1 // SPDX-License-Identifier: GPL-2.0-only
2 /* drivers/net/ethernet/micrel/ks8851.c
4 * Copyright 2009 Simtec Electronics
5 * http://www.simtec.co.uk/
6 * Ben Dooks <ben@simtec.co.uk>
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/interrupt.h>
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <linux/etherdevice.h>
18 #include <linux/ethtool.h>
19 #include <linux/cache.h>
20 #include <linux/crc32.h>
21 #include <linux/mii.h>
22 #include <linux/regulator/consumer.h>
24 #include <linux/spi/spi.h>
25 #include <linux/gpio.h>
26 #include <linux/of_gpio.h>
27 #include <linux/of_net.h>
31 static int msg_enable;
34 * struct ks8851_net_spi - KS8851 SPI driver private data
35 * @lock: Lock to ensure that the device is not accessed when busy.
36 * @tx_work: Work queue for tx packets
37 * @ks8851: KS8851 driver common private data
38 * @spidev: The spi device we're bound to.
39 * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.
40 * @spi_msg2: pre-setup SPI transfer with two messages, @spi_xfer2.
41 * @spi_xfer1: @spi_msg1 SPI transfer structure
42 * @spi_xfer2: @spi_msg2 SPI transfer structure
44 * The @lock ensures that the chip is protected when certain operations are
45 * in progress. When the read or write packet transfer is in progress, most
46 * of the chip registers are not ccessible until the transfer is finished and
47 * the DMA has been de-asserted.
49 struct ks8851_net_spi {
50 struct ks8851_net ks8851;
52 struct work_struct tx_work;
53 struct spi_device *spidev;
54 struct spi_message spi_msg1;
55 struct spi_message spi_msg2;
56 struct spi_transfer spi_xfer1;
57 struct spi_transfer spi_xfer2[2];
60 #define to_ks8851_spi(ks) container_of((ks), struct ks8851_net_spi, ks8851)
62 /* SPI frame opcodes */
63 #define KS_SPIOP_RD 0x00
64 #define KS_SPIOP_WR 0x40
65 #define KS_SPIOP_RXFIFO 0x80
66 #define KS_SPIOP_TXFIFO 0xC0
68 /* shift for byte-enable data */
69 #define BYTE_EN(_x) ((_x) << 2)
71 /* turn register number and byte-enable mask into data for start of packet */
72 #define MK_OP(_byteen, _reg) \
73 (BYTE_EN(_byteen) | (_reg) << (8 + 2) | (_reg) >> 6)
76 * ks8851_lock_spi - register access lock
78 * @flags: Spinlock flags
80 * Claim chip register access lock
82 static void ks8851_lock_spi(struct ks8851_net *ks, unsigned long *flags)
84 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
86 mutex_lock(&kss->lock);
90 * ks8851_unlock_spi - register access unlock
92 * @flags: Spinlock flags
94 * Release chip register access lock
96 static void ks8851_unlock_spi(struct ks8851_net *ks, unsigned long *flags)
98 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
100 mutex_unlock(&kss->lock);
103 /* SPI register read/write calls.
105 * All these calls issue SPI transactions to access the chip's registers. They
106 * all require that the necessary lock is held to prevent accesses when the
107 * chip is busy transferring packet data (RX/TX FIFO accesses).
111 * ks8851_wrreg16_spi - write 16bit register value to chip via SPI
112 * @ks: The chip state
113 * @reg: The register address
114 * @val: The value to write
116 * Issue a write to put the value @val into the register specified in @reg.
118 static void ks8851_wrreg16_spi(struct ks8851_net *ks, unsigned int reg,
121 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
122 struct spi_transfer *xfer = &kss->spi_xfer1;
123 struct spi_message *msg = &kss->spi_msg1;
127 txb[0] = cpu_to_le16(MK_OP(reg & 2 ? 0xC : 0x03, reg) | KS_SPIOP_WR);
128 txb[1] = cpu_to_le16(val);
134 ret = spi_sync(kss->spidev, msg);
136 netdev_err(ks->netdev, "spi_sync() failed\n");
140 * ks8851_rdreg - issue read register command and return the data
141 * @ks: The device state
142 * @op: The register address and byte enables in message format.
143 * @rxb: The RX buffer to return the result into
144 * @rxl: The length of data expected.
146 * This is the low level read call that issues the necessary spi message(s)
147 * to read data from the register specified in @op.
149 static void ks8851_rdreg(struct ks8851_net *ks, unsigned int op,
150 u8 *rxb, unsigned int rxl)
152 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
153 struct spi_transfer *xfer;
154 struct spi_message *msg;
155 __le16 *txb = (__le16 *)ks->txd;
159 txb[0] = cpu_to_le16(op | KS_SPIOP_RD);
161 if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX) {
162 msg = &kss->spi_msg2;
163 xfer = kss->spi_xfer2;
174 msg = &kss->spi_msg1;
175 xfer = &kss->spi_xfer1;
182 ret = spi_sync(kss->spidev, msg);
184 netdev_err(ks->netdev, "read: spi_sync() failed\n");
185 else if (kss->spidev->master->flags & SPI_MASTER_HALF_DUPLEX)
186 memcpy(rxb, trx, rxl);
188 memcpy(rxb, trx + 2, rxl);
192 * ks8851_rdreg16_spi - read 16 bit register from device via SPI
193 * @ks: The chip information
194 * @reg: The register address
196 * Read a 16bit register from the chip, returning the result
198 static unsigned int ks8851_rdreg16_spi(struct ks8851_net *ks, unsigned int reg)
202 ks8851_rdreg(ks, MK_OP(reg & 2 ? 0xC : 0x3, reg), (u8 *)&rx, 2);
203 return le16_to_cpu(rx);
207 * ks8851_rdfifo_spi - read data from the receive fifo via SPI
208 * @ks: The device state.
209 * @buff: The buffer address
210 * @len: The length of the data to read
212 * Issue an RXQ FIFO read command and read the @len amount of data from
213 * the FIFO into the buffer specified by @buff.
215 static void ks8851_rdfifo_spi(struct ks8851_net *ks, u8 *buff, unsigned int len)
217 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
218 struct spi_transfer *xfer = kss->spi_xfer2;
219 struct spi_message *msg = &kss->spi_msg2;
223 netif_dbg(ks, rx_status, ks->netdev,
224 "%s: %d@%p\n", __func__, len, buff);
226 /* set the operation we're issuing */
227 txb[0] = KS_SPIOP_RXFIFO;
238 ret = spi_sync(kss->spidev, msg);
240 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
244 * ks8851_wrfifo_spi - write packet to TX FIFO via SPI
245 * @ks: The device state.
246 * @txp: The sk_buff to transmit.
247 * @irq: IRQ on completion of the packet.
249 * Send the @txp to the chip. This means creating the relevant packet header
250 * specifying the length of the packet and the other information the chip
251 * needs, such as IRQ on completion. Send the header and the packet data to
254 static void ks8851_wrfifo_spi(struct ks8851_net *ks, struct sk_buff *txp,
257 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
258 struct spi_transfer *xfer = kss->spi_xfer2;
259 struct spi_message *msg = &kss->spi_msg2;
260 unsigned int fid = 0;
263 netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n",
264 __func__, txp, txp->len, txp->data, irq);
267 fid &= TXFR_TXFID_MASK;
270 fid |= TXFR_TXIC; /* irq on completion */
272 /* start header at txb[1] to align txw entries */
273 ks->txh.txb[1] = KS_SPIOP_TXFIFO;
274 ks->txh.txw[1] = cpu_to_le16(fid);
275 ks->txh.txw[2] = cpu_to_le16(txp->len);
277 xfer->tx_buf = &ks->txh.txb[1];
282 xfer->tx_buf = txp->data;
284 xfer->len = ALIGN(txp->len, 4);
286 ret = spi_sync(kss->spidev, msg);
288 netdev_err(ks->netdev, "%s: spi_sync() failed\n", __func__);
292 * calc_txlen - calculate size of message to send packet
293 * @len: Length of data
295 * Returns the size of the TXFIFO message needed to send
298 static unsigned int calc_txlen(unsigned int len)
300 return ALIGN(len + 4, 4);
304 * ks8851_rx_skb_spi - receive skbuff
305 * @ks: The device state
308 static void ks8851_rx_skb_spi(struct ks8851_net *ks, struct sk_buff *skb)
314 * ks8851_tx_work - process tx packet(s)
315 * @work: The work strucutre what was scheduled.
317 * This is called when a number of packets have been scheduled for
318 * transmission and need to be sent to the device.
320 static void ks8851_tx_work(struct work_struct *work)
322 unsigned int dequeued_len = 0;
323 struct ks8851_net_spi *kss;
324 unsigned short tx_space;
325 struct ks8851_net *ks;
330 kss = container_of(work, struct ks8851_net_spi, tx_work);
332 last = skb_queue_empty(&ks->txq);
334 ks8851_lock_spi(ks, &flags);
337 txb = skb_dequeue(&ks->txq);
338 last = skb_queue_empty(&ks->txq);
341 dequeued_len += calc_txlen(txb->len);
343 ks8851_wrreg16_spi(ks, KS_RXQCR,
344 ks->rc_rxqcr | RXQCR_SDA);
345 ks8851_wrfifo_spi(ks, txb, last);
346 ks8851_wrreg16_spi(ks, KS_RXQCR, ks->rc_rxqcr);
347 ks8851_wrreg16_spi(ks, KS_TXQCR, TXQCR_METFE);
349 ks8851_done_tx(ks, txb);
353 tx_space = ks8851_rdreg16_spi(ks, KS_TXMIR);
355 spin_lock(&ks->statelock);
356 ks->queued_len -= dequeued_len;
357 ks->tx_space = tx_space;
358 spin_unlock(&ks->statelock);
360 ks8851_unlock_spi(ks, &flags);
364 * ks8851_flush_tx_work_spi - flush outstanding TX work
365 * @ks: The device state
367 static void ks8851_flush_tx_work_spi(struct ks8851_net *ks)
369 struct ks8851_net_spi *kss = to_ks8851_spi(ks);
371 flush_work(&kss->tx_work);
375 * ks8851_start_xmit_spi - transmit packet using SPI
376 * @skb: The buffer to transmit
377 * @dev: The device used to transmit the packet.
379 * Called by the network layer to transmit the @skb. Queue the packet for
380 * the device and schedule the necessary work to transmit the packet when
383 * We do this to firstly avoid sleeping with the network device locked,
384 * and secondly so we can round up more than one packet to transmit which
385 * means we can try and avoid generating too many transmit done interrupts.
387 static netdev_tx_t ks8851_start_xmit_spi(struct sk_buff *skb,
388 struct net_device *dev)
390 unsigned int needed = calc_txlen(skb->len);
391 struct ks8851_net *ks = netdev_priv(dev);
392 netdev_tx_t ret = NETDEV_TX_OK;
393 struct ks8851_net_spi *kss;
395 kss = to_ks8851_spi(ks);
397 netif_dbg(ks, tx_queued, ks->netdev,
398 "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
400 spin_lock(&ks->statelock);
402 if (ks->queued_len + needed > ks->tx_space) {
403 netif_stop_queue(dev);
404 ret = NETDEV_TX_BUSY;
406 ks->queued_len += needed;
407 skb_queue_tail(&ks->txq, skb);
410 spin_unlock(&ks->statelock);
411 if (ret == NETDEV_TX_OK)
412 schedule_work(&kss->tx_work);
417 static int ks8851_probe_spi(struct spi_device *spi)
419 struct device *dev = &spi->dev;
420 struct ks8851_net_spi *kss;
421 struct net_device *netdev;
422 struct ks8851_net *ks;
424 netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_spi));
428 spi->bits_per_word = 8;
430 ks = netdev_priv(netdev);
432 ks->lock = ks8851_lock_spi;
433 ks->unlock = ks8851_unlock_spi;
434 ks->rdreg16 = ks8851_rdreg16_spi;
435 ks->wrreg16 = ks8851_wrreg16_spi;
436 ks->rdfifo = ks8851_rdfifo_spi;
437 ks->wrfifo = ks8851_wrfifo_spi;
438 ks->start_xmit = ks8851_start_xmit_spi;
439 ks->rx_skb = ks8851_rx_skb_spi;
440 ks->flush_tx_work = ks8851_flush_tx_work_spi;
442 #define STD_IRQ (IRQ_LCI | /* Link Change */ \
443 IRQ_TXI | /* TX done */ \
444 IRQ_RXI | /* RX done */ \
445 IRQ_SPIBEI | /* SPI bus error */ \
446 IRQ_TXPSI | /* TX process stop */ \
447 IRQ_RXPSI) /* RX process stop */
448 ks->rc_ier = STD_IRQ;
450 kss = to_ks8851_spi(ks);
453 mutex_init(&kss->lock);
454 INIT_WORK(&kss->tx_work, ks8851_tx_work);
456 /* initialise pre-made spi transfer messages */
457 spi_message_init(&kss->spi_msg1);
458 spi_message_add_tail(&kss->spi_xfer1, &kss->spi_msg1);
460 spi_message_init(&kss->spi_msg2);
461 spi_message_add_tail(&kss->spi_xfer2[0], &kss->spi_msg2);
462 spi_message_add_tail(&kss->spi_xfer2[1], &kss->spi_msg2);
464 netdev->irq = spi->irq;
466 return ks8851_probe_common(netdev, dev, msg_enable);
469 static int ks8851_remove_spi(struct spi_device *spi)
471 return ks8851_remove_common(&spi->dev);
474 static const struct of_device_id ks8851_match_table[] = {
475 { .compatible = "micrel,ks8851" },
478 MODULE_DEVICE_TABLE(of, ks8851_match_table);
480 static struct spi_driver ks8851_driver = {
483 .of_match_table = ks8851_match_table,
484 .pm = &ks8851_pm_ops,
486 .probe = ks8851_probe_spi,
487 .remove = ks8851_remove_spi,
489 module_spi_driver(ks8851_driver);
491 MODULE_DESCRIPTION("KS8851 Network driver");
492 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
493 MODULE_LICENSE("GPL");
495 module_param_named(message, msg_enable, int, 0);
496 MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)");
497 MODULE_ALIAS("spi:ks8851");