OSCL-LXR linux-6.0.1/​drivers/​net/​ethernet/​micrel/​ks8851_spi.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // 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
 
 #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(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 void ks8851_remove_spi(struct spi_device *spi)
 {
     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");

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