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/*
* Driver for the MDIO interface of Marvell network interfaces.
*
* Since the MDIO interface of Marvell network interfaces is shared
* between all network interfaces, having a single driver allows to
* handle concurrent accesses properly (you may have four Ethernet
* ports, but they in fact share the same SMI interface to access
* the MDIO bus). This driver is currently used by the mvneta and
* mv643xx_eth drivers.
*
* Copyright (C) 2012 Marvell
*
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/wait.h>
#define MVMDIO_SMI_DATA_SHIFT 0
#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
#define MVMDIO_SMI_PHY_REG_SHIFT 21
#define MVMDIO_SMI_READ_OPERATION BIT(26)
#define MVMDIO_SMI_WRITE_OPERATION 0
#define MVMDIO_SMI_READ_VALID BIT(27)
#define MVMDIO_SMI_BUSY BIT(28)
#define MVMDIO_ERR_INT_CAUSE 0x007C
#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
#define MVMDIO_ERR_INT_MASK 0x0080
#define MVMDIO_XSMI_MGNT_REG 0x0
#define MVMDIO_XSMI_PHYADDR_SHIFT 16
#define MVMDIO_XSMI_DEVADDR_SHIFT 21
#define MVMDIO_XSMI_WRITE_OPERATION (0x5 << 26)
#define MVMDIO_XSMI_READ_OPERATION (0x7 << 26)
#define MVMDIO_XSMI_READ_VALID BIT(29)
#define MVMDIO_XSMI_BUSY BIT(30)
#define MVMDIO_XSMI_ADDR_REG 0x8
/*
* SMI Timeout measurements:
* - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
* - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
*/
#define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */
#define MVMDIO_SMI_POLL_INTERVAL_MIN 45
#define MVMDIO_SMI_POLL_INTERVAL_MAX 55
#define MVMDIO_XSMI_POLL_INTERVAL_MIN 150
#define MVMDIO_XSMI_POLL_INTERVAL_MAX 160
struct orion_mdio_dev {
void __iomem *regs;
struct clk *clk[3];
/*
* If we have access to the error interrupt pin (which is
* somewhat misnamed as it not only reflects internal errors
* but also reflects SMI completion), use that to wait for
* SMI access completion instead of polling the SMI busy bit.
*/
int err_interrupt;
wait_queue_head_t smi_busy_wait;
};
enum orion_mdio_bus_type {
BUS_TYPE_SMI,
BUS_TYPE_XSMI
};
struct orion_mdio_ops {
int (*is_done)(struct orion_mdio_dev *);
unsigned int poll_interval_min;
unsigned int poll_interval_max;
};
/* Wait for the SMI unit to be ready for another operation
*/
static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
struct mii_bus *bus)
{
struct orion_mdio_dev *dev = bus->priv;
unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
unsigned long end = jiffies + timeout;
int timedout = 0;
while (1) {
if (ops->is_done(dev))
return 0;
else if (timedout)
break;
if (dev->err_interrupt <= 0) {
usleep_range(ops->poll_interval_min,
ops->poll_interval_max);
if (time_is_before_jiffies(end))
++timedout;
} else {
/* wait_event_timeout does not guarantee a delay of at
* least one whole jiffie, so timeout must be no less
* than two.
*/
if (timeout < 2)
timeout = 2;
wait_event_timeout(dev->smi_busy_wait,
ops->is_done(dev), timeout);
++timedout;
}
}
dev_err(bus->parent, "Timeout: SMI busy for too long\n");
return -ETIMEDOUT;
}
static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
{
return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
}
static const struct orion_mdio_ops orion_mdio_smi_ops = {
.is_done = orion_mdio_smi_is_done,
.poll_interval_min = MVMDIO_SMI_POLL_INTERVAL_MIN,
.poll_interval_max = MVMDIO_SMI_POLL_INTERVAL_MAX,
};
static int orion_mdio_smi_read(struct mii_bus *bus, int mii_id,
int regnum)
{
struct orion_mdio_dev *dev = bus->priv;
u32 val;
int ret;
if (regnum & MII_ADDR_C45)
return -EOPNOTSUPP;
ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
if (ret < 0)
return ret;
writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
(regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
MVMDIO_SMI_READ_OPERATION),
dev->regs);
ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
if (ret < 0)
return ret;
val = readl(dev->regs);
if (!(val & MVMDIO_SMI_READ_VALID)) {
dev_err(bus->parent, "SMI bus read not valid\n");
return -ENODEV;
}
return val & GENMASK(15, 0);
}
static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id,
int regnum, u16 value)
{
struct orion_mdio_dev *dev = bus->priv;
int ret;
if (regnum & MII_ADDR_C45)
return -EOPNOTSUPP;
ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus);
if (ret < 0)
return ret;
writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
(regnum << MVMDIO_SMI_PHY_REG_SHIFT) |
MVMDIO_SMI_WRITE_OPERATION |
(value << MVMDIO_SMI_DATA_SHIFT)),
dev->regs);
return 0;
}
static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev)
{
return !(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY);
}
static const struct orion_mdio_ops orion_mdio_xsmi_ops = {
.is_done = orion_mdio_xsmi_is_done,
.poll_interval_min = MVMDIO_XSMI_POLL_INTERVAL_MIN,
.poll_interval_max = MVMDIO_XSMI_POLL_INTERVAL_MAX,
};
static int orion_mdio_xsmi_read(struct mii_bus *bus, int mii_id,
int regnum)
{
struct orion_mdio_dev *dev = bus->priv;
u16 dev_addr = (regnum >> 16) & GENMASK(4, 0);
int ret;
if (!(regnum & MII_ADDR_C45))
return -EOPNOTSUPP;
ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
if (ret < 0)
return ret;
writel(regnum & GENMASK(15, 0), dev->regs + MVMDIO_XSMI_ADDR_REG);
writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
(dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
MVMDIO_XSMI_READ_OPERATION,
dev->regs + MVMDIO_XSMI_MGNT_REG);
ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
if (ret < 0)
return ret;
if (!(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) &
MVMDIO_XSMI_READ_VALID)) {
dev_err(bus->parent, "XSMI bus read not valid\n");
return -ENODEV;
}
return readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0);
}
static int orion_mdio_xsmi_write(struct mii_bus *bus, int mii_id,
int regnum, u16 value)
{
struct orion_mdio_dev *dev = bus->priv;
u16 dev_addr = (regnum >> 16) & GENMASK(4, 0);
int ret;
if (!(regnum & MII_ADDR_C45))
return -EOPNOTSUPP;
ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus);
if (ret < 0)
return ret;
writel(regnum & GENMASK(15, 0), dev->regs + MVMDIO_XSMI_ADDR_REG);
writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) |
(dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) |
MVMDIO_XSMI_WRITE_OPERATION | value,
dev->regs + MVMDIO_XSMI_MGNT_REG);
return 0;
}
static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
{
struct orion_mdio_dev *dev = dev_id;
if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
MVMDIO_ERR_INT_SMI_DONE) {
writel(~MVMDIO_ERR_INT_SMI_DONE,
dev->regs + MVMDIO_ERR_INT_CAUSE);
wake_up(&dev->smi_busy_wait);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int orion_mdio_probe(struct platform_device *pdev)
{
enum orion_mdio_bus_type type;
struct resource *r;
struct mii_bus *bus;
struct orion_mdio_dev *dev;
int i, ret;
type = (enum orion_mdio_bus_type)of_device_get_match_data(&pdev->dev);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&pdev->dev, "No SMI register address given\n");
return -ENODEV;
}
bus = devm_mdiobus_alloc_size(&pdev->dev,
sizeof(struct orion_mdio_dev));
if (!bus)
return -ENOMEM;
switch (type) {
case BUS_TYPE_SMI:
bus->read = orion_mdio_smi_read;
bus->write = orion_mdio_smi_write;
break;
case BUS_TYPE_XSMI:
bus->read = orion_mdio_xsmi_read;
bus->write = orion_mdio_xsmi_write;
break;
}
bus->name = "orion_mdio_bus";
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
dev_name(&pdev->dev));
bus->parent = &pdev->dev;
dev = bus->priv;
dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
if (!dev->regs) {
dev_err(&pdev->dev, "Unable to remap SMI register\n");
return -ENODEV;
}
init_waitqueue_head(&dev->smi_busy_wait);
for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
dev->clk[i] = of_clk_get(pdev->dev.of_node, i);
if (IS_ERR(dev->clk[i]))
break;
clk_prepare_enable(dev->clk[i]);
}
dev->err_interrupt = platform_get_irq(pdev, 0);
if (dev->err_interrupt > 0 &&
resource_size(r) < MVMDIO_ERR_INT_MASK + 4) {
dev_err(&pdev->dev,
"disabling interrupt, resource size is too small\n");
dev->err_interrupt = 0;
}
if (dev->err_interrupt > 0) {
ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
orion_mdio_err_irq,
IRQF_SHARED, pdev->name, dev);
if (ret)
goto out_mdio;
writel(MVMDIO_ERR_INT_SMI_DONE,
dev->regs + MVMDIO_ERR_INT_MASK);
} else if (dev->err_interrupt == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
goto out_mdio;
}
ret = of_mdiobus_register(bus, pdev->dev.of_node);
if (ret < 0) {
dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
goto out_mdio;
}
platform_set_drvdata(pdev, bus);
return 0;
out_mdio:
if (dev->err_interrupt > 0)
writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
if (IS_ERR(dev->clk[i]))
break;
clk_disable_unprepare(dev->clk[i]);
clk_put(dev->clk[i]);
}
return ret;
}
static int orion_mdio_remove(struct platform_device *pdev)
{
struct mii_bus *bus = platform_get_drvdata(pdev);
struct orion_mdio_dev *dev = bus->priv;
int i;
if (dev->err_interrupt > 0)
writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
mdiobus_unregister(bus);
for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
if (IS_ERR(dev->clk[i]))
break;
clk_disable_unprepare(dev->clk[i]);
clk_put(dev->clk[i]);
}
return 0;
}
static const struct of_device_id orion_mdio_match[] = {
{ .compatible = "marvell,orion-mdio", .data = (void *)BUS_TYPE_SMI },
{ .compatible = "marvell,xmdio", .data = (void *)BUS_TYPE_XSMI },
{ }
};
MODULE_DEVICE_TABLE(of, orion_mdio_match);
static struct platform_driver orion_mdio_driver = {
.probe = orion_mdio_probe,
.remove = orion_mdio_remove,
.driver = {
.name = "orion-mdio",
.of_match_table = orion_mdio_match,
},
};
module_platform_driver(orion_mdio_driver);
MODULE_DESCRIPTION("Marvell MDIO interface driver");
MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:orion-mdio");
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