blob: 6dcbf987d61b5fc93567b4a2b4d39a3b4f9840ce [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Broadcom BCM6368 mdiomux bus controller driver
*
* Copyright (C) 2021 Álvaro Fernández Rojas <noltari@gmail.com>
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mdio-mux.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 MDIOC_REG 0x0
#define MDIOC_EXT_MASK BIT(16)
#define MDIOC_REG_SHIFT 20
#define MDIOC_PHYID_SHIFT 25
#define MDIOC_RD_MASK BIT(30)
#define MDIOC_WR_MASK BIT(31)
#define MDIOD_REG 0x4
struct bcm6368_mdiomux_desc {
void *mux_handle;
void __iomem *base;
struct device *dev;
struct mii_bus *mii_bus;
int ext_phy;
};
static int bcm6368_mdiomux_read(struct mii_bus *bus, int phy_id, int loc)
{
struct bcm6368_mdiomux_desc *md = bus->priv;
uint32_t reg;
int ret;
__raw_writel(0, md->base + MDIOC_REG);
reg = MDIOC_RD_MASK |
(phy_id << MDIOC_PHYID_SHIFT) |
(loc << MDIOC_REG_SHIFT);
if (md->ext_phy)
reg |= MDIOC_EXT_MASK;
__raw_writel(reg, md->base + MDIOC_REG);
udelay(50);
ret = __raw_readw(md->base + MDIOD_REG);
return ret;
}
static int bcm6368_mdiomux_write(struct mii_bus *bus, int phy_id, int loc,
uint16_t val)
{
struct bcm6368_mdiomux_desc *md = bus->priv;
uint32_t reg;
__raw_writel(0, md->base + MDIOC_REG);
reg = MDIOC_WR_MASK |
(phy_id << MDIOC_PHYID_SHIFT) |
(loc << MDIOC_REG_SHIFT);
if (md->ext_phy)
reg |= MDIOC_EXT_MASK;
reg |= val;
__raw_writel(reg, md->base + MDIOC_REG);
udelay(50);
return 0;
}
static int bcm6368_mdiomux_switch_fn(int current_child, int desired_child,
void *data)
{
struct bcm6368_mdiomux_desc *md = data;
md->ext_phy = desired_child;
return 0;
}
static int bcm6368_mdiomux_probe(struct platform_device *pdev)
{
struct bcm6368_mdiomux_desc *md;
struct mii_bus *bus;
struct resource *res;
int rc;
md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL);
if (!md)
return -ENOMEM;
md->dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -EINVAL;
/*
* Just ioremap, as this MDIO block is usually integrated into an
* Ethernet MAC controller register range
*/
md->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!md->base) {
dev_err(&pdev->dev, "failed to ioremap register\n");
return -ENOMEM;
}
md->mii_bus = devm_mdiobus_alloc(&pdev->dev);
if (!md->mii_bus) {
dev_err(&pdev->dev, "mdiomux bus alloc failed\n");
return ENOMEM;
}
bus = md->mii_bus;
bus->priv = md;
bus->name = "BCM6368 MDIO mux bus";
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
bus->parent = &pdev->dev;
bus->read = bcm6368_mdiomux_read;
bus->write = bcm6368_mdiomux_write;
bus->phy_mask = 0x3f;
bus->dev.of_node = pdev->dev.of_node;
rc = mdiobus_register(bus);
if (rc) {
dev_err(&pdev->dev, "mdiomux registration failed\n");
return rc;
}
platform_set_drvdata(pdev, md);
rc = mdio_mux_init(md->dev, md->dev->of_node,
bcm6368_mdiomux_switch_fn, &md->mux_handle, md,
md->mii_bus);
if (rc) {
dev_info(md->dev, "mdiomux initialization failed\n");
goto out_register;
}
dev_info(&pdev->dev, "Broadcom BCM6368 MDIO mux bus\n");
return 0;
out_register:
mdiobus_unregister(bus);
return rc;
}
static int bcm6368_mdiomux_remove(struct platform_device *pdev)
{
struct bcm6368_mdiomux_desc *md = platform_get_drvdata(pdev);
mdio_mux_uninit(md->mux_handle);
mdiobus_unregister(md->mii_bus);
return 0;
}
static const struct of_device_id bcm6368_mdiomux_ids[] = {
{ .compatible = "brcm,bcm6368-mdio-mux", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, bcm6368_mdiomux_ids);
static struct platform_driver bcm6368_mdiomux_driver = {
.driver = {
.name = "bcm6368-mdio-mux",
.of_match_table = bcm6368_mdiomux_ids,
},
.probe = bcm6368_mdiomux_probe,
.remove = bcm6368_mdiomux_remove,
};
module_platform_driver(bcm6368_mdiomux_driver);
MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
MODULE_DESCRIPTION("BCM6368 mdiomux bus controller driver");
MODULE_LICENSE("GPL v2");