[0/6] Add ACPI bindings to the genet

This patch series allows the BCM GENET, as used on the RPi4,
to attach when booted in an ACPI environment. The DSDT entry to
trigger this is seen below. Of note, the first patch adds a
small extension to the mdio layer which allows drivers to find
the mii_bus without firmware assistance. The fifth patch in
the set retrieves the MAC address from the umac registers
rather than carrying it directly in the DSDT. This of course
requires the firmware to pre-program it, so we continue to fall
back on a random one if it appears to be garbage.

v1 -> v2:
     add a core routine mdio_find_bus(), then use it to attach
         to the phy rather than hard-coding the id.
     Broke initial ACPI support patch into 3 parts, two for bcmmii.c
     Address some review comments from Florian
     Lower the severity of a few dev_warns that happen all the time.

+    Device (ETH0)
+    {
+      Name (_HID, "BCM6E4E")
+      Name (_UID, 0)
+      Name (_CCA, 0x0)
+      Method (_STA)
+      {
+        Return (0xf)
+      }
+      Method (_CRS, 0x0, Serialized)
+      {
+        Name (RBUF, ResourceTemplate ()
+        {
+          Memory32Fixed (ReadWrite, 0xFd580000, 0x10000, )
+          Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive) { 0xBD }
+          Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive) { 0xBE }
+        })
+        Return (RBUF)
+      }
+      Name (_DSD, Package () {
+        ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+          Package () {
+          Package () { "phy-mode", "rgmii" },
+        }
+      })
+    }
+

Jeremy Linton (6):
  mdio_bus: Add generic mdio_find_bus()
  net: bcmgenet: refactor phy mode configuration
  net: bcmgenet: enable automatic phy discovery
  net: bcmgenet: Initial bcmgenet ACPI support
  net: bcmgenet: Fetch MAC address from the adapter
  net: bcmgenet: reduce severity of missing clock warnings

 .../net/ethernet/broadcom/genet/bcmgenet.c    | 66 +++++++++++-----
 drivers/net/ethernet/broadcom/genet/bcmmii.c  | 79 +++++++++++++------
 drivers/net/phy/mdio_bus.c                    | 17 ++++
 include/linux/phy.h                           |  1 +
 4 files changed, 122 insertions(+), 41 deletions(-)