u-boot/drivers/net/fm/memac_phy.c
Ioana Ciornei 64a0fb4cc3 net: memac_phy: add a timeout to MDIO operations
We have encountered circumstances when a board design does not include
pull-up resistors on the external MDIO buses which are not used. This
leads to the MDIO data line not being pulled-up, thus the MDIO controller
will always see the line as busy.

Without a timeout in the MDIO bus driver, the execution is stuck in an
infinite loop when any access is initiated on that external bus.

Add a timeout in the driver so that we are protected in this
circumstance. This is similar to what is being done in the Linux
xgmac_mdio driver.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
[Rebased]
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>
2021-02-08 14:01:14 +05:30

344 lines
8.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2012 Freescale Semiconductor, Inc.
* Andy Fleming <afleming@gmail.com>
* Roy Zang <tie-fei.zang@freescale.com>
* Some part is taken from tsec.c
*/
#include <common.h>
#include <miiphy.h>
#include <phy.h>
#include <asm/io.h>
#include <fsl_memac.h>
#include <fm_eth.h>
#ifdef CONFIG_SYS_MEMAC_LITTLE_ENDIAN
#define memac_out_32(a, v) out_le32(a, v)
#define memac_clrbits_32(a, v) clrbits_le32(a, v)
#define memac_setbits_32(a, v) setbits_le32(a, v)
#else
#define memac_out_32(a, v) out_be32(a, v)
#define memac_clrbits_32(a, v) clrbits_be32(a, v)
#define memac_setbits_32(a, v) setbits_be32(a, v)
#endif
#ifdef CONFIG_DM_ETH
struct fm_mdio_priv {
struct memac_mdio_controller *regs;
};
#endif
#define MAX_NUM_RETRIES 1000
static u32 memac_in_32(u32 *reg)
{
#ifdef CONFIG_SYS_MEMAC_LITTLE_ENDIAN
return in_le32(reg);
#else
return in_be32(reg);
#endif
}
/*
* Wait until the MDIO bus is free
*/
static int memac_wait_until_free(struct memac_mdio_controller *regs)
{
unsigned int timeout = MAX_NUM_RETRIES;
while ((memac_in_32(&regs->mdio_stat) & MDIO_STAT_BSY) && timeout--)
;
if (!timeout) {
printf("timeout waiting for MDIO bus to be free\n");
return -ETIMEDOUT;
}
return 0;
}
/*
* Wait till the MDIO read or write operation is complete
*/
static int memac_wait_until_done(struct memac_mdio_controller *regs)
{
unsigned int timeout = MAX_NUM_RETRIES;
while ((memac_in_32(&regs->mdio_data) & MDIO_DATA_BSY) && timeout--)
;
if (!timeout) {
printf("timeout waiting for MDIO 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
*/
int memac_mdio_write(struct mii_dev *bus, int port_addr, int dev_addr,
int regnum, u16 value)
{
struct memac_mdio_controller *regs;
u32 mdio_ctl;
u32 c45 = 1; /* Default to 10G interface */
int err;
#ifndef CONFIG_DM_ETH
regs = bus->priv;
#else
struct fm_mdio_priv *priv;
if (!bus->priv)
return -EINVAL;
priv = dev_get_priv(bus->priv);
regs = priv->regs;
debug("memac_mdio_write(regs %p, port %d, dev %d, reg %d, val %#x)\n",
regs, port_addr, dev_addr, regnum, value);
#endif
if (dev_addr == MDIO_DEVAD_NONE) {
c45 = 0; /* clause 22 */
dev_addr = regnum & 0x1f;
memac_clrbits_32(&regs->mdio_stat, MDIO_STAT_ENC);
} else
memac_setbits_32(&regs->mdio_stat, MDIO_STAT_ENC);
err = memac_wait_until_free(regs);
if (err)
return err;
/* Set the port and dev addr */
mdio_ctl = MDIO_CTL_PORT_ADDR(port_addr) | MDIO_CTL_DEV_ADDR(dev_addr);
memac_out_32(&regs->mdio_ctl, mdio_ctl);
/* Set the register address */
if (c45)
memac_out_32(&regs->mdio_addr, regnum & 0xffff);
err = memac_wait_until_free(regs);
if (err)
return err;
/* Write the value to the register */
memac_out_32(&regs->mdio_data, MDIO_DATA(value));
err = memac_wait_until_done(regs);
if (err)
return err;
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
*/
int memac_mdio_read(struct mii_dev *bus, int port_addr, int dev_addr,
int regnum)
{
struct memac_mdio_controller *regs;
u32 mdio_ctl;
u32 c45 = 1;
int err;
#ifndef CONFIG_DM_ETH
regs = bus->priv;
#else
struct fm_mdio_priv *priv;
if (!bus->priv)
return -EINVAL;
priv = dev_get_priv(bus->priv);
regs = priv->regs;
#endif
if (dev_addr == MDIO_DEVAD_NONE) {
#ifndef CONFIG_DM_ETH
if (!strcmp(bus->name, DEFAULT_FM_TGEC_MDIO_NAME))
return 0xffff;
#endif
c45 = 0; /* clause 22 */
dev_addr = regnum & 0x1f;
memac_clrbits_32(&regs->mdio_stat, MDIO_STAT_ENC);
} else
memac_setbits_32(&regs->mdio_stat, MDIO_STAT_ENC);
err = memac_wait_until_free(regs);
if (err)
return err;
/* Set the Port and Device Addrs */
mdio_ctl = MDIO_CTL_PORT_ADDR(port_addr) | MDIO_CTL_DEV_ADDR(dev_addr);
memac_out_32(&regs->mdio_ctl, mdio_ctl);
/* Set the register address */
if (c45)
memac_out_32(&regs->mdio_addr, regnum & 0xffff);
err = memac_wait_until_free(regs);
if (err)
return err;
/* Initiate the read */
mdio_ctl |= MDIO_CTL_READ;
memac_out_32(&regs->mdio_ctl, mdio_ctl);
err = memac_wait_until_done(regs);
if (err)
return err;
/* Return all Fs if nothing was there */
if (memac_in_32(&regs->mdio_stat) & MDIO_STAT_RD_ER)
return 0xffff;
return memac_in_32(&regs->mdio_data) & 0xffff;
}
int memac_mdio_reset(struct mii_dev *bus)
{
return 0;
}
#ifndef CONFIG_DM_ETH
int fm_memac_mdio_init(struct bd_info *bis, struct memac_mdio_info *info)
{
struct mii_dev *bus = mdio_alloc();
if (!bus) {
printf("Failed to allocate FM TGEC MDIO bus\n");
return -1;
}
bus->read = memac_mdio_read;
bus->write = memac_mdio_write;
bus->reset = memac_mdio_reset;
strcpy(bus->name, info->name);
bus->priv = info->regs;
/*
* On some platforms like B4860, default value of MDIO_CLK_DIV bits
* in mdio_stat(mdio_cfg) register generates MDIO clock too high
* (much higher than 2.5MHz), violating the IEEE specs.
* On other platforms like T1040, default value of MDIO_CLK_DIV bits
* is zero, so MDIO clock is disabled.
* So, for proper functioning of MDIO, MDIO_CLK_DIV bits needs to
* be properly initialized.
* NEG bit default should be '1' as per FMAN-v3 RM, but on platform
* like T2080QDS, this bit default is '0', which leads to MDIO failure
* on XAUI PHY, so set this bit definitely.
*/
memac_setbits_32(
&((struct memac_mdio_controller *)info->regs)->mdio_stat,
MDIO_STAT_CLKDIV(258) | MDIO_STAT_NEG);
return mdio_register(bus);
}
#else /* CONFIG_DM_ETH */
#if defined(CONFIG_PHYLIB) && defined(CONFIG_DM_MDIO)
static int fm_mdio_read(struct udevice *dev, int addr, int devad, int reg)
{
struct mdio_perdev_priv *pdata = (dev) ? dev_get_uclass_priv(dev) :
NULL;
if (pdata && pdata->mii_bus)
return memac_mdio_read(pdata->mii_bus, addr, devad, reg);
return -1;
}
static int fm_mdio_write(struct udevice *dev, int addr, int devad, int reg,
u16 val)
{
struct mdio_perdev_priv *pdata = (dev) ? dev_get_uclass_priv(dev) :
NULL;
if (pdata && pdata->mii_bus)
return memac_mdio_write(pdata->mii_bus, addr, devad, reg, val);
return -1;
}
static int fm_mdio_reset(struct udevice *dev)
{
struct mdio_perdev_priv *pdata = (dev) ? dev_get_uclass_priv(dev) :
NULL;
if (pdata && pdata->mii_bus)
return memac_mdio_reset(pdata->mii_bus);
return -1;
}
static const struct mdio_ops fm_mdio_ops = {
.read = fm_mdio_read,
.write = fm_mdio_write,
.reset = fm_mdio_reset,
};
static const struct udevice_id fm_mdio_ids[] = {
{ .compatible = "fsl,fman-memac-mdio" },
{}
};
static int fm_mdio_probe(struct udevice *dev)
{
struct fm_mdio_priv *priv = (dev) ? dev_get_priv(dev) : NULL;
struct mdio_perdev_priv *pdata = (dev) ? dev_get_uclass_priv(dev) :
NULL;
if (!dev) {
printf("%s dev = NULL\n", __func__);
return -1;
}
if (!priv) {
printf("dev_get_priv(dev %p) = NULL\n", dev);
return -1;
}
priv->regs = (void *)(uintptr_t)dev_read_addr(dev);
debug("%s priv %p @ regs %p, pdata %p\n", __func__,
priv, priv->regs, pdata);
/*
* On some platforms like B4860, default value of MDIO_CLK_DIV bits
* in mdio_stat(mdio_cfg) register generates MDIO clock too high
* (much higher than 2.5MHz), violating the IEEE specs.
* On other platforms like T1040, default value of MDIO_CLK_DIV bits
* is zero, so MDIO clock is disabled.
* So, for proper functioning of MDIO, MDIO_CLK_DIV bits needs to
* be properly initialized.
* The default NEG bit should be '1' as per FMANv3 RM, but on platforms
* like T2080QDS, this bit default is '0', which leads to MDIO failure
* on XAUI PHY, so set this bit definitely.
*/
if (priv && priv->regs && priv->regs->mdio_stat)
memac_setbits_32(&priv->regs->mdio_stat,
MDIO_STAT_CLKDIV(258) | MDIO_STAT_NEG);
return 0;
}
static int fm_mdio_remove(struct udevice *dev)
{
return 0;
}
U_BOOT_DRIVER(fman_mdio) = {
.name = "fman_mdio",
.id = UCLASS_MDIO,
.of_match = fm_mdio_ids,
.probe = fm_mdio_probe,
.remove = fm_mdio_remove,
.ops = &fm_mdio_ops,
.priv_auto = sizeof(struct fm_mdio_priv),
.plat_auto = sizeof(struct mdio_perdev_priv),
};
#endif /* CONFIG_PHYLIB && CONFIG_DM_MDIO */
#endif /* CONFIG_DM_ETH */