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w5100: detect carrier state using link status bit and optional interrupt

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Detect the carrier state on the w5500 Ethernet controller using the
Link Status bit from the PHY Configuration register (PHYCFGR).

On w5100/w5200, which lack this register, get_link() is not implemented
and the carrier state is not reported (netif_carrier_(on|off) is not
called).

For the w5500, add an optional interrupt, wired to the LINKLED pin of
the device, to detect link status changes with a read of the PHYCFGR
register and update of the carrier state with netif_carrier_(on|off).
If this interrupt is not set in the DT binding, get_link() is not
implemented and the carrier state is not reported
(netif_carrier_(on|off) is not called).
The interrupt handler and the PHYCFGR register readings are
synchronized using a mutex.

A few changes are also brought for the bring-up/teardown
synchronization:

 - The net device is registered last in the probe() function so no
   operation can be performed before the probing is finished
 - The net device is unregistered first in remove()
 - dev_name is now used instead of netdev_name
 - w5100_stop() calls cancel_work_sync() and flush_work() to make sure
   there is no race condition or unfinished work
 - w5100_suspend() calls w5100_stop()
 - w5100_resume() calls w5100_open()
 - The main irq is not automatically enabled in w5100_probe() but in
   w5100_open() and disabled in w5100_stop()

Commit dacf281771 ("w5100: remove unused gpio link detection")
dropped the link_gpio/link_irq handling on the grounds that no
devicetree user passed a "link" gpio at the time and that it used the
old gpio interface.
This isn't a plain revert of that removal: link detection is now done
using a second interrupt rather than a gpio with a documented DT
binding.

Set the WIZNET entry as DRIVER and add drivers/net/ethernet/wiznet in
MAINTAINERS file.

Signed-off-by: Arthur Crepin Leblond <arthur@marmottus.net>
Fixes: dacf281771 ("w5100: remove unused gpio link detection")
Link: https://patch.msgid.link/20260924-wiznet-link-gpio-v11-3-42a332517b30@marmottus.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Arthur Crepin Leblond 2026-09-24 11:48:13 +02:00 committed by Jakub Kicinski
parent 50c4bbaa0d
commit 323767fa31
2 changed files with 206 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
MAINTAINERS
View File

@ -29455,11 +29455,12 @@ M: Miloslav Trmac <mitr@volny.cz>
S: Maintained
F: drivers/input/misc/wistron_btns.c
WIZNET W5100 ETHERNET BINDINGS
WIZNET W5100 ETHERNET DRIVER
M: Arthur Crepin Leblond <arthur@marmottus.net>
L: netdev@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/net/wiznet,w5100.yaml
F: drivers/net/ethernet/wiznet/
WMI BINARY MOF DRIVER
M: Armin Wolf <W_Armin@gmx.de>

234
drivers/net/ethernet/wiznet/w5100.c
View File

@ -18,9 +18,11 @@
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/property.h>
#include <linux/irq.h>
#include "w5100.h"
@ -124,6 +126,8 @@ MODULE_LICENSE("GPL");
*/
#define W5500_SIMR 0x0018 /* Socket Interrupt Mask Register */
#define W5500_RTR 0x0019 /* Retry Time-value Register */
#define W5500_PHYCFGR 0x002e /* PHY Configuration Register */
#define PHYCFGR_LNK 0x01 /* Link status */
#define W5500_S0_REGS 0x10000
@ -154,6 +158,9 @@ struct w5100_priv {
u16 s0_rx_buf_size;
int irq;
int link_irq;
/* Protects link state and carrier updates */
struct mutex link_lock;
struct napi_struct napi;
struct net_device *ndev;
@ -345,6 +352,82 @@ static void w5500_memory_configure(struct w5100_priv *priv)
}
}
static int w5500_get_phycfgr_lnk(struct net_device *ndev)
{
struct w5100_priv *priv = netdev_priv(ndev);
int retries = 3;
int ret;
do {
ret = w5100_read(priv, W5500_PHYCFGR);
if (ret < 0)
netif_err(priv, link, ndev,
"failed to read link status: %d\n", ret);
} while (ret < 0 && --retries);
if (ret < 0)
return ret;
return ret & PHYCFGR_LNK;
}
static void w5500_report_carrier_state(struct net_device *ndev)
{
struct w5100_priv *priv = netdev_priv(ndev);
int state;
mutex_lock(&priv->link_lock);
state = w5500_get_phycfgr_lnk(ndev);
if (state > 0) {
netif_info(priv, link, ndev, "link is up\n");
netif_carrier_on(ndev);
} else if (state == 0) {
netif_info(priv, link, ndev, "link is down\n");
netif_carrier_off(ndev);
}
mutex_unlock(&priv->link_lock);
}
static irqreturn_t w5500_detect_link_interrupt(int irq, void *ndev_instance)
{
struct net_device *ndev = ndev_instance;
if (netif_running(ndev))
w5500_report_carrier_state(ndev);
return IRQ_HANDLED;
}
static u32 w5500_get_link(struct net_device *ndev)
{
struct w5100_priv *priv = netdev_priv(ndev);
int state;
bool link;
mutex_lock(&priv->link_lock);
if (!netif_device_present(ndev)) {
link = netif_carrier_ok(ndev);
goto out;
}
state = w5500_get_phycfgr_lnk(ndev);
if (state < 0) {
link = netif_carrier_ok(ndev);
goto out;
}
link = state > 0;
out:
mutex_unlock(&priv->link_lock);
return link;
}
static int w5100_hw_reset(struct w5100_priv *priv)
{
u32 rtr;
@ -448,12 +531,28 @@ static void w5100_restart(struct net_device *ndev)
{
struct w5100_priv *priv = netdev_priv(ndev);
if (!netif_running(ndev) || !netif_device_present(ndev))
return;
disable_irq(priv->irq);
if (priv->link_irq > 0)
disable_irq(priv->link_irq);
netif_stop_queue(ndev);
w5100_hw_close(priv);
flush_work(&priv->rx_work);
flush_work(&priv->tx_work);
w5100_hw_reset(priv);
enable_irq(priv->irq);
w5100_hw_start(priv);
ndev->stats.tx_errors++;
netif_trans_update(ndev);
netif_wake_queue(ndev);
if (priv->link_irq > 0) {
enable_irq(priv->link_irq);
w5500_report_carrier_state(ndev);
}
}
static void w5100_restart_work(struct work_struct *work)
@ -468,10 +567,7 @@ static void w5100_tx_timeout(struct net_device *ndev, unsigned int txqueue)
{
struct w5100_priv *priv = netdev_priv(ndev);
if (priv->ops->may_sleep)
schedule_work(&priv->restart_work);
else
w5100_restart(ndev);
schedule_work(&priv->restart_work);
}
static void w5100_tx_skb(struct net_device *ndev, struct sk_buff *skb)
@ -564,7 +660,8 @@ static void w5100_rx_work(struct work_struct *work)
while ((skb = w5100_rx_skb(priv->ndev)))
netif_rx(skb);
w5100_enable_intr(priv);
if (netif_running(priv->ndev))
w5100_enable_intr(priv);
}
static int w5100_napi_poll(struct napi_struct *napi, int budget)
@ -656,9 +753,17 @@ static int w5100_open(struct net_device *ndev)
struct w5100_priv *priv = netdev_priv(ndev);
netif_info(priv, ifup, ndev, "enabling\n");
w5100_hw_reset(priv);
enable_irq(priv->irq);
w5100_hw_start(priv);
napi_enable(&priv->napi);
netif_start_queue(ndev);
if (priv->link_irq > 0) {
enable_irq(priv->link_irq);
w5500_report_carrier_state(ndev);
}
return 0;
}
@ -667,13 +772,40 @@ static int w5100_stop(struct net_device *ndev)
struct w5100_priv *priv = netdev_priv(ndev);
netif_info(priv, ifdown, ndev, "shutting down\n");
w5100_hw_close(priv);
netif_carrier_off(ndev);
disable_irq(priv->irq);
if (priv->link_irq > 0)
disable_irq(priv->link_irq);
netif_stop_queue(ndev);
napi_disable(&priv->napi);
cancel_work_sync(&priv->restart_work);
cancel_work_sync(&priv->setrx_work);
w5100_hw_close(priv);
flush_work(&priv->rx_work);
flush_work(&priv->tx_work);
if (priv->link_irq > 0) {
mutex_lock(&priv->link_lock);
netif_carrier_off(ndev);
mutex_unlock(&priv->link_lock);
}
return 0;
}
static const struct ethtool_ops w5500_ethtool_ops = {
.get_drvinfo = w5100_get_drvinfo,
.get_msglevel = w5100_get_msglevel,
.set_msglevel = w5100_set_msglevel,
.get_link = w5500_get_link,
.get_regs_len = w5100_get_regs_len,
.get_regs = w5100_get_regs,
};
static const struct ethtool_ops w5100_ethtool_ops = {
.get_drvinfo = w5100_get_drvinfo,
.get_msglevel = w5100_get_msglevel,
@ -721,6 +853,8 @@ int w5100_probe(struct device *dev, const struct w5100_ops *ops,
dev_set_drvdata(dev, ndev);
priv = netdev_priv(ndev);
mutex_init(&priv->link_lock);
switch (ops->chip_id) {
case W5100:
priv->s0_regs = W5100_S0_REGS;
@ -745,15 +879,27 @@ int w5100_probe(struct device *dev, const struct w5100_ops *ops,
break;
default:
err = -EINVAL;
goto err_register;
goto err_mutex;
}
priv->ndev = ndev;
priv->ops = ops;
priv->irq = irq;
priv->link_irq = -EINVAL;
if (ops->chip_id == W5500) {
priv->link_irq = fwnode_irq_get(dev_fwnode(dev), 1);
if (priv->link_irq == -EPROBE_DEFER) {
err = dev_err_probe(dev, priv->link_irq,
"failed to get link irq\n");
goto err_mutex;
}
}
ndev->netdev_ops = &w5100_netdev_ops;
ndev->ethtool_ops = &w5100_ethtool_ops;
ndev->ethtool_ops = priv->link_irq > 0 ? &w5500_ethtool_ops :
&w5100_ethtool_ops;
netif_napi_add_weight(ndev, &priv->napi, w5100_napi_poll, 16);
/* This chip doesn't support VLAN packets with normal MTU,
@ -761,15 +907,11 @@ int w5100_probe(struct device *dev, const struct w5100_ops *ops,
*/
ndev->features |= NETIF_F_VLAN_CHALLENGED;
err = register_netdev(ndev);
if (err < 0)
goto err_register;
priv->xfer_wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_PERCPU, 0,
netdev_name(ndev));
dev_name(dev));
if (!priv->xfer_wq) {
err = -ENOMEM;
goto err_wq;
goto err_mutex;
}
INIT_WORK(&priv->rx_work, w5100_rx_work);
@ -794,22 +936,45 @@ int w5100_probe(struct device *dev, const struct w5100_ops *ops,
if (ops->may_sleep) {
err = request_threaded_irq(priv->irq, NULL, w5100_interrupt,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
netdev_name(ndev), ndev);
IRQF_TRIGGER_LOW | IRQF_ONESHOT |
IRQF_NO_AUTOEN,
dev_name(dev), ndev);
} else {
err = request_irq(priv->irq, w5100_interrupt,
IRQF_TRIGGER_LOW, netdev_name(ndev), ndev);
IRQF_TRIGGER_LOW | IRQF_NO_AUTOEN,
dev_name(dev), ndev);
}
if (err)
goto err_hw;
if (priv->link_irq > 0) {
err = request_threaded_irq(priv->link_irq, NULL,
w5500_detect_link_interrupt,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING |
IRQF_ONESHOT | IRQF_NO_AUTOEN,
"w5100-link", ndev);
if (err < 0)
goto err_irq;
netif_carrier_off(ndev);
}
err = register_netdev(ndev);
if (err < 0)
goto err_link_irq;
return 0;
err_link_irq:
if (priv->link_irq > 0)
free_irq(priv->link_irq, ndev);
err_irq:
free_irq(priv->irq, ndev);
err_hw:
destroy_workqueue(priv->xfer_wq);
err_wq:
unregister_netdev(ndev);
err_register:
err_mutex:
mutex_destroy(&priv->link_lock);
free_netdev(ndev);
return err;
}
@ -820,14 +985,21 @@ void w5100_remove(struct device *dev)
struct net_device *ndev = dev_get_drvdata(dev);
struct w5100_priv *priv = netdev_priv(ndev);
w5100_hw_reset(priv);
unregister_netdev(ndev);
if (priv->link_irq > 0)
free_irq(priv->link_irq, ndev);
free_irq(priv->irq, ndev);
flush_work(&priv->setrx_work);
flush_work(&priv->restart_work);
destroy_workqueue(priv->xfer_wq);
cancel_work_sync(&priv->setrx_work);
cancel_work_sync(&priv->restart_work);
flush_work(&priv->rx_work);
flush_work(&priv->tx_work);
unregister_netdev(ndev);
w5100_hw_reset(priv);
destroy_workqueue(priv->xfer_wq);
mutex_destroy(&priv->link_lock);
free_netdev(ndev);
}
EXPORT_SYMBOL_GPL(w5100_remove);
@ -839,10 +1011,11 @@ static int w5100_suspend(struct device *dev)
struct w5100_priv *priv = netdev_priv(ndev);
if (netif_running(ndev)) {
netif_carrier_off(ndev);
mutex_lock(&priv->link_lock);
netif_device_detach(ndev);
mutex_unlock(&priv->link_lock);
w5100_hw_close(priv);
w5100_stop(ndev);
}
return 0;
}
@ -853,10 +1026,11 @@ static int w5100_resume(struct device *dev)
struct w5100_priv *priv = netdev_priv(ndev);
if (netif_running(ndev)) {
w5100_hw_reset(priv);
w5100_hw_start(priv);
w5100_open(ndev);
mutex_lock(&priv->link_lock);
netif_device_attach(ndev);
mutex_unlock(&priv->link_lock);
}
return 0;
}