// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
*/
/* Qualcomm Technologies, Inc. EMAC PHY Controller driver.
*/
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/iopoll.h>
#include <linux/acpi.h>
#include "emac.h"
/* EMAC base register offsets */
#define EMAC_MDIO_CTRL 0x001414
#define EMAC_PHY_STS 0x001418
#define EMAC_MDIO_EX_CTRL 0x001440
/* EMAC_MDIO_CTRL */
#define MDIO_MODE BIT(30)
#define MDIO_PR BIT(29)
#define MDIO_AP_EN BIT(28)
#define MDIO_BUSY BIT(27)
#define MDIO_CLK_SEL_BMSK 0x7000000
#define MDIO_CLK_SEL_SHFT 24
#define MDIO_START BIT(23)
#define SUP_PREAMBLE BIT(22)
#define MDIO_RD_NWR BIT(21)
#define MDIO_REG_ADDR_BMSK 0x1f0000
#define MDIO_REG_ADDR_SHFT 16
#define MDIO_DATA_BMSK 0xffff
#define MDIO_DATA_SHFT 0
/* EMAC_PHY_STS */
#define PHY_ADDR_BMSK 0x1f0000
#define PHY_ADDR_SHFT 16
#define MDIO_CLK_25_4 0
#define MDIO_CLK_25_28 7
#define MDIO_WAIT_TIMES 1000
#define MDIO_STATUS_DELAY_TIME 1
static int emac_mdio_read(struct mii_bus *bus, int addr, int regnum)
{
struct emac_adapter *adpt = bus->priv;
u32 reg;
emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK,
(addr << PHY_ADDR_SHFT));
reg = SUP_PREAMBLE |
((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) |
((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) |
MDIO_START | MDIO_RD_NWR;
writel(reg, adpt->base + EMAC_MDIO_CTRL);
if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg,
!(reg & (MDIO_START | MDIO_BUSY)),
MDIO_STATUS_DELAY_TIME, MDIO_WAIT_TIMES * 100))
return -EIO;
return (reg >> MDIO_DATA_SHFT) & MDIO_DATA_BMSK;
}
static int emac_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
{
struct emac_adapter *adpt = bus->priv;
u32 reg;
emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK,
(addr << PHY_ADDR_SHFT));
reg = SUP_PREAMBLE |
((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) |
((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) |
((val << MDIO_DATA_SHFT) & MDIO_DATA_BMSK) |
MDIO_START;
writel(reg, adpt->base + EMAC_MDIO_CTRL);
if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg,
!(reg & (MDIO_START | MDIO_BUSY)),
MDIO_STATUS_DELAY_TIME, MDIO_WAIT_TIMES * 100))
return -EIO;
return 0;
}
/* Configure the MDIO bus and connect the external PHY */
int emac_phy_config(struct platform_device *pdev, struct emac_adapter *adpt)
{
struct device_node *np = pdev->dev.of_node;
struct mii_bus *mii_bus;
int ret;
/* Create the mii_bus object for talking to the MDIO bus */
adpt->mii_bus = mii_bus = devm_mdiobus_alloc(&pdev->dev);
if (!mii_bus)
return -ENOMEM;
mii_bus->name = "emac-mdio";
snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
mii_bus->read = emac_mdio_read;
mii_bus->write = emac_mdio_write;
mii_bus->parent = &pdev->dev;
mii_bus->priv = adpt;
if (has_acpi_companion(&pdev->dev)) {
u32 phy_addr;
ret = mdiobus_register(mii_bus);
if (ret) {
dev_err(&pdev->dev, "could not register mdio bus\n");
return ret;
}
ret = device_property_read_u32(&pdev->dev, "phy-channel",
&phy_addr);
if (ret)
/* If we can't read a valid phy address, then assume
* that there is only one phy on this mdio bus.
*/
adpt->phydev = phy_find_first(mii_bus);
else
adpt->phydev = mdiobus_get_phy(mii_bus, phy_addr);
/* of_phy_find_device() claims a reference to the phydev,
* so we do that here manually as well. When the driver
* later unloads, it can unilaterally drop the reference
* without worrying about ACPI vs DT.
*/
if (adpt->phydev)
get_device(&adpt->phydev->mdio.dev);
} else {
struct device_node *phy_np;
ret = of_mdiobus_register(mii_bus, np);
if (ret) {
dev_err(&pdev->dev, "could not register mdio bus\n");
return ret;
}
phy_np = of_parse_phandle(np, "phy-handle", 0);
adpt->phydev = of_phy_find_device(phy_np);
of_node_put(phy_np);
}
if (!adpt->phydev) {
dev_err(&pdev->dev, "could not find external phy\n");
mdiobus_unregister(mii_bus);
return -ENODEV;
}
return 0;
}