drivers: Add Ethernet PHY API

This commit adds support for Ethernet PHY drivers via a PHY API.

It also includes a driver for a generic MII compliant PHY
which supports most PHYs on the market.

Separating PHY driver from the SoC specific Ethernet driver
simplifies the Ethernet driver code and enables code re-use.
Drivers for specific PHYs with more advanced features, such as
RGMII delay in PHY can be developed independent of the Ethernet
MAC driver.

Signed-off-by: Arvin Farahmand <[email protected]>

Author: arvinf

CODEOWNERS

@@ -222,6 +222,7 @@
 /drivers/ethernet/*stm32*                 @Nukersson @lochej
 /drivers/ethernet/*w5500*                 @parthitce
 /drivers/ethernet/*xlnx_gem*              @ibirnbaum
+/drivers/ethernet/phy/                    @rlubos @tbursztyka @arvinf
 /drivers/mdio/                            @rlubos @tbursztyka @arvinf
 /drivers/flash/                           @nashif @nvlsianpu
 /drivers/flash/*b91*                      @yurvyn

drivers/ethernet/CMakeLists.txt

@@ -40,3 +40,5 @@ if(CONFIG_ETH_NATIVE_POSIX)
 		eth_native_posix_adapt.c
 		)
 endif()
+
+add_subdirectory(phy)

drivers/ethernet/Kconfig

@@ -59,4 +59,6 @@ source "drivers/ethernet/Kconfig.w5500"
 source "drivers/ethernet/Kconfig.dsa"
 source "drivers/ethernet/Kconfig.xlnx_gem"
 
+source "drivers/ethernet/phy/Kconfig"
+
 endmenu # "Ethernet Drivers"

drivers/ethernet/phy/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_PHY_GENERIC_MII	 phy_mii.c)

drivers/ethernet/phy/Kconfig

@@ -0,0 +1,47 @@
+# Ethernet PHY drivers configuration options
+
+# Copyright (c) 2021 IP-Logix Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+menu "Ethernet PHY Drivers"
+	depends on NET_L2_ETHERNET
+
+module = PHY
+module-dep = LOG
+module-str = Log level for Ethernet PHY driver
+module-help = Sets log level for Ethernet PHY Device Drivers.
+source "subsys/net/Kconfig.template.log_config.net"
+
+config PHY_INIT_PRIORITY
+	int "Ethernet PHY driver init priority"
+	default 70
+	help
+	  Ethernet PHY device driver initialization priority.
+	  Do not mess with it unless you know what you are doing.
+	  Note that the priority needs to be lower than the net stack
+	  so that it can start before the networking sub-system.
+
+config PHY_GENERIC_MII
+	bool "Generic MII PHY Driver"
+	default y
+	depends on MDIO
+	help
+	  This is a generic MII PHY interface that communicates with the
+	  PHY using the MDIO bus.
+
+config PHY_AUTONEG_TIMEOUT_MS
+	int "Auto-negotiation timeout value in milliseconds"
+	default 4000
+	help
+	  Maximum duration of auto-negotiation sequence in milliseconds
+	  before the process fails
+
+config PHY_MONITOR_PERIOD
+	int "Monitor task execution period"
+	default 500
+	help
+	  Monitor task execution period in milliseconds. The monitor task is
+	  periodically executed to detect and report any changes in the
+	  PHY link status to the operating system.
+
+endmenu # "Ethernet PHY Drivers"