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linux/drivers/net/dsa/xrs700x/xrs700x_mdio.c
Vladimir Oltean a68e9da485 net: dsa: xrs700x: be compatible with masters which unregister on shutdown
Since commit 2f1e8ea726 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.

Since the Arrow SpeedChips XRS700x driver was introduced after the bad
commit, it has never worked with DSA masters which decide to unregister
their net_device on shutdown, effectively hanging the reboot process.
To fix that, we need to call dsa_switch_shutdown.

These devices can be connected by I2C or by MDIO, and if I search for
I2C or MDIO bus drivers that implement their ->shutdown by redirecting
it to ->remove I don't see any, however this does not mean it would not
be possible. To be compatible with that pattern, it is necessary to
implement an "if this then not that" scheme, to avoid ->remove and
->shutdown from being called both for the same struct device.

Fixes: ee00b24f32 ("net: dsa: add Arrow SpeedChips XRS700x driver")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/
Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-19 12:08:37 +01:00

182 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 NovaTech LLC
* George McCollister <george.mccollister@gmail.com>
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/mdio.h>
#include <linux/module.h>
#include <linux/phy.h>
#include <linux/if_vlan.h>
#include <linux/of.h>
#include "xrs700x.h"
#include "xrs700x_reg.h"
#define XRS_MDIO_IBA0 0x10
#define XRS_MDIO_IBA1 0x11
#define XRS_MDIO_IBD 0x14
#define XRS_IB_READ 0x0
#define XRS_IB_WRITE 0x1
static int xrs700x_mdio_reg_read(void *context, unsigned int reg,
unsigned int *val)
{
struct mdio_device *mdiodev = context;
struct device *dev = &mdiodev->dev;
u16 uval;
int ret;
uval = (u16)FIELD_GET(GENMASK(31, 16), reg);
ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA1, uval);
if (ret < 0) {
dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
return ret;
}
uval = (u16)((reg & GENMASK(15, 1)) | XRS_IB_READ);
ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA0, uval);
if (ret < 0) {
dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
return ret;
}
ret = mdiobus_read(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBD);
if (ret < 0) {
dev_err(dev, "xrs mdiobus_read returned %d\n", ret);
return ret;
}
*val = (unsigned int)ret;
return 0;
}
static int xrs700x_mdio_reg_write(void *context, unsigned int reg,
unsigned int val)
{
struct mdio_device *mdiodev = context;
struct device *dev = &mdiodev->dev;
u16 uval;
int ret;
ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBD, (u16)val);
if (ret < 0) {
dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
return ret;
}
uval = (u16)FIELD_GET(GENMASK(31, 16), reg);
ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA1, uval);
if (ret < 0) {
dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
return ret;
}
uval = (u16)((reg & GENMASK(15, 1)) | XRS_IB_WRITE);
ret = mdiobus_write(mdiodev->bus, mdiodev->addr, XRS_MDIO_IBA0, uval);
if (ret < 0) {
dev_err(dev, "xrs mdiobus_write returned %d\n", ret);
return ret;
}
return 0;
}
static const struct regmap_config xrs700x_mdio_regmap_config = {
.val_bits = 16,
.reg_stride = 2,
.reg_bits = 32,
.pad_bits = 0,
.write_flag_mask = 0,
.read_flag_mask = 0,
.reg_read = xrs700x_mdio_reg_read,
.reg_write = xrs700x_mdio_reg_write,
.max_register = XRS_VLAN(VLAN_N_VID - 1),
.cache_type = REGCACHE_NONE,
.reg_format_endian = REGMAP_ENDIAN_BIG,
.val_format_endian = REGMAP_ENDIAN_BIG
};
static int xrs700x_mdio_probe(struct mdio_device *mdiodev)
{
struct xrs700x *priv;
int ret;
priv = xrs700x_switch_alloc(&mdiodev->dev, mdiodev);
if (!priv)
return -ENOMEM;
priv->regmap = devm_regmap_init(&mdiodev->dev, NULL, mdiodev,
&xrs700x_mdio_regmap_config);
if (IS_ERR(priv->regmap)) {
ret = PTR_ERR(priv->regmap);
dev_err(&mdiodev->dev, "Failed to initialize regmap: %d\n", ret);
return ret;
}
dev_set_drvdata(&mdiodev->dev, priv);
ret = xrs700x_switch_register(priv);
/* Main DSA driver may not be started yet. */
if (ret)
return ret;
return 0;
}
static void xrs700x_mdio_remove(struct mdio_device *mdiodev)
{
struct xrs700x *priv = dev_get_drvdata(&mdiodev->dev);
if (!priv)
return;
xrs700x_switch_remove(priv);
dev_set_drvdata(&mdiodev->dev, NULL);
}
static void xrs700x_mdio_shutdown(struct mdio_device *mdiodev)
{
struct xrs700x *priv = dev_get_drvdata(&mdiodev->dev);
if (!priv)
return;
xrs700x_switch_shutdown(priv);
dev_set_drvdata(&mdiodev->dev, NULL);
}
static const struct of_device_id __maybe_unused xrs700x_mdio_dt_ids[] = {
{ .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
{ .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
{ .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
{ .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
{},
};
MODULE_DEVICE_TABLE(of, xrs700x_mdio_dt_ids);
static struct mdio_driver xrs700x_mdio_driver = {
.mdiodrv.driver = {
.name = "xrs700x-mdio",
.of_match_table = of_match_ptr(xrs700x_mdio_dt_ids),
},
.probe = xrs700x_mdio_probe,
.remove = xrs700x_mdio_remove,
.shutdown = xrs700x_mdio_shutdown,
};
mdio_module_driver(xrs700x_mdio_driver);
MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA MDIO driver");
MODULE_LICENSE("GPL v2");