blob: 1ee592d3eae46dc0a755c534134c25664ac0dbe8 [file] [log] [blame]
// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* Driver for the MDIO interface of Microsemi network switches.
*
* Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
* Copyright (c) 2017 Microsemi Corporation
*/
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#define MSCC_MIIM_REG_STATUS 0x0
#define MSCC_MIIM_STATUS_STAT_PENDING BIT(2)
#define MSCC_MIIM_STATUS_STAT_BUSY BIT(3)
#define MSCC_MIIM_REG_CMD 0x8
#define MSCC_MIIM_CMD_OPR_WRITE BIT(1)
#define MSCC_MIIM_CMD_OPR_READ BIT(2)
#define MSCC_MIIM_CMD_WRDATA_SHIFT 4
#define MSCC_MIIM_CMD_REGAD_SHIFT 20
#define MSCC_MIIM_CMD_PHYAD_SHIFT 25
#define MSCC_MIIM_CMD_VLD BIT(31)
#define MSCC_MIIM_REG_DATA 0xC
#define MSCC_MIIM_DATA_ERROR (BIT(16) | BIT(17))
#define MSCC_PHY_REG_PHY_CFG 0x0
#define PHY_CFG_PHY_ENA (BIT(0) | BIT(1) | BIT(2) | BIT(3))
#define PHY_CFG_PHY_COMMON_RESET BIT(4)
#define PHY_CFG_PHY_RESET (BIT(5) | BIT(6) | BIT(7) | BIT(8))
#define MSCC_PHY_REG_PHY_STATUS 0x4
struct mscc_miim_dev {
void __iomem *regs;
void __iomem *phy_regs;
};
/* When high resolution timers aren't built-in: we can't use usleep_range() as
* we would sleep way too long. Use udelay() instead.
*/
#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
({ \
if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \
readl_poll_timeout_atomic(addr, val, cond, delay_us, \
timeout_us); \
readl_poll_timeout(addr, val, cond, delay_us, timeout_us); \
})
static int mscc_miim_wait_ready(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
u32 val;
return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
!(val & MSCC_MIIM_STATUS_STAT_BUSY), 50,
10000);
}
static int mscc_miim_wait_pending(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
u32 val;
return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
!(val & MSCC_MIIM_STATUS_STAT_PENDING),
50, 10000);
}
static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
{
struct mscc_miim_dev *miim = bus->priv;
u32 val;
int ret;
ret = mscc_miim_wait_pending(bus);
if (ret)
goto out;
writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ,
miim->regs + MSCC_MIIM_REG_CMD);
ret = mscc_miim_wait_ready(bus);
if (ret)
goto out;
val = readl(miim->regs + MSCC_MIIM_REG_DATA);
if (val & MSCC_MIIM_DATA_ERROR) {
ret = -EIO;
goto out;
}
ret = val & 0xFFFF;
out:
return ret;
}
static int mscc_miim_write(struct mii_bus *bus, int mii_id,
int regnum, u16 value)
{
struct mscc_miim_dev *miim = bus->priv;
int ret;
ret = mscc_miim_wait_pending(bus);
if (ret < 0)
goto out;
writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
(value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
MSCC_MIIM_CMD_OPR_WRITE,
miim->regs + MSCC_MIIM_REG_CMD);
out:
return ret;
}
static int mscc_miim_reset(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
if (miim->phy_regs) {
writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
mdelay(500);
}
return 0;
}
static int mscc_miim_probe(struct platform_device *pdev)
{
struct mii_bus *bus;
struct mscc_miim_dev *dev;
int ret;
bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev));
if (!bus)
return -ENOMEM;
bus->name = "mscc_miim";
bus->read = mscc_miim_read;
bus->write = mscc_miim_write;
bus->reset = mscc_miim_reset;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
bus->parent = &pdev->dev;
dev = bus->priv;
dev->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
if (IS_ERR(dev->regs)) {
dev_err(&pdev->dev, "Unable to map MIIM registers\n");
return PTR_ERR(dev->regs);
}
dev->phy_regs = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(dev->phy_regs)) {
dev_err(&pdev->dev, "Unable to map internal phy registers\n");
return PTR_ERR(dev->phy_regs);
}
ret = of_mdiobus_register(bus, pdev->dev.of_node);
if (ret < 0) {
dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
return ret;
}
platform_set_drvdata(pdev, bus);
return 0;
}
static int mscc_miim_remove(struct platform_device *pdev)
{
struct mii_bus *bus = platform_get_drvdata(pdev);
mdiobus_unregister(bus);
return 0;
}
static const struct of_device_id mscc_miim_match[] = {
{ .compatible = "mscc,ocelot-miim" },
{ }
};
MODULE_DEVICE_TABLE(of, mscc_miim_match);
static struct platform_driver mscc_miim_driver = {
.probe = mscc_miim_probe,
.remove = mscc_miim_remove,
.driver = {
.name = "mscc-miim",
.of_match_table = mscc_miim_match,
},
};
module_platform_driver(mscc_miim_driver);
MODULE_DESCRIPTION("Microsemi MIIM driver");
MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
MODULE_LICENSE("Dual MIT/GPL");