Merge branch 'phylib-hard-resetting-devices'

Geert Uytterhoeven says:

====================
Teach phylib hard-resetting devices

This patch series adds optional PHY reset support to phylib.

The first two patches are destined for David's net-next tree. They add
core PHY reset code, and update a driver that currently uses its own
reset code.

The last two patches are destined for Simon's renesas tree.  They add
properties to describe the EthernetAVB PHY reset topology to the common
Salvator-X/XS and ULCB DTS files, which solves two issues:
  1. On Salvator-XS, the enable pin of the regulator providing PHY power
     is connected to PRESETn, and PSCI powers down the SoC during system
     suspend.  Hence a PHY reset is needed to restore network
     functionality after system resume.
  2. Linux should not rely on the boot loader having reset the PHY, but
     should reset the PHY during driver probe.

Changes compared to v3:
  - Remove Florian's Acked-by,
  - Add missing #include <linux/gpio/consumer.h>,
  - Re-add the gpiod check, as the dummy gpiod_set_value() for !GPIOLIB
    does not ignore NULL, and calls WARN_ON(1),
  - Do not reassert the reset signal if {mdio,phy}_probe() or
    phy_device_register() succeeded, as that may destroy initial setup,
  - Do not deassert the reset signal in {mdio,phy}_remove(), as it
    should already be deasserted,
  - Bring the PHY back into reset state in phy_device_remove(),
  - Move/consolidate GPIO descriptor acquiring code from
    of_mdiobus_register_phy() and of_mdiobus_register_device() to
    mdiobus_register_device().
    Note that this changes behavior slightly, in that the reset signal
    is now also asserted when called from of_mdiobus_register_device().
  - Add Reviewed-by,

Changes compared to v2, as sent by Sergei Shtylyov:
  - Fix fwnode_get_named_gpiod() call due to added parameters (which
    allowed to eliminate the gpiod_direction_output() call),
  - Rebased, refreshed, reworded,
  - Take over from Sergei,
  - Add Acked-by,
  - Remove unneeded gpiod check, as gpiod_set_value() handles NULL fine,
  - Handle fwnode_get_named_gpiod() errors correctly:
      - -ENOENT is ignored (the GPIO is optional), and turned into NULL,
	which allowed to remove all later !IS_ERR() checks,
      - Other errors (incl. -EPROBE_DEFER) are propagated,
  - Extract DTS patches from series "[PATCH 0/4] ravb: Add PHY reset
    support" (https://www.spinics.net/lists/netdev/msg457308.html), and
    incorporate in this series, after moving reset-gpios from the
    ethernet to the ethernet-phy node.

Given (1) the new reset-gpios DT property in the PHY node follows
established practises, (2) the DT binding change in the first patch has
been acked by Rob, and (3) the DTS patch does not cause any regressions
if it is applied before the PHY driver patches, the DTS patches can be
applied independently.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index ca08ab16ecdc..92d4e55ffe67 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -12,6 +12,7 @@
 #include <uapi/linux/mdio.h>
 #include <linux/mod_devicetable.h>
 
+struct gpio_desc;
 struct mii_bus;
 
 /* Multiple levels of nesting are possible. However typically this is
@@ -39,6 +40,7 @@ struct mdio_device {
 	/* Bus address of the MDIO device (0-31) */
 	int addr;
 	int flags;
+	struct gpio_desc *reset;
 };
 #define to_mdio_device(d) container_of(d, struct mdio_device, dev)
 
@@ -71,6 +73,7 @@ void mdio_device_free(struct mdio_device *mdiodev);
 struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr);
 int mdio_device_register(struct mdio_device *mdiodev);
 void mdio_device_remove(struct mdio_device *mdiodev);
+void mdio_device_reset(struct mdio_device *mdiodev, int value);
 int mdio_driver_register(struct mdio_driver *drv);
 void mdio_driver_unregister(struct mdio_driver *drv);
 int mdio_device_bus_match(struct device *dev, struct device_driver *drv);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 7570cb838410..d3037e2ffbc4 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -854,6 +854,11 @@ int phy_aneg_done(struct phy_device *phydev);
 int phy_stop_interrupts(struct phy_device *phydev);
 int phy_restart_aneg(struct phy_device *phydev);
 
+static inline void phy_device_reset(struct phy_device *phydev, int value)
+{
+	mdio_device_reset(&phydev->mdio, value);
+}
+
 #define phydev_err(_phydev, format, args...)	\
 	dev_err(&_phydev->mdio.dev, format, ##args)