// SPDX-License-Identifier: GPL-2.0-only /* drivers/net/ethernet/micrel/ks8851.c * * Copyright 2009 Simtec Electronics * http://www.simtec.co.uk/ * Ben Dooks */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #define DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ks8851.h" static int msg_enable; /** * struct ks8851_net_spi - KS8851 SPI driver private data * @lock: Lock to ensure that the device is not accessed when busy. * @tx_work: Work queue for tx packets * @ks8851: KS8851 driver common private data * @spidev: The spi device we're bound to. * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1. * @spi_msg2: pre-setup SPI transfer with two messages, @spi_xfer2. * @spi_xfer1: @spi_msg1 SPI transfer structure * @spi_xfer2: @spi_msg2 SPI transfer structure * * The @lock ensures that the chip is protected when certain operations are * in progress. When the read or write packet transfer is in progress, most * of the chip registers are not ccessible until the transfer is finished and * the DMA has been de-asserted. */ struct ks8851_net_spi { struct ks8851_net ks8851; struct mutex lock; struct work_struct tx_work; struct spi_device *spidev; struct spi_message spi_msg1; struct spi_message spi_msg2; struct spi_transfer spi_xfer1; struct spi_transfer spi_xfer2[2]; }; #define to_ks8851_spi(ks) container_of((ks), struct ks8851_net_spi, ks8851) /* SPI frame opcodes */ #define KS_SPIOP_RD 0x00 #define KS_SPIOP_WR 0x40 #define KS_SPIOP_RXFIFO 0x80 #define KS_SPIOP_TXFIFO 0xC0 /* shift for byte-enable data */ #define BYTE_EN(_x) ((_x) << 2) /* turn register number and byte-enable mask into data for start of packet */ #define MK_OP(_byteen, _reg) \ (BYTE_EN(_byteen) | (_reg) << (8 + 2) | (_reg) >> 6) /** * ks8851_lock_spi - register access lock * @ks: The chip state * @flags: Spinlock flags * * Claim chip register access lock */ static void ks8851_lock_spi(struct ks8851_net *ks, unsigned long *flags) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); mutex_lock(&kss->lock); } /** * ks8851_unlock_spi - register access unlock * @ks: The chip state * @flags: Spinlock flags * * Release chip register access lock */ static void ks8851_unlock_spi(struct ks8851_net *ks, unsigned long *flags) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); mutex_unlock(&kss->lock); } /* SPI register read/write calls. * * All these calls issue SPI transactions to access the chip's registers. They * all require that the necessary lock is held to prevent accesses when the * chip is busy transferring packet data (RX/TX FIFO accesses). */ /** * ks8851_wrreg16_spi - write 16bit register value to chip via SPI * @ks: The chip state * @reg: The register address * @val: The value to write * * Issue a write to put the value @val into the register specified in @reg. */ static void ks8851_wrreg16_spi(struct ks8851_net *ks, unsigned int reg, unsigned int val) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); struct spi_transfer *xfer = &kss->spi_xfer1; struct spi_message *msg = &kss->spi_msg1; __le16 txb[2]; int ret; txb[0] = cpu_to_le16(MK_OP(reg & 2 ? 0xC : 0x03, reg) | KS_SPIOP_WR); txb[1] = cpu_to_le16(val); xfer->tx_buf = txb; xfer->rx_buf = NULL; xfer->len = 4; ret = spi_sync(kss->spidev, msg); if (ret < 0) netdev_err(ks->netdev, "spi_sync() failed\n"); } /** * ks8851_rdreg - issue read register command and return the data * @ks: The device state * @op: The register address and byte enables in message format. * @rxb: The RX buffer to return the result into * @rxl: The length of data expected. * * This is the low level read call that issues the necessary spi message(s) * to read data from the register specified in @op. */ static void ks8851_rdreg(struct ks8851_net *ks, unsigned int op, u8 *rxb, unsigned int rxl) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); struct spi_transfer *xfer; struct spi_message *msg; __le16 *txb = (__le16 *)ks->txd; u8 *trx = ks->rxd; int ret; txb[0] = cpu_to_le16(op | KS_SPIOP_RD); if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX) { msg = &kss->spi_msg2; xfer = kss->spi_xfer2; xfer->tx_buf = txb; xfer->rx_buf = NULL; xfer->len = 2; xfer++; xfer->tx_buf = NULL; xfer->rx_buf = trx; xfer->len = rxl; } else { msg = &kss->spi_msg1; xfer = &kss->spi_xfer1; xfer->tx_buf = txb; xfer->rx_buf = trx; xfer->len = rxl + 2; } ret = spi_sync(kss->spidev, msg); if (ret < 0) netdev_err(ks->netdev, "read: spi_sync() failed\n"); else if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX) memcpy(rxb, trx, rxl); else memcpy(rxb, trx + 2, rxl); } /** * ks8851_rdreg16_spi - read 16 bit register from device via SPI * @ks: The chip information * @reg: The register address * * Read a 16bit register from the chip, returning the result */ static unsigned int ks8851_rdreg16_spi(struct ks8851_net *ks, unsigned int reg) { __le16 rx = 0; ks8851_rdreg(ks, MK_OP(reg & 2 ? 0xC : 0x3, reg), (u8 *)&rx, 2); return le16_to_cpu(rx); } /** * ks8851_rdfifo_spi - read data from the receive fifo via SPI * @ks: The device state. * @buff: The buffer address * @len: The length of the data to read * * Issue an RXQ FIFO read command and read the @len amount of data from * the FIFO into the buffer specified by @buff. */ static void ks8851_rdfifo_spi(struct ks8851_net *ks, u8 *buff, unsigned int len) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); struct spi_transfer *xfer = kss->spi_xfer2; struct spi_message *msg = &kss->spi_msg2; u8 txb[1]; int ret; netif_dbg(ks, rx_status, ks->netdev, "%s: %d@%p\n", __func__, len, buff); /* set the operation we're issuing */ txb[0] = KS_SPIOP_RXFIFO; xfer->tx_buf = txb; xfer->rx_buf = NULL; xfer->len = 1; xfer++; xfer->rx_buf = buff; xfer->tx_buf = NULL; xfer->len = len; ret = spi_sync(kss->spidev, msg); if (ret < 0) netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__); } /** * ks8851_wrfifo_spi - write packet to TX FIFO via SPI * @ks: The device state. * @txp: The sk_buff to transmit. * @irq: IRQ on completion of the packet. * * Send the @txp to the chip. This means creating the relevant packet header * specifying the length of the packet and the other information the chip * needs, such as IRQ on completion. Send the header and the packet data to * the device. */ static void ks8851_wrfifo_spi(struct ks8851_net *ks, struct sk_buff *txp, bool irq) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); struct spi_transfer *xfer = kss->spi_xfer2; struct spi_message *msg = &kss->spi_msg2; unsigned int fid = 0; int ret; netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n", __func__, txp, txp->len, txp->data, irq); fid = ks->fid++; fid &= TXFR_TXFID_MASK; if (irq) fid |= TXFR_TXIC; /* irq on completion */ /* start header at txb[1] to align txw entries */ ks->txh.txb[1] = KS_SPIOP_TXFIFO; ks->txh.txw[1] = cpu_to_le16(fid); ks->txh.txw[2] = cpu_to_le16(txp->len); xfer->tx_buf = &ks->txh.txb[1]; xfer->rx_buf = NULL; xfer->len = 5; xfer++; xfer->tx_buf = txp->data; xfer->rx_buf = NULL; xfer->len = ALIGN(txp->len, 4); ret = spi_sync(kss->spidev, msg); if (ret < 0) netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__); } /** * calc_txlen - calculate size of message to send packet * @len: Length of data * * Returns the size of the TXFIFO message needed to send * this packet. */ static unsigned int calc_txlen(unsigned int len) { return ALIGN(len + 4, 4); } /** * ks8851_rx_skb_spi - receive skbuff * @ks: The device state * @skb: The skbuff */ static void ks8851_rx_skb_spi(struct ks8851_net *ks, struct sk_buff *skb) { netif_rx_ni(skb); } /** * ks8851_tx_work - process tx packet(s) * @work: The work strucutre what was scheduled. * * This is called when a number of packets have been scheduled for * transmission and need to be sent to the device. */ static void ks8851_tx_work(struct work_struct *work) { unsigned int dequeued_len = 0; struct ks8851_net_spi *kss; unsigned short tx_space; struct ks8851_net *ks; unsigned long flags; struct sk_buff *txb; bool last; kss = container_of(work, struct ks8851_net_spi, tx_work); ks = &kss->ks8851; last = skb_queue_empty(&ks->txq); ks8851_lock_spi(ks, &flags); while (!last) { txb = skb_dequeue(&ks->txq); last = skb_queue_empty(&ks->txq); if (txb) { dequeued_len += calc_txlen(txb->len); ks8851_wrreg16_spi(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA); ks8851_wrfifo_spi(ks, txb, last); ks8851_wrreg16_spi(ks, KS_RXQCR, ks->rc_rxqcr); ks8851_wrreg16_spi(ks, KS_TXQCR, TXQCR_METFE); ks8851_done_tx(ks, txb); } } tx_space = ks8851_rdreg16_spi(ks, KS_TXMIR); spin_lock(&ks->statelock); ks->queued_len -= dequeued_len; ks->tx_space = tx_space; spin_unlock(&ks->statelock); ks8851_unlock_spi(ks, &flags); } /** * ks8851_flush_tx_work_spi - flush outstanding TX work * @ks: The device state */ static void ks8851_flush_tx_work_spi(struct ks8851_net *ks) { struct ks8851_net_spi *kss = to_ks8851_spi(ks); flush_work(&kss->tx_work); } /** * ks8851_start_xmit_spi - transmit packet using SPI * @skb: The buffer to transmit * @dev: The device used to transmit the packet. * * Called by the network layer to transmit the @skb. Queue the packet for * the device and schedule the necessary work to transmit the packet when * it is free. * * We do this to firstly avoid sleeping with the network device locked, * and secondly so we can round up more than one packet to transmit which * means we can try and avoid generating too many transmit done interrupts. */ static netdev_tx_t ks8851_start_xmit_spi(struct sk_buff *skb, struct net_device *dev) { unsigned int needed = calc_txlen(skb->len); struct ks8851_net *ks = netdev_priv(dev); netdev_tx_t ret = NETDEV_TX_OK; struct ks8851_net_spi *kss; kss = to_ks8851_spi(ks); netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data); spin_lock(&ks->statelock); if (ks->queued_len + needed > ks->tx_space) { netif_stop_queue(dev); ret = NETDEV_TX_BUSY; } else { ks->queued_len += needed; skb_queue_tail(&ks->txq, skb); } spin_unlock(&ks->statelock); if (ret == NETDEV_TX_OK) schedule_work(&kss->tx_work); return ret; } static int ks8851_probe_spi(struct spi_device *spi) { struct device *dev = &spi->dev; struct ks8851_net_spi *kss; struct net_device *netdev; struct ks8851_net *ks; netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_spi)); if (!netdev) return -ENOMEM; spi->bits_per_word = 8; ks = netdev_priv(netdev); ks->lock = ks8851_lock_spi; ks->unlock = ks8851_unlock_spi; ks->rdreg16 = ks8851_rdreg16_spi; ks->wrreg16 = ks8851_wrreg16_spi; ks->rdfifo = ks8851_rdfifo_spi; ks->wrfifo = ks8851_wrfifo_spi; ks->start_xmit = ks8851_start_xmit_spi; ks->rx_skb = ks8851_rx_skb_spi; ks->flush_tx_work = ks8851_flush_tx_work_spi; #define STD_IRQ (IRQ_LCI | /* Link Change */ \ IRQ_TXI | /* TX done */ \ IRQ_RXI | /* RX done */ \ IRQ_SPIBEI | /* SPI bus error */ \ IRQ_TXPSI | /* TX process stop */ \ IRQ_RXPSI) /* RX process stop */ ks->rc_ier = STD_IRQ; kss = to_ks8851_spi(ks); kss->spidev = spi; mutex_init(&kss->lock); INIT_WORK(&kss->tx_work, ks8851_tx_work); /* initialise pre-made spi transfer messages */ spi_message_init(&kss->spi_msg1); spi_message_add_tail(&kss->spi_xfer1, &kss->spi_msg1); spi_message_init(&kss->spi_msg2); spi_message_add_tail(&kss->spi_xfer2[0], &kss->spi_msg2); spi_message_add_tail(&kss->spi_xfer2[1], &kss->spi_msg2); netdev->irq = spi->irq; return ks8851_probe_common(netdev, dev, msg_enable); } static int ks8851_remove_spi(struct spi_device *spi) { return ks8851_remove_common(&spi->dev); } static const struct of_device_id ks8851_match_table[] = { { .compatible = "micrel,ks8851" }, { } }; MODULE_DEVICE_TABLE(of, ks8851_match_table); static struct spi_driver ks8851_driver = { .driver = { .name = "ks8851", .of_match_table = ks8851_match_table, .pm = &ks8851_pm_ops, }, .probe = ks8851_probe_spi, .remove = ks8851_remove_spi, }; module_spi_driver(ks8851_driver); MODULE_DESCRIPTION("KS8851 Network driver"); MODULE_AUTHOR("Ben Dooks "); MODULE_LICENSE("GPL"); module_param_named(message, msg_enable, int, 0); MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)"); MODULE_ALIAS("spi:ks8851");