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// SPDX-License-Identifier: GPL-2.0+
/*
* Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
*
* Author: Vitaly Bordug <vbordug@ru.mvista.com>
* Anton Vorontsov <avorontsov@ru.mvista.com>
*
* Copyright (c) 2006-2007 MontaVista Software, Inc.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/list.h>
#include <linux/mii.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/gpio/consumer.h>
#include <linux/seqlock.h>
#include <linux/idr.h>
#include <linux/netdevice.h>
#include <linux/linkmode.h>
#include "swphy.h"
struct fixed_mdio_bus {
struct mii_bus *mii_bus;
struct list_head phys;
};
struct fixed_phy {
int addr;
struct phy_device *phydev;
seqcount_t seqcount;
struct fixed_phy_status status;
bool no_carrier;
int (*link_update)(struct net_device *, struct fixed_phy_status *);
struct list_head node;
struct gpio_desc *link_gpiod;
};
static struct platform_device *pdev;
static struct fixed_mdio_bus platform_fmb = {
.phys = LIST_HEAD_INIT(platform_fmb.phys),
};
int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier)
{
struct fixed_mdio_bus *fmb = &platform_fmb;
struct phy_device *phydev = dev->phydev;
struct fixed_phy *fp;
if (!phydev || !phydev->mdio.bus)
return -EINVAL;
list_for_each_entry(fp, &fmb->phys, node) {
if (fp->addr == phydev->mdio.addr) {
fp->no_carrier = !new_carrier;
return 0;
}
}
return -EINVAL;
}
EXPORT_SYMBOL_GPL(fixed_phy_change_carrier);
static void fixed_phy_update(struct fixed_phy *fp)
{
if (!fp->no_carrier && fp->link_gpiod)
fp->status.link = !!gpiod_get_value_cansleep(fp->link_gpiod);
}
static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
{
struct fixed_mdio_bus *fmb = bus->priv;
struct fixed_phy *fp;
list_for_each_entry(fp, &fmb->phys, node) {
if (fp->addr == phy_addr) {
struct fixed_phy_status state;
int s;
do {
s = read_seqcount_begin(&fp->seqcount);
fp->status.link = !fp->no_carrier;
/* Issue callback if user registered it. */
if (fp->link_update)
fp->link_update(fp->phydev->attached_dev,
&fp->status);
/* Check the GPIO for change in status */
fixed_phy_update(fp);
state = fp->status;
} while (read_seqcount_retry(&fp->seqcount, s));
return swphy_read_reg(reg_num, &state);
}
}
return 0xFFFF;
}
static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num,
u16 val)
{
return 0;
}
/*
* If something weird is required to be done with link/speed,
* network driver is able to assign a function to implement this.
* May be useful for PHY's that need to be software-driven.
*/
int fixed_phy_set_link_update(struct phy_device *phydev,
int (*link_update)(struct net_device *,
struct fixed_phy_status *))
{
struct fixed_mdio_bus *fmb = &platform_fmb;
struct fixed_phy *fp;
if (!phydev || !phydev->mdio.bus)
return -EINVAL;
list_for_each_entry(fp, &fmb->phys, node) {
if (fp->addr == phydev->mdio.addr) {
fp->link_update = link_update;
fp->phydev = phydev;
return 0;
}
}
return -ENOENT;
}
EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);
static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr,
struct fixed_phy_status *status,
struct gpio_desc *gpiod)
{
int ret;
struct fixed_mdio_bus *fmb = &platform_fmb;
struct fixed_phy *fp;
ret = swphy_validate_state(status);
if (ret < 0)
return ret;
fp = kzalloc(sizeof(*fp), GFP_KERNEL);
if (!fp)
return -ENOMEM;
seqcount_init(&fp->seqcount);
if (irq != PHY_POLL)
fmb->mii_bus->irq[phy_addr] = irq;
fp->addr = phy_addr;
fp->status = *status;
fp->link_gpiod = gpiod;
fixed_phy_update(fp);
list_add_tail(&fp->node, &fmb->phys);
return 0;
}
int fixed_phy_add(unsigned int irq, int phy_addr,
struct fixed_phy_status *status) {
return fixed_phy_add_gpiod(irq, phy_addr, status, NULL);
}
EXPORT_SYMBOL_GPL(fixed_phy_add);
static DEFINE_IDA(phy_fixed_ida);
static void fixed_phy_del(int phy_addr)
{
struct fixed_mdio_bus *fmb = &platform_fmb;
struct fixed_phy *fp, *tmp;
list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
if (fp->addr == phy_addr) {
list_del(&fp->node);
if (fp->link_gpiod)
gpiod_put(fp->link_gpiod);
kfree(fp);
ida_simple_remove(&phy_fixed_ida, phy_addr);
return;
}
}
}
#ifdef CONFIG_OF_GPIO
static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
{
struct device_node *fixed_link_node;
struct gpio_desc *gpiod;
if (!np)
return NULL;
fixed_link_node = of_get_child_by_name(np, "fixed-link");
if (!fixed_link_node)
return NULL;
/*
* As the fixed link is just a device tree node without any
* Linux device associated with it, we simply have obtain
* the GPIO descriptor from the device tree like this.
*/
gpiod = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0,
GPIOD_IN, "mdio");
of_node_put(fixed_link_node);
if (IS_ERR(gpiod)) {
if (PTR_ERR(gpiod) == -EPROBE_DEFER)
return gpiod;
pr_err("error getting GPIO for fixed link %pOF, proceed without\n",
fixed_link_node);
gpiod = NULL;
}
return gpiod;
}
#else
static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np)
{
return NULL;
}
#endif
static struct phy_device *__fixed_phy_register(unsigned int irq,
struct fixed_phy_status *status,
struct device_node *np,
struct gpio_desc *gpiod)
{
struct fixed_mdio_bus *fmb = &platform_fmb;
struct phy_device *phy;
int phy_addr;
int ret;
if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED)
return ERR_PTR(-EPROBE_DEFER);
/* Check if we have a GPIO associated with this fixed phy */
if (!gpiod) {
gpiod = fixed_phy_get_gpiod(np);
if (IS_ERR(gpiod))
return ERR_CAST(gpiod);
}
/* Get the next available PHY address, up to PHY_MAX_ADDR */
phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL);
if (phy_addr < 0)
return ERR_PTR(phy_addr);
ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod);
if (ret < 0) {
ida_simple_remove(&phy_fixed_ida, phy_addr);
return ERR_PTR(ret);
}
phy = get_phy_device(fmb->mii_bus, phy_addr, false);
if (IS_ERR(phy)) {
fixed_phy_del(phy_addr);
return ERR_PTR(-EINVAL);
}
/* propagate the fixed link values to struct phy_device */
phy->link = status->link;
if (status->link) {
phy->speed = status->speed;
phy->duplex = status->duplex;
phy->pause = status->pause;
phy->asym_pause = status->asym_pause;
}
of_node_get(np);
phy->mdio.dev.of_node = np;
phy->is_pseudo_fixed_link = true;
switch (status->speed) {
case SPEED_1000:
linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
phy->supported);
linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
phy->supported);
/* fall through */
case SPEED_100:
linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
phy->supported);
linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
phy->supported);
/* fall through */
case SPEED_10:
default:
linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
phy->supported);
linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
phy->supported);
}
linkmode_copy(phy->advertising, phy->supported);
ret = phy_device_register(phy);
if (ret) {
phy_device_free(phy);
of_node_put(np);
fixed_phy_del(phy_addr);
return ERR_PTR(ret);
}
return phy;
}
struct phy_device *fixed_phy_register(unsigned int irq,
struct fixed_phy_status *status,
struct device_node *np)
{
return __fixed_phy_register(irq, status, np, NULL);
}
EXPORT_SYMBOL_GPL(fixed_phy_register);
struct phy_device *
fixed_phy_register_with_gpiod(unsigned int irq,
struct fixed_phy_status *status,
struct gpio_desc *gpiod)
{
return __fixed_phy_register(irq, status, NULL, gpiod);
}
EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod);
void fixed_phy_unregister(struct phy_device *phy)
{
phy_device_remove(phy);
of_node_put(phy->mdio.dev.of_node);
fixed_phy_del(phy->mdio.addr);
}
EXPORT_SYMBOL_GPL(fixed_phy_unregister);
static int __init fixed_mdio_bus_init(void)
{
struct fixed_mdio_bus *fmb = &platform_fmb;
int ret;
pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
fmb->mii_bus = mdiobus_alloc();
if (fmb->mii_bus == NULL) {
ret = -ENOMEM;
goto err_mdiobus_reg;
}
snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
fmb->mii_bus->name = "Fixed MDIO Bus";
fmb->mii_bus->priv = fmb;
fmb->mii_bus->parent = &pdev->dev;
fmb->mii_bus->read = &fixed_mdio_read;
fmb->mii_bus->write = &fixed_mdio_write;
ret = mdiobus_register(fmb->mii_bus);
if (ret)
goto err_mdiobus_alloc;
return 0;
err_mdiobus_alloc:
mdiobus_free(fmb->mii_bus);
err_mdiobus_reg:
platform_device_unregister(pdev);
return ret;
}
module_init(fixed_mdio_bus_init);
static void __exit fixed_mdio_bus_exit(void)
{
struct fixed_mdio_bus *fmb = &platform_fmb;
struct fixed_phy *fp, *tmp;
mdiobus_unregister(fmb->mii_bus);
mdiobus_free(fmb->mii_bus);
platform_device_unregister(pdev);
list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
list_del(&fp->node);
kfree(fp);
}
ida_destroy(&phy_fixed_ida);
}
module_exit(fixed_mdio_bus_exit);
MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
MODULE_AUTHOR("Vitaly Bordug");
MODULE_LICENSE("GPL");