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1// SPDX-License-Identifier: GPL-2.0-only2/* drivers/net/ethernet/micrel/ks8851.c3 *4 * Copyright 2009 Simtec Electronics5 * http://www.simtec.co.uk/6 * Ben Dooks <ben@simtec.co.uk>7 */8 9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt10 11#include <linux/interrupt.h>12#include <linux/module.h>13#include <linux/kernel.h>14#include <linux/netdevice.h>15#include <linux/etherdevice.h>16#include <linux/ethtool.h>17#include <linux/cache.h>18#include <linux/crc32.h>19#include <linux/mii.h>20#include <linux/regulator/consumer.h>21 22#include <linux/spi/spi.h>23#include <linux/gpio.h>24#include <linux/of_gpio.h>25#include <linux/of_net.h>26 27#include "ks8851.h"28 29static int msg_enable;30 31/**32 * struct ks8851_net_spi - KS8851 SPI driver private data33 * @lock: Lock to ensure that the device is not accessed when busy.34 * @tx_work: Work queue for tx packets35 * @ks8851: KS8851 driver common private data36 * @spidev: The spi device we're bound to.37 * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.38 * @spi_msg2: pre-setup SPI transfer with two messages, @spi_xfer2.39 * @spi_xfer1: @spi_msg1 SPI transfer structure40 * @spi_xfer2: @spi_msg2 SPI transfer structure41 *42 * The @lock ensures that the chip is protected when certain operations are43 * in progress. When the read or write packet transfer is in progress, most44 * of the chip registers are not ccessible until the transfer is finished and45 * the DMA has been de-asserted.46 */47struct ks8851_net_spi {48 struct ks8851_net ks8851;49 struct mutex lock;50 struct work_struct tx_work;51 struct spi_device *spidev;52 struct spi_message spi_msg1;53 struct spi_message spi_msg2;54 struct spi_transfer spi_xfer1;55 struct spi_transfer spi_xfer2[2];56};57 58#define to_ks8851_spi(ks) container_of((ks), struct ks8851_net_spi, ks8851)59 60/* SPI frame opcodes */61#define KS_SPIOP_RD 0x0062#define KS_SPIOP_WR 0x4063#define KS_SPIOP_RXFIFO 0x8064#define KS_SPIOP_TXFIFO 0xC065 66/* shift for byte-enable data */67#define BYTE_EN(_x) ((_x) << 2)68 69/* turn register number and byte-enable mask into data for start of packet */70#define MK_OP(_byteen, _reg) \71 (BYTE_EN(_byteen) | (_reg) << (8 + 2) | (_reg) >> 6)72 73/**74 * ks8851_lock_spi - register access lock75 * @ks: The chip state76 * @flags: Spinlock flags77 *78 * Claim chip register access lock79 */80static void ks8851_lock_spi(struct ks8851_net *ks, unsigned long *flags)81{82 struct ks8851_net_spi *kss = to_ks8851_spi(ks);83 84 mutex_lock(&kss->lock);85}86 87/**88 * ks8851_unlock_spi - register access unlock89 * @ks: The chip state90 * @flags: Spinlock flags91 *92 * Release chip register access lock93 */94static void ks8851_unlock_spi(struct ks8851_net *ks, unsigned long *flags)95{96 struct ks8851_net_spi *kss = to_ks8851_spi(ks);97 98 mutex_unlock(&kss->lock);99}100 101/* SPI register read/write calls.102 *103 * All these calls issue SPI transactions to access the chip's registers. They104 * all require that the necessary lock is held to prevent accesses when the105 * chip is busy transferring packet data (RX/TX FIFO accesses).106 */107 108/**109 * ks8851_wrreg16_spi - write 16bit register value to chip via SPI110 * @ks: The chip state111 * @reg: The register address112 * @val: The value to write113 *114 * Issue a write to put the value @val into the register specified in @reg.115 */116static void ks8851_wrreg16_spi(struct ks8851_net *ks, unsigned int reg,117 unsigned int val)118{119 struct ks8851_net_spi *kss = to_ks8851_spi(ks);120 struct spi_transfer *xfer = &kss->spi_xfer1;121 struct spi_message *msg = &kss->spi_msg1;122 __le16 txb[2];123 int ret;124 125 txb[0] = cpu_to_le16(MK_OP(reg & 2 ? 0xC : 0x03, reg) | KS_SPIOP_WR);126 txb[1] = cpu_to_le16(val);127 128 xfer->tx_buf = txb;129 xfer->rx_buf = NULL;130 xfer->len = 4;131 132 ret = spi_sync(kss->spidev, msg);133 if (ret < 0)134 netdev_err(ks->netdev, "spi_sync() failed\n");135}136 137/**138 * ks8851_rdreg - issue read register command and return the data139 * @ks: The device state140 * @op: The register address and byte enables in message format.141 * @rxb: The RX buffer to return the result into142 * @rxl: The length of data expected.143 *144 * This is the low level read call that issues the necessary spi message(s)145 * to read data from the register specified in @op.146 */147static void ks8851_rdreg(struct ks8851_net *ks, unsigned int op,148 u8 *rxb, unsigned int rxl)149{150 struct ks8851_net_spi *kss = to_ks8851_spi(ks);151 struct spi_transfer *xfer;152 struct spi_message *msg;153 __le16 *txb = (__le16 *)ks->txd;154 u8 *trx = ks->rxd;155 int ret;156 157 txb[0] = cpu_to_le16(op | KS_SPIOP_RD);158 159 if (kss->spidev->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {160 msg = &kss->spi_msg2;161 xfer = kss->spi_xfer2;162 163 xfer->tx_buf = txb;164 xfer->rx_buf = NULL;165 xfer->len = 2;166 167 xfer++;168 xfer->tx_buf = NULL;169 xfer->rx_buf = trx;170 xfer->len = rxl;171 } else {172 msg = &kss->spi_msg1;173 xfer = &kss->spi_xfer1;174 175 xfer->tx_buf = txb;176 xfer->rx_buf = trx;177 xfer->len = rxl + 2;178 }179 180 ret = spi_sync(kss->spidev, msg);181 if (ret < 0)182 netdev_err(ks->netdev, "read: spi_sync() failed\n");183 else if (kss->spidev->controller->flags & SPI_CONTROLLER_HALF_DUPLEX)184 memcpy(rxb, trx, rxl);185 else186 memcpy(rxb, trx + 2, rxl);187}188 189/**190 * ks8851_rdreg16_spi - read 16 bit register from device via SPI191 * @ks: The chip information192 * @reg: The register address193 *194 * Read a 16bit register from the chip, returning the result195 */196static unsigned int ks8851_rdreg16_spi(struct ks8851_net *ks, unsigned int reg)197{198 __le16 rx = 0;199 200 ks8851_rdreg(ks, MK_OP(reg & 2 ? 0xC : 0x3, reg), (u8 *)&rx, 2);201 return le16_to_cpu(rx);202}203 204/**205 * ks8851_rdfifo_spi - read data from the receive fifo via SPI206 * @ks: The device state.207 * @buff: The buffer address208 * @len: The length of the data to read209 *210 * Issue an RXQ FIFO read command and read the @len amount of data from211 * the FIFO into the buffer specified by @buff.212 */213static void ks8851_rdfifo_spi(struct ks8851_net *ks, u8 *buff, unsigned int len)214{215 struct ks8851_net_spi *kss = to_ks8851_spi(ks);216 struct spi_transfer *xfer = kss->spi_xfer2;217 struct spi_message *msg = &kss->spi_msg2;218 u8 txb[1];219 int ret;220 221 netif_dbg(ks, rx_status, ks->netdev,222 "%s: %d@%p\n", __func__, len, buff);223 224 /* set the operation we're issuing */225 txb[0] = KS_SPIOP_RXFIFO;226 227 xfer->tx_buf = txb;228 xfer->rx_buf = NULL;229 xfer->len = 1;230 231 xfer++;232 xfer->rx_buf = buff;233 xfer->tx_buf = NULL;234 xfer->len = len;235 236 ret = spi_sync(kss->spidev, msg);237 if (ret < 0)238 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);239}240 241/**242 * ks8851_wrfifo_spi - write packet to TX FIFO via SPI243 * @ks: The device state.244 * @txp: The sk_buff to transmit.245 * @irq: IRQ on completion of the packet.246 *247 * Send the @txp to the chip. This means creating the relevant packet header248 * specifying the length of the packet and the other information the chip249 * needs, such as IRQ on completion. Send the header and the packet data to250 * the device.251 */252static void ks8851_wrfifo_spi(struct ks8851_net *ks, struct sk_buff *txp,253 bool irq)254{255 struct ks8851_net_spi *kss = to_ks8851_spi(ks);256 struct spi_transfer *xfer = kss->spi_xfer2;257 struct spi_message *msg = &kss->spi_msg2;258 unsigned int fid = 0;259 int ret;260 261 netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n",262 __func__, txp, txp->len, txp->data, irq);263 264 fid = ks->fid++;265 fid &= TXFR_TXFID_MASK;266 267 if (irq)268 fid |= TXFR_TXIC; /* irq on completion */269 270 /* start header at txb[1] to align txw entries */271 ks->txh.txb[1] = KS_SPIOP_TXFIFO;272 ks->txh.txw[1] = cpu_to_le16(fid);273 ks->txh.txw[2] = cpu_to_le16(txp->len);274 275 xfer->tx_buf = &ks->txh.txb[1];276 xfer->rx_buf = NULL;277 xfer->len = 5;278 279 xfer++;280 xfer->tx_buf = txp->data;281 xfer->rx_buf = NULL;282 xfer->len = ALIGN(txp->len, 4);283 284 ret = spi_sync(kss->spidev, msg);285 if (ret < 0)286 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);287}288 289/**290 * calc_txlen - calculate size of message to send packet291 * @len: Length of data292 *293 * Returns the size of the TXFIFO message needed to send294 * this packet.295 */296static unsigned int calc_txlen(unsigned int len)297{298 return ALIGN(len + 4, 4);299}300 301/**302 * ks8851_tx_work - process tx packet(s)303 * @work: The work strucutre what was scheduled.304 *305 * This is called when a number of packets have been scheduled for306 * transmission and need to be sent to the device.307 */308static void ks8851_tx_work(struct work_struct *work)309{310 unsigned int dequeued_len = 0;311 struct ks8851_net_spi *kss;312 unsigned short tx_space;313 struct ks8851_net *ks;314 unsigned long flags;315 struct sk_buff *txb;316 bool last;317 318 kss = container_of(work, struct ks8851_net_spi, tx_work);319 ks = &kss->ks8851;320 last = skb_queue_empty(&ks->txq);321 322 ks8851_lock_spi(ks, &flags);323 324 while (!last) {325 txb = skb_dequeue(&ks->txq);326 last = skb_queue_empty(&ks->txq);327 328 if (txb) {329 dequeued_len += calc_txlen(txb->len);330 331 ks8851_wrreg16_spi(ks, KS_RXQCR,332 ks->rc_rxqcr | RXQCR_SDA);333 ks8851_wrfifo_spi(ks, txb, last);334 ks8851_wrreg16_spi(ks, KS_RXQCR, ks->rc_rxqcr);335 ks8851_wrreg16_spi(ks, KS_TXQCR, TXQCR_METFE);336 337 ks8851_done_tx(ks, txb);338 }339 }340 341 tx_space = ks8851_rdreg16_spi(ks, KS_TXMIR);342 343 spin_lock_bh(&ks->statelock);344 ks->queued_len -= dequeued_len;345 ks->tx_space = tx_space;346 spin_unlock_bh(&ks->statelock);347 348 ks8851_unlock_spi(ks, &flags);349}350 351/**352 * ks8851_flush_tx_work_spi - flush outstanding TX work353 * @ks: The device state354 */355static void ks8851_flush_tx_work_spi(struct ks8851_net *ks)356{357 struct ks8851_net_spi *kss = to_ks8851_spi(ks);358 359 flush_work(&kss->tx_work);360}361 362/**363 * ks8851_start_xmit_spi - transmit packet using SPI364 * @skb: The buffer to transmit365 * @dev: The device used to transmit the packet.366 *367 * Called by the network layer to transmit the @skb. Queue the packet for368 * the device and schedule the necessary work to transmit the packet when369 * it is free.370 *371 * We do this to firstly avoid sleeping with the network device locked,372 * and secondly so we can round up more than one packet to transmit which373 * means we can try and avoid generating too many transmit done interrupts.374 */375static netdev_tx_t ks8851_start_xmit_spi(struct sk_buff *skb,376 struct net_device *dev)377{378 unsigned int needed = calc_txlen(skb->len);379 struct ks8851_net *ks = netdev_priv(dev);380 netdev_tx_t ret = NETDEV_TX_OK;381 struct ks8851_net_spi *kss;382 383 kss = to_ks8851_spi(ks);384 385 netif_dbg(ks, tx_queued, ks->netdev,386 "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);387 388 spin_lock(&ks->statelock);389 390 if (ks->queued_len + needed > ks->tx_space) {391 netif_stop_queue(dev);392 ret = NETDEV_TX_BUSY;393 } else {394 ks->queued_len += needed;395 skb_queue_tail(&ks->txq, skb);396 }397 398 spin_unlock(&ks->statelock);399 if (ret == NETDEV_TX_OK)400 schedule_work(&kss->tx_work);401 402 return ret;403}404 405static int ks8851_probe_spi(struct spi_device *spi)406{407 struct device *dev = &spi->dev;408 struct ks8851_net_spi *kss;409 struct net_device *netdev;410 struct ks8851_net *ks;411 412 netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_spi));413 if (!netdev)414 return -ENOMEM;415 416 spi->bits_per_word = 8;417 418 kss = netdev_priv(netdev);419 ks = &kss->ks8851;420 421 ks->lock = ks8851_lock_spi;422 ks->unlock = ks8851_unlock_spi;423 ks->rdreg16 = ks8851_rdreg16_spi;424 ks->wrreg16 = ks8851_wrreg16_spi;425 ks->rdfifo = ks8851_rdfifo_spi;426 ks->wrfifo = ks8851_wrfifo_spi;427 ks->start_xmit = ks8851_start_xmit_spi;428 ks->flush_tx_work = ks8851_flush_tx_work_spi;429 430#define STD_IRQ (IRQ_LCI | /* Link Change */ \431 IRQ_TXI | /* TX done */ \432 IRQ_RXI | /* RX done */ \433 IRQ_SPIBEI | /* SPI bus error */ \434 IRQ_TXPSI | /* TX process stop */ \435 IRQ_RXPSI) /* RX process stop */436 ks->rc_ier = STD_IRQ;437 438 kss->spidev = spi;439 mutex_init(&kss->lock);440 INIT_WORK(&kss->tx_work, ks8851_tx_work);441 442 /* initialise pre-made spi transfer messages */443 spi_message_init(&kss->spi_msg1);444 spi_message_add_tail(&kss->spi_xfer1, &kss->spi_msg1);445 446 spi_message_init(&kss->spi_msg2);447 spi_message_add_tail(&kss->spi_xfer2[0], &kss->spi_msg2);448 spi_message_add_tail(&kss->spi_xfer2[1], &kss->spi_msg2);449 450 netdev->irq = spi->irq;451 452 return ks8851_probe_common(netdev, dev, msg_enable);453}454 455static void ks8851_remove_spi(struct spi_device *spi)456{457 ks8851_remove_common(&spi->dev);458}459 460static const struct of_device_id ks8851_match_table[] = {461 { .compatible = "micrel,ks8851" },462 { }463};464MODULE_DEVICE_TABLE(of, ks8851_match_table);465 466static struct spi_driver ks8851_driver = {467 .driver = {468 .name = "ks8851",469 .of_match_table = ks8851_match_table,470 .pm = &ks8851_pm_ops,471 },472 .probe = ks8851_probe_spi,473 .remove = ks8851_remove_spi,474};475module_spi_driver(ks8851_driver);476 477MODULE_DESCRIPTION("KS8851 Network driver");478MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");479MODULE_LICENSE("GPL");480 481module_param_named(message, msg_enable, int, 0);482MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)");483MODULE_ALIAS("spi:ks8851");484