Add supports for ethernet controller HW on Qualcomm Technologies, Inc. SoC.
This driver supports the following features:
1) Checksum offload.
2) Interrupt coalescing support.
3) SGMII phy.
4) phylib interface for external phy

Based on original work by
	Niranjana Vishwanathapura [off-list ref]
	Gilad Avidov [off-list ref]

Signed-off-by: Timur Tabi <redacted>
---

v5:
 - changed author to Timur, added MAINTAINERS entry
 - use phylib, replacing internal phy code
 - added support for EMAC internal SGMII v2
 - fix ~DIS_INT warning
 - update DT bindings, including removing unused properties
 - removed interrupt handler for internal sgmii
 - removed link status check handler/state (replaced with phylib)
 - removed periodic timer handler (replaced with phylib)
 - removed power management code (will be rewritten later)
 - external phy is now required, not optional
 - removed redundant EMAC_STATUS_DOWN status flag
 - removed redundant link status and speed variables
 - removed redundant status bits (vlan strip, promiscuous, loopback, etc)
 - removed useless watchdog status
 - removed command-line parameters
 - cleaned up probe messages
 - removed redundant params from emac_sgmii_link_init()
 - always call netdev_completed_queue() (per review comment)
 - fix emac_napi_rtx() (per review comment)
 - removed max_ints loop in interrupt handler
 - removed redundant mutex around phy read/write calls
 - added lock for reading emac status (per review comment)
 - generate random MAC address if it can't be read from firmware
 - replace EMAC_DMA_ADDR_HI/LO with upper/lower_32_bits
 - don't test return value from platform_get_resource (per review comment)
 - use net_warn_ratelimited (per review comment)
 - don't set the dma masks (will be set by DT or IORT code)
 - remove unused emac_tx_tpd_ts_save()
 - removed redundant local MTU variable

v4:
 - add missing ipv6 header file
 - correct compatible string
 - fix spacing in emac_reg_write arrays
 - drop unnecessary cell-index property
 - remove unsupported DT properties from docs
 - remove GPIO initialization and update docs

v3:
 - remove most of the memory barriers by using the non xxx_relaxed() api.
 - remove RSS and WOL support.
 - correct comments from physical address to dma address.
 - rearrange structs to make them packed.
 - replace polling loops with readl_poll_timeout().
 - remove unnecessary wrapper functions from phy layer.
 - add blank line before return statements.
 - set to null clocks after clk_put().
 - use module_platform_driver() and dma_set_mask_and_coherent()
 - replace long hex bitmasks with BIT() macro.

v2:
 - replace hw bit fields to macros with bitwise operations.
 - change all iterators to unsized types (int)
 - some minor code flow improvements.
 - change return type to void for functions which return value is never
   used.
 - replace instance of xxxxl_relaxed() io followed by mb() with a
   readl()/writel().


 .../devicetree/bindings/net/qcom-emac.txt          |   66 +
 MAINTAINERS                                        |    6 +
 drivers/net/ethernet/qualcomm/Kconfig              |   11 +
 drivers/net/ethernet/qualcomm/Makefile             |    2 +
 drivers/net/ethernet/qualcomm/emac/Makefile        |    7 +
 drivers/net/ethernet/qualcomm/emac/emac-mac.c      | 1674 ++++++++++++++++++++
 drivers/net/ethernet/qualcomm/emac/emac-mac.h      |  284 ++++
 drivers/net/ethernet/qualcomm/emac/emac-phy.c      |  211 +++
 drivers/net/ethernet/qualcomm/emac/emac-phy.h      |   32 +
 drivers/net/ethernet/qualcomm/emac/emac-sgmii.c    |  699 ++++++++
 drivers/net/ethernet/qualcomm/emac/emac-sgmii.h    |   24 +
 drivers/net/ethernet/qualcomm/emac/emac.c          |  798 ++++++++++
 drivers/net/ethernet/qualcomm/emac/emac.h          |  370 +++++
 13 files changed, 4184 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/qcom-emac.txt
 create mode 100644 drivers/net/ethernet/qualcomm/emac/Makefile
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac-mac.c
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac-mac.h
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac-phy.c
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac-phy.h
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac-sgmii.c
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac-sgmii.h
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac.c
 create mode 100644 drivers/net/ethernet/qualcomm/emac/emac.h

diff --git a/Documentation/devicetree/bindings/net/qcom-emac.txt b/Documentation/devicetree/bindings/net/qcom-emac.txt
new file mode 100644
index 0000000..e48a9b9
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/qcom-emac.txt

@@ -0,0 +1,66 @@
+Qualcomm EMAC Gigabit Ethernet Controller
+
+Required properties:
+- compatible : Should be "qcom,fsm9900-emac".
+- reg : Offset and length of the register regions for the device
+- reg-names : Register region names referenced in 'reg' above.
+	Required register resource entries are:
+	"base"   : EMAC controller base register block.
+	"csr"    : EMAC wrapper register block.
+	"sgmii"  : EMAC SGMII PHY register block.
+	Optional register resource entries are:
+	"ptp"    : EMAC PTP (1588) register block.
+- interrupts : Interrupt numbers used by this controller
+- interrupt-names : Interrupt resource names referenced in 'interrupts' above.
+	Required interrupt resource entries are:
+	"emac_core0"   : EMAC core0 interrupt.
+	"sgmii_irq"   : EMAC SGMII interrupt.
+- mac-address               : The 6-byte MAC address. If present, it is the
+			      default MAC address.
+
+Optional properties:
+The external phy child node:
+- compatible : Should be "qcom,fsm9900-emac-phy".
+- reg : The phy address
+
+Example:
+soc {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	emac0: qcom,emac@feb20000 {