// 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 "ks8851.h" static int msg_enable; #define BE3 0x8000 /* Byte Enable 3 */ #define BE2 0x4000 /* Byte Enable 2 */ #define BE1 0x2000 /* Byte Enable 1 */ #define BE0 0x1000 /* Byte Enable 0 */ /** * struct ks8851_net_par - KS8851 Parallel driver private data * @ks8851: KS8851 driver common private data * @lock: Lock to ensure that the device is not accessed when busy. * @hw_addr : start address of data register. * @hw_addr_cmd : start address of command register. * @cmd_reg_cache : command register cached. * * 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 accessible until the transfer is finished * and the DMA has been de-asserted. */ struct ks8851_net_par { struct ks8851_net ks8851; spinlock_t lock; void __iomem *hw_addr; void __iomem *hw_addr_cmd; u16 cmd_reg_cache; }; #define to_ks8851_par(ks) container_of((ks), struct ks8851_net_par, ks8851) /** * ks8851_lock_par - register access lock * @ks: The chip state * @flags: Spinlock flags * * Claim chip register access lock */ static void ks8851_lock_par(struct ks8851_net *ks, unsigned long *flags) { struct ks8851_net_par *ksp = to_ks8851_par(ks); spin_lock_irqsave(&ksp->lock, *flags); } /** * ks8851_unlock_par - register access unlock * @ks: The chip state * @flags: Spinlock flags * * Release chip register access lock */ static void ks8851_unlock_par(struct ks8851_net *ks, unsigned long *flags) { struct ks8851_net_par *ksp = to_ks8851_par(ks); spin_unlock_irqrestore(&ksp->lock, *flags); } /** * ks_check_endian - Check whether endianness of the bus is correct * @ks : The chip information * * The KS8851-16MLL EESK pin allows selecting the endianness of the 16bit * bus. To maintain optimum performance, the bus endianness should be set * such that it matches the endianness of the CPU. */ static int ks_check_endian(struct ks8851_net *ks) { struct ks8851_net_par *ksp = to_ks8851_par(ks); u16 cider; /* * Read CIDER register first, however read it the "wrong" way around. * If the endian strap on the KS8851-16MLL in incorrect and the chip * is operating in different endianness than the CPU, then the meaning * of BE[3:0] byte-enable bits is also swapped such that: * BE[3,2,1,0] becomes BE[1,0,3,2] * * Luckily for us, the byte-enable bits are the top four MSbits of * the address register and the CIDER register is at offset 0xc0. * Hence, by reading address 0xc0c0, which is not impacted by endian * swapping, we assert either BE[3:2] or BE[1:0] while reading the * CIDER register. * * If the bus configuration is correct, reading 0xc0c0 asserts * BE[3:2] and this read returns 0x0000, because to read register * with bottom two LSbits of address set to 0, BE[1:0] must be * asserted. * * If the bus configuration is NOT correct, reading 0xc0c0 asserts * BE[1:0] and this read returns non-zero 0x8872 value. */ iowrite16(BE3 | BE2 | KS_CIDER, ksp->hw_addr_cmd); cider = ioread16(ksp->hw_addr); if (!cider) return 0; netdev_err(ks->netdev, "incorrect EESK endian strap setting\n"); return -EINVAL; } /** * ks8851_wrreg16_par - write 16bit register value to chip * @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_par(struct ks8851_net *ks, unsigned int reg, unsigned int val) { struct ks8851_net_par *ksp = to_ks8851_par(ks); ksp->cmd_reg_cache = (u16)reg | ((BE1 | BE0) << (reg & 0x02)); iowrite16(ksp->cmd_reg_cache, ksp->hw_addr_cmd); iowrite16(val, ksp->hw_addr); } /** * ks8851_rdreg16_par - read 16 bit register from chip * @ks: The chip information * @reg: The register address * * Read a 16bit register from the chip, returning the result */ static unsigned int ks8851_rdreg16_par(struct ks8851_net *ks, unsigned int reg) { struct ks8851_net_par *ksp = to_ks8851_par(ks); ksp->cmd_reg_cache = (u16)reg | ((BE1 | BE0) << (reg & 0x02)); iowrite16(ksp->cmd_reg_cache, ksp->hw_addr_cmd); return ioread16(ksp->hw_addr); } /** * ks8851_rdfifo_par - read data from the receive fifo * @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_par(struct ks8851_net *ks, u8 *buff, unsigned int len) { struct ks8851_net_par *ksp = to_ks8851_par(ks); netif_dbg(ks, rx_status, ks->netdev, "%s: %d@%p\n", __func__, len, buff); ioread16_rep(ksp->hw_addr, (u16 *)buff + 1, len / 2); } /** * ks8851_wrfifo_par - write packet to TX FIFO * @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_par(struct ks8851_net *ks, struct sk_buff *txp, bool irq) { struct ks8851_net_par *ksp = to_ks8851_par(ks); unsigned int len = ALIGN(txp->len, 4); unsigned int fid = 0; 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 */ iowrite16(fid, ksp->hw_addr); iowrite16(txp->len, ksp->hw_addr); iowrite16_rep(ksp->hw_addr, txp->data, len / 2); } /** * ks8851_rx_skb_par - receive skbuff * @ks: The device state. * @skb: The skbuff */ static void ks8851_rx_skb_par(struct ks8851_net *ks, struct sk_buff *skb) { netif_rx(skb); } static unsigned int ks8851_rdreg16_par_txqcr(struct ks8851_net *ks) { return ks8851_rdreg16_par(ks, KS_TXQCR); } /** * ks8851_start_xmit_par - transmit packet * @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_par(struct sk_buff *skb, struct net_device *dev) { struct ks8851_net *ks = netdev_priv(dev); netdev_tx_t ret = NETDEV_TX_OK; unsigned long flags; unsigned int txqcr; u16 txmir; int err; netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data); ks8851_lock_par(ks, &flags); txmir = ks8851_rdreg16_par(ks, KS_TXMIR) & 0x1fff; if (likely(txmir >= skb->len + 12)) { ks8851_wrreg16_par(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA); ks8851_wrfifo_par(ks, skb, false); ks8851_wrreg16_par(ks, KS_RXQCR, ks->rc_rxqcr); ks8851_wrreg16_par(ks, KS_TXQCR, TXQCR_METFE); err = readx_poll_timeout_atomic(ks8851_rdreg16_par_txqcr, ks, txqcr, !(txqcr & TXQCR_METFE), 5, 1000000); if (err) ret = NETDEV_TX_BUSY; ks8851_done_tx(ks, skb); } else { ret = NETDEV_TX_BUSY; } ks8851_unlock_par(ks, &flags); return ret; } static int ks8851_probe_par(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct ks8851_net_par *ksp; struct net_device *netdev; struct ks8851_net *ks; int ret; netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_par)); if (!netdev) return -ENOMEM; ks = netdev_priv(netdev); ks->lock = ks8851_lock_par; ks->unlock = ks8851_unlock_par; ks->rdreg16 = ks8851_rdreg16_par; ks->wrreg16 = ks8851_wrreg16_par; ks->rdfifo = ks8851_rdfifo_par; ks->wrfifo = ks8851_wrfifo_par; ks->start_xmit = ks8851_start_xmit_par; ks->rx_skb = ks8851_rx_skb_par; #define STD_IRQ (IRQ_LCI | /* Link Change */ \ IRQ_RXI | /* RX done */ \ IRQ_RXPSI) /* RX process stop */ ks->rc_ier = STD_IRQ; ksp = to_ks8851_par(ks); spin_lock_init(&ksp->lock); ksp->hw_addr = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(ksp->hw_addr)) return PTR_ERR(ksp->hw_addr); ksp->hw_addr_cmd = devm_platform_ioremap_resource(pdev, 1); if (IS_ERR(ksp->hw_addr_cmd)) return PTR_ERR(ksp->hw_addr_cmd); ret = ks_check_endian(ks); if (ret) return ret; netdev->irq = platform_get_irq(pdev, 0); if (netdev->irq < 0) return netdev->irq; return ks8851_probe_common(netdev, dev, msg_enable); } static int ks8851_remove_par(struct platform_device *pdev) { return ks8851_remove_common(&pdev->dev); } static const struct of_device_id ks8851_match_table[] = { { .compatible = "micrel,ks8851-mll" }, { } }; MODULE_DEVICE_TABLE(of, ks8851_match_table); static struct platform_driver ks8851_driver = { .driver = { .name = "ks8851", .of_match_table = ks8851_match_table, .pm = &ks8851_pm_ops, }, .probe = ks8851_probe_par, .remove = ks8851_remove_par, }; module_platform_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)");