1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2021 in-tech smart charging GmbH
4 * driver is based on micrel/ks8851_spi.c
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/netdevice.h>
13 #include <linux/etherdevice.h>
14 #include <linux/ethtool.h>
15 #include <linux/cache.h>
16 #include <linux/debugfs.h>
17 #include <linux/seq_file.h>
19 #include <linux/spi/spi.h>
20 #include <linux/of_net.h>
22 #define MSG_DEFAULT (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK | \
25 #define DRV_NAME "mse102x"
27 #define DET_CMD 0x0001
28 #define DET_SOF 0x0002
29 #define DET_DFT 0x55AA
32 #define CMD_RTS (0x1 << CMD_SHIFT)
33 #define CMD_CTR (0x2 << CMD_SHIFT)
35 #define CMD_MASK GENMASK(15, CMD_SHIFT)
36 #define LEN_MASK GENMASK(CMD_SHIFT - 1, 0)
42 #define MIN_FREQ_HZ 6000000
43 #define MAX_FREQ_HZ 7142857
45 struct mse102x_stats {
56 static const char mse102x_gstrings_stats[][ETH_GSTRING_LEN] = {
57 "SPI transfer errors",
61 "Invalid frame length",
68 struct net_device *ndev;
73 u32 msg_enable ____cacheline_aligned;
75 struct sk_buff_head txq;
76 struct mse102x_stats stats;
79 struct mse102x_net_spi {
80 struct mse102x_net mse102x;
81 struct mutex lock; /* Protect SPI frame transfer */
82 struct work_struct tx_work;
83 struct spi_device *spidev;
84 struct spi_message spi_msg;
85 struct spi_transfer spi_xfer;
87 #ifdef CONFIG_DEBUG_FS
88 struct dentry *device_root;
92 #define to_mse102x_spi(mse) container_of((mse), struct mse102x_net_spi, mse102x)
94 #ifdef CONFIG_DEBUG_FS
96 static int mse102x_info_show(struct seq_file *s, void *what)
98 struct mse102x_net_spi *mses = s->private;
100 seq_printf(s, "TX ring size : %u\n",
101 skb_queue_len(&mses->mse102x.txq));
103 seq_printf(s, "IRQ : %d\n",
106 seq_printf(s, "SPI effective speed : %lu\n",
107 (unsigned long)mses->spi_xfer.effective_speed_hz);
108 seq_printf(s, "SPI mode : %x\n",
113 DEFINE_SHOW_ATTRIBUTE(mse102x_info);
115 static void mse102x_init_device_debugfs(struct mse102x_net_spi *mses)
117 mses->device_root = debugfs_create_dir(dev_name(&mses->mse102x.ndev->dev),
120 debugfs_create_file("info", S_IFREG | 0444, mses->device_root, mses,
124 static void mse102x_remove_device_debugfs(struct mse102x_net_spi *mses)
126 debugfs_remove_recursive(mses->device_root);
129 #else /* CONFIG_DEBUG_FS */
131 static void mse102x_init_device_debugfs(struct mse102x_net_spi *mses)
135 static void mse102x_remove_device_debugfs(struct mse102x_net_spi *mses)
141 /* SPI register read/write calls.
143 * All these calls issue SPI transactions to access the chip's registers. They
144 * all require that the necessary lock is held to prevent accesses when the
145 * chip is busy transferring packet data.
148 static void mse102x_tx_cmd_spi(struct mse102x_net *mse, u16 cmd)
150 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
151 struct spi_transfer *xfer = &mses->spi_xfer;
152 struct spi_message *msg = &mses->spi_msg;
156 txb[0] = cpu_to_be16(DET_CMD);
157 txb[1] = cpu_to_be16(cmd);
161 xfer->len = DET_CMD_LEN;
163 ret = spi_sync(mses->spidev, msg);
165 netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
167 mse->stats.xfer_err++;
171 static int mse102x_rx_cmd_spi(struct mse102x_net *mse, u8 *rxb)
173 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
174 struct spi_transfer *xfer = &mses->spi_xfer;
175 struct spi_message *msg = &mses->spi_msg;
176 __be16 *txb = (__be16 *)mse->txd;
177 __be16 *cmd = (__be16 *)mse->rxd;
186 xfer->len = DET_CMD_LEN;
188 ret = spi_sync(mses->spidev, msg);
190 netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
192 mse->stats.xfer_err++;
193 } else if (*cmd != cpu_to_be16(DET_CMD)) {
194 net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
196 mse->stats.invalid_cmd++;
199 memcpy(rxb, trx + 2, 2);
205 static inline void mse102x_push_header(struct sk_buff *skb)
207 __be16 *header = skb_push(skb, DET_SOF_LEN);
209 *header = cpu_to_be16(DET_SOF);
212 static inline void mse102x_put_footer(struct sk_buff *skb)
214 __be16 *footer = skb_put(skb, DET_DFT_LEN);
216 *footer = cpu_to_be16(DET_DFT);
219 static int mse102x_tx_frame_spi(struct mse102x_net *mse, struct sk_buff *txp,
222 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
223 struct spi_transfer *xfer = &mses->spi_xfer;
224 struct spi_message *msg = &mses->spi_msg;
225 struct sk_buff *tskb = NULL;
228 netif_dbg(mse, tx_queued, mse->ndev, "%s: skb %p, %d@%p\n",
229 __func__, txp, txp->len, txp->data);
231 if ((skb_headroom(txp) < DET_SOF_LEN) ||
232 (skb_tailroom(txp) < DET_DFT_LEN + pad)) {
233 tskb = skb_copy_expand(txp, DET_SOF_LEN, DET_DFT_LEN + pad,
241 mse102x_push_header(txp);
244 skb_put_zero(txp, pad);
246 mse102x_put_footer(txp);
248 xfer->tx_buf = txp->data;
250 xfer->len = txp->len;
252 ret = spi_sync(mses->spidev, msg);
254 netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
256 mse->stats.xfer_err++;
264 static int mse102x_rx_frame_spi(struct mse102x_net *mse, u8 *buff,
265 unsigned int frame_len)
267 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
268 struct spi_transfer *xfer = &mses->spi_xfer;
269 struct spi_message *msg = &mses->spi_msg;
270 __be16 *sof = (__be16 *)buff;
271 __be16 *dft = (__be16 *)(buff + DET_SOF_LEN + frame_len);
276 xfer->len = DET_SOF_LEN + frame_len + DET_DFT_LEN;
278 ret = spi_sync(mses->spidev, msg);
280 netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
282 mse->stats.xfer_err++;
283 } else if (*sof != cpu_to_be16(DET_SOF)) {
284 netdev_dbg(mse->ndev, "%s: SPI start of frame is invalid (0x%04x)\n",
286 mse->stats.invalid_sof++;
288 } else if (*dft != cpu_to_be16(DET_DFT)) {
289 netdev_dbg(mse->ndev, "%s: SPI frame tail is invalid (0x%04x)\n",
291 mse->stats.invalid_dft++;
298 static void mse102x_dump_packet(const char *msg, int len, const char *data)
300 printk(KERN_DEBUG ": %s - packet len:%d\n", msg, len);
301 print_hex_dump(KERN_DEBUG, "pk data: ", DUMP_PREFIX_OFFSET, 16, 1,
305 static void mse102x_rx_pkt_spi(struct mse102x_net *mse)
308 unsigned int rxalign;
315 mse102x_tx_cmd_spi(mse, CMD_CTR);
316 ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
317 cmd_resp = be16_to_cpu(rx);
319 if (ret || ((cmd_resp & CMD_MASK) != CMD_RTS)) {
320 usleep_range(50, 100);
322 mse102x_tx_cmd_spi(mse, CMD_CTR);
323 ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
327 cmd_resp = be16_to_cpu(rx);
328 if ((cmd_resp & CMD_MASK) != CMD_RTS) {
329 net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
331 mse->stats.invalid_rts++;
335 net_dbg_ratelimited("%s: Unexpected response to first CMD\n",
339 rxlen = cmd_resp & LEN_MASK;
341 net_dbg_ratelimited("%s: No frame length defined\n", __func__);
342 mse->stats.invalid_len++;
346 rxalign = ALIGN(rxlen + DET_SOF_LEN + DET_DFT_LEN, 4);
347 skb = netdev_alloc_skb_ip_align(mse->ndev, rxalign);
351 /* 2 bytes Start of frame (before ethernet header)
352 * 2 bytes Data frame tail (after ethernet frame)
353 * They are copied, but ignored.
355 rxpkt = skb_put(skb, rxlen) - DET_SOF_LEN;
356 if (mse102x_rx_frame_spi(mse, rxpkt, rxlen)) {
357 mse->ndev->stats.rx_errors++;
362 if (netif_msg_pktdata(mse))
363 mse102x_dump_packet(__func__, skb->len, skb->data);
365 skb->protocol = eth_type_trans(skb, mse->ndev);
368 mse->ndev->stats.rx_packets++;
369 mse->ndev->stats.rx_bytes += rxlen;
372 static int mse102x_tx_pkt_spi(struct mse102x_net *mse, struct sk_buff *txb,
373 unsigned long work_timeout)
375 unsigned int pad = 0;
381 if (txb->len < ETH_ZLEN)
382 pad = ETH_ZLEN - txb->len;
385 mse102x_tx_cmd_spi(mse, CMD_RTS | (txb->len + pad));
386 ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
387 cmd_resp = be16_to_cpu(rx);
390 /* ready to send frame ? */
391 if (cmd_resp == CMD_CTR)
394 net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
396 mse->stats.invalid_ctr++;
399 /* It's not predictable how long / many retries it takes to
400 * send at least one packet, so TX timeouts are possible.
401 * That's the reason why the netdev watchdog is not used here.
403 if (time_after(jiffies, work_timeout))
407 /* throttle at first issue */
408 netif_stop_queue(mse->ndev);
410 usleep_range(50, 100);
417 ret = mse102x_tx_frame_spi(mse, txb, pad);
419 net_dbg_ratelimited("%s: Failed to send (%d), drop frame\n",
425 #define TX_QUEUE_MAX 10
427 static void mse102x_tx_work(struct work_struct *work)
429 /* Make sure timeout is sufficient to transfer TX_QUEUE_MAX frames */
430 unsigned long work_timeout = jiffies + msecs_to_jiffies(1000);
431 struct mse102x_net_spi *mses;
432 struct mse102x_net *mse;
436 mses = container_of(work, struct mse102x_net_spi, tx_work);
437 mse = &mses->mse102x;
439 while ((txb = skb_dequeue(&mse->txq))) {
440 unsigned int len = max_t(unsigned int, txb->len, ETH_ZLEN);
442 mutex_lock(&mses->lock);
443 ret = mse102x_tx_pkt_spi(mse, txb, work_timeout);
444 mutex_unlock(&mses->lock);
446 mse->ndev->stats.tx_dropped++;
448 mse->ndev->stats.tx_bytes += len;
449 mse->ndev->stats.tx_packets++;
455 if (ret == -ETIMEDOUT) {
456 if (netif_msg_timer(mse))
457 netdev_err_once(mse->ndev, "tx work timeout\n");
459 mse->stats.tx_timeout++;
462 netif_wake_queue(mse->ndev);
465 static netdev_tx_t mse102x_start_xmit_spi(struct sk_buff *skb,
466 struct net_device *ndev)
468 struct mse102x_net *mse = netdev_priv(ndev);
469 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
471 netif_dbg(mse, tx_queued, ndev,
472 "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
474 skb_queue_tail(&mse->txq, skb);
476 if (skb_queue_len(&mse->txq) >= TX_QUEUE_MAX)
477 netif_stop_queue(ndev);
479 schedule_work(&mses->tx_work);
484 static void mse102x_init_mac(struct mse102x_net *mse, struct device_node *np)
486 struct net_device *ndev = mse->ndev;
487 int ret = of_get_ethdev_address(np, ndev);
490 eth_hw_addr_random(ndev);
491 dev_warn(ndev->dev.parent, "Using random MAC address: %pM\n",
496 /* Assumption: this is called for every incoming packet */
497 static irqreturn_t mse102x_irq(int irq, void *_mse)
499 struct mse102x_net *mse = _mse;
500 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
502 mutex_lock(&mses->lock);
503 mse102x_rx_pkt_spi(mse);
504 mutex_unlock(&mses->lock);
509 static int mse102x_net_open(struct net_device *ndev)
511 struct mse102x_net *mse = netdev_priv(ndev);
514 ret = request_threaded_irq(ndev->irq, NULL, mse102x_irq, IRQF_ONESHOT,
517 netdev_err(ndev, "Failed to get irq: %d\n", ret);
521 netif_dbg(mse, ifup, ndev, "opening\n");
523 netif_start_queue(ndev);
525 netif_carrier_on(ndev);
527 netif_dbg(mse, ifup, ndev, "network device up\n");
532 static int mse102x_net_stop(struct net_device *ndev)
534 struct mse102x_net *mse = netdev_priv(ndev);
535 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
537 netif_info(mse, ifdown, ndev, "shutting down\n");
539 netif_carrier_off(mse->ndev);
541 /* stop any outstanding work */
542 flush_work(&mses->tx_work);
544 netif_stop_queue(ndev);
546 skb_queue_purge(&mse->txq);
548 free_irq(ndev->irq, mse);
553 static const struct net_device_ops mse102x_netdev_ops = {
554 .ndo_open = mse102x_net_open,
555 .ndo_stop = mse102x_net_stop,
556 .ndo_start_xmit = mse102x_start_xmit_spi,
557 .ndo_set_mac_address = eth_mac_addr,
558 .ndo_validate_addr = eth_validate_addr,
561 /* ethtool support */
563 static void mse102x_get_drvinfo(struct net_device *ndev,
564 struct ethtool_drvinfo *di)
566 strscpy(di->driver, DRV_NAME, sizeof(di->driver));
567 strscpy(di->bus_info, dev_name(ndev->dev.parent), sizeof(di->bus_info));
570 static u32 mse102x_get_msglevel(struct net_device *ndev)
572 struct mse102x_net *mse = netdev_priv(ndev);
574 return mse->msg_enable;
577 static void mse102x_set_msglevel(struct net_device *ndev, u32 to)
579 struct mse102x_net *mse = netdev_priv(ndev);
581 mse->msg_enable = to;
584 static void mse102x_get_ethtool_stats(struct net_device *ndev,
585 struct ethtool_stats *estats, u64 *data)
587 struct mse102x_net *mse = netdev_priv(ndev);
588 struct mse102x_stats *st = &mse->stats;
590 memcpy(data, st, ARRAY_SIZE(mse102x_gstrings_stats) * sizeof(u64));
593 static void mse102x_get_strings(struct net_device *ndev, u32 stringset, u8 *buf)
597 memcpy(buf, &mse102x_gstrings_stats,
598 sizeof(mse102x_gstrings_stats));
606 static int mse102x_get_sset_count(struct net_device *ndev, int sset)
610 return ARRAY_SIZE(mse102x_gstrings_stats);
616 static const struct ethtool_ops mse102x_ethtool_ops = {
617 .get_drvinfo = mse102x_get_drvinfo,
618 .get_link = ethtool_op_get_link,
619 .get_msglevel = mse102x_get_msglevel,
620 .set_msglevel = mse102x_set_msglevel,
621 .get_ethtool_stats = mse102x_get_ethtool_stats,
622 .get_strings = mse102x_get_strings,
623 .get_sset_count = mse102x_get_sset_count,
626 /* driver bus management functions */
628 static int mse102x_suspend(struct device *dev)
630 struct mse102x_net *mse = dev_get_drvdata(dev);
631 struct net_device *ndev = mse->ndev;
633 if (netif_running(ndev)) {
634 netif_device_detach(ndev);
635 mse102x_net_stop(ndev);
641 static int mse102x_resume(struct device *dev)
643 struct mse102x_net *mse = dev_get_drvdata(dev);
644 struct net_device *ndev = mse->ndev;
646 if (netif_running(ndev)) {
647 mse102x_net_open(ndev);
648 netif_device_attach(ndev);
654 static DEFINE_SIMPLE_DEV_PM_OPS(mse102x_pm_ops, mse102x_suspend, mse102x_resume);
656 static int mse102x_probe_spi(struct spi_device *spi)
658 struct device *dev = &spi->dev;
659 struct mse102x_net_spi *mses;
660 struct net_device *ndev;
661 struct mse102x_net *mse;
664 spi->bits_per_word = 8;
665 spi->mode |= SPI_MODE_3;
666 /* enforce minimum speed to ensure device functionality */
667 spi->controller->min_speed_hz = MIN_FREQ_HZ;
669 if (!spi->max_speed_hz)
670 spi->max_speed_hz = MAX_FREQ_HZ;
672 if (spi->max_speed_hz < MIN_FREQ_HZ ||
673 spi->max_speed_hz > MAX_FREQ_HZ) {
674 dev_err(&spi->dev, "SPI max frequency out of range (min: %u, max: %u)\n",
675 MIN_FREQ_HZ, MAX_FREQ_HZ);
679 ret = spi_setup(spi);
681 dev_err(&spi->dev, "Unable to setup SPI device: %d\n", ret);
685 ndev = devm_alloc_etherdev(dev, sizeof(struct mse102x_net_spi));
689 ndev->needed_tailroom += ALIGN(DET_DFT_LEN, 4);
690 ndev->needed_headroom += ALIGN(DET_SOF_LEN, 4);
691 ndev->priv_flags &= ~IFF_TX_SKB_SHARING;
692 ndev->tx_queue_len = 100;
694 mse = netdev_priv(ndev);
695 mses = to_mse102x_spi(mse);
698 mutex_init(&mses->lock);
699 INIT_WORK(&mses->tx_work, mse102x_tx_work);
701 /* initialise pre-made spi transfer messages */
702 spi_message_init(&mses->spi_msg);
703 spi_message_add_tail(&mses->spi_xfer, &mses->spi_msg);
705 ndev->irq = spi->irq;
708 /* set the default message enable */
709 mse->msg_enable = netif_msg_init(-1, MSG_DEFAULT);
711 skb_queue_head_init(&mse->txq);
713 SET_NETDEV_DEV(ndev, dev);
715 dev_set_drvdata(dev, mse);
717 netif_carrier_off(mse->ndev);
718 ndev->netdev_ops = &mse102x_netdev_ops;
719 ndev->ethtool_ops = &mse102x_ethtool_ops;
721 mse102x_init_mac(mse, dev->of_node);
723 ret = register_netdev(ndev);
725 dev_err(dev, "failed to register network device: %d\n", ret);
729 mse102x_init_device_debugfs(mses);
734 static void mse102x_remove_spi(struct spi_device *spi)
736 struct mse102x_net *mse = dev_get_drvdata(&spi->dev);
737 struct mse102x_net_spi *mses = to_mse102x_spi(mse);
739 mse102x_remove_device_debugfs(mses);
740 unregister_netdev(mse->ndev);
743 static const struct of_device_id mse102x_match_table[] = {
744 { .compatible = "vertexcom,mse1021" },
745 { .compatible = "vertexcom,mse1022" },
748 MODULE_DEVICE_TABLE(of, mse102x_match_table);
750 static const struct spi_device_id mse102x_ids[] = {
755 MODULE_DEVICE_TABLE(spi, mse102x_ids);
757 static struct spi_driver mse102x_driver = {
760 .of_match_table = mse102x_match_table,
761 .pm = pm_sleep_ptr(&mse102x_pm_ops),
763 .probe = mse102x_probe_spi,
764 .remove = mse102x_remove_spi,
765 .id_table = mse102x_ids,
767 module_spi_driver(mse102x_driver);
769 MODULE_DESCRIPTION("MSE102x Network driver");
771 MODULE_LICENSE("GPL");
772 MODULE_ALIAS("spi:" DRV_NAME);