[PATCH net-next v5 00/14] Add support for OPEN Alliance 10BASE-T1x MACPHY Serial Interface

@@ -87,6 +87,7 @@ Contents:
    nexthop-group-resilient
    nf_conntrack-sysctl
    nf_flowtable
+   oa-tc6-framework
    openvswitch
    operstates
    packet_mmap

@@ -0,0 +1,497 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+=========================================================================
+OPEN Alliance 10BASE-T1x MAC-PHY Serial Interface (TC6) Framework Support
+=========================================================================
+
+Introduction
+------------
+
+The IEEE 802.3cg project defines two 10 Mbit/s PHYs operating over a
+single pair of conductors. The 10BASE-T1L (Clause 146) is a long reach
+PHY supporting full duplex point-to-point operation over 1 km of single
+balanced pair of conductors. The 10BASE-T1S (Clause 147) is a short reach
+PHY supporting full / half duplex point-to-point operation over 15 m of
+single balanced pair of conductors, or half duplex multidrop bus
+operation over 25 m of single balanced pair of conductors.
+
+Furthermore, the IEEE 802.3cg project defines the new Physical Layer
+Collision Avoidance (PLCA) Reconciliation Sublayer (Clause 148) meant to
+provide improved determinism to the CSMA/CD media access method. PLCA
+works in conjunction with the 10BASE-T1S PHY operating in multidrop mode.
+
+The aforementioned PHYs are intended to cover the low-speed / low-cost
+applications in industrial and automotive environment. The large number
+of pins (16) required by the MII interface, which is specified by the
+IEEE 802.3 in Clause 22, is one of the major cost factors that need to be
+addressed to fulfil this objective.
+
+The MAC-PHY solution integrates an IEEE Clause 4 MAC and a 10BASE-T1x PHY
+exposing a low pin count Serial Peripheral Interface (SPI) to the host
+microcontroller. This also enables the addition of Ethernet functionality
+to existing low-end microcontrollers which do not integrate a MAC
+controller.
+
+Overview
+--------
+
+The MAC-PHY is specified to carry both data (Ethernet frames) and control
+(register access) transactions over a single full-duplex serial peripheral
+interface.
+
+Protocol Overview
+-----------------
+
+Two types of transactions are defined in the protocol: data transactions
+for Ethernet frame transfers and control transactions for register
+read/write transfers. A chunk is the basic element of data transactions
+and is composed of 4 bytes of overhead plus 64 bytes of payload size for
+each chunk. Ethernet frames are transferred over one or more data chunks.
+Control transactions consist of one or more register read/write control
+commands.
+
+SPI transactions are initiated by the SPI host with the assertion of CSn
+low to the MAC-PHY and ends with the deassertion of CSn high. In between
+each SPI transaction, the SPI host may need time for additional
+processing and to setup the next SPI data or control transaction.
+
+SPI data transactions consist of an equal number of transmit (TX) and
+receive (RX) chunks. Chunks in both transmit and receive directions may
+or may not contain valid frame data independent from each other, allowing
+for the simultaneous transmission and reception of different length
+frames.
+
+Each transmit data chunk begins with a 32-bit data header followed by a
+data chunk payload on MOSI. The data header indicates whether transmit
+frame data is present and provides the information to determine which
+bytes of the payload contain valid frame data.
+
+In parallel, receive data chunks are received on MISO. Each receive data
+chunk consists of a data chunk payload ending with a 32-bit data footer.
+The data footer indicates if there is receive frame data present within
+the payload or not and provides the information to determine which bytes
+of the payload contain valid frame data.
+
+Reference
+---------
+
+10BASE-T1x MAC-PHY Serial Interface Specification,
+
+Link: https://opensig.org/download/document/OPEN_Alliance_10BASET1x_MAC-PHY_Serial_Interface_V1.1.pdf
+
+Hardware Architecture
+---------------------
+
+.. code-block:: none
+
+  +----------+      +-------------------------------------+
+  |          |      |                MAC-PHY              |
+  |          |<---->| +-----------+  +-------+  +-------+ |
+  | SPI Host |      | | SPI Slave |  |  MAC  |  |  PHY  | |
+  |          |      | +-----------+  +-------+  +-------+ |
+  +----------+      +-------------------------------------+
+
+Software Architecture
+---------------------
+
+.. code-block:: none
+
+  +----------------------------------------------------------+
+  |                 Networking Subsystem                     |
+  +----------------------------------------------------------+
+            / \                             / \
+             |                               |
+             |                               |
+            \ /                              |
+  +----------------------+     +-----------------------------+
+  |     MAC Driver       |<--->| OPEN Alliance TC6 Framework |
+  +----------------------+     +-----------------------------+
+            / \                             / \
+             |                               |
+             |                               |
+             |                              \ /
+  +----------------------------------------------------------+
+  |                    SPI Subsystem                         |
+  +----------------------------------------------------------+
+                          / \
+                           |
+                           |
+                          \ /
+  +----------------------------------------------------------+
+  |                10BASE-T1x MAC-PHY Device                 |
+  +----------------------------------------------------------+
+
+Implementation
+--------------
+
+MAC Driver
+~~~~~~~~~~
+
+- Probed by SPI subsystem.
+
+- Initializes OA TC6 framework for the MAC-PHY.
+
+- Registers and configures the network device.
+
+- Sends the tx ethernet frames from n/w subsystem to OA TC6 framework.
+
+OPEN Alliance TC6 Framework
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Initializes PHYLIB interface.
+
+- Registers mac-phy interrupt.
+
+- Performs mac-phy register read/write operation using the control
+  transaction protocol specified in the OPEN Alliance 10BASE-T1x MAC-PHY
+  Serial Interface specification.
+
+- Performs Ethernet frames transaction using the data transaction protocol
+  for Ethernet frames specified in the OPEN Alliance 10BASE-T1x MAC-PHY
+  Serial Interface specification.
+
+- Forwards the received Ethernet frame from 10Base-T1x MAC-PHY to n/w
+  subsystem.
+
+Data Transaction
+~~~~~~~~~~~~~~~~
+
+The Ethernet frames that are typically transferred from the SPI host to
+the MAC-PHY will be converted into multiple transmit data chunks. Each
+transmit data chunk will have a 4 bytes header which contains the
+information needed to determine the validity and the location of the
+transmit frame data within the 64 bytes data chunk payload.
+
+.. code-block:: none
+
+  +---------------------------------------------------+
+  |                     Tx Chunk                      |
+  | +---------------------------+  +----------------+ |   MOSI
+  | | 64 bytes chunk payload    |  | 4 bytes header | |------------>
+  | +---------------------------+  +----------------+ |
+  +---------------------------------------------------+
+
+4 bytes header contains the below fields,
+
+DNC (Bit 31) - Data-Not-Control flag. This flag specifies the type of SPI
+               transaction. For TX data chunks, this bit shall be ’1’.
+               0 - Control command
+               1 - Data chunk
+
+SEQ (Bit 30) - Data Chunk Sequence. This bit is used to indicate an
+               even/odd transmit data chunk sequence to the MAC-PHY.
+
+NORX (Bit 29) - No Receive flag. The SPI host may set this bit to prevent
+                the MAC-PHY from conveying RX data on the MISO for the
+                current chunk (DV = 0 in the footer), indicating that the
+                host would not process it. Typically, the SPI host should
+                set NORX = 0 indicating that it will accept and process
+                any receive frame data within the current chunk.
+
+RSVD (Bit 28..24) - Reserved: All reserved bits shall be ‘0’.
+
+VS (Bit 23..22) - Vendor Specific. These bits are implementation specific.
+                  If the MAC-PHY does not implement these bits, the host
+                  shall set them to ‘0’.
+
+DV (Bit 21) - Data Valid flag. The SPI host uses this bit to indicate
+              whether the current chunk contains valid transmit frame data
+              (DV = 1) or not (DV = 0). When ‘0’, the MAC-PHY ignores the
+              chunk payload. Note that the receive path is unaffected by
+              the setting of the DV bit in the data header.
+
+SV (Bit 20) - Start Valid flag. The SPI host shall set this bit when the
+              beginning of an Ethernet frame is present in the current
+              transmit data chunk payload. Otherwise, this bit shall be
+              zero. This bit is not to be confused with the Start-of-Frame
+              Delimiter (SFD) byte described in IEEE 802.3 [2].
+
+SWO (Bit 19..16) - Start Word Offset. When SV = 1, this field shall
+                   contain the 32-bit word offset into the transmit data
+                   chunk payload that points to the start of a new
+                   Ethernet frame to be transmitted. The host shall write
+                   this field as zero when SV = 0.
+
+RSVD (Bit 15) - Reserved: All reserved bits shall be ‘0’.
+
+EV (Bit 14) - End Valid flag. The SPI host shall set this bit when the end
+              of an Ethernet frame is present in the current transmit data
+              chunk payload. Otherwise, this bit shall be zero.
+
+EBO (Bit 13..8) - End Byte Offset. When EV = 1, this field shall contain
+                  the byte offset into the transmit data chunk payload
+                  that points to the last byte of the Ethernet frame to
+                  transmit. This field shall be zero when EV = 0.
+
+TSC (Bit 7..6) - Timestamp Capture. Request a timestamp capture when the
+                 frame is transmitted onto the network.
+                 00 - Do not capture a timestamp
+                 01 - Capture timestamp into timestamp capture register A
+                 10 - Capture timestamp into timestamp capture register B
+                 11 - Capture timestamp into timestamp capture register C
+
+RSVD (Bit 5..1) - Reserved: All reserved bits shall be ‘0’.
+
+P (Bit 0) - Parity. Parity bit calculated over the transmit data header.
+            Method used is odd parity.
+
+The number of buffers available in the MAC-PHY to store the incoming
+transmit data chunk payloads is represented as transmit credits. The
+available transmit credits in the MAC-PHY can be read either from the
+Buffer Status Register or footer (Refer below for the footer info)
+received from the MAC-PHY. The SPI host should not write more data chunks
+than the available transmit credits as this will lead to transmit buffer
+overflow error.
+
+In case the previous data footer had no transmit credits available and
+once the transmit credits become available for transmitting transmit data
+chunks, the MAC-PHY interrupt is asserted to SPI host. On reception of the
+first data header this interrupt will be deasserted and the received
+footer for the first data chunk will have the transmit credits available
+information.
+
+The Ethernet frames that are typically transferred from MAC-PHY to SPI
+host will be sent as multiple receive data chunks. Each receive data
+chunk will have 64 bytes of data chunk payload followed by 4 bytes footer
+which contains the information needed to determine the validity and the
+location of the receive frame data within the 64 bytes data chunk payload.
+
+.. code-block:: none
+
+  +---------------------------------------------------+
+  |                     Rx Chunk                      |
+  | +----------------+  +---------------------------+ |   MISO
+  | | 4 bytes footer |  | 64 bytes chunk payload    | |------------>
+  | +----------------+  +---------------------------+ |
+  +---------------------------------------------------+
+
+4 bytes footer contains the below fields,
+
+EXST (Bit 31) - Extended Status. This bit is set when any bit in the
+                STATUS0 or STATUS1 registers are set and not masked.
+
+HDRB (Bit 30) - Received Header Bad. When set, indicates that the MAC-PHY
+                received a control or data header with a parity error.
+
+SYNC (Bit 29) - Configuration Synchronized flag. This bit reflects the
+                state of the SYNC bit in the CONFIG0 configuration
+                register (see Table 12). A zero indicates that the MAC-PHY
+                configuration may not be as expected by the SPI host.
+                Following configuration, the SPI host sets the
+                corresponding bitin the configuration register which is
+                reflected in this field.
+
+RCA (Bit 28..24) - Receive Chunks Available. The RCA field indicates to
+                   the SPI host the minimum number of additional receive
+                   data chunks of frame data that are available for
+                   reading beyond the current receive data chunk. This
+                   field is zero when there is no receive frame data
+                   pending in the MAC-PHY’s buffer for reading.
+
+VS (Bit 23..22) - Vendor Specific. These bits are implementation specific.
+                  If not implemented, the MAC-PHY shall set these bits to
+                  ‘0’.
+
+DV (Bit 21) - Data Valid flag. The MAC-PHY uses this bit to indicate
+              whether the current receive data chunk contains valid
+              receive frame data (DV = 1) or not (DV = 0). When ‘0’, the
+              SPI host shall ignore the chunk payload.
+
+SV (Bit 20) - Start Valid flag. The MAC-PHY sets this bit when the current
+              chunk payload contains the start of an Ethernet frame.
+              Otherwise, this bit is zero. The SV bit is not to be
+              confused with the Start-of-Frame Delimiter (SFD) byte
+              described in IEEE 802.3 [2].
+
+SWO (Bit 19..16) - Start Word Offset. When SV = 1, this field contains the
+                   32-bit word offset into the receive data chunk payload
+                   containing the first byte of a new received Ethernet
+                   frame. When a receive timestamp has been added to the
+                   beginning of the received Ethernet frame (RTSA = 1)
+                   then SWO points to the most significant byte of the
+                   timestamp. This field will be zero when SV = 0.
+
+FD (Bit 15) - Frame Drop. When set, this bit indicates that the MAC has
+              detected a condition for which the SPI host should drop the
+              received Ethernet frame. This bit is only valid at the end
+              of a received Ethernet frame (EV = 1) and shall be zero at
+              all other times.
+
+EV (Bit 14) - End Valid flag. The MAC-PHY sets this bit when the end of a
+              received Ethernet frame is present in this receive data
+              chunk payload.
+
+EBO (Bit 13..8) - End Byte Offset: When EV = 1, this field contains the
+                  byte offset into the receive data chunk payload that
+                  locates the last byte of the received Ethernet frame.
+                  This field is zero when EV = 0.
+
+RTSA (Bit 7) - Receive Timestamp Added. This bit is set when a 32-bit or
+               64-bit timestamp has been added to the beginning of the
+               received Ethernet frame. The MAC-PHY shall set this bit to
+               zero when SV = 0.
+
+RTSP (Bit 6) - Receive Timestamp Parity. Parity bit calculated over the
+               32-bit/64-bit timestamp added to the beginning of the
+               received Ethernet frame. Method used is odd parity. The
+               MAC-PHY shall set this bit to zero when RTSA = 0.
+
+TXC (Bit 5..1) - Transmit Credits. This field contains the minimum number
+                 of transmit data chunks of frame data that the SPI host
+                 can write in a single transaction without incurring a
+                 transmit buffer overflow error.
+
+P (Bit 0) - Parity. Parity bit calculated over the receive data footer.
+            Method used is odd parity.
+
+SPI host will initiate the data receive transaction based on the receive
+chunks available in the MAC-PHY which is provided in the receive chunk
+footer (RCA - Receive Chunks Available). SPI host will create data invalid
+transmit data chunks (empty chunks) or data valid transmit data chunks in
+case there are valid Ethernet frames to transmit to the MAC-PHY. The
+receive chunks available in MAC-PHY can be read either from the Buffer
+Status Register or footer.
+
+In case the previous data footer had no receive data chunks available and
+once the receive data chunks become available again for reading, the
+MAC-PHY interrupt is asserted to SPI host. On reception of the first data
+header this interrupt will be deasserted and the received footer for the
+first data chunk will have the receive chunks available information.
+
+MAC-PHY Interrupt
+~~~~~~~~~~~~~~~~~
+
+The MAC-PHY interrupt is asserted when the following conditions are met.
+
+Receive chunks available - This interrupt is asserted when the previous
+data footer had no receive data chunks available and once the receive
+data chunks become available for reading. On reception of the first data
+header this interrupt will be deasserted.
+
+Transmit chunk credits available - This interrupt is asserted when the
+previous data footer indicated no transmit credits available and once the
+transmit credits become available for transmitting transmit data chunks.
+On reception of the first data header this interrupt will be deasserted.
+
+Extended status event - This interrupt is asserted when the previous data
+footer indicated no extended status and once the extended event become
+available. In this case the host should read status #0 register to know
+the corresponding error/event. On reception of the first data header this
+interrupt will be deasserted.
+
+Control Transaction
+~~~~~~~~~~~~~~~~~~~
+
+4 bytes control header contains the below fields,
+
+DNC (Bit 31) - Data-Not-Control flag. This flag specifies the type of SPI
+               transaction. For control commands, this bit shall be ‘0’.
+               0 - Control command
+               1 - Data chunk
+
+HDRB (Bit 30) - Received Header Bad. When set by the MAC-PHY, indicates
+                that a header was received with a parity error. The SPI
+                host should always clear this bit. The MAC-PHY ignores the
+                HDRB value sent by the SPI host on MOSI.
+
+WNR (Bit 29) - Write-Not-Read. This bit indicates if data is to be written
+               to registers (when set) or read from registers
+               (when clear).
+
+AID (Bit 28) - Address Increment Disable. When clear, the address will be
+               automatically post-incremented by one following each
+               register read or write. When set, address auto increment is
+               disabled allowing successive reads and writes to occur at
+               the same register address.
+
+MMS (Bit 27..24) - Memory Map Selector. This field selects the specific
+                   register memory map to access.
+
+ADDR (Bit 23..8) - Address. Address of the first register within the
+                   selected memory map to access.
+
+LEN (Bit 7..1) - Length. Specifies the number of registers to read/write.
+                 This field is interpreted as the number of registers
+                 minus 1 allowing for up to 128 consecutive registers read
+                 or written starting at the address specified in ADDR. A
+                 length of zero shall read or write a single register.
+
+P (Bit 0) - Parity. Parity bit calculated over the control command header.
+            Method used is odd parity.
+
+Control transactions consist of one or more control commands. Control
+commands are used by the SPI host to read and write registers within the
+MAC-PHY. Each control commands are composed of a 4 bytes control command
+header followed by register write data in case of control write command.
+
+The MAC-PHY ignores the final 4 bytes of data from the SPI host at the end
+of the control write command. The control write command is also echoed
+from the MAC-PHY back to the SPI host to identify which register write
+failed in case of any bus errors. The echoed Control write command will
+have the first 4 bytes unused value to be ignored by the SPI host
+followed by 4 bytes echoed control header followed by echoed register
+write data. Control write commands can write either a single register or
+multiple consecutive registers. When multiple consecutive registers are
+written, the address is automatically post-incremented by the MAC-PHY.
+Writing to any unimplemented or undefined registers shall be ignored and
+yield no effect.
+
+The MAC-PHY ignores all data from the SPI host following the control
+header for the remainder of the control read command. The control read
+command is also echoed from the MAC-PHY back to the SPI host to identify
+which register read is failed in case of any bus errors. The echoed
+Control read command will have the first 4 bytes of unused value to be
+ignored by the SPI host followed by 4 bytes echoed control header followed
+by register read data. Control read commands can read either a single
+register or multiple consecutive registers. When multiple consecutive
+registers are read, the address is automatically post-incremented by the
+MAC-PHY. Reading any unimplemented or undefined registers shall return
+zero.
+
+Device drivers API
+==================
+
+The include/linux/oa_tc6.h defines the following functions:
+
+.. c:function:: struct oa_tc6 *oa_tc6_init(struct spi_device *spi, \
+                                           struct net_device *netdev)
+
+Initialize OA TC6 lib.
+
+.. c:function:: void oa_tc6_exit(struct oa_tc6 *tc6)
+
+Free allocated OA TC6 lib.
+
+.. c:function:: int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, \
+                                          u32 value)
+
+Write a single register in the MAC-PHY.
+
+.. c:function:: int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, \
+                                           u32 value[], u8 length)
+
+Writing multiple consecutive registers starting from @address in the MAC-PHY.
+Maximum of 128 consecutive registers can be written starting at @address.
+
+.. c:function:: int oa_tc6_read_register(struct oa_tc6 *tc6, u32 address, \
+                                         u32 *value)
+
+Read a single register in the MAC-PHY.
+
+.. c:function:: int oa_tc6_read_registers(struct oa_tc6 *tc6, u32 address, \
+                                          u32 value[], u8 length)
+
+Reading multiple consecutive registers starting from @address in the MAC-PHY.
+Maximum of 128 consecutive registers can be read starting at @address.
+
+.. c:function:: netdev_tx_t oa_tc6_start_xmit(struct oa_tc6 *tc6, \
+                                              struct sk_buff *skb);
+
+The transmit Ethernet frame in the skb is or going to be transmitted through
+the MAC-PHY.
+
+.. c:function:: int oa_tc6_zero_align_receive_frame_enable(struct oa_tc6 *tc6);
+
+Zero align receive frame feature can be enabled to align all receive ethernet
+frames data to start at the beginning of any receive data chunk payload with a
+start word offset (SWO) of zero.

@@ -17059,6 +17059,12 @@ L:	linux-rdma@vger.kernel.org
 S:	Supported
 F:	drivers/infiniband/ulp/opa_vnic
 
+OPEN ALLIANCE 10BASE-T1S MACPHY SERIAL INTERFACE FRAMEWORK
+M:	Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	Documentation/networking/oa-tc6-framework.rst
+
 OPEN FIRMWARE AND FLATTENED DEVICE TREE
 M:	Rob Herring <robh@kernel.org>
 M:	Saravana Kannan <saravanak@google.com>

@@ -17064,6 +17064,8 @@ M:	Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
 F:	Documentation/networking/oa-tc6-framework.rst
+F:	drivers/include/linux/oa_tc6.h
+F:	drivers/net/ethernet/oa_tc6.c
 
 OPEN FIRMWARE AND FLATTENED DEVICE TREE
 M:	Rob Herring <robh@kernel.org>

@@ -158,6 +158,17 @@ config ETHOC
 	help
 	  Say Y here if you want to use the OpenCores 10/100 Mbps Ethernet MAC.
 
+config OA_TC6
+	tristate "OPEN Alliance TC6 10BASE-T1x MAC-PHY support"
+	depends on SPI
+	select PHYLIB
+	help
+	  This library implements OPEN Alliance TC6 10BASE-T1x MAC-PHY
+	  Serial Interface protocol for supporting 10BASE-T1x MAC-PHYs.
+
+	  To know the implementation details, refer documentation in
+	  <file:Documentation/networking/oa-tc6-framework.rst>.
+
 source "drivers/net/ethernet/packetengines/Kconfig"
 source "drivers/net/ethernet/pasemi/Kconfig"
 source "drivers/net/ethernet/pensando/Kconfig"

@@ -105,3 +105,4 @@ obj-$(CONFIG_NET_VENDOR_XILINX) += xilinx/
 obj-$(CONFIG_NET_VENDOR_XIRCOM) += xircom/
 obj-$(CONFIG_NET_VENDOR_SYNOPSYS) += synopsys/
 obj-$(CONFIG_NET_VENDOR_PENSANDO) += pensando/
+obj-$(CONFIG_OA_TC6) += oa_tc6.o

@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface framework
+ *
+ * Author: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/oa_tc6.h>
+
+/* Control command header */
+#define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)
+#define OA_TC6_CTRL_HEADER_WRITE_NOT_READ	BIT(29)
+#define OA_TC6_CTRL_HEADER_MEM_MAP_SELECTOR	GENMASK(27, 24)
+#define OA_TC6_CTRL_HEADER_ADDR			GENMASK(23, 8)
+#define OA_TC6_CTRL_HEADER_LENGTH		GENMASK(7, 1)
+#define OA_TC6_CTRL_HEADER_PARITY		BIT(0)
+
+#define OA_TC6_CTRL_HEADER_SIZE			4
+#define OA_TC6_CTRL_REG_VALUE_SIZE		4
+#define OA_TC6_CTRL_IGNORED_SIZE		4
+#define OA_TC6_CTRL_MAX_REGISTERS		128
+#define OA_TC6_CTRL_SPI_BUF_SIZE		(OA_TC6_CTRL_HEADER_SIZE +\
+						(OA_TC6_CTRL_MAX_REGISTERS *\
+						OA_TC6_CTRL_REG_VALUE_SIZE) +\
+						OA_TC6_CTRL_IGNORED_SIZE)
+
+/* Internal structure for MAC-PHY drivers */
+struct oa_tc6 {
+	struct spi_device *spi;
+	struct mutex spi_ctrl_lock; /* Protects spi control transfer */
+	void *spi_ctrl_tx_buf;
+	void *spi_ctrl_rx_buf;
+};
+
+enum oa_tc6_header_type {
+	OA_TC6_CTRL_HEADER,
+};
+
+enum oa_tc6_register_op {
+	OA_TC6_CTRL_REG_WRITE = 1,
+};
+
+static int oa_tc6_spi_transfer(struct oa_tc6 *tc6,
+			       enum oa_tc6_header_type header_type, u16 length)
+{
+	struct spi_transfer xfer = { 0 };
+	struct spi_message msg;
+
+	xfer.tx_buf = tc6->spi_ctrl_tx_buf;
+	xfer.rx_buf = tc6->spi_ctrl_rx_buf;
+	xfer.len = length;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	return spi_sync(tc6->spi, &msg);
+}
+
+static int oa_tc6_get_parity(u32 p)
+{
+	/* Public domain code snippet, lifted from
+	 * http://www-graphics.stanford.edu/~seander/bithacks.html
+	 */
+	p ^= p >> 1;
+	p ^= p >> 2;
+	p = (p & 0x11111111U) * 0x11111111U;
+
+	/* Odd parity is used here */
+	return !((p >> 28) & 1);
+}
+
+static __be32 oa_tc6_prepare_ctrl_header(u32 addr, u8 length,
+					 enum oa_tc6_register_op reg_op)
+{
+	u32 header;
+
+	header = FIELD_PREP(OA_TC6_CTRL_HEADER_DATA_NOT_CTRL,
+			    OA_TC6_CTRL_HEADER) |
+		 FIELD_PREP(OA_TC6_CTRL_HEADER_WRITE_NOT_READ, reg_op) |
+		 FIELD_PREP(OA_TC6_CTRL_HEADER_MEM_MAP_SELECTOR, addr >> 16) |
+		 FIELD_PREP(OA_TC6_CTRL_HEADER_ADDR, addr) |
+		 FIELD_PREP(OA_TC6_CTRL_HEADER_LENGTH, length - 1);
+	header |= FIELD_PREP(OA_TC6_CTRL_HEADER_PARITY,
+			     oa_tc6_get_parity(header));
+
+	return cpu_to_be32(header);
+}
+
+static void oa_tc6_update_ctrl_write_data(struct oa_tc6 *tc6, u32 value[],
+					  u8 length)
+{
+	__be32 *tx_buf = tc6->spi_ctrl_tx_buf + OA_TC6_CTRL_HEADER_SIZE;
+
+	for (int i = 0; i < length; i++)
+		*tx_buf++ = cpu_to_be32(value[i]);
+}
+
+static u16 oa_tc6_calculate_ctrl_buf_size(u8 length)
+{
+	/* Control command consists 4 bytes header + 4 bytes register value for
+	 * each register + 4 bytes ignored value.
+	 */
+	return OA_TC6_CTRL_HEADER_SIZE + OA_TC6_CTRL_REG_VALUE_SIZE * length +
+	       OA_TC6_CTRL_IGNORED_SIZE;
+}
+
+static void oa_tc6_prepare_ctrl_spi_buf(struct oa_tc6 *tc6, u32 address,
+					u32 value[], u8 length,
+					enum oa_tc6_register_op reg_op)
+{
+	__be32 *tx_buf = tc6->spi_ctrl_tx_buf;
+
+	*tx_buf = oa_tc6_prepare_ctrl_header(address, length, reg_op);
+
+	oa_tc6_update_ctrl_write_data(tc6, value, length);
+}
+
+static int oa_tc6_check_ctrl_write_reply(struct oa_tc6 *tc6, u8 size)
+{
+	u8 *tx_buf = tc6->spi_ctrl_tx_buf;
+	u8 *rx_buf = tc6->spi_ctrl_rx_buf;
+
+	rx_buf += OA_TC6_CTRL_IGNORED_SIZE;
+
+	/* The echoed control write must match with the one that was
+	 * transmitted.
+	 */
+	if (memcmp(tx_buf, rx_buf, size - OA_TC6_CTRL_IGNORED_SIZE))
+		return -EPROTO;
+
+	return 0;
+}
+
+static int oa_tc6_perform_ctrl(struct oa_tc6 *tc6, u32 address, u32 value[],
+			       u8 length, enum oa_tc6_register_op reg_op)
+{
+	u16 size;
+	int ret;
+
+	/* Prepare control command and copy to SPI control buffer */
+	oa_tc6_prepare_ctrl_spi_buf(tc6, address, value, length, reg_op);
+
+	size = oa_tc6_calculate_ctrl_buf_size(length);
+
+	/* Perform SPI transfer */
+	ret = oa_tc6_spi_transfer(tc6, OA_TC6_CTRL_HEADER, size);
+	if (ret) {
+		dev_err(&tc6->spi->dev, "SPI transfer failed for control: %d\n",
+			ret);
+		return ret;
+	}
+
+	/* Check echoed/received control write command reply for errors */
+	return oa_tc6_check_ctrl_write_reply(tc6, size);
+}
+
+/**
+ * oa_tc6_write_registers - function for writing multiple consecutive registers.
+ * @tc6: oa_tc6 struct.
+ * @address: address of the first register to be written in the MAC-PHY.
+ * @value: values to be written from the starting register address @address.
+ * @length: number of consecutive registers to be written from @address.
+ *
+ * Maximum of 128 consecutive registers can be written starting at @address.
+ *
+ * Return: 0 on success otherwise failed.
+ */
+int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
+			   u8 length)
+{
+	int ret;
+
+	if (!length || length > OA_TC6_CTRL_MAX_REGISTERS) {
+		dev_err(&tc6->spi->dev, "Invalid register length parameter\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&tc6->spi_ctrl_lock);
+	ret = oa_tc6_perform_ctrl(tc6, address, value, length,
+				  OA_TC6_CTRL_REG_WRITE);
+	mutex_unlock(&tc6->spi_ctrl_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(oa_tc6_write_registers);
+
+/**
+ * oa_tc6_write_register - function for writing a MAC-PHY register.
+ * @tc6: oa_tc6 struct.
+ * @address: register address of the MAC-PHY to be written.
+ * @value: value to be written in the @address register address of the MAC-PHY.
+ *
+ * Return: 0 on success otherwise failed.
+ */
+int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value)
+{
+	return oa_tc6_write_registers(tc6, address, &value, 1);
+}
+EXPORT_SYMBOL_GPL(oa_tc6_write_register);
+
+/**
+ * oa_tc6_init - allocates and initializes oa_tc6 structure.
+ * @spi: device with which data will be exchanged.
+ *
+ * Return: pointer reference to the oa_tc6 structure if the MAC-PHY
+ * initialization is successful otherwise NULL.
+ */
+struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
+{
+	struct oa_tc6 *tc6;
+
+	tc6 = devm_kzalloc(&spi->dev, sizeof(*tc6), GFP_KERNEL);
+	if (!tc6)
+		return NULL;
+
+	tc6->spi = spi;
+	mutex_init(&tc6->spi_ctrl_lock);
+
+	/* Set the SPI controller to pump at realtime priority */
+	tc6->spi->rt = true;
+	spi_setup(tc6->spi);
+
+	tc6->spi_ctrl_tx_buf = devm_kzalloc(&tc6->spi->dev,
+					    OA_TC6_CTRL_SPI_BUF_SIZE,
+					    GFP_KERNEL);
+	if (!tc6->spi_ctrl_tx_buf)
+		return NULL;
+
+	tc6->spi_ctrl_rx_buf = devm_kzalloc(&tc6->spi->dev,
+					    OA_TC6_CTRL_SPI_BUF_SIZE,
+					    GFP_KERNEL);
+	if (!tc6->spi_ctrl_rx_buf)
+		return NULL;
+
+	return tc6;
+}
+EXPORT_SYMBOL_GPL(oa_tc6_init);
+
+MODULE_DESCRIPTION("OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface Lib");
+MODULE_AUTHOR("Parthiban Veerasooran <parthiban.veerasooran@microchip.com>");
+MODULE_LICENSE("GPL");

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface framework
+ *
+ * Link: https://opensig.org/download/document/OPEN_Alliance_10BASET1x_MAC-PHY_Serial_Interface_V1.1.pdf
+ *
+ * Author: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
+ */
+
+#include <linux/spi/spi.h>
+
+struct oa_tc6;
+
+struct oa_tc6 *oa_tc6_init(struct spi_device *spi);
+int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value);
+int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
+			   u8 length);

@@ -38,6 +38,7 @@ enum oa_tc6_header_type {
 };
 
 enum oa_tc6_register_op {
+	OA_TC6_CTRL_REG_READ = 0,
 	OA_TC6_CTRL_REG_WRITE = 1,
 };
 

@@ -113,7 +114,8 @@ static void oa_tc6_prepare_ctrl_spi_buf(struct oa_tc6 *tc6, u32 address,
 
 	*tx_buf = oa_tc6_prepare_ctrl_header(address, length, reg_op);
 
-	oa_tc6_update_ctrl_write_data(tc6, value, length);
+	if (reg_op == OA_TC6_CTRL_REG_WRITE)
+		oa_tc6_update_ctrl_write_data(tc6, value, length);
 }
 
 static int oa_tc6_check_ctrl_write_reply(struct oa_tc6 *tc6, u8 size)

@@ -132,6 +134,30 @@ static int oa_tc6_check_ctrl_write_reply(struct oa_tc6 *tc6, u8 size)
 	return 0;
 }
 
+static int oa_tc6_check_ctrl_read_reply(struct oa_tc6 *tc6, u8 size)
+{
+	u32 *rx_buf = tc6->spi_ctrl_rx_buf + OA_TC6_CTRL_IGNORED_SIZE;
+	u32 *tx_buf = tc6->spi_ctrl_tx_buf;
+
+	/* The echoed control read header must match with the one that was
+	 * transmitted.
+	 */
+	if (*tx_buf != *rx_buf)
+		return -EPROTO;
+
+	return 0;
+}
+
+static void oa_tc6_copy_ctrl_read_data(struct oa_tc6 *tc6, u32 value[],
+				       u8 length)
+{
+	__be32 *rx_buf = tc6->spi_ctrl_rx_buf + OA_TC6_CTRL_IGNORED_SIZE +
+			 OA_TC6_CTRL_HEADER_SIZE;
+
+	for (int i = 0; i < length; i++)
+		value[i] = be32_to_cpu(*rx_buf++);
+}
+
 static int oa_tc6_perform_ctrl(struct oa_tc6 *tc6, u32 address, u32 value[],
 			       u8 length, enum oa_tc6_register_op reg_op)
 {

@@ -152,8 +178,62 @@ static int oa_tc6_perform_ctrl(struct oa_tc6 *tc6, u32 address, u32 value[],
 	}
 
 	/* Check echoed/received control write command reply for errors */
-	return oa_tc6_check_ctrl_write_reply(tc6, size);
+	if (reg_op == OA_TC6_CTRL_REG_WRITE)
+		return oa_tc6_check_ctrl_write_reply(tc6, size);
+
+	/* Check echoed/received control read command reply for errors */
+	ret = oa_tc6_check_ctrl_read_reply(tc6, size);
+	if (ret)
+		return ret;
+
+	oa_tc6_copy_ctrl_read_data(tc6, value, length);
+
+	return 0;
+}
+
+/**
+ * oa_tc6_read_registers - function for reading multiple consecutive registers.
+ * @tc6: oa_tc6 struct.
+ * @address: address of the first register to be read in the MAC-PHY.
+ * @value: values to be read from the starting register address @address.
+ * @length: number of consecutive registers to be read from @address.
+ *
+ * Maximum of 128 consecutive registers can be read starting at @address.
+ *
+ * Return: 0 on success otherwise failed.
+ */
+int oa_tc6_read_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
+			  u8 length)
+{
+	int ret;
+
+	if (!length || length > OA_TC6_CTRL_MAX_REGISTERS) {
+		dev_err(&tc6->spi->dev, "Invalid register length parameter\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&tc6->spi_ctrl_lock);
+	ret = oa_tc6_perform_ctrl(tc6, address, value, length,
+				  OA_TC6_CTRL_REG_READ);
+	mutex_unlock(&tc6->spi_ctrl_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(oa_tc6_read_registers);
+
+/**
+ * oa_tc6_read_register - function for reading a MAC-PHY register.
+ * @tc6: oa_tc6 struct.
+ * @address: register address of the MAC-PHY to be read.
+ * @value: value read from the @address register address of the MAC-PHY.
+ *
+ * Return: 0 on success otherwise failed.
+ */
+int oa_tc6_read_register(struct oa_tc6 *tc6, u32 address, u32 *value)
+{
+	return oa_tc6_read_registers(tc6, address, value, 1);
 }
+EXPORT_SYMBOL_GPL(oa_tc6_read_register);
 
 /**
  * oa_tc6_write_registers - function for writing multiple consecutive registers.

@@ -15,3 +15,6 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi);
 int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value);
 int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
 			   u8 length);
+int oa_tc6_read_register(struct oa_tc6 *tc6, u32 address, u32 *value);
+int oa_tc6_read_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
+			  u8 length);

@@ -18,6 +18,13 @@
 #define OA_TC6_REG_STATUS0			0x0008
 #define STATUS0_RESETC				BIT(6)	/* Reset Complete */
 
+/* Interrupt Mask Register #0 */
+#define OA_TC6_REG_INT_MASK0			0x000C
+#define INT_MASK0_HEADER_ERR_MASK		BIT(5)
+#define INT_MASK0_LOSS_OF_FRAME_ERR_MASK	BIT(4)
+#define INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK	BIT(3)
+#define INT_MASK0_TX_PROTOCOL_ERR_MASK		BIT(0)
+
 /* Control command header */
 #define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)
 #define OA_TC6_CTRL_HEADER_WRITE_NOT_READ	BIT(29)

@@ -327,6 +334,23 @@ static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)
 	return oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, regval);
 }
 
+static int oa_tc6_unmask_macphy_error_interrupts(struct oa_tc6 *tc6)
+{
+	u32 regval;
+	int ret;
+
+	ret = oa_tc6_read_register(tc6, OA_TC6_REG_INT_MASK0, &regval);
+	if (ret)
+		return ret;
+
+	regval &= ~(INT_MASK0_TX_PROTOCOL_ERR_MASK |
+		    INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK |
+		    INT_MASK0_LOSS_OF_FRAME_ERR_MASK |
+		    INT_MASK0_HEADER_ERR_MASK);
+
+	return oa_tc6_write_register(tc6, OA_TC6_REG_INT_MASK0, regval);
+}
+
 /**
  * oa_tc6_init - allocates and initializes oa_tc6 structure.
  * @spi: device with which data will be exchanged.

@@ -369,6 +393,13 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
 		return NULL;
 	}
 
+	ret = oa_tc6_unmask_macphy_error_interrupts(tc6);
+	if (ret) {
+		dev_err(&tc6->spi->dev,
+			"MAC-PHY error interrupts unmask failed: %d\n", ret);
+		return NULL;
+	}
+
 	return tc6;
 }
 EXPORT_SYMBOL_GPL(oa_tc6_init);

@@ -6,8 +6,18 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/iopoll.h>
 #include <linux/oa_tc6.h>
 
+/* OPEN Alliance TC6 registers */
+/* Reset Control and Status Register */
+#define OA_TC6_REG_RESET			0x0003
+#define RESET_SWRESET				BIT(0)	/* Software Reset */
+
+/* Status Register #0 */
+#define OA_TC6_REG_STATUS0			0x0008
+#define STATUS0_RESETC				BIT(6)	/* Reset Complete */
+
 /* Control command header */
 #define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)
 #define OA_TC6_CTRL_HEADER_WRITE_NOT_READ	BIT(29)

@@ -24,6 +34,8 @@
 						(OA_TC6_CTRL_MAX_REGISTERS *\
 						OA_TC6_CTRL_REG_VALUE_SIZE) +\
 						OA_TC6_CTRL_IGNORED_SIZE)
+#define STATUS0_RESETC_POLL_DELAY		1000
+#define STATUS0_RESETC_POLL_TIMEOUT		1000000
 
 /* Internal structure for MAC-PHY drivers */
 struct oa_tc6 {

@@ -279,6 +291,42 @@ int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value)
 }
 EXPORT_SYMBOL_GPL(oa_tc6_write_register);
 
+static int oa_tc6_read_status0(struct oa_tc6 *tc6)
+{
+	u32 regval;
+	int ret;
+
+	ret = oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, &regval);
+	if (ret) {
+		dev_err(&tc6->spi->dev, "STATUS0 register read failed: %d\n",
+			ret);
+		return 0;
+	}
+
+	return regval;
+}
+
+static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)
+{
+	u32 regval = RESET_SWRESET;
+	int ret;
+
+	ret = oa_tc6_write_register(tc6, OA_TC6_REG_RESET, regval);
+	if (ret)
+		return ret;
+
+	/* Poll for soft reset complete for every 1ms until 1s timeout */
+	ret = readx_poll_timeout(oa_tc6_read_status0, tc6, regval,
+				 regval & STATUS0_RESETC,
+				 STATUS0_RESETC_POLL_DELAY,
+				 STATUS0_RESETC_POLL_TIMEOUT);
+	if (ret)
+		return -ENODEV;
+
+	/* Clear the reset complete status */
+	return oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, regval);
+}
+
 /**
  * oa_tc6_init - allocates and initializes oa_tc6 structure.
  * @spi: device with which data will be exchanged.

@@ -289,6 +337,7 @@ EXPORT_SYMBOL_GPL(oa_tc6_write_register);
 struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
 {
 	struct oa_tc6 *tc6;
+	int ret;
 
 	tc6 = devm_kzalloc(&spi->dev, sizeof(*tc6), GFP_KERNEL);
 	if (!tc6)

@@ -313,6 +362,13 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
 	if (!tc6->spi_ctrl_rx_buf)
 		return NULL;
 
+	ret = oa_tc6_sw_reset_macphy(tc6);
+	if (ret) {
+		dev_err(&tc6->spi->dev,
+			"MAC-PHY software reset failed: %d\n", ret);
+		return NULL;
+	}
+
 	return tc6;
 }
 EXPORT_SYMBOL_GPL(oa_tc6_init);

@@ -7,9 +7,15 @@
 
 #include <linux/bitfield.h>
 #include <linux/iopoll.h>
+#include <linux/mdio.h>
+#include <linux/phy.h>
 #include <linux/oa_tc6.h>
 
 /* OPEN Alliance TC6 registers */
+/* Standard Capabilities Register */
+#define OA_TC6_REG_STDCAP			0x0002
+#define STDCAP_DIRECT_PHY_REG_ACCESS		BIT(8)
+
 /* Reset Control and Status Register */
 #define OA_TC6_REG_RESET			0x0003
 #define RESET_SWRESET				BIT(0)	/* Software Reset */

@@ -25,6 +31,10 @@
 #define INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK	BIT(3)
 #define INT_MASK0_TX_PROTOCOL_ERR_MASK		BIT(0)
 
+/* PHY Clause 22 registers base address and mask */
+#define OA_TC6_PHY_STD_REG_ADDR_BASE		0xFF00
+#define OA_TC6_PHY_STD_REG_ADDR_MASK		0x1F
+
 /* Control command header */
 #define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)
 #define OA_TC6_CTRL_HEADER_WRITE_NOT_READ	BIT(29)

@@ -33,6 +43,15 @@
 #define OA_TC6_CTRL_HEADER_LENGTH		GENMASK(7, 1)
 #define OA_TC6_CTRL_HEADER_PARITY		BIT(0)
 
+/* PHY – Clause 45 registers memory map selector (MMS) as per table 6 in the
+ * OPEN Alliance specification.
+ */
+#define OA_TC6_PHY_C45_PCS_MMS2			2	/* MMD 3 */
+#define OA_TC6_PHY_C45_PMA_PMD_MMS3		3	/* MMD 1 */
+#define OA_TC6_PHY_C45_VS_PLCA_MMS4		4	/* MMD 31 */
+#define OA_TC6_PHY_C45_AUTO_NEG_MMS5		5	/* MMD 7 */
+#define OA_TC6_PHY_C45_POWER_UNIT_MMS6		6	/* MMD 13 */
+
 #define OA_TC6_CTRL_HEADER_SIZE			4
 #define OA_TC6_CTRL_REG_VALUE_SIZE		4
 #define OA_TC6_CTRL_IGNORED_SIZE		4

@@ -46,6 +65,10 @@
 
 /* Internal structure for MAC-PHY drivers */
 struct oa_tc6 {
+	struct device *dev;
+	struct net_device *netdev;
+	struct phy_device *phydev;
+	struct mii_bus *mdiobus;
 	struct spi_device *spi;
 	struct mutex spi_ctrl_lock; /* Protects spi control transfer */
 	void *spi_ctrl_tx_buf;

@@ -298,6 +321,191 @@ int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value)
 }
 EXPORT_SYMBOL_GPL(oa_tc6_write_register);
 
+static int oa_tc6_check_phy_reg_direct_access_capability(struct oa_tc6 *tc6)
+{
+	u32 regval;
+	int ret;
+
+	ret = oa_tc6_read_register(tc6, OA_TC6_REG_STDCAP, &regval);
+	if (ret)
+		return ret;
+
+	if (!(regval & STDCAP_DIRECT_PHY_REG_ACCESS))
+		return -ENODEV;
+
+	return 0;
+}
+
+static void oa_tc6_handle_link_change(struct net_device *netdev)
+{
+	phy_print_status(netdev->phydev);
+}
+
+static int oa_tc6_mdiobus_read(struct mii_bus *bus, int addr, int regnum)
+{
+	struct oa_tc6 *tc6 = bus->priv;
+	u32 regval;
+	bool ret;
+
+	ret = oa_tc6_read_register(tc6, OA_TC6_PHY_STD_REG_ADDR_BASE |
+				   (regnum & OA_TC6_PHY_STD_REG_ADDR_MASK),
+				   &regval);
+	if (ret)
+		return ret;
+
+	return regval;
+}
+
+static int oa_tc6_mdiobus_write(struct mii_bus *bus, int addr, int regnum,
+				u16 val)
+{
+	struct oa_tc6 *tc6 = bus->priv;
+
+	return oa_tc6_write_register(tc6, OA_TC6_PHY_STD_REG_ADDR_BASE |
+				     (regnum & OA_TC6_PHY_STD_REG_ADDR_MASK),
+				     val);
+}
+
+static int oa_tc6_get_phy_c45_mms(int devnum)
+{
+	switch (devnum) {
+	case MDIO_MMD_PCS:
+		return OA_TC6_PHY_C45_PCS_MMS2;
+	case MDIO_MMD_PMAPMD:
+		return OA_TC6_PHY_C45_PMA_PMD_MMS3;
+	case MDIO_MMD_VEND2:
+		return OA_TC6_PHY_C45_VS_PLCA_MMS4;
+	case MDIO_MMD_AN:
+		return OA_TC6_PHY_C45_AUTO_NEG_MMS5;
+	case MDIO_MMD_POWER_UNIT:
+		return OA_TC6_PHY_C45_POWER_UNIT_MMS6;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int oa_tc6_mdiobus_read_c45(struct mii_bus *bus, int addr, int devnum,
+				   int regnum)
+{
+	struct oa_tc6 *tc6 = bus->priv;
+	u32 regval;
+	int ret;
+
+	ret = oa_tc6_get_phy_c45_mms(devnum);
+	if (ret < 0)
+		return ret;
+
+	ret = oa_tc6_read_register(tc6, (ret << 16) | regnum, &regval);
+	if (ret)
+		return ret;
+
+	return regval;
+}
+
+static int oa_tc6_mdiobus_write_c45(struct mii_bus *bus, int addr, int devnum,
+				    int regnum, u16 val)
+{
+	struct oa_tc6 *tc6 = bus->priv;
+	int ret;
+
+	ret = oa_tc6_get_phy_c45_mms(devnum);
+	if (ret < 0)
+		return ret;
+
+	return oa_tc6_write_register(tc6, (ret << 16) | regnum, val);
+}
+
+static int oa_tc6_mdiobus_register(struct oa_tc6 *tc6)
+{
+	int ret;
+
+	tc6->mdiobus = mdiobus_alloc();
+	if (!tc6->mdiobus) {
+		netdev_err(tc6->netdev, "MDIO bus alloc failed\n");
+		return -ENOMEM;
+	}
+
+	tc6->mdiobus->priv = tc6;
+	tc6->mdiobus->read = oa_tc6_mdiobus_read;
+	tc6->mdiobus->write = oa_tc6_mdiobus_write;
+	/* OPEN Alliance 10BASE-T1x compliance MAC-PHYs will have both C22 and
+	 * C45 registers space. If the PHY is discovered via C22 bus protocol it
+	 * assumes it uses C22 protocol and always uses C22 registers indirect
+	 * access to access C45 registers. This is because, we don't have a
+	 * clean separation between C22/C45 register space and C22/C45 MDIO bus
+	 * protocols. Resulting, PHY C45 registers direct access can't be used
+	 * which can save multiple SPI bus access. To support this feature, PHY
+	 * drivers can set .read_mmd/.write_mmd in the PHY driver to call
+	 * .read_c45/.write_c45. Ex: drivers/net/phy/microchip_t1s.c
+	 */
+	tc6->mdiobus->read_c45 = oa_tc6_mdiobus_read_c45;
+	tc6->mdiobus->write_c45 = oa_tc6_mdiobus_write_c45;
+	tc6->mdiobus->name = "oa-tc6-mdiobus";
+	tc6->mdiobus->parent = tc6->dev;
+
+	snprintf(tc6->mdiobus->id, ARRAY_SIZE(tc6->mdiobus->id), "%s",
+		 dev_name(&tc6->spi->dev));
+
+	ret = mdiobus_register(tc6->mdiobus);
+	if (ret) {
+		netdev_err(tc6->netdev, "Could not register MDIO bus\n");
+		mdiobus_free(tc6->mdiobus);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void oa_tc6_mdiobus_unregister(struct oa_tc6 *tc6)
+{
+	mdiobus_unregister(tc6->mdiobus);
+	mdiobus_free(tc6->mdiobus);
+}
+
+static int oa_tc6_phy_init(struct oa_tc6 *tc6)
+{
+	int ret;
+
+	ret = oa_tc6_check_phy_reg_direct_access_capability(tc6);
+	if (ret) {
+		netdev_err(tc6->netdev,
+			   "Direct PHY register access is not supported by the MAC-PHY\n");
+		return ret;
+	}
+
+	ret = oa_tc6_mdiobus_register(tc6);
+	if (ret)
+		return ret;
+
+	tc6->phydev = phy_find_first(tc6->mdiobus);
+	if (!tc6->phydev) {
+		netdev_err(tc6->netdev, "No PHY found\n");
+		oa_tc6_mdiobus_unregister(tc6);
+		return -ENODEV;
+	}
+
+	tc6->phydev->is_internal = true;
+	ret = phy_connect_direct(tc6->netdev, tc6->phydev,
+				 &oa_tc6_handle_link_change,
+				 PHY_INTERFACE_MODE_INTERNAL);
+	if (ret) {
+		netdev_err(tc6->netdev, "Can't attach PHY to %s\n",
+			   tc6->mdiobus->id);
+		oa_tc6_mdiobus_unregister(tc6);
+		return ret;
+	}
+
+	phy_attached_info(tc6->netdev->phydev);
+
+	return 0;
+}
+
+static void oa_tc6_phy_exit(struct oa_tc6 *tc6)
+{
+	phy_disconnect(tc6->phydev);
+	oa_tc6_mdiobus_unregister(tc6);
+}
+
 static int oa_tc6_read_status0(struct oa_tc6 *tc6)
 {
 	u32 regval;

@@ -354,11 +562,12 @@ static int oa_tc6_unmask_macphy_error_interrupts(struct oa_tc6 *tc6)
 /**
  * oa_tc6_init - allocates and initializes oa_tc6 structure.
  * @spi: device with which data will be exchanged.
+ * @netdev: network device interface structure.
  *
  * Return: pointer reference to the oa_tc6 structure if the MAC-PHY
  * initialization is successful otherwise NULL.
  */
-struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
+struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev)
 {
 	struct oa_tc6 *tc6;
 	int ret;

@@ -368,6 +577,8 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
 		return NULL;
 
 	tc6->spi = spi;
+	tc6->netdev = netdev;
+	SET_NETDEV_DEV(netdev, &spi->dev);
 	mutex_init(&tc6->spi_ctrl_lock);
 
 	/* Set the SPI controller to pump at realtime priority */

@@ -400,10 +611,27 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
 		return NULL;
 	}
 
+	ret = oa_tc6_phy_init(tc6);
+	if (ret) {
+		dev_err(&tc6->spi->dev,
+			"MAC internal PHY initialization failed: %d\n", ret);
+		return NULL;
+	}
+
 	return tc6;
 }
 EXPORT_SYMBOL_GPL(oa_tc6_init);
 
+/**
+ * oa_tc6_exit - exit function.
+ * @tc6: oa_tc6 struct.
+ */
+void oa_tc6_exit(struct oa_tc6 *tc6)
+{
+	oa_tc6_phy_exit(tc6);
+}
+EXPORT_SYMBOL_GPL(oa_tc6_exit);
+
 MODULE_DESCRIPTION("OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface Lib");
 MODULE_AUTHOR("Parthiban Veerasooran <parthiban.veerasooran@microchip.com>");
 MODULE_LICENSE("GPL");

@@ -7,11 +7,13 @@
  * Author: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
  */
 
+#include <linux/etherdevice.h>
 #include <linux/spi/spi.h>
 
 struct oa_tc6;
 
-struct oa_tc6 *oa_tc6_init(struct spi_device *spi);
+struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev);
+void oa_tc6_exit(struct oa_tc6 *tc6);
 int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value);
 int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, u32 value[],
 			   u8 length);