[PATCH v2 3/4 net-next] net: mdiobus: add reset-post-delay-us handling

[Bruno Thomsen <bruno.thomsen@gmail.com>]

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>
---
 drivers/net/phy/mdio_bus.c | 2 ++
 drivers/of/of_mdio.c       | 2 ++
 include/linux/phy.h        | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 5df3782b05b4..0af20faad69d 100644
--- 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 eb84507de28a..cb32d7ef4938 100644
--- 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 0403eb799913..3a09d2bf69ea 100644
--- 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;
 
-- 
2.26.2