -293,6 +293,8 @@ struct mii_bus {
 
        /* GPIO reset pulse width in microseconds */
        int reset_delay_us;
+       /* GPIO reset deassert delay in microseconds */
+       int reset_post_delay_us;
        /* RESET GPIO descriptor pointer */
        struct gpio_desc *reset_gpiod;