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// SPDX-License-Identifier: GPL-2.0
/* Qualcomm IPQ8064 MDIO interface driver
*
* Copyright (C) 2019 Christian Lamparter <chunkeey@gmail.com>
* Copyright (C) 2020 Ansuel Smith <ansuelsmth@gmail.com>
*/
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
/* MII address register definitions */
#define MII_ADDR_REG_ADDR 0x10
#define MII_BUSY BIT(0)
#define MII_WRITE BIT(1)
#define MII_CLKRANGE(x) ((x) << 2)
#define MII_CLKRANGE_60_100M MII_CLKRANGE(0)
#define MII_CLKRANGE_100_150M MII_CLKRANGE(1)
#define MII_CLKRANGE_20_35M MII_CLKRANGE(2)
#define MII_CLKRANGE_35_60M MII_CLKRANGE(3)
#define MII_CLKRANGE_150_250M MII_CLKRANGE(4)
#define MII_CLKRANGE_250_300M MII_CLKRANGE(5)
#define MII_CLKRANGE_MASK GENMASK(4, 2)
#define MII_REG_SHIFT 6
#define MII_REG_MASK GENMASK(10, 6)
#define MII_ADDR_SHIFT 11
#define MII_ADDR_MASK GENMASK(15, 11)
#define MII_DATA_REG_ADDR 0x14
#define MII_MDIO_DELAY_USEC (1000)
#define MII_MDIO_RETRY_MSEC (10)
struct ipq8064_mdio {
struct regmap *base; /* NSS_GMAC0_BASE */
};
static int
ipq8064_mdio_wait_busy(struct ipq8064_mdio *priv)
{
u32 busy;
return regmap_read_poll_timeout(priv->base, MII_ADDR_REG_ADDR, busy,
!(busy & MII_BUSY), MII_MDIO_DELAY_USEC,
MII_MDIO_RETRY_MSEC * USEC_PER_MSEC);
}
static int
ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset)
{
u32 miiaddr = MII_BUSY | MII_CLKRANGE_250_300M;
struct ipq8064_mdio *priv = bus->priv;
u32 ret_val;
int err;
miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
usleep_range(10, 13);
err = ipq8064_mdio_wait_busy(priv);
if (err)
return err;
regmap_read(priv->base, MII_DATA_REG_ADDR, &ret_val);
return (int)ret_val;
}
static int
ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data)
{
u32 miiaddr = MII_WRITE | MII_BUSY | MII_CLKRANGE_250_300M;
struct ipq8064_mdio *priv = bus->priv;
regmap_write(priv->base, MII_DATA_REG_ADDR, data);
miiaddr |= ((phy_addr << MII_ADDR_SHIFT) & MII_ADDR_MASK) |
((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);
regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
/* For the specific reg 31 extra time is needed or the next
* read will produce garbage data.
*/
if (reg_offset == 31)
usleep_range(30, 43);
else
usleep_range(10, 13);
return ipq8064_mdio_wait_busy(priv);
}
static const struct regmap_config ipq8064_mdio_regmap_config = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.can_multi_write = false,
/* the mdio lock is used by any user of this mdio driver */
.disable_locking = true,
.cache_type = REGCACHE_NONE,
};
static int
ipq8064_mdio_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct ipq8064_mdio *priv;
struct resource res;
struct mii_bus *bus;
void __iomem *base;
int ret;
if (of_address_to_resource(np, 0, &res))
return -ENOMEM;
base = devm_ioremap(&pdev->dev, res.start, resource_size(&res));
if (!base)
return -ENOMEM;
bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv));
if (!bus)
return -ENOMEM;
bus->name = "ipq8064_mdio_bus";
bus->read = ipq8064_mdio_read;
bus->write = ipq8064_mdio_write;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
bus->parent = &pdev->dev;
priv = bus->priv;
priv->base = devm_regmap_init_mmio(&pdev->dev, base,
&ipq8064_mdio_regmap_config);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
ret = of_mdiobus_register(bus, np);
if (ret)
return ret;
platform_set_drvdata(pdev, bus);
return 0;
}
static void ipq8064_mdio_remove(struct platform_device *pdev)
{
struct mii_bus *bus = platform_get_drvdata(pdev);
mdiobus_unregister(bus);
}
static const struct of_device_id ipq8064_mdio_dt_ids[] = {
{ .compatible = "qcom,ipq8064-mdio" },
{ }
};
MODULE_DEVICE_TABLE(of, ipq8064_mdio_dt_ids);
static struct platform_driver ipq8064_mdio_driver = {
.probe = ipq8064_mdio_probe,
.remove_new = ipq8064_mdio_remove,
.driver = {
.name = "ipq8064-mdio",
.of_match_table = ipq8064_mdio_dt_ids,
},
};
module_platform_driver(ipq8064_mdio_driver);
MODULE_DESCRIPTION("Qualcomm IPQ8064 MDIO interface driver");
MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
MODULE_AUTHOR("Ansuel Smith <ansuelsmth@gmail.com>");
MODULE_LICENSE("GPL");