// SPDX-License-Identifier: GPL-2.0+ /* * OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface framework * * Author: Parthiban Veerasooran */ #include #include #include #include #include /* 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 */ /* Configuration Register #0 */ #define OA_TC6_REG_CONFIG0 0x0004 #define CONFIG0_SYNC BIT(15) #define CONFIG0_ZARFE_ENABLE BIT(12) /* Status Register #0 */ #define OA_TC6_REG_STATUS0 0x0008 #define STATUS0_RESETC BIT(6) /* Reset Complete */ #define STATUS0_HEADER_ERROR BIT(5) #define STATUS0_LOSS_OF_FRAME_ERROR BIT(4) #define STATUS0_RX_BUFFER_OVERFLOW_ERROR BIT(3) #define STATUS0_TX_PROTOCOL_ERROR BIT(0) /* Buffer Status Register */ #define OA_TC6_REG_BUFFER_STATUS 0x000B #define BUFFER_STATUS_TX_CREDITS_AVAILABLE GENMASK(15, 8) #define BUFFER_STATUS_RX_CHUNKS_AVAILABLE GENMASK(7, 0) /* 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) /* 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) #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) /* Data header */ #define OA_TC6_DATA_HEADER_DATA_NOT_CTRL BIT(31) #define OA_TC6_DATA_HEADER_DATA_VALID BIT(21) #define OA_TC6_DATA_HEADER_START_VALID BIT(20) #define OA_TC6_DATA_HEADER_START_WORD_OFFSET GENMASK(19, 16) #define OA_TC6_DATA_HEADER_END_VALID BIT(14) #define OA_TC6_DATA_HEADER_END_BYTE_OFFSET GENMASK(13, 8) #define OA_TC6_DATA_HEADER_PARITY BIT(0) /* Data footer */ #define OA_TC6_DATA_FOOTER_EXTENDED_STS BIT(31) #define OA_TC6_DATA_FOOTER_RXD_HEADER_BAD BIT(30) #define OA_TC6_DATA_FOOTER_CONFIG_SYNC BIT(29) #define OA_TC6_DATA_FOOTER_RX_CHUNKS GENMASK(28, 24) #define OA_TC6_DATA_FOOTER_DATA_VALID BIT(21) #define OA_TC6_DATA_FOOTER_START_VALID BIT(20) #define OA_TC6_DATA_FOOTER_START_WORD_OFFSET GENMASK(19, 16) #define OA_TC6_DATA_FOOTER_END_VALID BIT(14) #define OA_TC6_DATA_FOOTER_END_BYTE_OFFSET GENMASK(13, 8) #define OA_TC6_DATA_FOOTER_TX_CREDITS GENMASK(5, 1) /* 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 #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) #define OA_TC6_CHUNK_PAYLOAD_SIZE 64 #define OA_TC6_DATA_HEADER_SIZE 4 #define OA_TC6_CHUNK_SIZE (OA_TC6_DATA_HEADER_SIZE +\ OA_TC6_CHUNK_PAYLOAD_SIZE) #define OA_TC6_MAX_TX_CHUNKS 48 #define OA_TC6_SPI_DATA_BUF_SIZE (OA_TC6_MAX_TX_CHUNKS *\ OA_TC6_CHUNK_SIZE) #define STATUS0_RESETC_POLL_DELAY 1000 #define STATUS0_RESETC_POLL_TIMEOUT 1000000 /* 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; void *spi_ctrl_rx_buf; void *spi_data_tx_buf; void *spi_data_rx_buf; struct sk_buff *ongoing_tx_skb; struct sk_buff *waiting_tx_skb; struct sk_buff *rx_skb; struct task_struct *spi_thread; wait_queue_head_t spi_wq; u16 tx_skb_offset; u16 spi_data_tx_buf_offset; u16 tx_credits; u8 rx_chunks_available; bool rx_buf_overflow; bool int_flag; }; enum oa_tc6_header_type { OA_TC6_CTRL_HEADER, OA_TC6_DATA_HEADER, }; enum oa_tc6_register_op { OA_TC6_CTRL_REG_READ = 0, OA_TC6_CTRL_REG_WRITE = 1, }; enum oa_tc6_data_valid_info { OA_TC6_DATA_INVALID, OA_TC6_DATA_VALID, }; enum oa_tc6_data_start_valid_info { OA_TC6_DATA_START_INVALID, OA_TC6_DATA_START_VALID, }; enum oa_tc6_data_end_valid_info { OA_TC6_DATA_END_INVALID, OA_TC6_DATA_END_VALID, }; 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; if (header_type == OA_TC6_DATA_HEADER) { xfer.tx_buf = tc6->spi_data_tx_buf; xfer.rx_buf = tc6->spi_data_rx_buf; } else { 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); 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) { 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_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) { 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 */ 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. * @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); 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, ®val); 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), ®val); 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, ®val); 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; int ret; ret = oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, ®val); 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); } 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, ®val); 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); } static int oa_tc6_enable_data_transfer(struct oa_tc6 *tc6) { u32 value; int ret; ret = oa_tc6_read_register(tc6, OA_TC6_REG_CONFIG0, &value); if (ret) return ret; /* Enable configuration synchronization for data transfer */ value |= CONFIG0_SYNC; return oa_tc6_write_register(tc6, OA_TC6_REG_CONFIG0, value); } static void oa_tc6_cleanup_ongoing_rx_skb(struct oa_tc6 *tc6) { if (tc6->rx_skb) { tc6->netdev->stats.rx_dropped++; kfree_skb(tc6->rx_skb); tc6->rx_skb = NULL; } } static void oa_tc6_cleanup_ongoing_tx_skb(struct oa_tc6 *tc6) { if (tc6->ongoing_tx_skb) { tc6->netdev->stats.tx_dropped++; kfree_skb(tc6->ongoing_tx_skb); tc6->ongoing_tx_skb = NULL; } } static int oa_tc6_process_extended_status(struct oa_tc6 *tc6) { u32 value; int ret; ret = oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, &value); if (ret) { netdev_err(tc6->netdev, "STATUS0 register read failed: %d\n", ret); return ret; } /* Clear the error interrupts status */ ret = oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, value); if (ret) { netdev_err(tc6->netdev, "STATUS0 register write failed: %d\n", ret); return ret; } if (FIELD_GET(STATUS0_RX_BUFFER_OVERFLOW_ERROR, value)) { tc6->rx_buf_overflow = true; oa_tc6_cleanup_ongoing_rx_skb(tc6); net_err_ratelimited("%s: Receive buffer overflow error\n", tc6->netdev->name); return -EAGAIN; } if (FIELD_GET(STATUS0_TX_PROTOCOL_ERROR, value)) { netdev_err(tc6->netdev, "Transmit protocol error\n"); return -ENODEV; } /* TODO: Currently loss of frame and header errors are treated as * non-recoverable errors. They will be handled in the next version. */ if (FIELD_GET(STATUS0_LOSS_OF_FRAME_ERROR, value)) { netdev_err(tc6->netdev, "Loss of frame error\n"); return -ENODEV; } if (FIELD_GET(STATUS0_HEADER_ERROR, value)) { netdev_err(tc6->netdev, "Header error\n"); return -ENODEV; } return 0; } static int oa_tc6_process_rx_chunk_footer(struct oa_tc6 *tc6, u32 footer) { /* Process rx chunk footer for the following, * 1. tx credits * 2. errors if any from MAC-PHY * 3. receive chunks available */ tc6->tx_credits = FIELD_GET(OA_TC6_DATA_FOOTER_TX_CREDITS, footer); tc6->rx_chunks_available = FIELD_GET(OA_TC6_DATA_FOOTER_RX_CHUNKS, footer); if (FIELD_GET(OA_TC6_DATA_FOOTER_EXTENDED_STS, footer)) { int ret = oa_tc6_process_extended_status(tc6); if (ret) return ret; } /* TODO: Currently received header bad and configuration unsync errors * are treated as non-recoverable errors. They will be handled in the * next version. */ if (FIELD_GET(OA_TC6_DATA_FOOTER_RXD_HEADER_BAD, footer)) { netdev_err(tc6->netdev, "Rxd header bad error\n"); return -ENODEV; } if (!FIELD_GET(OA_TC6_DATA_FOOTER_CONFIG_SYNC, footer)) { netdev_err(tc6->netdev, "Config unsync error\n"); return -ENODEV; } return 0; } static void oa_tc6_submit_rx_skb(struct oa_tc6 *tc6) { tc6->rx_skb->protocol = eth_type_trans(tc6->rx_skb, tc6->netdev); tc6->netdev->stats.rx_packets++; tc6->netdev->stats.rx_bytes += tc6->rx_skb->len; netif_rx(tc6->rx_skb); tc6->rx_skb = NULL; } static void oa_tc6_update_rx_skb(struct oa_tc6 *tc6, u8 *payload, u8 length) { memcpy(skb_put(tc6->rx_skb, length), payload, length); } static int oa_tc6_allocate_rx_skb(struct oa_tc6 *tc6) { tc6->rx_skb = netdev_alloc_skb_ip_align(tc6->netdev, tc6->netdev->mtu + ETH_HLEN + ETH_FCS_LEN); if (!tc6->rx_skb) { tc6->netdev->stats.rx_dropped++; return -ENOMEM; } return 0; } static int oa_tc6_prcs_complete_rx_frame(struct oa_tc6 *tc6, u8 *payload, u16 size) { int ret; ret = oa_tc6_allocate_rx_skb(tc6); if (ret) return ret; oa_tc6_update_rx_skb(tc6, payload, size); oa_tc6_submit_rx_skb(tc6); return 0; } static int oa_tc6_prcs_rx_frame_start(struct oa_tc6 *tc6, u8 *payload, u16 size) { int ret; ret = oa_tc6_allocate_rx_skb(tc6); if (ret) return ret; oa_tc6_update_rx_skb(tc6, payload, size); return 0; } static void oa_tc6_prcs_rx_frame_end(struct oa_tc6 *tc6, u8 *payload, u16 size) { oa_tc6_update_rx_skb(tc6, payload, size); oa_tc6_submit_rx_skb(tc6); } static void oa_tc6_prcs_ongoing_rx_frame(struct oa_tc6 *tc6, u8 *payload, u32 footer) { oa_tc6_update_rx_skb(tc6, payload, OA_TC6_CHUNK_PAYLOAD_SIZE); } static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data, u32 footer) { u8 start_byte_offset = FIELD_GET(OA_TC6_DATA_FOOTER_START_WORD_OFFSET, footer) * sizeof(u32); u8 end_byte_offset = FIELD_GET(OA_TC6_DATA_FOOTER_END_BYTE_OFFSET, footer); bool start_valid = FIELD_GET(OA_TC6_DATA_FOOTER_START_VALID, footer); bool end_valid = FIELD_GET(OA_TC6_DATA_FOOTER_END_VALID, footer); u16 size; /* Restart the new rx frame after receiving rx buffer overflow error */ if (start_valid && tc6->rx_buf_overflow) tc6->rx_buf_overflow = false; if (tc6->rx_buf_overflow) return 0; /* Process the chunk with complete rx frame */ if (start_valid && end_valid && start_byte_offset < end_byte_offset) { size = end_byte_offset + 1 - start_byte_offset; return oa_tc6_prcs_complete_rx_frame(tc6, &data[start_byte_offset], size); } /* Process the chunk with only rx frame start */ if (start_valid && !end_valid) { size = OA_TC6_CHUNK_PAYLOAD_SIZE - start_byte_offset; return oa_tc6_prcs_rx_frame_start(tc6, &data[start_byte_offset], size); } /* Process the chunk with only rx frame end */ if (end_valid && !start_valid) { size = end_byte_offset + 1; oa_tc6_prcs_rx_frame_end(tc6, data, size); return 0; } /* Process the chunk with previous rx frame end and next rx frame * start. */ if (start_valid && end_valid && start_byte_offset > end_byte_offset) { /* After rx buffer overflow error received, there might be a * possibility of getting an end valid of a previously * incomplete rx frame along with the new rx frame start valid. */ if (tc6->rx_skb) { size = end_byte_offset + 1; oa_tc6_prcs_rx_frame_end(tc6, data, size); } size = OA_TC6_CHUNK_PAYLOAD_SIZE - start_byte_offset; return oa_tc6_prcs_rx_frame_start(tc6, &data[start_byte_offset], size); } /* Process the chunk with ongoing rx frame data */ oa_tc6_prcs_ongoing_rx_frame(tc6, data, footer); return 0; } static u32 oa_tc6_get_rx_chunk_footer(struct oa_tc6 *tc6, u16 footer_offset) { u8 *rx_buf = tc6->spi_data_rx_buf; __be32 footer; footer = *((__be32 *)&rx_buf[footer_offset]); return be32_to_cpu(footer); } static int oa_tc6_process_spi_data_rx_buf(struct oa_tc6 *tc6, u16 length) { u16 no_of_rx_chunks = length / OA_TC6_CHUNK_SIZE; u32 footer; int ret; /* All the rx chunks in the receive SPI data buffer are examined here */ for (int i = 0; i < no_of_rx_chunks; i++) { /* Last 4 bytes in each received chunk consist footer info */ footer = oa_tc6_get_rx_chunk_footer(tc6, i * OA_TC6_CHUNK_SIZE + OA_TC6_CHUNK_PAYLOAD_SIZE); ret = oa_tc6_process_rx_chunk_footer(tc6, footer); if (ret) return ret; /* If there is a data valid chunks then process it for the * information needed to determine the validity and the location * of the receive frame data. */ if (FIELD_GET(OA_TC6_DATA_FOOTER_DATA_VALID, footer)) { u8 *payload = tc6->spi_data_rx_buf + i * OA_TC6_CHUNK_SIZE; ret = oa_tc6_prcs_rx_chunk_payload(tc6, payload, footer); if (ret) return ret; } } return 0; } static __be32 oa_tc6_prepare_data_header(bool data_valid, bool start_valid, bool end_valid, u8 end_byte_offset) { u32 header = FIELD_PREP(OA_TC6_DATA_HEADER_DATA_NOT_CTRL, OA_TC6_DATA_HEADER) | FIELD_PREP(OA_TC6_DATA_HEADER_DATA_VALID, data_valid) | FIELD_PREP(OA_TC6_DATA_HEADER_START_VALID, start_valid) | FIELD_PREP(OA_TC6_DATA_HEADER_END_VALID, end_valid) | FIELD_PREP(OA_TC6_DATA_HEADER_END_BYTE_OFFSET, end_byte_offset); header |= FIELD_PREP(OA_TC6_DATA_HEADER_PARITY, oa_tc6_get_parity(header)); return cpu_to_be32(header); } static void oa_tc6_add_tx_skb_to_spi_buf(struct oa_tc6 *tc6) { enum oa_tc6_data_end_valid_info end_valid = OA_TC6_DATA_END_INVALID; __be32 *tx_buf = tc6->spi_data_tx_buf + tc6->spi_data_tx_buf_offset; u16 remaining_len = tc6->ongoing_tx_skb->len - tc6->tx_skb_offset; u8 *tx_skb_data = tc6->ongoing_tx_skb->data + tc6->tx_skb_offset; enum oa_tc6_data_start_valid_info start_valid; u8 end_byte_offset = 0; u16 length_to_copy; /* Initial value is assigned here to avoid more than 80 characters in * the declaration place. */ start_valid = OA_TC6_DATA_START_INVALID; /* Set start valid if the current tx chunk contains the start of the tx * ethernet frame. */ if (!tc6->tx_skb_offset) start_valid = OA_TC6_DATA_START_VALID; /* If the remaining tx skb length is more than the chunk payload size of * 64 bytes then copy only 64 bytes and leave the ongoing tx skb for * next tx chunk. */ length_to_copy = min_t(u16, remaining_len, OA_TC6_CHUNK_PAYLOAD_SIZE); /* Copy the tx skb data to the tx chunk payload buffer */ memcpy(tx_buf + 1, tx_skb_data, length_to_copy); tc6->tx_skb_offset += length_to_copy; /* Set end valid if the current tx chunk contains the end of the tx * ethernet frame. */ if (tc6->ongoing_tx_skb->len == tc6->tx_skb_offset) { end_valid = OA_TC6_DATA_END_VALID; end_byte_offset = length_to_copy - 1; tc6->tx_skb_offset = 0; tc6->netdev->stats.tx_bytes += tc6->ongoing_tx_skb->len; tc6->netdev->stats.tx_packets++; kfree_skb(tc6->ongoing_tx_skb); tc6->ongoing_tx_skb = NULL; } *tx_buf = oa_tc6_prepare_data_header(OA_TC6_DATA_VALID, start_valid, end_valid, end_byte_offset); tc6->spi_data_tx_buf_offset += OA_TC6_CHUNK_SIZE; } static u16 oa_tc6_prepare_spi_tx_buf_for_tx_skbs(struct oa_tc6 *tc6) { u16 used_tx_credits; /* Get tx skbs and convert them into tx chunks based on the tx credits * available. */ for (used_tx_credits = 0; used_tx_credits < tc6->tx_credits; used_tx_credits++) { if (!tc6->ongoing_tx_skb) { tc6->ongoing_tx_skb = tc6->waiting_tx_skb; tc6->waiting_tx_skb = NULL; } if (!tc6->ongoing_tx_skb) break; oa_tc6_add_tx_skb_to_spi_buf(tc6); } return used_tx_credits * OA_TC6_CHUNK_SIZE; } static void oa_tc6_add_empty_chunks_to_spi_buf(struct oa_tc6 *tc6, u16 needed_empty_chunks) { __be32 header; header = oa_tc6_prepare_data_header(OA_TC6_DATA_INVALID, OA_TC6_DATA_START_INVALID, OA_TC6_DATA_END_INVALID, 0); while (needed_empty_chunks--) { __be32 *tx_buf = tc6->spi_data_tx_buf + tc6->spi_data_tx_buf_offset; *tx_buf = header; tc6->spi_data_tx_buf_offset += OA_TC6_CHUNK_SIZE; } } static u16 oa_tc6_prepare_spi_tx_buf_for_rx_chunks(struct oa_tc6 *tc6, u16 len) { u16 tx_chunks = len / OA_TC6_CHUNK_SIZE; u16 needed_empty_chunks; /* If there are more chunks to receive than to transmit, we need to add * enough empty tx chunks to allow the reception of the excess rx * chunks. */ if (tx_chunks >= tc6->rx_chunks_available) return len; needed_empty_chunks = tc6->rx_chunks_available - tx_chunks; oa_tc6_add_empty_chunks_to_spi_buf(tc6, needed_empty_chunks); return needed_empty_chunks * OA_TC6_CHUNK_SIZE + len; } static int oa_tc6_try_spi_transfer(struct oa_tc6 *tc6) { int ret; while (true) { u16 spi_len = 0; tc6->spi_data_tx_buf_offset = 0; if (tc6->ongoing_tx_skb || tc6->waiting_tx_skb) spi_len = oa_tc6_prepare_spi_tx_buf_for_tx_skbs(tc6); spi_len = oa_tc6_prepare_spi_tx_buf_for_rx_chunks(tc6, spi_len); if (tc6->int_flag) { tc6->int_flag = false; if (spi_len == 0) { oa_tc6_add_empty_chunks_to_spi_buf(tc6, 1); spi_len = OA_TC6_CHUNK_SIZE; } } if (spi_len == 0) break; ret = oa_tc6_spi_transfer(tc6, OA_TC6_DATA_HEADER, spi_len); if (ret) { netdev_err(tc6->netdev, "SPI data transfer failed: %d\n", ret); return ret; } ret = oa_tc6_process_spi_data_rx_buf(tc6, spi_len); if (ret) { if (ret == -EAGAIN) continue; oa_tc6_cleanup_ongoing_tx_skb(tc6); oa_tc6_cleanup_ongoing_rx_skb(tc6); netdev_err(tc6->netdev, "Device error: %d\n", ret); return ret; } if (!tc6->waiting_tx_skb && netif_queue_stopped(tc6->netdev)) netif_wake_queue(tc6->netdev); } return 0; } static int oa_tc6_spi_thread_handler(void *data) { struct oa_tc6 *tc6 = data; int ret; while (likely(!kthread_should_stop())) { /* This kthread will be waken up if there is a tx skb or mac-phy * interrupt to perform spi transfer with tx chunks. */ wait_event_interruptible(tc6->spi_wq, tc6->waiting_tx_skb || tc6->int_flag || kthread_should_stop()); if (kthread_should_stop()) break; ret = oa_tc6_try_spi_transfer(tc6); if (ret) return ret; } return 0; } static int oa_tc6_update_buffer_status_from_register(struct oa_tc6 *tc6) { u32 value; int ret; /* Initially tx credits and rx chunks available to be updated from the * register as there is no data transfer performed yet. Later they will * be updated from the rx footer. */ ret = oa_tc6_read_register(tc6, OA_TC6_REG_BUFFER_STATUS, &value); if (ret) return ret; tc6->tx_credits = FIELD_GET(BUFFER_STATUS_TX_CREDITS_AVAILABLE, value); tc6->rx_chunks_available = FIELD_GET(BUFFER_STATUS_RX_CHUNKS_AVAILABLE, value); return 0; } static irqreturn_t oa_tc6_macphy_isr(int irq, void *data) { struct oa_tc6 *tc6 = data; /* MAC-PHY interrupt can occur for the following reasons. * - availability of tx credits if it was 0 before and not reported in * the previous rx footer. * - availability of rx chunks if it was 0 before and not reported in * the previous rx footer. * - extended status event not reported in the previous rx footer. */ tc6->int_flag = true; /* Wake spi kthread to perform spi transfer */ wake_up_interruptible(&tc6->spi_wq); return IRQ_HANDLED; } /** * oa_tc6_zero_align_receive_frame_enable - function to enable zero align * receive frame feature. * @tc6: oa_tc6 struct. * * Return: 0 on success otherwise failed. */ int oa_tc6_zero_align_receive_frame_enable(struct oa_tc6 *tc6) { u32 regval; int ret; ret = oa_tc6_read_register(tc6, OA_TC6_REG_CONFIG0, ®val); if (ret) return ret; /* Set Zero-Align Receive Frame Enable */ regval |= CONFIG0_ZARFE_ENABLE; return oa_tc6_write_register(tc6, OA_TC6_REG_CONFIG0, regval); } EXPORT_SYMBOL_GPL(oa_tc6_zero_align_receive_frame_enable); /** * oa_tc6_start_xmit - function for sending the tx skb which consists ethernet * frame. * @tc6: oa_tc6 struct. * @skb: socket buffer in which the ethernet frame is stored. * * Return: NETDEV_TX_OK if the transmit ethernet frame skb added in the tx_skb_q * otherwise returns NETDEV_TX_BUSY. */ netdev_tx_t oa_tc6_start_xmit(struct oa_tc6 *tc6, struct sk_buff *skb) { if (tc6->waiting_tx_skb) { netif_stop_queue(tc6->netdev); return NETDEV_TX_BUSY; } if (skb_linearize(skb)) { dev_kfree_skb_any(skb); tc6->netdev->stats.tx_dropped++; return NETDEV_TX_OK; } tc6->waiting_tx_skb = skb; /* Wake spi kthread to perform spi transfer */ wake_up_interruptible(&tc6->spi_wq); return NETDEV_TX_OK; } EXPORT_SYMBOL_GPL(oa_tc6_start_xmit); /** * 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 net_device *netdev) { struct oa_tc6 *tc6; int ret; tc6 = devm_kzalloc(&spi->dev, sizeof(*tc6), GFP_KERNEL); if (!tc6) 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 */ 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; tc6->spi_data_tx_buf = devm_kzalloc(&tc6->spi->dev, OA_TC6_SPI_DATA_BUF_SIZE, GFP_KERNEL); if (!tc6->spi_data_tx_buf) return NULL; tc6->spi_data_rx_buf = devm_kzalloc(&tc6->spi->dev, OA_TC6_SPI_DATA_BUF_SIZE, GFP_KERNEL); if (!tc6->spi_data_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; } 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; } ret = oa_tc6_phy_init(tc6); if (ret) { dev_err(&tc6->spi->dev, "MAC internal PHY initialization failed: %d\n", ret); return NULL; } ret = oa_tc6_enable_data_transfer(tc6); if (ret) { dev_err(&tc6->spi->dev, "Failed to enable data transfer: %d\n", ret); goto phy_exit; } ret = oa_tc6_update_buffer_status_from_register(tc6); if (ret) { dev_err(&tc6->spi->dev, "Failed to update buffer status: %d\n", ret); goto phy_exit; } init_waitqueue_head(&tc6->spi_wq); tc6->spi_thread = kthread_run(oa_tc6_spi_thread_handler, tc6, "oa-tc6-spi-thread"); if (IS_ERR(tc6->spi_thread)) { dev_err(&tc6->spi->dev, "Failed to create SPI thread\n"); goto phy_exit; } sched_set_fifo(tc6->spi_thread); ret = devm_request_irq(&tc6->spi->dev, tc6->spi->irq, oa_tc6_macphy_isr, IRQF_TRIGGER_FALLING, dev_name(&tc6->spi->dev), tc6); if (ret) { dev_err(&tc6->spi->dev, "Failed to request macphy isr %d\n", ret); goto kthread_stop; } /* oa_tc6_sw_reset_macphy() function resets and clears the MAC-PHY reset * complete status. IRQ is also asserted on reset completion and it is * remain asserted until MAC-PHY receives a data chunk. So performing an * empty data chunk transmission will deassert the IRQ. Refer section * 7.7 and 9.2.8.8 in the OPEN Alliance specification for more details. */ tc6->int_flag = true; wake_up_interruptible(&tc6->spi_wq); return tc6; kthread_stop: kthread_stop(tc6->spi_thread); phy_exit: oa_tc6_phy_exit(tc6); return NULL; } 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); kthread_stop(tc6->spi_thread); dev_kfree_skb_any(tc6->ongoing_tx_skb); dev_kfree_skb_any(tc6->waiting_tx_skb); dev_kfree_skb_any(tc6->rx_skb); } EXPORT_SYMBOL_GPL(oa_tc6_exit); MODULE_DESCRIPTION("OPEN Alliance 10BASE‑T1x MAC‑PHY Serial Interface Lib"); MODULE_AUTHOR("Parthiban Veerasooran "); MODULE_LICENSE("GPL");