https://github.com/torvalds/linux
Tip revision: 2241ab53cbb5cdb08a6b2d4688feb13971058f65 authored by Linus Torvalds on 22 January 2023, 00:27:01 UTC
Linux 6.2-rc5
Linux 6.2-rc5
Tip revision: 2241ab5
xgmac_mdio.c
/*
* QorIQ 10G MDIO Controller
*
* Copyright 2012 Freescale Semiconductor, Inc.
* Copyright 2021 NXP
*
* Authors: Andy Fleming <afleming@freescale.com>
* Timur Tabi <timur@freescale.com>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/acpi.h>
#include <linux/acpi_mdio.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mdio.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_mdio.h>
#include <linux/of_platform.h>
#include <linux/phy.h>
#include <linux/slab.h>
/* Number of microseconds to wait for a register to respond */
#define TIMEOUT 1000
struct tgec_mdio_controller {
__be32 reserved[12];
__be32 mdio_stat; /* MDIO configuration and status */
__be32 mdio_ctl; /* MDIO control */
__be32 mdio_data; /* MDIO data */
__be32 mdio_addr; /* MDIO address */
} __packed;
#define MDIO_STAT_ENC BIT(6)
#define MDIO_STAT_CLKDIV(x) (((x) & 0x1ff) << 7)
#define MDIO_STAT_BSY BIT(0)
#define MDIO_STAT_RD_ER BIT(1)
#define MDIO_STAT_PRE_DIS BIT(5)
#define MDIO_CTL_DEV_ADDR(x) (x & 0x1f)
#define MDIO_CTL_PORT_ADDR(x) ((x & 0x1f) << 5)
#define MDIO_CTL_PRE_DIS BIT(10)
#define MDIO_CTL_SCAN_EN BIT(11)
#define MDIO_CTL_POST_INC BIT(14)
#define MDIO_CTL_READ BIT(15)
#define MDIO_DATA(x) (x & 0xffff)
struct mdio_fsl_priv {
struct tgec_mdio_controller __iomem *mdio_base;
struct clk *enet_clk;
u32 mdc_freq;
bool is_little_endian;
bool has_a009885;
bool has_a011043;
};
static u32 xgmac_read32(void __iomem *regs,
bool is_little_endian)
{
if (is_little_endian)
return ioread32(regs);
else
return ioread32be(regs);
}
static void xgmac_write32(u32 value,
void __iomem *regs,
bool is_little_endian)
{
if (is_little_endian)
iowrite32(value, regs);
else
iowrite32be(value, regs);
}
/*
* Wait until the MDIO bus is free
*/
static int xgmac_wait_until_free(struct device *dev,
struct tgec_mdio_controller __iomem *regs,
bool is_little_endian)
{
unsigned int timeout;
/* Wait till the bus is free */
timeout = TIMEOUT;
while ((xgmac_read32(®s->mdio_stat, is_little_endian) &
MDIO_STAT_BSY) && timeout) {
cpu_relax();
timeout--;
}
if (!timeout) {
dev_err(dev, "timeout waiting for bus to be free\n");
return -ETIMEDOUT;
}
return 0;
}
/*
* Wait till the MDIO read or write operation is complete
*/
static int xgmac_wait_until_done(struct device *dev,
struct tgec_mdio_controller __iomem *regs,
bool is_little_endian)
{
unsigned int timeout;
/* Wait till the MDIO write is complete */
timeout = TIMEOUT;
while ((xgmac_read32(®s->mdio_stat, is_little_endian) &
MDIO_STAT_BSY) && timeout) {
cpu_relax();
timeout--;
}
if (!timeout) {
dev_err(dev, "timeout waiting for operation to complete\n");
return -ETIMEDOUT;
}
return 0;
}
/*
* Write value to the PHY for this device to the register at regnum,waiting
* until the write is done before it returns. All PHY configuration has to be
* done through the TSEC1 MIIM regs.
*/
static int xgmac_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
{
struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
uint16_t dev_addr;
u32 mdio_ctl, mdio_stat;
int ret;
bool endian = priv->is_little_endian;
mdio_stat = xgmac_read32(®s->mdio_stat, endian);
if (regnum & MII_ADDR_C45) {
/* Clause 45 (ie 10G) */
dev_addr = (regnum >> 16) & 0x1f;
mdio_stat |= MDIO_STAT_ENC;
} else {
/* Clause 22 (ie 1G) */
dev_addr = regnum & 0x1f;
mdio_stat &= ~MDIO_STAT_ENC;
}
xgmac_write32(mdio_stat, ®s->mdio_stat, endian);
ret = xgmac_wait_until_free(&bus->dev, regs, endian);
if (ret)
return ret;
/* Set the port and dev addr */
mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
xgmac_write32(mdio_ctl, ®s->mdio_ctl, endian);
/* Set the register address */
if (regnum & MII_ADDR_C45) {
xgmac_write32(regnum & 0xffff, ®s->mdio_addr, endian);
ret = xgmac_wait_until_free(&bus->dev, regs, endian);
if (ret)
return ret;
}
/* Write the value to the register */
xgmac_write32(MDIO_DATA(value), ®s->mdio_data, endian);
ret = xgmac_wait_until_done(&bus->dev, regs, endian);
if (ret)
return ret;
return 0;
}
/*
* Reads from register regnum in the PHY for device dev, returning the value.
* Clears miimcom first. All PHY configuration has to be done through the
* TSEC1 MIIM regs.
*/
static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
{
struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
unsigned long flags;
uint16_t dev_addr;
uint32_t mdio_stat;
uint32_t mdio_ctl;
int ret;
bool endian = priv->is_little_endian;
mdio_stat = xgmac_read32(®s->mdio_stat, endian);
if (regnum & MII_ADDR_C45) {
dev_addr = (regnum >> 16) & 0x1f;
mdio_stat |= MDIO_STAT_ENC;
} else {
dev_addr = regnum & 0x1f;
mdio_stat &= ~MDIO_STAT_ENC;
}
xgmac_write32(mdio_stat, ®s->mdio_stat, endian);
ret = xgmac_wait_until_free(&bus->dev, regs, endian);
if (ret)
return ret;
/* Set the Port and Device Addrs */
mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
xgmac_write32(mdio_ctl, ®s->mdio_ctl, endian);
/* Set the register address */
if (regnum & MII_ADDR_C45) {
xgmac_write32(regnum & 0xffff, ®s->mdio_addr, endian);
ret = xgmac_wait_until_free(&bus->dev, regs, endian);
if (ret)
return ret;
}
if (priv->has_a009885)
/* Once the operation completes, i.e. MDIO_STAT_BSY clears, we
* must read back the data register within 16 MDC cycles.
*/
local_irq_save(flags);
/* Initiate the read */
xgmac_write32(mdio_ctl | MDIO_CTL_READ, ®s->mdio_ctl, endian);
ret = xgmac_wait_until_done(&bus->dev, regs, endian);
if (ret)
goto irq_restore;
/* Return all Fs if nothing was there */
if ((xgmac_read32(®s->mdio_stat, endian) & MDIO_STAT_RD_ER) &&
!priv->has_a011043) {
dev_dbg(&bus->dev,
"Error while reading PHY%d reg at %d.%d\n",
phy_id, dev_addr, regnum);
ret = 0xffff;
} else {
ret = xgmac_read32(®s->mdio_data, endian) & 0xffff;
dev_dbg(&bus->dev, "read %04x\n", ret);
}
irq_restore:
if (priv->has_a009885)
local_irq_restore(flags);
return ret;
}
static int xgmac_mdio_set_mdc_freq(struct mii_bus *bus)
{
struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
struct device *dev = bus->parent;
u32 mdio_stat, div;
if (device_property_read_u32(dev, "clock-frequency", &priv->mdc_freq))
return 0;
priv->enet_clk = devm_clk_get(dev, NULL);
if (IS_ERR(priv->enet_clk)) {
dev_err(dev, "Input clock unknown, not changing MDC frequency");
return PTR_ERR(priv->enet_clk);
}
div = ((clk_get_rate(priv->enet_clk) / priv->mdc_freq) - 1) / 2;
if (div < 5 || div > 0x1ff) {
dev_err(dev, "Requested MDC frequency is out of range, ignoring");
return -EINVAL;
}
mdio_stat = xgmac_read32(®s->mdio_stat, priv->is_little_endian);
mdio_stat &= ~MDIO_STAT_CLKDIV(0x1ff);
mdio_stat |= MDIO_STAT_CLKDIV(div);
xgmac_write32(mdio_stat, ®s->mdio_stat, priv->is_little_endian);
return 0;
}
static void xgmac_mdio_set_suppress_preamble(struct mii_bus *bus)
{
struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
struct device *dev = bus->parent;
u32 mdio_stat;
if (!device_property_read_bool(dev, "suppress-preamble"))
return;
mdio_stat = xgmac_read32(®s->mdio_stat, priv->is_little_endian);
mdio_stat |= MDIO_STAT_PRE_DIS;
xgmac_write32(mdio_stat, ®s->mdio_stat, priv->is_little_endian);
}
static int xgmac_mdio_probe(struct platform_device *pdev)
{
struct fwnode_handle *fwnode;
struct mdio_fsl_priv *priv;
struct resource *res;
struct mii_bus *bus;
int ret;
/* In DPAA-1, MDIO is one of the many FMan sub-devices. The FMan
* defines a register space that spans a large area, covering all the
* subdevice areas. Therefore, MDIO cannot claim exclusive access to
* this register area.
*/
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "could not obtain address\n");
return -EINVAL;
}
bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(struct mdio_fsl_priv));
if (!bus)
return -ENOMEM;
bus->name = "Freescale XGMAC MDIO Bus";
bus->read = xgmac_mdio_read;
bus->write = xgmac_mdio_write;
bus->parent = &pdev->dev;
bus->probe_capabilities = MDIOBUS_C22_C45;
snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res->start);
priv = bus->priv;
priv->mdio_base = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
if (!priv->mdio_base)
return -ENOMEM;
/* For both ACPI and DT cases, endianness of MDIO controller
* needs to be specified using "little-endian" property.
*/
priv->is_little_endian = device_property_read_bool(&pdev->dev,
"little-endian");
priv->has_a009885 = device_property_read_bool(&pdev->dev,
"fsl,erratum-a009885");
priv->has_a011043 = device_property_read_bool(&pdev->dev,
"fsl,erratum-a011043");
xgmac_mdio_set_suppress_preamble(bus);
ret = xgmac_mdio_set_mdc_freq(bus);
if (ret)
return ret;
fwnode = dev_fwnode(&pdev->dev);
if (is_of_node(fwnode))
ret = of_mdiobus_register(bus, to_of_node(fwnode));
else if (is_acpi_node(fwnode))
ret = acpi_mdiobus_register(bus, fwnode);
else
ret = -EINVAL;
if (ret) {
dev_err(&pdev->dev, "cannot register MDIO bus\n");
return ret;
}
platform_set_drvdata(pdev, bus);
return 0;
}
static const struct of_device_id xgmac_mdio_match[] = {
{
.compatible = "fsl,fman-xmdio",
},
{
.compatible = "fsl,fman-memac-mdio",
},
{},
};
MODULE_DEVICE_TABLE(of, xgmac_mdio_match);
static const struct acpi_device_id xgmac_acpi_match[] = {
{ "NXP0006" },
{ }
};
MODULE_DEVICE_TABLE(acpi, xgmac_acpi_match);
static struct platform_driver xgmac_mdio_driver = {
.driver = {
.name = "fsl-fman_xmdio",
.of_match_table = xgmac_mdio_match,
.acpi_match_table = xgmac_acpi_match,
},
.probe = xgmac_mdio_probe,
};
module_platform_driver(xgmac_mdio_driver);
MODULE_DESCRIPTION("Freescale QorIQ 10G MDIO Controller");
MODULE_LICENSE("GPL v2");