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path: root/drivers/net/ethernet/micrel/ks8851_spi.c
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Diffstat (limited to 'drivers/net/ethernet/micrel/ks8851_spi.c')
-rw-r--r--drivers/net/ethernet/micrel/ks8851_spi.c485
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");