blob: edd8b59680e5382089c78c071a7d01613b8ab682 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2021 in-tech smart charging GmbH
*
* driver is based on micrel/ks8851_spi.c
*/
#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/debugfs.h>
#include <linux/seq_file.h>
#include <linux/spi/spi.h>
#include <linux/of_net.h>
#define MSG_DEFAULT (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK | \
NETIF_MSG_TIMER)
#define DRV_NAME "mse102x"
#define DET_CMD 0x0001
#define DET_SOF 0x0002
#define DET_DFT 0x55AA
#define CMD_SHIFT 12
#define CMD_RTS (0x1 << CMD_SHIFT)
#define CMD_CTR (0x2 << CMD_SHIFT)
#define CMD_MASK GENMASK(15, CMD_SHIFT)
#define LEN_MASK GENMASK(CMD_SHIFT - 1, 0)
#define DET_CMD_LEN 4
#define DET_SOF_LEN 2
#define DET_DFT_LEN 2
#define MIN_FREQ_HZ 6000000
#define MAX_FREQ_HZ 7142857
struct mse102x_stats {
u64 xfer_err;
u64 invalid_cmd;
u64 invalid_ctr;
u64 invalid_dft;
u64 invalid_len;
u64 invalid_rts;
u64 invalid_sof;
u64 tx_timeout;
};
static const char mse102x_gstrings_stats[][ETH_GSTRING_LEN] = {
"SPI transfer errors",
"Invalid command",
"Invalid CTR",
"Invalid DFT",
"Invalid frame length",
"Invalid RTS",
"Invalid SOF",
"TX timeout",
};
struct mse102x_net {
struct net_device *ndev;
u8 rxd[8];
u8 txd[8];
u32 msg_enable ____cacheline_aligned;
struct sk_buff_head txq;
struct mse102x_stats stats;
};
struct mse102x_net_spi {
struct mse102x_net mse102x;
struct mutex lock; /* Protect SPI frame transfer */
struct work_struct tx_work;
struct spi_device *spidev;
struct spi_message spi_msg;
struct spi_transfer spi_xfer;
#ifdef CONFIG_DEBUG_FS
struct dentry *device_root;
#endif
};
#define to_mse102x_spi(mse) container_of((mse), struct mse102x_net_spi, mse102x)
#ifdef CONFIG_DEBUG_FS
static int mse102x_info_show(struct seq_file *s, void *what)
{
struct mse102x_net_spi *mses = s->private;
seq_printf(s, "TX ring size : %u\n",
skb_queue_len(&mses->mse102x.txq));
seq_printf(s, "IRQ : %d\n",
mses->spidev->irq);
seq_printf(s, "SPI effective speed : %lu\n",
(unsigned long)mses->spi_xfer.effective_speed_hz);
seq_printf(s, "SPI mode : %x\n",
mses->spidev->mode);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(mse102x_info);
static void mse102x_init_device_debugfs(struct mse102x_net_spi *mses)
{
mses->device_root = debugfs_create_dir(dev_name(&mses->mse102x.ndev->dev),
NULL);
debugfs_create_file("info", S_IFREG | 0444, mses->device_root, mses,
&mse102x_info_fops);
}
static void mse102x_remove_device_debugfs(struct mse102x_net_spi *mses)
{
debugfs_remove_recursive(mses->device_root);
}
#else /* CONFIG_DEBUG_FS */
static void mse102x_init_device_debugfs(struct mse102x_net_spi *mses)
{
}
static void mse102x_remove_device_debugfs(struct mse102x_net_spi *mses)
{
}
#endif
/* 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.
*/
static void mse102x_tx_cmd_spi(struct mse102x_net *mse, u16 cmd)
{
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
struct spi_transfer *xfer = &mses->spi_xfer;
struct spi_message *msg = &mses->spi_msg;
__be16 txb[2];
int ret;
txb[0] = cpu_to_be16(DET_CMD);
txb[1] = cpu_to_be16(cmd);
xfer->tx_buf = txb;
xfer->rx_buf = NULL;
xfer->len = DET_CMD_LEN;
ret = spi_sync(mses->spidev, msg);
if (ret < 0) {
netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
__func__, ret);
mse->stats.xfer_err++;
}
}
static int mse102x_rx_cmd_spi(struct mse102x_net *mse, u8 *rxb)
{
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
struct spi_transfer *xfer = &mses->spi_xfer;
struct spi_message *msg = &mses->spi_msg;
__be16 *txb = (__be16 *)mse->txd;
__be16 *cmd = (__be16 *)mse->rxd;
u8 *trx = mse->rxd;
int ret;
txb[0] = 0;
txb[1] = 0;
xfer->tx_buf = txb;
xfer->rx_buf = trx;
xfer->len = DET_CMD_LEN;
ret = spi_sync(mses->spidev, msg);
if (ret < 0) {
netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
__func__, ret);
mse->stats.xfer_err++;
} else if (*cmd != cpu_to_be16(DET_CMD)) {
net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
__func__, *cmd);
mse->stats.invalid_cmd++;
ret = -EIO;
} else {
memcpy(rxb, trx + 2, 2);
}
return ret;
}
static inline void mse102x_push_header(struct sk_buff *skb)
{
__be16 *header = skb_push(skb, DET_SOF_LEN);
*header = cpu_to_be16(DET_SOF);
}
static inline void mse102x_put_footer(struct sk_buff *skb)
{
__be16 *footer = skb_put(skb, DET_DFT_LEN);
*footer = cpu_to_be16(DET_DFT);
}
static int mse102x_tx_frame_spi(struct mse102x_net *mse, struct sk_buff *txp,
unsigned int pad)
{
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
struct spi_transfer *xfer = &mses->spi_xfer;
struct spi_message *msg = &mses->spi_msg;
struct sk_buff *tskb;
int ret;
netif_dbg(mse, tx_queued, mse->ndev, "%s: skb %p, %d@%p\n",
__func__, txp, txp->len, txp->data);
if ((skb_headroom(txp) < DET_SOF_LEN) ||
(skb_tailroom(txp) < DET_DFT_LEN + pad)) {
tskb = skb_copy_expand(txp, DET_SOF_LEN, DET_DFT_LEN + pad,
GFP_KERNEL);
if (!tskb)
return -ENOMEM;
dev_kfree_skb(txp);
txp = tskb;
}
mse102x_push_header(txp);
if (pad)
skb_put_zero(txp, pad);
mse102x_put_footer(txp);
xfer->tx_buf = txp->data;
xfer->rx_buf = NULL;
xfer->len = txp->len;
ret = spi_sync(mses->spidev, msg);
if (ret < 0) {
netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
__func__, ret);
mse->stats.xfer_err++;
}
return ret;
}
static int mse102x_rx_frame_spi(struct mse102x_net *mse, u8 *buff,
unsigned int frame_len)
{
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
struct spi_transfer *xfer = &mses->spi_xfer;
struct spi_message *msg = &mses->spi_msg;
__be16 *sof = (__be16 *)buff;
__be16 *dft = (__be16 *)(buff + DET_SOF_LEN + frame_len);
int ret;
xfer->rx_buf = buff;
xfer->tx_buf = NULL;
xfer->len = DET_SOF_LEN + frame_len + DET_DFT_LEN;
ret = spi_sync(mses->spidev, msg);
if (ret < 0) {
netdev_err(mse->ndev, "%s: spi_sync() failed: %d\n",
__func__, ret);
mse->stats.xfer_err++;
} else if (*sof != cpu_to_be16(DET_SOF)) {
netdev_dbg(mse->ndev, "%s: SPI start of frame is invalid (0x%04x)\n",
__func__, *sof);
mse->stats.invalid_sof++;
ret = -EIO;
} else if (*dft != cpu_to_be16(DET_DFT)) {
netdev_dbg(mse->ndev, "%s: SPI frame tail is invalid (0x%04x)\n",
__func__, *dft);
mse->stats.invalid_dft++;
ret = -EIO;
}
return ret;
}
static void mse102x_dump_packet(const char *msg, int len, const char *data)
{
printk(KERN_DEBUG ": %s - packet len:%d\n", msg, len);
print_hex_dump(KERN_DEBUG, "pk data: ", DUMP_PREFIX_OFFSET, 16, 1,
data, len, true);
}
static void mse102x_rx_pkt_spi(struct mse102x_net *mse)
{
struct sk_buff *skb;
unsigned int rxalign;
unsigned int rxlen;
__be16 rx = 0;
u16 cmd_resp;
u8 *rxpkt;
int ret;
mse102x_tx_cmd_spi(mse, CMD_CTR);
ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
cmd_resp = be16_to_cpu(rx);
if (ret || ((cmd_resp & CMD_MASK) != CMD_RTS)) {
usleep_range(50, 100);
mse102x_tx_cmd_spi(mse, CMD_CTR);
ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
if (ret)
return;
cmd_resp = be16_to_cpu(rx);
if ((cmd_resp & CMD_MASK) != CMD_RTS) {
net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
__func__, cmd_resp);
mse->stats.invalid_rts++;
return;
}
net_dbg_ratelimited("%s: Unexpected response to first CMD\n",
__func__);
}
rxlen = cmd_resp & LEN_MASK;
if (!rxlen) {
net_dbg_ratelimited("%s: No frame length defined\n", __func__);
mse->stats.invalid_len++;
return;
}
rxalign = ALIGN(rxlen + DET_SOF_LEN + DET_DFT_LEN, 4);
skb = netdev_alloc_skb_ip_align(mse->ndev, rxalign);
if (!skb)
return;
/* 2 bytes Start of frame (before ethernet header)
* 2 bytes Data frame tail (after ethernet frame)
* They are copied, but ignored.
*/
rxpkt = skb_put(skb, rxlen) - DET_SOF_LEN;
if (mse102x_rx_frame_spi(mse, rxpkt, rxlen)) {
mse->ndev->stats.rx_errors++;
dev_kfree_skb(skb);
return;
}
if (netif_msg_pktdata(mse))
mse102x_dump_packet(__func__, skb->len, skb->data);
skb->protocol = eth_type_trans(skb, mse->ndev);
netif_rx(skb);
mse->ndev->stats.rx_packets++;
mse->ndev->stats.rx_bytes += rxlen;
}
static int mse102x_tx_pkt_spi(struct mse102x_net *mse, struct sk_buff *txb,
unsigned long work_timeout)
{
unsigned int pad = 0;
__be16 rx = 0;
u16 cmd_resp;
int ret;
bool first = true;
if (txb->len < 60)
pad = 60 - txb->len;
while (1) {
mse102x_tx_cmd_spi(mse, CMD_RTS | (txb->len + pad));
ret = mse102x_rx_cmd_spi(mse, (u8 *)&rx);
cmd_resp = be16_to_cpu(rx);
if (!ret) {
/* ready to send frame ? */
if (cmd_resp == CMD_CTR)
break;
net_dbg_ratelimited("%s: Unexpected response (0x%04x)\n",
__func__, cmd_resp);
mse->stats.invalid_ctr++;
}
/* It's not predictable how long / many retries it takes to
* send at least one packet, so TX timeouts are possible.
* That's the reason why the netdev watchdog is not used here.
*/
if (time_after(jiffies, work_timeout))
return -ETIMEDOUT;
if (first) {
/* throttle at first issue */
netif_stop_queue(mse->ndev);
/* fast retry */
usleep_range(50, 100);
first = false;
} else {
msleep(20);
}
}
ret = mse102x_tx_frame_spi(mse, txb, pad);
if (ret)
net_dbg_ratelimited("%s: Failed to send (%d), drop frame\n",
__func__, ret);
return ret;
}
#define TX_QUEUE_MAX 10
static void mse102x_tx_work(struct work_struct *work)
{
/* Make sure timeout is sufficient to transfer TX_QUEUE_MAX frames */
unsigned long work_timeout = jiffies + msecs_to_jiffies(1000);
struct mse102x_net_spi *mses;
struct mse102x_net *mse;
struct sk_buff *txb;
int ret = 0;
mses = container_of(work, struct mse102x_net_spi, tx_work);
mse = &mses->mse102x;
while ((txb = skb_dequeue(&mse->txq))) {
mutex_lock(&mses->lock);
ret = mse102x_tx_pkt_spi(mse, txb, work_timeout);
mutex_unlock(&mses->lock);
if (ret) {
mse->ndev->stats.tx_dropped++;
} else {
mse->ndev->stats.tx_bytes += txb->len;
mse->ndev->stats.tx_packets++;
}
dev_kfree_skb(txb);
}
if (ret == -ETIMEDOUT) {
if (netif_msg_timer(mse))
netdev_err(mse->ndev, "tx work timeout\n");
mse->stats.tx_timeout++;
}
netif_wake_queue(mse->ndev);
}
static netdev_tx_t mse102x_start_xmit_spi(struct sk_buff *skb,
struct net_device *ndev)
{
struct mse102x_net *mse = netdev_priv(ndev);
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
netif_dbg(mse, tx_queued, ndev,
"%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);
skb_queue_tail(&mse->txq, skb);
if (skb_queue_len(&mse->txq) >= TX_QUEUE_MAX)
netif_stop_queue(ndev);
schedule_work(&mses->tx_work);
return NETDEV_TX_OK;
}
static void mse102x_init_mac(struct mse102x_net *mse, struct device_node *np)
{
struct net_device *ndev = mse->ndev;
int ret = of_get_ethdev_address(np, ndev);
if (ret) {
eth_hw_addr_random(ndev);
netdev_err(ndev, "Using random MAC address: %pM\n",
ndev->dev_addr);
}
}
/* Assumption: this is called for every incoming packet */
static irqreturn_t mse102x_irq(int irq, void *_mse)
{
struct mse102x_net *mse = _mse;
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
mutex_lock(&mses->lock);
mse102x_rx_pkt_spi(mse);
mutex_unlock(&mses->lock);
return IRQ_HANDLED;
}
static int mse102x_net_open(struct net_device *ndev)
{
struct mse102x_net *mse = netdev_priv(ndev);
int ret;
ret = request_threaded_irq(ndev->irq, NULL, mse102x_irq, IRQF_ONESHOT,
ndev->name, mse);
if (ret < 0) {
netdev_err(ndev, "Failed to get irq: %d\n", ret);
return ret;
}
netif_dbg(mse, ifup, ndev, "opening\n");
netif_start_queue(ndev);
netif_carrier_on(ndev);
netif_dbg(mse, ifup, ndev, "network device up\n");
return 0;
}
static int mse102x_net_stop(struct net_device *ndev)
{
struct mse102x_net *mse = netdev_priv(ndev);
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
netif_info(mse, ifdown, ndev, "shutting down\n");
netif_carrier_off(mse->ndev);
/* stop any outstanding work */
flush_work(&mses->tx_work);
netif_stop_queue(ndev);
skb_queue_purge(&mse->txq);
free_irq(ndev->irq, mse);
return 0;
}
static const struct net_device_ops mse102x_netdev_ops = {
.ndo_open = mse102x_net_open,
.ndo_stop = mse102x_net_stop,
.ndo_start_xmit = mse102x_start_xmit_spi,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
};
/* ethtool support */
static void mse102x_get_drvinfo(struct net_device *ndev,
struct ethtool_drvinfo *di)
{
strscpy(di->driver, DRV_NAME, sizeof(di->driver));
strscpy(di->bus_info, dev_name(ndev->dev.parent), sizeof(di->bus_info));
}
static u32 mse102x_get_msglevel(struct net_device *ndev)
{
struct mse102x_net *mse = netdev_priv(ndev);
return mse->msg_enable;
}
static void mse102x_set_msglevel(struct net_device *ndev, u32 to)
{
struct mse102x_net *mse = netdev_priv(ndev);
mse->msg_enable = to;
}
static void mse102x_get_ethtool_stats(struct net_device *ndev,
struct ethtool_stats *estats, u64 *data)
{
struct mse102x_net *mse = netdev_priv(ndev);
struct mse102x_stats *st = &mse->stats;
memcpy(data, st, ARRAY_SIZE(mse102x_gstrings_stats) * sizeof(u64));
}
static void mse102x_get_strings(struct net_device *ndev, u32 stringset, u8 *buf)
{
switch (stringset) {
case ETH_SS_STATS:
memcpy(buf, &mse102x_gstrings_stats,
sizeof(mse102x_gstrings_stats));
break;
default:
WARN_ON(1);
break;
}
}
static int mse102x_get_sset_count(struct net_device *ndev, int sset)
{
switch (sset) {
case ETH_SS_STATS:
return ARRAY_SIZE(mse102x_gstrings_stats);
default:
return -EINVAL;
}
}
static const struct ethtool_ops mse102x_ethtool_ops = {
.get_drvinfo = mse102x_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_msglevel = mse102x_get_msglevel,
.set_msglevel = mse102x_set_msglevel,
.get_ethtool_stats = mse102x_get_ethtool_stats,
.get_strings = mse102x_get_strings,
.get_sset_count = mse102x_get_sset_count,
};
/* driver bus management functions */
#ifdef CONFIG_PM_SLEEP
static int mse102x_suspend(struct device *dev)
{
struct mse102x_net *mse = dev_get_drvdata(dev);
struct net_device *ndev = mse->ndev;
if (netif_running(ndev)) {
netif_device_detach(ndev);
mse102x_net_stop(ndev);
}
return 0;
}
static int mse102x_resume(struct device *dev)
{
struct mse102x_net *mse = dev_get_drvdata(dev);
struct net_device *ndev = mse->ndev;
if (netif_running(ndev)) {
mse102x_net_open(ndev);
netif_device_attach(ndev);
}
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(mse102x_pm_ops, mse102x_suspend, mse102x_resume);
static int mse102x_probe_spi(struct spi_device *spi)
{
struct device *dev = &spi->dev;
struct mse102x_net_spi *mses;
struct net_device *ndev;
struct mse102x_net *mse;
int ret;
spi->bits_per_word = 8;
spi->mode |= SPI_MODE_3;
/* enforce minimum speed to ensure device functionality */
spi->controller->min_speed_hz = MIN_FREQ_HZ;
if (!spi->max_speed_hz)
spi->max_speed_hz = MAX_FREQ_HZ;
if (spi->max_speed_hz < MIN_FREQ_HZ ||
spi->max_speed_hz > MAX_FREQ_HZ) {
dev_err(&spi->dev, "SPI max frequency out of range (min: %u, max: %u)\n",
MIN_FREQ_HZ, MAX_FREQ_HZ);
return -EINVAL;
}
ret = spi_setup(spi);
if (ret < 0) {
dev_err(&spi->dev, "Unable to setup SPI device: %d\n", ret);
return ret;
}
ndev = devm_alloc_etherdev(dev, sizeof(struct mse102x_net_spi));
if (!ndev)
return -ENOMEM;
ndev->needed_tailroom += ALIGN(DET_DFT_LEN, 4);
ndev->needed_headroom += ALIGN(DET_SOF_LEN, 4);
ndev->priv_flags &= ~IFF_TX_SKB_SHARING;
ndev->tx_queue_len = 100;
mse = netdev_priv(ndev);
mses = to_mse102x_spi(mse);
mses->spidev = spi;
mutex_init(&mses->lock);
INIT_WORK(&mses->tx_work, mse102x_tx_work);
/* initialise pre-made spi transfer messages */
spi_message_init(&mses->spi_msg);
spi_message_add_tail(&mses->spi_xfer, &mses->spi_msg);
ndev->irq = spi->irq;
mse->ndev = ndev;
/* set the default message enable */
mse->msg_enable = netif_msg_init(-1, MSG_DEFAULT);
skb_queue_head_init(&mse->txq);
SET_NETDEV_DEV(ndev, dev);
dev_set_drvdata(dev, mse);
netif_carrier_off(mse->ndev);
ndev->netdev_ops = &mse102x_netdev_ops;
ndev->ethtool_ops = &mse102x_ethtool_ops;
mse102x_init_mac(mse, dev->of_node);
ret = register_netdev(ndev);
if (ret) {
dev_err(dev, "failed to register network device: %d\n", ret);
return ret;
}
mse102x_init_device_debugfs(mses);
return 0;
}
static void mse102x_remove_spi(struct spi_device *spi)
{
struct mse102x_net *mse = dev_get_drvdata(&spi->dev);
struct mse102x_net_spi *mses = to_mse102x_spi(mse);
if (netif_msg_drv(mse))
dev_info(&spi->dev, "remove\n");
mse102x_remove_device_debugfs(mses);
unregister_netdev(mse->ndev);
}
static const struct of_device_id mse102x_match_table[] = {
{ .compatible = "vertexcom,mse1021" },
{ .compatible = "vertexcom,mse1022" },
{ }
};
MODULE_DEVICE_TABLE(of, mse102x_match_table);
static const struct spi_device_id mse102x_ids[] = {
{ "mse1021" },
{ "mse1022" },
{ }
};
MODULE_DEVICE_TABLE(spi, mse102x_ids);
static struct spi_driver mse102x_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = mse102x_match_table,
.pm = &mse102x_pm_ops,
},
.probe = mse102x_probe_spi,
.remove = mse102x_remove_spi,
.id_table = mse102x_ids,
};
module_spi_driver(mse102x_driver);
MODULE_DESCRIPTION("MSE102x Network driver");
MODULE_AUTHOR("Stefan Wahren <stefan.wahren@chargebyte.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:" DRV_NAME);