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1// SPDX-License-Identifier: GPL-2.0+2/*3 * OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface framework4 *5 * Author: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>6 */7 8#include <linux/bitfield.h>9#include <linux/iopoll.h>10#include <linux/mdio.h>11#include <linux/phy.h>12#include <linux/oa_tc6.h>13 14/* OPEN Alliance TC6 registers */15/* Standard Capabilities Register */16#define OA_TC6_REG_STDCAP			0x000217#define STDCAP_DIRECT_PHY_REG_ACCESS		BIT(8)18 19/* Reset Control and Status Register */20#define OA_TC6_REG_RESET			0x000321#define RESET_SWRESET				BIT(0)	/* Software Reset */22 23/* Configuration Register #0 */24#define OA_TC6_REG_CONFIG0			0x000425#define CONFIG0_SYNC				BIT(15)26#define CONFIG0_ZARFE_ENABLE			BIT(12)27 28/* Status Register #0 */29#define OA_TC6_REG_STATUS0			0x000830#define STATUS0_RESETC				BIT(6)	/* Reset Complete */31#define STATUS0_HEADER_ERROR			BIT(5)32#define STATUS0_LOSS_OF_FRAME_ERROR		BIT(4)33#define STATUS0_RX_BUFFER_OVERFLOW_ERROR	BIT(3)34#define STATUS0_TX_PROTOCOL_ERROR		BIT(0)35 36/* Buffer Status Register */37#define OA_TC6_REG_BUFFER_STATUS		0x000B38#define BUFFER_STATUS_TX_CREDITS_AVAILABLE	GENMASK(15, 8)39#define BUFFER_STATUS_RX_CHUNKS_AVAILABLE	GENMASK(7, 0)40 41/* Interrupt Mask Register #0 */42#define OA_TC6_REG_INT_MASK0			0x000C43#define INT_MASK0_HEADER_ERR_MASK		BIT(5)44#define INT_MASK0_LOSS_OF_FRAME_ERR_MASK	BIT(4)45#define INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK	BIT(3)46#define INT_MASK0_TX_PROTOCOL_ERR_MASK		BIT(0)47 48/* PHY Clause 22 registers base address and mask */49#define OA_TC6_PHY_STD_REG_ADDR_BASE		0xFF0050#define OA_TC6_PHY_STD_REG_ADDR_MASK		0x1F51 52/* Control command header */53#define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)54#define OA_TC6_CTRL_HEADER_WRITE_NOT_READ	BIT(29)55#define OA_TC6_CTRL_HEADER_MEM_MAP_SELECTOR	GENMASK(27, 24)56#define OA_TC6_CTRL_HEADER_ADDR			GENMASK(23, 8)57#define OA_TC6_CTRL_HEADER_LENGTH		GENMASK(7, 1)58#define OA_TC6_CTRL_HEADER_PARITY		BIT(0)59 60/* Data header */61#define OA_TC6_DATA_HEADER_DATA_NOT_CTRL	BIT(31)62#define OA_TC6_DATA_HEADER_DATA_VALID		BIT(21)63#define OA_TC6_DATA_HEADER_START_VALID		BIT(20)64#define OA_TC6_DATA_HEADER_START_WORD_OFFSET	GENMASK(19, 16)65#define OA_TC6_DATA_HEADER_END_VALID		BIT(14)66#define OA_TC6_DATA_HEADER_END_BYTE_OFFSET	GENMASK(13, 8)67#define OA_TC6_DATA_HEADER_PARITY		BIT(0)68 69/* Data footer */70#define OA_TC6_DATA_FOOTER_EXTENDED_STS		BIT(31)71#define OA_TC6_DATA_FOOTER_RXD_HEADER_BAD	BIT(30)72#define OA_TC6_DATA_FOOTER_CONFIG_SYNC		BIT(29)73#define OA_TC6_DATA_FOOTER_RX_CHUNKS		GENMASK(28, 24)74#define OA_TC6_DATA_FOOTER_DATA_VALID		BIT(21)75#define OA_TC6_DATA_FOOTER_START_VALID		BIT(20)76#define OA_TC6_DATA_FOOTER_START_WORD_OFFSET	GENMASK(19, 16)77#define OA_TC6_DATA_FOOTER_END_VALID		BIT(14)78#define OA_TC6_DATA_FOOTER_END_BYTE_OFFSET	GENMASK(13, 8)79#define OA_TC6_DATA_FOOTER_TX_CREDITS		GENMASK(5, 1)80 81/* PHY – Clause 45 registers memory map selector (MMS) as per table 6 in the82 * OPEN Alliance specification.83 */84#define OA_TC6_PHY_C45_PCS_MMS2			2	/* MMD 3 */85#define OA_TC6_PHY_C45_PMA_PMD_MMS3		3	/* MMD 1 */86#define OA_TC6_PHY_C45_VS_PLCA_MMS4		4	/* MMD 31 */87#define OA_TC6_PHY_C45_AUTO_NEG_MMS5		5	/* MMD 7 */88#define OA_TC6_PHY_C45_POWER_UNIT_MMS6		6	/* MMD 13 */89 90#define OA_TC6_CTRL_HEADER_SIZE			491#define OA_TC6_CTRL_REG_VALUE_SIZE		492#define OA_TC6_CTRL_IGNORED_SIZE		493#define OA_TC6_CTRL_MAX_REGISTERS		12894#define OA_TC6_CTRL_SPI_BUF_SIZE		(OA_TC6_CTRL_HEADER_SIZE +\95						(OA_TC6_CTRL_MAX_REGISTERS *\96						OA_TC6_CTRL_REG_VALUE_SIZE) +\97						OA_TC6_CTRL_IGNORED_SIZE)98#define OA_TC6_CHUNK_PAYLOAD_SIZE		6499#define OA_TC6_DATA_HEADER_SIZE			4100#define OA_TC6_CHUNK_SIZE			(OA_TC6_DATA_HEADER_SIZE +\101						OA_TC6_CHUNK_PAYLOAD_SIZE)102#define OA_TC6_MAX_TX_CHUNKS			48103#define OA_TC6_SPI_DATA_BUF_SIZE		(OA_TC6_MAX_TX_CHUNKS *\104						OA_TC6_CHUNK_SIZE)105#define STATUS0_RESETC_POLL_DELAY		1000106#define STATUS0_RESETC_POLL_TIMEOUT		1000000107 108/* Internal structure for MAC-PHY drivers */109struct oa_tc6 {110	struct device *dev;111	struct net_device *netdev;112	struct phy_device *phydev;113	struct mii_bus *mdiobus;114	struct spi_device *spi;115	struct mutex spi_ctrl_lock; /* Protects spi control transfer */116	void *spi_ctrl_tx_buf;117	void *spi_ctrl_rx_buf;118	void *spi_data_tx_buf;119	void *spi_data_rx_buf;120	struct sk_buff *ongoing_tx_skb;121	struct sk_buff *waiting_tx_skb;122	struct sk_buff *rx_skb;123	struct task_struct *spi_thread;124	wait_queue_head_t spi_wq;125	u16 tx_skb_offset;126	u16 spi_data_tx_buf_offset;127	u16 tx_credits;128	u8 rx_chunks_available;129	bool rx_buf_overflow;130	bool int_flag;131};132 133enum oa_tc6_header_type {134	OA_TC6_CTRL_HEADER,135	OA_TC6_DATA_HEADER,136};137 138enum oa_tc6_register_op {139	OA_TC6_CTRL_REG_READ = 0,140	OA_TC6_CTRL_REG_WRITE = 1,141};142 143enum oa_tc6_data_valid_info {144	OA_TC6_DATA_INVALID,145	OA_TC6_DATA_VALID,146};147 148enum oa_tc6_data_start_valid_info {149	OA_TC6_DATA_START_INVALID,150	OA_TC6_DATA_START_VALID,151};152 153enum oa_tc6_data_end_valid_info {154	OA_TC6_DATA_END_INVALID,155	OA_TC6_DATA_END_VALID,156};157 158static int oa_tc6_spi_transfer(struct oa_tc6 *tc6,159			       enum oa_tc6_header_type header_type, u16 length)160{161	struct spi_transfer xfer = { 0 };162	struct spi_message msg;163 164	if (header_type == OA_TC6_DATA_HEADER) {165		xfer.tx_buf = tc6->spi_data_tx_buf;166		xfer.rx_buf = tc6->spi_data_rx_buf;167	} else {168		xfer.tx_buf = tc6->spi_ctrl_tx_buf;169		xfer.rx_buf = tc6->spi_ctrl_rx_buf;170	}171	xfer.len = length;172 173	spi_message_init(&msg);174	spi_message_add_tail(&xfer, &msg);175 176	return spi_sync(tc6->spi, &msg);177}178 179static int oa_tc6_get_parity(u32 p)180{181	/* Public domain code snippet, lifted from182	 * http://www-graphics.stanford.edu/~seander/bithacks.html183	 */184	p ^= p >> 1;185	p ^= p >> 2;186	p = (p & 0x11111111U) * 0x11111111U;187 188	/* Odd parity is used here */189	return !((p >> 28) & 1);190}191 192static __be32 oa_tc6_prepare_ctrl_header(u32 addr, u8 length,193					 enum oa_tc6_register_op reg_op)194{195	u32 header;196 197	header = FIELD_PREP(OA_TC6_CTRL_HEADER_DATA_NOT_CTRL,198			    OA_TC6_CTRL_HEADER) |199		 FIELD_PREP(OA_TC6_CTRL_HEADER_WRITE_NOT_READ, reg_op) |200		 FIELD_PREP(OA_TC6_CTRL_HEADER_MEM_MAP_SELECTOR, addr >> 16) |201		 FIELD_PREP(OA_TC6_CTRL_HEADER_ADDR, addr) |202		 FIELD_PREP(OA_TC6_CTRL_HEADER_LENGTH, length - 1);203	header |= FIELD_PREP(OA_TC6_CTRL_HEADER_PARITY,204			     oa_tc6_get_parity(header));205 206	return cpu_to_be32(header);207}208 209static void oa_tc6_update_ctrl_write_data(struct oa_tc6 *tc6, u32 value[],210					  u8 length)211{212	__be32 *tx_buf = tc6->spi_ctrl_tx_buf + OA_TC6_CTRL_HEADER_SIZE;213 214	for (int i = 0; i < length; i++)215		*tx_buf++ = cpu_to_be32(value[i]);216}217 218static u16 oa_tc6_calculate_ctrl_buf_size(u8 length)219{220	/* Control command consists 4 bytes header + 4 bytes register value for221	 * each register + 4 bytes ignored value.222	 */223	return OA_TC6_CTRL_HEADER_SIZE + OA_TC6_CTRL_REG_VALUE_SIZE * length +224	       OA_TC6_CTRL_IGNORED_SIZE;225}226 227static void oa_tc6_prepare_ctrl_spi_buf(struct oa_tc6 *tc6, u32 address,228					u32 value[], u8 length,229					enum oa_tc6_register_op reg_op)230{231	__be32 *tx_buf = tc6->spi_ctrl_tx_buf;232 233	*tx_buf = oa_tc6_prepare_ctrl_header(address, length, reg_op);234 235	if (reg_op == OA_TC6_CTRL_REG_WRITE)236		oa_tc6_update_ctrl_write_data(tc6, value, length);237}238 239static int oa_tc6_check_ctrl_write_reply(struct oa_tc6 *tc6, u8 size)240{241	u8 *tx_buf = tc6->spi_ctrl_tx_buf;242	u8 *rx_buf = tc6->spi_ctrl_rx_buf;243 244	rx_buf += OA_TC6_CTRL_IGNORED_SIZE;245 246	/* The echoed control write must match with the one that was247	 * transmitted.248	 */249	if (memcmp(tx_buf, rx_buf, size - OA_TC6_CTRL_IGNORED_SIZE))250		return -EPROTO;251 252	return 0;253}254 255static int oa_tc6_check_ctrl_read_reply(struct oa_tc6 *tc6, u8 size)256{257	u32 *rx_buf = tc6->spi_ctrl_rx_buf + OA_TC6_CTRL_IGNORED_SIZE;258	u32 *tx_buf = tc6->spi_ctrl_tx_buf;259 260	/* The echoed control read header must match with the one that was261	 * transmitted.262	 */263	if (*tx_buf != *rx_buf)264		return -EPROTO;265 266	return 0;267}268 269static void oa_tc6_copy_ctrl_read_data(struct oa_tc6 *tc6, u32 value[],270				       u8 length)271{272	__be32 *rx_buf = tc6->spi_ctrl_rx_buf + OA_TC6_CTRL_IGNORED_SIZE +273			 OA_TC6_CTRL_HEADER_SIZE;274 275	for (int i = 0; i < length; i++)276		value[i] = be32_to_cpu(*rx_buf++);277}278 279static int oa_tc6_perform_ctrl(struct oa_tc6 *tc6, u32 address, u32 value[],280			       u8 length, enum oa_tc6_register_op reg_op)281{282	u16 size;283	int ret;284 285	/* Prepare control command and copy to SPI control buffer */286	oa_tc6_prepare_ctrl_spi_buf(tc6, address, value, length, reg_op);287 288	size = oa_tc6_calculate_ctrl_buf_size(length);289 290	/* Perform SPI transfer */291	ret = oa_tc6_spi_transfer(tc6, OA_TC6_CTRL_HEADER, size);292	if (ret) {293		dev_err(&tc6->spi->dev, "SPI transfer failed for control: %d\n",294			ret);295		return ret;296	}297 298	/* Check echoed/received control write command reply for errors */299	if (reg_op == OA_TC6_CTRL_REG_WRITE)300		return oa_tc6_check_ctrl_write_reply(tc6, size);301 302	/* Check echoed/received control read command reply for errors */303	ret = oa_tc6_check_ctrl_read_reply(tc6, size);304	if (ret)305		return ret;306 307	oa_tc6_copy_ctrl_read_data(tc6, value, length);308 309	return 0;310}311 312/**313 * oa_tc6_read_registers - function for reading multiple consecutive registers.314 * @tc6: oa_tc6 struct.315 * @address: address of the first register to be read in the MAC-PHY.316 * @value: values to be read from the starting register address @address.317 * @length: number of consecutive registers to be read from @address.318 *319 * Maximum of 128 consecutive registers can be read starting at @address.320 *321 * Return: 0 on success otherwise failed.322 */323int oa_tc6_read_registers(struct oa_tc6 *tc6, u32 address, u32 value[],324			  u8 length)325{326	int ret;327 328	if (!length || length > OA_TC6_CTRL_MAX_REGISTERS) {329		dev_err(&tc6->spi->dev, "Invalid register length parameter\n");330		return -EINVAL;331	}332 333	mutex_lock(&tc6->spi_ctrl_lock);334	ret = oa_tc6_perform_ctrl(tc6, address, value, length,335				  OA_TC6_CTRL_REG_READ);336	mutex_unlock(&tc6->spi_ctrl_lock);337 338	return ret;339}340EXPORT_SYMBOL_GPL(oa_tc6_read_registers);341 342/**343 * oa_tc6_read_register - function for reading a MAC-PHY register.344 * @tc6: oa_tc6 struct.345 * @address: register address of the MAC-PHY to be read.346 * @value: value read from the @address register address of the MAC-PHY.347 *348 * Return: 0 on success otherwise failed.349 */350int oa_tc6_read_register(struct oa_tc6 *tc6, u32 address, u32 *value)351{352	return oa_tc6_read_registers(tc6, address, value, 1);353}354EXPORT_SYMBOL_GPL(oa_tc6_read_register);355 356/**357 * oa_tc6_write_registers - function for writing multiple consecutive registers.358 * @tc6: oa_tc6 struct.359 * @address: address of the first register to be written in the MAC-PHY.360 * @value: values to be written from the starting register address @address.361 * @length: number of consecutive registers to be written from @address.362 *363 * Maximum of 128 consecutive registers can be written starting at @address.364 *365 * Return: 0 on success otherwise failed.366 */367int oa_tc6_write_registers(struct oa_tc6 *tc6, u32 address, u32 value[],368			   u8 length)369{370	int ret;371 372	if (!length || length > OA_TC6_CTRL_MAX_REGISTERS) {373		dev_err(&tc6->spi->dev, "Invalid register length parameter\n");374		return -EINVAL;375	}376 377	mutex_lock(&tc6->spi_ctrl_lock);378	ret = oa_tc6_perform_ctrl(tc6, address, value, length,379				  OA_TC6_CTRL_REG_WRITE);380	mutex_unlock(&tc6->spi_ctrl_lock);381 382	return ret;383}384EXPORT_SYMBOL_GPL(oa_tc6_write_registers);385 386/**387 * oa_tc6_write_register - function for writing a MAC-PHY register.388 * @tc6: oa_tc6 struct.389 * @address: register address of the MAC-PHY to be written.390 * @value: value to be written in the @address register address of the MAC-PHY.391 *392 * Return: 0 on success otherwise failed.393 */394int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value)395{396	return oa_tc6_write_registers(tc6, address, &value, 1);397}398EXPORT_SYMBOL_GPL(oa_tc6_write_register);399 400static int oa_tc6_check_phy_reg_direct_access_capability(struct oa_tc6 *tc6)401{402	u32 regval;403	int ret;404 405	ret = oa_tc6_read_register(tc6, OA_TC6_REG_STDCAP, &regval);406	if (ret)407		return ret;408 409	if (!(regval & STDCAP_DIRECT_PHY_REG_ACCESS))410		return -ENODEV;411 412	return 0;413}414 415static void oa_tc6_handle_link_change(struct net_device *netdev)416{417	phy_print_status(netdev->phydev);418}419 420static int oa_tc6_mdiobus_read(struct mii_bus *bus, int addr, int regnum)421{422	struct oa_tc6 *tc6 = bus->priv;423	u32 regval;424	bool ret;425 426	ret = oa_tc6_read_register(tc6, OA_TC6_PHY_STD_REG_ADDR_BASE |427				   (regnum & OA_TC6_PHY_STD_REG_ADDR_MASK),428				   &regval);429	if (ret)430		return ret;431 432	return regval;433}434 435static int oa_tc6_mdiobus_write(struct mii_bus *bus, int addr, int regnum,436				u16 val)437{438	struct oa_tc6 *tc6 = bus->priv;439 440	return oa_tc6_write_register(tc6, OA_TC6_PHY_STD_REG_ADDR_BASE |441				     (regnum & OA_TC6_PHY_STD_REG_ADDR_MASK),442				     val);443}444 445static int oa_tc6_get_phy_c45_mms(int devnum)446{447	switch (devnum) {448	case MDIO_MMD_PCS:449		return OA_TC6_PHY_C45_PCS_MMS2;450	case MDIO_MMD_PMAPMD:451		return OA_TC6_PHY_C45_PMA_PMD_MMS3;452	case MDIO_MMD_VEND2:453		return OA_TC6_PHY_C45_VS_PLCA_MMS4;454	case MDIO_MMD_AN:455		return OA_TC6_PHY_C45_AUTO_NEG_MMS5;456	case MDIO_MMD_POWER_UNIT:457		return OA_TC6_PHY_C45_POWER_UNIT_MMS6;458	default:459		return -EOPNOTSUPP;460	}461}462 463static int oa_tc6_mdiobus_read_c45(struct mii_bus *bus, int addr, int devnum,464				   int regnum)465{466	struct oa_tc6 *tc6 = bus->priv;467	u32 regval;468	int ret;469 470	ret = oa_tc6_get_phy_c45_mms(devnum);471	if (ret < 0)472		return ret;473 474	ret = oa_tc6_read_register(tc6, (ret << 16) | regnum, &regval);475	if (ret)476		return ret;477 478	return regval;479}480 481static int oa_tc6_mdiobus_write_c45(struct mii_bus *bus, int addr, int devnum,482				    int regnum, u16 val)483{484	struct oa_tc6 *tc6 = bus->priv;485	int ret;486 487	ret = oa_tc6_get_phy_c45_mms(devnum);488	if (ret < 0)489		return ret;490 491	return oa_tc6_write_register(tc6, (ret << 16) | regnum, val);492}493 494static int oa_tc6_mdiobus_register(struct oa_tc6 *tc6)495{496	int ret;497 498	tc6->mdiobus = mdiobus_alloc();499	if (!tc6->mdiobus) {500		netdev_err(tc6->netdev, "MDIO bus alloc failed\n");501		return -ENOMEM;502	}503 504	tc6->mdiobus->priv = tc6;505	tc6->mdiobus->read = oa_tc6_mdiobus_read;506	tc6->mdiobus->write = oa_tc6_mdiobus_write;507	/* OPEN Alliance 10BASE-T1x compliance MAC-PHYs will have both C22 and508	 * C45 registers space. If the PHY is discovered via C22 bus protocol it509	 * assumes it uses C22 protocol and always uses C22 registers indirect510	 * access to access C45 registers. This is because, we don't have a511	 * clean separation between C22/C45 register space and C22/C45 MDIO bus512	 * protocols. Resulting, PHY C45 registers direct access can't be used513	 * which can save multiple SPI bus access. To support this feature, PHY514	 * drivers can set .read_mmd/.write_mmd in the PHY driver to call515	 * .read_c45/.write_c45. Ex: drivers/net/phy/microchip_t1s.c516	 */517	tc6->mdiobus->read_c45 = oa_tc6_mdiobus_read_c45;518	tc6->mdiobus->write_c45 = oa_tc6_mdiobus_write_c45;519	tc6->mdiobus->name = "oa-tc6-mdiobus";520	tc6->mdiobus->parent = tc6->dev;521 522	snprintf(tc6->mdiobus->id, ARRAY_SIZE(tc6->mdiobus->id), "%s",523		 dev_name(&tc6->spi->dev));524 525	ret = mdiobus_register(tc6->mdiobus);526	if (ret) {527		netdev_err(tc6->netdev, "Could not register MDIO bus\n");528		mdiobus_free(tc6->mdiobus);529		return ret;530	}531 532	return 0;533}534 535static void oa_tc6_mdiobus_unregister(struct oa_tc6 *tc6)536{537	mdiobus_unregister(tc6->mdiobus);538	mdiobus_free(tc6->mdiobus);539}540 541static int oa_tc6_phy_init(struct oa_tc6 *tc6)542{543	int ret;544 545	ret = oa_tc6_check_phy_reg_direct_access_capability(tc6);546	if (ret) {547		netdev_err(tc6->netdev,548			   "Direct PHY register access is not supported by the MAC-PHY\n");549		return ret;550	}551 552	ret = oa_tc6_mdiobus_register(tc6);553	if (ret)554		return ret;555 556	tc6->phydev = phy_find_first(tc6->mdiobus);557	if (!tc6->phydev) {558		netdev_err(tc6->netdev, "No PHY found\n");559		oa_tc6_mdiobus_unregister(tc6);560		return -ENODEV;561	}562 563	tc6->phydev->is_internal = true;564	ret = phy_connect_direct(tc6->netdev, tc6->phydev,565				 &oa_tc6_handle_link_change,566				 PHY_INTERFACE_MODE_INTERNAL);567	if (ret) {568		netdev_err(tc6->netdev, "Can't attach PHY to %s\n",569			   tc6->mdiobus->id);570		oa_tc6_mdiobus_unregister(tc6);571		return ret;572	}573 574	phy_attached_info(tc6->netdev->phydev);575 576	return 0;577}578 579static void oa_tc6_phy_exit(struct oa_tc6 *tc6)580{581	phy_disconnect(tc6->phydev);582	oa_tc6_mdiobus_unregister(tc6);583}584 585static int oa_tc6_read_status0(struct oa_tc6 *tc6)586{587	u32 regval;588	int ret;589 590	ret = oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, &regval);591	if (ret) {592		dev_err(&tc6->spi->dev, "STATUS0 register read failed: %d\n",593			ret);594		return 0;595	}596 597	return regval;598}599 600static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)601{602	u32 regval = RESET_SWRESET;603	int ret;604 605	ret = oa_tc6_write_register(tc6, OA_TC6_REG_RESET, regval);606	if (ret)607		return ret;608 609	/* Poll for soft reset complete for every 1ms until 1s timeout */610	ret = readx_poll_timeout(oa_tc6_read_status0, tc6, regval,611				 regval & STATUS0_RESETC,612				 STATUS0_RESETC_POLL_DELAY,613				 STATUS0_RESETC_POLL_TIMEOUT);614	if (ret)615		return -ENODEV;616 617	/* Clear the reset complete status */618	return oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, regval);619}620 621static int oa_tc6_unmask_macphy_error_interrupts(struct oa_tc6 *tc6)622{623	u32 regval;624	int ret;625 626	ret = oa_tc6_read_register(tc6, OA_TC6_REG_INT_MASK0, &regval);627	if (ret)628		return ret;629 630	regval &= ~(INT_MASK0_TX_PROTOCOL_ERR_MASK |631		    INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK |632		    INT_MASK0_LOSS_OF_FRAME_ERR_MASK |633		    INT_MASK0_HEADER_ERR_MASK);634 635	return oa_tc6_write_register(tc6, OA_TC6_REG_INT_MASK0, regval);636}637 638static int oa_tc6_enable_data_transfer(struct oa_tc6 *tc6)639{640	u32 value;641	int ret;642 643	ret = oa_tc6_read_register(tc6, OA_TC6_REG_CONFIG0, &value);644	if (ret)645		return ret;646 647	/* Enable configuration synchronization for data transfer */648	value |= CONFIG0_SYNC;649 650	return oa_tc6_write_register(tc6, OA_TC6_REG_CONFIG0, value);651}652 653static void oa_tc6_cleanup_ongoing_rx_skb(struct oa_tc6 *tc6)654{655	if (tc6->rx_skb) {656		tc6->netdev->stats.rx_dropped++;657		kfree_skb(tc6->rx_skb);658		tc6->rx_skb = NULL;659	}660}661 662static void oa_tc6_cleanup_ongoing_tx_skb(struct oa_tc6 *tc6)663{664	if (tc6->ongoing_tx_skb) {665		tc6->netdev->stats.tx_dropped++;666		kfree_skb(tc6->ongoing_tx_skb);667		tc6->ongoing_tx_skb = NULL;668	}669}670 671static int oa_tc6_process_extended_status(struct oa_tc6 *tc6)672{673	u32 value;674	int ret;675 676	ret = oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, &value);677	if (ret) {678		netdev_err(tc6->netdev, "STATUS0 register read failed: %d\n",679			   ret);680		return ret;681	}682 683	/* Clear the error interrupts status */684	ret = oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, value);685	if (ret) {686		netdev_err(tc6->netdev, "STATUS0 register write failed: %d\n",687			   ret);688		return ret;689	}690 691	if (FIELD_GET(STATUS0_RX_BUFFER_OVERFLOW_ERROR, value)) {692		tc6->rx_buf_overflow = true;693		oa_tc6_cleanup_ongoing_rx_skb(tc6);694		net_err_ratelimited("%s: Receive buffer overflow error\n",695				    tc6->netdev->name);696		return -EAGAIN;697	}698	if (FIELD_GET(STATUS0_TX_PROTOCOL_ERROR, value)) {699		netdev_err(tc6->netdev, "Transmit protocol error\n");700		return -ENODEV;701	}702	/* TODO: Currently loss of frame and header errors are treated as703	 * non-recoverable errors. They will be handled in the next version.704	 */705	if (FIELD_GET(STATUS0_LOSS_OF_FRAME_ERROR, value)) {706		netdev_err(tc6->netdev, "Loss of frame error\n");707		return -ENODEV;708	}709	if (FIELD_GET(STATUS0_HEADER_ERROR, value)) {710		netdev_err(tc6->netdev, "Header error\n");711		return -ENODEV;712	}713 714	return 0;715}716 717static int oa_tc6_process_rx_chunk_footer(struct oa_tc6 *tc6, u32 footer)718{719	/* Process rx chunk footer for the following,720	 * 1. tx credits721	 * 2. errors if any from MAC-PHY722	 * 3. receive chunks available723	 */724	tc6->tx_credits = FIELD_GET(OA_TC6_DATA_FOOTER_TX_CREDITS, footer);725	tc6->rx_chunks_available = FIELD_GET(OA_TC6_DATA_FOOTER_RX_CHUNKS,726					     footer);727 728	if (FIELD_GET(OA_TC6_DATA_FOOTER_EXTENDED_STS, footer)) {729		int ret = oa_tc6_process_extended_status(tc6);730 731		if (ret)732			return ret;733	}734 735	/* TODO: Currently received header bad and configuration unsync errors736	 * are treated as non-recoverable errors. They will be handled in the737	 * next version.738	 */739	if (FIELD_GET(OA_TC6_DATA_FOOTER_RXD_HEADER_BAD, footer)) {740		netdev_err(tc6->netdev, "Rxd header bad error\n");741		return -ENODEV;742	}743 744	if (!FIELD_GET(OA_TC6_DATA_FOOTER_CONFIG_SYNC, footer)) {745		netdev_err(tc6->netdev, "Config unsync error\n");746		return -ENODEV;747	}748 749	return 0;750}751 752static void oa_tc6_submit_rx_skb(struct oa_tc6 *tc6)753{754	tc6->rx_skb->protocol = eth_type_trans(tc6->rx_skb, tc6->netdev);755	tc6->netdev->stats.rx_packets++;756	tc6->netdev->stats.rx_bytes += tc6->rx_skb->len;757 758	netif_rx(tc6->rx_skb);759 760	tc6->rx_skb = NULL;761}762 763static void oa_tc6_update_rx_skb(struct oa_tc6 *tc6, u8 *payload, u8 length)764{765	memcpy(skb_put(tc6->rx_skb, length), payload, length);766}767 768static int oa_tc6_allocate_rx_skb(struct oa_tc6 *tc6)769{770	tc6->rx_skb = netdev_alloc_skb_ip_align(tc6->netdev, tc6->netdev->mtu +771						ETH_HLEN + ETH_FCS_LEN);772	if (!tc6->rx_skb) {773		tc6->netdev->stats.rx_dropped++;774		return -ENOMEM;775	}776 777	return 0;778}779 780static int oa_tc6_prcs_complete_rx_frame(struct oa_tc6 *tc6, u8 *payload,781					 u16 size)782{783	int ret;784 785	ret = oa_tc6_allocate_rx_skb(tc6);786	if (ret)787		return ret;788 789	oa_tc6_update_rx_skb(tc6, payload, size);790 791	oa_tc6_submit_rx_skb(tc6);792 793	return 0;794}795 796static int oa_tc6_prcs_rx_frame_start(struct oa_tc6 *tc6, u8 *payload, u16 size)797{798	int ret;799 800	ret = oa_tc6_allocate_rx_skb(tc6);801	if (ret)802		return ret;803 804	oa_tc6_update_rx_skb(tc6, payload, size);805 806	return 0;807}808 809static void oa_tc6_prcs_rx_frame_end(struct oa_tc6 *tc6, u8 *payload, u16 size)810{811	oa_tc6_update_rx_skb(tc6, payload, size);812 813	oa_tc6_submit_rx_skb(tc6);814}815 816static void oa_tc6_prcs_ongoing_rx_frame(struct oa_tc6 *tc6, u8 *payload,817					 u32 footer)818{819	oa_tc6_update_rx_skb(tc6, payload, OA_TC6_CHUNK_PAYLOAD_SIZE);820}821 822static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data,823					u32 footer)824{825	u8 start_byte_offset = FIELD_GET(OA_TC6_DATA_FOOTER_START_WORD_OFFSET,826					 footer) * sizeof(u32);827	u8 end_byte_offset = FIELD_GET(OA_TC6_DATA_FOOTER_END_BYTE_OFFSET,828				       footer);829	bool start_valid = FIELD_GET(OA_TC6_DATA_FOOTER_START_VALID, footer);830	bool end_valid = FIELD_GET(OA_TC6_DATA_FOOTER_END_VALID, footer);831	u16 size;832 833	/* Restart the new rx frame after receiving rx buffer overflow error */834	if (start_valid && tc6->rx_buf_overflow)835		tc6->rx_buf_overflow = false;836 837	if (tc6->rx_buf_overflow)838		return 0;839 840	/* Process the chunk with complete rx frame */841	if (start_valid && end_valid && start_byte_offset < end_byte_offset) {842		size = end_byte_offset + 1 - start_byte_offset;843		return oa_tc6_prcs_complete_rx_frame(tc6,844						     &data[start_byte_offset],845						     size);846	}847 848	/* Process the chunk with only rx frame start */849	if (start_valid && !end_valid) {850		size = OA_TC6_CHUNK_PAYLOAD_SIZE - start_byte_offset;851		return oa_tc6_prcs_rx_frame_start(tc6,852						  &data[start_byte_offset],853						  size);854	}855 856	/* Process the chunk with only rx frame end */857	if (end_valid && !start_valid) {858		size = end_byte_offset + 1;859		oa_tc6_prcs_rx_frame_end(tc6, data, size);860		return 0;861	}862 863	/* Process the chunk with previous rx frame end and next rx frame864	 * start.865	 */866	if (start_valid && end_valid && start_byte_offset > end_byte_offset) {867		/* After rx buffer overflow error received, there might be a868		 * possibility of getting an end valid of a previously869		 * incomplete rx frame along with the new rx frame start valid.870		 */871		if (tc6->rx_skb) {872			size = end_byte_offset + 1;873			oa_tc6_prcs_rx_frame_end(tc6, data, size);874		}875		size = OA_TC6_CHUNK_PAYLOAD_SIZE - start_byte_offset;876		return oa_tc6_prcs_rx_frame_start(tc6,877						  &data[start_byte_offset],878						  size);879	}880 881	/* Process the chunk with ongoing rx frame data */882	oa_tc6_prcs_ongoing_rx_frame(tc6, data, footer);883 884	return 0;885}886 887static u32 oa_tc6_get_rx_chunk_footer(struct oa_tc6 *tc6, u16 footer_offset)888{889	u8 *rx_buf = tc6->spi_data_rx_buf;890	__be32 footer;891 892	footer = *((__be32 *)&rx_buf[footer_offset]);893 894	return be32_to_cpu(footer);895}896 897static int oa_tc6_process_spi_data_rx_buf(struct oa_tc6 *tc6, u16 length)898{899	u16 no_of_rx_chunks = length / OA_TC6_CHUNK_SIZE;900	u32 footer;901	int ret;902 903	/* All the rx chunks in the receive SPI data buffer are examined here */904	for (int i = 0; i < no_of_rx_chunks; i++) {905		/* Last 4 bytes in each received chunk consist footer info */906		footer = oa_tc6_get_rx_chunk_footer(tc6, i * OA_TC6_CHUNK_SIZE +907						    OA_TC6_CHUNK_PAYLOAD_SIZE);908 909		ret = oa_tc6_process_rx_chunk_footer(tc6, footer);910		if (ret)911			return ret;912 913		/* If there is a data valid chunks then process it for the914		 * information needed to determine the validity and the location915		 * of the receive frame data.916		 */917		if (FIELD_GET(OA_TC6_DATA_FOOTER_DATA_VALID, footer)) {918			u8 *payload = tc6->spi_data_rx_buf + i *919				      OA_TC6_CHUNK_SIZE;920 921			ret = oa_tc6_prcs_rx_chunk_payload(tc6, payload,922							   footer);923			if (ret)924				return ret;925		}926	}927 928	return 0;929}930 931static __be32 oa_tc6_prepare_data_header(bool data_valid, bool start_valid,932					 bool end_valid, u8 end_byte_offset)933{934	u32 header = FIELD_PREP(OA_TC6_DATA_HEADER_DATA_NOT_CTRL,935				OA_TC6_DATA_HEADER) |936		     FIELD_PREP(OA_TC6_DATA_HEADER_DATA_VALID, data_valid) |937		     FIELD_PREP(OA_TC6_DATA_HEADER_START_VALID, start_valid) |938		     FIELD_PREP(OA_TC6_DATA_HEADER_END_VALID, end_valid) |939		     FIELD_PREP(OA_TC6_DATA_HEADER_END_BYTE_OFFSET,940				end_byte_offset);941 942	header |= FIELD_PREP(OA_TC6_DATA_HEADER_PARITY,943			     oa_tc6_get_parity(header));944 945	return cpu_to_be32(header);946}947 948static void oa_tc6_add_tx_skb_to_spi_buf(struct oa_tc6 *tc6)949{950	enum oa_tc6_data_end_valid_info end_valid = OA_TC6_DATA_END_INVALID;951	__be32 *tx_buf = tc6->spi_data_tx_buf + tc6->spi_data_tx_buf_offset;952	u16 remaining_len = tc6->ongoing_tx_skb->len - tc6->tx_skb_offset;953	u8 *tx_skb_data = tc6->ongoing_tx_skb->data + tc6->tx_skb_offset;954	enum oa_tc6_data_start_valid_info start_valid;955	u8 end_byte_offset = 0;956	u16 length_to_copy;957 958	/* Initial value is assigned here to avoid more than 80 characters in959	 * the declaration place.960	 */961	start_valid = OA_TC6_DATA_START_INVALID;962 963	/* Set start valid if the current tx chunk contains the start of the tx964	 * ethernet frame.965	 */966	if (!tc6->tx_skb_offset)967		start_valid = OA_TC6_DATA_START_VALID;968 969	/* If the remaining tx skb length is more than the chunk payload size of970	 * 64 bytes then copy only 64 bytes and leave the ongoing tx skb for971	 * next tx chunk.972	 */973	length_to_copy = min_t(u16, remaining_len, OA_TC6_CHUNK_PAYLOAD_SIZE);974 975	/* Copy the tx skb data to the tx chunk payload buffer */976	memcpy(tx_buf + 1, tx_skb_data, length_to_copy);977	tc6->tx_skb_offset += length_to_copy;978 979	/* Set end valid if the current tx chunk contains the end of the tx980	 * ethernet frame.981	 */982	if (tc6->ongoing_tx_skb->len == tc6->tx_skb_offset) {983		end_valid = OA_TC6_DATA_END_VALID;984		end_byte_offset = length_to_copy - 1;985		tc6->tx_skb_offset = 0;986		tc6->netdev->stats.tx_bytes += tc6->ongoing_tx_skb->len;987		tc6->netdev->stats.tx_packets++;988		kfree_skb(tc6->ongoing_tx_skb);989		tc6->ongoing_tx_skb = NULL;990	}991 992	*tx_buf = oa_tc6_prepare_data_header(OA_TC6_DATA_VALID, start_valid,993					     end_valid, end_byte_offset);994	tc6->spi_data_tx_buf_offset += OA_TC6_CHUNK_SIZE;995}996 997static u16 oa_tc6_prepare_spi_tx_buf_for_tx_skbs(struct oa_tc6 *tc6)998{999	u16 used_tx_credits;1000 1001	/* Get tx skbs and convert them into tx chunks based on the tx credits1002	 * available.1003	 */1004	for (used_tx_credits = 0; used_tx_credits < tc6->tx_credits;1005	     used_tx_credits++) {1006		if (!tc6->ongoing_tx_skb) {1007			tc6->ongoing_tx_skb = tc6->waiting_tx_skb;1008			tc6->waiting_tx_skb = NULL;1009		}1010		if (!tc6->ongoing_tx_skb)1011			break;1012		oa_tc6_add_tx_skb_to_spi_buf(tc6);1013	}1014 1015	return used_tx_credits * OA_TC6_CHUNK_SIZE;1016}1017 1018static void oa_tc6_add_empty_chunks_to_spi_buf(struct oa_tc6 *tc6,1019					       u16 needed_empty_chunks)1020{1021	__be32 header;1022 1023	header = oa_tc6_prepare_data_header(OA_TC6_DATA_INVALID,1024					    OA_TC6_DATA_START_INVALID,1025					    OA_TC6_DATA_END_INVALID, 0);1026 1027	while (needed_empty_chunks--) {1028		__be32 *tx_buf = tc6->spi_data_tx_buf +1029				 tc6->spi_data_tx_buf_offset;1030 1031		*tx_buf = header;1032		tc6->spi_data_tx_buf_offset += OA_TC6_CHUNK_SIZE;1033	}1034}1035 1036static u16 oa_tc6_prepare_spi_tx_buf_for_rx_chunks(struct oa_tc6 *tc6, u16 len)1037{1038	u16 tx_chunks = len / OA_TC6_CHUNK_SIZE;1039	u16 needed_empty_chunks;1040 1041	/* If there are more chunks to receive than to transmit, we need to add1042	 * enough empty tx chunks to allow the reception of the excess rx1043	 * chunks.1044	 */1045	if (tx_chunks >= tc6->rx_chunks_available)1046		return len;1047 1048	needed_empty_chunks = tc6->rx_chunks_available - tx_chunks;1049 1050	oa_tc6_add_empty_chunks_to_spi_buf(tc6, needed_empty_chunks);1051 1052	return needed_empty_chunks * OA_TC6_CHUNK_SIZE + len;1053}1054 1055static int oa_tc6_try_spi_transfer(struct oa_tc6 *tc6)1056{1057	int ret;1058 1059	while (true) {1060		u16 spi_len = 0;1061 1062		tc6->spi_data_tx_buf_offset = 0;1063 1064		if (tc6->ongoing_tx_skb || tc6->waiting_tx_skb)1065			spi_len = oa_tc6_prepare_spi_tx_buf_for_tx_skbs(tc6);1066 1067		spi_len = oa_tc6_prepare_spi_tx_buf_for_rx_chunks(tc6, spi_len);1068 1069		if (tc6->int_flag) {1070			tc6->int_flag = false;1071			if (spi_len == 0) {1072				oa_tc6_add_empty_chunks_to_spi_buf(tc6, 1);1073				spi_len = OA_TC6_CHUNK_SIZE;1074			}1075		}1076 1077		if (spi_len == 0)1078			break;1079 1080		ret = oa_tc6_spi_transfer(tc6, OA_TC6_DATA_HEADER, spi_len);1081		if (ret) {1082			netdev_err(tc6->netdev, "SPI data transfer failed: %d\n",1083				   ret);1084			return ret;1085		}1086 1087		ret = oa_tc6_process_spi_data_rx_buf(tc6, spi_len);1088		if (ret) {1089			if (ret == -EAGAIN)1090				continue;1091 1092			oa_tc6_cleanup_ongoing_tx_skb(tc6);1093			oa_tc6_cleanup_ongoing_rx_skb(tc6);1094			netdev_err(tc6->netdev, "Device error: %d\n", ret);1095			return ret;1096		}1097 1098		if (!tc6->waiting_tx_skb && netif_queue_stopped(tc6->netdev))1099			netif_wake_queue(tc6->netdev);1100	}1101 1102	return 0;1103}1104 1105static int oa_tc6_spi_thread_handler(void *data)1106{1107	struct oa_tc6 *tc6 = data;1108	int ret;1109 1110	while (likely(!kthread_should_stop())) {1111		/* This kthread will be waken up if there is a tx skb or mac-phy1112		 * interrupt to perform spi transfer with tx chunks.1113		 */1114		wait_event_interruptible(tc6->spi_wq, tc6->waiting_tx_skb ||1115					 tc6->int_flag ||1116					 kthread_should_stop());1117 1118		if (kthread_should_stop())1119			break;1120 1121		ret = oa_tc6_try_spi_transfer(tc6);1122		if (ret)1123			return ret;1124	}1125 1126	return 0;1127}1128 1129static int oa_tc6_update_buffer_status_from_register(struct oa_tc6 *tc6)1130{1131	u32 value;1132	int ret;1133 1134	/* Initially tx credits and rx chunks available to be updated from the1135	 * register as there is no data transfer performed yet. Later they will1136	 * be updated from the rx footer.1137	 */1138	ret = oa_tc6_read_register(tc6, OA_TC6_REG_BUFFER_STATUS, &value);1139	if (ret)1140		return ret;1141 1142	tc6->tx_credits = FIELD_GET(BUFFER_STATUS_TX_CREDITS_AVAILABLE, value);1143	tc6->rx_chunks_available = FIELD_GET(BUFFER_STATUS_RX_CHUNKS_AVAILABLE,1144					     value);1145 1146	return 0;1147}1148 1149static irqreturn_t oa_tc6_macphy_isr(int irq, void *data)1150{1151	struct oa_tc6 *tc6 = data;1152 1153	/* MAC-PHY interrupt can occur for the following reasons.1154	 * - availability of tx credits if it was 0 before and not reported in1155	 *   the previous rx footer.1156	 * - availability of rx chunks if it was 0 before and not reported in1157	 *   the previous rx footer.1158	 * - extended status event not reported in the previous rx footer.1159	 */1160	tc6->int_flag = true;1161	/* Wake spi kthread to perform spi transfer */1162	wake_up_interruptible(&tc6->spi_wq);1163 1164	return IRQ_HANDLED;1165}1166 1167/**1168 * oa_tc6_zero_align_receive_frame_enable - function to enable zero align1169 * receive frame feature.1170 * @tc6: oa_tc6 struct.1171 *1172 * Return: 0 on success otherwise failed.1173 */1174int oa_tc6_zero_align_receive_frame_enable(struct oa_tc6 *tc6)1175{1176	u32 regval;1177	int ret;1178 1179	ret = oa_tc6_read_register(tc6, OA_TC6_REG_CONFIG0, &regval);1180	if (ret)1181		return ret;1182 1183	/* Set Zero-Align Receive Frame Enable */1184	regval |= CONFIG0_ZARFE_ENABLE;1185 1186	return oa_tc6_write_register(tc6, OA_TC6_REG_CONFIG0, regval);1187}1188EXPORT_SYMBOL_GPL(oa_tc6_zero_align_receive_frame_enable);1189 1190/**1191 * oa_tc6_start_xmit - function for sending the tx skb which consists ethernet1192 * frame.1193 * @tc6: oa_tc6 struct.1194 * @skb: socket buffer in which the ethernet frame is stored.1195 *1196 * Return: NETDEV_TX_OK if the transmit ethernet frame skb added in the tx_skb_q1197 * otherwise returns NETDEV_TX_BUSY.1198 */1199netdev_tx_t oa_tc6_start_xmit(struct oa_tc6 *tc6, struct sk_buff *skb)1200{1201	if (tc6->waiting_tx_skb) {1202		netif_stop_queue(tc6->netdev);1203		return NETDEV_TX_BUSY;1204	}1205 1206	if (skb_linearize(skb)) {1207		dev_kfree_skb_any(skb);1208		tc6->netdev->stats.tx_dropped++;1209		return NETDEV_TX_OK;1210	}1211 1212	tc6->waiting_tx_skb = skb;1213 1214	/* Wake spi kthread to perform spi transfer */1215	wake_up_interruptible(&tc6->spi_wq);1216 1217	return NETDEV_TX_OK;1218}1219EXPORT_SYMBOL_GPL(oa_tc6_start_xmit);1220 1221/**1222 * oa_tc6_init - allocates and initializes oa_tc6 structure.1223 * @spi: device with which data will be exchanged.1224 * @netdev: network device interface structure.1225 *1226 * Return: pointer reference to the oa_tc6 structure if the MAC-PHY1227 * initialization is successful otherwise NULL.1228 */1229struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev)1230{1231	struct oa_tc6 *tc6;1232	int ret;1233 1234	tc6 = devm_kzalloc(&spi->dev, sizeof(*tc6), GFP_KERNEL);1235	if (!tc6)1236		return NULL;1237 1238	tc6->spi = spi;1239	tc6->netdev = netdev;1240	SET_NETDEV_DEV(netdev, &spi->dev);1241	mutex_init(&tc6->spi_ctrl_lock);1242 1243	/* Set the SPI controller to pump at realtime priority */1244	tc6->spi->rt = true;1245	spi_setup(tc6->spi);1246 1247	tc6->spi_ctrl_tx_buf = devm_kzalloc(&tc6->spi->dev,1248					    OA_TC6_CTRL_SPI_BUF_SIZE,1249					    GFP_KERNEL);1250	if (!tc6->spi_ctrl_tx_buf)1251		return NULL;1252 1253	tc6->spi_ctrl_rx_buf = devm_kzalloc(&tc6->spi->dev,1254					    OA_TC6_CTRL_SPI_BUF_SIZE,1255					    GFP_KERNEL);1256	if (!tc6->spi_ctrl_rx_buf)1257		return NULL;1258 1259	tc6->spi_data_tx_buf = devm_kzalloc(&tc6->spi->dev,1260					    OA_TC6_SPI_DATA_BUF_SIZE,1261					    GFP_KERNEL);1262	if (!tc6->spi_data_tx_buf)1263		return NULL;1264 1265	tc6->spi_data_rx_buf = devm_kzalloc(&tc6->spi->dev,1266					    OA_TC6_SPI_DATA_BUF_SIZE,1267					    GFP_KERNEL);1268	if (!tc6->spi_data_rx_buf)1269		return NULL;1270 1271	ret = oa_tc6_sw_reset_macphy(tc6);1272	if (ret) {1273		dev_err(&tc6->spi->dev,1274			"MAC-PHY software reset failed: %d\n", ret);1275		return NULL;1276	}1277 1278	ret = oa_tc6_unmask_macphy_error_interrupts(tc6);1279	if (ret) {1280		dev_err(&tc6->spi->dev,1281			"MAC-PHY error interrupts unmask failed: %d\n", ret);1282		return NULL;1283	}1284 1285	ret = oa_tc6_phy_init(tc6);1286	if (ret) {1287		dev_err(&tc6->spi->dev,1288			"MAC internal PHY initialization failed: %d\n", ret);1289		return NULL;1290	}1291 1292	ret = oa_tc6_enable_data_transfer(tc6);1293	if (ret) {1294		dev_err(&tc6->spi->dev, "Failed to enable data transfer: %d\n",1295			ret);1296		goto phy_exit;1297	}1298 1299	ret = oa_tc6_update_buffer_status_from_register(tc6);1300	if (ret) {1301		dev_err(&tc6->spi->dev,1302			"Failed to update buffer status: %d\n", ret);1303		goto phy_exit;1304	}1305 1306	init_waitqueue_head(&tc6->spi_wq);1307 1308	tc6->spi_thread = kthread_run(oa_tc6_spi_thread_handler, tc6,1309				      "oa-tc6-spi-thread");1310	if (IS_ERR(tc6->spi_thread)) {1311		dev_err(&tc6->spi->dev, "Failed to create SPI thread\n");1312		goto phy_exit;1313	}1314 1315	sched_set_fifo(tc6->spi_thread);1316 1317	ret = devm_request_irq(&tc6->spi->dev, tc6->spi->irq, oa_tc6_macphy_isr,1318			       IRQF_TRIGGER_FALLING, dev_name(&tc6->spi->dev),1319			       tc6);1320	if (ret) {1321		dev_err(&tc6->spi->dev, "Failed to request macphy isr %d\n",1322			ret);1323		goto kthread_stop;1324	}1325 1326	/* oa_tc6_sw_reset_macphy() function resets and clears the MAC-PHY reset1327	 * complete status. IRQ is also asserted on reset completion and it is1328	 * remain asserted until MAC-PHY receives a data chunk. So performing an1329	 * empty data chunk transmission will deassert the IRQ. Refer section1330	 * 7.7 and 9.2.8.8 in the OPEN Alliance specification for more details.1331	 */1332	tc6->int_flag = true;1333	wake_up_interruptible(&tc6->spi_wq);1334 1335	return tc6;1336 1337kthread_stop:1338	kthread_stop(tc6->spi_thread);1339phy_exit:1340	oa_tc6_phy_exit(tc6);1341	return NULL;1342}1343EXPORT_SYMBOL_GPL(oa_tc6_init);1344 1345/**1346 * oa_tc6_exit - exit function.1347 * @tc6: oa_tc6 struct.1348 */1349void oa_tc6_exit(struct oa_tc6 *tc6)1350{1351	oa_tc6_phy_exit(tc6);1352	kthread_stop(tc6->spi_thread);1353	dev_kfree_skb_any(tc6->ongoing_tx_skb);1354	dev_kfree_skb_any(tc6->waiting_tx_skb);1355	dev_kfree_skb_any(tc6->rx_skb);1356}1357EXPORT_SYMBOL_GPL(oa_tc6_exit);1358 1359MODULE_DESCRIPTION("OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface Lib");1360MODULE_AUTHOR("Parthiban Veerasooran <parthiban.veerasooran@microchip.com>");1361MODULE_LICENSE("GPL");1362