/*
* Copyright (C) 2015 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#define IPROC_GPHY_MDCDIV 0x1a
#define MII_CTRL_OFFSET 0x000
#define MII_CTRL_DIV_SHIFT 0
#define MII_CTRL_PRE_SHIFT 7
#define MII_CTRL_BUSY_SHIFT 8
#define MII_DATA_OFFSET 0x004
#define MII_DATA_MASK 0xffff
#define MII_DATA_TA_SHIFT 16
#define MII_DATA_TA_VAL 2
#define MII_DATA_RA_SHIFT 18
#define MII_DATA_PA_SHIFT 23
#define MII_DATA_OP_SHIFT 28
#define MII_DATA_OP_WRITE 1
#define MII_DATA_OP_READ 2
#define MII_DATA_SB_SHIFT 30
struct iproc_mdio_priv {
struct mii_bus *mii_bus;
void __iomem *base;
};
static inline int iproc_mdio_wait_for_idle(void __iomem *base)
{
u32 val;
unsigned int timeout = 1000; /* loop for 1s */
do {
val = readl(base + MII_CTRL_OFFSET);
if ((val & BIT(MII_CTRL_BUSY_SHIFT)) == 0)
return 0;
usleep_range(1000, 2000);
} while (timeout--);
return -ETIMEDOUT;
}
static inline void iproc_mdio_config_clk(void __iomem *base)
{
u32 val;
val = (IPROC_GPHY_MDCDIV << MII_CTRL_DIV_SHIFT) |
BIT(MII_CTRL_PRE_SHIFT);
writel(val, base + MII_CTRL_OFFSET);
}
static int iproc_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
struct iproc_mdio_priv *priv = bus->priv;
u32 cmd;
int rc;
rc = iproc_mdio_wait_for_idle(priv->base);
if (rc)
return rc;
iproc_mdio_config_clk(priv->base);
/* Prepare the read operation */
cmd = (MII_DATA_TA_VAL << MII_DATA_TA_SHIFT) |
(reg << MII_DATA_RA_SHIFT) |
(phy_id << MII_DATA_PA_SHIFT) |
BIT(MII_DATA_SB_SHIFT) |
(MII_DATA_OP_READ << MII_DATA_OP_SHIFT);
writel(cmd, priv->base + MII_DATA_OFFSET);
rc = iproc_mdio_wait_for_idle(priv->base);
if (rc)
return rc;
cmd = readl(priv->base + MII_DATA_OFFSET) & MII_DATA_MASK;
return cmd;
}
static int iproc_mdio_write(struct mii_bus *bus, int phy_id,
int reg, u16 val)
{
struct iproc_mdio_priv *priv = bus->priv;
u32 cmd;
int rc;
rc = iproc_mdio_wait_for_idle(priv->base);
if (rc)
return rc;
iproc_mdio_config_clk(priv->base);
/* Prepare the write operation */
cmd = (MII_DATA_TA_VAL << MII_DATA_TA_SHIFT) |
(reg << MII_DATA_RA_SHIFT) |
(phy_id << MII_DATA_PA_SHIFT) |
BIT(MII_DATA_SB_SHIFT) |
(MII_DATA_OP_WRITE << MII_DATA_OP_SHIFT) |
((u32)(val) & MII_DATA_MASK);
writel(cmd, priv->base + MII_DATA_OFFSET);
rc = iproc_mdio_wait_for_idle(priv->base);
if (rc)
return rc;
return 0;
}
static int iproc_mdio_probe(struct platform_device *pdev)
{
struct iproc_mdio_priv *priv;
struct mii_bus *bus;
struct resource *res;
int rc;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->base)) {
dev_err(&pdev->dev, "failed to ioremap register\n");
return PTR_ERR(priv->base);
}
priv->mii_bus = mdiobus_alloc();
if (!priv->mii_bus) {
dev_err(&pdev->dev, "MDIO bus alloc failed\n");
return -ENOMEM;
}
bus = priv->mii_bus;
bus->priv = priv;
bus->name = "iProc MDIO bus";
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
bus->parent = &pdev->dev;
bus->read = iproc_mdio_read;
bus->write = iproc_mdio_write;
rc = of_mdiobus_register(bus, pdev->dev.of_node);
if (rc) {
dev_err(&pdev->dev, "MDIO bus registration failed\n");
goto err_iproc_mdio;
}
platform_set_drvdata(pdev, priv);
dev_info(&pdev->dev, "Broadcom iProc MDIO bus at 0x%p\n", priv->base);
return 0;
err_iproc_mdio:
mdiobus_free(bus);
return rc;
}
static int iproc_mdio_remove(struct platform_device *pdev)
{
struct iproc_mdio_priv *priv = platform_get_drvdata(pdev);
mdiobus_unregister(priv->mii_bus);
mdiobus_free(priv->mii_bus);
return 0;
}
static const struct of_device_id iproc_mdio_of_match[] = {
{ .compatible = "brcm,iproc-mdio", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, iproc_mdio_of_match);
static struct platform_driver iproc_mdio_driver = {
.driver = {
.name = "iproc-mdio",
.of_match_table = iproc_mdio_of_match,
},
.probe = iproc_mdio_probe,
.remove = iproc_mdio_remove,
};
module_platform_driver(iproc_mdio_driver);
MODULE_AUTHOR("Broadcom Corporation");
MODULE_DESCRIPTION("Broadcom iProc MDIO bus controller");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:iproc-mdio");
