diff options
Diffstat (limited to 'drivers/net/ethernet/micrel/ks8851_spi.c')
-rw-r--r-- | drivers/net/ethernet/micrel/ks8851_spi.c | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/drivers/net/ethernet/micrel/ks8851_spi.c b/drivers/net/ethernet/micrel/ks8851_spi.c new file mode 100644 index 000000000000..4ec7f1615977 --- /dev/null +++ b/drivers/net/ethernet/micrel/ks8851_spi.c @@ -0,0 +1,485 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* drivers/net/ethernet/micrel/ks8851.c + * + * Copyright 2009 Simtec Electronics + * http://www.simtec.co.uk/ + * Ben Dooks <ben@simtec.co.uk> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#define DEBUG + +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/ethtool.h> +#include <linux/cache.h> +#include <linux/crc32.h> +#include <linux/mii.h> +#include <linux/regulator/consumer.h> + +#include <linux/spi/spi.h> +#include <linux/gpio.h> +#include <linux/of_gpio.h> +#include <linux/of_net.h> + +#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__); +} + +/** + * 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) +{ + struct ks8851_net_spi *kss; + 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) { + 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); + } + } + + 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); +} + +/** + * 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_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 (needed > ks->tx_space) { + netif_stop_queue(dev); + ret = NETDEV_TX_BUSY; + } else { + ks->tx_space -= needed; + skb_queue_tail(&ks->txq, skb); + } + + spin_unlock(&ks->statelock); + 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 <ben@simtec.co.uk>"); +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"); |